Synthesis Gas from Pyrolysed Plastics for Combustion Engine

The article discusses the application of synthesis gas from pyrolysis of plastics in petrol engine. The appropriate experimental measurements were performed on a combustion engine LGW 702 designated for micro-cogeneration unit. The power parameters, economic and internal parameters of the engine were compared to the engine running on the reference fuel - natural gas and synthesis gas. Burning synthesis gas leads to decreased performance by about 5% and to increased mass hourly consumption by 120%. In terms of burning, synthesis gas has similar properties as natural gas. More significant changes are observed in even burning of fuel in consecutive cycles.

Application of Compaction Equations for Powdered Pharmaceutical Materials

The paper is focused on an analysis of the most frequently used compaction equations for powdered materials such as Heckel equation, Kawakita equation and Cooper-Eaton equation. Compacting powdered materials is accompanied by various mechanisms of densification dependent on the properties of the compressed material, which makes the equation more satisfactory for a certain group of materials and for another groups less so, or makes the equation completely unsuitable. To determine the suitability of the equation experimental measurements have to be implemented on an instrumented laboratory press. Then these obtained data are approximated by the specific compaction equation and use the regression analysis to determine the parameters describing the required material or physical properties of the compressed material.

Postural Response Signal Characteristics Identified by Method of Developed Statokinesigram

Human postural system is taken as complex biological system with specific input and output time characteristics, in this study. Evaluation of measured output characteristics is useful in medical diagnostics or in describing postural system disorders. System theory principle provide suitable basis for postural signals analysis. Participating volunteers were instructed to maintain quiet upright stance posture on firm support surface of stabilometric platform for 60s. Postural system actuation was realized by vibration stimuli applied bilaterally on Achilles tendons for 20s. Postural reaction signal, its time profile and static and dynamic characteristics were evaluated by Method of Developed Statokinesigram Trajectory (MDST).

Biomechanics – Elastic Foundation Applied in Modelling of Calcaneal Nails

This paper presents a strength analysis of a calcaneal nail (material Ti6Al4V and stainless steel) which is used to treat complex heel fractures. The application focuses on a unique calcaneal nail, the C-NAIL, produced by Medin a.s. (Nové Město na Moravě, Czech Republic). The paper first presents an analysis of fracture types, treatment methods and loading of the calcaneus. It then presents an analysis of limit conditions and loading. Calculations (displacement and stress) are performed for 6 and 7 fixing screws using FEM (Ansys Workbench 14 software). The calculation involves a new, original application of an elastic foundation, which effectively replaces the complex interaction of the calcaneal nail and the heel bone.

CFD Simulation of a Natural Circulation Helium Loop

The paper deals with a flow in a closed helium loop serving for cooling of a fast reactor. The flow in pipeline branches of the system is simulated by methods of CFD. The purpose is to find exact values of pressure losses, so that heat exchangers could be successfully designed and so that the power available for a loop drive could be optimally utilized. General approach to the simulation is presented, as well as the calculation procedure and achieved results.

Pressure Interaction of Mixing Particulate Material Along the Blade Length

To assess the energy intensity of particulate materials mixing, it is necessary to know the state of stress in the particulate material in front of mixing elements. The theoretical background of this process results from the theory of the equilibrium limit of the particulate material, and this state may by described by Mohr’s circle theory and the Novosad model. Based on the above assumptions, it is possible to derive the pressure distribution along the blade height, but only for an infinitely long blade. A measuring system implemented on the homogenizer blade was constructed to examine the effects of the distribution of the mixed material on the mixing element along its length.

Properties of EN AW-2024 Wrought Aluminum Alloy after Casting with Crystallization under Pressure

Establishing of wrought aluminum alloys casting to manufacture is now a global trend, for example due to lower production costs compare to forging or due to the ability to produce parts with thinner sections and more complex shapes. The aim of using these alloys in the foundry industry is in particular the creation of castings with higher mechanical properties than achieve castings made of standard casting aluminum alloys. Most often are cast wrought aluminum alloys of the 2xxx, 6xxx and 7xxx series. In the experiment, an alloy EN AW-2024 has been cast by modified technology of casting with crystallization under pressure. They were measured basic mechanical properties of the castings in the as-cast state and after heat treatment.

Distribution Characteristics and Compressibility of Agglomerates as a Reflection of Granulation Parameters

Selective adjustment of the properties of particular material agglomeration has its inherent place in the chemical, food, but especially in the pharmaceutical, industry. The requirement to produce an agglomerate with desired particle size at a given strength is often formulated. To create the targeted product, it is necessary to know the process parameters affecting the preparation of its features. This paper deals with survey distribution characteristics and compressibility changes of an agglomerate in dependence on the duration of the granulation process through the usage of the most modern devices working with particulate materials. The investigated product will be prepared for coating granulating disc designed at the Institute of Process Engineering, Faculty of Mechanical Engineering, Slovak University of Technology in Bratislava.

Mathematical Investigation of the Cavitation Phenomenon in the Nozzle with Partially Surface Wetting

Partially surface wetting has a great influence on friction losses in the fluid flow in both the pipeline system and the complex shape of hydraulic elements. In many hydraulic elements (valves, pump impellers), cavitation is generated, which significantly changes the hydraulic flow parameters, so the last part of the article is devoted to the mathematical solution of this phenomena and evaluates the impact of wall wetting on the size and shape of the cavitation area which appears in the nozzle and in small gaps at special conditions. If the cavitation appears e. g. near the wall of pipes, the blades of turbine or a pump, then it destroys the material surface. On the basis of this physical experiment (nozzle), a two-dimensional (2D) mathematical cavitation model of Schnerr-Sauer was made and calculated shape and size of the cavitation region was compared with the experiment. Later this verified model of cavitation was used for cavitation research flow with partial surface wetting. The pressure drop and the size of the cavitation area as it flows from partially surface wetting theory was tested depending on the adhesion coefficient.

Study of Laser Welding of HCT600X Dual Phase Steels

The effects of beam power and welding speed on microstructure, microhardnes and tensile strength of HCT600X laser welded steel sheets were evaluated. The welding parameters influenced both the width and the microstructure of the fusion zone and heat affected zone. The welding process has no effect on tensile strength of joints which achieved the strength of base metal and all joints fractured in the base metal.