Conical stromatolites are thought to be robust indicators of the presence of photosynthetic and phototactic microbes in aquatic environments as early as 3.5 billion years ago. However, phototaxis alone cannot explain the ubiquity of disrupted, curled, and contorted laminae in the crests of many Mesoproterozoic, Paleoproterozoic, and some Archean conical stromatolites. Here, we demonstrate that ...

abstract: the present study deals with the buckling analysis of the laminated composite truncated conical sandwich shells with flexible core subjected to combined axial compressive load and external pressure. higher order governing equations of the motion are presented for conical composite sandwich shells, where they are derived from the hamilton principle. then, by the use of improved higher-...

The output of a piezoelectric nanogenerator based on ZnO nanowire is largely affected by the shape of nanowire. In order to obtain mechanically stable nanogenerator with high performance, the investigation of mechanical and electrical characteristics related to the nanowires and materials used in nanogenerators are of great interest and significance. This paper presents the various behavior of ...

Introduction: Incisive foramen in the maxilla is the oral terminus of the nasopalatine canal. This region is important in implantology, Therefore, the aim of this study was to investigate the  neurovascular anatomical variations in the maxillary anterior region, observed on cone beam computed tomography (CBCT) images. Materials &Methods: In this cross-sectional study, maxillary CBCT ima...

We show that the set of conical points of a rational function of the Riemann sphere supports at most one conformal measure. We then study the problem of existence of such measures and their ergodic properties by constructing Markov partitions on increasing subsets of sets of conical points and by applying ideas of the thermodynamic formalism. 1 Introduction. In this paper we recall from U2] the...

We investigate theoretically the generation of extreme-ultraviolet (EUV) beams carrying fractional orbital angular momentum. To this end, we drive high-order harmonic generation with infrared conical refraction (CR) beams. We show that the high-order harmonic beams emitted in the EUV/soft x-ray regime preserve the characteristic signatures of the driving beam, namely ringlike transverse intensi...

We consider Calderón’s inverse problem with partial data in dimensions n ≥ 3. If the inaccessible part of the boundary satisfies a (conformal) flatness condition in one direction, we show that this problem reduces to the invertibility of a broken geodesic ray transform. In Euclidean space, sets satisfying the flatness condition include parts of cylindrical sets, conical sets, and surfaces of re...

Meshes with planar quadrilateral faces are desirable discrete surface representations for architecture. The present paper introduces new classes of planar quad meshes, which discretize principal curvature lines of surfaces in so-called isotropic 3-space. Like their Euclidean counterparts, these isotropic principal meshes meshes are visually expressing fundamental shape characteristics and they ...