Synthesis of cyclopentadienyl gadolinium and samarium alkoxide complexes

The mixed ligand complexes [{Gd(OCMe₂-i-Pr)₂Cp}₂], [{Sm(OCMe₂-i-Pr)₂Cp}₂], and [Sm₂(OCMe₂-i-Pr)₃Cp₃] were synthesized by reacting [LnCp₃] with HOCMe₂-i-Pr. X-ray crystallographic studies show that the three complexes each have two bridging alkoxide ligands linking two metal atoms. The coordination geometries at the metals are distorted tetrahedral.     

Single‐Step Preparation of Large Area TiO2 Photoelectrodes for Water Splitting

The fast, single‐step and easily scalable production by plasma electrolytic oxidation (PEO) of large area TiO₂ electrodes with excellent photoactivity in water splitting under simulated solar light is systematically investigated here. In particular, the effects that the cell voltage (100–180 V) and the processing time (0.5–15 min) have on the electrode properties are studied. The PEO‐produced oxide layers are porous, the predominant crystalline structure shifting from anatase, to an anatase‐rutile mixture, and finally to rutile by rising the cell voltage. The electrodes show a double‐layered structure, with a more compact layer at the interface with the titanium substrate and a thick porous layer on the external surface. The photocurrent density versus wavelength reflects the phase composition, with a maximum incident photon‐to‐current efficiency of 90% at 320 nm. The highest H₂ production rate is attained with the mixed anatase‐rutile electrode prepared by 300 s‐long PEO at 150 V.     

Bark beetles as lidar targets and prospects of photonic surveillance

Forestry is raising concern about the outbreaks of European spruce bark beetle, Ips typographus, causing extensive damage to the spruce forest and timber values. Precise monitoring of these beetles is a necessary step towards preventing outbreaks. Current commercial monitoring methods are catch-based and lack in both temporal and spatial resolution. In this work, light scattering from beetles is characterized, and the feasibility of entomological lidar as a tool for long-term monitoring of bark beetles is explored. Laboratory optical properties, wing thickness, and wingbeat frequency of bark beetles are reported, and these parameters can infer target identity in lidar data. Lidar results from a Swedish forest with controlled bark beetle release event are presented. The capability of lidar to simultaneously monitor both insects and a pheromone plume mixed with chemical smoke governing the dispersal of many insects is demonstrated. In conclusion, entomological lidar is a promising tool for monitoring bark beetles.     

Designing Low Impedance Interface Films Simultaneously on Anode and Cathode for High Energy Batteries

High energy batteries urgently required to power electric vehicles are restricted by a number of challenges, one of which is the sluggish kinetics of cell reactions under low temperatures. A novel approach is reported to improve the low temperature performance of high energy batteries through rational construction of low impedance anode and cathode interface films. Such films are simultaneously formed on both electrodes via the reduction and oxidation of a salt, lithium difluorobis(oxalato) phosphate. The formation mechanisms of these interface films and their contributions to the improved low temperature performances of high energy batteries are demonstrated using various physical and electrochemical techniques on a graphite/LiNi_0.5Co_0.2Mn_0.3O₂ battery using 1 m LiPF₆‐ethylene carbonate/ethyl methyl carbonate (1/2, in weight) baseline electrolyte. It is found that the interface impedances, especially the one on the anode, constitute the main obstacle to capacity delivery of high energy batteries at low temperatures, while the salt containing fluorine and oxalate substructures used as additives can effectively suppress them.     

Yeast β(1-3),(1-6)-d-glucan films: Preparation and characterization of some structural and physical properties

Cell wall polysaccharide suspensions (mainly β-glucan) was isolated from baker's yeasts (Saccharomyces cerevisiae) and used for the preparation of films. Glycerol was added as a plasticizer. Purity and composition of the films were tested by elemental analysis, enzymatic assay of α- and β-glucans, monosaccharide composition analysis (total hydrolysis, HPAEC) and vibration spectroscopy (FTIR, FT Raman). Surface properties and the degree and type of crystallinity, together with ageing effects, were estimated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). Mechanical and thermal properties were characterized by tensile tests and difference scanning calorimetry (DSC), respectively. The prepared films were water insoluble, compact, non-porous, exhibit no pronounced crystallinity and consist of granular-like and fibre microstructures, which could be assigned as cell wall residues and released polysaccharide macromolecules. Certain structural changes in the film surface during one-year shelf storage can be related to reorientation and decomposition of surface macromolecules due to reaction with the ambient atmosphere, rather than to crystallization phenomena.     

Characterization of films made with chayote tuber and potato starches blending with cellulose nanoparticles

The aim of this study was to characterize chayotextle starch films reinforced with cellulose (C) and cellulose nanoparticle (CN) (at concentrations of 0.3%, 0.5%, 0.8% and 1.2%), using thermal, mechanical, physicochemical, permeability, and water solubility tests. C was acid-treated to obtain CN. The films were prepared by casting; potato starch and C were used as the control. The solubility of the starch films decreased with the addition of C and CN compared with its respective film without C and CN. No statistical difference (α = 0.05) was found in the films added with different concentrations of C and CN. In general, the mechanical properties were improved with the addition of C and CN, and higher values of tensile strength and elastic modulus were determined in the films reinforced with CN. The melting temperature and enthalpy increased with the addition of C and CN, and the values of both thermal parameters were higher in the films with CN than with C; the enthalpy value of the film decreased when the concentration of C or CN increased in the composite. Low concentration of C and CN is better distributed in the matrix film. The addition of C and CN in the starch films improved some mechanical, barrier, and functional properties.