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.

Double-temperature ratchet model and current reversal of coupled Brownian motors

Abstract: On the basis of the transport features and experimental phenomena observed in studies of molecular motors, we propose a double-temperature ratchet model of coupled motors to reveal the dynamical mechanism of cooperative transport of motors with two heads, where the interactions and asynchrony between two motor heads are taken into account. We investigate the collective unidirectional transport of coupled system and find that the direction of motion can be reversed under certain conditions. Reverse motion can be achieved by modulating the coupling strength, coupling free length, and asymmetric coefficient of the periodic potential, which is understood in terms of the effective potential theory. The dependence of the directed current on various parameters is studied systematically. Directed transport of coupled Brownian motors can be manipulated and optimized by adjusting the pulsation period or the phase shift of the pulsation temperature.

Low-temperature liquid extraction as a method of the pretreatment of phenol samples for reversed-phase HPLS

Abstract: A new procedure was developed for the liquid—liquid extraction of phenols from aqueous solutions With acetonitrile. It is based on the ability of aqueous acetonitrile systems to form immiscible phases in the temperature range 271—269 K. The resulting duration of analysis is 40–45 min, the partition coefficient is 45–140, and the recovery is 97.8–99.2%. The procedure was proved applicable for sample pretreatment followed by determination by reversed-phase HPLC.

Analysis on Influencing Factors of Indoor Air Quality and Measures of Improvement on Modern Buildings

Abstract: The average person spends up to 80 percent of his or her time indoors. Because indoor concentrations of contaminants are often higher than the corresponding outdoor concentrations, indoor air quality (IAQ) clearly is an environmental component of significance regarding human health and comfort. This paper introduces the main category and source of main air pollutions that influences modern building indoor environment. Analyze the main influencing factors on indoor IAQ of the air conditioning system. Put forwards some measures to improve indoor IAQ of modern building.

Digital modeling of traffic safety management systems

Abstract: The paper addresses techniques for applying structural methods to study complex systems of various purposes to substantiate functional organization and control. Those systems include traffic safety assurance (TSA) systemsin general, their individual control channels managing the level of traffic safety ensured by main macro factors affecting it, as well as their individual functional elements. The logic of developing a complete set of causes behind grave road accidents, both primary and final, which is missing in the Russian practice, is presented Typical models of setting up the organization of controlled, functionally compulsory activities of various kinds, and a structural mathematical model developed for a fully observable system that provides an opportunity for the determination of mechanisms underlying the formation and digital evaluation of its main functional properties, such as controllability, accuracy of conversion of input, controlling and disturbing signals into the final, systemic and local results, are provided. A structural and functional model of a nation-wide multi-channel system to ensure traffic safety as the basis to support all functional properties and procedures for breaking-down into various functionally separate subsystems at any level of the hierarchy is described.Main advantages of using methods for the functional and structural modeling of systems, relevant for practical tasks,are shown. Among those advantages are the following: the possibility of using those methods in systems of any category and designation ranging from technical, man-machine, and organizational systems to large systems — combinations of complex systems having different functional (internal) organization. It is shown that they can be presented in a digital format and used to carry out system researches in the absence of initial information. Organizational management systems, where linguistic variables are taken as functions of transforming input signals into output signals, can be given as an example. Such linguistic variables change in the range of "1,0", boundaries of which correspond to activities performed in accordance with the requirements established or not performed at all.It is shown that,in systems of organizational management,the latter advantage can be implemented rather easily in terms of procedures. Moreover, it is able to ensure the transformation of non-systemic activities on traffic safety assurance into strictly systemic activities, i.e. into transparent, observable, predictable, and capable of continuous improvement activities up to the status where the "zero mortality" on Russian roads is achieved.