Navigational safety of inland vessels in the Międzyodrze and Szczeciński Węzeł Wodny area

On the basis of available literaturę a profile was madę of hydrometeoro-logical conditions dangerous for navigation in the Polish Coastal zonę of the Baltic There have been discussed stormy winds, seaway. fog, ice conditions. atmospheric precipitation and their effect on the accident ratę of fishing boats

Podano wyniki oceny procesu eksploatacji silników napędu prądnic typu 6AL20/24 trzech typów masowców. Wyodrębniono 4 stany procesu eksploatacji i skupiono się na czasie użytkowania efektywnego. Dla tego stanu wyznaczono wybrane wskaźniki takie jak: średni czas użytkowania efektywnego w ciągu doby. miesiąca, roku oraz wskaźnik użytkowania efektywnego.

Oddajemy w ręce czytelnika pierwszy numer Zeszytów Naukowych Wyższej Szkoły Morskiej w Szczecinie. W wydaniu tym zamieszczono szereg prac naukowych z różnych dziedzin związanych z gospodarką morską, o różnym zakresie badań, i formie opracowania zgodnie z kierunkiem działalności uczelni. Jest to tylko niepełny przegląd dokonanych osiągnięć naukowych w pierwszym okresie istnienia WSM w Szczecinie. W przyszłości wydawane będą oddzielne Zeszyty Naukowe uprofilowane dla zagadnień nautycznych, połowowych, mechaniki okrętowej oraz dyscyplin podstawowych. Wydanie pierwszego z Zeszytów Naukowych zbiegło się z Rokiem Nauki Polskiej i jest wyrazem zamierzeń intensywnego rozwoju badań naukowych Wyższej Szkoły Morskiej w Szczecinie. Redakcja żywi nadzieje, że ten pierwszy krok naszej uczelni w prezentacji dorobku naukowego zostanie życzliwie przyjęty przez Czytelników.

When hot exhaust gas is mixed with inlet air, the charge to a diesel engine is modi-fied in different ways: the charge temperature increases, the total charge mass is re-duced and the charge composition changes. This paper is concerned with the residual gas fraction that is usually determined by straight CO2 measurement in a sample of gas extracted from a cylinder during the compression stroke. A general zero-dimensional model for calculating the residual gas fraction in reciprocating internal combustion engines has been formulated. The model accounts for both the trapped gas in the cylin-der at top dead center and the back-flow of exhaust gas into the cylinder during the valve overlap period. The effect of EGR introduction has been discussed.

The paper presents selected results of torsional vibration measurements of propulsion shafts driven by a medium-speed Sulzer-made marine diesel engine of AL type. The research aimed to find out wheter it is possible to diagnose failures of the fuel feed system by means of torsional vibration spectral analysis. The research resulted in the author's proposal of a new diagnostic measure.

The paper contains a formal description of ship propulsion system operation process. The model of the process is presented in the form of two-dimensional stochastic process of which coordinates are semi-MArkov processes of the final states set. The former process describes the process of changes in technical states of ship propulsion systems, the latter - the process of changes in their operating states a monovariate model of ship propulsion systems operation process has also been proposed.

Erosion wear of a fan rotor blade is analysed in the paper. The calculated values of contact stresses show than mechanisms of destruction my exist during: !) perpendicular impact, 2) slip with participation of fiction forces. Materials used in the paper in conditions of stream-abrasive erosion should have potentially high tield field and low. Young's modulus.

This research focused on the examination of the microstructure and useful proper-ties of martensitic steel H9S2 subjected to plasma nitriding processes. The influence of process parameters such as the temperature and gas composition on micro-hardness, corrosion and wear was investigated. The application of plasma nitriding processes significantly increases the micro-hardness and wear resistance.

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This paper presents the influence of a change in the number of rings on blow-by in-to the crankcase of a single-cylinder engine SB-3.1. Blow-by-speed characteristics were made for idle running.

The factor of thermal efficiency, used for the assessement of the use of heat in the diesel engine working cycles, has been based on the the first law of thermodynamics only. This paper indicates the fact that to achieve more comprehensive thermodynamic analyses it is necessary to use factors based on the two laws of thermodynamics. One such factor herein proposed is the exoergic efficiency. The method for the determination of this factor for the main engine is presented. Original relations involving the exoergic efficiency are set out. The factor depends on the ambient temperature.

The paper presents the results of acoustic emission signals application for diagnos-ing defects detecting signal sources in the fuel injection system of marine diesel engines. Changes of acoustic emission signals are sensitive to the working of the injection pump and the condition of injectors. The emitted signals are dependent on their technical con-dition.

For many years the analysis of concentration residual hydrocarbon and oil in sam-ples of water and soil has been performed using transmission infrared spectroscopy. However, this method will have to be modified due to the prohibition of the use of car-bon tetrachloride, used as a solvent in this method. Another method of measuring the absorption of infrared radiation is horizontal attenuated total reflection( HATR), where benzene could be used as a solvent. A description of the HATR method, its advantages and disadvantages are presented.

Requirements that sensors used in diagnostic systems must meet are defined. The sensors currently available are characterised. The possibilities of obtaining special sensors for diagnosing machines with piston-connecting rod mechanisms are presented.