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Feb 24, 2024

Electrocatalytic Mechanism of Water Splitting by Ultralow Content of RuO2-supported on Fluorine-Doped Graphene Using a Constant Potential Method

Posted by in categories: chemistry, computing

RuO2 has been established as the benchmark catalyst for the oxygen evolution reaction (OER). However, the low precious metal content compared to other OER industrial catalysts like RuO2, Pt/C, and IrO2 makes a hybrid heterosurface of RuO2 and F-doped graphene (RuO2@FGr) an excellent catalyst with a high current density. Moreover, the advantage of graphene support increases stability. We investigated the mechanism of the OER on RuO2@FGr using density functional theory (DFT) and the computational hydrogen electrode model (CHEM). In CHEM, the adsorption energy of the reactive intermediates is considered for the reduction potential calculation. This is followed by free energy calculation and, eventually, overpotential calculation using standard or reversible hydrogen electrodes (SHE/RHE). Computational OER activity calculated in the gas phase using density functional theory (DFT) cannot explain the contribution of the condensed phase, water organization energy, the kinetics of the elementary steps, and electrochemical contribution. The current study will address the issue by implementing an implicit solvation model and the electrostatic contribution by considering the charge extrapolation model. We used molecular RuO2 to mimic the exact experimental weight percentage. Fluorine intercalation doping improves the binding of oxygen-based intermediate species to the reactive surface due to a shift in the d-band center toward the Fermi level. The graphene sheet behaves as a conductor after fluorine doping, and the electron density contribution near the Fermi level is clearly distinguished from the projected density of states (PDOS). Using the implicit solvation model with altered parameters, we find improvements in the reaction barrier for hydroperoxo formation. An overpotential of 0.40 V vs RHE is obtained for the cavity shape parameter and charge density cutoff parameter of 0.8 and 0.0035 Å–3. For completion, we implement the constant potential model (CPM) to extrapolate our results calculated at the nonzero potential environment to 0.0 V potential. The mean energy path computed using the climbing image nudged elastic band provides the activation and reaction energy, and the values are extrapolated to 0.0 V RHE using the CPM correction. Implementing both thermochemical and electrochemical corrections simultaneously, we can find a reasonable overpotential of the studied catalytic reaction.

Feb 24, 2024

Solar-Powered Toilet Treats and Recycles Wastewater

Posted by in categories: chemistry, mobile phones, solar power, sustainability

The Seva Sustainable Sanitation innovation is a smart, electro-chemical toilet unit, which is suitable for use in off-grid rural areas of developing countries. It can turn toilet wastewater into disinfected water, using the power from its mounted solar panels to sterilise and clarify it. Macronutrients such as carbon, nitrogen, and phosphorus can be nearly fully recovered from the waste, leaving nothing but water that is recycled for flushing or irrigation. The toilet unit is also equipped with sensors, a mobile phone-based maintenance guide, and smart grid technology that empowers anyone in the community to repair the system when necessary. When a toilet is out of order, the technology automatically directs users to other nearby sanitation systems. So far, the solution has been deployed in four countries.

Feb 24, 2024

Recycling fertilizers from human excreta exhibit high nitrogen fertilizer value and result in low uptake of pharmaceutical compounds

Posted by in categories: climatology, economics, sustainability

Year 2023 face_with_colon_three


Recycling nutrients is essential for closing nutrient loops within a circular economy. Using locally available resources such as human excreta to produce bio-based recycling fertilizers can substitute mineral fertilizers and thereby promote environmentally friendly food production. To better understand the fertilizer potential and nitrogen value of human excreta, three novel and safe recycling products were evaluated in a field experiment. Two nitrified urine fertilizers (NUFs) and one fecal compost were applied alone or in combination, and compared against the commercial organic fertilizer vinasse. In addition, the uptake of pharmaceuticals was assessed for treatments with compost application. White cabbage (Brassica oleracea var. capitata f. alba) was cultivated in plots in three different soil types (sand, loam or silt) treated with the fertilizers according to plant needs and mineral soil nitrogen content. The two NUFs resulted in marketable yields similar to those of vinasse in all soil types. Combining fecal compost with a NUF led to increased marketable yield compared to compost alone. The highest yield was recorded from the sandy soil, where vinasse and NUF treatments led to comparable yields, as expected in organic productions systems (up to 72 t ha−1). The cabbage yield and total aboveground fresh biomass followed the following trend in all soils: NUFs ∼ vinasse ≥ compost + NUF ≥ compost. Nitrogen uptake in the cabbage heads and total biomass was significantly higher in sand (69.5–144 kg ha−1) than loam (71.4–95.8 kg ha−1). All compost treatments alleviated the effect of soil type and resulted in comparable nitrogen uptake and yield in all soil types. Plant uptake of pharmaceuticals (Carbamazepin) was higher in sand than in loam, and concentration in the edible part was lower than in the outer leaves. In conclusion, NUF alone appears to be a promising successful fertilizer substitute in horticultural food production. The combined application of NUF and compost led to slightly lower crop yields, but may increase soil carbon content in the long term, promoting climate-friendly food production.

In view of a growing world population and the human alteration of nutrient cycles, including nitrogen (N) and phosphorus ℗ (Rockström et al., 2009), transforming food production is a major challenge of this century (Springmann et al., 2018). Both N and P are essential nutrients for healthy plant growth in crop production; however, their addition to synthetic fertilizers is currently organized in a linear economy. The Haber-Bosch process, used to generate plant-available N from its airborne unreactive form, is energy intensive, depending on fossil fuels such as natural gas, and associated with high greenhouse gas emissions (Wang et al., 2021). P is obtained from finite, depleting phosphate rock resources and its mining is increasingly more expensive and polluting (Desmidt et al., 2015). This background emphasize the need for significant improvements of nutrient management in agriculture and for alternative, circular N and P sources to achieve global food security (Gerten et al.

Feb 24, 2024

NASA Rover Spots Dead Mars Helicopter in Its “Final Resting Place”

Posted by in category: space

NASA’s Mars helicopter, Ingenuity, has seen its last days of flight — but its friend, the Perseverance rover, hasn’t said goodbye just yet.

Originally published earlier this month by NASA, the grainy raw images of Ingenuity sitting sadly in the sand ripples of Mars’ Neretva Vallis river valley, cleaned up images of the little chopper that could were posted by German design student Simeon Schmauss on on X-formerly-Twitter and Flickr.

The enhanced displays, as Schmauss explained, were created when he pasted together six of the raw images, zoomed in on Ingenuity, and altered the image’s colors “to approximately match what the human eye would see.”

Feb 24, 2024

Nonequilibrium solvent response force: What happens if you push a Brownian particle

Posted by in categories: information science, particle physics

Forces cannot simply be added to the Langevin equation. Momentum transfer from the Brownian particle on the solvent always produces an additional nonequilibrium solvent response force that has highly nontrivial statistical properties.

Feb 24, 2024

Pharmacies nationwide face delays as health-care tech company reports cyberattack

Posted by in categories: cybercrime/malcode, health

A leading health-care technology company is experiencing a network outage due to a “cyber security issue,” pausing prescription services at pharmacies nationwide.

Feb 24, 2024

A new phase of matter: Physicists achieve first demonstration of non-Abelian anyons in a quantum processor

Posted by in categories: particle physics, quantum physics

Our physical, 3D world consists of just two types of particles: bosons, which include light and the famous Higgs boson; and fermions—the protons, neutrons, and electrons that comprise all the “stuff,” present company included.

Theoretical physicists like Ashvin Vishwanath, Harvard’s George Vasmer Leverett Professor of Physics, don’t like to limit themselves to just our world, though. In a 2D setting, for instance, all kinds of new particles and states of matter would become possible.

Vishwanath’s team used a powerful machine called a to make, for the first time, a brand-new phase of matter called non-Abelian topological order. Previously recognized in theory only, the team demonstrated synthesis and control of exotic particles called non-Abelian anyons, which are neither bosons nor fermions, but something in between.

Feb 24, 2024

Science fiction books that predicted the future with terrifying accuracy

Posted by in categories: biotech/medical, innovation

Science fiction writers have anticipated a variety of modern inventions, from cars to organ transplants. Some books barely seem like fiction.

Feb 24, 2024

Next Generation Neural Interfaces: Research on Emerging Technologies at Imperial College London

Posted by in categories: biotech/medical, health, neuroscience

The era of bioelectronic healthcare is dawning upon us. As electronic systems shrink in size and improve in functionality, we see more and more emerging devices that can track vital signs, such as heart rate and blood pressure, realising the grand vision of highly connected sensor nodes monitoring patients’ health beyond the hospital doors. The real revolution in digital healthcare, however, lies in bringing not only the diagnostics but also the therapy to the patient which requires interfacing the world of electronics with biology.

Interfacing the nervous system provides an immense opportunity to observe (through recording) and modify (through stimulation) the functional state of the biological system to fundamentally understand various diseases and health conditions, and to ultimately develop suitable therapies through closed-loop systems [1]. Consequently, a host of neural interface modalities, with varying levels of invasiveness, have been developed over the past decades. Among all, interfacing at the individual neuron level allows the highest level of information transfer from the brain.

Despite the success of devices such as Cochlear Implants, interfacing at the individual neuron level is still severely limited due to challenges such as selectivity (for stimulation) and thermal-limitations imposed on data transmission to prevent neural tissue damage. The latter is a major bottleneck in improving information transfer rate of neural recording systems as they scale up. Hence, there is currently a tremendous drive to develop new enabling technologies for neuroscience to provide insightful views on how motor or sensory information is represented and transformed by the brain, as well as revealing how this complex system is affected by neurological injuries and disease.

Feb 24, 2024

(PDF) Universe as a partially computable information-processing system

Posted by in category: futurism

PDF | Universe as a partially computable information-processing system | Find, read and cite all the research you need on ResearchGate.