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A metamaterial makes an object undetectable by sonar.
After stealth aircraft, submarines will soon be detected by sonar? Is that suggested by the work of a team from the University of Illinois at Urbana-Champaign, United States. Nicholas Fang and his colleagues have designed an “invisibility cloak” ultrasound: when in water, an ultrasonic wave encounters an object surrounded by the cloak, it spreads like there was no obstacle.
In recent years, invisibility cloaks, devices which deflect the waves so as to conceal an object large compared to their wavelength, are an active area of research. Prototypes for the electromagnetic waves or small ripples on the surface of a liquid have already been made. The keys of these devices are metamaterials – materials that are structured on a scale comparable to the wavelengths that we want to control.
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It has been proven in research that the crystalline structures formed by microscopic particles that have been developed on a surface with negative curvature can develop linear defects comparable to the folds of fabric.
The results of this research will facilitate the achievement of broader explorations of defects in curved spaces, including potential applications in the design of new materials.
The problem of coating a curved surface with hexagons is relatively familiar to us by the existence of soccer balls and geodesic domes, in which pentagons are added to a spherical curvature (positive) in a way that fit.
The particles interact with each other and form hexagonal patterns in a plane (colloidal crystals) take these and other topological defects when grown in a field.
Physicist William Irvine, University of Chicago, and colleagues have developed an experimental system that allows them to investigate crystalline order on surfaces with variable spatial curvature, both positive and negative.
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A team of researchers from eight agencies, including the University of Tohoku and intermetallics, a company specializing in research and development of permanent magnets, has developed a new method of manufacturing sintered magnets [1] Neodymium-Iron- Boron (NdFeB) which reduces the amount employed dysprosium (Dy).
NdFeB magnets are currently the most powerful permanent magnets commercially available. They are widely used in motors for hybrid vehicles and generators in wind turbines. As their name suggests, they consist of a sintered powder of an alloy of iron (Fe), neodymium (Nd) and boron (B). They also contain small quantities of dysprosium to improve their operating temperature. About a third of their membership is composed of rare earth (Nd, Dy), whose production is ensured by a very limited number of countries. Thus, the third of neodymium and almost 100% of dysprosium consumed in Japan comes from China, which recently decided to limit its exports. But if the supply chain neodymium is being stabilized, the archipelago remains highly dependent on its neighbor in terms dysprosium. In 2008, the Organization for the Development of New Energy and Industrial Technology (NEDO) has launched a “development project materials to replace rare metals’ that sets many goals is a reduction of 30% by 2011 Consumer dysprosium [2]. The new method described in this article was developed under this project.
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A team of Japanese researchers led by Professor Hiroshi KITAGAWA of Kyoto University has succeeded in producing a new alloy that could replace palladium, a rare metal used among others as a catalyst, particularly in the exhaust pipes of vehicles.
Palladium (Pd) is the 46th element in the periodic table of elements. It is located between rhodium (Rh) and silver (Ag), which therefore have less of an electron respectively and more than palladium. The researchers’ idea is to create an alloy of two metals to produce particles in which the electrons of the atoms that compose them are “mixed” orbitals and form similar to those of palladium atoms.
The problem is that the rhodium and silver do not mix, even at extremely high temperatures. The team of Professor KITAGAWA has developed a new manufacturing process of transforming into fine droplets in an aqueous solution containing equal amounts of silver and rhodium and gradually mix with hot alcohol. The resulting particles have a diameter of 10 nm and contain the same number of atoms of two metals.
The researchers verified that the new alloy has the same catalytic properties as palladium. It also has a similar capacity for storing hydrogen. Palladium is indeed able to absorb reversibly up to 900 times its volume of hydrogen gas.
Professor KITAGAWA estimated that production of this new material will be difficult to industrialize. However, its work should enable the production of substitutes palladium using the same method applied to other elements.
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The collaboration between a team of researchers from the University of Aveiro, and a team from the Institute of Materials Science of Aragon (CSIC-UNIZAR), helped develop a luminescent nanotermometro with unique properties that allow us to study the biochemistry of micro-thermal processes occurring within the cell. The results of this collaboration have just appeared in Advanced Materials, one of the most prestigious scientific journals in materials science.
The temperature measurement is essential in many scientific and technological developments, which now represents 75% -80% of the sensor market worldwide. In the field of nanoscale was still necessary to develop temperature sensors, since in general the traditional thermometers are not suitable for measuring the temperature of a section of a material of a size less than 10 micrometers (100 times smaller than a millimeter).
Because of this limitation has encouraged the development of new thermometers that do not require direct contact with the material they want to know the temperature and micrometer and nanometer spatial resolution (1 million times smaller than a millimeter).
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Researchers at the Institute of Materials Science of Seville (CSIC-US) and the University of Malaga (UMA) have created a biodegradable plastic from the skin of tomato with applications in the field of nutrition and health.
Andalusian experts took as a reference the main component of the epidermis of the skin of this fruit: a biopoliéster called cutin which is the matrix of the cuticle layer covering the surface of leaves, stems and fruits of woody no higher plants. The main function of this biopolymer is to preserve the loss of water from inside cells and to act as an interface between the plant and the external environment.
Jose Jesus Benitez Jimenez, project manager, said “cutin product is seen as a biocompatible, biodegradable and nontoxic nature itself used as a protective layer of fruit and leaves, and therefore can be adapted and used artificially commercial material for food packaging. “ “Surprisingly, despite being part of a wide range of plant tissues, the evolutionary process has led to the chemical composition of plant cutin is very homogeneous,” stresses.
Among the key design of this new material include biochemical characteristics in the formation of the skin. “It described a route that we used in the preparation of the final product. The monomers, obtained by manipulating the skin in an alkaline medium, have some intrinsic physical and chemical properties that make it best suited to succeed in biopoliéster the operation of the natural environment, “he says. “We just have to submit final product to certain physical and chemical conditions for a plastic that fits our needs.”
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Alejandro Ureña is professor of materials science and metallurgical engineering at the Universidad Rey Juan Carlos (Rey Juan Carlos University) in Madrid. Expert in joining processes of advanced materials for applications in transport and ESTRUMAT program coordinator, explains the challenges to make materials nanorreforzados and make more environmentally friendly transport systems.
How important are the materials in reducing pollution?
Any transport is comprised of materials such as metals, steel, aluminum, metal composites or plastics. The selection of these materials is made from a functional standpoint, that is, to maintain some tension, some loads and absorb energy to prepare themselves to prevent collisions. In turn, a moving mass transport and consume energy. Currently in all transport systems use energy from fossil fuels which produces CO2 when consumed. We have to build more resilient materials and lighter. Thus, our cars and airplanes will weigh less and consume less energy. The approach from the energy of the materials is to optimize the behavior of materials, developing new alloys, new composite materials and lighter and more durable.
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Thirteen companies, 5 research centers and Tecnalia Forma0 involved in the project, led by Seat and managed by CTM Foundation Technology Centre, aimed to develop lighter and safer vehicles. The research has focused on new materials and manufacturing processes that allow components to form high strength steels.
Forma0 project that has lasted 4 years, and was recently closed, is led by SEAT and managed by CTM Foundation Technology Centre. Tecnalia participates in this initiative aimed at developing lighter and safer vehicles, along with 12 other companies – such as ANTEC Vizcaya y 5 research centers.
The project has focused on the research of new materials and manufacturing processes that allow components to form high strength steels (AHSS), mainly for the automotive industry. Research on high-strength steels aims to achieve lighter and safer vehicles, moreover, allow to reduce consumption, emissions and weight of such vehicles, and improve impact resistance.
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Many human behaviors are conditioned by mechanisms of reward and punishment, although each person acts differently to these stimuli. In fact, there are people who are more likely to seek rewards or pleasures and change others show stronger tendencies to avoid losses or negative life events.
The reason for these individual differences in the connections of a specific area of the brain, according to a study recently published in The Journal of Neuroscience. This work has involved researchers from the Institute of Biomedical Research of Bellvitge (IDIBELL) and the Department of Basic Psychology at the Universitat de Barcelona Estela House (now the Institute of Cognitive Neuroscience, UCL, London) and Antoni Rodríguez Fornells (ICREA researcher .) The research results provide new evidence on individual differences observed in how people can be more or less likely to seek rewards or pleasures or avoid negative or unpleasant situations.
The researchers studied the brain activity of a group of 35 healthy volunteers as they played and bet to earn money.
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Published in the journal Physical Review Letters A team from the Centre for Energy, Environment and Technology (CIEMAT) has developed a technique capable of inhibiting the formation of carbon-tritium deposits based on the injection of ammonia in the divertor region without disturbing the plasma characteristics merger.
Although the materials based on carbon fiber were initially chosen for the elements of maximum interaction with the plasma in the divertor of ITER, being built in Cadarache, France, for its magnificent physical-chemical properties, the problem associated with high retention of tritium from carbon film formation in areas of difficult access for cleaning has led to their exclusion in the active phase of operation of this device (ie, producing fusion power).
Recently, however, an international team led by Francisco Tabares, group interaction-Wall Plasma Fusion National Laboratory, CIEMAT, has developed a technique capable of completely inhibit the formation of deposits of carbon-based tritium injection of ammonia in the divertor region so as not to disturb the characteristics of fusion plasma.
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After stealth aircraft, submarines will soon be detected by sonar? Is that suggested by the work of a team from the University of Illinois at Urbana-Champaign, United States. Nicholas Fang and his colleagues have designed an “invisibility cloak” ultrasound: when in water, an ultrasonic wave encounters an object surrounded by the cloak, it spreads like there was no obstacle.
Palladium (Pd) is the 46th element in the periodic table of elements. It is located between rhodium (Rh) and silver (Ag), which therefore have less of an electron respectively and more than palladium. The researchers’ idea is to create an alloy of two metals to produce particles in which the electrons of the atoms that compose them are “mixed” orbitals and form similar to those of palladium atoms.