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Non-invasive optical diagnostic methods allow important information about studied systems to be obtained in a non-destructive way. Complete diagnosis requires information about the chemical composition as well as the morphological structure of a sample. We report on the development of an opto-mechanical probe that combines Raman spectroscopy (RS) and optical coherence tomography (OCT), two methods that provide all the crucial information needed for a non-invasive diagnosis. The aim of this paper is to introduce the technical design, construction and optimization of a dual opto-mechanical probe combining two in-house developed devices for confocal RS and OCT. The unique benefit of the probe is a gradual acquisition of OCT and RS data, which allows to use the acquired OCT images to pinpoint locations of interest for RS measurements. The parameters and the correct functioning of the probe were verified by RS scanning of various samples (silicon wafer and ex vivo tissue) based on their OCT images - lateral as well as depth scanning was performed. Both the OCT and RS systems were developed, optimized and tested with the ultimate aim of verifying the functionality of the probe. Picture: Schematic illustration and visualization of the developed RS-OCT probe.

We have conducted the first comprehensive molecular phylogeny of the tribe Cichlasomatini including all valid genera as well as important species of questionable generic status. To recover the relationships among cichlasomatine genera and to test their monophyly we analyzed sequences from two mitochondrial (16S rRNA, cytochrome b) and one nuclear marker (first intron of S7 ribosomal gene) totalling 2236 bp. Our data suggest that all genera except Aequidens are monophyletic, but we found important disagreements between the traditional morphological relationships and the phylogeny based on our molecular data. Our analyses support the following conclusions: (a) Aequidens sensu stricto is paraphyletic, including also Cichlasoma (CA clade); (b) Krobia is not closely related to Bujurquina and includes also the Guyanan Aequidens species A. potaroensis and probably A. paloemeuensis (KA clade). (c) Bujurquina and Tahuantinsuyoa are sister groups, closely related to an undescribed genus formed by the 'Aequidens'pulcher-'Aequidens'rivulatus groups (BTA clade). (d) Nannacara (plus Ivanacara) and Cleithracara are found as sister groups (NIC clade). Acaronia is most probably the sister group of the BTA clade, and Laetacara may be the sister group of this clade. Estimation of divergence times suggests that the divergence of Cichlasomatini started around 44Mya with the vicariance between coastal rivers of the Guyanas (KA and NIC clades) and remaining cis-andean South America, followed by evolution of the Acaronia-Laetacara-BTA clade in Western Amazon, and the CA clade in the Eastern Amazon. Vicariant divergence has played importantly in evolution of cichlasomatine genera, with dispersal limited to later range extension of species within genera.

A procedure to model fiber-reinforced composites containing pores of irregular shapes is presented. Closed-form expressions for contributions of fibers and pores into effective elastic moduli are provided. The procedure is applied to predict the transverse elastic properties of unidirectional carbon/carbon composites (carbon fibers in pyrolytic carbon matrix) densified by chemical vapor infiltration. Infiltration treatment results in the formation of irregularly shaped pores randomly oriented in the plane perpendicular to the direction of fiber (transverse plane). These pores are analyzed using a numerical conformal mapping technique, and their contribution to the effective elastic properties is expressed in terms of the cavity compliance contribution tensor. Components of this tensor are found for a variety of typical pore shapes.

A computational procedure to calculate the contribution of irregularly shaped inclusions into the effective moduli of two-dimensional elastic solids is proposed. This procedure is based on the analysis of a representative volume element subjected to a prescribed macrostress. For each type of inclusion, the compliance contribution tensor is constructed using a combination of Kolosov–Muskhelishvili complex variable technique and numerical conformal mapping. Application of this procedure to regularly shaped inhomogeneities produces results that are in good correspondence with analytical predictions. The effective properties are first derived in the approximation of non-interacting inclusions. Then, several first-order micromechanical models for interacting inclusions are considered.

In this paper, we discuss the effect of porosity on the effective e lastic properties of unidirectional carbon / carbon composites (carbon fibers in pyrolytic carbon matrix) densifi ed by chemical vapor infiltration (CVI). The resulting composite consists of carbon fibers embedded in a porous matrix of pyrolytic carbon (Pyro-C). Such materials tend to ha ve very complex microstructure and to predict their effective mechanical propertie s, it is necessary to analyze them on different lengths scales. The four-level hierarchical materia l model has been proposed in (1). In dependence on the CVI conditions pores, with geometry, forms between fiber s with pyro-C coating (2,3). It is well known in the composite material theory that elast ic moduli of unidirectional composites in longitudinal direction can be predicted with good accuracy by the so-called rule of mixtures (4). Modeling of the effective elastic properties in the plane perpendicular to the fiber direction ( transverse elastic moduli) is a more challenging task that requires not only knowledge of the transverse elastic constants for all the constituents but als o adequate information on phases' distribution and detailed geometry. These pores are analyzed using nume rical conformal mapping procedure (5,6), and their contribution to the effective elastic propertie s is expressed in terms of the cavity compliance contribution tensor. Components of this tensor are found for a variety of typical pore shapes and compared with experimental results.

Pores and defects in real materials often have very irregular shapes. Thus, micromechanical modeling based on the analytical solutions of elasticity becomes inapplicable. The objective of this paper is to present a computational procedure to calculate the contribution of the irregularly shaped defects into the effective moduli of two-dimensional elastic solids. In this procedure, the cavity compliance tensor is constructed numerically for an individual defect, and then used in the elastic potential-based approach to predict the effective moduli of porous solids. Two computational methods are used in this paper to calculate the components of a cavity compliance tensor: finite element analysis and numerical conformal mapping. Application of this procedure to the regular hole shapes produces results that are in good correspondence with analytical predictions.

In this paper, we discuss the effect of porosity on the effective elastic properties of unidirectional carbon/carbon composites (carbon fibers in pyrolytic carbon matrix) densified by chemical vapor infiltration (CVI). It is shown that CVI treatment results in formation of irregularly shaped pores randomly oriented in the plane perpendicular to the direction of fiber (transverse plane). These pores are analyzed using numerical conformal mapping procedure, and their contribution to the effective elastic properties is expressed in terms of the cavity compliance contribution tensor. Components of this tensor are found for a variety of typical pores shapes.

This paper presents a computational procedure to calculate the contribution of the irregularly shaped defects into the effective moduli of two-dimensional elastic solids. In this procedure, the hole compliance tensor of an individual defect is constructed using the numerical conformal mapping (NCM) technique. The effective elastic properties of a porous solid are predicted in the non-interacting approximation using the elastic potential-based approach.