Topic Review
Nonvolatile Memory-Based Spiking Neural Network Architectures
A sustainable computing scenario demands more energy-efficient processors. Neuromorphic systems mimic biological functions by employing spiking neural networks for achieving brain-like efficiency, speed, adaptability, and intelligence. Current trends in neuromorphic technologies address the challenges of investigating novel materials, systems, and architectures for enabling high-integration and extreme low-power brain-inspired computing. 
  • 395
  • 24 May 2022
Topic Review
Nonlinear Integrated Photonics
The combination of integrated optics technologies with nonlinear photonics, which has led to the growth of nonlinear integrated photonics, has also opened the way to groundbreaking new devices and applications. They have been made possible by the design of guided-wave structures, which can enhance the material’s nonlinear properties, and/or by the availability of suitable materials, with high nonlinear coefficients.
  • 672
  • 25 May 2023
Topic Review
Nonlinear Damping Identification
In recent decades, nonlinear damping identification (NDI) in structural dynamics has attracted wide research interests and intensive studies. Different NDI strategies, from conventional to more advanced, have been developed for a variety of structural types. With apparent advantages over classical linear methods, these strategies are able to quantify the nonlinear damping characteristics, providing powerful tools for the analysis and design of complex engineering structures.
  • 803
  • 05 Jan 2021
Topic Review
Non-Targeted Effects of Australian and European Synchrotrons
The Australian Synchrotron (AS) and the European Synchrotron Radiation Facility (ESRF) are best configured for a wide range of biomedical research involving animals and future cancer patients. Due to ultra-high dose rates, treatment doses can be delivered within milliseconds, abiding by FLASH radiotherapy principles. In addition, a homogeneous radiation field can be spatially fractionated into a geometric pattern called microbeam radiotherapy (MRT); a coplanar array of thin beams of microscopic dimensions. Both are clinically promising radiotherapy modalities because they trigger a cascade of biological effects that improve tumor control, while increasing normal tissue tolerance compared to conventional radiation. Synchrotrons can deliver high doses to a very small volume with low beam divergence, thus facilitating the study of non-targeted effects of these novel radiation modalities in both in-vitro and in-vivo models. Non-targeted radiation effects studied at the AS and ESRF include monitoring cell–cell communication after partial irradiation of a cell population (radiation-induced bystander effect, RIBE), the response of tissues outside the irradiated field (radiation-induced abscopal effect, RIAE), and the influence of irradiated animals on non-irradiated ones in close proximity (inter-animal RIBE).
  • 445
  • 19 Apr 2022
Topic Review
Non-equilibrium Thermodynamic Foundations of the Origin of Life
There is little doubt that life’s origin followed from the known physical and chemical laws of Nature. The most general scientific framework incorporating the laws of Nature and applicable to most known processes to good approximation, is that of thermodynamics and its extensions to treat out-of-equilibrium phenomena. The event of the origin of life should therefore also be amenable to such an analysis. The Thermodynamic Dissipation Theory of the Origin and Evolution of Life postulates that the first molecules of life (the fundamental molecules) were, at their origin, pigments dissipatively structured through photochemical and chemical reactions on the surface of the oceans from simpler and more common precursor molecules in water under the solar long-wavelength UVC (205–285 nm) light of the Archean. They were “designed” by Nature to carry out this thermodynamic imperative of absorbing light in this UVC region and then to dissipate it into heat (longer wavelength photons) released into the environment. 
  • 585
  • 13 Apr 2022
Topic Review
Node
A node is a point along a standing wave where the wave has minimum amplitude. For instance, in a vibrating guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the effective length of the vibrating string and thereby the note played. The opposite of a node is an anti-node, a point where the amplitude of the standing wave is at maximum. These occur midway between the nodes.
  • 539
  • 16 Nov 2022
Biography
Nima Arkani-Hamed
Nima Arkani-Hamed (Persian: نیما ارکانی حامد‎; born April 5, 1972) is an Iranian-American-Canadian[1][2] theoretical physicist, with interests in high-energy physics, quantum field theory, string theory, cosmology and collider physics. Arkani-Hamed is a member of the permanent faculty at the Institute for Advanced Study in Princeton, New Jersey.[3] He is also director of The Cent
  • 461
  • 01 Dec 2022
Topic Review
Night Thoughts of a Classical Physicist
Night Thoughts of a Classical Physicist is an historical novel by historian of science Russell McCormmach, published in 1982 by Harvard University Press. Set in 1918, the book explores the world of physics in the early 20th century—including the advent of modern physics and the role of physicists in World War I—through the recollections of the fictional Viktor Jakob. Jakob is an old German physicist who spent most of his career during the period of classical physics, a paradigm being confronted by the rapid and radical developments of relativistic physics in 1900s and 1910s. This conflict allows for extensive examination of the various tensions placed on Jakob by the academic environment, the German academic system, and the changing academic culture of the early 20th century. The character of Jakob, a professor at a minor German university, is an amalgam of German physicists based on archival research by McCormmach. In the novel, he recalls interactions and events, documented in extensive footnotes to genuine publications and archival sources, involving many of the well-known physicists of the late 19th and early 20th centuries. Night Thoughts, pointedly criticized for its lack of literary merit by some reviewers, was generally praised for its attempt at forging a new approach to history and historical fiction by incorporating extensive research into the text.
  • 246
  • 02 Nov 2022
Topic Review
Neutral Beam Injection
Neutral beam injection (NBI) is one method used to heat plasma inside a fusion device consisting in a beam of high-energy neutral particles that can enter the magnetic confinement field. When these neutral particles are ionized by collision with the plasma particles, they are kept in the plasma by the confining magnetic field, and can transfer most of their energy by further collisions with the plasma. By tangential injection in the torus, neutral beams also provide momentum to the plasma and current drive, one essential feature for long pulses of burning plasmas. Neutral beam injection is a flexible and reliable technique, which has been the main heating system on a large variety of fusion devices. To date, all NBI systems were based on positive precursor ion beams. In the 90s there has been impressive progress in negative ion sources and accelerators with the construction of multi-megawatt negative ion based NBI systems at LHD (H0, 180 keV) and JT-60U (D0, 500 keV). The NBI designed for ITER is a substantial challenge (D0, 1MeV, 40A) and a prototype is being constructed to optimize its performance in view of the ITER future operations. Other ways to heat plasma for nuclear fusion include RF heating, electron cyclotron resonance heating (ECRH), and ion cyclotron resonance heating (ICRH), Lower hybrid resonance heating (LH).
  • 904
  • 15 Nov 2022
Topic Review
Neuromorphic Photonic Integrated Circuits
Neuromorphic photonics is a cutting-edge fusion of neuroscience-inspired computing and photonics technology to overcome the constraints of conventional computing architectures. Its significance lies in the potential to transform information processing by mimicking the parallelism and efficiency of the human brain. Using optics and photonics principles, neuromorphic devices can execute intricate computations swiftly and with impressive energy efficiency. This innovation holds promise for advancing artificial intelligence and machine learning while addressing the limitations of traditional silicon-based computing. 
  • 192
  • 10 Jan 2024
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