Chinese commercial rocket company Orienspace has raised tens of millions of dollars in Series B+ financing as it moves towards a key test flight.
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The White House has moved to eliminate employee unions at NASA, among other agencies, on national security grounds.
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It’s well documented that a frothy head on a beverage can stop the liquid from sloshing around and onto the floor – it’s one reason why when walking around with coffee, it swills around more than beer, for example.
When it comes to beer, a clear sign of a good brew is a big head of foam at the top of a poured glass.
Beer foam is made of many small bubbles of air, separated from each other by thin films of liquid. These thin films must remain stable, or the bubbles will pop, and the foam will collapse.
What holds these thin films together is not completely understood and is likely conglomerates of proteins, surface viscosity or the presence of surfactants – molecules that reduce surface tension and are found in soaps and detergents.
To find out more, researchers from ETH Zurich and Eindhoven University of Technology (EUT) investigated beer-foam stability for different types of beers at varying stages of the fermentation process.
They found that for single-fermentation beers, the foams are mostly held together with the surface viscosity of the beer. This is influenced by proteins in the beer – the more they contain the more viscous the film and more stable the foam will be.
“We can directly visualize what’s happening when two bubbles come into close proximity,” notes EUT material scientist Emmanouil Chatzigiannakis. “We can directly see the bubble’s protein aggregates, their interface, and their structure.”
When it comes to double-fermented beers, however, the proteins in the beer are altered slightly by yeast cells and come together to form a two-dimensional membrane that keeps foam intact longer.
The head was found to be even more stable for triple-fermented beers, which include Belgium Trappist beers. The proteins change further and behave like a surfactant that stabilizes the bubbles.
The team say that the finding of how the fermentation process alters the stability of bubbles could be used to produce more efficient ways of creating foams – or identify ways to control the amount of froth so that everyone can pour a perfect glass of beer every time. Cheers!
The post Why foamy heads on Belgium beers last so long appeared first on Physics World.
Nuclear scientists at the Lawrence Berkeley National Laboratory (LBNL) in the US have produced and identified molecules containing nobelium for the first time. This element, which has an atomic number of 102, is the heaviest ever to be observed in a directly-identified molecule, and team leader Jennifer Pore says the knowledge gained from such work could lead to a shake-up at the bottom of the periodic table.
“We compared the chemical properties of nobelium side-by-side to simultaneously produced molecules containing actinium (element number 89),” says Pore, a research scientist at LBNL. “The success of these measurements demonstrates the possibility to further improve our understanding of heavy and superheavy-element chemistry and so ensure that these elements are placed correctly on the periodic table.”
The periodic table currently lists 118 elements. As well as vertical “groups” containing elements with similar properties and horizontal “periods” in which the number of protons (atomic number Z) in the nucleus increases from left to right, these elements are arranged in three blocks. The block that contains actinides such as actinium (Ac) and nobelium (No), as well as the slightly lighter lanthanide series, is often shown offset, below the bottom of the main table.
Arranging the elements this way is helpful because it gives scientists an intuitive feel for the chemical properties of different elements. It has even made it possible to predict the properties of new elements as they are discovered in nature or, more recently, created in the laboratory.
The problem is that the traditional patterns we’ve come to know and love may start to break down for elements at the bottom of the table, putting an end to the predictive periodic table as we know it. The reason, Pore explains, is that these heavy nuclei have a very large number of protons. In the actinides (Z > 88), for example, the intense charge of these “extra” protons exerts such a strong pull on the inner electrons that relativistic effects come into play, potentially changing the elements’ chemical properties.
“As some of the electrons are sucked towards the centre of the atom, they shield some of the outer electrons from the pull,” Pore explains. “The effect is expected to be even stronger in the superheavy elements, and this is why they might potentially not be in the right place on the periodic table.”
Understanding the full impact of these relativistic effects is difficult because elements heavier than fermium (Z = 100) need to be produced and studied atom by atom. This means resorting to complex equipment such as accelerated ion beams and the FIONA (For the Identification Of Nuclide A) device at LBNL’s 88-Inch Cyclotron Facility.
The team chose to study Ac and No in part because they represent the extremes of the actinide series. As the first in the series, Ac has no electrons in its 5f shell and is so rare that the crystal structure of an actinium-containing molecule was only determined recently. The chemistry of No, which contains a full complement of 14 electrons in its 5f shell and is the heaviest of the actinides, is even less well known.
In the new work, which is described in Nature, Pore and colleagues produced and directly identified molecular species containing Ac and No ions. To do this, they first had to produce Ac and No. They achieved this by accelerating beams of 48Ca with the 88-Inch Cyclotron and directing them onto targets of 169Tm and 208Pb, respectively. They then used the Berkeley Gas-filled Separator to separate the resulting actinide ions from unreacted beam material and reaction by-products.
The next step was to inject the ions into a chamber in the FIONA spectrometer known as a gas catcher. This chamber was filled with high-purity helium, as well as trace amounts of H2O and N2, at a pressure of approximately 150 torr. After interactions with the helium gas reduced the actinide ions to their 2+ charge state, so-called “coordination compounds” were able to form between the 2+ actinide ions and the H2O and N2 impurities. This compound-formation step took place either in the gas buffer cell itself or as the gas-ion mixture exited the chamber via a 1.3-mm opening and entered a low-pressure (several torr) environment. This transition caused the gas to expand at supersonic speeds, cooling it rapidly and allowing the molecular species to stabilize.
Once the actinide molecules formed, the researchers transferred them to a radio-frequency quadrupole cooler-buncher ion trap. This trap confined the ions for up to 50 ms, during which time they continued to collide with the helium buffer gas, eventually reaching thermal equilibrium. After they had cooled, the molecules were reaccelerated using FIONA’s mass spectrometer and identified according to their mass-to-charge ratio.
FIONA is much faster than previous such instruments and more sensitive. Both properties are important when studying the chemistry of heavy and superheavy elements, which Pore notes are difficult to make, and which decay quickly. “Previous experiments measured the secondary particles made when a molecule with a superheavy element decayed, but they couldn’t identify the exact original chemical species,” she explains. “Most measurements reported a range of possible molecules and were based on assumptions from better-known elements. Our new approach is the first to directly identify the molecules by measuring their masses, removing the need for such assumptions.”
As well as improving our understanding of heavy and superheavy elements, Pore says the new work might also have applications in radioactive isotopes used in medical treatment. For example, the 225Ac isotope shows promise for treating certain metastatic cancers, but it is difficult to make and only available in small quantities, which limits access for clinical trials and treatment. “This means that researchers have had to forgo fundamental chemistry experiments to figure out how to get it into patients,” Pore notes. “But if we could understand such radioactive elements better, we might have an easier time producing the specific molecules needed.”
The post Making molecules with superheavy elements could shake up the periodic table appeared first on Physics World.
President Trump’s recent executive order promoting commercial space competition highlights America’s unique advantage in the final frontier: our dynamic commercial space sector. American companies such as SpaceX, Planet Labs and Sierra Space are rewriting the rules of space access and operations. But as we celebrate these achievements, we must acknowledge a difficult truth: the United States lacks a coherent, […]
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Rocket Lab moved a step closer to the first launch of its Neutron rocket Aug. 28 with the formal opening of the vehicle’s launch site.
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The way in which new materials are designed is changing, with data becoming ever more important in the discovery and design process. Designing soft materials is a particularly tricky task that requires selection of different “building blocks” (monomers in polymeric materials, for example) and optimization of their arrangement in molecular space.
Soft materials also exhibit many complex behaviours that need to be balanced, and their molecular and structural complexities make it difficult for computational methods to help in the design process – often requiring costly trial and error experimental approaches instead. Now, researchers at Hokkaido University in Japan have combined artificial intelligence (AI) with data mining methods to develop an ultra-sticky hydrogel material suitable for very wet environments – a difficult design challenge because the properties that make materials soft don’t usually promote adhesion. They report their findings in Nature.
Hydrogels are a permeable soft material composed of interlinked polymer networks with water held within the network. Hydrogels are highly versatile, with properties controlled by altering the chemical makeup and structure of the material.
Designing hydrogels computationally to perform a specific function is difficult, however, because the polymers used to build the hydrogel network can contain a plethora of chemical functional groups, complicating the discovery of suitable polymers and the structural makeup of the hydrogel. The properties of hydrogels are also influenced by factors including the molecular arrangement and intermolecular interactions between molecules (such as van der Waals forces and hydrogen bonds). There are further challenges for adhesive hydrogels in wet environments, as hydrogels will swell in the presence of water, which needs to be factored into the material design.
To develop a hydrogel with a strong and lasting underwater adhesion, the researchers mined data from the National Center for Biotechnology Information (NCBI) Protein database. This database contains the amino acid sequences responsible for adhesion in underwater biological systems – such as those found in bacteria, viruses, archaea and eukaryotes. The protein sequences were synthetically mimicked and adapted for the polymer strands in hydrogels.
“We were inspired by nature’s adhesive proteins, but we wanted to go beyond mimicking a few examples. By mining the entire protein database, we aimed to systematically explore new design rules and see how far AI could push the boundaries of underwater adhesion,” says co-lead author Hailong Fan.
The researchers used information from the database to initially design and synthesize 180 bioinspired hydrogels, each with a unique polymer network and all of which showed adhesive properties beyond other hydrogels. To improve them further, the team employed machine learning to create hydrogels demonstrating the strongest underwater adhesive properties to date, with instant and repeatable adhesive strengths exceeding 1 MPa – an order-of-magnitude improvement over previous underwater adhesives. In addition, the AI-designed hydrogels were found to be functional across many different surfaces in both fresh and saline water.
“The key achievement is not just creating a record-breaking underwater adhesive hydrogel but demonstrating a new pathway – moving from biomimetic experience to data-driven, AI-guided material design,” says Fan.
The researchers took the three best performing hydrogels and tested them in different wet environments to show that they could maintain their adhesive properties for long time periods. One hydrogel was used to stick a rubber duck to a rock by the sea, which remained in place despite continuous wave impacts over many tide cycles. A second hydrogel was used to patch up a 20 mm hole on a pipe filled with water and instantly stopped a high-pressure leak. This hydrogel remained in place for five months without issue. The third hydrogel was placed under the skin of mice to demonstrate biocompatibility.
The super strong adhesive properties in wet environments could have far ranging applications, from biomedical engineering (prosthetic coatings or wearable biosensors) to deep-sea exploration and marine farming. The researchers also note that this data-driven approach could be adapted for designing other functional soft materials.
When asked about what’s next for this research, Fan says that “our next step is to study the molecular mechanisms behind these adhesives in more depth, and to expand this data-driven design strategy to other soft materials, such as self-healing and biomedical hydrogels”.
The post Super sticky underwater hydrogels designed using data mining and AI appeared first on Physics World.
SAN FRANCISCO – Viridian Space Corp. won a $1.25 million award from the U.S. Air Force for very low Earth orbit (VLEO) electric-propulsion technology. With funding from the Phase II award from Air Force technology innovation arm AFWERX, the Southern California startup will develop an air-fed cathode able to withstand erosion in the oxygen-rich VLEO environment. […]
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SAN FRANCISCO – Nuview, a Florida startup building a constellation of lidar satellites, announced a $5 million award Aug. 28 from the Defense Department’s National Security Innovation Capital (NSIC) program. The funding will allow Orlando-based Nuview to rapidly prototype a lidar (light detection and ranging) payload for a constellation to provide “3D mapping of Earth […]
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