New eco-friendly low-cost binders for Li-ion anodes

In the production of commercial Li-ion batteries, the active materials slurries are generally prepared using polyvinylidene fluoride (PVdF) as binder because of its good adhesion properties and electrochemical stability. Unfortunately, there are some disadvantages related to the use of PVdF: the most important is the use of toxic and environmentally unfriendly solvents, such as N-methyl-pyrrolidone (NMP), and the second is the high costs. In the light of these considerations, it seemed straightforward to investigate the suitability of some water-soluble, inexpensive, and eco-friendly materials to test as alternative binders (sodium alginate, chitosan tragacanth gum, gelatin). The rheological properties of these materials have been investigated in addition to the electrochemical characterization. Furthermore, graphite electrodes with PVdF, carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR) binders have been considered for sake of comparison. We found that some of these water-soluble binders, besides good electrochemical performances, showed a high adhesion to the current collector and a good electrochemical stability under the experimental conditions employed, which makes them interesting for the next generation of Li-ion batteries.     

Evaluation of the biosafety of cyanoacrylate adhesive in vitro

This paper considers the evaluation of the biosafety of cyanoacrylate adhesive in vitro on human multipotent mesenchymal stem cells. This adhesive is intended for medical use, in particular, for X-ray and endovascular interventions. A toxicity study was carried out in a culture of multipotent mesenchymal stem cells isolated from human subcutaneous fat. As a result of the work, the concentration of cyanoacrylate adhesive in lipiodol was chosen, which has the lowest toxicity.     

Asymptotics of cylindrical functions in the complex domain: II

We obtain asymptotic formulas uniform with respect to the index p > 0 for the Hankel functions H _p ^(j) (z) (j = 1, 2) for large |z| in the complex domain. These formulas generalize those known for the real argument.     

Studies of electrode structures and dynamics using coherent X-ray scattering and imaging

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Trace of order (−1) for a string with singular weight

Mathematical Notes - The Sturm–Liouville problem on a finite closed interval with potential and weight of first order of singularity is studied. Estimates for the s-numbers and eigenvalues of...     

Cyclic modules with ∞-simplicial faces and the cyclic homology of A ∞-algebras

Mathematical Notes - A chain bicomplex for A ∞-algebras, which generalizes the Tsygan chain bicomplex in the theory of cyclic homology of associative algebras, is constructed by using the...     

Local dynamics of a second-order differential-difference equation with large delay at the first derivative

Mathematical Notes -     

Accelerated reference systems in AdS space

We consider reference systems of uniformly accelerated observers in anti-de Sitter space. We construct coordinate transformations for the transition from an inertial reference system to a uniformly accelerated reference system for all acceleration values, both greater and less than critical. The basis for the construction are the Beltrami coordinates, natural coordinates for describing a uniformly accelerated motion because geodesics in anti-de Sitter space in these coordinates become straight lines, i.e., can be described by linear functions. Because translations of space–time coordinates in anti-de Sitter space are non-Abelian, a nontrivial problem of defining the comoving inertial reference system arises. Constructing the coordinate system of an accelerated observer using this auxiliary comoving inertial reference system requires additional transformations that not only equalize the velocities of the two systems but also equalize the system origins. The presence of a critical acceleration in anti-de Sitter space leads to a difference in explicit expressions in passing to an accelerated coordinate system for accelerations greater and less than critical.     

The structure of utility functions ensuring the existence of an exact potential in a strategic game

Strategic games in which the profit of each participant is the sum of local profits gained by means certain “objects” and shared by all players using these objects are considered. If each object satisfies a regularity condition, then the game has an exact potential. Both universal classes of potential games considered previously in the literature, overflow games and games with structured utility functions, are contained in the class under consideration and satisfy the regularity condition.     

On the mean value parametrization of natural exponential families — a revisited review

It is well known that any natural exponential family (NEF) is characterized by its variance function on its mean domain, often much simpler than the corresponding generating probability measures. The mean value parametrization appeared to be crucial in some statistical theory, like in generalized linear models, exponential dispersion models and Bayesian framework. The main aim of the paper is to expose the mean value parametrization for possible statistical applications. The paper presents an overview of the mean value parametrization and of the characterization property of the variance function for NEF’s. In particular it introduces the relationships existing between the NEF’s generating measure, Laplace transform and variance function as well as some supplemental results concerning the mean value representation. Some classes of polynomial variance functions are revisited for illustration. The corresponding NEF’s of such classes are generated by counting probabilities on the nonnegative integers and provide Poisson-overdispersed competitors to the homogeneous Poisson distribution.