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  • Author: Piotr Jankowski x
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Abstract

This paper presents the process of estimating crack propagation within a selected structural component of the PZL-130 Orlik TC-II using a numerical model. The model is based on technical drawings and measurements of the real structure. The proper definition of the geometry, including the location and size of the gap between elements, is significant for mesh generation. During the simulation process the gap is combined node by node. Each time, the strain energy release rate (G) is calculated. The stress intensity factor and geometry correction factor are defined for consecutive crack lengths, and used further on to estimate crack propagation.

Abstract

The paper presents a review of contributions to the scientific discussion on modern methods and tools for public participation in urban planning. This discussion took place in Obrzycko near Poznań, Poland. The meeting was designed to allow for an ample discussion on the themes of public participatory geographic information systems, participatory geographic information systems, volunteered geographic information, citizen science, Geoweb, geographical information and communication technology, Geo-Citizen participation, geo-questionnaire, geo-discussion, GeoParticipation, Geodesign, Big Data and urban planning. Participants in the discussion were scholars from Austria, Brazil, the Czech Republic, Finland, Ireland, Italy, the Netherlands, Poland, the United Kingdom, and the USA. A review of public participation in urban planning shows new developments in concepts and methods rooted in geography, landscape architecture, psychology, and sociology, accompanied by progress in geoinformation and communication technologies. The discussions emphasized that it is extremely important to state the conditions of symmetric cooperation between city authorities, urban planners and public participation representatives, social organizations, as well as residents.

Abstract

Geo-questionnaires have been used in a variety of domains to collect public preferences, behavioural patterns, and spatially-explicit local knowledge, for academic research and environmental and urban planning. This paper provides an overview of the method focusing on the methodical characteristics of geo-questionnaires including software functions, types of collected data, and techniques of data analysis. The paper also discusses broader methodical issues related to the practice of deploying geo-questionnaires such as respondent selection and recruitment, representativeness, and data quality. The discussion of methodical issues is followed by an overview of the recent examples of geo-questionnaire applications in Poland, and the discussion of socio-technical aspects of geo-questionnaire use in spatial planning.

Slaughter Value of Young Polish Black-and-White, White-Backed, Polish Holstein-Friesian and Limousin Bulls Under Semi-Intensive Fattening

The objective of the present study was to compare the slaughter value of young bulls of two breeds included in the genetic resources conservation programme, namely Polish Black-White and White-backed with young Polish Holstein-Friesian (dairy type) and Limousin (beef type) bulls. This is the first study to evaluate the meat performance traits of White-backed cattle in several-centuries history of the breed in Poland. It was determined that populations of White-backed and Polish Black-and-White cattle represent the dual-purpose type desirable in the genetic resources conservation programme. The indices obtained for the analysed traits of slaughter value from young Polish Black-and-White and White-backed bulls were intermediate between Polish Holstein-Friesian (dairy type) and Limousin (beef type), but closer to those of the Polish Holstein-Friesian breed. The analysed muscles of young bulls had a very similar content of basic chemical components. The relatively high amount of proteins (22.85-23.23%) in musculus longissimus lumborum and in musculus semintendinosus (22.43-23.06%) should be emphasized.

Abstract

Health care accessibility can be measured by the number of prospective patients who could reach a medical facility within a prescribed time limit. The representation of health care demand in estimating accessibility is an important consideration since different spatial aggregations of demand have different consequences with regard to accessibility estimates. This article examines the effects of aggregating population demand for primary health care, ranging from census tract to aggregated census block, on estimates of primary health care accessibility. Spatial representations of aggregated demand were incorporated into a location-allocation model in order to determine a measure of accessibility represented by the unmet demand for primary health care services. The model was implemented for the U.S. State of Idaho, based on the allocation of Idaho residents’ demand for primary health care to the state’s existing primary health care facilities. The results confirm a relationship between the level of demand aggregation and the level of potential accessibility. In case of a rural state such as Idaho the relationship is positive; higher levels of aggregation result in higher measures of accessibility.

Abstract

The pollution of water that is used for consumption and in agricultural holdings contributes to an increased mortality rate, inhibition of growth and physiological functions, changes in the DNA (genotoxicity), changes within tissues (cytotoxicity) and organs of individuals who are exposed to chemical components. One of the most dangerous toxin classes which have effect on animals and humans who come into contact with contaminated water is the class of cyanobacterial toxins released by dying cyanobacteria. They contribute to very serious health conditions and also to fatalities. Toxins of this type are relatively difficult to detect on account of their seasonal changeability in blooming. One of the most effective methods of detecting water contamination automatically and continuously is biomonitoring with the use of Dreissena polymorpha mussels.

Abstract

The Su-22 fighter-bomber is a military aircraft used in the Polish Air Force since the mid 1980’s. By the decision of the Polish Ministry of Defense the predicted service life for this type of aircraft will be extended to 3200 flight hours. Due to the fact that some aircraft were nearing the end of the service life guaranteed by the manufacturer, the actual service life, determined based on the flight profile in the Polish Air Force, had to be validated. Consequently, the Full Scale Fatigue Test (FSFT) had to be carried out in order to verify that the required service life was attainable.

This article describes the process of preparation of the load spectra used in the Su-22 FSFT. Due to the fact that the Su-22 has a variable sweep wing the whole test was divided into three Stages (landing, flight and flap loads) carried out at different wing sweep angles (30°/45°/30°).

The spectra were developed using the historical data gathered from Flight Data Recorders (FDR), strain signals acquired during the Operational Load Monitoring program (OLM) and aerodynamic calculations.

Abstract

Processes of the combustion in combustion engines depend on cylinder bore and compression ratio. Compression ratio is a ratio of in-cylinder volume when piston is in bottom dead centre to volume when piston is in top dead centre. Theoretical engine efficiency is increasing together with compression ratio. However, in the real engine there are also other phenomena affecting the efficiency of the engine, which could results in lower performance of engine with higher compression ratio. This study presents knock intensity and performance gain in engine speed function of the 0D-1D engine model with different pistons set. Knock intensity is founded by implementing in combustion process knock sub-model based on Douaud and Eyzat induction time correlation using different pistons geometry. Examined engine model is air restricted Formula Student motorcycle engine. Mounted in intake system, air restrictor decreases knock intensity. Therefore, compression ratio could be increased. It was noticed that bigger bore diameter could reduce knock intensity. Researches realized that bigger bore size could cause performance drop at high rpm when flow is chocked. With changing of compression ratio, performance characteristic changes. Growing compression ratio decrease torque on low engine speed and increase on high engine speed. Further characteristic of the engine could be tuned by matching pistons with modified bore size and compression ratio.

Abstract

This article discusses the use of wavelet decomposition in the diagnostics of vibrometric signals of an engine. Apart from presenting the possibility of using wavelets in diagnostics, the authors take up the subject of the applicability range of processing for stationary signals, which until now has been reserved for non-stationary signals. A unified definition of signal stationarity has been proposed, which is not based on statistics. The authors presented methods of wavelet decomposition of a vibrometric signal of combustion engine vibrations, measured with the use of LDV (Laser Doppler Vibrometry). Laser measurements allows for studying an object without ‘touching’ its housing. Basing on the relative velocity of engine vibrations, the authors indicate how reliable vibrations are in diagnostics. Despite higher costs, this measurement method gives better results (for specific cases) than acoustic studies. Transform – wavelet decomposition is a solution hardly ever used in machine diagnostics; it is more often applied in medicine and image recognition. The authors presented the differences that can be obtained for different levels of decomposition, and also presented the impact on the engine condition assessment through the use of filtering (windowing) the signal before decomposition.

Abstract

This article presents a concept of the full scale fatigue test of a Su-22 fighter bomber. The authors define the general concept and goals of the test as well as the tasks to be accomplished in the preparation stage. The current work status is summarized and future tasks are defined.