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Jul 27, 2023

Researchers demonstrate scaling of aligned carbon nanotube transistors to below sub-10 nm nodes

Posted by in categories: computing, nanotechnology, particle physics

Carbon nanotubes, large cylindrical molecules composed of hybridized carbon atoms arranged in a hexagonal structure, recently attracted significant attention among electronics engineers. Due to their geometric configuration and advantageous electronic properties, these unique molecules could be used to create smaller field-effect transistors (FETs) that exhibit high energy efficiencies.

FETs based on carbon nanotubes have the potential to outperform smaller transistors based on silicon, yet their advantage in real-world implementations has yet to be conclusively demonstrated. A recent paper by researchers at Peking University and other institutes in China, published in Nature Electronics, outlines the realization of FETs based on carbon nanotubes that can be scaled to the same size of a 10 nm silicon technology node.

“Recent progress in achieving wafer-scale high density semiconducting carbon nanotube arrays brough us one step closer to the practical use of carbon nanotubes in CMOS circuits,” Zhiyong Zhang, one of the researchers who carried out the study, told Phys.org. “However, previous research efforts have mainly focused on the scaling of channel or gate length of carbon nanotube transistors while keeping large contact dimensions, which cannot be accepted for high density CMOS circuits in practical applications.

Jul 27, 2023

Earth’s evolving geodynamic regime recorded by titanium isotopes

Posted by in categories: chemistry, particle physics, space

Powders of samples were weighed into precleaned Savillex beakers and dissolved with mixtures of 22 M HF and 14 M HNO3 acids in a 2:1 volume ratio. The modern OIBs and four reference materials (that is, BHVO-2, BCR-2, AGV-2 and BIR-1) were digested on a hot plate at 120 °C for four days. Note that all chondrite and Archaean ultramafic/mafic rock samples were digested in Parr bomb vessels at 220 °C for three days to ensure full dissolution of refractory phases. Dissolution of the dried samples in 5–10 ml 6 M HCl at 120 °C and evaporation was carried out several times to decompose the fluorides formed from HF digestion until clear solutions were obtained. An aliquot of each sample was taken and spiked with a prepared 47 Ti–49 Ti double spike to determine in advance the Ti concentration using an iCAP RQ inductively coupled plasma mass spectrometer at the Centre for Star and Planet Formation (StarPlan) at the University of Copenhagen. Afterwards, aliquots containing 6 µg Ti were taken and mixed with a 47 Ti–49 Ti double spike as described previously in ref. 34. The dried mixtures were dissolved with 6 M HCl at 120 °C overnight to ensure sample–spike equilibration.

Titanium was separated from matrix elements following a three-step purification protocol using AG1x8 (200–400 meshes) and DGA resins34,68, that is, first to separate Fe with 6 M HCl elution on AG1x8 columns, second to remove most of the major and trace elements through 12 M HNO3 elution and to collect Ti with Milli-Q H2O on DGA columns and third to purify Ti from the remaining matrix elements with 4 M HF cleaning on AG1x8 columns. An extra DGA pass can be carried out to remove trace amounts of Ca and Cr in the final Ti cuts. To destroy the resin particles and organics from column chemistry, the Ti cuts were treated with 14 M HNO3 at 120 °C before storage in 0.5 M HNO3 + 0.01 M HF acids.

Titanium isotopic compositions of the purified samples were measured using the ThermoFisher Scientific Neoma Multicollector ICP-MS. Sample solutions with 500–800 ppb Ti dissolved in 0.5 M HNO3 + 0.01 M HF were introduced into the multicollector inductively coupled plasma source mass spectrometer by means of an APEX HF desolvating nebulizer from Elemental Scientific and a sapphire injector was used instead of the quartz-made injector to reduce the production of silicon fluorides from the use of HF solvent. An actively cooled membrane desolvation component was attached after the APEX to suppress oxide formation and to stabilize the signals, and N2 gas at a flow rate of a few ml min−1 was added to improve the sensitivity. Such a setting typically provides an intensity of around 15 V on 48 Ti+ at an uptake rate of about 50 μl min−1 for a 600-ppb Ti solution under a medium mass-resolution mode.

Jul 27, 2023

Biotechnology giant: Does China now lead the world in human and agricultural genetic engineering?

Posted by in categories: bioengineering, biotech/medical, food, genetics

For many people, when they hear China and genetic engineering in the same sentence, it is often synonymous with scandal.

Jul 27, 2023

Li iontronics in single-crystalline T-Nb2O5 thin films with vertical ionic transport channels

Posted by in category: energy

The two-dimensional layered crystal structure of niobium oxide polymorph T-Nb2O5 exhibits fast Li-ion diffusion that is promising for energy storage applications. Epitaxial growth of single-crystalline T-Nb2O5 thin films with ionic transport channels oriented perpendicular to the surface are now demonstrated.

Jul 27, 2023

Russian Scientists Present 16-Qubit Quantum Computer

Posted by in categories: computing, quantum physics

The Quantum Insider (TQI) is the leading online resource dedicated exclusively to Quantum Computing.

Jul 27, 2023

Going the distance for better wireless charging

Posted by in category: energy

A better way to wirelessly charge over long distances has been developed at Aalto University. Engineers have optimized the way antennas transmitting and receiving power interact with each other, making use of the phenomenon of “radiation suppression”. The result is a better theoretical understanding of wireless power transfer compared to the conventional inductive approach, a significant advancement in the field.

Charging over short distances, such as through induction pads, uses magnetic near fields to transfer power with high efficiency, but at longer distances the efficiency dramatically drops. New research shows that this high efficiency can be sustained over long distances by suppressing the radiation resistance of the loop antennas that are sending and receiving power. Previously, the same lab created an omnidirectional wireless charging system that allowed devices to be charged at any orientation. Now, they have extended that work with a new dynamic theory of wireless charging that looks more closely at both near (non-radiative) and far (radiative) distances and conditions. In particular, they show that high transfer efficiency, over 80 percent, can be achieved at distances approximately five times the size of the antenna, utilizing the optimal frequency within the hundred-megahertz range.

‘We wanted to balance effectively transferring power with the radiation loss that always happens over longer distances,’ says lead author Nam Ha-Van, a postdoctoral researcher at Aalto University. ‘It turns out that when the currents in the loop antennas have equal amplitudes and opposite phases, we can cancel the radiation loss, thus boosting efficiency.’

Jul 27, 2023

Substance Dualism (Part 1 of 2) [HD]

Posted by in category: robotics/AI

Examining the view that mind and body are separate substances.

Note at 7:08 A reductio ad absurdum argument (one which attributes a machine with thought purely for the sake of argument, to demonstrate that genuinely absurd / contradictory consequences follow) would be valid. We can see immediately that Plantinga’s thought experiment doesn’t achieve this: failure to discern how a thinking machine is thinking indicates only lack of comprehension, not a genuine absurdity / contradiction.

Continue reading “Substance Dualism (Part 1 of 2) [HD]” »

Jul 27, 2023

July 1816: Fresnel’s Evidence for the Wave Theory of Light

Posted by in categories: education, engineering, mathematics, particle physics

Until the early 20th century, the question of whether light is a particle or a wave had divided scientists for centuries. Isaac Newton held the former stance and advocated for his “corpuscular” theory. But by the early 19th century, the wave theory was making a comeback, thanks in part to the work of a French civil engineer named Augustin-Jean Fresnel.

Born in 1,788 to an architect, the young Fresnel had a strict religious upbringing, since his parents were Jansenists — a radical sect of the Catholic Church that embraced predestination. Initially he was home-schooled, and did not show early academic promise; he could barely read by the time he was eight. Part of this may have been due to all the political upheaval in France at the time. Fresnel was just one year old when revolutionaries stormed the Bastille in 1,789, and five when the Reign of Terror began.

Eventually the family settled in a small village north of Caen, and when Fresnel was 12, he was enrolled in a formal school. That is where he discovered science and mathematics. He excelled at both, so much so that he decided to study engineering, first at the École Polytechnique in Paris, and then at the École Nacionale des Ponts et Chaussées.

Jul 27, 2023

Dropships & Drop Pods

Posted by in category: futurism

The ability to get a strike force anywhere and fast is of vast strategic value, and the future may dropships landing anywhere on a planet within minutes.

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Continue reading “Dropships & Drop Pods” »

Jul 27, 2023

Why the Big Bang might not have been the beginning of our Universe

Posted by in categories: cosmology, physics

The Big Bang marks the birth of the Universe, right? The physicists brave enough to look beyond it aren’t so sure.