59 research outputs found

    Store Elements LabView-based Energy-flow Models Developmnet and Implementation in HVAC systems

    Get PDF
    It is well known that store elements such as liquid tanks, water reservoirs, or gas containers, are basic elements in heating, ventilation and air conditioning (HVAC) systems development and implementation. In a wide range of applications they serve as efficient energy storage elements by capturing heat energy amount in hot water form. This paper presents a LabView graphical software-based energy-flow model development for store elements in HVAC systems. In the first research steps the mathematical background describing the energy-flow processes in the considered store element (water tank) it is presented and discussed. Then an original software model has been designed and implemented to simulate the ongoing energy-flow processes. The result of the above mentioned research efforts is a powerful and versatile software toolkit (virtual instrument) well suitable to modeling and simulate complex energy-flow processes in HVAC systems embedding various types of store elements. Beside the elaborated mathematical model concrete software simulation examples and measurement data are also provided in the paper. Not at least, the proposed original model offers a feasible solution for future developments and research in HVAC systems software modeling and simulation purposes

    Last Generation Mechatronics: a Two-level Platform-based Reconfigurable Technology Approach

    Get PDF
    As is well known mechatronic systems currently being designed and developed are often difficult multidisciplinary undertakings. Based on the intrinsic coupling of different implementation technologies, efficient design of mechatronic systems is of primordial importance for development of next generation industrial products. This paper is focused to current and future technological trends aimed to improve the design and implementation processes of mechatronic systems in an increasingly harsh industrial environment. Special attention is dedicated to introduction of the two-level platform-based reconfigurable technology approach. This strategy efficiently combines major advantages of both the hardware and software platform-based development trends in modern mecatronic systems. In order to support the unfolded theoretical arguments a last generation and versatile mechatronic system development is presented and discussed in the paper. The mentioned trends can be used as rough orientation for future mechatronic systems research and implementation activities

    LabView-based Modeling and Evaluation of Solar Photovoltaic Cells Energetic Efficiency

    Get PDF
    As it is well known, an accurate knowledge of solar photovoltaic (PV) cell parameters from experimental data is of major importance for estimate their performances and to implement high energetic efficiency PV plants. In the last decade several solar cell models, respectively a high amount of software toolkits have been developed to evaluate their electrical behavior and performances. This paper is focused to introduce a LabView graphical programming language based solution to conveniently modeling, simulate, and evaluate solar PV cells energetic efficiency. By using their well known electrical equivalent circuits a fast and accurate PV simulator has been designed and implemented for research and energetic efficiency studies. The simulation models used has been validated through comparison of the obtained characteristics with the ones given by the manufacturers of PV panels. The computer-aided simulation results carried out are in a good agreement with the manufacturer’s catalogue data and the LabView-based program can serve as a very useful toolkit for engineers or researchers who require an accurate PV simulator and evaluate the performances of any photovoltaic module

    PP2B and ERK1/2 regulate hyaluronan synthesis of HT168 and WM35 human melanoma cell lines

    Get PDF
    Hyaluronan (HA) is the major glycosaminoglycan component of the extracellular matrix in either normal or malignant tissues and it may affect proliferation, motility and differentiation of various cell types. Three isoforms of plasma membrane-bound hyaluronan synthases (HAS 1, 2 and 3) secrete and simultaneously bind pericellular HA. HAS enzymes are subjects of post-translational protein phosphorylation which is believed to regulate their enzymatic activity. In this study, we investigated the HA homeostasis of normal human epidermal melanocytes, HT168 and WM35 human melanoma cell lines and melanoma metastases. HAS2 and HAS3 were detected in all the samples, while the expression of HAS1 was not detectable in any case. Malignant tissue samples and melanoma cell lines contained extra- and intracellular HA abundantly but not normal melanocytes. Applying HA as a chemoattractant facilitated the migration of melanoma cells in Boyden chamber. The amount of HA was reduced upon the inhibition of calcineurin with cyclosporine A (CsA), while the inhibition of ERK1/2 with PD098059 elevated it in both cell lines. The signals of Ser/Thr phosphoproteins at 57 kD were stronger after CsA treatment, while a markedly weaker signal was detected upon inhibition of the MAPK pathway. Our results suggest opposing effects of the two investigated enzymes on the HA homeostasis of melanoma cells. We propose that the dephosphorylation of HAS enzymes targeted by PP2B augments HA production, while their phosphorylation by the activity of MAPK pathway reduces HA synthesis. As the expression of the HA receptor RHAMM was also significantly enhanced by PD098059, the MAPK pathway exerted a complex attenuating effect on HA signalling in the investigated melanoma cells. This observation suggests that the application of MAPK-ERK pathway inhibitors requires a careful therapeutic design in melanoma treatment
    • …
    corecore