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The National Highway Traffic Safety Administration issued guidelines on the safe transport of pediatric patients to lessen the chance of injury during ambulance transport. However, adherence to these standards have been slow to take hold. The objective of this quality improvement study is to evaluate barriers and facilitators of safe transport at the individual, organizational, and societal levels and identify improvement opportunities in the safe transport of pediatric patients. This study was designed using an implementation science framework. Six focus groups were held with EMS clinicians to assess knowledge, behaviors, barriers, and facilitators of safe pediatric transport. Four interviews were conducted with EMS leadership to characterize organizational safe transport practices and policies. Detailed notes were taken during focus groups; interviews were recorded and transcribed. Qualitative data were analyzed using a thematic content analysis approach where team members reviewed transcripts using an established framework and identified major and minor themes related to safe pediatric transport. Three focus groups were conducted in a hospital setting and three were conducted at EMS base stations. Interview participants included two paramedic leaders, an ambulance service chief executive officer, and an ambulance service clinical coordinator. Recurring themes included the belief that children were inherently difficult to transport, the sentiment that training in pediatric transport is lacking, and the acknowledgement that familiarity with pediatric transport guidelines is low. Additionally, a major theme was that situational practicality can take precedence over adherence to best practice recommendations. Participants reported the presence of organizational and external barriers that made it more difficult for EMS personnel to follow safety guidelines. This included equipment unavailability, lack of clear policies, low pediatric patient volume, manufacturer design preferences, and prevailing EMS culture/norms. EMS clinicians need hands-on training and knowledge reinforcement in safe pediatric ground ambulance transport. EMS agencies should ensure that their crews have proper equipment, training, and protocols in place. Regulators and manufacturers can be catalysts for the implementation of these recommendations. Substantial change at the individual, organizational, and societal levels are needed to improve the safety of pediatric patients being transported via ground ambulance. [ABSTRACT FROM AUTHOR]

This work is motivated by the recent interest in using strain gradient theory to model the chiral behavior of elastic materials. In this paper, we derive a linear strain gradient theory for Cosserat thermoelastic materials according to the three models (types I, II and III) of Green-Naghdi theory. Models II and III permit propagation of thermal waves at finite speeds, while model I coincides with the classical Fourier's law. The thermal field is influenced by the displacement and the microrotation fields and by some additional parameters that describe the chiral behavior. We prove the well-posedness for the three models and the asymptotic behavior for models I and III by the semigroup theory of linear operators. [ABSTRACT FROM AUTHOR]

A nonlinear theory is derived for a thermoviscoelastic diffusion composite which is modeled as a binary mixture consisting of two Kelvin-Voigt viscoelastic materials. First, the basic equations of the nonlinear theory of heat and diffusion conducting viscoelastic mixtures are derived in Lagrangian description. Then, the theory is linearized and field equations are given for both anisotropic and isotropic centrosymmetric materials. We establish the necessary and sufficient conditions to get a dissipation inequality for isotropic centrosymmetric materials. With the help of the semigroup theory of linear operators, we establish the suitable framework where the linear problem is well posed. Finally, we prove that generically the solution decreases exponentially thanks to the viscous dissipation effects of the constituents. [ABSTRACT FROM AUTHOR]

In this article we derive a nonlinear theory of thermoelastic materials with microtemperatures based on the entropy balance of type III postulated by Green and Naghdi. The work is motivated by an increasing use of materials which possess thermal variation at a microstructure level such that both thermal and microtemperatures waves can propagate with finite speeds and energy dissipation. The equations of the linear theory are also obtained. Then, we use a semigroup approach to derive an existence and uniqueness result for the solutions to the anisotropic problem and to study the asymptotic behavior. Finally, we investigate the impossibility of the localization in time of solutions. [ABSTRACT FROM AUTHOR]

This article is concerned with a nonlinear theory of thermodynamics for elastic materials in which the particles are subjected to classical displacement, temperature, and mass diffusion fields and whose microelements possess microtemperatures and microconcentrations. The equations of the linear theory are also obtained. It is shown that there exists coupling between temperature, chemical potential, microtemperatures, and microconcentrations even for isotropic bodies. With the help of the semigroup theory of linear operators, we prove the well-posedness of the linear anisotropic problem and we study the asymptotic behavior of the solutions. [ABSTRACT FROM PUBLISHER]

During the larval stages of development, the imaginal disc ofDrosphila Melanogasteris composed by a monolayer of epithelial cells, which undergo a strain actively produced by the cells themselves. The well-organized collective contraction produces a stress field that seemingly has a double morphogenetic role: it orchestrates the cellular organization towards the macroscopic shape emergence while simultaneously providing a local information on the organ size. Here we perform numerical simulations of such a mechanical control on morphogenesis at a continuum level, using a three-dimensional finite model that accounts for the active cell contraction. The numerical model is able to reproduce the (few) known qualitative characteristics of the tensional patterns within the imaginal disc of the fruit fly. The computed stress components slightly deviate from planarity, thus confirming the previous theoretical assumptions of a nonlinear elastic analytical model, and enforcing the hypothesis that the spatial variation of the mechanical stress may act as a size regulating signal that locally scales with the global dimension of the domain. [ABSTRACT FROM PUBLISHER]

This article considers the linear theory of thermoelastic materials with inner structure whose particles, in addition to the classical displacement and temperature fields, possess microtemperatures. We discuss some non-standard problems within the context of the dynamic boundary value problems. In fact, we use the Lagrange-Brun type identities combined with some differential inequalities in order to show that the final boundary value problem associated with the linear thermoelasticity with microtemperatures has at most one solution in appropriate classes of displacement-temperature-microtemperature fields. Furthermore, we study the constrained motion of a prismatic cylinder made of a thermoelastic material with microtemperatures and subjected to final given data that are proportional, but not identical with, the respective values at a prescribed early time. We show that certain cross-sectional integrals of the solution spatially evolve with respect to the axial variable. Conditions are derived upon the proportionality coefficients in order to show that the cross-sectional integrals exhibit alternative behavior and, in particular for a semi-infinite cylinder, that there is either at least exponential growth or at most exponential decay. [ABSTRACT FROM AUTHOR]

In the present paper we consider the linear theory of thermoelasticity of type III for anisotropic and inhomogeneous materials as developed by Green and Naghdi (1992, 1995). We consider the general initial-boundary value problems associated with the theory in concern and then we identify some mild constitutive hypotheses that lead to appropriate energetic measures of solutions. On this basis we are able to prove some new uniqueness and continuous data dependence theorems. When the boundary surface is maintained at zero thermal displacement, we are able to obtain uniqueness and continuous data dependence results by using only the positiveness of the density mass, the positive definiteness of the elasticity tensor and the positive definiteness of the heat conductivity tensor, without any sign defined assumption upon the specific heat. These results are established by means of new techniques which are essentially different from those previously used for the classical theory of thermoelasticity. [ABSTRACT FROM AUTHOR]

In the present paper we consider a prismatic cylinder occupied by an anisotropic homogeneous compressible linear thermoelastic material that is subject to zero body force and heat supply and zero displacement and thermal displacement on the lateral boundary. The motion is induced by a harmonic time-dependent displacement and thermal displacement specified pointwise over the base. We establish some spatial estimates for an appropriate cross-sectional measure associated with the amplitude of the corresponding harmonic vibration in the high frequency range that describe how the amplitude evolves with respect to the axial distance to the excited base. In fact, in the high frequency range we establish certain algebraical estimates that predict decay or growth slower than that for the low frequency range. [ABSTRACT FROM AUTHOR]

In the present paper we consider a prismatic cylinder occupied by an anisotropic homogeneous compressible linear thermoelastic material that is subject to zero body force and heat supply and zero displacement and thermal displacement on the lateral boundary. The motion is induced by a harmonic time-dependent displacement-thermal displacement specified pointwise over the base. We establish some spatial estimates for some appropriate cross-sectional measures associated with the transient and steady state solutions that describe how they evolves with respect to the axial distance to the excited base. For the transient solutions a domain of influence is observed inside which a measure of the solution decays exponentially with respect to the axial variable, while outside of the domain the solution vanishes. For the harmonic in time vibrations we establish spatial estimates describing how the amplitude of vibration evolves with respect to the axial variable, provided the frequency is lower than a critical value. All results are established for the thermoelastic materials whose constitutive coefficients satisfy strong ellipticity conditions. [ABSTRACT FROM AUTHOR]

This paper concerns with the linear theory of micropolar thermoelasticity for materials with voids. We construct the fundamental solution of the system of differential equations in the case of steady oscillations in terms of elementary functions. Some basic properties of this solution are established. [ABSTRACT FROM AUTHOR]

In this paper we study the spatial behaviour for a large class of isotropic and homogeneous porous thermoelastic materials for which the constitutive coefficients are supposed to satisfy some relaxed positive definiteness conditions. By using some appropriate measures, we are able to establish results describing the spatial behaviour of transient and steady-state solutions in these enlarged classes of thermoelastic porous materials. [ABSTRACT FROM AUTHOR]

The present article is concerned with the reconstruction of the position and the size of a linear crack located in the elastic half-space parallel to its boundary surface, in the case of anti-plane (shear) deformation. It is assumed that the input data is given by the results obtained from measurements of the boundary surface settlement. A respective direct problem is first formulated as a certain hyper-singular integral equation, and then it is stated that the studied inverse problem can be reduced to an optimization problem for strongly nonlinear functional. Three different methods of optimization are constructed, and the results predicted numerically by these methods are compared on some examples. [ABSTRACT FROM AUTHOR]

In this article we study the reconstruction of the geometry of elliptic voids located in the elastic wedge, in frames of an antiplane two-dimensional problem. The wedge domain is bounded by a pair of straight boundaries. The first boundary is horizontal, and the second one is inclined at some angle. We assume that a known point force is applied to the horizontal boundary surface of the wedge, whose other face is fixed or is free from load. It is also assumed that the defect is unknown and that we can measure the shape of the surface over a certain finite-length interval of the same side where the outer force is applied. Such measurements can in principle be performed experimentally, but for our numerical experiments we carried out them by solving the respective direct problem, with the use of boundary element method (BEM). Then it is shown that an explicit form of Green's function can be constructed when the interior angle of the wedge is an integer part of 180°. For these cases, we construct an algorithm to restore the position, the size, and the orientation of the elliptic void. Some numerical examples demonstrate the good stability of the proposed algorithm. [ABSTRACT FROM AUTHOR]

Two time-weighted measures are introduced for studying the spatial behavior of the thermoelastic processes in an isotropic thermoelastic body in order to relax the hypotheses of positive definiteness on the thermoelastic coe3cients. For the first measure we establish some spatial estimates describing the spatial behavior of solutions for the class of thermoelastic materials for which the Lamé moduli λ and μ range so that μ > 0 and λ > - &frac43;μ. The second measure allows us to establish spatial estimates describing the spatial behavior of the thermoelastic processes in an isotropic and homogeneous thermoelastic material for which the Lamé moduli range so that μ > 0 and -2μ < λ < 0. [ABSTRACT FROM AUTHOR]

This article studies the uniqueness and continuous dependence problems for the thermoelastic processes backward in time. Using some Lagrange–Brun identities combined with Gronwall's lemma, it is shown that the boundary final value problem associated with the linear thermoelasticity has at most one solution provided that some mild requirements are assumed concerning the thermoelastic coefficients. Some estimates are outlined that exhibit continuous dependence with respect to the final data, on the whole time interval without any kind of constraint on the solutions. [ABSTRACT FROM AUTHOR]

In this article we use the results of Green and Naghdi Proc. Roy. Soc. London A, vol. 432, pp. 171-194, 1991 and vol. 357, pp. 253-270, 1977 and J. Elasticity, vol. 31, pp. 189-209, 1993] to establish a theory of micropolar thermoelasticity that permits propagation of thermal waves at a finite speed. A solution of Galerkin type for homogeneous and isotropic bodies is also established. This solution is used to study the effect of a concentrated heat source. The continuous dependence of the solution with respect to body loads and initial data is finally studied. [ABSTRACT FROM AUTHOR]

The article presents a study concerning the modeling of mass transfer using thermo-mechanic coupling of surface and volumetric growth for the morphogenesis of seashells. It mentions that a continuous configurational theory is defined to understand the mechanical and biochemical feedbacks coordinating the mass transport and processes and evolution of growth. It adds that the proposed model can be used for evolution of nodules, spike, and bumps.