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Number of results: 12
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Abstract

The tax benefits described in “cheap”flag regulations is very influential in the registration of marine vessels. Countries or territories that operate open vessel registers are, as a rule, tax havens. This also means that the registration of marine vessels is currently just one source of income for tax havens thanks to preferential tax regulations. Sea transport is dependent to a far greater extent on tax havens than other branches of the economy. This is due to the character of the maritime economy as well as the tradition of registering vessels under "cheap" flags. Competition among countries interested in the development of their own maritime economy is very characteristic, and open vessel registers are one such form of competition. This phenomenon is not only apparent among OECD and third world countries, but also among the “cheap” flag countries. This competition is largely characterized by international tax competition.

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Authors and Affiliations

Tomasz Lipowski
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Abstract

In this article, an analysis of an innovative system for filtering signals in the audible range (16 Hz - 20 kHz) on programmable logic devices using a filters with a finite impulse response, is presented. Mentioned system was neat combination of software and hardware platform, where in the program layer a multiple programming languages including VHDL, JavaScript, Matlab or HTML were used to create completely useful application. To determine the coefficients of polynomial filters the Matlab Filter Design & Analysis Tool was used. Thanks to the developed graphic layer, a user-friendly interface was created, which allows easily transfer the required coefficients from the computer to the executive system. The practical implementation made on the FPGA platform, specifically on the Altera DE2- 115 development kit with the FPGA Cyclone IV, was compared with simulation realization of Matlab FIR filters. The performed research confirm the effectiveness of filtration in real time with up to 128th order of the filter for both audio channels simultaneously in FPGA-based system.
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Authors and Affiliations

Adrian Lipowski
1
Paweł Majewski
1
Sławomir Pluta
1

  1. Opole University Technology, Opole, Poland
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Abstract

The present article describes selected aspects of investment casting technology for manufacturing of open-cell aluminium. The main focus is, among others, on the precursor thickening. Two groups of total 30 samples were produced, basing on open-cell polyurethane foam used as the precursor. Each of the two sample groups was thickened with a different type of suspension consisting of carbonaceous substances and organic binders. The influence of the coating mixture type was compared, leading to conclusions regarding the desired composition and fluidity of the suspensions. Both sample groups of the obtained open-cell aluminium had stochastic cell distributions, the average pore diameter was 5.2 mm and the PPI index was 8. The apparent densities were respectively: 0.485 g/cm3 and 0.312 g/cm3, which reflected the impact of the precursor coating. Additionally, samples from both groups differed in quality.

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Authors and Affiliations

A.M. Stręk
B. Lipowska
K. Wańczyk
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Abstract

Preliminary tests aimed at obtaining a cellular SiC/iron alloy composite with a spatial structure of mutually intersecting skeletons, using a

porous ceramic preform have been conducted. The possibility of obtaining such a composite joint using a SiC material with an oxynitride

bonding and grey cast iron with flake graphite has been confirmed. Porous ceramic preforms were made by pouring the gelling ceramic

suspension over a foamed polymer base which was next fired. The obtained samples of materials were subjected to macroscopic and

microscopic observations as well as investigations into the chemical composition in microareas. It was found that the minimum width of a

channel in the preform, which in the case of pressureless infiltration enables molten cast iron penetration, ranges from 0.10 to 0.17 mm. It

was also found that the ceramic material applied was characterized by good metal wettability. The ceramics/metal contact area always has

a transition zone (when the channel width is big enough), where mixing of the components of both composite elements takes place.

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Authors and Affiliations

M. Cholewa
B. Lipowska
B. Psiuk
Ł. Kozakiewicz
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Abstract

Extremely intense development of civilization requires from foundry casting technologies very high quality and not expensive castings. In

the foundries, there are many treatments that allow increasing of the final properties of produced castings such as refining, modification,

heat treatment, etc. One of the methods of increasing the quality of the casting by removing inclusions from the liquid alloy is filtration.

The use of ceramic-carbon foam filters in filtration process is still analysed phenomenon that allows improving the final properties of

castings. A modern method of research, testing and synthesis of innovative chemical compositions allows improving the properties of such

filters. In the paper the evaluation of application properties of developed ceramic-carbon bonded foam filters is presented. The quality of

the foam filters is evaluated by Computer Tomography and foundry trials in pouring of liquid metal in test molds. Additionally computer

simulations were made to visualize the flow characteristics in the foam filter. The analysed filters are the result of the research work of

Foundry Research Institute and the Institute of Ceramics and Building Materials, Refractory Materials Department in Gliwice.

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Authors and Affiliations

A. Karwiński
P. Wieliczko
M. Małysza
A. Gil
B. Lipowska
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Abstract

Trials of cast steel filtration using two types of newly-developed foam filters in which carbon was the phase binding ceramic particles have

been conducted. In one of the filters the source of carbon was flake graphite and coal-tar pitch, while in the other one graphite was

replaced by a cheaper carbon precursor. The newly-developed filters are fired at 1000o

C, i.e. at a much lower temperature than the

currently applied ZrO2-based filters. During filtration trials the filters were subjected to the attack of a flowing metal stream having

a temperature of 1650°C for 30 seconds.

Characteristic of the filters’ properties before and after the filtration trial were done. It was found, that the surface reaction of the filter

walls with molten metal, which resulted in local changes of the microstructure and phase composition, did not affect on expected filter

lifetime and filtration did not cause secondary contamination of cast steel.

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Authors and Affiliations

B. Lipowska
P. Wieliczko
M. Asłanowicz
J. Witek
T. Wala
A. Karwiński
A. Ościłowski
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Abstract

In 2014 we finished research works involved in the development of a technology for manufacturing innovative ceramic-carbon foam filters for molten metal alloys filtration, which were financed by the National Centre for Research and Development (NCBiR) from INNOTECH programme resources. A batch of the filters produced in this technology was tested in practice in domestic cast steel and cast iron foundries. The trials were successful and foundries declared their intention to purchase the newly-developed filters for the current production of casts. This provided an incentive for “Ferro-Term” Sp. z o.o. to start design works on the prototype line for a serial production of these filters. At the same time, in co-operation with a scientific consortium, including the co-authors of the technology, i.e. the Institute of Ceramics and Building Materials, Refractory Materials Division in Gliwice, Institute for the Chemical Processing of Coal in Zabrze and Foundry Research Institute in Cracow, the company made a successful attempt to raise some funds for the necessary adaptation of the developed technology from the semi-technical to industrial scale from Intelligent Development Operational Programme. In the article we have presented information on the effects of works performed within the framework of the project entitled “Modernization and adaptation of the existing technological line for purposes related to technology verification and start-up of the production of innovative ceramic-carbon filters for molten metal alloy filtration”.

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Authors and Affiliations

M. Asłanowicz
A. Ościłowski
B. Lipowska
J. Witek
Z. Robak
R. Muzyka
P. Kowalski
K. Wańczyk

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