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The purpose of this paper is to introduce and analyze a new blast-wave impact-mitigation concept using advanced computational methods and tools. The concept involves the use of a protective structure consisting of bimolecular reactants displaying a number of critical characteristics, including: a high level of thermodynamic stability under ambient conditions (to ensure a long shelf-life of the protective structure); the capability to undergo fast/large-yield chemical reactions under blast-impact induced shock-loading conditions; large negative activation and reaction volumes to provide effective attenuation of the pressure-dominated shockwave stress field through the volumetric-energy storing effects; and a large activation energy for efficient energy dissipation. The case of a particular bimolecular chemical reaction involving polyvinyl pyridine and cyclohexyl chloride as reactants and polyvinyl pyridinium ionic salt as the reaction product is analyzed.

Direct simulations of single planar shockwave propagations through the reactive mixture are carried out, and the structure of the shock front examined, as a function of the occurrence of the chemical reaction. To properly capture the shockwave-induced initiation of the chemical reactions during an impact event, all the calculations carried out in the present work involved the use of all-atom molecular-level equilibrium and non-equilibrium reactive molecular-dynamics simulations. In other words, atomic bonding is not pre-assigned, but is rather determined dynamically and adaptively using the concepts of the bond order and atomic valence.

The results obtained clearly reveal that when the chemical reactions are allowed to take place at the shock front and in the shockwave, the resulting shock front undergoes a considerable level of dispersion. Consequently, the (conserved) linear momentum is transferred (during the interaction of the protective-structure borne shockwaves with the protected structure) to the protected structure over a longer time period, while the peak loading experienced by the protected structure is substantially reduced.

To the authors’ knowledge, the present work is the first attempt to simulate shock-induced chemical reactions at the molecular level, for purposes of blast-mitigation.

In the recent work, a new blast-wave impact-mitigation concept involving the use of a protective structure consisting of bimolecular reactants (polyvinyl pyridine+cyclohexyl chloride), capable of undergoing a chemical reaction (to form polyvinyl pyridinium ionic salt) under shockwave loading conditions, was investigated using all-atom reactive equilibrium and non-equilibrium molecular-dynamics analyses. The purpose of this paper is to reveal the beneficial shockwave dispersion/attenuation effects offered by the chemical reaction, direct simulations of a fully supported single planar shockwave propagating through the reactive mixture were carried out, and the structure of the shock front examined as a function of the extent of the chemical reaction (i.e. as a function of the strength of the incident shockwave). The results obtained clearly revealed that chemical reactions give rise to considerable broadening of the shockwave front. In the present work, the effect of chemical reactions and the structure of the shockwaves are investigated at the continuum level.

Specifically, the problem of the (conserved) linear-momentum accompanying the interaction of an incident shockwave with the protective-structure/protected-structure material interface has been investigated, within the steady-wave/structured-shock computational framework, in order to demonstrate and quantify an increase in the time period over which the momentum is transferred and a reduction in the peak loading experienced by the protected structure, both brought about by the occurrence of the chemical reaction (within the protective structure).

The results obtained clearly revealed the beneficial shock-mitigation effects offered by a protective structure capable of undergoing a chemical reaction under shock-loading conditions.

To the authors’ knowledge, the present manuscript is the first report dealing with a continuum-level analysis of the blast-mitigation potential of chemical reactions.

The purpose of this paper is to provide a critical and in‐depth review of the present status and recent developments in synthetic methodologies, reaction engineering, process design and quality control aspects associated with the manufacture of mono and multifunctional acrylate monomers.

This paper reviews commercially important UV cure mono and multifunctional acrylate monomers. It covers their synthesis, catalyst, and appropriate solvents for azeotropic removal of byproducts. The detail discussion on catalysis, basis of design of reactors and commercial plant and the process engineering associated with the manufacture has been supported through citation of synthesis of various acrylate monomers. The methodologies adopted for determination of physical, chemical and compositional characterisation of acrylate monomers have been presented. In addition, the guidelines regarding the bulk storage and commercial handling of acrylates have been reviewed.

The reaction engineering of esterification reaction between acrylic acid and polyol has been worked out to provide the basis for selection of reactors. The reaction has been modeled as a series – parallel complex reaction for providing explanation for generation of various byproducts/adducts and multiple esters.

The detailed discussion on formation, characterisation and treatment of Michael adducts and purification of acrylate monomers will be relevant for new researchers for further development. A review of guidelines on selection of homogenous and heterogeneous catalysts for synthesis of acrylate monomers has been presented.

Since the related literature on acrylate monomers is scarce, scattered and proprietary, the consolidated coverage in one paper will be useful.

The purpose of this paper is to examine the unsteady pressure-driven flow of a reactive third-grade non-Newtonian fluid in a channel filled with a porous medium. The flow is subjected to buoyancy, suction/injection asymmetrical and convective boundary conditions.

The authors assume that exothermic chemical reactions take place within the flow system and that the asymmetric convective heat exchange with the ambient at the surfaces follow Newton’s law of cooling. The authors also assume unidirectional suction injection flow of uniform strength across the channel. The flow system is modeled via coupled non-linear partial differential equations derived from conservation laws of physics. The flow velocity and temperature are obtained by solving the governing equations numerically using semi-implicit finite difference methods.

The authors present the results graphically and draw qualitative and quantitative observations and conclusions with respect to various parameters embedded in the problem. In particular the authors make observations regarding the effects of bouyancy, convective boundary conditions, suction/injection, non-Newtonian character and reaction strength on the flow velocity, temperature, wall shear stress and wall heat transfer.

The combined fluid dynamical, porous media and heat transfer effects investigated in this paper have to the authors’ knowledge not been studied. Such fluid dynamical problems find important application in petroleum recovery.

Partially‐decoupled upwind‐based total‐variation‐diminishing (TVD) finite‐difference schemes for the solution of the conservation laws governing two‐dimensional non‐equilibrium vibrationally relaxing and chemically reacting flows of thermally‐perfect gaseous mixtures are presented. In these methods, a novel partially‐decoupled flux‐difference splitting approach is adopted. The fluid conservation laws and species concentration and vibrational energy equations are decoupled by means of a frozen flow approximation. The resulting partially‐decoupled gas‐dynamic and thermodynamic subsystems are then solved alternately in a lagged manner within a time marching procedure, thereby providing explicit coupling between the two equation sets. Both time‐split semi‐implicit and factored implicit flux‐limited TVD upwind schemes are described. The semi‐implicit formulation is more appropriate for unsteady applications whereas the factored implicit form is useful for obtaining steady‐state solutions. Extensions of Roe's approximate Riemann solvers, giving the eigenvalues and eigenvectors of the fully coupled systems, are used to evaluate the numerical flux functions. Additional modifications to the Riemann solutions are also described which ensure that the approximate solutions are not aphysical. The proposed partially‐decoupled methods are shown to have several computational advantages over chemistry‐split and fully coupled techniques. Furthermore, numerical results for single, complex, and double Mach reflection flows, as well as corner‐expansion and blunt‐body flows, using a five‐species four‐temperature model for air demonstrate the capabilities of the methods.

Future trends in surface coating developments must consider energy and raw materials prices, working cost, ecological imperatives and advances in technology. To be successful, a coating simultaneously must be non‐polluting, easy to apply in a short time and able to give good final properties. In the field of epoxy systems, these different aspect are well illustrated in the cases of thermosetting epoxy powder coatings and also with liquid epoxy acrylates which can be crosslinked by U. V. or β radiations, without heating.

Samples of loomstate cotton fabric were first treated with aqueous potassium permanganate solution at different concentrations in the presence of a non‐ionic wetting agent. The samples were then washed and treated using solutions containing methacrylic acid, wetting agent and acid or basic dye along with citric acid of different concentrations at different temperatures for different times. The critical properties of the fabric such as graft yield (expressed as carboxyl content m.eq/100g cellulose), colour strength before and after soaping and percentage loss in colour strength due to soaping were found to depend on the concentrations of KMnO₄, citric acid and methacrylic acid as well as duration of the treatment. Based on the results obtained, treating formulations consisting of KMnO₄ (0.1g/l), citric acid (0.1g/l), methacrylic acid (50 per cent), dye (1 per cent) and wetting agent (2g/l) was considered appropriate for concurrent grafting and dyeing of the said fabrics provided that the treatment was carried out at 90°C for 60 minutes.