Methodology of selective metallic thin film ablation from susceptible polymer substrate using pulsed femtosecond laser.

Electronic devices on flexible polymeric substrates allow new fields of applications. A maskless and flexible structuring process for such systems is offered by ablation using ultra-short pulse laser irradiation. Hereby, certain areas of a functional thin film coating (e.g. nickel-chromium) are locally removed from a substrate (e.g. polyimide) to yield the needed device structures. Micro laser patterning quality is influenced by the beam properties (beam profile, fluence) as well as by the pulse overlap, the substrate material and many other factors. A clear distinction must be made between the material ablation at the surface of a bulk material and the substrate selective removal of a thin metallic film. For the latter, general rules for the prediction of ablation results especially in the case of areal ablation, which were not known from the literature so far, are derived here in the form of mathematical criteria. A methodology for the parameter finding in different cases of ablation (dot, line, areal) is presented and exemplified using a practical example, but is also applicable to other flexible thin film based systems.

Virtual Reconstruction and Comparative Analyses of the Middle Pleistocene Apidima 2 Cranium (Greece).

The Apidima 2 fossil cranium from South Peloponnese is one of the most important hominin specimens from Southeast Europe. Nevertheless, there has been continuous controversy as to whether it represents a so-called Preneandertal/Homo heidelbergensis such as, for example, the Petralona cranium from Northern Greece or a more derived Neandertal. Recent absolute dating evidence alone cannot clarify the issue because both classifications would be possible during the respective Middle Pleistocene time span. Since only limited data were available on the cranium, there have been repeated claims for the need of a broader comparative study of the hominin. The present article presents a CT-based virtual reconstruction including corrections of postmortem fractures and deformation as well as detailed metrical and morphological analyses of the specimen. Endocranial capacity could be estimated for the first time based on virtual reconstruction. Our multivariate analyses of metric data from the face and vault revealed close affinities to early and later Neandertals, especially showing the derived facial morphometrics. In addition, comparative analyses of Apidima 2 were done for many derived Neandertal features. Here again, a significant number of Neandertal features could be found in the Apidima cranium but no conditions common in Preneandertals. In agreement with a later Middle Pleistocene age Apidima is currently the earliest evidence of a hominin in Europe with such a derived Neandertal facial morphology. The place of Apidima in the complex process of Neandertal evolution as well as its taxonomic classification are discussed as well. Anat Rec, 303:1374-1392, 2020. © 2019 American Association for Anatomy.

Optical properties of silicon titanium oxide mixtures prepared by metallic mode reactive sputtering.

In this paper different SiO(2)-TiO(2) mixtures are prepared by metallic mode reactive sputtering. The samples were sputtered from cylindrical targets in a sputter-up configuration using an additional plasma source for oxidization. The different ratios of SiO(2) and TiO(2) in the mixtures are prepared by a target sputtering power variation. Optical film properties of the mixtures such as refractive index, which is determined by ellipsometric measurements, and optical bandgap, which is measured by photometric (transmission) measurements, are investigated. The thin-film structure is investigated by x-ray diffraction analysis and the stress of the films is presented. It is shown that the metallic mode reactive sputtering in the present configuration is applicable to continuously tune optical and mechanical properties. Finally the sputtered mixed materials are compared with other optical standard materials such as Nb(2)O(5), Ta(2)O(5), HfO(2), and Al(2)O(3).

On the reliability of recent tests of the Out of Africa hypothesis for modern human origins.

In this paper we critique two recent studies that have been claimed to disprove the Out of Africa hypothesis for modern human origins (Hawks et al., 2000; Wolpoff et al., 2001). We show that the test prediction employed by Hawks et al. (2000) and Wolpff et al. (2001) is not relevant to many versions of the Out of Africa hypothesis, and that the key specimens they used are problematic in terms of morphological representativeness. We also show that there are significant problems with the character state datasets employed in the studies. Lastly, we highlight evidence that the main method used in the studies (pairwise difference analysis) is not reliable when applied to the type of data employed by Hawks et al. (2000) and Wolpoff et al. (2001). In view of the foregoing, we contend that Hawks et al.'s (2000) and Wolpoff et al.'s (2001) claim to have disproved the Out of Africa hypothesis cannot be sustained.

Virtual study of the endocranial morphology of the matrix-filled cranium from Eliye Springs, Kenya.

This paper provides the first endocranial description of the matrix-filled archaic Homo sapiens cranium from Eliye Springs, Kenya. Using CT-based 3D reconstruction, the virtually cleaned endocranial surface allowed for the assessment of more than 30 metrical and nonmetrical features, most of which are considered of phylogenetic importance. The VOXEL-MAN program used was most valuable in describing and analyzing the morphological conditions. Since many of the features have not been widely or virtually studied, a small sample of late Pleistocene/early Holocene skulls from East Africa was similarly analyzed for insight into recent variation. The comparisons between Eliye Springs and the modern African specimens showed that the endocranial morphology of this probably later Middle Pleistocene hominid falls into, or close to, the modern ranges of variation for most features. This study also addresses the problems of variation and phylogenetic significance of many of the features, and highlights the need for basic studies on the variability and relevance of such endocranial traits in human evolution.

Pathological alterations in the archaic Homo sapiens cranium from Eliye Springs, Kenya.

This paper reports on the results of a first computerized tomography (CT)-based study of the Middle Pleistocene matrix-filled skull KNM-ES 11693 from Eliye Springs at Lake Turkana. Ectocranially, the hominid cranium exhibits a remarkable enlargement of the vault symmetrical to the sagittal suture and a porotic surface covering most of the vault. CT analysis further revealed a strong thickening of the cranial vault as well as other relevant aspects. Differential diagnosis suggests that the changes of the Eliye Springs cranium were probably caused by chronic anemia in the childhood or youth of this individual.