Fréedericksz-Like Transition in a Biaxial Smectic- A Phase

The two main classes of liquid-crystal (LC) phases of rodlike molecules are nematics, where the rods align in the same direction (the nematic director n), and smectics, where the rods not only are aligned but also form layers. The electro-optic effects in LC devices that are a backbone in today’s display industry mainly use the Fréedericksz transition, which is the bulk reorientation of a surface-anchored nematic by an electric field. Conventional (uniaxial) smectics do not present a Fréedericksz transition, because, due to their layered structure, the director reorientation would distort the layers, which would cost too much energy. In a worldwide ongoing effort to extend the variety of LC compounds suitable for applications in the display industry, bent- shaped molecules have recently raised much attention, since they present multiple new LC phases with unusual properties. In this paper, we report on a structural and electro-optic study of the LC phases of a bent-shaped dimer. On cooling from the isotropic liquid, this compound shows a usual nematic (N), a twist- bend nematic (NTB), and a biaxial smectic-A phase (Sm Ab). Quite surprisingly, contrary to usual smectics, Sm Ab presents a remarkable electro-optic response, with low ( < 4 V) voltage threshold, no reorganization of the smectic layers, and low ( < 1 ms) response time (i.e., 30 times faster than the N phase at higher temperature). We interpret this unexpected electro-optic effect as a Fréedericksz transition affecting the secondary director m of the Sm Ab, and we model it by analogy with the usual Fréedericksz transition of the n director of the uniaxial N phase. Indeed, a Fréedericksz transition affecting only m in this biaxial fluid smectic does not alter its layered structure and costs little energy. From the point of view of applications, thanks to its low relaxation time, this “biaxial” Fréedericksz transition could be exploited in electro-optic devices that require fast switching

Investment and Optimization of Resources within Constructions Assembly Enterprises

The conformation of enterprises to market economy has determined the commitment of some attributes and risks specific to this economy: personalization of demand, prices determined through the mechanism of market, market fluidity, atomization of demand and supply, sale-oriented production. The conformation of enterprises to market economy has determined the commitment of some attributes and risks specific to this economy: personalization of demand, prices determined through the mechanism of market, market fluidity, atomization of demand and supply, sale-oriented production

THE IMPACT OF ORIGIN ON CREATING A CULT BRAND: THE CASE OF APPLE

This paper introduces the concept of a cult brand for a more accurate understanding of the extreme loyalty that consumers show towards specific brands. The article focuses on the brand Apple and it explores the elements for which it is considered a cult brand and the impact of its origin on sustaining its cult appeal. Based on the fact that many brands rely on emotional characteristics to obtain consumers’ interest and attention, the country responsible for their conception is usually a warranty for quality and respect, features transferred to consumers. Through an exploratory research, based on investigation of secondary information as a data collection method, the research focuses on Apple's corporate mythology, its brand name, its geographical provenance and also the community surrounding it. The results of the study revealed that brand origin had a major role in creating the image that Apple sustained in the last decades, the conclusion reinforced the idea that on a solid foundation can be built a complex structure

Brentano's mathematical foundation of science

I examine Brentano's strategic positioning between German Idealism and British Empiricism, exemplified by Kant and Mill, focusing on the idea of mathematics as foundational science. For Brentano mathematics is both logically and chronologically prior to all other sciences. However, the 1874 Psychologie vom empirischen Standpunkte does not give a complete enough picture of Brentano's philosophy of mathematics, discussion of which must be based on textual evidence from his lecture notes and manuscripts, particularly Megethologie. Here Brentano clarifies that mathematics is not inductive, but a purely deductive and a priori science. Against Mill, Brentano argues that induction in the sciences is justified by the calculus of probability, which is founded on a priori mathematical deduction. Through the analysis of Brentano's mathematical foundations of science and comparative analysis of his critique of Kant and Mill, we can better understand Brentano's project of philosophy as science

Extruded Nucleoli of Human Dental Pulp Cells

Background and Objectives: The dental pulp stem cells are highly proliferative and can differentiate into various cell types, including endothelial cells. We aimed to evaluate the ultrastructural characteristics of the human dental pulp cells of the permanent frontal teeth. Materials and Methods: Human adult bioptic dental pulp was collected from n = 10 healthy frontal teeth of five adult patients, prior to prosthetic treatments for aesthetic purposes. Tissues were examined under transmission electron microscopy. Results: We identified cells with a peculiar trait: giant nucleoli resembling intranuclear endoplasmic reticulum, which mimicked extrusion towards the cytoplasm. These were either partly embedded within the nuclei, the case in which their adnuclear side was coated by marginal heterochromatin and the abnuclear side was coated by a thin rim of ribosomes, or were apparently isolated from the nuclei, while still being covered by ribosomes. Conclusions: Similar electron microscopy features were previously reported in the human endometrium, as nucleolar channel system; or R-Rings induced by Nopp140. To our knowledge, this is the first report of extruded nucleolar structure in the dental pulp. Moreover, the aspect of giant extruded nucleoli was not previously reported in any human cell type, although similar evidence was gathered in other species as well as in plants

La \uabmetaf\uedsica de la experiencia interior\ubb clave teor\ue9tica de la estructura relacional de la persona.

Riflessione sull'esperienza interiore come esperienza metafisica della relazionalit\ue0 accessibile all'essere uman