The Influence of the Initial State on Microstructure and Mechanical Properties of Hydrostatically Extruded Titanium

score: 0collation: 191-19

New Method of Measurements of Magnetic Characteristics in Two Perpendicular Axis of Amorphous Ribbon

score: 5collation: 378-38

Grain Boundary Structure in Titanium Diboride

score: 0collation: 129-13

Solid Oxide Electrolysis Cell Systems — Variant Analysis of the Structures and Parameters

abstractEN: The paper presents a variant analysis of the structure of SOEC systems. The main parameters of such systems are indicated and commented. The comparison of various configurations is shown in terms of efficiency obtained. High efficiency (70%) hydrogen generation seems possible with systems like these.score: 7collation: 106-11

Seasonal Thermal Energy Storage - A Size Selection

abstractEN: The paper presents a theoretical investigation of using a Seasonal Thermal Energy Storage facility (STES) to cover the heat demand of a complex of four buildings. The STES is placed in the ground and connected to both the local district heating network and solar panels. A number of scenarios were investigated to find an adequate size of the STES (tank size and solar panel area.) The results obtained show that the use of a STES could reduce heat consumption by 22100% depending on the architecture solution chosen.score: 7collation: 270-27

Empirical Mode Decomposition of vibration signal for detection of local disturbances in planetary gearbox used in heavy machinery system

abstractEN: In rotating machinery, the detection of local damage is one of the most important issues. This kind of change of technical condition produce local disturbance according to temporal (local) change of stiffness of kinematic pair (tooth-tooth contact, rolling element-outer/inner race etc). In many practical, i.e. industrial cases, vibration signature of such change is weak in sense of produced energy, so consequently, completely masked by other vibration sources in machine. The general concept of signal processing for local damage detection is to use so called signal enhancement, i.e. a kind of tool that may improve signal to noise ratio. One may find many approaches used in the literature. Most of them use signal filtering (classical, adaptive and optimal filters), decomposition (wavelets) or extraction (blind source separation). Empirical Mode Decomposition (EMD) is one of such techniques that can be used with signal decomposition problem. In this paper, EMD will be used for vibration signal decomposition in order to extract information about local perturbation of arm (carrier) in planetary gearbox used in heavy mining machine, i.e. bucket wheel excavator. As a result of application of EMD, one may obtain several time series with different properties of sub-signal. Due to predefined task, namely local disturbance detection, several criteria have been investigated in order to select the most informative empirical mode. First criterion was kurtosis calculated for every mode with very simple decision rule (max kurtosis is the best). It was found that such approach is not optimal due to some random impulses that are not related to damage. To improve results, it is proposed to combine envelope spectrum and kurtosis. If envelope spectrum contains family of components related to arm (carrier) shaft frequency and signal is spiky (kurtosis is high) result of EMD for given mode is optimal in sense of carried information. However, in this approach decision was made based on visual inspection of the envelope spectra of each mode, which is non-effective way. Finally two parameters have been proposed: 1) Pearson correlation coefficient of an empirical mode and the empirically determined local mean of original signal; 2) a relative power of an empirical mode.score: 15collation: 109-11

Declarative Approach to AGVS Modeling and Cyclic Scheduling

abstractEN: The paper presents constraint satisfaction problem driven approach to analytical solution of the cyclic scheduling problem in the Flexible Manufacturing System (FMS) producing multi-type parts where for material handling are used the Automated Guide Vehicles Systems (AGVS). Finding the conditions guaranteeing the AGVs deadlock-free and collision-free movement policy is the aim of our researches. The AGVs co-sharing the common parts of the transportation route while executing repetitive processes, i.e. being assigned to AGVs passing along machines in a cyclic way, can be modeled in terms of Cyclic Concurrent Process Systems (CCPS). Schedulability analysis for a given CCPS answers the question whether a cyclic schedule exists or not. The paper suggests approach for schedulability analysis of multimodal processes representing real manufacturing employing the declarative modeling.score: 0collation: 573-57

Composition – property relations in shear thickening fluids

score: 5collation: 91-9

Magnetic and Martensitic Transformations in Ni46Mn41.5-xFexSn12.5 Melt Spun Ribbons

score: 5collation: 23-3

Use of polishing alumina as flame retardant in orthophthalic polyester resin matrix composites

abstractEN: Within the field of Civil Engineering Materials, a use for a range of industrial waste products as substitutes has been found which are as effective as standard construction materials but which have the bonus of providing an ecologically sound alternative for materials that wouldotherwise become an environmental concern. The use of waste materials in polymer composites is a prime example of this practice. These composites display excellent mechanical properties but need to be adapted to control the combustibility properties. This paper reports on a study aimed to produce polymer concrete composites using waste alumina from metallurgic industrial processing.The composites have an ortophtalic polyester resin as a binder, river sand as aggregate and fly ashas filler. Two kinds of flame retardants were used: the first is a residue, polishing alumina and thesecond a other virgin commercial alumina which were used in four different percentages in relation to the mass of the resin. The samples were subjected to flexural strength testing, temperature changes of 125, 225 and 325°C and porosity by mercury addition.score: 7collation: 209-21