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Number of results: 9
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Abstract

The paper presents an empirical comparison of performance of three well known M – estimators (i.e. Huber, Tukey and Hampel’s M – estimators) and also some new ones. The new M – estimators were motivated by weighting functions applied in orthogonal polynomials theory, kernel density estimation as well as one derived from Wigner semicircle probability distribution. M – estimators were used to detect outlying observations in contaminated datasets. Calculations were performed using iteratively reweighted least-squares (IRLS). Since the residual variance (used in covariance matrices construction) is not a robust measure of scale the tests employed also robust measures i.e. interquartile range and normalized median absolute deviation. The methods were tested on a simple leveling network in a large number of variants showing bad and good sides of M – estimation. The new M – estimators have been equipped with theoretical tuning constants to obtain 95% efficiency with respect to the standard normal distribution. The need for data – dependent tuning constants rather than those established theoretically is also pointed out.
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Authors and Affiliations

Marek Banaś
Marcin Ligas
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Abstract

The paper is a summary of a project aimed at identifying and eliminating or minimizing the causes of frequent failures of the Krakow water supply network related to corrosion damage. The paper presents the method of searching for factors responsible for frequent corrosion damage. There were taken into account several factors that may destroy the pipes associated with corrosion processes, such as the composition of the water, aggressiveness of ground, or stray currents. The monitoring method of the corrosion processes applied to observe the condition of the water supply network was discussed. The study showed that the main problem appeared to be stray currents related to the electrical infrastructure widely present in a large city, such as a tram or railway network. To eliminate this threat, a cathodic protection system has been implemented to prevent further failures. There were also demonstrated results of research proving that the applied solutions are effective.
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Bibliography

[1] Zimoch, I. (2008). Reliability Analysis of Water Distribution Subsystem. Journal of KONBiN. 7(4), 307-326.
[2] Jażdżewska, A., Gruszka, M., Mazur, R., Orlikowski, J. & Banaś, J. (2020). Determination of the effect of environmental factors on the corrosion of water distribution system based on analysis of on-line corrosion monitoring results. Archives of Metallurgy and Materials. 65(1), 109-116.
[3] Orlikowski, J., Zielinski, A., Darowicki, K., Krakowiak, S., Zakowski, K., Slepski, P., Jazdzewska, A., Gruszka, M. & J. Banas (2016). Research on causes of corrosion in the municipal water supply system. Case Studies in Construction Materials. 4, 108-115.
[4] Zakowski, K., Darowicki, K., Orlikowski, J., Jazdzewska, A., Krakowiak, S., Gruszka, M., & Banas, J. (2016). Electrolytic corrosion of water pipeline system in the remote distance from stray currents - Case study. Case Studies in Construction Materials. 4, 116-124.
[5] Jazdzewska, A., Darowicki, K., Orlikowski, J., Jazdzewska, A., Krakowiak, S., Zakowski, K., Gruszka, M., & Banas, J. (2016). Critical analysis of laboratory measurements and monitoring system of water-pipe network corrosion-case study. Case Studies in Construction Materials. 4, 102-107.
[6] Loewenthal, R.E., Morrison, I. & Wentzel, M.C. (2004). Control of corrosion and aggression in drinking water systems. Water Science and Technology. 49(2), 9-18. DOI: https://doi.org/10.2166/wst.2004.0075
[7] Booth, G.H., Cooper, A.W., Cooper, P.M. & Wakerley, D.S. (1967). Criteria of Soil Aggressiveness Towards Buried Metals. I. Experimental Methods. British Corrosion Journal. 2(3), 104-108. DOI: https://doi.org/10.1179/000705967798326957
[8] Bertolini, L., Carsana, M. & Pedeferri, P. (2007). Corrosion behaviour of steel in concrete in the presence of stray current. Corrosion Science. 49(3), 1056-1068. DOI: https://doi.org/10.1016/j.corsci.2006.05.048
[9] Chen, Z., Koleva D. & van Breugel, K. (2017). A review on stray current-induced steel corrosion in infrastructure. Corrosion Reviews. 35(6), 397-423. DOI: https://doi.org/10.1515/corrrev-2017-0009
[10] Cui, G., Li, ZL., Yang, C. & Wang, M. (2016). The influence of DC stray current on pipeline corrosion. Petroleum Science. 13(1), 135-145. DOI: https://doi.org/10.1007/s12182-015-0064-3
[11] Memon, M. (2013). Understanding Stray Current Mitigation, Testing and Maintenance on DC Powered Rail Transit Systems. In Proceedings of the 2013 Joint Rail Conference. 2013 Joint Rail Conference, April 15-18, 2013. Knoxville, Tennessee, USA: ASME.
[12] Zhu, Q., Cao, A., Zaifend, W., Song, J. & Shengli, C. (2011). Stray current corrosion in buried pipeline. Anti-Corrosion Methods and Materials. 58(5), 234-237. DOI: https://doi.org/10.1108/00035591111167695
[13] M. Ormellese & A. Brenna (2017). Cathodic Protection and Prevention: Principles, Applications and Monitoring. Reference Module in Chemistry, Molecular Sciences and Chemical Engineering.
[14] Peng, P., Zeng, X., Leng, Y., Yu, K. & Ni, Y. (2020). A New On-line Monitoring Method for Stray Current of DC Metro System. IEEJ Transactions on Electrical and Electronic Engineering. 15(10), 1482-1492.
[15] Yang, L. (2008). Techniques for Corrosion Monitoring. (2nd Ed.). USA: Woodhead Publishing.
[16] Banaś, J., Mazurkiewicz, B., Solarski W., Lelek-Borkowska, U. (2018). Development of the optimal corrosion monitoring system for inner surface of production tubing. In: J. Lubas (Ed.), Development of optimal concepts for the development of unconventional deposits (pp. 78-158). Kraków: Instytut Nafty i Gazu. (in polish)
[17] Scully, J.R. (2000). Polarization Resistance Method for Determination of Instantaneous Corrosion Rates. Corrosion. 56(2), 199-218.
[18] Yang, L., Pan, Y., Dunn, D.S. & Sridhar, N. (2005). RealTime Monitoring of Carbon Steel Corrosion in Crude Oil and Brine Mixtures using Coupled Multielectrode Sensors. In Corrosion 2005, April 2005 (05293). Houston, Texas.
[19] A.S. G01.05, ASTM G1 - 03(2017)e1 Standard Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens, ASTM, 2017, pp. 9.
[20] E.S.E. 12954:2019, General principles of cathodic protection of buried or immersed onshore metallic structures, CEN, 2019, pp. 44.
[21] E.S.E. 50162:2004, Protection against corrosion by stray current from direct current systems, CEN, 2004, pp. 44.
[22] Evitts, R.W. & Kennell, G.F. (2018). Chapter 15 - Cathodic Protection. In M. Kutz (Edt.), Handbook of Environmental Degradation of Materials (3rd Ed.) (pp. 301-321). UK, USA: William Andrew Publishing.
[23] Peabody, A.W. (2018). Control of Pipeline Corrosion. NACE E-Book
[24] Riskin, J. (2008). Chapter 2 - Corrosion and Protection of Underground and Underwater Structures Attacked by Stray Currents. In: J. Riskin (Edt.), Electrocorrosion and Protection of Metals (pp. 23-35). Amsterdam: Elsevier.
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Authors and Affiliations

U. Lelek-Borkowska
1
M. Gruszka
2
J. Banaś
1

  1. AGH University of Science and Technology, Reymonta 23, 30-059 Krakow, Poland
  2. WMK S.A., Senatorska 1, 30-106 Krakow, Poland
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Abstract

Corrosion of water distribution system is a significant issue causing problems with quality, safety and continuity of distribution. The changes of corrosion rates of the water distribution systems in Cracow made of carbon steel were investigated by analysis of online corrosion monitoring system results. Corrosion rates were determined using the linear polarization method. The impact of rain, temperatures, conductivity, dissolved oxygen content on corrosion rate were characterized. The corrosivity of different water sources like mountain water, underground water or river water were indicated. The possible actions for reducing corrosion losses were characterized. Results show that pollution of the environment in the form of acid rain and runoff from agriculture as well as the type of the source water has significant influence on corrosion of water distribution system. Corrosion monitoring system gives possibility of controlling corrosion rate by mixing waters from different sources in the way to obtain less corrosive mixture (see Fig. 8).

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Authors and Affiliations

A. Jażdżewska
M. Gruszka
R. Mazur
J. Orlikowski
J. Banaś
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Abstract

Temporomandibular disorders (TMD) encompass a diverse group of abnormalities in the functioning of the masticatory muscles, temporomandibular joints, and surrounding structures within the facial skull. One of the important etiological factors, contributing to the development of TMD are psychoemotional disorders, which include: depression, dysthymia, personality disorders, panic attacks as well as states and anxiety neuroses.
The aim of the study was to carry out a retrospective evaluation of the occurrence of psychoemotional disorders reported in the application form of medical interview of patients treated at the Consulting Room of Temporomandibular Disorders in Dental Institute (University Dental Clinic) for TMD.
The research material consisted of a subjective survey according to the protocol of the RDC/TMD questionnaire, axis II, of the 360 patients (224 women, 136 men), aged 19 to 43 who came to the University Dental Clinic in Krakow due to TMD management.
Result: The results of the conducted studies indicate the common occurrence of emotional disorders in the group of patients treated for TMD, both in the group of muscular and joint form of dysfunctions. The most often the patients selected: loss of sexual interest or pleasure, crying easily, feeling lonely, indifference to every-thing and feeling of worthlessness. These aspects show a significant influence of emotional factors on TMD.
Conclusion: The results of the conducted research indicate a significant frequencies of psychological and emotional disturbances reported in a survey among patients with TMD. Key
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Authors and Affiliations

Małgorzata Pihut
1
Magdalena Krasińska-Mazur
1
Joanna Biegańska-Banaś
2
Andrzej Gala
1

  1. Consulting Room of Temporomandibular, Disorders, Dental Institute, Prosthodontics Department, Jagiellonian University Medical College, Kraków, Poland
  2. Institute of Nursing and Midwifery, Department of Health Psychology, Jagiellonian University Medical College, Kraków, Poland
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Abstract

Objective: The goal of this contribution is to present and familiarize the medical community with the method for the assessment of trace and essentials elements in prostate tissue sections. Materials and methods: X-ray fl uorescence based technique (namely Synchrotron Induced X-ray Emission (SRIXE)) is described in terms of methodology, sample preparation and the evaluation of the recorded results (spectral data sets). Materials for the samples were collected from the patients underwent radical prostatectomy due to Adenocarcinoma prostatae. Specimens were freeze-dried, cut by microtome (to the thickness of 15 μm), one slice was placed on Mylar foil (for SRIXE measurements) and adjacent one on microscopic glass (for histopathological assessment). Results: Results presented here show the usability of SRIXE method for the evaluation of concentration of trace and essential elements in prostate tissue sections with the spatial resolution better than 15 microns. Discussion: Histopathological analysis of samples, which is only focused on morphological features, is unable to reveal information about changes in biochemical signature of tissues aff ected by the illness. SRIXE is a powerful and promising technique to analyse even very low concentrations of selected elements at the cellular level without any labelling or separating procedures. Obtained results may be correlated with classic histopathological assessment allowing for drawing conclusions on the changes in certain elements concentrations with the progression of disease. Moreover, mentioned in this work analysis, can be performed for any type of biological tissues.
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Authors and Affiliations

Bohdan Pawlicki
Aleksandra Pawlicka
Agnieszka Banas
Krzysztof Banas
Mariusz Gajda
Grzegorz Dyduch
Wojciech M. Kwiatek
Mark B.H. Breese

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