Numerical analysis and experimental verification of the electrical impedance tomography method for monitoring of the packed-bed drying process

This paper presents a method for online determination the spatial distribution of the moisture content in material being dried. It might be essential for monitoring and optimal control of the drying processes. The proposed method utilizes electrical impedance tomography. As the exemplary material for experimental research the black chokeberry (Aronia melanocarpa) was used. The relationship between electrical impedance of chokeberry and its moisture content was determined for wide range of frequency (0.02200 kHz). Experimental studies of the spatial distribution of the moisture content was performed in the cylindrical vessel equipped with 8-electrode circumferentially arranged. Voltage signal from the electrodes was acquired simultaneously using high-speed data acquisition module. Due to high impedance of the chokeberries, exceeding 109 Ω for dried matter, extraordinary instrumentation for stimulus sourcing and current measurement was necessary to be applied. On the other hand, raw chokeberries are characterized by several orders of magnitude lower impedance (103104 Ω), especially for high frequency. Wide range of observed impedance was able to be measured owing to use of the voltage stimulation instead of the current stimulation. The image reconstruction problem was solved using iterative Gauss-Newton algorithm in the electrical impedance and diuse optical tomography software package. The obtained results has shown satisfactory ability to localize insuciently dried part of the material. It was proved, that strong dependence between moisture content in chokeberries and its impedance in whole frequency range provides more meaningful information than simple resistance or capacitance measurement. Prospect for the improvement of the spatial resolution of humidity imaging was also discussed

Transfer function matrix model of the bubbling fluidized bed boiler

The paper presents proposal of a model of the fluidized bed boiler adapted for use in model-based controllers e.g. predictive, adaptive or internal model control (IMC). The model has been derived in the form of transfer function matrix which allows its direct implementation in the controller structure. Formulated model takes into consideration the principal cross-coupling between process variables which enables the opportunity to search for feasibility of decoupling control. The results of the identification of the dynamics of the 2 MW industrial bubbling fluidized bed boiler using the proposed model form was presented. According to the experimental data it was found that despite of introduced simplifications presented model allows the boiler behavior prediction

On line diagnostics and self-tuning method for the fluidized bed temperature controller

The paper presents the method of on-line diagnostics of the bed temperature controller for the fluidized bed boiler. Proposed solution is based on the methods of statistical process control. Detected decrease of the bed temperature control quality is used to activate the controller self-tuning procedure. The algorithm that provides optimal tuning of the bed temperature controller is also proposed. The results of experimental verification of the presented method is attached. Experimental studies were carried out using the 2 MW bubbling fluidized bed boiler

PROFESSIONAL ACTIVITY OF WORKING-AGE INHABITANTS OF THE WIELKOPOLSKIE VOIVODESHIP

The main purpose of the paper was to defi ne the determinants of professional activity of working age population. The professional activity of the investigated population, taking into account selected demographic features, namely gender, age, place of residence, were discussed in the article. The inquiry research was carried out in 2013 on the area of the Wielkopolskie voivodeship on 386 people at production age. In addition to the primary data, the secondary data originating from the Social Security Offi ce and Eurostat were used. The conducted research proves that the vast majority of the inquired was professionally active. Among the professionally active, the employed under a contract of employment in full-time employment dominated. Only few of the inquired undertook an additional job. Among women, the main reason for increase of professional activity was obtaining low income from the basic source of income. The investigated women obtained lower incomes than the men

The selected elements of fruit and vegetable companies competitiveness

Celem badań była prezentacja wyników badań ankietowych dotyczących strategii konkurencyjności, prowadzonych wśród 32 przedsiębiorstw sektora owocowo-warzywnego w latach 2010-2013 r. Grupa badawcza została dobrana w sposób celowy i były to jednostki w ramach działu EKD15.3. Z badań wynika, że przedsiębiorstwa wysoko oceniają własne źródła przewagi konkurencyjnej, zwłaszcza w zakresie funkcji i jakości produktów, najsłabiej zaś oceniany jest udział w rynku i ekologizacja oferty produktowej. Mimo pozytywnej opinii na temat przewagi rynkowej nad konkurentami, badani rzadko wskazują na wprowadzanie innowacji, nowych technologii lub reagowanie na potrzeby konsumentów jako źródła tej przewagi. W opinii większości badanych w ich przedsiębiorstwach istnieją dobre warunki dla przewagi jakościowej oraz osiągnięcia specjalizacji technologicznej i produktowej. Z badań wynika, że przedsiębiorstwa wykazują duży potencjał rozwojowy i mają silną pozycję na rynkuThe aim of the paper is to present results of inquiry research concerning competitive strategies, conducted in 32 companies of fruit and vegetable sector in years 2010-2013. The research group was chosen in purposeful selection and they were units functioning in 15.3 NACE section. The conducted research proves that companies quite high evaluate their own sources of competitive advantage, particularly in the area of functions and quality of products In turn, share in market and ecologization of the product offer got the lowest notes. Despite positive opinion on market advantage over competitors, the investigated rarely indicate introduction of innovation, new technologies or reaction consumer needs as sources of the advantage. In the opinion of the majority of the investigated in their companies, there exist good conditions for quality advantage and achievement of technological and product specialization. The research proves that the enterprises have development potential and strong market position

Competitiveness determinants of micro, small and medium-sized enterprises operating in bakery and confectionary industry

W artykule podjęto próbę określenia determinant konkurencyjności przedsiębiorstw sektora MSP w branży piekarniczo-cukierniczej. W tym celu przeprowadzono badania wśród 70 małych i średnich firm zlokalizowanych w województwie wielkopolskim. Z badań wynika, że jedynie co piąte przedsiębiorstwo analizuje swoją pozycję rynkową. Zdaniem ankietowanych, w otoczeniu biznesowym największy wpływ na konkurencyjność ma polityka fiskalna państwa. W przypadku potencjału produkcyjnego badani wskazują na jakość urządzeń i nowoczesne technologie, zaś w sferach sprzedaży i dystrybucji ważne są wizerunek przedsiębiorstwa i relacje z klientami. W grupie czynników o charakterze produktowym kluczową rolę odgrywa jakość. Zatem wobec rosnących wymagań konsumentów konieczna jest dbałość o jakość produktu i wizerunek firmy, a także utrzymywanie dobrych relacji z klientami.A trial to define the most important determinants of competitiveness of SMEs operating in bakery and confectionary industry was undertaken in the paper. Therefore, the survey on 70 SMEs located in the wielkopolskie voivodship was conducted. The research proves that only every fifth enterprise analysed their market position. According to the inquired, fiscal policy of the state is the most important in the business environment. In case of production potential, the investigated indicated quality of equipment and modern technologies, whereas in selling and distribution sphere, company’s image and relations with clients were the most important. In product field, the key role was played by the quality. Regarding to growing consumer requirements, it is necessary to care of product quality and company’s image as well as maintaining good relations with customers

A Fiscal Outlook for Poland Using Generational Accounts

During the next few decades the populations of most developed countries will grow older and older as a result of the low fertility rates since the 1970s and/or the continuously increasing life expectancy. Poland, one of the biggest countries in Central Europe, will be confronted rather seriously by this development. Generational Accounting which was introduced in the early nineties, can illustrate the effects of this ageing process on a country's fiscal situation. We show that the demographic development produces a major problem for the long term stability of Polish public finances. In particular the healthcare system deserves special attention for policy makers in the medium and long run, whilst the general pension system shall stabilise in the long term