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3D Printing Industry

Scientists 3D print gunpowder substitute, achieve 420m/s bullet velocity

Researchers from the Xi’an Modern Chemistry Research Institute in China have 3D printed a functional gun propellant using SLA technology. The gunpowder-esque substance is a carefully constructed blend of photopolymer resin, RDX (a high explosive), and other reactive additives. Initial gun testing of the 3D printed propellant has garnered some promising results, as the scientists […]

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Author: Kubi Sertoglu

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Spintronics: Faster data processing through ultrashort electric pulses

Physicists at Martin Luther University Halle-Wittenberg (MLU) and Lanzhou University in China developed a simple concept that could improve significantly magnetic-based data processing. Using ultrashort electric pulses in the terahertz range, data can be written, read and erased very quickly. This would make data processing faster, more compact and energy efficient. The researchers confirmed their theory by running complex simulations and the results were published in the journal NPG Asia Materials.

Magnetic data storage is indispensable for storing securely the huge amount of data generated every day, for instance through social networks. Once stored, the information can still be retrieved after many years. Charge-based data storage used for example in mobile phones is much more short-lived when there is no energy supply. Traditional magnetic hard drives and components have disadvantages of their own, due to the moving mechanical parts and the need for magnetic fields which makes them more power consuming and relatively slow when reading and writing data.

“We were after a fast and energy-efficient alternative,” explains Professor Jamal Berakdar from the Institute of Physics at MLU. He and his colleagues from Lanzhou University came up with a simple idea. By using ultrashort pulses in the terahertz range, information could be written in magnetic nano-vortices and retrieved within picoseconds. Theoretically, this renders possible billions of read and write operations per second without the need for magnetic fields. “With the appropriately shaped pulses the data can be processed very quickly at low energy cost,” says Berakdar. The new concept is based on existing terahertz and magnetism technologies. “It exploits advances in electric pulse generation and nanomagnetism.”

So far, the method has been tested in computer simulations. “In recent years there have been fantastic advances in generating and controlling electrical pulses,” says Berakdar. Therefore, it makes sense to explore new ways to apply these pulses to data storage. The concept presented by the researchers offers a simple tool for controlling magnetic nano-vortices and can therefore be directly utilised for new storage technologies.

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Researchers from the University of Colorado Denver develop new 3D printing material that mimics biological tissues

Researchers from the University of Colorado Denver and the Southern University of Science and Technology in China, have created a novel 3D printing material that’s able to imitate the behaviours of biological tissues. Using the Digital Light Processing (DLP) 3D printing process, the research team developed a honey-like Liquid Crystal Elastomer (LCE) resin. When hit […]

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Author: Paul Hanaphy

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Researchers determine 3D printing more effective in treating hip fractures

A group of researchers from China and the U.S. have used 3D printing to create 1:1 scale pelvic models of hip fracture patients, to aid in the surgical treatment of both-column acetabular fractures. In the study, the researchers compare traditional methods of contouring plates intra-operatively with the use of pre-contoured plates according to physical 3D […]

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Author: Anas Essop

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Exploring the impacts of climate change on hydropower production

A new study by researchers from IIASA and China investigated the impacts of different levels of global warming on hydropower potential and found that this type of electricity generation benefits more from a 1.5°C than a 2°C climate scenario.

In a sustainable and less carbon-intensive future, hydropower will play an increasingly crucial role as an important source of renewable and clean energy in the world’s overall energy supply. In fact, hydropower generation has doubled over the last three decades and is projected to double again from the present level by 2050. Global warming is however threatening the world’s water supplies, posing a significant threat to hydropower generation, which is a problem in light of the continuous increase in energy demand due to global population growth and socioeconomic development.

The study, undertaken by researchers from IIASA in collaboration with colleagues at several Chinese institutions and published in the journal Water Resources Research, employed a coupled hydrological and techno-economic model framework to identify optimal locations for hydropower plants under global warming levels of 1.5°C and 2°C, while also considering gross hydropower potential, power consumption, and economic factors. According to the authors, while determining the effects of different levels of global warming has become a hot topic in water resources research, there are still relatively few studies on the impacts of different global warming levels on hydropower potential.

The researchers specifically looked at the potential for hydropower production under the two different levels of warming in Sumatra, one of the Sunda Islands of western Indonesia. Sumatra was chosen as it is vulnerable to global warming because of sea level rise, and the island’s environmental conditions make it an ideal location for developing and utilizing hydropower resources. They also modeled and visualized optimal locations of hydropower plants using the IIASA BeWhere model, and discussed hydropower production based on selected hydropower plants and the reduction in carbon emissions that would result from using hydropower instead of fossil fuels.

The results show that global warming levels of both 1.5°C and 2°C will have a positive impact on the hydropower production of Sumatra relative to the historical period. The ratio of hydropower production to power demand provided by 1.5°C of global warming is however greater than that provided by 2°C of global warming under a scenario that assumes stabilization without overshooting the target after 2100. This is due to a decrease in precipitation and the fact that the south east of Indonesia observes the highest discharge decrease under this scenario. In addition, the reduction in CO2 emissions under global warming of 1.5°C is greater than that achieved under global warming of 2°C, which reveals that global warming decreases the benefits necessary to relieve global warming levels. The findings also illustrate the tension between greenhouse gas-related goals and ecosystem conservation-related goals by considering the trade-off between the protected areas and hydropower plant expansion.

“Our study could significantly contribute to establishing a basis for decision making on energy security under 1.5°C and 2°C global warming scenarios. Our findings can also potentially be an important basis for a large range of follow-up studies to, for instance, investigate the trade-off between forest conservancy and hydropower development, to contribute to the achievement of countries’ Nationally Determined Contributions under the Paris Agreement,” concludes study lead author Ying Meng, who started work on this project as a participant of the 2018 IIASA Young Scientists Summer Program (YSSP). She is currently affiliated with the School of Environment at the Harbin Institute of Technology in China.

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China celebrates its first set of 3D printing tests in space

China has successfully completed its first 3D printing tests in the microgravity of space. A “space 3D printer”, developed by the China Academy of Space Technology (CAST), alongside a 3D printed CubeSat deployer, was launched on Tuesday the 5th of May on China’s new large carrier rocket – the Long March-5B. A few minutes after […]

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Author: Kubi Sertoglu

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Zhejiang researchers develop modular 4D printed assembly

Researchers in China have presented a study on a modular method of 4D printing that aims to overcome the geometrical limitations of the process.  The advantage of 4D printing, based on a digitally controlled 2D-to-3D transformation, is that it forgoes the layer-by-layer fabrication process of 3D printing, resulting in a faster production method. However, the […]

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Author: Anas Essop

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Researchers from China use 3D printing to reinforce bulk metal glass composites with metal frame

Researchers from China have developed a promising route for the fabrication of strong-and-tough metallic BMG composites, using a combination of ultrasonic vibration-assisted thermoplastic forming and 3D printing. Bulk metallic glasses (BMGs) are a unique class of materials that possess an amorphous atomic-level structure and a variety of desirable mechanical, chemical, and physical properties. However, the […]

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Author: Anas Essop

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Stable perovskite LEDs one step closer

Researchers at Linköping University, working with colleagues in Great Britain, China and the Czech Republic, have developed a perovskite light-emitting diode (LED) with both high efficiency and long operational stability. The result has been published in Nature Communications.

“Light-emitting diodes based on perovskites are still not sufficiently stable for practical use, but we have brought them one step closer,” says Professor Feng Gao, and head of research at the Division of Biomolecular and Organic Electronics, Linköping University.

Perovskites are a large family of semiconducting materials that have aroused the interest of scientists around the world. Their special crystal structure means that they have excellent optical and electronic properties, while they are both easy and cheap to manufacture. Most progress has been made in research into the use of perovskites in solar cells, but they are also well-suited for the manufacture of LEDs.

The efficiency of the LEDs, which measures the fraction of charge carriers input to the material that are subsequently emitted as light, has increased considerably in recent years, and will soon reach that of competing technology. They are, however, not particularly stable, which means that so far they cannot be used in practice.

“Much remains to be done. Until now, most of the perovskite LEDs have either low efficiency or poor device stability,” says Xiao-Ke LiU, research fellow in the Division of Biomolecular and Organic Electronics. He and Feng Gao are the principal authors of the article.

Many research groups have worked on this dilemma, without particular success. Now, researchers at LiU, working with colleagues in Great Britain, China and the Czech Republic, have found a way forward. They have used a perovskite that consists of lead, iodine and an organic substance, formamidinium. They have then embedded the perovskite into an organic molecule matrix to form a composite thin film.

“This molecule with two amino groups at its ends helps the other substances to form a high quality crystal structure that is characteristic for perovskites, and makes the crystal stable,” says Heyong Wang, doctoral student in the Division of Biomolecular and Organic Electronics.

The new composite thin film has enabled the research group to develop LEDs with an efficiency of 17.3% with a long half-lifetime, approximately 100 hours.

Perovskites that contain lead and a halogen, in this case iodine, have the best light-emitting properties.

“We would very much like to get rid of the lead. So far we haven’t found a good way to do this, but we are working hard on it, says Feng Gao.

The next steps are to test new combinations of different perovskites and organic molecules and to understand in detail how the nucleation and crystallisation processes occur. Different perovskites give light at different wavelengths, which is a requirement for the long-term goal of obtaining white light LEDs.

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Simple, solar-powered water desalination

A completely passive solar-powered desalination system developed by researchers at MIT and in China could provide more than 1.5 gallons of fresh drinking water per hour for every square meter of solar collecting area. Such systems could potentially serve off-grid arid coastal areas to provide an efficient, low-cost water source.

The system uses multiple layers of flat solar evaporators and condensers, lined up in a vertical array and topped with transparent aerogel insulation. It is described in a paper appearing today in the journal Energy and Environmental Science, authored by MIT doctoral students Lenan Zhang and Lin Zhao, postdoc Zhenyuan Xu, professor of mechanical engineering and department head Evelyn Wang, and eight others at MIT and at Shanghai Jiao Tong University in China.

The key to the system’s efficiency lies in the way it uses each of the multiple stages to desalinate the water. At each stage, heat released by the previous stage is harnessed instead of wasted. In this way, the team’s demonstration device can achieve an overall efficiency of 385 percent in converting the energy of sunlight into the energy of water evaporation.

The device is essentially a multilayer solar still, with a set of evaporating and condensing components like those used to distill liquor. It uses flat panels to absorb heat and then transfer that heat to a layer of water so that it begins to evaporate. The vapor then condenses on the next panel. That water gets collected, while the heat from the vapor condensation gets passed to the next layer.

Whenever vapor condenses on a surface, it releases heat; in typical condenser systems, that heat is simply lost to the environment. But in this multilayer evaporator the released heat flows to the next evaporating layer, recycling the solar heat and boosting the overall efficiency.

“When you condense water, you release energy as heat,” Wang says. “If you have more than one stage, you can take advantage of that heat.”

Adding more layers increases the conversion efficiency for producing potable water, but each layer also adds cost and bulk to the system. The team settled on a 10-stage system for their proof-of-concept device, which was tested on an MIT building rooftop. The system delivered pure water that exceeded city drinking water standards, at a rate of 5.78 liters per square meter (about 1.52 gallons per 11 square feet) of solar collecting area. This is more than two times as much as the record amount previously produced by any such passive solar-powered desalination system, Wang says.

Theoretically, with more desalination stages and further optimization, such systems could reach overall efficiency levels as high as 700 or 800 percent, Zhang says.

Unlike some desalination systems, there is no accumulation of salt or concentrated brines to be disposed of. In a free-floating configuration, any salt that accumulates during the day would simply be carried back out at night through the wicking material and back into the seawater, according to the researchers.

Their demonstration unit was built mostly from inexpensive, readily available materials such as a commercial black solar absorber and paper towels for a capillary wick to carry the water into contact with the solar absorber. In most other attempts to make passive solar desalination systems, the solar absorber material and the wicking material have been a single component, which requires specialized and expensive materials, Wang says. “We’ve been able to decouple these two.”

The most expensive component of the prototype is a layer of transparent aerogel used as an insulator at the top of the stack, but the team suggests other less expensive insulators could be used as an alternative. (The aerogel itself is made from dirt-cheap silica but requires specialized drying equipment for its manufacture.)

Wang emphasizes that the team’s key contribution is a framework for understanding how to optimize such multistage passive systems, which they call thermally localized multistage desalination. The formulas they developed could likely be applied to a variety of materials and device architectures, allowing for further optimization of systems based on different scales of operation or local conditions and materials.

One possible configuration would be floating panels on a body of saltwater such as an impoundment pond. These could constantly and passively deliver fresh water through pipes to the shore, as long as the sun shines each day. Other systems could be designed to serve a single household, perhaps using a flat panel on a large shallow tank of seawater that is pumped or carried in. The team estimates that a system with a roughly 1-square-meter solar collecting area could meet the daily drinking water needs of one person. In production, they think a system built to serve the needs of a family might be built for around $100.

The researchers plan further experiments to continue to optimize the choice of materials and configurations, and to test the durability of the system under realistic conditions. They also will work on translating the design of their lab-scale device into a something that would be suitable for use by consumers. The hope is that it could ultimately play a role in alleviating water scarcity in parts of the developing world where reliable electricity is scarce but seawater and sunlight are abundant.

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