Showing Spotlights 1249 - 1256 of 2140 in category (newest first):
The concept of self-healing has become a popular theme in the field of material science. The whole concept of 'smart' materials that react on external impact - pH, humidity changes, or distortion of the coating integrity - and repair themselves has experienced a tremendous boost with the advent of nanotechnology. The nanoscale multilayer structure of a coating, in which the components are integrated and mutually reactive, is a main point in sophisticated and strong corrosion protection. Researchers have now proposed a new approach to self-healing polymer coating systems based on an electrospun coaxial healing agent. Electrospinning offers a number of unique opportunities. Most significantly, the location and concentration of the healing component can be spatially varied.
Mar 29th, 2010
It has proven difficult to directly manufacture functional nanostructures and nanodevices with predetermined designs using bottom-up processes alone. So far, developing top-down machining techniques capable of fabricating structural/functional nanostructures and nanodevices appears to be indispensable, but mechanical machining tools with nanometer precision are still lacking. A grand challenge in nanotechnology is to machine three-dimensional nanostructures in a controllable and reproducible fashion. That begs the question if traditional top-down mechanical machining can also be realized at the nanoscale. So far, the conventional wisdom has been that traditional top-down mechanical machining like cutting and milling using a lathe is impossible at the nanoscale. Nanotechnologists considered most of the traditional top-down approaches as not applicable for fabricating nanostructure and nanodevices. However, as it turns out, there still is room at the bottom for traditional mechanical machining.
Mar 26th, 2010
Bioethanol, unlike petroleum, is a form of renewable energy that can be produced from common agricultural feedstocks such as sugar cane or corn. Ethanol is already widely used in siome countries, mainly as biofuel additive for gasoline. The tremendous hype about bioethanol in the past few years has now been followed by a debate about how useful bioethanol actually can replace gasoline. Concerns about its production and use relate to the large amount of arable land required for crops, as well as the energy and pollution balance of the whole cycle of ethanol production. Recent developments with cellulosic ethanol production and commercialization may allay some of these concerns. It offers the promise that any plant material, from grass to wood, and not just edible crops, could be used in the production of ethanol fuels. Consequently, cellulosic ethanol could allow ethanol fuels to play a much bigger role in the future than previously thought. With regard to cellulosic production and commercialization, bioethanol production from woody biomass by enzymatic hydrolysis of cellulosic components and fermentation has attracted much attention.
Mar 25th, 2010
Last year, NT-MDT Co. invited its AFM probe users to take part in an open contest of images obtained with their probes. Though equipment is important in gathering a great AFM image, the result also depends on the probe being used. The purpose of the contest was to compile the most intriguing images collected from ventures into the nano-universe with AFM tips. Another aim of the ProIMAGE Contest was to show a great variety of scientific and artistic results obtained with a wide range of specialized probes. A gallery of all images submitted to the contest, which now is closed, and the six winners can be seen on the ProIMAGE webpages. Here is a random selection of some visually stunning images from the 150 contest submissions.
Mar 24th, 2010
Freshwater could become the oil of the 21st century - scarce, expensive and fought over. While over 70 per cent of the Earth's surface is covered by water, most of it is unusable for human consumption. Technological advances have made desalination and demineralization feasible - albeit expensive - solutions for increasing the world's supply of freshwater. However, nanotechnology- based water purification devices have the potential to transform the field of desalination. Researchers have now demonstrated a new, efficient and fouling-free desalination process based on the ion concentration polarization (ICP) phenomenon - a fundamental electrochemical transport phenomenon that occurs when an ion current is passed through ion-selective membranes - for direct desalination of sea water.
Mar 22nd, 2010
Materials that can produce electricity are at the core of piezoelectric research and the vision of self-powering machines and devices. With the emergence of nanotechnology and the use of nanomaterials, the field of piezoelectrics and nanopiezotronics has experienced a lot of new and interesting research efforts. A recent study, for instance, has demonstrated that the small vibrational energy waste generated in the environment from noise, wind power, running water, or water wave action can be scavenged or harvested as a driving force for direct water splitting. The researchers propose a new piezoelectrochemical mechanism for the direct conversion of mechanical energy to chemical energy and subsequently the splitting of water into hydrogen and oxygen.
Mar 19th, 2010
Artificial photosynthesis can offer a clean and portable source of energy supply as durable as the sunlight. Using sunlight to split water molecules and form hydrogen fuel is one of the most promising tactics for kicking our carbon habit. Of the possible methods, nature provides the blueprint for converting solar energy in the form of chemical fuels. A natural leaf is a synergy of the elaborated structures and functional components to produce a highly complex machinery for photosynthesis in which light harvesting, photoinduced charge separation, and catalysis modules combined to capture solar energy and split water into oxygen and hydrogen efficiently. Chinese researchers have now demonstrated the design of an efficient, cost-effective artificial system to mimic photosynthesis by copying the elaborate architectures of green leaves, replacing the natural photosynthetic pigments with man-made catalysts and thereby realizing water splitting- a major advance in energy conversion.
Mar 18th, 2010
It has been known for several years that carbon nanotubes would heat, ignite and luminesce upon exposure to certain types of electromagnetic radiation, including laser light. However, no one expected any form of fullerenes to do the same thing. Until now. A team at the University of Florida has discovered that functionalized fullerenes heat, ignite, glow and transform into other carbon nanostructures such as carbon nanotubes upon exposure to low-intensity laser light. This is the first time these findings have been published. A possible explanation for the optical heating and ignition phenomena that have been observed is a distortion of the symmetrical cage structure of the fullerenes.
Mar 17th, 2010