Topological Zero-Thickness Cosmic Strings

In this paper, based on the gauge potential decomposition and the $\phi-$mapping theories, we study the topological structures and properties of the cosmic strings that arise in the Abelian-Higgs gauge theory in the zero-thickness limit. After a detailed discussion, we conclude that the topological tensor current introduced in our model is a better and more basic starting point than the generally used Nambu-Goto effective action for studying cosmic strings.Comment: 10 pages, no figure

Generation of entangled squeezed states in atomic Bose-Einstein condensates

A method for producing entangled squeezed states (ESSs) for atomic Bose-Einstein condensates (BECs) is proposed by using a BEC with three internal states and two classical laser beams. We show that it is possible to generate two-state and multi-state ESSs under certain circumstances.Comment: 6 pages, 1 figur

Priprava toplinskoizolacijske žbuke s FGD-gipsom

Thermal insulation gypsum plaster was prepared from flue gas desulphurization (FGD) gypsum. K12 is more recommendable as foaming agent, when the mass fraction of K12 is around 0.1 %, the setting time and compressive strength meet the requirements of gypsum-based construction materials. In the meanwhile, the thermal conductivity is 0.18 W m–1 K–1, which can be used as a thermal insulation material. The hemihydrate mixtures obtained, allow the design of a new wall structure, which is more efficient as a thermal insulation system. The wall heat transfer coefficient test was carried out to compare thermal performance of two different thermal insulation systems. Compared with the thermal performance of a conventional system, the heat transfer coefficient of the new system was reduced by 5.6 %. Finally, energy-saving analysis of a building was carried out to compare the energy-saving effect of the conventional and new systems of building. The energy-savings of the building with the new system increased by almost 2 %, thus resulting in low energy consumption of the building.Toplinskoizolacijska gipsana žbuka izrađena je od gipsa nastalog odsumporavanjem dimnog plina (FGD). Uz maseni udjel sredstva za pjenjenje (K12) 0,1 % toplinska provodnost iznosi 0,18 W m–1 K–1 pa se materijal može upotrijebiti za toplinsku izolaciju. Žbuka i sredstvo za pjenjenje uključeni su u novi tip zidne toplinske izolacije. Koeficijent prijenosa topline novog izolacijskog sustava određen je eksperimentalno i iznosi 0,608 W m–2 K–1. Na temelju analize zaključeno je da se s novim sustavom ušteda energije u zgradi može popeti do 66,99 %. Novi materijal može imati velik utjecaj na energijsku učinkovitost zgrade