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05/19/2016 : 149986
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Nanocellulose Combined with Red Onion Dye Offers Efficient UV Shielding for Solar Cells.
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Posted by Okachinepa on 03/21/2025 @
Courtesy of SynEvol
Credit: University of Turku
Scientists from the University of Turku in Finland studied the use of bio-based materials to create efficient UV protection films for solar panels. The research, released in ACS Applied Optical Materials, was the inaugural investigation to examine how the characteristics of various bio-based UV filters evolve over time.
Solar cells are vulnerable to degradation caused by UV exposure and are typically safeguarded against this by films derived from petroleum, like those composed of polyvinyl fluoride (PVF) and polyethylene terephthalate (PET).
Investigations in materials engineering aim to discover substitutes for oil-derived plastics using bio-based materials, one example being nanocellulose. Nanocellulose is produced by reducing cellulose into nanoscale fibers, which can subsequently be processed in various methods to achieve UV protection.
A recent study conducted by the University of Turku and Aalto University in Finland, along with Wageningen University in the Netherlands, discovered that nanocellulose infused with red onion skin extract offers highly effective UV protection. The nanocellulose film shielded 99.9% of UV radiation up to 400 nanometers. This UV filter surpassed the commercial PET-based UV filter that was chosen for the study as a benchmark for market standards.
"Films made of nanocellulose that have been dyed with red onion present a promising alternative for uses where the protective material needs to be bio-based," states Doctoral Researcher Rustem Nizamov from the University of Turku.
The research analyzed the strength and characteristics of four varieties of protective films derived from cellulose nanofibers. The nanocellulose films were individually treated with red onion extract, lignin, and iron ions, each of which has demonstrated effective UV-blocking properties in prior studies. The film infused with the red onion extract demonstrated the highest effectiveness in blocking UV radiation.
Courtesy of SynEvol
Credit: University of Turku
UV radiation (under 400 nm) can damage solar cells; however, the passage of visible light and some infrared light too (especially from 700 to 1,200 nm) is crucial, since solar cells convert this radiation into electricity.
Creating bio-based materials frequently requires balancing UV protection with light transmission in the visible spectrum. For example, lignin, a natural polymer recognized for its UV-absorbing characteristics, has a deep brown hue that restricts its application in transparent films.
The film dyed with red onion demonstrated to be an intriguing solution, achieving over 80% light transmission at longer wavelengths (650–1,100 nanometers). The movie also upheld its performance during the extended trial phase.
The filters' resilience and efficiency were evaluated under artificial lighting for 1,000 hours, roughly corresponding to a year's worth of sunlight in the open air within a central European climate. Digital photography was used to observe visual changes in the solar cells and filter materials.
The research highlighted the necessity of extended testing for UV filters, since the UV protection and light transmittance of other bio-based filters varied considerably as time passed. “For instance, the films applied with iron ions exhibited strong initial transmittance that diminished after aging,” states Nizamov.
The UV filter films were evaluated on dye-sensitized solar cells, as these cells are especially prone to damage caused by UV radiation.
"According to Nizamov, these findings are significant for the UV protection of various solar cell types, such as perovskite and organic photovoltaics, along with any application where employing a bio-based UV filter is essential."
In the future, the goal of the researchers is to create biodegradable types of solar cells that can serve as energy sources for sensors, such as those used in food packaging.
The timber industry aims to create new premium products. "In electronics, these could also serve as components for solar cells," states Kati Miettunen, a Professor in Materials Engineering.
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Researchers Examine the Hidden Expenses of Netflix's Autoplay Feature.
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Posted by Okachinepa on 03/21/2025 @
Courtesy of SynEvol
Credit: Department of Computer Science at University of Chicago
Autoplay, a function that starts the subsequent episode or film without user interaction, has become a standard feature of contemporary streaming services such as Netflix. However, what is the actual price of this convenience regarding our control over time and decision-making?
A recent study conducted by researchers at the University of Chicago's Department of Computer Science, which expands on earlier research, highlights the unforeseen effects of autoplay functions, showing how this seemingly harmless feature might discreetly affect user habits and consumption trends.
The study, published on the arXiv preprint server and slated for presentation at the Conference on Computer-Supported Cooperative Work and Computing later this year, investigates the consequences of disabling autoplay on Netflix and the wider ramifications for user independence. The research provides intriguing perspectives on how this element could be altering our connection with streaming services.
"Services such as Netflix aim to reduce friction, ensuring that chances for users to stray from the activity they are passively involved in are limited," stated lead author and fifth-year Ph.D. candidate Brennan Schaffner. "The 5-second autoplay timer offers barely sufficient time for viewers to reflect on, or even reconsider, their initial reasons for using the platform."
The research involved 76 participants who had already indicated moderate to heavy use of Netflix. Half of the participants disabled autoplay, whereas the control group kept it enabled. The researchers examined the viewing habits of both groups throughout the study duration, along with the six months leading up to it.
The research revealed that disabling autoplay resulted in participants watching significantly less time on Netflix. Participants who disabled Netflix's autoplay spent more time between episodes, giving them the opportunity to contemplate their viewing choices and consider the content they were watching with greater awareness.
The reduction in viewing session duration—approximately 18 minutes per Netflix session—can probably be attributed to the heightened "friction" required to keep watching content, which promotes more deliberate choices regarding when to cease viewing.
A participant mentioned, "It made me aware of how many episodes I was viewing... I hadn't focused on it as much previously." Now I thought, "Oh right, I need to do this three times, so this is the third episode."
Although autoplay is heavily promoted as a user-friendly function that keeps viewers engaged with their preferred content, this study highlights the possible drawbacks. The function eliminates barriers, allowing Netflix viewers to continue watching seamlessly. Nonetheless, the authors of the study noted that this ease of use could have drawbacks—users might lose track of time, watch more content than planned, and unintentionally engage in harmful behaviors like interrupted sleep or other unhealthy viewing habits.
Earlier studies have indicated that autoplay could serve as a type of "dark pattern" design, discreetly influencing users' focus to favor participation on the platform instead of user welfare.
"The term 'dark patterns' describes a group of interconnected digital design strategies that impair a user's capacity to make choices that favor their own interests," Schaffner clarified. "They are often referred to as 'platform tactics' that steer users towards choices they might not normally make."
Once autoplay was disabled, participants in the study were requested to consider their experience and if they might reactivate the feature. The outcomes were varied: Approximately half of the participants noted they would reactivate autoplay for its practicality, claiming that it would be simpler than having to rise and actively interact with the platform to access the next content they desired. A participant mentioned, "I appreciate that it automatically plays the next episode, so I can remain in my cozy bed."
Conversely, around one-third of participants indicated that they intended to maintain autoplay disabled after realizing the extra time they had to consider if they wished to continue viewing or not.
The results highlight the necessity for streaming services such as Netflix to reconsider the incorporation of autoplay within their user interfaces. By providing finer controls over autoplay options, such as disabling this feature by default or giving users a selection during account setup, platforms can enable users to manage convenience alongside independence, resulting in a more personalized experience.
For instance, future enhancements could involve allowing users to determine how many episodes should be queued for autoplay before asking for their input or providing extended countdown periods prior to automatically starting the subsequent episode.
These design modifications are crucial—particularly for children—due to the wider ethical and regulatory consequences related to autoplay functionalities. As platforms focus more on user engagement, the possibility of autoplay affecting decision-making and compromising autonomy brings forth significant worries.
As regulatory oversight intensifies, particularly from entities like the Federal Trade Commission (FTC) and the European Union's General Data Protection Regulation (GDPR), there is an increasing acknowledgment of the necessity to safeguard users against features that could influence their actions.
This involves analyzing how autoplay and comparable design features affect user wellness and independence—particularly regarding children's access to content that could promote harmful usage, considering that automatically playing content might not have been deliberately selected by the child or their guardians.
"This research is among the initial efforts to distinguish and evaluate the influence of a specific attention-capture dark pattern—namely, autoplay—and its effects on viewing habits," stated Assoc. Prof. Marshini Chetty, the primary author of this study.
"We require additional research of this nature that offers measurable indicators of online manipulation to assist regulators, platform creators, and researchers in improving consumer safeguards and to guarantee that designs do not produce adverse effects on society."
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Eco-Friendly Hydrogen Powered Boats Is The Newest In The Autonomous Realm
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Posted by Okachinepa on 03/21/2025 @
Courtesy of SynEvol
Credit: Communications Engineering (2025)
Freight transportation contributes significantly to a large carbon footprint. From 2010 to 2018, the transportation industry produced roughly 14% of worldwide greenhouse gas emissions. To tackle this issue, specialists are seeking alternative, eco-friendly options—not just for road transport, but also for shipping, a field where powering cargo vessels with batteries has been particularly challenging.
A promising yet insufficiently explored solution includes small, self-sufficient, hydrogen-fueled vessels that could somewhat substitute for long-distance trucking. A study published in Communications Engineering has now investigated this missing link by a research team headed by business chemist Prof Stephan von Delft from the University of Münster.
For the first time, the team has created a mathematical model of this type of boat and conducted a life cycle and cost analysis. "Our analysis indicates the situations where hydrogen-powered boats are not only more environmentally friendly but also more cost-effective than traditional transport options," explains von Delft. "As a result, they hold significance for policymakers and the industry."
Utilizing their mathematical model, the researchers determined the emissions and total expenses for each kilometer traveled. They distinguished between inexpensive "gray" hydrogen, created from fossil fuels through steam reforming, and the low-emission yet pricier "green" hydrogen, generated from renewable energy sources through water electrolysis. They contrasted these findings with the overall expenses of diesel-, hydrogen-, and battery-operated trucks.
The findings indicate that vessels fueled by green hydrogen have lower operating costs than diesel trucks for distances greater than 576 km and more affordable than battery- or hydrogen-fueled trucks for routes exceeding 624 km. Thus, this type of vessel may represent the most economical option for moving cargo over distances exceeding 624 km.
Projected across the whole road transport sector, self-driving, hydrogen-fueled vessels could seize 18% of the market (around. 350 billion ton kilometers) in a more cost-efficient manner than trucking.
Courtesy of SynEvol
Credit: Communications Engineering (2025)
The examined vessels can carry precisely one standard container. This indicates that they are unable to substitute container vessels on the open ocean. Nonetheless, doctoral student Simon Schlehuber notes that they offer an intriguing option for inland transportation, particularly in comparison to trucks, which also carry precisely one container.
Moreover, the vessels could enlarge the navigable river system because of their shallow draft and uphold shipping activities, particularly during periods of low water. "According to Schlehuber, the latter represents a significant benefit in the context of climate change."
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Scientist Found New Alternatives To Create Nuclear Fusion Fuel
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Posted by Okachinepa on 03/21/2025 @
Courtesy of SynEvol
Credit: Harris Kohl & Andrew Ezazi
Lithium-6 is crucial for creating nuclear fusion fuel; however, separating it from the far more prevalent isotope, lithium-7, often necessitates liquid mercury, which is highly toxic. Currently, scientists have created a mercury-free approach to extract lithium-6 that matches the efficiency of the traditional technique. The journal Chem features the introduction of the new method.
"This represents progress in overcoming a significant hurdle for nuclear energy," states chemist and lead author Sarbajit Banerjee from ETH Zürich and Texas A&M University. "Lithium-6 is essential for the revival of nuclear energy, and this technique may offer a practical solution for isotope separation."
The traditional technique for extracting lithium-6, known as the COLEX process, uses liquid mercury and has been prohibited in the United States since 1963 over environmental worries.
Since that time, nearly all lithium-6 utilized in US research has depended on a dwindling supply held at Oak Ridge National Laboratory in Tennessee. Establishing a secure technique for isolating lithium-6 will be essential to enabling nuclear fusion as a viable energy source.
The researchers discovered their technique for isolating lithium-6 while working on membranes for purifying "produced water"—groundwater extracted during oil and gas drilling that needs treatment before being reinjected underground. They observed that their cleaning membrane collected unequal amounts of lithium from the water.
"We noticed that we could extract lithium with high selectivity since there was significantly more salt than lithium in the water," Banerjee states. "This prompted us to consider if this material could also exhibit some selectivity for the 6-lithium isotope."
The lithium-binding characteristics of the membrane arise from a substance known as zeta-vanadium oxide (ζ-V2O5), an inorganic compound synthesized in a laboratory that features a one-dimensional tunnel framework.
"Zeta-V2O5 exhibits remarkable characteristics—it's an outstanding battery material, and we're now discovering that it can selectively capture lithium, even showing isotopic selectivity," Banerjee explains.
"According to co-first author Andrew Ezazi from Texas A&M, Lithium-6 ions adhere much more robustly to the tunnels, which explains the selectivity mechanism." "Visualize the connections between V2O5 and lithium like a spring; lithium-7, being heavier, is more inclined to break that connection, while lithium-6, being lighter, vibrates less and forms a stronger bond."
When lithium ions are incorporated into the zeta-V2O5, the material slowly shifts in color from vibrant yellow to deep olive green, allowing for easy observation of the lithium incorporation level.
The team demonstrates that one electrochemical cycle increased lithium-6 concentration by 5.7%. To achieve fusion-grade lithium, needing at least 30% lithium-6, the procedure must be repeated 25 times, and approximately 90% lithium-6 can be acquired in around 45 consecutive cycles.
"This degree of enrichment is highly competitive with the COLEX process, minus the mercury," states Ezazi.
"Certainly, we're not engaged in industrial production at this stage, and there are several engineering challenges to address regarding the design of the flow loop, but over a series of flow cycles, fusion-grade lithium can be obtained quite inexpensively," Banerjee states.
The researchers state that their findings imply that materials such as zeta-V2O5 might be utilized to isolate various substances, for instance, to differentiate between radioactive and non-radioactive isotopes.
Currently, the team is working to elevate their approach to an industrial scale.
"I believe there is significant interest in nuclear fusion as the definitive answer for clean energy," states Banerjee. "We are seeking assistance to turn this into a viable solution."
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Researchers Create 3D-Printed Innovations for Particle Detection
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Posted by Okachinepa on 03/19/2025 @
Courtesy of SynEvol
Credit: Tim Weber
In 2024, the T2K Collaboration started gathering fresh neutrino data following the enhancement of its experiment with state-of-the-art detectors. One of these, the SuperFGD, is an extremely sensitive two-ton detector composed of almost two million tiny cubes. Every cube is made from plastic scintillator (PS), a substance that produces light when charged particles move through it.
Although neutrinos are uncharged, they can sometimes engage with other particles, creating electrons, protons, muons, or pions – detectable signals. Every PS cube includes three optical fibers oriented in various directions, which collect the emitted light and direct it to 56,000 photodetectors. This configuration generates a three-dimensional (3D) representation of particle trajectories, assisting scientists in understanding neutrino behavior more thoroughly.
Improving detectors of this kind is essential for the progress of particle physics, but it also prompts a significant question: Is there a more effective method to construct large-scale detectors? Building a device using two million separate cubes, one layer at a time, is a massive undertaking. Could high-energy physics experiments gain from a more effective method?
These obstacles propel the investigations of Professors Davide Sgalaberna and André Rubbia at the Institute for Particle Physics and Astrophysics. Together with researchers from ETH Zurich, CERN, HES-SO, HEIG-VD, COMATEC-AddiPole, and the Institute for Scintillation Materials in Ukraine, they have recently released a study in Communications Engineering. Their study presents a completely 3D-printed plastic scintillator detector designed for elementary particles. This project is a component of the 3D printed DETector (3DET) Collaboration, directed by Sgalaberna with technical oversight by Dr. Umut Kose. The group views their discovery as a significant advancement for quicker, more economical manufacturing of large-scale particle detectors, setting the stage for future progress in neutrino research.
PS detectors enable the tracking of paths and the measurement of energy loss of charged particles traversing the scintillator material with a quick temporal response. These traits have influenced their increasing success since they were introduced in the 1950s. In a PS, fluorescent materials known as fluors are embedded within a solid polymer matrix. A charged particle traveling through the material energizes the polymer matrix: a non-radiative dipole-dipole interaction transfers the excitation energy to the fluorescents, which then de-excite by emitting near-ultraviolet light in a matter of nanoseconds. A different kind of fluor is frequently incorporated into the polymer to alter the wavelength of the emitted light and prevent absorption in the scintillator substance. Optical fibers gather the light generated by a PS by altering its wavelength to the green segment of the visible spectrum, allowing for the capture of the emitted light and enhancing its attenuation length.
To achieve the best tracking of elementary particles, granular 3D scintillating detectors have been constructed from numerous smaller volumes, like the PS cubes found in SuperFGD. In this situation, it’s essential that the smaller units are optically separated to monitor various charged particles independently. The 3DET Collaboration is knowledgeable about these constructed detectors: Sgalaberna originated SuperFGD and directed its creation and assembly as part of the T2K Collaboration. Just as the 2D display of a laptop or smartphone consists of individual glowing pixels, a granular 3D particle detector can be seen as an assembly of scintillating voxels. Every voxel needs to collaborate to produce high-quality data: while each voxel is separate, it contributes to a larger entity.
"It's fundamentally an engineering issue," states lead author Tim Weber regarding the experiment described in the article. Educated as a mechanical engineer at ETH Zurich, Weber became a member of the Exotic Matter and Neutrino Physics group in the Department of Physics and the 3DET Collaboration three years back, contributing his varied expertise in additive manufacturing (AM), or 3D printing. He prefers to adopt a pragmatic perspective on the issue: if the aim is to construct increasingly larger particle detectors with superb tracking resolution, then the production time and costs need to be minimized. This necessitates solutions that ensure rapid production while maintaining the quality and performance of the particle detector.
The perfect production system can assemble numerous dazzling voxels into a solid block. The 3DET Collaboration and others have previously collaborated with AM on PS detector prototypes; some initial challenges they faced – particularly regarding detector performance – underscored two key decision points: material selection and the kind of AM processes employed to manufacture the detector. For instance, AM usually struggles to manage various materials while obtaining the material transparency required so that the scintillation light isn't reabsorbed by the PS. Furthermore, not every AM process is capable of creating hollow shapes. The latter problem frequently results in subtractive methods—such as creating holes in the voxels for wavelength-shifting fibers—that complicate the automation of the manufacturing process.
Weber, Sgalaberna, and their team realized they required a completely tailored AM setup. Their innovative manufacturing technique, known as fused injection modelling (FIM), combines two established methods: fused deposition modelling (FDM) and injection molding. The AM fabrication process involves three steps: initially, a 5 × 5 layer of the reflective optical frame is created, serving as the mold for the PS, which consists of 25 empty cubes that are open at the top and coated in white, produced using FDM, with holes for the optical fibers, and without support structures. In this case, the selected polymer filament for the frame is forced through a nozzle in a procedure referred to as extrusion. When this 5 × 5 mold is prepared, metal rods are placed into the holes to make room for the fibers. Next, the FDM extrusion system is substituted with a long nozzle that injects scintillation substance into the mold, progressing from bottom to top in each vacant cube and permitting the molten material to disperse as uniformly as possible. In the third step, a heated punch is utilized to create a flat top surface prepared for the subsequent 5 × 5 matrix layer.
By adhering to this process, the team created what they call a SuperCube, a detector featuring 125 optically isolated voxels, organized in a 5 × 5 × 5 layout with total dimensions of 59 mm (width and length) by 57.2 mm (height), where every voxel is read out using two orthogonal wavelength-shifting fibers. The production duration for a single voxel was estimated to be approximately 6 minutes; this duration is anticipated to decrease as the manufacturing process becomes more automated due to a newly developed 3D printing system.
The researchers evaluated their prototype's performance using cosmic-particle data, concentrating on the single-cube scintillation light yield obtained and the crosstalk occurring between voxels. They evaluated the SuperCube against a similar detection system made with cast polymerization, a traditional manufacturing method, and observed no notable difference in performance. The crosstalk, reliant on the optical isolation of each voxel, seems to be marginally greater with FIM but remains at a few-percent level, which is suitable for 3D particle tracking. "This marks the first instance where a 3D printed scintillator detector can identify charged particles, including those from cosmic rays and CERN's test beams, and accurately reconstruct their tracks and energy loss," states Sgalaberna.
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