Technical Transactions. Iss. 9

Technical Transactions. Iss. 9

Type: Collection of magazine numbers
Release date

Collection items (16)


Computed tomography as a quality control technique in the 3D modelling of injection - moulded car system components

Barciewicz, Monika, Ryniewicz, Andrzej
Article
2018
This paper presents the sophisticated capabilities of industrial computed tomography (CT) in the development and 3D modelling process of new car system components. Usually, the process of the development of new car components takes three to five years. At each development process stage, quality control is crucial to catch all internal and external defects. This is particularly important with regard to components made using an injection-moulding process. Computed tomography as a non-destructive testing method is an excellent tool for controlling and improving both the manufacturing process and the 3D modelling of tested components. All analyses performed with use of CT are essential for meeting customer requirements. This paper shows how industrial computed tomography can control the quality of the car components development process.

The application of computed tomography in the automotive world – how industrial CT works

Barciewicz, Monika, Ryniewicz, Andrzej
Article
2018
This paper shows how industrial computed tomography (CT) works, its benefits and where it can be used in automotive world. As a non-destructive quality control technique (NDT), CT allows not only the measurement and evaluation of external and internal geometry, but is also useful for making reports with a visualisation of an entire component, e.g. a map of shape deviation and internal structural defects.

Measurements and simulation of CO2 concentration in a bedroom of a passive house

Szczepanik-Ścisło, Nina, Flaga-Maryańczyk, Agnieszka
Article
2018
This paper presents the results of the measurements and simulation of carbon dioxide concentration, as an indicator of indoor air quality, inside the master bedroom of an inhabited passive house. The measurements were taken in the autumn for a period of ten days. A series of sensors placed inside of the test object wirelessly measured the contaminant concentration every thirty seconds. The measurements were taken continuously in real time, when the occupants freely used the household. The contaminant concentration shows the impact of their activity on the air quality, as they were the only indoor air source of CO2. During the measurements, the ventilation system that the house was equipped with was manually controlled by the users according to their daily routine. Simulations were performed to determine if it was possible to recreate the measured conditions within the bedroom of the passive house. The chosen program was the CONTAM software application, a tool designed for indoor air quality and ventilation analysis, developed by NIST.

The quality of coal in Poland, Russia and Ukraine and its effect on dust emission into the atmosphere during combustion

Małkowski, Piotr, Tymoshenko, Ievgen
Article
2018
This paper presents the characteristics of coal quality in Poland as well in Ukraine and Russia – the two largest import sources. The analysis was carried out on the energy coal market for domestic use in all three countries from the perspective of the supply, demand and current prices. Thereupon was the analysis of the potential dust emission during combustion that results from the natural ash content in the coal, and with consideration to the efficiency of the furnace and the combustion method. The results of the analysis and the computation show that there are no significant differences in the quality of the coal from Poland, Ukraine or Russia. However, the important factor is the calorific value and, closely related to it, the content of non-combustible solids and dust emission. The analysis of dust emission proves that the impact on the environment can be significantly reduced by burning coals with a minimum calorific value of 27,000 kJ/kg.

Adaptation of coutyards into covered and glazed atriums and its impact on the level of acoustic comfort inside – case study

Ziarko, Bartłomiej
Article
2018
Increasingly popular, in the area of modernization or revitalization of historic buildings, is the creation of a roof that is often fully glazed over the inner courtyard, thus creating a new spacious interior capable of performing many functions. The acoustics evaluation undertaken in this article was carried out on the basis of measurements and simulation of reverberation time in The Home Army Museum building in Cracow.

Reduction of acoustic cavitation noise emission with textile materials

Nering, Konrad, Nering, Krzysztof
Article
2018
This article presents an examination of the acoustic noise level reduction in piping applications. Hydraulic cavitation is the source of the noise. In order to determine the noise level drop for the insulating material arranged around the pipe – cylindrical geometry – the acoustic spectrum was measured in the range of audible frequencies. Measurements were made for textile materials stacked with varying amounts of layers around the source of noise. There was a decrease in the noise level characteristics for mass law. An empirical formula describing the relative noise reduction for the materials under study was proposed.

Usage of a zero-sum differential game in the optimal control of an object described by a nonlinear model

Mikulski, Leszek, Kropiowska, Dorota
Article
2018
This article presents the usage of a zero-sum differential game to control a nonlinear object, which, in the analysed problem, was a mathematical pendulum. The obtained control was optimal with regard to adopted quality indicator for the worst interference. The two-point boundary value problem was solved numerically by means of the Dircol software application. Numerical solutions, meeting all the necessary optimality conditions, were obtained for different values of the rough parameter and for different values of damping.

The reliability of masonry structures – evaluation methods for historical buildings

Domański, Tomasz, Matysek, Piotr
Article
2018
In this paper, selected issues regarding the assessment of the reliability of masonry structures in existing buildings, including historical buildings, are presented. The specifics of diagnostics and computational analysis of these types of objects are highlighted. Methods of determining the masonry compressive strength in existing structures while taking into account the reliability theory are given. A combination of nondestructive and destructive tests is proposed as the basis for determining the masonry strength parameters. Practical solutions for determination of design masonry strength were given which can be used in assessing the safety of massive brick walls and pillars constituting important structural elements of existing masonry buildings.

Determinants of land developers’ activity in Poland

Belniak, Stanisław, Kania, Katarzyna
Article
2018
The proper use of space, particularly in urban areas, has become very important. Land developers are focused on activities which increase the value of land by preparing it for investment (the purchase of land, transforming it into the building area, merging or division of land into smaller parcels, utilities, and the final sale to other developers). In this article, land development activity is also considered as part of the development process. The aim of this study is to identify the factors that determine the manner of activities related to the procurement and preparation of land for construction by developers. The research is an important step towards the creation of the concept of land developers’ activity in Poland.

Parameters of the Carslaw-Jaeger equation describing the temperature distribution in the ground

Larwa, Barbara, Gwadera, Monika, Kicińska, Izabela, Kupiec, Krzysztof
Article
2018
The ground temperature changes with depth and time. Time variability is considered as a harmonic function. The equation describing changes of the ground temperature contains four parameters: the average annual temperature of the surface of the ground, the annual amplitude of the temperature of the ground surface as well as the phase angle of the temperature and thermal diffusivity of the ground. Based on the results of the measurements presented in the literature, the parameters of the equation using the combined method on the basis of linear regression, described in the literature, were determined. This method, however, leads to an ambiguous value of the thermal diffusivity. It was found that the nonlinear regression method gives much better results, leading to obtaining precise and unambiguous values of all parameters of the equation.