A mechanical engineering student at EPFL in Switzerland wanted to understand the reason behind the formation of a “foam volcano” after tapping the neck of a bottle of beer. He studied the phenomenon with a high-speed camera and compared it to the outcome of applying the same action to sparkling water. His work offers insights into the behavior of cavitation nuclei.
A new study has investigated the effects of small...
More than a decade ago, news of a Namibian desert...
Using something called a microchannel heat sink to simulate the warm environment of a working computer, researchers in Malaysia have analyzed three nanofluids for the traits that are important in an effective coolant. The results of their study show that the nanofluids, which are made of metallic nanoparticles that have been added to a liquid, such as water, all performed better than water as coolants, with one mixture standing out.
Known as the “world's longest experiment”, an experiment at the University of Queensland in Australia was famous for taking ten years for a drop of pitch, a black, sticky material, to fall from a funnel. A new test in the U.K. is using a different bitumen, or pitch, which is 30 times less viscous than the Queensland experiment, so that the flow can be seen at a faster rate and hopefully provide more insights.
Whenever there is a major spill of oil into water, the two tend to mix into a suspension of tiny droplets, called an emulsion, that is extremely hard to separate and can cause severe damage to ecosystems. A new membrane developed by Massachusetts Institute of Technology researchers can separate even these highly mixed fine oil-spill residues.
Physicists in Europe have solved a mystery that has puzzled scientists for half a century. it has long been known that the distance between the graphene oxide layers depends on the humidity, not the actual amount of water added. But now, with the help of powerful microscopes, it can be seen how distance between graphite oxide layers gradually increases when water molecules are added, and why this phenomenon occurs.
A physicist in Russia, Alexander Rozhkov, has presented theoretical calculations which indicate the possible existence of fermionic matter in a previously unknown state. It is defined as a 1-D liquid, which cannot be described within the framework of existing models. According to Rozhkov, the 1-D liquid state of matter is not necessarily one that can be observed with the naked eye on a macroscopic scale.
Simple solid-state lasers consist of only one material. But quantum cascade lasers are made of a perfectly optimized layer system of different materials so the wavelength of the laser can be tuned. Now a method has been developed in Austria to create a laser and a detector at the same time, on one single chip, in such a way that the wavelength of the laser perfectly matches the wavelength to which the detector is sensitive.
Essential oils have boomed in popularity as more people seek out alternatives to replace their synthetic cleaning products, anti-mosquito sprays and medicines. Now scientists are tapping them as candidates to preserve food in a more consumer-friendly way. Recent research has led to new edible films containing oils from clove and oregano that preserve bread longer than commercial additives.
Bacteria use threadlike appendages, called pili, to creep along a surface, and some disease-causing microbes extend pili in all directions to move. But until now researchers have been unable to explain why bacteria like these are able to travel in a straight line consistently. A new model developed to describe this movement shows that bacteria do not act as randomly as they appear to when moving.
Although lubricants for machinery are widely used, almost no fundamental innovations for this type of product has been made in the last 20 years, according researchers in Germany who have been working on a new class of lubricating substance. Their new liquid crystalline lubricant enable nearly frictionless sliding because although it is a liquid, the molecules display directional properties like crystals do.
Brigham Young Univ. engineering professors Julie Crockett and Dan Maynes have created a sloped channel that is super-hydrophobic, and causes water to bounce like a ball as it rolls down the ramp. Their recent study finds surfaces with a pattern of microscopic ridges or posts, combined with a hydrophobic coating, produces an even higher level of water resistance, depending on how the water hits the surface.
A simple new technique to form interlocking beads of water in ambient conditions could prove valuable for applications in biological sensing, membrane research and harvesting water from fog. Researchers have developed a method to create air-stable water droplet networks known as droplet interface bilayers. These interconnected water droplets have many roles in biological research because their interfaces simulate cell membranes.
Scientists at Rice Univ. have mixed very low concentrations of diamond nanoparticles with mineral oil to test the nanofluid’s thermal conductivity and how temperature would affect its viscosity. They found it to be much better than nanofluids that contain higher amounts of oxide, nitride or carbide ceramics, metals, semiconductors, carbon nanotubes and other composite materials. In short, it is the best nanofluid for heat transfer.
A key to realizing commercial-scale artificial photosynthesis technology is the development of electrocatalysts that can efficiently and economically carry out water oxidation reaction that is critical to the process. Heinz Frei, a chemist Lawrence Berkeley National Laboratory, has been at the forefront of this research effort. His latest results represent an important step forward.
Scientists are reporting the development of a novel metal ink made of small sheets of copper that can be used to write a functioning, flexible electric circuit on regular printer paper. Their report on the conductive ink, which could pave the way for a wide range of new bendable gadgets, such as electronic books that look and feel more like traditional paperbacks, appears in ACS Applied Materials & Interfaces.
In earlier studies, a team from the Univ. of Pennsylvania produced nanoscale grids and rings of “defects,” or useful disruptions in the repeating patterns found in liquid crystals. Their latest study adds a more complex pattern out of an even simpler template: A 3-D array in the shape of a flower. This advances the use of liquid crystals as a medium for assembling structures.
In a sort of biological "spooky action at a distance," water in a cell slows down in the tightest confines between proteins and develops the ability to affect other proteins much farther away, Univ. of Michigan researchers have discovered. The finding could provide insights into how and why proteins clump together in diseases such as Alzheimer's and Parkinson's.
Scientists from the Hamburg Center for Free-Electron Laser Science have devised a novel way to boil water in less than a trillionth of a second. The theoretical concept, which uses terahertz radiation but has not yet been demonstrated in practice, could heat a small amount of water by as much as 600 C in just half a picosecond.
A researcher team from Spain and Italy say that when envisioning in vivo microrobots of the future, we should forget cogwheels, pistons and levers. These miniature robots will be soft, and behave much like euglenids, tiny unicellular aquatic animals. Their work in studying these creatures have given them insights on how to design soft robots with effective mechanical structures.
Researchers have combined cutting-edge experimental techniques and computer simulations to find a new way of predicting how water dissolves crystalline structures like those found in natural stone and cement. The research could have wide-ranging impacts in diverse areas, including water quality and planning, environmental sustainability, corrosion resistance and cement construction.
The outer shell of a droplet of oil on a surface has a thin skin which allows it to hold its shape like a small dome. Researchers at the Univ. of Missouri have developed a technique to form a virtual wall for oily liquids that will help confine them to a certain area, aiding researchers who are studying these complex molecules. The finding could also help halt industrial oil spills.
Oil and water don’t mix, as any chemist or cook knows. Tom Russell, a polymer scientist from the Univ. of Massachusetts who now holds a visiting faculty appointment with Lawrence Berkeley National Laboratory’s Materials Sciences Div., is using that chemical and culinary truth to change the natural spherical shape of liquid drops into ellipsoids, tubes and even fibrous structures similar in appearance to glass wool.
Those who study hydrophobic materials are familiar with a theoretical limit on the time it takes for a water droplet to bounce away from such a surface. But Massachusetts Institute of Technology researchers have now found a way to burst through that perceived barrier, reducing the contact time by at least 40%.
Stingrays swim through water with such ease that researchers from the Univ. at Buffalo and Harvard Univ. are studying how their movements could be used to design more agile and fuel-efficient unmanned underwater vehicles. The vehicles could allow researchers to more efficiently study the mostly unexplored ocean depths, and they could also serve during clean up or rescue efforts.
An interdisciplinary team of University of Pennsylvania researchers has already developed a technique for controlling liquid crystals by means of physical templates and elastic energy, rather than the electromagnetic fields that manipulate them in televisions and computer monitors. They envision using this technique to direct the assembly of other materials, such as nanoparticles.
To tune how much light is received by optics, conventional devices use mechanical contraptions like the blades that form apertures in cameras. Engineers from the Univ. of Freiburg in Germany have made these solutions unnecessary by replacing conventional, solid lenses with the combination of a malleable lens and a liquid iris-like component.
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