Tuesday, March 18, 2025
Home Blog Page 1484

Researchers enhance efficiency of small electric drives for pumps and fans

0
Researchers enhance efficiency of small electric drives for pumps and fans


Researchers at TU Graz improve small electric drives
Brushless integrated drives have been optimized in terms of efficiency, noise, weight and costs. Credit: Lunghammer—TU Graz

Small electric motors can be found in many household appliances, tools and computers as well as in modern cars, where they drive auxiliary units such as pumps and fans. Individually, each of these motors does not consume much energy, but taken together they offer a great savings potential.

The research team of the recently completed “CD Laboratory for Brushless Drives for Pump and Fan Applications”, headed by Annette Mütze from the Electric Drives and Power Electronic Systems Institute at Graz University of Technology (TU Graz), has now further tapped into this potential. Thanks to innovative design, modified control technology and the use of new manufacturing techniques, the brushless integrated drives developed here consume less energy, operate more quietly and are lighter.

Slanted claws reduce vibrations

Larger claw pole motors are used in vehicle lighting systems, for example. Their use as small drive units is less well known. Mütze’s team has reduced the so-called “cogging torques” of these small drives by skewing and slotting the claws, which does not incur any additional costs. This minimizes the momentary engagement of the claws when the motor is turned, thus reducing unwanted vibrations.

“This enabled us to reduce an important source of noise by 70%. This means that the drives run much more smoothly and quietly,” says Mütze.

Simplified control reduces switching losses

Efficiency gains are achieved through simplified regulation of the current flow. Pulse width modulation usually regulates the current with which the motor of a fan or pump is supplied. In order for the current to flow in the desired rectangular pattern, a large number of switching operations are required, which, however, cause additional energy consumption.

“We only switch our drives on and off once per desired rectangle,” says Mütze. “This enabled us to considerably reduce the additional energy consumption caused by switching losses.”

Particularly at low currents, these drives therefore have a much better overall efficiency than those that are controlled via conventional pulse width modulation. Due to the drastically reduced number of switching operations, the circuit boards of the motors also require half as many capacitors, which reduces costs.

3D printing of ferrite-based material

The third innovation is the implementation of PCB motors with ferrite cores. “PCB” stands for “printed circuit board” and, in the case of motors, means that the windings that generate the magnetic field required for the drive are designed as printed circuit boards. This allows a high degree of automation in production.

Mütze’s team equipped the circuit boards with 3D-printed ferrite cores, which improved the guidance of the magnetic flux in the motors. This was the prerequisite for the use of more cost-effective magnets, which are also based on ferrite.

Citation:
Researchers enhance efficiency of small electric drives for pumps and fans (2024, September 23)
retrieved 23 September 2024
from https://techxplore.com/news/2024-09-efficiency-small-electric-fans.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

Low gravity in space travel found to weaken and disrupt normal rhythm in heart muscle cells

0
Low gravity in space travel found to weaken and disrupt normal rhythm in heart muscle cells


Low gravity in space travel found to weaken and disrupt normal rhythm in heart muscle cells
Heart tissues within one of the launch-ready chambers. Credit: Jonathan Tsui

Johns Hopkins Medicine scientists who arranged for 48 human bioengineered heart tissue samples to spend 30 days at the International Space Station report evidence that the low gravity conditions in space weakened the tissues and disrupted their normal rhythmic beats when compared to Earth-bound samples from the same source.

The scientists said the heart tissues “really don’t fare well in space,” and over time, the tissues aboard the space station beat about half as strongly as tissues from the same source kept on Earth.

The findings, they say, expand scientists’ knowledge of low gravity’s potential effects on astronauts’ survival and health during long space missions, and they may serve as models for studying heart muscle aging and therapeutics on Earth.

A report of the scientists’ analysis of the tissues is published in the Proceedings of the National Academy of Sciences.

Previous studies showed that some astronauts return to Earth from outer space with age-related conditions, including reduced heart muscle function and arrythmias (irregular heartbeats), and that some—but not all—effects dissipate over time after their return.

But scientists have sought ways to study such effects at a cellular and molecular level in a bid to find ways to keep astronauts safe during long spaceflights, says Deok-Ho Kim, Ph.D., a professor of biomedical engineering and medicine at the Johns Hopkins University School of Medicine. Kim led the project to send heart tissue to the space station.

To create the cardiac payload, scientist Jonathan Tsui, Ph.D. coaxed human induced pluripotent stem cells (iPSCs) to develop into heart muscle cells (cardiomyocytes). Tsui, who was a Ph.D. student in Kim’s lab at the University of Washington, accompanied Kim as a postdoctoral fellow when Kim moved to Johns Hopkins University in 2019. They continued the space biology research at Johns Hopkins.

Tsui then placed the tissues in a bioengineered, miniaturized tissue chip that strings the tissues between two posts to collect data about how the tissues beat (contract). The cells’ 3D housing was designed to mimic the environment of an adult human heart in a chamber half the size of a cell phone.

To get the tissues aboard the SpaceX CRS-20 mission, which launched in March 2020 bound for the space station, Tsui says he had to hand-carry the tissue chambers on a plane to Florida, and continue caring for the tissues for a month at the Kennedy Space Center. Tsui is now a scientist at Tenaya Therapeutics, a company focused on heart disease prevention and treatment.

Once the tissues were on the space station, the scientists received real-time data for 10 seconds every 30 minutes about the cells’ strength of contraction, known as twitch forces, and on any irregular beating patterns. Astronaut Jessica Meir, Ph.D., M.S. changed the liquid nutrients surrounding the tissues once each week and preserved tissues at specific intervals for later gene readout and imaging analyses.

The research team kept a set of cardiac tissues developed the same way on Earth, housed in the same type of chamber, for comparison with the tissues in space.

When the tissue chambers returned to Earth, Tsui continued to maintain and collect data from the tissues.

“An incredible amount of cutting-edge technology in the areas of stem cell and tissue engineering, biosensors and bioelectronics, and microfabrication went into ensuring the viability of these tissues in space,” says Kim, whose team developed the tissue chip for this project and subsequent ones.

Devin Mair, Ph.D., a former Ph.D. student in Kim’s lab and now a postdoctoral fellow at Johns Hopkins, then analyzed the tissues’ ability to contract.

In addition to losing strength, the heart muscle tissues in space developed irregular beating (arrhythmias)—disruptions that can cause a human heart to fail. Normally, the time between one beat of cardiac tissue and the next is about a second. This measure, in the tissues aboard the space station, grew to be nearly five times longer than those on Earth, although the time between beats returned nearly to normal when the tissues returned to Earth.

The scientists also found, in the tissues that went to space, that sarcomeres—the protein bundles in muscle cells that help them contract—became shorter and more disordered, a hallmark of human heart disease.

In addition, energy-producing mitochondria in the space-bound cells grew larger, rounder and lost the characteristic folds that help the cells use and produce energy.

Finally, Mair, Eun Hyun Ahn, Ph.D.—an assistant research professor of biomedical engineering—and Zhipeng Dong, a Johns Hopkins Ph.D. student, studied the gene readout in the tissues housed in space and on Earth. The tissues at the space station showed increased gene production involved in inflammation and oxidative damage, also hallmarks of heart disease.

“Many of these markers of oxidative damage and inflammation are consistently demonstrated in post-flight checks of astronauts,” says Mair.

Kim’s lab sent a second batch of 3D engineered heart tissues to the space station in 2023 to screen for drugs that may protect the cells from the effects of low gravity. This study is ongoing, and according to the scientists, these same drugs may help people maintain heart function as they get older.

The scientists are continuing to improve their “tissue on a chip” system and are studying the effects of radiation on heart tissues at the NASA Space Radiation Laboratory. The space station is in low Earth orbit, where the planet’s magnetic field shields occupants from most of the effects of space radiation.

More information:
Kim, Deok-Ho, Spaceflight-induced contractile and mitochondrial dysfunction in an automated heart-on-a-chip platform, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2404644121. doi.org/10.1073/pnas.2404644121

Citation:
Low gravity in space travel found to weaken and disrupt normal rhythm in heart muscle cells (2024, September 23)
retrieved 23 September 2024
from https://phys.org/news/2024-09-gravity-space-weaken-disrupt-rhythm.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

Swedish battery maker Northvolt to slash 1,600 jobs, quarter of staff

0
Swedish battery maker Northvolt to slash 1,600 jobs, quarter of staff


Northvolt Ett factory in Skelleftea will see 1,000 jobs cut as part of cost savings plan by the Swedish company
Northvolt Ett factory in Skelleftea will see 1,000 jobs cut as part of cost savings plan by the Swedish company.

Sweden’s beleaguered electric car battery maker Northvolt said Monday it would cut a quarter of its staff in the country, as it struggles with strained finances and a slowdown in demand.

The loss of 1,600 jobs in Sweden comes as electric car sales slump in Europe and the continent lags far behind China in battery production.

“While overall momentum for electrification remains strong, we need to make sure that we take the right actions at the right time in response to headwinds in the automotive market, and wider industrial climate,” Northvolt CEO Peter Carlsson said in a statement.

He added that Northvolt needed to “focus all energy and investments into our core business.”

Northvolt, which warned on September 9 that cuts were coming, said that following “initial steps” of a strategic review it estimated that proposed cost-saving measures would result in about 1,000 redundancies at its primary Skelleftea plant—where an expansion project would be suspended.

The company had intended to expand the capacity of the facility to provide an annual output of 30 GWh, but will now focus on ramping up to 16 GWh.

In July, it said it hoped to reach an annual production of over one GWh this year—still far from the facility’s capacity.

One GWh is enough to equip 20,000 average sized cars.

“Success in the ramp-up of production at Northvolt Ett is critical for delivering to our customers and enabling sustainable business operations,” Carlsson said in a statement.

Another 400 positions would be cut in the city of Vasteras and 200 in the Swedish capital Stockholm.

“The rescoping of operations is critical to ensure a sustainable operation and cost base,” Northvolt said.

It added that “to achieve this a workforce reduction of approximately 20 percent at a global level, and 25 percent in Sweden is required.”

Cornerstone

The company employs 6,500 people, according to its website.

Northvolt has been seen as a cornerstone of European attempts to catch up with China and the United States in the production of battery cells, a crucial component of lower-emission cars.

Europe accounts for just three percent of global battery cell production, but has set its sights on 25 percent of the market by the end of the decade.

But the battery maker has also been plagued by production delays, which in May led BMW to drop an order worth 2 billion euros ($2.2 billion).

Northvolt still reports to have contracts worth $55 billion with customers such as Scania, Volvo and Volkswagen.

Volkswagen is also Northvolt’s largest shareholder, with a 21 percent stake.

Production delays and lower demand from automotive customers have led to a rapidly deteriorating financial situation, which accelerated at the end of the summer, according to the business daily Dagens Industri.

According to Swedish media reports, Northvolt is trying to organize a new share issue to raise 7.5 billion kronor.

The battery maker has also faced scrutiny in Sweden over concerns about work safety at its sites, with Swedish police currently investigating a number of unexplained deaths of factory workers, who died after working at the plant in Skelleftea.

In mid-September, Swedish Prime Minister Ulf Kristersson said that “there are no plans for the Swedish state to become a part owner of Northvolt or anything like that”.

Since its creation, the Swedish company has secured $15 billion of credit and capital.

© 2024 AFP

Citation:
Swedish battery maker Northvolt to slash 1,600 jobs, quarter of staff (2024, September 23)
retrieved 23 September 2024
from https://techxplore.com/news/2024-09-swedish-battery-maker-northvolt-slash.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

Study of four crane species reveals complicated relationships between birds and their environments

0
Study of four crane species reveals complicated relationships between birds and their environments


How cranes navigate their complex world
An adult white-naped crane affixed with unique color bands to identify the individual in Mongolia. Credit: Wildlife Science and Conservation Center (WSCC) of Mongolia

Knowing how animals use their environments to survive and thrive is a key challenge for predicting how global climate change will affect wildlife. A global collaborative study of four species of crane has shed light on the way that migrations are finely tuned to unpredictable and complex environments.

A team from 10 countries combined novel animal tracking technology, remote-sensed information about the environment, and a new statistical framework to gain insight into four iconic species: common cranes, white-naped cranes, black-necked cranes, and demoiselle cranes.

The study, led by scientists from the Max Planck Institute of Animal Behavior and Yale University, was published in Proceedings of the National Academy of Sciences on September 23.

The researchers used tiny GPS tracking devices to follow the movements of 104 cranes in Africa, Asia, and Europe. These devices included unique solar-powered GPS leg bands developed by scientists from MPI-AB. The tracking data revealed the impressive migrations that cranes undertook.

Some of the migratory routes exceeded 6,400 km of travel round trip and required crossing barriers such as the Alps or Himalaya mountain ranges, the deserts of the Arabian peninsula, or the Mediterranean Sea.

In addition to the tracking study, the researchers also developed a statistical framework that revealed how the cranes’ movements relate to aspects of the environment, such as the presence of crops or water bodies nearby, and the temperature and vegetation cover on the land.

“Animals have to satisfy their own needs with what they can get from their environment, but both of these are changing constantly,” says Scott Yanco, first author on the study and a postdoctoral researcher at the University of Michigan.

“This creates an intriguing optimization problem that we wanted to know if cranes were solving through long-distance migration.”

The researchers found that all four crane species experienced starkly different environmental conditions over a year, and that these periods were synchronized with important events in their lives. This was particularly pronounced when comparing temperatures or resource availability on wintering and summer breeding grounds.

For some, the migrations themselves entailed huge shifts in environmental conditions. For example, the demoiselle cranes migrated across the Tibetan plateau and had to contend with massive fluctuations in temperature while doing so.

“We suspect this all has to do with different biological needs during these different times of the year,” adds Yanco, who did the research when he was at the Yale Center for Biodiversity and Global Change. For example, common cranes clearly emphasized agricultural areas during the late summer, a period that aligns with raising juveniles and preparing for fall migration.

“This is exactly when we would expect them to want easy access to food,” he says.

For other species, access to food may come at a cost. The black-necked cranes in the study had to decide between safe roosting habitat and abundant resources.

“Amazingly, the balance between these competing needs changed over the year depending on what the birds were doing,” adds Yanco. During migration they opted for safer roosting conditions, whereas during breeding they leaned towards abundant food.

“This type of shifting emphasis depending on what cranes need at any given time is what we were expecting to see,” says Ivan Pokrovsky, a postdoctoral researcher at MPI-AB and last author on the study.

“But we were blown away by how well the cranes used movement to resolve trade-offs among competing needs and to access certain environments during key periods of the year.”

Understanding how animals interact with their surroundings not only gives us a more nuanced view of how they survive in complex environments—it is crucial for developing policy and management actions to address the dual crises of climate change and biodiversity loss, the authors say.

The study’s framework offers a statistical tool for understanding the complicated relationships between animals and their environments that can be widely applied to conservation and management efforts of wildlife.

“When we know how animals use certain environmental conditions, we can make better predictions about how species might respond to human-caused global change and develop more effective interventions that ensure we preserve the conditions species need to survive,” says Pokrovsky.

More information:
Scott W. Yanco et al, Migratory birds modulate niche tradeoffs in rhythm with seasons and life history, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2316827121

Provided by
Max Planck Society


Citation:
Study of four crane species reveals complicated relationships between birds and their environments (2024, September 23)
retrieved 23 September 2024
from https://phys.org/news/2024-09-crane-species-reveals-complicated-relationships.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

New origami-inspired system turns flat-pack tubes into strong building materials

0
New origami-inspired system turns flat-pack tubes into strong building materials


New origami-inspired system turns flat-pack tubes into strong building materials
Dr. Jeff Lee with a new flat-pack tube designed by the RMIT team. Credit: Will Wright, RMIT University

Engineers at RMIT University have designed an innovative tubular structural system that can be packed flat for easier transport and pop up into strong building materials. This breakthrough is made possible by a self-locking system inspired by curved-crease origami—a technique that uses curved crease lines in paper folding.

Lead researchers Dr. Jeff (Ting-Uei) Lee and Distinguished Professor Mike (Yi Min) Xie, said that bamboo, which has internal structures providing natural reinforcement, inspired the tube design.

“This self-locking system is the result of an intelligent geometric design,” said Lee, from RMIT’s School of Engineering. “Our invention is suitable for large-scale use—a panel, weighing just 1.3 kg, made from multiple tubes can easily support a 75 kg person.”

Flat-pack tubes are already widely used in engineering and scientific applications, such as in biomedical devices, aerospace structures, robotics and civil construction, including pop-up buildings as part of disaster recovery efforts.

The new system makes these tubes quicker and easier to assemble, with the capability to automatically transform into a strong, self-locked state.

The research is published in Proceedings of the National Academy of Sciences. Other contributors to this work include Drs Hongjia Lu, Jiaming Ma and Ngoc San Ha from RMIT’s School of Engineering and Associate Professor Joseph Gattas from the University of Queensland.






New origami-inspired system turns flat-pack tube into strong building material. Credit: Will Wright, RMIT University

“Our research not only opens up new possibilities for innovative and multifunctional structural designs, but it can also significantly improve existing deployable systems,” said Xie, from the School of Engineering.

“When NASA deploys solar arrays, for example, the booms used are tubes that were packed flat before being unfurled in space,” Lee said. “These tubes are hollow, though, so they could potentially deform under certain forces in space. With our new design, these booms could be a stronger structure.”

Xie explained that their smart algorithm enabled control over how the structure behaved under forces by changing the tube orientations.

“With our origami-inspired innovation, flat-pack tubes are not only easy to transport, but they also become strong enough to withstand external forces when in use,” Xie said. “The tube is also self-locking, meaning its strong shape is securely locked in place without the need for extra mechanisms or human intervention.”






The team’s invention is suitable for large-scale use—a panel, weighing just 1.3 kg, made from multiple tubes can easily support a 75 kg person. Credit: RMIT University

Next steps

The team will continue to improve the design and explore new possibilities for its development.

“We aim to extend the self-locking feature to different tube shapes and test how the tubes perform under various forces, such as bending and twisting,” Lee said. “We are also exploring new materials and manufacturing methods to create smaller, more precise tubes.”

The team is developing tubes that can deploy themselves for a range of applications without needing much manual effort.

“We plan to improve our smart algorithm to make the tubes even more adaptable and efficient for different real-world situations,” Xie said.

More information:
Xie, Yi Min et al, Self-locking and stiffening deployable tubular structures, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2409062121. doi.org/10.1073/pnas.2409062121

Provided by
RMIT University


Citation:
New origami-inspired system turns flat-pack tubes into strong building materials (2024, September 23)
retrieved 23 September 2024
from https://techxplore.com/news/2024-09-origami-flat-tubes-strong-materials.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link