Stabilized Octahedral Frameworks in Layered Double Hydroxides by Solid‐Solution Mixing of Transition Metals

Pseudocapacitors have received considerable attention, as they possess advantages of both rechargeable batteries and electric double layer capacitors. Among various active materials for pseudocapacitors, α‐layered double hydroxides (α‐TM(OH)₂, TM = transition metal) are promising due to their high specific capacities. Yet, irreversible α‐to‐β phase transitions of α‐TM(OH)₂ hinder their long‐term cyclability, particularly when the TM is nickel. Here, it is reported that binary TM ion mixing can overcome the limited cycle lives of α‐TM(OH)₂ by stabilizing the octahedral frameworks of α‐TM(OH)₂. In particular, an α‐TM(OH)₂ with equal amounts of nickel and cobalt exhibits long‐term capacity retention (89.0% after 2000 cycles) and specific capacity (206 mA h g^?1), which are better than those of individual TM counterparts. A series of analyses reveals that the improved performances originate from the synergistic effects between the TM ions; the preferred trivalent state of cobalt ions stabilizes the octahedral framework by accommodating the detrimental Jahn–Teller distortion of Ni³⁺. The stabilized framework also widens the redox swing range of the nickel up to 4+, thus, increasing the specific capacity of the corresponding α‐TM(OH)₂. This study indicates that proper mixing of TMs is a prolific approach in enhancing the vital properties of α‐TM(OH)₂, a promising family of pseudocapacitor materials.     

Information Regularized Sensor Fusion: Application to Localization With Distributed Motion Sensors

We propose the information regularization principle for fusing information from sets of identical sensors observing a target phenomenon. The principle basically proposes an importance-weighting scheme for each sensor measurement based on the mutual information based pairwise statistical similarity matrix between sensors. The principle is applied to maximum likelihood estimation and particle filter based state estimation. A demonstration of the proposed regularization scheme in centralized data fusion of dense motion detector networks for target tracking is provided. Simulations confirm that the introduction of information regularization significantly improves localization accuracy of both maximum likelihood and particle filter approaches compared to their baseline implementations. Outlier detection and sensor failure detection capabilities, as well as possible extensions of the principle to decentralized sensor fusion with communication constraints are briefly discussed.     

Growth kinetics of Streptococcus thermophilus at subbacteriostatic penicillin G concentrations

Streptococcus thermophilus may be subjected to the effects of penicillin G in contaminated milk used for yogurt production. Sensitivity of this microorganism to penicillin G has been conventionally determined by the help of penicillin G-impregnated disks placed on solid media. It was observed that the bacteriostatic penicillin G concentration was much greater in liquid media than in solid media. The conventional disk method may not be appropriate for antibiotic sensitivity determinations if the microorganisms will be used in liquid culture. A simple mathematical model simulated the growth of S. thermophilus in liquid culture. Numerical values of this model's parameters were regarded as the measure of the antibiotic effect on the culture. In penicillin G containing fresh medium, small concentrations of antibiotic decreased the specific growth rate considerably. Increasing the antibiotic concentration caused only slight additional decline. Antibiotic shock, i.e., rapidly introducing penicillin G into an actively growing antibiotic-free culture, stopped growth of the penicillin G-resistant microorganisms, and no death was observed, but a fraction of the microorganisms were killed in the wild culture. Both the wild and the resistant cultures recovered from the shock in a few hours. Addition of penicillin G-resistant microorganisms together with the antibiotic dosage into the wild culture prevented death.     

Highly Stable Nanoporous Sulfur‐Bridged Covalent Organic Polymers for Carbon Dioxide Removal

Carbon dioxide capture and separation requires robust solids that can stand harsh environments where a hot mixture of gases is often found. Herein, the first and comprehensive syntheses of porous sulfur‐bridged covalent organic polymers (COPs) and their application for carbon dioxide capture in warm conditions and a wide range of pressures (0–200 bar) are reported. These COPs can store up to 3294 mg g^?1 of carbon dioxide at 318 K and 200 bar while being highly stable against heating up to 400 °C. The carbon dioxide capacity of the COPs is also not hindered upon boiling in water for at least one week. Physisorptive binding is prevalent with isosteric heat of adsorptions around 24 kJ mol^?1. M06–2X and RIMP2 calculations yield the same relative trend of binding energies, where, interestingly, the dimer of triazine and benzene play a cooperative role for a stronger binding of CO₂ (19.2 kJ mol^?1) as compared to a separate binding with triazine (13.3 kJ mol^?1) or benzene (11.8 kJ mol^?1).