The polarization behaviour for six species of Scarab beetles from the Chrysina genus is investigated with Mueller Matrix Spectroscopic Ellipsometer (MMSE). The m41 element of the matrix, which is related to the circular polarization behaviour, is analysed. The ellipticity, degree of polarization and azimuth angle are also presented to get a better understanding of the polarization effect. The measurements were done with a dual rotating compensator ellipsometer. The measured wavelength region was from 240 to 1000 nm and the angle of incidence from 25° to 75° in most of the cases. In general very high ellipticities (near circular) are reported. All specimens studied reflect both right- and left-handed polarized light. Depending on the species, two general types of polarization behaviour were observed. Chrysina macropus and Chrysina peruviana showed m41 values close to 0. Green stripes on Chrysina gloriosa showed similar polarization behaviour whereas gold stripes on the same beetle had much more pronounced m41 variations. Large m41 variations were also observed for Chrysina argenteola, Chrysina chrysargyrea and Chrysina resplendens. Four specimens of Chrysina resplendens show different m41 patterns suggesting differences in their structures.

Light reflected from the scarab beetles Cetonia aurata (C. aurata) and Chrysina gloriosa (C. gloriosa) has left-handed polarization. In this work the polarizing properties and structural characteristics of the cuticles of these two beetles are investigated with two different techniques: scanning electron microscopy (SEM) and Mueller-matrix spectroscopic ellipsometry (MMSE). SEM is used to get cross section images of the epicutucle and the endocuticle. Thicknesses around 18 μm were measured for both layers for C. aurata and between 12 and 16 μm for C. gloriosa. A layered structure is observed in both beetles. In addition, a cusp-like structure is also observed in C. gloriosa. MMSE showed left-handed near-circular polarization of light reflected on both beetles. For C. aurata this is observed in a narrow wavelength range (500-600 nm) and for C. gloriosa in a wider wavelength range (400-700 nm) when measured on golden areas of the cuticle. C. gloriosa also has green areas where the reflected light was linearly polarized. The results are used in regression modelling. A good model approximation was found for C. aurata for angles up to 60 whereas a good starting point for future work was reached for C. gloriosa.

Thesis (MPhil (Ancient Studies)--University of Stellenbosch, 2008. / A particular motif in Egyptian art is that of avians. This is frequently depicted in a significant number and variety of visual sources from the tomb of Tutankhamun (KV 62) (1336-1327 BC) and other find contexts throughout Egyptian history from c. 3000 BC, but is little understood. The motif mostly depicts an avian creature with wings outstretched, talons grasping the Egyptian hieroglyph symbol for eternity (shen). In some instances the avian’s falcon or vulture body or parts of the body is/are replaced with parts of another creature, namely that of a snake, cobra, ram, human, duck, or a hieroglyph sign. A study was undertaken to assess how and why this avian motif was composed and what the function in Egyptian culture was. A manual search of published material for relevant visual sources depicting specific versions of the avian motif was undertaken and selected sources were indexed into a representative graphical database including one hundred and ninety-one items. Textual sources (academic literature and literature from ancient Egypt) were then consulted to support and/or expand on the iconographic, symbolic, and functional aspects of the motif: - At the iconographic level, the historical development and ‘structural dynamics’ of the motif are investigated to deduce the artistic rules that applied to its creation. - At the symbolic level, the symbolic meaning of the artwork is ascertained by theorizing on the meaning of the motif and its parts in an Egyptian context. - At the functional level, the function of the artwork is ascertained by investigating how the motif’s symbolism was intended to be applied to benefit the individual. The results of this research is that the avian motif developed over time according to strict artistic rules; that it symbolized the king, eternity and protection; and that its function was to protect the king in all phases of his existence in a political and mythological context in order to ensure that the he would attain an eternal life in the afterlife. In the mind of the ancient Egyptian this was achieved through the transference of the avian motif’s magical qualities to the user. The intended outcome of this study is to highlight the avian motif’s importance in the context of the ancient Egyptian culture.