The mechanism of backscattering of electromagnetic waves by a pine forest in the meter wave band

A synthetic-aperture multifrequency polarimetric radar complex is used for experiments on studying the features of reflection of electromagnetic waves from pine forests. It is found that the intensity of the reflected power is proportional to the biometric characteristics of the forests. The hydrology and spatial fluctuations of the dielectric characteristics of the upper layer of the forest soil are studied at different depths. It is shown that spatial fluctuations of the soil’s dielectric characteristics can be used to explain the features of reflection from the forest. Reflection from a forest in the meter wave band at horizontal (HH) and vertical (VV) polarizations is simulated. It is found that mechanisms of reflection from the forest may be different for the HH and VV polarizations. Experimental data confirming the presence of specific effects in the radar images obtained in the meter wave band at the HH and VV polarizations are presented.     

Relation between the redox state of iron-based nanoparticles and their cytotoxicity toward Escherichia coli

Iron-based nanoparticles have been proposed for an increasing number of biomedical or environmental applications although in vitro toxicity has been observed. The aim of this study was to understand the relationship between the redox state of iron-based nanoparticles and their cytotoxicity toward a Gram-negative bacterium, Escherichia coli. While chemically stable nanoparticles (gammaFe2O3) have no apparent cytotoxicity, nanoparticles containing ferrous and, particularly, zerovalent iron are cytotoxic. The cytotoxic effects appear to be associated principally with an oxidative stress as demonstrated using a mutant strain of E. coli completely devoid of superoxide dismutase activity. This stress can result from the generation of reactive oxygen species with the interplay of oxygen with reduced iron species (Fe(II) and/or Fe(0)) or from the disturbance of the electronic and/or ionic transport chains due to the strong affinity of the nanoparticles for the cell membrane.     

Non-Flammable Liquid and Quasi-Solid Electrolytes toward Highly-Safe Alkali Metal-Based Batteries

Rechargeable alkali metal (i.e., lithium, sodium, potassium)-based batteries are considered as vital energy storage technologies in modern society. However, the traditional liquid electrolytes applied in alkali metal-based batteries mainly consist of thermally unstable salts and highly flammable organic solvents, which trigger numerous accidents related to fire, explosion, and leakage of toxic chemicals. Therefore, exploring non-flammable electrolytes is of paramount importance for achieving safe batteries. Although replacing traditional liquid electrolytes with all-solid-state electrolytes is the ultimate way to solve the above safety issues, developing non-flammable liquid electrolytes can more directly fulfill the current needs considering the low ionic conductivities and inferior interfacial properties of existing all-solid-state electrolytes. Moreover, the electrolyte leakage concern can be further resolved by gelling non-flammable liquid electrolytes to obtain quasi-solid electrolytes. Herein, a comprehensive review of the latest progress in emerging non-flammable liquid electrolytes, including non-flammable organic liquid electrolytes, aqueous electrolytes, and deep eutectic solvent-based electrolytes is provided, and systematically introduce their flame-retardant mechanisms and electrochemical behaviors in alkali metal-based batteries. Then, the gelation techniques for preparing quasi-solid electrolytes are also summarized. Finally, the remaining challenges and future perspectives are presented. It is anticipated that this review will promote a safety improvement of alkali metal-based batteries.     

Unprecedented Improvement of Single Li‐Ion Conductive Solid Polymer Electrolyte Through Salt Additive

Solid‐state lithium metal (Li°) batteries (SSLMBs) are believed to be the most promising technologies to tackle the safety concerns and the insufficient energy density encountered in conventional Li‐ion batteries. Solid polymer electrolytes (SPEs) inherently own good processability and flexibility, enabling large‐scale preparation of SSLMBs. To minimize the growth of Li° dendrites and cell polarization in SPE‐based SSLMBs, an additive‐containing single Li‐ion conductive SPE is reported. The characterization results show that a small dose of electrolyte additive (2 wt%) substantially increases the ionic conductivity of single Li‐ion conductive SPEs as well as the interfacial compatibility between electrode and SPE, allowing the cycling of SPE‐based cells with good electrochemical performance. This work may provide a paradigm shift on the design of highly cationic conductive electrolytes, which are essential for developing safe and high‐performance rechargeable batteries.     

Room temperature molten salts as lithium battery electrolyte

In the present study, are reported investigations obtained with the room temperature molten salt (RTMS) ethyl-methyl-imidazolium bis-(trifluoromethanesulfonyl)-imide (EMI-TFSI) in order to use it as solvent in lithium battery. The thermal stability, viscosity, conductivity and electrochemical properties are presented. A solution of 1m lithium bis-(trifluoromethanesulfonyl)-imide (LiTFSI) in EMI-TFSI has been used to test the electrolyte in a battery with LiCoO₂ and Li₄Ti₅O₁₂ as respectively cathode and anode materials. Cycling and power measurements have been obtained. The results have been compared with those obtained with a molten salt formulated with a different anion, BF₄⁻ and with a conventional liquid organic solvent EC/DMC containing LiTFSI. The 1m LiTFSI/EMI-TFSI electrolyte provides the best cycling performance: a capacity up to 106 mAh g⁻¹ is still delivered after 200 cycles, with 1C rate at 25 °C.     

Electrochemical properties of poly(decaviologen) in polymer media

Poly(decaviologen) (DV²⁺, 2ClO ₄ ^– ) has been prepared and used in the characterization of two redox couples; dication/cation radical ((DV²⁺, 2 ClO ₄ ^– )/(DV⁺, ClO ₄ ^– )) and cation radical/decaviologen ((DV⁺, ClO ₄ ^– )/(DV^o)) in a polyethylene oxide-LiClO₄ medium by linear potential sweep voltammetry. The (DC²⁺, 2 ClO ₄ ^– )/(DV⁺, ClO ₄ ^– ) couple has been used to determine the transport number of lithium in poly(ethylene oxide)–LiClO₄ or LiCF₃SO₃ complex media.     

Spiral Wound Reverse Osmosis Modules Decomposition into Elementary Units by Analyzing Stimulus Response Experiments: Characterization of the Solute Transfer across the Membrane

A model for spiral wound reverse osmosis modules FT30‐4040 has been developed by analyzing stimulus response experiments. Perfect mixing cells represent edthe flow and dispersed plug flow represented the membrane. The model was based on phenomenological equations describing the permeation. The identification of the Peclet number and the space‐time characterizing each dispersed plug flow led to the estimation of the tracer dispersion coefficient in the membrane. Ones new and two used composite reverse osmosis modules were tested. The decrease of the rejection properties of the used membranes was linked to the apparition of new plug flows with high dispersion coefficients within the membrane.     

Consumer responses to an off-flavor in juice in the presence of specific health claims

Adult US subjects (n=78) tasted and rated three juice samples containing 0, 0.3, and 0.6% KCl blind and informed. Three subgroups were informed that the juices contained functional ingredients to improve either (1) physical endurance and energy (2) mental alertness and memory, or (3) mood and emotional well-being. A control group received no information. Degree of liking and likelihood of consuming the juice once, twice or four times a day, for a total of four or 16 times, were rated. Adulteration with KCl decreased all ratings of liking, while information about health benefits increased ratings of liking in subgroups 1 and 2. Likelihood of consumption decreased with increasing KCl, with the increasing number of times per day, and with total dose regimen. The data suggest that the consumption of a functional food will be inversely related to the severity of off-flavor and to the required frequency and duration of consumption. No support was found for the notion that a slight off-flavor is a positive marker of health benefits to consumers.