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  • Author: Mariusz Bogdan x
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Effect of Osmotic Dehydration on Mechanical and Rheological Properties of Pumpkin Dried with Microwave Method in Reduced Pressure Conditions

Abstract

The objective of the research was to indicate the impact of sirup type used for osmotic dehydration and the microwaves power for microwave and vacuum drying on the selected mechanical and rheological properties of dried pumpkin. Pumpkin cultivar Rugosa was osmotically dehydrated in three concentrates: apple, aronia and cherry. Initially prepared material was dried with microwave method in the reduced pressure conditions which was within 6-4 kPa at the microwave power which was 240 and 480 W. Dried material was subjected to compression tests and stresses relaxation tests. Compression work values (Pś), cutting work (Pp) and indicators describing material elasticity (a and b) were computed. An initial treatment in the form of osmotic dehydration carried out before microwave drying in the reduced pressure conditions allows obtaining dried pumpkin with a raised resistance to compression and cutting and the decreased elasticity in comparison to dried material obtained from a pumpkin which was not subjected to the initial treatment. Microwaves power influences the values of compression and cutting of dried pumpkin.

Open access
Improvement the systems of exploitation machine/Doskonalenie strategii utrzymania zdatności maszyn

Abstract

It this work was talked over chosen and the new problems of exploitation of folded machine engines, helped with methods of technical diagnostics and monitoring the state. This concerns more and more often: the questions perfecting the effectiveness of methods of diagnosing, systems of preventive exchanges, new solutions of software on stage co-ordinating the decision (one - and the multi - dimension), as and the dedicated systems of diagnosing in engineering of diagnostics. Introduced problems of this study finds in processes of destruction of machine engines his reason, concurrent every machine engine near at hand after her producing, until to liquidation. The be shaping the costs of exploitation of machine engines and the possibilities of applying of well-known strategies of exploitation differentiate in this area the variety of organizational workings. The developing technical diagnostics gives to rational exploitation of machine engines the basis in newly created or the perfected diagnostic systems of exploitation.

Open access
Assessment of Utilization Possibilities of Heat Conducted by Waste Gases Exhaust Pipe of SB 1.5 Drum Drier for Drying Wood Chips

Abstract

Based on the exploitation research, the authors evaluated the possibilities of using the heat conducted through the side surface of the waste gases exhaust pipe of SB 1.5 drum drier for drying wood chips. According to the estimated calculations within one hour approximately 173 thousand of kJ of heat may be obtained from the external surface of the waste gases exhaust pipe with the height of 7 m and temperature of approximately 78°C which constitutes an equivalent of approximately 4 kilo of heating oil. In case the above mentioned heat source for drying wood chips in SPA 20 silo with a volume of 6800 kilo within 50% to 20% humidity is used, one may expect that the drying time will be approximately 100 hours.

Open access
Concept of Computer-Aided Assessment of the Technical Condition of Operated Gas Turbine Vanes

Abstract

The article presents a multi-stage algorithm for automatic (without any human, user – diagnostician intervention) detection of vanes-blades (technical objects) and their surfaces on a digital image, combined with color analysis, aimed at determining the technical condition of the tested turbine elements. The images recorded with the use of a camera, containing previously dismantled from the turbine operated stator vanes, were used as the exemplary analysis material. The paper presents the algorithm for the detection of the vanes’ airfoil surfaces with the impact of the applied techniques and methods of image processing and analysis on the final result (software localization of the vane’s trailing and leading edge), Then, the obtained image data, including the structural changes of both the vane’s coating and material (metallographic testing) were correlated with the surface colour scheme (colour segmentation based on the YCbrCr colour space model). Thanks to this approach, areas on the surface of the blade were distinguished, characteristic for proper, overheated and transient condition.

Open access
Truss Harbor Cranes Modal Design Elements Research

Abstract

Dockside cranes must meet the relevant strength requirements that provide usefulness and not endanger the safety of their use. The vibration effect on structural safety hazard results from the impact of horizontal forces caused by the transport of goods for loading and transverse forces caused by wind, which can be dangerous for correct functioning. In addition, there are often serious effects of climate-related impacts of the environment, material fatigue, which actuates the degradation state of the object. Dynamic loads may therefor cause random effects that devastate the structures or lead to their catastrophic destruction.

Recognizing the need to improve the testing methods of crane structures in order to assess their condition and assess their safety factors - this paper attempts to develop a methodology for testing the degradation of the selected portion of a construction crane - using experimental modal analysis, realized in simulation tests in the Inventor environment as well as at test stand research.

Open access
Study of the state a Francis turbine

Abstract

This paper presents a methodology to evaluate the technical state of a Francis turbine by shaft rotor dynamic simulation. There are several rotor dynamic criteria that define the technical state of a turbo-machine. To feed the shaft rotor dynamic model this delivers the required information to accomplish the technical assessment. The numerical rotor dynamic model uses as input, the field forces obtained by the fluid-solid interaction analysis undertaken over the blades of the runner.

The rotor dynamic numerical simulations allow to determinate the record-in-time of the displacements of any point along the shaft. This information is relevant for diagnosis tasks, because it is possible to decompose it spectrally and to estimate the severity of the vibrations. Comparing the results of the numerical model against those obtained from machines that operates under normal conditions, it is possible to determinate the technical state of the turbo-machine. This allows studying the stability of the turbine working on several operation ranges.

A Francis turbine is a very complex machine that involves many physical phenomena of different nature. In this way, the hydraulic input forces needed by the rotor dynamic model should not be assumed but calculated directly from the fluid interaction over the turbine structure.

Open access
A Hydrogenic Electrolyzer for Fuels

Abstract

In this work - in view of still decreasing crude oil resources and increasing fuel prices - are presented issues concerning research on development of other, alternative fuel sources including those used in water, land and air transport means. One of them is hydrogen which, while burning, does not produce noxious carbon dioxide but only side effects such as heat and clean water.

It is almost true that along with sudden drop of availability and rising price of crude oil many countries face economical paralysis. Any of alternative sources is not capable of supplying even only a basic amount of such energy, not mentioning the whole amount of energy demanded by our civilization. Hydrogen as an independent fuel for internal combustion engines has yet to go a long way to commercialization. to be Co-burning systems (combustion of mixtures)of today used hydrocarbon fuels combined with hydrogen seem closer to this aim. As proved in many investigations the substitution of a part of hydrocarbon fuel by hydrogen enables to make use of beneficial features of both the fuels.

One of possible solutions of the problem may be application of an innovative hydrogenic fuel electrolyzer which is presented and evaluated in this paper.

Open access
Flying Means of Attack of Ships, Possible to Be Used by a Potential Enemy—Analysis of the Threats for Ships the Polish Navy

Abstract

The article presents the analysis of the threats to Polish Navy ships resulting from the development by the Baltic Sea countries of missile systems or turbojet missiles. The most popular varieties and types of missiles that could be used against Polish Navy vessels were described and classified taking into account mainly the potential of the Baltic Fleet of the Russian Federation (BF FR), as well as an analysis of the latest global trends in the area of counteracting these missiles. The article presents the conclusions drawn from exemplary simulations of the attack of modern anti-ship missiles. The article also contains references to the ways of determining the probability of avoiding a rocket attack and the measure of the effectiveness of self-defence of attacked ships. The work contains conclusions regarding desirable traits from the systems of self-defence of ships on the modern battlefield with particular emphasis on the character of the Polish Navy. The article presents an analysis of the threats to ships of the Polish Navy, resulting from the development in the Baltic Sea countries, missile/turbojet anti-ship systems. Were described and classified most popular varieties and types of missiles applicable to fight Polish Navy ships and described latest global trends counteracted against these missiles. The article presents the conclusions drawn from exemplary simulations of the attack of modern anti-ship missiles. The article also contains references to the ways of determining the probability of avoiding a rocket attack and the measure of the effectiveness of self-defence of attacked ships. The work contains conclusions regarding desirable traits from the systems of self-defence of ships on the modern battlefield, with particular emphasis on the nature of the Polish Navy.

Open access