2,799 research outputs found
Topological and Emergent Phenomena in Lattice BKT Systems
No full textThis thesis addresses the emergent electrostatics of two-dimensional, toroidal magnetic models that possess XY symmetry, providing a platform for novel investigations into the Berezinskii-Kosterlitz-Thouless (BKT) phase transition. The BKT transition drives the thermal dissociation of bound pairs of topological defects in many two-dimensional systems, including the two-dimensional XY model of magnetism. The XY model is closely analogous to the two-dimensional Coulomb gas, but can be simulated without computing the long-range interactions of the Coulombic system. This thesis elucidates this paradox by showing that Villain's approximation to the XY model is strictly equivalent to the Maggs-Rossetto (MR) electrostatic model when applied to the two-dimensional Coulomb gas. The mapping is used to probe the BKT transition through the application of the MR algorithm to the two-dimensional Coulomb gas. By simulating the Coulombic system, fluctuations in the winding of charges around the torus are shown to turn on at the BKT transition temperature. These topological-sector fluctuations in the electric field therefore signal the high-temperature phase of the transition. It is then shown that the effective critical exponent of Bramwell-Holdsworth (BH) theory can be measured in superfluid He films, which correspond to effective Coulomb gases in the limit of large but finite system size. With the Coulombic system taken as the base BKT system, it is inferred that BH theory is a general property of BKT systems
XY displacement device
No full textAn XY-displacement device (1) with a four-fold symmetry comprises a reference frame (10); an object mount (20) for holding an object (22) to be displaced; an X-manipulator (100) coupled between the reference frame (10) and the object mount (20), which provides a rigid coupling between the object mount (20) and a piezoelectric X-actuator (140), allows a Y-displacement of the object mount (20) relative to the reference frame (10), and counteracts a Z-displacement of the object mount (20) relative to the reference frame (10); ; and a Y-manipulator (200) coupled between the reference frame (10) and the object mount (20), which provides a rigid coupling between the object mount (20) and a piezoelectric Y-actuator (240), allows an X-displacement of the object mount (20) relative to the reference frame (10), and counteracts a Z-displacement of the object mount (20) relative to the reference frame (10).Applied Science
He in Nanoporous Media: 4D XY Quantum Criticality at Finite Temperatures
No full textWe review our study of critical phenomena in superfluid He confined in
nanoporous glasses. He in nanoporous media is an ideal ground to survey the
quantum phase transition of bosons. In the present work, critical phenomena
were examined using a newly developed hydrodynamic mechanical resonator. The
critical exponent of superfluid density was found to be 1.0, in
contrast to 0.67 in bulk He. We also demonstrate that the superfluid
density is proportional to with
at any finite temperatures. These are the decisive evidences for the 4D XY
criticality, which should have been observed only at 0 K, at finite
temperatures. We propose a mechanism of the quantum criticality at finite
temperatures in terms of phase alignment among the nanoscale localized Bose
condensates (LBECs) in nanopores. The proposed mechanism are discussed in the
consideration of the correlation length compared with the quantum effect.Comment: 8 pages, 5 figure
Afterword. «XY» thirty years later / Postfazione. «XY» trent’anni dopo
No full textThe «XY» magazine has a history, and this history
is linked to Roberto de Rubertis who was
the creator and “driving force” since he began
his publication, in 1986 for CEDIS, with the
title «XY dimensioni del disegno», a critical
review of studies on the representation of architecture
and the use of the image in science,
technology and art. The magazine declared
programmatically the will to stimulate and disseminate
the theoretical and applied research
produced in scientific areas of drawing and
design, collecting important contributions also
from conferences and seminars such as “The
scientific foundations of representation”, developing
over the years monographic and interdisciplinary
topics including 1968–1988
Twenty years of drawn architecture, Survey
dossier, Graphics–Architecture, Survey between
history and science, and finally The places
of epochal signs about the “suburbs” observed
from a linguistic and figurative perspective
Draft of Marketing Strategy for XY Company in Specialisation of Industrial Cooling
No full textAutorka diplomové práce si jako téma vybrala Návrh marketingové strategie pro společ-nost XY v oboru průmyslového chlazení. V teoretické části na základě rešerše odborné literatury autorka práce si objasní pojmy, které souvisí s tématem diplomové práce. V praktické části provede analýzy vnitřního a vnějšího prostředí firmy XY pomocí kvalitativního výzkumu a vlastního sběru dat. V projektové části se o závěry z těchto analýz bude opírat při zpracování marketingové strategie firmy XY. Vzhledem k tomu, že se jedná o velmi citlivé informace, bude místo názvu firmy používat označení společnost XY.The author of the thesis chose as the topic the draft of Marketing strategy for the XY company in the field of industrial cooling. The author of the work explains terms related to the topic of the thesis in the theoretical part, which is based on technical literature. In the practical part the analysis of internal and external environment of the XY company is acomplished by means of qualitative research and author's own data collection. There is also the conclusion of these analyzes based on the marketing strategy of the XY company in the project part of the work. Taking into consideration using very sensitive information, author uses in the dissertation the XY name for the original company which the work si based on.Ústav marketingových komunikac
Comparative analysis of LLM capabilities and their implementation potential in business workflows
No full textCompany XY is still growing and the processes have changed over the last few years. Therefore, they have never been drawn and analyzed systematically to see if there is any potential for optimization. For this reason, the author was commissioned to do so, and the following research questions have emerged: Are large language models capable of optimizing internal processes? What processes can be optimized? How can they be implemented? And what is the impact of set implementations? The goal of this paper is to get insights into the state of the processes and possible optimizations with a LLM
Marketing Communications of the Firm XY, s.r.o.
No full textThis thesis helps to understand the problems of marketing communication in business-to-business market. The main intention is to show the theoretical background on the example of real company called XY, s. r. o. The author tried to get familiar with the current company marketing communications and applied the theoretical knowledge, especially in the proposals to improve this communication
Complete or partial XY sex-reversed phenotype of XY Gadd45g<sup>−/−</sup> mice on a pure B6 or mixed 129/B6 background.
No full text<p>(A–F) External genitals, (G–L) internal reproductive organs (8x magnification), and (M–X) hematoxylin/eosin (HE)-stained gonad or epididymis sections from young adult Gadd45g<sup>−/−</sup> and wild type mice. External and internal (C,I) reproductive organs from B6 Gadd45g<sup>−/−</sup> XY female mice (XY-F) are morphologically indistinguishable from wild type females (B, H). HE-stained ovaries from all B6 XY-F mice appear normal and contain oocytes and follicles at different maturation stages (O), including antral follicles with oocytes (U). Corpora lutea are found in XX-F and XY-F ovaries (N,O,T,U). In contrast, a large spectrum of disorders of sexual development (DSD) is seen in Gadd45g<sup>−/−</sup> XY mice on the 129/B6 background, which can be divided into three groups. 1) Infertile XY-females (E) with female internal reproductive organs (ovary, oviduct, uteri) (K), although the ovaries usually contain only primordial follicles and interstitial cells (Q,W). 2) Infertile XY-males with male phenotype (D) and reproductive system (J; testis, epididymis, vas deferens and seminal vesicles [not shown in J]) with hypoplastic testis (compare J to G). Seminiferous tubules showed reduced spermatogenesis and interstitial cell hyperplasia (P), and no spermatozoa were present in the cauda epididymis (V) and vas deferens. 3) XY-intersex mice (F) with male and female characteristics. External genitals were male, female, or ambiguous (as in F). One side often developed a hypoplastic testis/epididymis/vas deferens (L) and the contralateral gonad, a uterus and a hypoplastic ovary/oviduct/uterus or an ovotestis with mixed ovarian and testicular tissue (L,R,X). Magnification: 5x (N,O,Q,R) or 10x (M,P,S,T,U,V,W,X).</p
Scanning the critical fluctuations: Application to the phenomenology of the two-dimensional XY model
No full textWe show how applying field conjugated to the order parameter may act as a very precise probe to explore the probability distribution function of the order parameter. Using this “magnetic-field scanning” on large-scale numerical simulations of the critical two-dimensional XY model, we are able to discard the conjectured double-exponential form of the large-magnetization asymptote.DelftChemTechApplied Science
Orthogonal projection onto the xy-plane for secondary schools
No full textTitle: Orthogonal projection onto the xy-plane for secondary schools Author: Martina Magová Department: Department of Mathematics Education Supervisor: RNDr. Vlasta Moravcová, Ph.D., Department of Mathematics Education Abstract: This thesis follows on from the bachelor thesis Position examples in an orthogonal projection onto the xy-plane with metric examples and analysis of the current state of teaching the orthogonal projection onto the xy-plane at secondary schools. It includes a variety of examples and exercises. For some of those, step-by-step constructions are available in the addendum. They have been adapted for projection using a dataprojector. The theoretical part including step-by-step constructions was also made available to the public via a webpage. The thesis is designed for secondary school students as a material for self study and as a tool for teachers, who can use the included examples and project the step-by-step constructions in class. Keywords: orthogonal projection, construction examples, position examples, metric example
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