Solvation Rule for Solid‐Electrolyte Interphase Enabler in Lithium‐Metal Batteries

Despite the exceptionally high energy density of lithium metal anodes, the practical application of lithium‐metal batteries (LMBs) is still impeded by the instability of the interphase between the lithium metal and the electrolyte. To formulate a functional electrolyte system that can stabilize the lithium‐metal anode, the solvation behavior of the solvent molecules must be understood because the electrochemical properties of a solvent can be heavily influenced by its solvation status. We unambiguously demonstrated the solvation rule for the solid‐electrolyte interphase (SEI) enabler in an electrolyte system. In this study, fluoroethylene carbonate was used as the SEI enabler due to its ability to form a robust SEI on the lithium metal surface, allowing relatively stable LMB cycling. The results revealed that the solvation number of fluoroethylene carbonate must be ≥1 to ensure the formation of a stable SEI in which the sacrificial reduction of the SEI enabler subsequently leads to the stable cycling of LMBs.     

Synthesis and antidiabetic activity of novel triazole derivatives containing amino acids

New series of triazole derivatives coupled with amino acids 1a-h were obtained via multicomponent reaction of 2-hydroxy benzaldehyde or 2-hydroxy acetophenone with thiosemicarbazide and different amino acids. The obtained compounds were reacted with p-toluinesulfonyl chloride 2 to give the corresponding sulfonamides 3a-h . Compound 1b was allowed to react with different aromatic aldehydes or cyclic ketone under alkaline conditions to afford the expected imino compounds 4a-d and 6a-c , respectively. These compounds were allowed to react with ethyl glycolate to yield the expected thiazolidinone derivatives 5a-d or 7a-c , respectively. Structures of the newly synthesized compounds were found to be in accordance with their elemental analyses and spectral data. The obtained compounds exhibited very prominent in vitro and in vivo antihyperglycemic effect at a dose of 40 mg/kg body weight compared to the standard drug gliclazide and control. The antidiabetic effect was investigated using oral glucose tolerance test in normal and non-insulin-dependent diabetes mellitus (NIDDM) in STZ-rat model. Compounds 3a - h , 5b , 5c , 5d , 7a , 7b , and 7c showed significant activity in lowering blood glucose (more than 80%) compared to the NIDDM control.     

A regularized stiffened-gas equation of state

An alternative to the stiffened-gas equation of state is proposed that corrects for unphysical behavior, namely the returning of negative pressure values for densities lower than the reference density. The question of generalizing a given isentropic equation of state is first addressed. Then, a regularized stiffened-gas equation of state is derived, which is the main goal of this work. Finally, the use of the new equation of state is briefly illustrated for a classical computational fluid dynamics benchmark concerning the evaluation of liquid impact on a wall.     

Photophysics and kinetics of naphthopyran derivatives,part 1: General analytical solutions for the kinetics of AB(k,ϕ) and ABC(k,ϕ) systems

A new formalism allowing solution of the differential equations for kinetic systems comprising three species (ABC) linked by first‐order thermal and/or photochemical reactions is proposed. The approach is developed specifically with photochromic materials in mind, but the formalism developed is shown to be applicable to a variety of kinetic systems irradiated with monochromatic light where the photokinetic factor ( F ) is constant. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 162–174, 2005     

H2 Convergence of Solutions of a Biharmonic Problem on a Truncated Convex Sector Near the Angle π

We consider a biharmonic problem Δ²u_ω = f_ω with Navier type boundary conditions u_ω = Δu_ω = 0, on a family of truncated sectors Ω_ω in ?² of radius r, 0 < r < 1 and opening angle ω, ω ∈ (2π/3, π] when ω is close to π. The family of right-hand sides (f_ω)_{ω∈(2π/3, π]} is assumed to depend smoothly on ω in L²(Ω_ω). The main result is that u_ω converges to u_π when ω → π with respect to the H²-norm. We can also show that the H²-topology is optimal for such a convergence result.

     

Synergistic Effect of Bioactive Monoterpenes against the Mosquito,Culex pipiens (Diptera: Culicidae)

Mosquitoes represent one of the most important vectors and are responsible for the transmission of many arboviruses that affect human and animal health. The chemical method using synthetic insecticides disturbs the environmental system and promotes the appearance of resistant insect species. Therefore, this study investigated the insecticidal effect of some binary monoterpene combinations (1,8 cineole + α-pinene and carvone + R (+)-pulegone) using a mixture design approach. The fumigant toxicity was evaluated against Culex pipiens female adults using glass jars. The results show that the toxicity varies according to the proportions of each compound. Indeed, Mixture 1 (1,8-cineole + α-pinene) displayed a strong toxic effect (51.00 ± 0.86% after 24 h and 100.00 ± 0.70% after 48 h) when the pure compounds were tested at 0.25/0.75 proportions of 1,8-cineole and α-pinene, respectively. Nevertheless, the equal proportion (0.5/0.5) of carvone and R (+)-pulegone in Mixture 2 exhibited a toxic effect of 54.35 ± 0.75% after 24 h and 89.96 ± 0.14% after 48 h, respectively. For Mixture 1, the maximum area of mortality that the proposed model indicated was obtained between 0/1 and 0.25/0.75, while the maximum area of mortality in the case of Mixture 2 was obtained between 0.25/0.75 and 0.75/0.25. Moreover, the maximum possible values of mortality that could be achieved by the validated model were found to be 51.44% (after 24 h) and 100.24% (after 48 h) for Mixture 1 and 54.67% (after 24 h) and 89.99% (after 48 h) for Mixture 2. It can be said that all purev molecules tested through the binary mixtures acted together, which enhanced the insecticide’s effectiveness. These findings are very promising, as the chemical insecticide (deltamethrin) killed only 19.29 ± 0.01% and 34.05 ± 1.01% of the female adults after 24 h and 48 h, respectively. Thus, the findings of our research could help with the development of botanical insecticides that might contribute to management programs for controlling vectors of important diseases.     

A finite-element approach in stream-tube method for solving fluid and solid mechanics problems

This paper presents a theoretical formulation in which the stream-tube method (STM) is examined through a variational approach for solving solid strain and fluid flow problems with finite elements. The analysis considers a reference domain, used as computational domain, related to the physical domain by an unknown transformation function to be determined numerically. Mass conservation is automatically verified by STM. The variational approach leads to eliminate the pressure in fluid problems and avoids to set up a mixed displacement–pressure procedure in the case of incompressible solids. Examples are given for fluid flows, applications and comparisons are also provided in the bending problem in elasticity.     

Ion conductive characteristics of cross-linked network polysiloxane-based solid polymer electrolytes

A series of cross-linked network polysiloxanes containing oligoethylene oxide units, (OCH₂CH₂)_n, as internal free chains have been synthesized by performing hydrosilylation of partially PEO-substituted polysiloxane precursor with , ω-diallyl terminated poly(ethylene glycol). The polymer electrolytes were formed by complexing with LiN(CF₃SO₂)₂ electrolyte salt and exhibited superior conductive property. The σ_RT of the network polymer electrolytes is in the range of 2.50×10⁻⁵ to 1.62×10⁻⁴ S/cm and depends on the cross-linking density (in terms of Si–H amount of the siloxane precursor), repeating unit number of internal oligoethylene oxide and chain length of the cross-linker. The significant enhancement of the conductivity was observed when low molecular weight dimethyl poly(ethylene glycol) was added as plasticizer. The temperature dependence of the ionic conductivity was also studied, following the Vogel–Tamman–Fulcher (VTF) equation.     

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