Directly Deposited Antimony on a Copper Silicide Nanowire Array as a High-Performance Potassium-Ion Battery Anode with a Long Cycle Life

Antimony (Sb) is a promising anode material for potassium-ion batteries (PIBs) due to its high capacity and moderate working potential. Achieving stable electrochemical performance for Sb is hindered by the enormous volume variation that occurs during cycling, causing a significant loss of the active material and disconnection from conventional current collectors (CCs). Herein, the direct growth of a highly dense copper silicide (Cu₁₅Si₄) nanowire (NW) array from a Cu mesh substrate to form a 3D CC is reported that facilitates the direct deposition of Sb in a core-shell arrangement (Sb@Cu₁₅Si₄ NWs). The 3D Cu₁₅Si₄ NW array provides a strong anchoring effect for Sb, while the spaces between the NWs act as a buffer zone for Sb expansion/contraction during K–cycling. The binder-free Sb@Cu₁₅Si₄ anode displays a stable capacity of 250.2 mAh g⁻¹ at 200 mA g⁻¹ for over 1250 cycles with a capacity drop of ≈0.028% per cycle. Ex situ electron microscopy revealed that the stable performance is due to the complete restructuring of the Sb shell into a porous interconnected network of mechanically robust ligaments. Notably, the 3D Cu₁₅Si₄ NW CC is expected to be widely applicable for the development of alloying-type anodes for next-generation energy storage devices.     

Temperature compensation of total power radiometers

This paper describes a new technique to compensate output variations of total power radiometers due to physical temperature changes of the instrument. This technique performs the correction without the addition of expensive microwave hardware required in Dicke switching or many other widely used methods. A characterization period, over which the input antenna temperature is known, indicates the appropriate output adjustment needed for a change in physical temperature of the radiometer. The method effectively corrects the output in an example radiometer system built with inexpensive commercially available parts. For a 30-K variation in physical temperature, the measured data shows an improvement from 60-K peak-to-peak error to 6.9 K with an average absolute error of 1.1 K.     

Broiler skin sampling for optimum recovery of Salmonella spp

The objective of this research was to determine the appropriate sample size (1, 5, or 10 g) and location (neck, breast, or vent) from which to sample processed poultry skin for Salmonella spp. Postkill, prescald broiler carcasses were used to help ensure that Salmonella spp. would be found. Mean Salmonella spp. counts from skin samples of 1 g (2.91 log10 CFU/g) were significantly lower (P < 0.05) than skin samples of 5 and 10 g: 3.52 log10 CFU/g and 3.42 log10 CFU/g, respectively. Mean Salmonella spp. counts from breast (3.62 log10 CFU/g) or neck (3.40 log10 CFU/g) skin samples were significantly higher (P < 0.05) than counts from vent skin samples (2.84 log10 CFU/g). Neck skin is the preferred sampling location because it contained a representative number of Salmonella spp., it had a slightly higher incidence of Salmonella spp. than vent skin, and removal of neck skin for microbiological testing did not decrease the quality grade of the bird, as would the removal of breast skin. Research results will increase the accuracy and precision of the microbiological analytical procedures for processed poultry by providing guidelines for the amount and location of skin to be sampled, as well as the preparatory procedures involved to release the Salmonella spp. from the skin samples.     

The Performance of the Adaptive Aggregation Mechanism (AAM) Under Mixed Traffic Loads

The adaptive packet aggregation algorithm (AAM) has been shown to have a superior performance over the first-in first-out (FIFO) algorithm in terms of the throughput and delay (Deng and Davis in International conference on wireless communications and signal processing 2013 (WCSP2013), Hangzhou, China, pp 449–504, 2013; 20th IEEE symposium on communications and vehicular technology in the Benelux 2013 (IEEE SCVT 2013), Namur, 2013). In this paper, we will show that when compared with the FIFO and smallest-size first-served algorithms, the AAM algorithm has the best performances in terms of the trade-off between the overhead saving and the average delay under mixed traffic loads in wireless LANs. The simulation results show that the AAM algorithm produces the largest average aggregate packet size.     

Low-crosstalk code-division multiplexed interferometric array

The results obtained using code-division multiplexing with an array of eight sensors are reported. It is demonstrated that crosstalk levels approximately -60 dB can be achieved using this approach using return-to-zero pulse coding.<>     

On the mechanics of functional asymmetry in bipedal walking

This paper uses two symmetrical models, the passive compass-gait biped and a five-link 3-D biped, to computationally investigate the cause and function of gait asymmetry. We show that for a range of slope angles during passive 2-D walking and mass distributions during controlled 3-D walking, these models have asymmetric walking patterns between the left and right legs due to the phenomenon of spontaneous symmetry-breaking. In both cases a stable asymmetric family of gaits emerges from a symmetric family of gaits as the total energy increases (e.g., fast speeds). The ground reaction forces of each leg reflect different roles, roughly corresponding to support, propulsion, and motion control as proposed by the hypothesis of functional asymmetry in able-bodied human walking. These results suggest that body mechanics, independent of neurophysiological mechanisms such as leg dominance, may contribute to able-bodied gait asymmetry.     

Synthesis of notched antenna patterns for wideband processing

Antenna patterns can be designed to have broad notches in regions where clutter and jamming are expected to be received. A number of narrowband pattern synthesis techniques exist to design notched antenna patterns, but they break down in the presence of wideband signals on arrays which employ a combination of phase and time steering. The authors derive definitions for wideband antenna patterns and present a new synthesis procedure which can be used to design notched patterns for signals having specified bandwidths on any type of array     

Lossless,Passive Transportation of Low Surface Tension Liquids Induced by Patterned Omniphobic Liquidlike Polymer Brushes

Surfaces enabling directional liquid transportation are of great interest for a wide range of applications such as water collection, microfluidics, and heat transfer systems. Surfaces capable of lossless, long-range passive transportation of low surface tension (LST) liquids using wettability patterned, liquidlike coatings with minimal contact angle hysteresis are reported. Lossless LST droplet travel distances over 150 mm are achieved, enabled by a two-phase transportation mechanism: morphological transformation from a bulge to a channel shape, followed by directional transportation along the asymmetrical wedge-shaped channel. The developed surfaces can split, merge, and precisely transport various low-surface tension liquids, including alcohols, alkanes, and solvents. The developed transportation strategy can also enhance LST liquid dropwise condensation through continuous removal of the condensate, even on horizontally positioned surfaces without the assistance of gravity.     

Images of a First‐Order Spin‐Reorientation Phase Transition in a Metallic Kagome Ferromagnet

First‐order phase transitions, where one phase replaces another by virtue of a simple crossing of free energies, are best known between solids, liquids, and vapors, but they also occur in a wide range of other contexts, including even elemental magnets. The key challenges are to establish whether a phase transition is indeed first order, and then to determine how the new phase emerges because this will determine thermodynamic and electronic properties. Here it is shown that both challenges are met for the spin reorientation transition in the topological metallic ferromagnet Fe₃Sn₂. The magnetometry and variable temperature magnetic force microscopy experiments reveal that, analogous to the liquid–gas transition in the temperature–pressure plane, this transition is centered on a first‐order line terminating in a critical end point in the field‐temperature plane. The nucleation and growth associated with the transition is directly imaged, indicating that the new phase emerges at the most convoluted magnetic domain walls for the high temperature phase and then moves to self‐organize at the domain centers of the high temperature phase. The dense domain patterns and phase coexistence imply a complex inhomogenous electronic structure, which can yield anomalous contributions to the electrical conductivity.     

Open‐Shell Donor–Acceptor Conjugated Polymers with High Electrical Conductivity

Conductive polymers largely derive their electronic functionality from chemical doping, processes by which redox and charge‐transfer reactions form mobile carriers. While decades of research have demonstrated fundamentally new technologies that merge the unique functionality of these materials with the chemical versatility of macromolecules, doping and the resultant material properties are not ideal for many applications. Here, it is demonstrated that open‐shell conjugated polymers comprised of alternating cyclopentadithiophene and thiadiazoloquinoxaline units can achieve high electrical conductivities in their native “undoped” form. Spectroscopic, electrochemical, electron paramagnetic resonance, and magnetic susceptibility measurements demonstrate that this donor–acceptor architecture promotes very narrow bandgaps, strong electronic correlations, high‐spin ground states, and long‐range π‐delocalization. A comparative study of structural variants and processing methodologies demonstrates that the conductivity can be tuned up to 8.18 S cm^?1. This exceeds other neutral narrow bandgap conjugated polymers, many doped polymers, radical conductors, and is comparable to commercial grades of poly(styrene‐sulfonate)‐doped poly(3,4‐ethylenedioxythiophene). X‐ray and morphological studies trace the high conductivity to rigid backbone conformations emanating from strong π‐interactions and long‐range ordered structures formed through self‐organization that lead to a network of delocalized open‐shell sites in electronic communication. The results offer a new platform for the transport of charge in molecular systems.