University of Architecture, Civil Engineering and Geodesy

About: University of Architecture, Civil Engineering and Geodesy is a education organization based out in Sofia, Bulgaria. It is known for research contribution in the topics: Finite element method & Beam (structure). The organization has 3808 authors who have published 3822 publications receiving 30736 citations. The organization is also known as: Sofia Polytechnic.

Optimization of manufacturing of emitter-coupled logic to decrease surface of chip

Abstract: In this paper, we introduce an approach to increase integration rate of bipolar heterotransistors. The approach based on doping of required parts of heterostructure by diffusion or implantation and optimization of annealing of dopant and/or radiation defects. As simplification of the considered approach to increase integration rate we consider possibility to used common collector.

The Comprehensive Utilization of EAF Dust and Pickling Sludge of Stainless Steel Works

Abstract: The EAF Dusts and pickling sludges generated in the stainless steel production contain a lot of valuable metals such as iron, nickel, chromium and manganese. Their compositions are similar to those of laterite nickel ore, and sometimes even better than that at the contents of nickel and chromium. But it is regret that these valuable resources were random piled up or landed fill disposal. In this paper, the typical EAF dusts and pickling sludges and reductant coke powder were mixed in appropriate ratio, and then smelted in a medium frequency induction furnace. In the smelting process, the lime powder and fluorite was added to fluxing, and the ferrosilicon powder was added to strengthen the reduction. The product nickel-chromium-iron can be used as the raw material for stainless steel or cast iron production. The technology has good social and economic benefits.

Roman domination in graphs: The class ℛUV R

Abstract: For a graph G = (V,E), a Roman dominating function (RDF) f : V →{0, 1, 2} has the property that every vertex v ∈ V with f(v) = 0 has a neighbor u with f(u) = 2. The weight of a RDF f is the sum f(V ) = Σv∈Vf(v), and the minimum weight of a RDF on G is the Roman domination number γR(G) of G. The Roman bondage number bR(G) of G is the minimum cardinality of all sets F ⊆ E for which γR(G − F) > γR(G). A graph G is in the class ℛUV R if the Roman domination number remains unchanged when a vertex is deleted. In this paper, we obtain tight upper bounds for γR(G) and bR(G) provided a graph G is in ℛUV R. We present necessary and sufficient conditions for a tree to be in the class ℛUV R. We give a constructive characterization of ℛUV R-trees using labelings.