Oriented Growth of Al2O3:ZnO Nanolaminates for Use as Electron‐Selective Electrodes in Inverted Polymer Solar Cells

Atomic layer deposition is used to synthesize Al₂O₃:ZnO(1:x) nanolaminates with the number of deposition cycles, x, ranging from 5 to 30 for evaluation as optically transparent, electron‐selective electrodes in polymer‐based inverted solar cells. Al₂O₃:ZnO(1:20) nanolaminates are found to exhibit the highest values of electrical conductivity (1.2 × 10³ S cm^?1; more than six times higher than for neat ZnO films), while retaining a high optical transmittance (≥80% in the visible region) and a low work function (4.0 eV). Such attractive performance is attributed to the structure (ZnO crystal size and crystal alignment) and doping level of this intermediate Al₂O₃:ZnO film composition. Polymer‐based inverted solar cells using poly(3‐hexylthiophene) (P3HT):phenyl‐C₆₁‐butyric acid methyl ester (PCBM) mixtures in the active layer and Al₂O₃:ZnO(1:20) nanolaminates as transparent electron‐selective electrodes exhibit a power conversion efficiency of 3% under simulated AM 1.5 G, 100 mW cm^?2 illumination.     

A novel framework based on a data-driven approach for modelling the behaviour of organisms in chemical plume tracing

We propose a data-driven approach for modelling an organism''s behaviour instead of conventional model-based strategies in chemical plume tracing (CPT). CPT models based on this approach show promise in faithfully reproducing organisms’ CPT behaviour. To construct the data-driven CPT model, a training dataset of the odour stimuli input toward the organism is needed, along with an output of the organism’s CPT behaviour. To this end, we constructed a measurement system comprising an array of alcohol sensors for the measurement of the input and a camera for tracking the output in a real scenario. Then, we determined a transfer function describing the input–output relationship as a stochastic process by applying Gaussian process regression, and established the data-driven CPT model based on measurements of the organism’s CPT behaviour. Through CPT experiments in simulations and a real environment, we evaluated the performance of the data-driven CPT model and compared its success rate with those obtained from conventional model-based strategies. As a result, the proposed data-driven CPT model demonstrated a better success rate than those obtained from conventional model-based strategies. Moreover, we considered that the data-driven CPT model could reflect the aspect of an organism’s adaptability that modulated its behaviour with respect to the surrounding environment. However, these useful results came from the CPT experiments conducted in simple settings of simulations and a real environment. If making the condition of the CPT experiments more complex, we confirmed that the data-driven CPT model would be less effective for locating an odour source. In this way, this paper not only poses major contributions toward the development of a novel framework based on a data-driven approach for modelling an organism’s CPT behaviour, but also displays a research limitation of a data-driven approach at this stage.     

The effect of dispersion state on PMMA-epoxy-clay ternary blends: In situ study and final morphologies

Two PMMA-epoxy-clay ternary composites have been produced combining the polymerization induced phase separation phenomenon with two individual dispersion processing methods: a melt-blending and an ultrasonic-blending. Transmission electron microscopy (TEM) analysis shows that phase separation between PMMA and epoxy network was obtained in the form of spherical nodules in both processing methods. Organoclay particles were finely dispersed into thermosetting network and predominantly delaminated in ultrasonic-blending, whereas organoclays formed micrometer-sized aggregates in melt-blending. Wide-angle-X-ray (WAXS) studies reveal that exfoliation in the clay particles in three-phase composite was reached. Exfoliation state has been investigated using small angle X-ray scattering (SAXS) in cured systems and during curing reaction. For reacted systems, an exfoliation of platelets can occur through the de-aggregation of large agglomerates into smaller particles composed of a few platelets. For in situ SAXS studies, the distribution of the thicknesses of diffusing entities and the evolution of this distribution with reaction time were followed. This technique has shown also that movements at scale of nanometers of clay tactoids are possible even after the gel point.     

A Comparison of 2-CUSUM Stopping Rules for Quickest Detection of Two-Sided Alternatives in a Brownian Motion Model

Abstract

This work compares the performance of all existing 2-CUSUM stopping rules used in the problem of sequential detection of a change in the drift of a Brownian motion in the case of two-sided alternatives. As a performance measure, an extended Lorden criterion is used. According to this criterion, the optimal stopping rule is an equalizer rule. This paper compares the performance of the modified drift harmonic mean 2-CUSUM equalizer rules with the performance of the best classical 2-CUSUM equalizer rule whose threshold parameters are chosen so that equalization is achieved. This comparison is made possible through the derivation of a closed-form formula for the expected value of a general classical 2-CUSUM stopping rule.     

Pd (1?wt%)/LaMn0.4Fe0.6O3 Catalysts Supported Over Silica SBA-15: Effect of Perovskite Loading and Support Morphology on Methane Oxidation Activity and SO2 Tolerance

Catalysts of palladium (1?wt%) deposited over silica SBA-15 supported LaMn_0.4Fe_0.6O₃ perovskite (with perovskite loading of 10, 30 and 40?wt%), characterized by several techniques (BET, SAXS, XRD, TPR) are tested in the combustion of methane. Bulk LaMn_0.4Fe_0.6O₃ with the corresponding supported Pd catalyst are also considered for comparison purpose. Dispersing LaMn_0.4Fe_0.6O₃ oxide over silica SBA-15 improves the activity of the supported palladium catalysts to an extent depending on the perovskite loading. After ageing at 600?°C for 14?h, Pd catalysts supported over SBA-15 loaded with 30 and 40?wt% of LaMn_0.4Fe_0.6O₃, deactivate less as compared to Pd over bulk perovskite. Moreover, during catalytic tests carried out in the presence of 10?vol. ppm SO₂ these catalysts exhibit better sulphur tolerance and higher regeneration capability as compared to the Pd/LaMn_0.4Fe_0.6O₃. The superior performance of such catalysts is attributed to the good dispersion of the LaMn_0.4Fe_0.6O₃ over the SBA-15, with consequent increase of the perovskite surface area with respect to bulk perovskite. In addition, the porous structure of the silica contributes to a better stabilization of the active species against sintering and acts as a chemical sink during the catalyst exposure to SO₂.     

1,2,4-Triazole-3-Thione Analogues with a 2-Ethylbenzoic Acid at Position 4 as VIM-type Metallo-β-Lactamase Inhibitors

Metallo-β-lactamases (MBLs) are increasingly involved as a major mechanism of resistance to carbapenems in relevant opportunistic Gram-negative pathogens. Unfortunately, clinically efficient MBL inhibitors still represent an unmet medical need. We previously reported several series of compounds based on the 1,2,4-triazole-3-thione scaffold. In particular, Schiff bases formed between diversely 5-substituted-4-amino compounds and 2-carboxybenzaldehyde were broad-spectrum inhibitors of VIM-type, NDM-1 and IMP-1 MBLs. Unfortunately, these compounds were unable to restore antibiotic susceptibility of MBL-producing bacteria, probably because of poor penetration and/or susceptibility to hydrolysis. To improve their microbiological activity, we synthesized and characterized compounds where the hydrazone-like bond of the Schiff base analogues was replaced by a stable ethyl link. This small change resulted in a narrower inhibition spectrum, as all compounds were poorly or not inhibiting NDM-1 and IMP-1, but showed a significantly better activity on VIM-type enzymes, with K_i values in the μM to sub-μM range. The resolution of the crystallographic structure of VIM-2 in complex with one of the best inhibitors yielded valuable information about their binding mode. Interestingly, several compounds were shown to restore the β-lactam susceptibility of VIM-type-producing E. coli laboratory strains and also of K. pneumoniae clinical isolates. In addition, selected compounds were found to be devoid of toxicity toward human cancer cells at high concentration, thus showing promising safety.     

Glass Transition of Extruded Wheat,Corn and Rice Starch

Commercial wheat, corn and rice starch were extrusion cooked under a specific mechanical energy input (SME) ranging from 81 to 365 Wh/kg (288 to 1314 kJ/kg). Extrusion cooking at low and high SME resulted in products having significant differences in molecular weight distribution and having crystalline structures of the V‐ and E‐type, as determined by gel permeation chromatography and X‐ray diffraction analysis. Differential scanning calorimetry revealed that the glass transition temperature (T_g) of the extruded starches was independent of the botanical source, the degree of extrusion‐induced molecular fragmentation and the formation of the V‐ and E‐type crystalline structures. The obtained master curve, defined by the relationship between water content and T_g of the amorphous starch, may be used as a predictive tool in modelling the extrusion process of starch or starch containing blends, especially with regard to the formation of the morphological structure and texture attributes of directly expanded products.