The researchers, led by the University of Cambridge, used spacecraft laser-altimeter measurements of the shape of the upper surface of the ice cap to identify subtle patterns in its height. They then showed that these patterns match computer model predictions for how a body of water beneath the ice cap would affect the surface.

Their results agree with earlier ice-penetrating radar measurements that were originally interpreted to show a potential area of liquid water beneath the ice. There has been debate over the liquid water interpretation from the radar data alone, with some studies suggesting the radar signal is not due to liquid water.

The results, reported in the journal Nature Astronomy, provide the first independent line of evidence, using data other than radar, that there is liquid water beneath Mars’ south polar ice cap.

“The combination of the new topographic evidence, our computer model results, and the radar data make it much more likely that at least one area of subglacial liquid water exists on Mars today, and that Mars must still be geothermally active in order to keep the water beneath the ice cap liquid,” said Professor Neil Arnold from Cambridge’s Scott Polar Research Institute, who led the research.

Like Earth, Mars has thick water ice caps at both poles, roughly equivalent in combined volume to the Greenland Ice Sheet. Unlike Earth’s ice sheets however, which are underlain by water-filled channels and even large subglacial lakes, the polar ice caps on Mars have until recently been thought to be frozen solid all the way to their beds due to the cold Martian climate.

In 2018, evidence from the European Space Agency’s Mars Express satellite challenged this assumption. The satellite has an ice-penetrating radar called MARSIS, which can see through Mars’ southern ice cap. It revealed an area at the base of the ice that strongly reflected the radar signal, which was interpreted as an area of liquid water beneath the ice cap.

However, subsequent studies suggested that other types of dry materials, which exist elsewhere on Mars, could produce similar patterns of reflectance if they exist beneath the ice cap. Given the cold climate conditions, liquid water beneath the ice cap would require an additional heat source, such as geothermal heat from within the planet, at levels above those expected for present-day Mars. This left confirmation of the existence of this lake awaiting another, independent line of evidence.

On Earth, subglacial lakes affect the shape of the overlying ice sheet — its surface topography. The water in subglacial lakes lowers friction between the ice sheet and its bed, affecting the velocity of ice flow under gravity. This in turn affects the shape of the ice sheet surface above the lake, often creating a depression in the ice surface followed by a raised area further down-flow.

The team — which also included researchers from the University of Sheffield, the University of Nantes, University College, Dublin, and the Open University — used a range of techniques to examine data from NASA’s Mars Global Surveyor satellite of the surface topography of the part of Mars’ south polar ice cap where the radar signal was identified.

Their analysis revealed a 10-15 kilometre-long surface undulation comprising a depression and a corresponding raised area, both of which deviate from the surrounding ice surface by several metres. This is similar in scale to undulations over subglacial lakes here on Earth.

The team then tested whether the observed undulation on the surface of the ice could be explained by liquid water at the bed. They ran computer model simulations of ice flow, adapted to specific conditions on Mars. They then inserted a patch of reduced bed friction in the simulated ice sheet bed where water, if present, would allow the ice to slide and speed up. They also varied the amount of geothermal heat coming from inside the planet. These experiments generated undulations on the simulated ice surface that were similar in size and shape to those the team observed on the real ice cap surface.

The similarity between the model-produced topographic undulation and the actual spacecraft observations, together with the earlier ice-penetrating radar evidence suggest that there is an accumulation of liquid water beneath Mars’ south polar ice cap, and that magmatic activity occurred relatively recently in the subsurface of Mars to enable the enhanced geothermal heating needed to keep the water in a liquid state.

“The quality of data coming back from Mars, from orbital satellites as well as from the landers, is such that we can use it answer really difficult questions about conditions on, and even under the planet’s surface, using the same techniques we also use on Earth,” said Arnold. “It’s exciting to use these techniques to find out things about planets other than our own.”

The research was supported in part by the European Research Council.

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Materials provided by University of Cambridge. Original written by Sarah Collins. The text in this work is licensed under a Creative Commons Attribution 4.0 International License Note: Content may be edited for style and length.

“There is much noise about the direct effects of agrochemicals on pollinators, a subject of profound societal attention, but it now emerges that ozone is a silent threat to pollinators and thus pollination,” says lead author Evgenios Agathokleous, an ecologist at Nanjing University of Information Science & Technology. “These impacts of ozone have long been missed.”

Ozone gas can be both friend and foe to the planet. In the stratosphere, 12 kilometers above sea level, ozone forms naturally and helps protect the Earth from harmful sun rays. But below that zone, ozone is a damaging pollutant. Tropospheric-level ozone gas is created by a photochemical reaction between volatile organic compounds — emitted by vegetation and commonly found in substances such as paint and aerosols — and oxides of nitrogen, which are released when fossil fuels burn. Tropospheric ozone levels have been rising because a warming climate is creating optimal conditions for its formation.

“Ozone pollution can affect the timing and duration of flowering in such a way that the occurrence of flowering is asynchronous to the activities of pollinators,” says Agathokleous. “It can also change the color of flowers, disrupting the visual signals to pollinators. Ozone pollution can also directly react with pollen, decreasing its quality, but also indirectly changing the amount of pollen.”

Ozone pollution can also damage plant leaves almost instantly, leaving injury signs of diverse colors and shapes and discoloring leaves. When damaged, leaves have a hard time photosynthesizing and struggle to provide the plant with the energy it needs to grow. Plants emit their own organic volatile compounds that act as chemical signals facilitating communication from one plant to another and alert pollinators to the presence of a waiting flower. Ozone pollution appears to be disrupting these chemical signatures.

“Changes in the composition of the volatile blends could also have severe implications to pollinators because they might not recognize host plants and their qualities in the same way they did in the past,” says Agathokleous. “Within plant tissues, ozone pollution could decrease the amount of nutrients that are essential to insects, increase the abundance of chemicals that are harmful to insects ingesting them, and degrade the overall quality of plant tissues.”

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The breakthrough could be a potential game-changer for manufacturing customized chip-based microelectromechanical systems (MEMS). These mini-machines are mass-produced in large volumes for hundreds of electronic products, including smartphones and cars, where they provide positioning accuracy. But for more specialized manufacturing of sensors in smaller volumes, such as accelerometers for aircraft and vibration sensors for industrial machinery, MEMS technologies demand costly customization.

Frank Niklaus, who led the research at KTH Royal Institute of Technology in Stockholm, says the new 3D printing technique, which was published in Nature Microsystems & Nanoengineering, provides a way to get around the limitations of conventional MEMS manufacturing.

“The costs of manufacturing process development and device design optimizations do not scale down for lower production volumes,” he says. The result is engineers are faced with a choice of suboptimal off-the-shelf MEMS devices or economically unviable start-up costs.

Other low-volume products that could benefit from the technique include motion and vibration control units for robots and industrial tools, as well as wind turbines.

The researchers built on a process called two-photon polymerization, which can produce high resolution objects as small as few hundreds of nanometers in size, but not capable of sensing functionality. To form the transducing elements, the method uses a technique called shadow-masking, which works something like a stencil. On the 3D-printed structure they fabricate features with a T-shaped cross-section, which work like umbrellas. They then deposit metal from above, and as a result, the sides of the T-shaped features are not coated with the metal. This means the metal on the top of the T is electrically isolated from the rest of the structure.

With this method, he says it takes only few hours to manufacture a dozen or so custom designed MEMS accelerometers using relatively inexpensive commercial manufacturing tools. The method can be used for prototyping MEMS devices and manufacturing small- and medium-sized batches of tens of thousands to a few thousand MEMS sensors per year in an economically viable way, he says.

“This is something that has not been possible until now, because the start-up costs for manufacturing a MEMS product using conventional semiconductor technology are on the order of hundreds of thousands of dollars and the lead times are several months or more,” he says. “The new capabilities offered by 3D-printed MEMS could result in a new paradigm in MEMS and sensor manufacturing.

“Scalability isn’t just an advantage in MEMS production, it’s a necessity. This method would enable fabrication of many kinds of new, customized devices.”

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Materials provided by KTH, Royal Institute of Technology. Original written by David Callahan. Note: Content may be edited for style and length.

This is why research teams from TU Wien and the Fritz Haber Institute in Berlin have developed a novel approach that allows to have “triple eyes” on a catalytic reaction — using three different surface microscopies. This way, they were able to show that during the catalytic conversion of hydrogen and oxygen to water, reaction fronts on the crystal surface not only form remarkable geometric patterns, but also a new mechanism of the propagation of these fronts was discovered. Especially for climate-relevant technologies such as ecologically clean hydrogen-based energy production, a comprehensive understanding of such processes is crucial.

Different measurements in a single instrument

“Many scientific questions can only be answered by combining different microscopy methods on the same sample, which is called correlative microscopy,” says Prof. Günther Rupprechter from the Institute of Materials Chemistry at TU Wien. “However, this usually comes with limitations.” You have to remove a sample from one instrument and perform the same experiment again in another microscope. Often, for methodological reasons, the experimental conditions are then completely different — some measurements take place in a vacuum, others in air. Often temperatures are different. In addition, you may not be looking at the same spot on the sample with different instruments — this can also influence the results. Thus, it is difficult to combine the results of different measurements in a reliable way.

Ultraviolet, X-rays and electrons

Now, however, it has been possible to combine three different microscopies in a way that the same spot on the same sample was examined under the same environmental conditions. Three different electron microscopies were used: two different variants of photoemission electron microscopy (PEEM), namely UV-PEEM and X-PEEM, and low energy electron microscopy (LEEM).

In UV-PEEM and X-PEEM, the sample surface is illuminated with ultraviolet light and X-rays, respectively. In both cases, it results in electrons being emitted from the surface. Similar to how light beams are focused in an optical microscope, the electron beams form a real-time image of the surface and of the processes taking place there. In an X-PEEM, one can additionally filter the emitted electrons according to their energies and thereby determine the chemical composition of the sample surface. Access to the necessary high-energy, high-intensity X-rays was provided to the research team by the Berlin synchrotron (HZB BESSY II). In the LEEM technique, the surface is irradiated with an electron beam. The electrons that are backscattered from the surface create the real time image of the sample surface and of the ongoing processes, such as a catalytic reaction.

Since all three microscopies use different imaging mechanisms, this allowed to study different aspects of catalytic hydrogen oxidation on a structurally identical site of the sample , says Prof. Yuri Suchorski, who has been involved in surface microscopy since 1974. “In addition, the X-PEEM technique provides chemical contrast and therefore allows us to correlate the pattern formation on the surface with the chemical composition of the surface and the reactants present on the surface, hence the term correlative microscopy.”

Watching how hydrogen oxidizes to water

Thus, it became possible to study the oxidation of hydrogen on structurally well-defined microscopic regions of a rhodium foil (structure determination by researchers at USTEM of TU Wien) in a versatile way and in real time.

The reaction spreads over the surface like a wave, revealing a new kind of pattern formation that had never been encountered before. “In front of the spreading reaction front, new small islands of catalytically active areas form, accelerating the propagation of the reaction,” says Prof. Rupprechter. In computer simulations that provide virtual reaction microscopy, the team was able to model and explain the formation of these islands.

Through the correlative approach, it was now possible to effectively use the specific strength of each of the respective microscopy methods (spatial and energy resolution, field of view, magnification down to the nanometer range), and thus to image an ongoing catalytic reaction in unprecedented detail.

The oxidation of hydrogen to water by solid catalysts is one of the significant processes that enable energy generation without combustion and without pollution (the exhaust gas consists of pure water), e.g., in fuel cells. For future developments of new green energy production technologies, it will be important to watch ongoing catalytic reactions at work with several eyes in order to deeply understand fine details of the catalytic processes.

With EV sales soaring worldwide, potential buyers are not just weighing up the price tag, but also the logistics and expense of charging the planet-friendly cars.

UniSA engineers have calculated that EV owners can reduce annual electricity costs by almost 40 per cent if households are not totally reliant on the grid and they charge at home during off-peak periods.

In a new paper published in Renewable Energy, Professor Mahfuz Aziz and colleagues address EV owners’ concerns about charging costs, one of the main obstacles in opting for an environmentally-friendly vehicle.

“Electric vehicles will become an important component of household energy consumption globally under plans to replace petrol-fuelled cars within the next decade,” Prof Aziz says.

“For motorists with private car spaces, home charging is the most convenient option, but for those still totally reliant on the electricity grid for their energy, the costs could mount significantly.”

Record-low prices for rooftop photovoltaic (PV) systems and declining battery costs are encouraging households to ‘go green,’ but consumers need to factor in multiple variables, researchers say.

Using data from South Australia, where over 40 per cent of homes have rooftop solar panels, the researchers compared several household scenarios, considering EV charging demand, PV solar panel installation cost, battery degradation and export power limits.

Based on typical household energy consumption (17 kW/day in SA) and motorists’ average daily travel distance (36.7km in AU), researchers analysed annual energy costs for households with petrol-based cars and those with EVs. They also analysed energy consumption during peak periods, between 5pm-9pm.

“In a basic case, all energy is imported from the grid where there are no solar panels, batteries or electric vehicles,” Prof Aziz says.

“When solar panels are added, about 20 per cent less energy is imported and with batteries this is reduced by around 83 per cent. When electric vehicles are added, consumed energy rises significantly but imported energy can be reduced by around 89 per cent of total consumption.

“Our results demonstrate that households with petrol-based cars can reduce their annual energy costs by 6.71 per cent using solar panels, and by 10.38 per cent with the addition of a battery system. Replacing petrol-based cars with electric vehicles can reduce annual energy costs by 24 per cent and 32 per cent respectively. The most significant reduction (39.6 per cent) can be achieved with off-peak charging.”

The research team includes PhD student Ms Yan Wu and co-supervisor Dr Mohammed Haque. The team is currently investigating cost effective EV charging strategies for larger groups such as residential communities and university campuses while minimising impact on the power grid and distribution feeders.

The popularity of electric vehicles is rapidly increasing across the globe, according to drive.com and it’s estimated that by 2030 there will be 145 million EVs on the road — compared to 11 million today. Despite the pandemic, electric vehicle sales increased globally by 43 per cent in 2020, although only made up 0.7 per cent of all car sales in Australia.

By 2030, however, at least 50 per cent of all new cars sales in NSW are expected to be electric and other states are anticipated to follow this trend.

Teachers’ turnover intentions, burnout symptoms and poor experienced teacher-working environment fit are interlinked, and therefore also likely to occur simultaneously. If a teacher experiences one of the above, the risk of experiencing others increases, too.

The researchers explored experienced burnout and teacher-working environment fit and compared teacher cohorts with or without persistent turnover intentions. The data included 1,064 Finnish basic education teachers (working in grades 1-9, teaching pupils aged 7-16), of whom 344 (32%) reported persistent turnover intentions in a five-year follow-up.

The tendency to experience work-related exhaustion, cynicism and feelings of inadequacy in the teaching profession proved rather permanent. According to the researchers, it seems that more work experience does not protect against the risk of burnout; instead, teachers experience their workload relatively similarly regardless of how long their career is.

“Some teachers seem to feel that they have very little opportunity to influence their workload, and they are mainly just trying to cope with the factors contributing to it. Workload management skills can therefore play an important role in promoting teachers’ coping,” says Doctoral Researcher, lead author Katariina Räsänen of the University of Eastern Finland.

Burnout symptoms are associated with having few positive experiences

Support provided by the professional community is an important factor in preventing the development of burnout.

“Positive experiences in the workplace, received recognition and a constructive and enabling work climate seem to protect against cynicism towards, and alienation from, the professional community,” says Räsänen, who herself also works as a lecturer.

According to Räsänen, getting professional recognition is, rather surprisingly, more likely in the early stages of the teaching career.

“Opportunities to get professional encouragement, support and recognition, which are needed by everyone, mostly seem to coincide with the early stages of the teaching career.”

Influencing one’s own work plays an important role

The teacher-working environment fit is affected by several individual and work-related factors. The study indicates that school size plays a role in teachers’ perceived well-being at work.

“Smaller schools often have a constructive and enabling work climate that also provides support for the teacher-working environment fit,” Räsänen says.

According to the results, teachers with leadership tasks had a lower risk of burnout than teachers who did not have an opportunity to influence their work through such tasks. Teachers with leadership tasks also experienced less feelings of inadequacy and had a better experienced teacher-work environment fit. The difference may be explained by better possibilities to influence one’s own work.

“This interesting observation shows how teachers’ autonomy, or a lack thereof, is also associated with the development of burnout. It seems that fostering teachers’ autonomy continues to be a key factor in promoting their well-being at work.”

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Materials provided by University of Eastern Finland. Note: Content may be edited for style and length.