Surface Transport Properties of Pb-Intercalated Graphene

Intercalation experiments on epitaxial graphene are attracting a lot of attention at present as a tool to further boost the electronic properties of 2D graphene. In this work, we studied the intercalation of Pb using buffer layers on 6H-SiC(0001) by means of electron diffraction, scanning tunneling microscopy, photoelectron spectroscopy and in situ surface transport. Large-area intercalation of a few Pb monolayers succeeded via surface defects. The intercalated Pb forms a characteristic striped phase and leads to formation of almost charge neutral graphene in proximity to a Pb layer. The Pb intercalated layer consists of 2 ML and shows a strong structural corrugation. The epitaxial heterostructure provides an extremely high conductivity of σ=100 mS/□. However, at low temperatures (70 K), we found a metal-insulator transition that we assign to the formation of minigaps in epitaxial graphene, possibly induced by a static distortion of graphene following the corrugation of the interface layer.

Towards distortion-free imaging of the eye

The high power of the eye and optical components used to image it result in “static” distortion, remaining constant across acquired retinal images. In addition, raster-based systems sample points or lines of the image over time, suffering from “dynamic” distortion due to the constant motion of the eye. We recently described an algorithm which corrects for the latter problem but is entirely blind to the former. Here, we describe a new procedure termed “DIOS” (Dewarp Image by Oblique Shift) to remove static distortion of arbitrary type. Much like the dynamic correction method, it relies on locating the same tissue in multiple frames acquired as the eye moves through different gaze positions. Here, the resultant maps of pixel displacement are used to form a sparse system of simultaneous linear equations whose solution gives the common warp seen by all frames. We show that the method successfully handles torsional movement of the eye. We also show that the output of the previously described dynamic correction procedure may be used as input for this new procedure, recovering an image of the tissue that is, in principle, a faithful replica free of any type of distortion. The method could be extended beyond ocular imaging, to any kind of imaging system in which the image can move or be made to move across the detector.

Van Der Waals Epitaxy of Soft Twisted Bilayers: Lattice Relaxation and Static Distortion Waves

Interfaces comprising incommensurate or twisted hexagonal lattices are ubiquitous and of great interest in the materials science and physics communities. Here we demonstrate 2D crystalline domains of soft block copolymers (BCPs) on patterned hard hexagonal lattices that provide fundamental insights into van der Waals heteroepitaxy. At moderate registration forces, it is experimentally found that these BCP-hard lattice incommensurate arrays do not adopt a simple Moiré superstructure, but instead adopt local structural deformations called static distortion waves (SDWs) a primary route to energy minimization.

Van Der Waals Epitaxy of Soft Twisted Bilayers: Lattice Relaxation and Static Distortion Waves

Interfaces comprising incommensurate or twisted hexagonal lattices are ubiquitous and of great interest in the materials science and physics communities. Here we demonstrate 2D crystalline domains of soft block copolymers (BCPs) on patterned hard hexagonal lattices that provide fundamental insights into van der Waals heteroepitaxy. At moderate registration forces, it is experimentally found that these BCP-hard lattice incommensurate arrays do not adopt a simple Moiré superstructure, but instead adopt local structural deformations called static distortion waves (SDWs) a primary route to energy minimization.

WELFARE EFFECTS OF PATENT PROTECTION IN A SEMI-ENDOGENOUS GROWTH MODEL

This paper examines how strengthening patent protection affects welfare in a nonscale quality-ladder model, which was developed by Segerstrom [American Economic Review 88, 1290–1310] and generalized by Li [American Economic Review 93, 1009–1017]. In the Segerstrom–Li model, patent protection creates no distortion in static allocation among the production sectors. In order to examine the welfare effects of strengthening patent protection adequately, we incorporate a competitive outside good into the Segerstrom–Li model. In the general model, we derive the welfare-maximizing degree of patent protection analytically by utilizing a linear approximation of the transition path. The result shows that the welfare-maximizing degree of patent protection is weaker when the market share of the outside good is positive than when it is zero. In other words, disregarding the static distortion that patent protection creates leads to excessive patent protection.

Stone in the Restoration of Architectural Heritage - Deterioration of Stone Structures Caused by Humidity

Over the centuries, stone as the elementary building material has not only been the substance used for constructing buildings but also the subject of arts and crafts. Aesthetics of stone has come into use in the Middle Ages, Renaissance and Baroque as well as architectural works implemented in the 19th and 20th century. The diversity of use but mostly the range of stone masonry and elements in the whole volume of our architectural heritage is forcing us to look for effective protection methods. The deterioration of stone structures most frequently encountered include undoubtedly the undesired water intrusion and dampness which ultimately precludes habitability of interiors, causes the loss of thermo-physical properties as well as static distortion of the object. There are multiple methods of excessive dampness rehabilitation, which are, however, in case of valuable and protected works of architecture, limited to technological procedures in compliance with the principles of heritage protection. On the case studies of redevelopment of the burgher house in Banská Štiavnica and the Prónay manor house in Lučenec, we will present the available methods of rehabilitation and determinants for utilisation of the selected method.