The cellular composition of the adrenal medulla of sexually mature guinea pigs

The adrenal glands from 15 guinea pigs aged 90 days were used in the study. Paraffin slices were stained with Mayer haematoxylin and eosin with Masson method and silvered. The histochemical reactions were carried out for catecholamines and the biochemical determinations of catecholamines. Ultrastructural observations were also performed. In the adrenal medulla of sexually mature guinea pigs numerous epinephrocites and no noreoinefrocites were observed when histochemical methods were used. The small and large ganglion cells accompanying the supporting and neurolemmal cells formed typical gangliar weaving (medullary ganglia). Apart from epinephrocytes, small and large ganglion cells and supporting and neurolemmal cells, small intensively fluorescent (SIF) cells were also detected. Biochemical investigation revealed that the mean content of adrenaline calculated for a pair of adrenal glands was 98.87% of the pool of catecholamines, whereas the mean content of noradrenaline was 1.00%, and of dopamine 0.13%

Multiscale modelling of the textile composite materials

This paper presents an initial computational multiscale modelling of the fibre-reinforced composite materials. This study will constitute an initial building block of the computational framework, developed for the DURCOMP (providing confidence in durable composites) EPSRC project, the ultimate goal of which is the use of advance composites in the construction industry, while concentrating on its major limiting factor ”durability”. The use of multiscale modelling gives directly the macroscopic constitutive behaviour of the structures based on its microscopically heterogeneous representative volume element (RVE). The RVE is analysed using the University of Glasgow in-house parallel computational tool, MoFEM (Mesh Oriented Finite Element Method), which is a C++ based finite-element code. A single layered plain weave is used to model the textile geometry. The geometry of the RVE mainly consists of two parts, the fibre bundles and matrix, and is modelled with CUBIT, which is a software package for the creation of parameterised geometries and meshes. Elliptical cross sections and cubic splines are used respectively to model the cross sections and paths of the fibre bundles, which are the main components of the yarn geometry. In this analysis, transversely isotropic material is introduced for the fibre bundles, and elastic material is used for the matrix part. The directions of the fibre bundles are calculated using a potential flow analysis across the fibre bundles, which are then used to define the principal direction for the transversely isotropic material. The macroscopic strain field is applied using linear displacement boundary conditions. Furthermore, appropriate interface conditions are used between the fibre bundles and the matrix

Finite element modelling of braided fibres subject to large deformations

This paper presents a numerical methodology to model elastic braided fibres. Elastic transversely isotropic material was used due to the anisotropy of the strands. Large deformation finite analysis based on large rotations / small strains total Lagrangian formulation was used to account for geometrical nonlinearities. Pre-processing was necessary to insert interface elements where strands are in self contact and with other materials, followed by a potential flow analysis that was undertaken to evaluate the fibre directions for every individual strand. An FE model of a knot demonstrates the important of defining interface elements, while a three plait braided model shows the importance of using a transversely isotropic model compared to an isotropic model. A twelve strand sinnet rope (T12) was also modelled using the proposed methodology and highlights new challenges when using dierent types of braiding

Computational Modelling of Braided Fibre for Concrete Reinforcement

This paper presents numerical modelling of braided fibre, to be used as concrete reinforcement. Ultimately, a corrosive and fire resistant concrete will be produced. A Cubit script (geometry and mesh software) was created to mesh braided yarns under dierent geometric parameters. Fibres were represented using elastic transversely isotropic materials, for which the fibre directions for every yarn were precisely determined from the gradients of the resultant stream functions of potential flow problems. Applying an elastic interfaces between yarns to preventing penetration and having free sliding, convergence studies were conducted on a coarse and fine mesh, using hierarchical higher order approximation [1] for uniform p- and hp-refinement

Multi-scale finite element based time-dependent reliability analysis for laminated fibre reinforced composites.

No abstract available

Non-linear dynamic response of a cable system with a tuned mass damper to stochastic base excitation via equivalent linearization technique

Abstract: Non-linear dynamic model of a cable–mass system with a transverse tuned mass damper is considered. The system is moving in a vertical host structure therefore the cable length varies slowly over time. Under the time-dependent external loads the sway of host structure with low frequencies and high amplitudes can be observed. That yields the base excitation which in turn results in the excitation of a cable system. The original model is governed by a system of non-linear partial differential equations with corresponding boundary conditions defined in a slowly time-variant space domain. To discretise the continuous model the Galerkin method is used. The assumption of the analysis is that the lateral displacements of the cable are coupled with its longitudinal elastic stretching. This brings the quadratic couplings between the longitudinal and transverse modes and cubic nonlinear terms due to the couplings between the transverse modes. To mitigate the dynamic response of the cable in the resonance region the tuned mass damper is applied. The stochastic base excitation, assumed as a narrow-band process mean-square equivalent to the harmonic process, is idealized with the aid of two linear filters: one second-order and one first-order. To determine the stochastic response the equivalent linearization technique is used. Mean values and variances of particular random state variable have been calculated numerically under various operational conditions. The stochastic results have been compared with the deterministic response to a harmonic process base excitation