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Short Note on Superconductivity at Ambient Temperature and Pressure in Silver-Embedded Gold Nano-particles: a Goldsmith Job Ahead
Very recent observation of superconductivity (arXiv: 1807.08572 ) in both transport (resistance versus temperature) and magnetization (zero field cooled) at around 235 K and above has obviously raised many eyebrows. The experimentalists in particular are more thrilled than the theoreticians. Although the results presented in the paper are clean and both transport and magnetization measurements do approve the observation of superconductivity to some extent (the diamagnetic shielding fraction is low), the problem is to synthesize/fabricate the material. This I called the “goldsmith” job, primarily because one has to deal with gold and silver nano-particle combination/amalgamation/alloying or even who knows the interfacial new phase, which could be superconducting. This short note is written to let the spark continues, and the interesting work of Thapa and Pandey (arXiv: 1807.08572 ) is reproduced independently.
An Embedding Theorem with Anisotropy for Vector Fields
A generalization of some recent results of D. M. Stolyarov and the authors is proved.
Ultra-compact low loss electro-optical nanobeam cavity modulator embedded photonic crystal
In this paper, a hybrid electro-optical modulator based on a one-dimensional photonic crystal nanobeam cavity is proposed. The main component of the cavity builder is the indium–tin–oxide that is a transparent conductive oxide. The proposed structure is used to minimize optical losses and also to have a high-quality factor with a tunability from the distributed feedback system. The proposed modulator has a wide range of resonant tunable in a footprint of 1.892 μm{sup 2}. This structure has the ability to shift the wavelength of 1.55 μm using a very small voltage 0.1 V. Simulation results show that the proposed structure has an insertion loss of 0.027 dB, extension ratio 3.484 dB, 119.89 GHz modulation speed, and 0.59 aJ/bit modulation energy. By comparing the proposed method parameters and other modulators based on the one-dimensional photonic crystal nanobeam cavity, a significant improvement in modulation voltage, insertion losses, energy consumption, and footprint have been observed.
Thermoelectric Transport in InGaAs with High Concentration of Rare-Earth TbAs Embedded Nanoparticles
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Electron Attachment and Electron Ionization of Formic Acid Clusters Embedded in Helium Nanodroplets
We report the results of an experimental study of electron ionization of large helium nanodroplets doped with formic acid (FA). Several homologous series of cluster anions are observed, including [FA{sub n}-H]{sup −}, undissociated FA{sub n}{sup −}, and these ions complexed with one or more H{sub 2}O. Some major features resemble those observed upon sputtering of frozen FA films but they differ significantly from results obtained by electron attachment to bare FA clusters in the gas phase. The FA{sub n}{sup −} and (H{sub 2}O)[FA{sub n}-H]{sup −} series show abrupt onsets above n = 2 and 5, respectively. A prominent resonance in the anion yield occurs at 22.5 eV due to the formation of an intermediate He{sup −*}. Also observed are homologous series of [FA-H]{sup −} or [FA{sub 2}-H]{sup −} complexed with helium. The cation chemistry is dominated by the production of protonated formic acid clusters, [FA{sub n}H]{sup +}, but various other homologous cluster ion series are observed as well. .
Machine learning for arbitrary single-qubit rotations on an embedded device
Here, in this study, we present a technique for using machine learning (ML) for single-qubit gate synthesis on field-programmable logic for a superconducting transmon-based quantum computer based on simulated studies. Our approach is multi-stage. We first “bootstrap” a model based on simulation with access to the full state vector for measuring gate fidelity. We next present an algorithm, named adapted randomized benchmarking (ARB), for fine-tuning the gate on hardware based on measurements of the devices. We also present techniques for deploying the model on programmable devices with care to reduce the required resources. While the techniques here are applied to a transmon-based computer, many of them are portable to other architectures.
Time and spatial resolution of slip and twinning in a grain embedded within a magnesium polycrystal
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Melting and solidification of lead nanoparticles embedded in Aluminium-Gallium matrices
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Simple Parameterization of Embedded Atom Method Potentials for FCC Alloys
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Lattice physics calculations using the embedded self-shielding method in polaris, Part II: Benchmark assessment
Polaris is a 2D multigroup lattice physics capability in the SCALE code system used for the analysis of light water reactor fuel designs. In this work, verification and validation results of Polaris in SCALE 6.2 are presented. The SCALE/KENO continuous-energy Monte Carlo code is used as a reference to compare the results of more than 2,000 combinations of pressurized water reactor and boiling water reactor lattice designs and state points. Radiochemical assay measurements were also used to assess the accuracy of depletion calculations. Results show that Polaris, with ENDF/B-VII.1 cross section library, produces accurate lattice physics data for core simulators.
Non-Markovian dynamics of quantum open systems embedded in a hybrid environment
Quantum systems of interest are typically coupled to several quantum channels (more generally environments). In this paper, we develop an exact stochastic Schrödinger equation for an open quantum system coupled to a hybrid environment containing both bosonic and fermionic particles. Such a stochastic differential equation may be obtained directly from a microscopic model through employing a classical complex Gaussian noise and a non-commutative fermionic noise to simulate the hybrid bath. As an immediate application of our developed stochastic approach, we show that the evolution of the reduced density matrix can be derived by taking the average over both the bosonic noise and the fermionic noise. Three specific examples are given in this paper to illustrate that the hybrid quantum trajectory is fully consistent with the standard quantum mechanics. Our examples also shed new light on the special features exhibited by the fermionic bath and bosonic bath. - Highlights: • Exact dynamic equation for quantum open system coupled to a hybrid bath is derived. • The equation is consistent with standard quantum mechanics. • The dynamic equation derived is useful in exploring non-Markovian features.
Model-based predictive control of multi-stage air-source heat pumps integrated with phase change material-embedded ceilings
This paper presents a model-based predictive control strategy to optimize the operations of phase change material (PCM) ceiling panels coupled with a multi-stage air-source heat pump. A three-stage prototype heat pump unit has been built and tested in the laboratory, with the low and medium stages designed for space heating/cooling and the high compression stage dedicated to charging of the PCM energy storage. To facilitate optimal control of the integrated heat pump system, a mixed-integer linear programming formulation is derived through linearization of the heat pump model and a mixed-integer reformulation of the PCM dynamic governing equations. A predictive control strategy is synthesized based on the resultant control formulation and implemented in a receding horizon scheme that optimizes the PCM charging and the zone temperature schedules simultaneously to leverage both the passive (associated with building construction materials) and active (PCM) storage capacities of a building. The control strategy has been tested along with three benchmarking control scenarios using a co-simulation platform for a prototypical detached house in Atlanta, GA. In this study, test results showed that application of the proposed control strategy to the PCM-integrated heat pump could provide 27.1% electricity cost savings while a fine tuned rule-based control strategy could achieve cost savings of 20.4%, compared to a baseline case without PCM storage, under a time-of-use rate tariff.
Development and evaluation of a multi-functional heat pump with embedded thermal storage
We developed and tested a novel multi-functional packaged vertical heat pump designed for multi-family buildings, capable of providing space cooling, space heating, water heating, and energy storage integration. The system employs a 3-speed scroll compressor and supports energy-efficient cooling and heating across different ambient conditions, while utilizing both indoor and outdoor air sources for water heating. Key performance metrics include an integrated energy efficiency ratio of 18.0 for cooling, a heating seasonal performance factor of 10.0, and a coefficient of performance (COP) of 2.1 for heating in cold climates down to −15 ˚C. Additionally, the system delivers an annual water heating COP greater than 4.0, with outstanding performance in combined space cooling and water heating modes, achieving a total COP of 8.8 by recovering condenser waste heat. The heat pump also demonstrated thermal energy storage capabilities, integrating with phase change material systems to store heating and cooling energy. Furthermore, this versatile system offers a promising solution for improving energy efficiency and sustainability in multi-family buildings, providing high-performance heating, cooling, and water heating across a range of climates.