Z3Z_3 and (×Z3)3(\times Z_3)^3 symmetry protected topological paramagnets

We identify two-dimensional three-state Potts paramagnets with gapless edge modes on a triangular lattice protected by $(\times Z_3)^3\equiv Z_3\times Z_3\times Z_3$ symmetry and smaller $Z_3$ symmetry. We derive microscopic models for the gapless edge, uncover their symmetries and analyze the conformal properties. We study the properties of the gapless edge by employing the numerical density-matrix renormalization group (DMRG) simulation and exact diagonalization. We discuss the corresponding conformal field theory, its central charge, and the scaling dimension of the corresponding primary field. The discussed two-dimensional models realize a variety of symmetry-protected topological phases, opening a window for studies of the unconventional quantum criticalities between them.Comment: 33 pages, 9 figure

Peculiarities of electromagnetic oscillations generated by a charged particle crossing the planar boundary between a conducting medium and a vacuum

The peculiarities of electromagnetic oscillations generated by a charged particle moving rectilinearly and uniformly have been studied when the particle crosses a planar boundary between a conducting medium and a vacuum perpendicular to that boundary. This study is based on the relevant exact analytical solutions of Maxwell equations, and the generalized Drude-Lorentz-Sommerfeld formula has been used for the dielectric function of conducting medium in the numerical calculations. The results of our investigation indicated that a charged particle may generate large amplitude oscillations in an electric field at frequencies wherein the dispersion phenomenon is essential and the real part of the conducting material's dielectric function is negative. The results further revealed that these oscillations are localized at the planar boundary of the conducting medium and a vacuum. The possibility of using this phenomenon to generate electromagnetic radiation at large distances from the surface of a conducting medium of finite size is also discussed

BioDATA - Biodiversity Data for Internationalisation in Higher Education

BioDATA is an international project on developing skills in biodiversity data management and data publishing. Between 2018 and 2021, undergraduate and postgraduate students from Armenia, Belarus, Tajikistan, and Ukraine, have an opportunity to take part in the intensive courses to become certified professionals in biodiversity data management. They will gain practical skills and obtain appropriate knowledge on: international data standards (Darwin Core); data cleaning software, data publishing software such as the Integrated Publishing Toolkit (IPT), and preparation of data papers. Working with databases, creating datasets, managing data for statistical analyses and publishing research papers are essential for the everyday tasks of a modern biologist. At the same time, these skills are rarely taught in higher education. Most of the contemporary professionals in biodiversity have to gain these skills independently, through colleagues, or through supervision. In addition, all the participants familiarize themselves with one of the important international research data infrastructures such as the Global Biodiversity Information Facility (GBIF). The project is coordinated by the University of Oslo (Norway) and supported by the Global Biodiversity Information Facility (GBIF). The project is funded by the Norwegian Agency for International Cooperation and Quality Enhancement in Higher Education (DIKU)

Origin and spread of human mitochondrial DNA haplogroup U7

Human mitochondrial DNA haplogroup U is among the initial maternal founders in Southwest Asia and Europe and one that best indicates matrilineal genetic continuity between late Pleistocene hunter-gatherer groups and present-day populations of Europe. While most haplogroup U subclades are older than 30 thousand years, the comparatively recent coalescence time of the extant variation of haplogroup U7 (~16–19 thousand years ago) suggests that its current distribution is the consequence of more recent dispersal events, despite its wide geographical range across Europe, the Near East and South Asia. Here we report 267 new U7 mitogenomes that – analysed alongside 100 published ones – enable us to discern at least two distinct temporal phases of dispersal, both of which most likely emanated from the Near East. The earlier one began prior to the Holocene (~11.5 thousand years ago) towards South Asia, while the later dispersal took place more recently towards Mediterranean Europe during the Neolithic (~8 thousand years ago). These findings imply that the carriers of haplogroup U7 spread to South Asia and Europe before the suggested Bronze Age expansion of Indo-European languages from the Pontic-Caspian Steppe region

Models of Compact Stars in the Bimetric Scalar-Tensor Theory of Gravitation

We investigate static spherically-symmetric configurations of gravitating masses in the bimetric scalar-tensor theory of gravitation. In the gravitational sector, the theory contains the metric tensor, a scalar field and a background metric as an absolute variable of the theory. The analysis is presented for the simplest version of the theory with a constant coupling function and a zero cosmological function. We show that, depending on the value of the theory parameter, the masses for superdense compact configurations can be essentially larger compared to the configurations in general relativity

Unveiling the salinity tolerance potential of Armenian Dandur (Portulaca oleracea L.) genotypes: Enhancing sustainable agriculture and food security

This study examines the adaptation of an undocumented halophyte, Dandur, to salt stress in different soil mediums. The Dandur plant physiological, morphological, and biochemical analyses show that it can withstand salinity stress. Dandur plants grown in clay and clay loam soil experienced significant decreases in height and stem diameter under extreme salinity conditions compared to non-saline soil. The fresh weight of root and shoot decreased by 70.4% and 84.8%, respectively, and dry weight by 48.5% and 79.7%. These findings underscore the importance of maintaining saline soil conditions for plant growth. Dandur unique ability to avoid dehydration and maintain growth traits, particularly in clay soil, holds promise for further exploration in agricultural research and food security-related issues caused by climate change in saline areas of Armenia and other European countries

Sorption behavior of tritiated water on Armenian natural zeolites

Summarization: The sorptive behavior of tritiated water on natural, irradiated, chemically treated and heated at high temperatures Armenian zeolites was studied and their capacity for the separation and enrichment of tritiated water was evaluated. The distribution coefficients from the batch experiments were calculated for different zeolites and vary between 0.23 and 3.01. The influence of temperature, acidity, basicity, specific activity, electron and gamma-irradiation on sorption has been studied.Παρουσιάστηκε στο: Journal of Radioanalytical and Nuclear Chemistr