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1

Model based compensation of geometrical deviations due to process forces

Denkena B., Dahlmann D., Peters R., Witt M.

Journal of Machine Engineering

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2017

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Vol. 17, No. 1

5--16

EN

Machining accuracy can be considerably affected by deflections of machine tool components and the workpiece. This work presents a new approach for real-time deflection compensation, based on control integrated models. A real-time material removal rate (MRR) simulation determines the depth of cut which is used for process force calculation by Kienzle-Equations. Machine tool and workpiece deflections are then derived from a mechanical model using the calculated process forces. For this purpose, control based signals are used as model inputs. The total deviation is sent to the position controller as a setpoint offset. A dynamometer was applied to validate the simulated process forces. The presented approach was validated for cylindrical turning operations on chucked steel shafts. The experiments were carried out on a high-precision slant bed lathe. The results show, that geometrical errors could be reduced by more than 70% on average.

2

Partition of pentachlorophenol (PCP) into particulate and dissolved phases in the waters of the Vistula River mouth at the Gulf of Gdańsk

Kobusińska M. E., Witt M., Lewandowski K., Niemirycz E.

Oceanological and Hydrobiological Studies

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2016

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Vol. 45, No. 2

172--181

EN

The Vistula River plays an important role in the supply of autochthonous and allochthonous material to the Gulf of Gdańsk. The suspended particulate matter (SPM) of fluvial origin is considered to constitute a specific sorbent for halogenated organic compounds due to their lipophilic characteristics and relative solubility. Because there are many factors affecting the input of SPM into the estuarine environment of the Gulf of Gdańsk, e.g. hydrological characteristics of the Vistula River, it became necessary to verify whether the same processes may affect a discharge of organic contaminants. The study presents an approach to the assessment of temporal trends in SPM concentration in the Vistula River discharged into the Gulf of Gdańsk as well as the analysis of pentachlorophenol (PCP), a commonly used agricultural biocide, a precursor of dioxins in either dissolved or particulate phases in the river (the Vistula River) and sea waters (the Gulf of Gdańsk). The study revealed that the hydrological characteristics appear to influence a load of SPM. However, the discharge of PCP is additionally related to the environmental conditions, physicochemical properties of the compound and the sorbent, affecting the partitioning of PCP into dissolved and particulate phases.

3

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and pentachlorophenol (PCP) in bottom sediments of the Port of Gdansk

Lewandowski K., Witt M., Kobusińska M., Niemirycz E.

Oceanological and Hydrobiological Studies

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2014

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Vol. 43, No. 3

312--323

EN

Combustion processes are considered to be the main source of the dioxin emission in the Baltic region. Pentachlorophenol (PCP) and its derivatives, pentachlorophenyl laurate (PCPL) and sodium pentachlorophenate (NaPCP) are known as precursors of dioxins. The research was conducted to obtain the first data on the concentration of PCDD/Fs and PCP in the bottom sediments of the Port of Gdansk. Toxicity (the Microtox® test) as well as several sediment parameters have been examined. In the surface layer of bottom sediments from the Port of Gdansk, all congeners of PCDD/Fs have been detected using GC-MS/MS. The highest concentration was obtained for OCDD (224.0–271.0 pg g−1 d.w.) and HpCDD (51.0–36.0 pg g−1 d.w.). The content of ΣPCDDs prevailed over ΣPCDFs. This may indicate that anthropogenic pollution from the land-based thermal sources has the strongest impact on the concentration of dioxins in the port sediments. The concentration of 17 dioxin congeners (WHO-TEQ) did not exceed the probable effect level (PEL) of 21.5 pg TEQ g−1 d.w. The concentration of PCP ranged from bellow the LOD (< 0.85 ng g−1 d.w.) to 12.4 ng g−1 d.w. The positive correlation between toxicity and physico-chemical properties of the analyzed bottom sediments confirms that these parameters are important in terms of environment contamination.

4

Geostatistical methods for estimation of toxicity of marine bottom sediments based on the Gdańsk Basin area

Witt M., Kobusińska M., Maciak J., Niemirycz E.

Oceanological and Hydrobiological Studies

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2014

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Vol. 43, No. 3

247--256

EN

Toxicity assessment of environmental compartments, in particular sediments as a highly complex matrix, provides a more direct way to assess potential adverse effects of pollutants present in a sample in contrast to chemical analysis estimating only a quantitative level of xenobiotics. Interactions between chemicals, formations of derivatives and the influence of chemical properties of sediments such as the organic matter content causing the intensified sorption of hydrophobic pollutants suggest that a traditional approach to the sediment quality, based only on chemical analysis may be insufficient. The presented study describes the vertical and horizontal variability of toxicity of Gdańsk Basin sediments. Based on 128 surface sediments samples and using geostatistical methods, a prediction map for the EC50 parameter was created. This allowed the evaluation of the toxicity of the surface sediment layer at any selected point of the study area. The applied analysis can be functional for many other locations worldwide. In the present study, the hypothesis about the location of toxic sediments in the vicinity of Gdańsk Deep, outer Puck Bay and close to Vistula River mouth was further confirmed.

5

Eurammon: Węglowodory – czynniki chłodnicze neutralne wobec klimatu

Witt M.

Technika Chłodnicza i Klimatyzacyjna

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2010

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nr 3

106-108

PL

W publikacji zwrócono uwagę na istotne zalety dwóch naturalnych czynników chłodniczych będących węglowodorami, a są to propan (R 290) i propylen (R 1270). Przedstawiono przykłady ich praktycznego wykorzystania w różnych aplikacjach. Pierwsza z nich, to klimatyzatory indywidualne z propanem produkowane przez chińską firmę Gree Electric Appliances. Innym przykładem zastosowania tego czynnika jest chłodnia w Chartham koło Canterbury w Anglii. Trzeci przykład, to zastosowanie propylenu w instalacji do wychładzania specjalnych zbiorników w koncernie farmaceutycznym Roche

EN

Important advantages of two hydrocarbons - propane (R290) and propylene (R 1270) are described. Examples of their use in individual air conditioners, in cold storage rooms and in pharmacy industry are given

6

Naturalne czynniki chłodnicze

Witt M.

Chłodnictwo i Klimatyzacja

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2010

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nr 10

20-21

PL

Decyzja o wyborze czynnika obiegowego stosowanego w urządzeniach chłodniczych lub klimatyzacyjnych oparta jest na podstawowych wskaźnikach opisujących bezpieczeństwo jego wykorzystania, koszty produkcji oraz wpływ na środowisko. Jednak na tle stale rosnących cen nośników energii, energochłonność urządzeń zaczyna odgrywać coraz większą rolę. Idealny czynnik chłodniczy powinien mieć bardzo dobre własności termodynamiczne, wysoką stabilność chemiczną oraz dobre parametry fizyczne. Ponadto powinien w minimalnym stopniu degradować środowisko naturalne, być możliwie tanim i łatwo dostępnym.

7

Obecne osiągnięcia w chłodzeniu amoniakiem

Witt M.

Chłodnictwo i Klimatyzacja

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2008

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nr 11

28-29