Pedestrian-Level Wind Environment Assessment of Shenyang’s Residential Areas through Numerical Simulations

In recent decades, increasing urbanization has increased construction land shortages, which has made people pay more attention to the utilization of vertical space. The emergence of more and more high-rise buildings has affected the wind environment at the pedestrian level, especially in residential areas. In this research, the typical patterns of the layouts of residential buildings in Shenyang were investigated and summarized, and the wind environment of the residential areas of different architecture layouts was simulated according to the climatic conditions in Shenyang. After analyzing the simulation results, a typical layout mode for the residential areas in Shenyang was developed to facilitate the establishment of a favorable wind environment. In comparison with different building layouts, a staggered layout of slab buildings, half-enclosed layout of point buildings with openings on the south side, slab-point combined buildings with slab buildings on the north side, and point buildings on the south side were found to be the most suitable layouts for Shenyang’s climate. Thus, this study can provide guidance to designers and urban planners in addition to practical suggestions for residential planning.

THE DEVELOPMENT OF THE ARCHITECTURE OF FOLK SCHOOLS IN POLAND BETWEEN XIX –XX CENTURIES

The article analyzes the historical and cultural heritage of Polish rural public school architecture at the turn of the XIX and XX centuries. The evolution of the architecture of educational spaces in Poland, which took place under the influence of a combination of cultural and national traditions and a complex set of socio-political, socio-economic, internal and external factors, was considered. General concepts of styles of school facades, planning features of small schools, performed a spatial analysis of school spaces and identified its planning features. The architecture of Polish public schools in the second half of the 1920’s was largely influenced by the requirements of the new school reform accepted after the First World War. Elements that fit the postulates of school reform began to be used, but above all, it reflected conservative building traditions. Architects, in the spirit of the era, in the construction of school buildings referred to the ideas of modernism. The size and shape of windows has increased, corridors have expanded, toilets in schools have been designed, and even fountains for drinking water in school corridors. The size and number of classrooms and furnishings have also changed. As a result, it has formed a more comfortable and fully adapted modern school premises. The schools were built mainly on the initiative and funds of local communities and philanthropists. Most of the schools built during that period are still operational. The projects of these schools have developed interiors and provided typical layout of the school grounds, used advanced engineering, design and hygiene solutions that suited the spirit of the era and fully met the needs of teachers and students. That is why till now the Polish public schools are of great importance for the history of the Polish people and world architecture history.

Center-point steering analysis of tracked omni-vehicles based on skid conditions

Existing center-point steering models of a tracked omni-vehicle seldom consider the skid of the track (roller) grounding section, which is inconsistent with the actual steering process. In this study, for the three typical layout types, rectangular, hybrid, and centripetal, the steady center-point steering motion of a tracked omni-vehicle under skid conditions is analyzed and a correction model is investigated. The numerical solution of the absolute lateral offset of the steering pole is obtained, and the influences of various structural parameters on the numerical solution are discussed. The steering angular velocity reduction coefficient is calculated, and the angular velocity of vehicles is corrected. The simulation of center-point steering motion is carried out on eight virtual prototypes, and the center-point steering motion experiment is carried out on three physical prototypes. The results show that the established correction model is more in line with the steering reality of the tracked omni-vehicle, and it can play a role in correcting the center-point steering angular velocity.

Applications of Supercritical Carbon Dioxide Brayton Cycle for Nuclear Engineering

Supercritical carbon dioxide Brayton cycle is attracting increasing attention in various energy conversion systems due to its high cycle efficiency and high compactness. This chapter performs a review about the application of supercritical carbon dioxide Brayton cycle in nuclear engineering. The different cycle layouts developed from the original direct Brayton cycle are presented, in which the recompression cycle is the most typical layout. The thermodynamic analysis approach is discussed for the direct cycle and recompression cycle. Moreover, the key facilities, including heat transfer, compressor, and turbine, are outlined for the application of Brayton cycle in nuclear engineering.

Housing Question for Scholars: From a Communal House to a Cooperative

This article examines the transition from the principle of abolishing the way of life structured around the individual (communal house) to socially stratified comfortable housing (a cooperative) in the second half of the 1920s and mid-1930s. Traditionally, housing cooperatives are interpreted as an instrument of proletarian social stratification. The author studies industrial housing cooperatives of scholars, characterising the specifics of their interaction with the local authorities, clarifying their social composition, and reconstructing the peculiarities underlying the functioning and financial discipline. Using the documentation of the State Archives of the Russian Federation, the author explores the history of several Moscow, Leningrad, and regional scholarly cooperatives. Also, the author separately considers the project of the House for academic staff in Omsk illustrating the publication with an architectural drawing of a typical layout of elite accommodation. The author concludes that a short period of housing cooperation, which unfolded during the first five-year plan, could contribute to the strengthening of social stratification (scholars were taken out of the framework of general civil norms for housing), stratification within the academic community (financially successful categories of scholars were singled out), reducing the severity of the housing problem in the provinces (due to the resettlement of visiting specialists). On the other hand, the brief period cannot be considered successful due to the instability of cooperatives for researchers in the system of working housing, the small number of cooperatives and efforts to increase their administrative enlargement, the vagueness of the boundaries between municipal and cooperative housing, and, finally, the financial burden of cooperatives for scholars (with high state credit costs).

Experimental and Numerical Analyses of Steel-concrete Composite Floors

Background: The performances of composite steel-concrete slabs are strongly influenced by the connection between the concrete and the steel decking, which is essentially assured by bonding, interlocking, and adhesion. The connection can be continuous or localized by means of connectors. In order to increase the bonding between steel and concrete elements and to allow their collaboration, typically, a continuous connection with indentations or embossings is realized. Objective: In this study, the simulation of the concrete-steel bond interaction of a typical composite decking is analyzed. In particular, the objective is the investigation of the role of the main geometric parameters of the indentations or embossings that determine the effective functionality of the connection. Methods: To this scope, the results of four-point bending tests on five specimens of a typical layout of a composite floor are reported and discussed. Then, the obtained results are used to determine the shear bond strength according to the partial interaction method, by following the procedure provided by the Eurocode 4. Successively, the experimental results are exploited in order to calibrate a FE model in Abaqus software to be able to account for the basic effects involved in the shear bonding mechanism, i.e. interlocking, friction, and adhesion. Results & Conclusion: Finally, the obtained results are discussed, and the FE model is used to evaluate the geometrical and mechanical parameters influencing the longitudinal shear bonding resistance.

Reliability Analysis of Activated Sludge Process by Means of Biokinetic Modelling and Simulation Results

Analysis of wastewater treatment plant reliability is a difficult process, therefore it is often limited to selected aspects, e.g., mechanical reliability of equipment or technological availability of the process. The research presents a method of combining the above mentioned aspects in order to determine the complex operational availability index (CAVO). A hypothetical technological system with activated sludge (AS) in a typical layout (denitrification-nitrification) was selected for the studies. A number of operational scenarios have been developed, taking into account the possible mechanical failures of system components. Computer simulations with the use of Activated Sludge Model No.1 (ASM1), performed for selected scenarios allowed the determination of a complex operational availability of the system. Obtained results confirm high reliability of AS system in terms of biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS) removal (CAVO > 0.96) and indicate the necessity of further research in order to determine representative value of reliability of total nitrogen removal (from the study, CAVO-Ntot < 0.4) and to evaluate other technological solutions in terms of their complex reliability.

Stability Analysis of Grid-Connected Photovoltaic Systems with Dynamic Phasor Model

The typical layout of power systems is experiencing significant change, due to the high penetration of renewable energy sources (RESs). The ongoing evaluation of power systems is expecting more detailed and accurate mathematical modeling approaches for RESs which are dominated by power electronics. Although modeling techniques based on state–space averaging (SSA) have traditionally been used to mathematically represent the dynamics of power systems, the performance of such a model-based system degrades under high switching frequency. The multi-frequency averaging (MFA)-based higher-index dynamic phasor modeling tool is proposed in this paper, which is entirely new and can provide better estimations of dynamics. Dynamic stability analysis is presented in this paper for the MFA-based higher-index dynamical model of single-stage single-phase (SSSP) grid-connected photovoltaic (PV) systems under different switching frequencies.

Modular frame trusses of buildings

The paper describes space-planning and structural concept in source-efficient buildings that provides multiple functions of the rooms and large-span space.The main load-bearing structures of two adjacent storeys are metal trusses with parallel chords between which (between top and bottom chords) intermediate storeys are designed and the space between trusses is occupied by the free plan storeys. Bottom and top chords of the truss resist together with floor structure forming two-storey steel-reinforced concrete unit. To calculate value of deformation capacity for nodal connection a numerical experiment focused on modelling a part of building from solid finite elements has been performed. The results of performed analysis are the average values of stiffness of nodal interface of solid floor slab on corrugated deck and truss chords for finite elements KE 55 of typical layout (of flat finite elements). The obtained average values of stiffness were introduced into structural design of flat finite elements. Taking into account flexibility of floor slab that supported by middle trusses for the given structural concept leads to decreased span bending moments and increased support bending moments by 25% compared with hinge support of floor.

Effect of flow switch on two phase flow evenness based on granular magnesium

The aim of the work was to study, with the help of a laboratory setup, the influence of the existing design of the flow switch on the uniformity of movement of a two-phase flow, consisting of granular magnesium and compressed gas. On the basis of a typical layout of injection systems for the injection of granular magnesium at the pig iron desulphurization plants in the ladles, a laboratory installation has been created that allows the generation of a stable uniform flow of granular magnesium in a stream of compressed air. The stream was passed through a transparent full-scale model of a standard unit for switching the flow into three lances, while the angle of inclination of the device itself, the flow switch, changed. The process was recorded by video. The frame-by-frame analysis of the video image made it possible to study the effect of the existing design of the flow switch at different angles of inclination on the uniformity of the movement of the two-phase flow along the path of the injection system during ladle desulfurization of the molten iron with granular magnesium. The presented studies made it possible to establish the main causes and reveal the mechanism of the generation of pulsations in the cavity of the studied node of the flow switch. It is shown that the volume of the switch cavity contributes to the accumulation of magnesium in it and when tilting more than 22° to the horizon, spontaneous pouring of the accumulated magnesium in the cavity occurs, which is the main reason for the occurrence of pulsations. The recommendations developed on the basis of the research results and their implementation on the existing cast iron desulfurization unit in 100 ton buckets of the new steel plant of the Qingdao Steel Plant (Qingdao, PRC, 2016) made it possible to reduce roughness during processing and ensure stable reagent injection with a double intensity.