Sweaty hands can reduce the effectiveness of bacteria-fighting brass objects in hospitals and schools after just an hour of coming into contact with them, according to scientists at the Univ. of Leicester.
Copper found in everyday brass items such as door handles and water taps has an antimicrobial effect on bacteria and is widely used to prevent the spread of disease, John Bond from the Univ. of Leicester’s Department of Chemistry has discovered that peoples’ sweat can, within an hour of contact with the brass, produce sufficient corrosion to adversely affect its use to kill a range of microorganisms, such as those that might be encountered in a hospital and that can be easily transferred by touch or by a lack of hand hygiene.
Lawrence Livermore National Laboratory researchers have developed a new and more efficient approach to a challenging problem in additive manufacturing using selective laser melting — the selection of appropriate process parameters that result in parts with desired properties.
Selective laser melting (SLM) is a powder-based, additive manufacturing process where a 3-D part is produced, layer by layer, using a high-energy laser beam to fuse the metal powder particles. Some SLM applications require parts that are very dense, with less than 1 percent porosity, as the pores or voids are the weakest part of the material and most likely would result in failure.
Researchers have announced the first ever method for controlling the growth of metal-crystals from single atoms.
Published in the journal Nature Communications and developed at the Univ. of Warwick, the method, called nanocrystallometry, allows for the creation of precise components for use in nanotechnology. Prof. Peter Sadler from the Univ.’s Department of Chemistry comments that, “The breakthrough with nanocrystallometry is that it actually allows us to observe and directly control the nanoworld in motion.”
Photocatalysis — catalysis assisted by light — is a promising route to convert solar energy into chemical fuels. Particularly appealing is the possibility to use photocatalysis to split water molecules into molecular hydrogen. Although photocatalysis has been around for many years, the search for viable photocatalysts to facilitate the splitting of water molecules continues to date.
Photocatalysts are most often semiconductors, with metals such as platinum or gold added to promote their activity. However, these metals (or “promoters”) are expensive. There is a need, therefore, to find more economical alternatives.
Scientists from the Univ. of the Philippines, Los Baños have discovered a new plant species with an unusual lifestyle — it eats nickel for a living — accumulating up to 18,000 ppm of the metal in its leaves without itself being poisoned, says Prof. Edwino Fernando, lead author of the report. Such an amount is 100 to 1,000 times higher than in most other plants. The study was published in Pensoft Publishers’ open access journal PhytoKeys.
The new species is called Rinorea niccolifera, reflecting its ability to absorb nickel in very high amounts. Nickel hyperaccumulation is such a rare phenomenon with only about 0.5–1 percent of plant species native to nickel-rich soils having been recorded to exhibit the ability. Throughout the world, only about 450 species are known with this unusual trait, which is still a small proportion of the estimated 300,000 species of vascular plants.
Copper is so valuable that its theft from worksites and power substations has become a national problem. Replacing the lost copper with new metal produced by the traditional method of cooking copper sulfide ores requires a multistep process to extract the copper and produces troublesome byproducts. Antoine Allanore, the Thomas B. King Assistant Professor of Metallurgy at MIT, wants to simplify copper extraction and eliminate noxious byproducts through electrolysis.
"If you look at the energy consumption of a copper smelter today, it’s enormous,” Allanore says. “They are dependent on electricity already to exist. My approach asks, why don’t we try to do 100 percent electrical, starting from the concentrate and ending with the metal product, if I can use electricity to be more efficient as well as more environmentally friendly?"
Filter Recover 80 Percent of Gold in Cell Phone Scrap
Cell phone scrap can contain precious metals, such as gold and copper. VTT Technical Research Centre of Finland has developed a biological filter made of mushroom mycelium mats enabling recovery of as much as 80 percent of the gold in electronic scrap. Extraction of copper from circuit board waste, on the other hand, can be enhanced significantly by floating the crushed and sieved material.
Although research into the biological methods is active, these are still rarely used in metal recovery chains. In a European “Value from Waste” project, VTT developed both biological and mechanical pre-treatment methods for more efficient recovery of precious metals from electronic waste. Other methods developed by researchers included recovery of gold from dissolved materials by biosorption and extraction, using as few harmful chemicals as possible.
Drexel Univ. researchers are turning some of the basic tenets of chemistry and physics upside down to cut a trail toward the discovery of a new set of materials. They’re called “polar metals” and, according to many of the scientific principles that govern the behavior of atoms, they probably shouldn’t exist.
James Rondinelli, a professor in the College of Engineering, and Danilo Puggioni, a postdoctoral researcher in the College, have shed light on this rare breed of electrically conductive polar metal — whose atomic makeup actually has more in common with a drop of water than a flake of rust — using an advanced computing method called density functional theory.
Titanium alloy golf clubs can cause dangerous wildfires, UC Irvine scientists say. When a club coated with the lightweight metal is swung and strikes a rock, it creates sparks that can heat to more than 3,000 F for long enough to ignite dry foliage, according to findings published recently in the peer-reviewed journal Fire and Materials.
Orange County, Calif., fire investigators asked UC Irvine to determine whether such clubs could have caused blazes at Shady Canyon Golf Course in Irvine and Arroyo Trabuco Golf Club in Mission Viejo a few years ago.
Using an inexpensive inkjet printer, Univ. of Utah electrical engineers produced microscopic structures that use light in metals to carry information. This new technique, which controls electrical conductivity within such microstructures, could be used to rapidly fabricate superfast components in electronic devices, make wireless technology faster or print magnetic materials.
MIT chemists have devised a way to trap carbon dioxide and transform it into useful organic compounds, using a simple metal complex.
More work is needed to understand and optimize the reaction, but one day this approach could offer an easy and inexpensive way to recapture some of the carbon dioxide emitted by vehicles and power plants, says Christopher Cummins, an MIT professor of chemistry and leader of the research team.
Mount Kinabalu is well known to climbers and adventurers all over the world. Now, a Univ. of Queensland researcher is putting the Borneo mountain region on the map for trees that contain some of the world’s highest concentrations of nickel.
With temperatures ranging from five to 35 C, the World Heritage Site has a hugely diverse ecosystem and is home to more than 5,000 plant species in just 1,200 km2. In comparison there are 25,000 plant species in all of Australia (7.7 million km2).
OLEDs are already used in the displays of smart phones or digital cameras today. They offer an especially bright image with high contrast, but come with a serious drawback: typically, only one quarter of the electrical energy invested in running the device is actually converted into light. This ratio can be raised by adding traces of noble metals such as platinum or iridium to the active material, but these elements are rare and very expensive. Making high-quality OLEDs is therefore a rather costly business.
This could change in the near future. The scientists from the Univ. of Bonn, Regensburg and the U.S. have demonstrated a novel type of OLED, which shows potential for high conversion efficiencies without having to resort to noble metals. OLED displays could well get quite a bit cheaper soon.
The ancient alchemists sought to transform base metals, like lead, into precious gold. Now a new process developed at the Univ. of Illinois at Chicago suggests that base metals may be worth more than their weight in gold — as catalysts in the manufacture of countless products made from petroleum-based raw materials.
The process is described online in the Journal of the American Chemical Society. Pharmaceuticals, electronic components, plastics and fuels are just some of the goods based on petroleum, a hydrocarbon molecule. But to use petroleum, the chemical bonds between its hydrogen and carbon atoms must first be broken so that other elements can be added. Breaking those bonds — other than by burning — is a challenge to chemists.