The problems related to construction production are multi-faceted and complex. This has promoted the search for different methods/approaches for analizing the data which supports the decision-making process in the construction industry. In the article the authors focus their attention on well-known methods and tools, and on some new approaches to solving decision-making problems. The aim of the article is to analyze the methods used to analyse data in a construction company, convey their advantages and disadvantages, and specify the degree of efficiency in the discussed area.
During the planning and controlling of the construction process, most attention is focu sed on risk analysis, especially in the context of final costs and deadlines of the investment. In this analysis, the primary and most significant concern is the proper identification and quantification of events, which on a certain level of probability may affect the development process. This paper presents the result of a risk analysis for a particular building object, made after completion of the investment and accepting it for use. Knowledge of the planned values and the actual investment process allowed for the identification of the events and their effects that in this case have significantly disrupted the investment process. The limited total cost of the investment project in question had a considerable impact on the progress of the project execution. Despite three transitions of administrative procedures, the opening date of the shopping centre was delayed by only three weeks.
Many wire products (e.g. nets) are made from galvanized material. The hot dip galvanizing process gives the possibility of applying in a respectively thick coat of zinc (also depending on the time of staying wires in the bath) which provides the protection of the product against corrosion. In the available literature there were no research concerned with the influence of hot dip galvanizing process on the mechanical properties TRIP structure steel wires. Therefore, an experiment was carried out in laboratory conditions allowing the determination of the influence of hot dip galvanizing process parameters on the mechanical properties (tensile strength UST and yield strength YS) of TRIP steel wires as well as on the amount of retained austenite in their structure. It has been stated that the hot galvanizing process of TRIP steel wires influences, proportionally to the time of staying wires in zinc bath, on their plastic properties (the increase in yield strength YS) as well as the decrease in the amount of retained austenite in their structure. Such a phenomenon can be caused by stresses responsible for rapid heating of the wire put in the zinc bath in temperature of 450°C and by the strengthening of the materials resulting from the transformation of retained austenite.
The article raised issues related to the design and execution of low-energy objects in Polish conditions. Based on the designed single-family house, adapted to the requirements of the National Fund for Environmental Protection and Water Management ("NF40" standard), the tools to assist investment decisions by investors were shown. An economic analysis and a multi-criteria analysis were performed using AHP method which had provided an answer to the question whether it is worthwhile to bear higher investment costs in order to adjust to the standards of energy-efficient buildings that fulfil a minimal energy consumption's requirements contained in Polish law. In addition, the variant of object that had optimal characteristics due to the different preferences of investors was indicated. This paper includes analysis and observations on the attempts to unify that part of the building sector, which so far is considered to be personalized, and objects in accordance with the corresponding idea are designed as "custom-made".
The main aim of this work is to study the thermal efficiency of a new type of a static mixer and to analyse the flow and temperature patterns and heat transfer efficiency. The measurements were carried out for the static mixer equipped with a new mixing insert. The heat transfer enhancement was determined by measuring the temperature profiles on each side of the heating pipe as well as the temperature field inside the static mixer. All experiments were carried out with varying operating parameters for four liquids: water, glycerol, transformer oil and an aqueous solution of molasses. Numerical CFD simulations were carried out using the two-equation turbulence k-ω model, provided by ANSYS Workbench 14.5 software. The proposed CFD model was validated by comparing the predicted numerical results against experimental thermal database obtained from the investigations. Local and global convective heat transfer coefficients and Nusselt numbers were detrmined. The relationship between heat transfer process and hydrodynamics in the static mixer was also presented. Moreover, a comparison of the thermal performance between the tested static mixer and a conventional empty tube was carried out. The relative enhancement of heat transfer was characterised by the rate of relative heat transfer intensification.
The article is a case study of the steel milling ring casting of about 6 tonnes net weight. The casting has been cast in the steel foundry the authors have been cooperating with. The aim was to analyse the influence of the shape of the chills and the material which was used to make them on the casting crystallization process. To optimally design the chills the set of the computer simulation has been carried out with 3 chills’ shape versions and 3 material’s versions and the results have been compared with the technology being in use (no chills). The proposed chills were of different thermal conductivity from low to high. Their shapes were obviously dependant on the adjacent casting surface geometry but were the result of the attempt to optimise their effect with the minimum weight, too. The chills working efficiency was analysed jointly with the previously designed top feeders system. The following parameters have been chosen to compare their effectiveness and the crystallization process: time to complete solidification and so-called fed volume describing the casting feeding efficiency. The computer simulations have been carried out with use of MagmaSoft v. 5.2 software. Finally, the optimisation has led to 15% better steel yield thanks to 60% top feeders weight reduction and 40% shorter solidification time. The steel ring cast with use of such technology fulfil all quality criteria.
This work presents the results of the research of the effect of the inoculant Emgesal Flux 5 on the microstructure of the magnesium alloy AZ91. The concentration of the inoculant was increased in samples in the range from 0.1% to 0.6%. The thermal processes were examined with the use of Derivative and Thermal Analysis (DTA). During the examination, the DTA samplers were preheated up to 180 °C. A particular attention was paid to finding the optimum amount of inoculant, which would cause fragmentation of the microstructure. The concentration of each element was verified by means of a spark spectrometer. In addition, the microstructures of the samples were examined with the use of an optical microscope, and an image analysis with a statistical analysis using the NIS–Elements program were carried out. Those analyses aimed at examining the differences between the grain diameters of phase αMg and eutectic αMg+γ(Mg17Al12) in the prepared samples as well as the average size of each type of grain by way of measuring their perimeters. This paper is an introduction to a further research of grain refinement in magnesium alloys, especially AZ91. Another purpose of this research is to achieve better microstructure fragmentation of magnesium alloys without the related changes of the chemical composition, which should improve the mechanical properties.
The field of academic research on corporate sustainability management has gained significant
sophistication since the economic growth has been associated with innovation. In this paper,
we are to show our research project that aims to build an artificial intelligence-based neurofuzzy
inference system to be able to approximate company’s innovation performance, thus
the sustainability innovation potential. For this we used an empirical sample of Hungarian
processing industry’s large companies and built an adaptive neuro fuzzy inference system.
Technological development offers a wide range of new possibilities for implementation of
production processes. Continual production development is the main key to success and
competitiveness improvement, labour productivity and image-building for all manufacturing
companies. The article deals with designing of new workplace with implementation and
utilization of automated robot for faster and safer handling of cast stock. The new layout
of workplace is created in software Process Simulate.
The attempt was made to describe the dynamics of water masses in the southern part of the Drake Passage and the Bransfield Strait in the time period from December 1983 to January 1984. The dynamic topography at the surface (referred to 500 dbar surface) allowed to define the eastward flow of water in the Bransfield Strait and to observe, in the same region, the presence of a rather weak counter-current of the Weddell Sea origin. In the Drake Passage, a general north-eastern direction of water flow of the Bellingshausen Sea was found. In the Bransfield Strait, as well as in the Drake Passage, the relative velocities of geostrophic flow were low: 0.22 and 0.06 m s-1 respectively. The analysis of Rossby and eddy numbers and Rossby radius made it possible to regionalize the dynamic phenomena but could not be fully used for their classification.
Business Process Modelling Notation (BPMN) is a visual specification language without well-defined concepts for equivalences. This necessitates the establishment of fundamental notions that underpin the equivalences of BPMN processes. The main body of the paper is centered around the principle of substitutibility in which different types of equivalences of BPMN processes are formally described. Additionally, these results provide a basis for defining the behavioural equivalence of BPMN models. Our research investigation contributes to the field of business process management by developing a tight con-nection between BPMN and its associated equivalence notions.
This paper presents possibilities for of numerical modelling of biomass combustion in a commercially available boiler. A sample of biomass was tested with respect to its physical and chemical properties. Thermogravimetry studies of biomass were carried out. Computer simulation makes it possible to analyse complex phenomena which are otherwise difficult to observe. The aim of this work was to model biomass combustion to predict the amount of pollutants generated (NOx, CO, SO2) in the exhaust gases coming out from boilers The calculations were made using the CHEMKIN program. Results of calculations were performed taking into account the influence of temperature, pressure and residence time.
The article is focused onthe energetical balance of a technical system for the conversion of crushed tyres by pyrolysis. Process temperatures were set in the range from 500 to 650°C. Mass input of the material was 30 kg per hour. The aim of the article is to answer the following questions as regards the individual products: Under which process conditions can the highest quality of the individual products related to energy be reached? How does the thermal efficiency of the system change in reaction to various conditions of the process?
On the basis of the experimental measurements and calculations, apart from other things, it was discovered that the pyrolysis liquid reaches the highest energetic value, i.e. 42.7 MJ.kg-1, out of all the individual products of the pyrolysis process. Generated pyrolysis gas disposes of the highest lower calorific value 37.1 MJ.kg-1 and the pyrolysis coke disposes of the maximum 30.9 MJ kg-1. From the energetic balance, the thermal efficiency of the experimental unit under the stated operational modes ranging from about 52 % to 56 % has been estimated. Individual findings are elaborated on detail in the article.