Wyszukiwarka
Wyniki wyszukiwania dla: THERMAL CONVERSION
-
Sample Rate Conversion Based on Frequency Response Masking Filter
PublikacjaThe sample rate conversion with high resampling ratios requires low-pass digital filters with very narrow transition band which results in high computational complexity and makes filter design problematic. Therefore in this work we propose to use the FRM method, which breaks the filter with a narrow transition band into a group of filters with reduced design requirements. These decreases the number of non-zero coefficients and...
-
Zmiana szybkości próbkowania z zastosowaniem filtrów I-FIR
PublikacjaW pracy omówiono zagadnienie projektowania filtrów I-FIR (Interpolated FIR) na potrzeby algorytmu zmiany szybkości próbkowania (SRC - Sampling Rate Conversion). Przeprowadzono analizę skutków zastosowania filtrów I-FIR, ze szczególnym uwzględnieniem analizy wydajności numerycznej implementacji algorytmów SRC realizujących konwersję pomiędzy standardem szybkości próbkowania CD i DAT. Na koniec opracowano i przeanalizowano warianty...
-
COMPARISON OF SOFTWARE AND HARDWARE REALIZATION OF AES CRYPTOGRAPHIC ALGORITHM
PublikacjaIn this paper hardware and software realization of direct and inverse AES cryptographic algorithm is presented. Both implementations were made using the Virtex-II FPGA and were practically tested. As the criteria of comparison, the resource utilization, achieved performance and power dissipation were chosen. Hardware realization increases throughput of conversion about 190 times over software implementation and decreases the energy...
-
Experimental determination of H2 mass stopping powers for low-energy electrons
PublikacjaWe present experimental mass stopping powers of electrons in gaseous H2 obtained with an electron time- of-flight spectrometer, for the incident electron energy range of 11 to 25 eV. In our procedure, the average energy loss is derived from conversion of the measured electron time-of-flight spectra into equivalent electron energy-loss spectra. Our present results are compared with the only available experimental measurement and...
-
Feasibility Study of Three-Phase Modular Converter for Dual-Purpose Application in DC and AC Microgrids
PublikacjaThe modern concept of a universal converter is intended as a power converter (PC) suitable for application in both dc or ac grids using the same external connectors. This novel family was recently proposed to allow easier integration of renewable energy sources and energy storage systems (ESSs), interfacing with dc/ac grids and/or loads with a minimum redundancy of power switches and passive elements. This kind of solution and...
-
HIERARCHICAL CYCLES IN MODERN POWER SYSTEMS – EXERGY ANALYSIS UNDER PART LOADS
PublikacjaThe aim of the paper is to investigate thermodynamic efficiency of advanced hierarchic power cyclesunder partial loads by using of exergy analyze. Advanced hierarchical power systems arecomposed of few energy conversion cycles, most common are steam and gas cycles in various configurations, but they may contain fuel cells, ORC, lithium bromide absorption chillers and others. Moreover hierarchical cycles can be powered by several...
-
Feasibility Study of Three-Phase Modular Converter for Dual-Purpose Application in DC and AC Microgrids
PublikacjaThe modern concept of a universal converter is intended as a power converter suitable for application in both dc or ac grids using the same external connectors. This novel family was recently proposed to allow an easier integration of renewable energy sources and energy storage systems, interfacing with dc/ac grids and/or loads with a minimum redundancy of power switches and passive elements. This kind of solution and applications...
-
An Ultra-Low-Energy Analog Comparator for A/D Converters in CMOS Image Sensors
PublikacjaThis paper proposes a new solution of an ultra-low-energy analog comparator, dedicated to slope analog-to-digital converters (ADC), particularly suited for CMOS image sensors (CISs) featuring a large number of ADCs. For massively parallel imaging arrays, this number may be as high as tens-hundreds of thousands ADCs. As each ADC includes an analog comparator, the number of these comparators in CIS is always high. Detailed analysis...
-
Automatic detection of abandoned luggage employing a dual camera system
PublikacjaA system for automatic detection of events using a system of fixed and PTZ (pan-tilt-zoom) cameras is described. Images from the fixed camera are analyzed by means of object detection and tracking. Event detection system uses a set of rules to analyze data on the tracked moving objects and to detect defined events. A PTZ camera is used to obtain a detailed view of a selected object. A procedure for conversion between the pixel...
-
Digital structures for high-speed signal processing
PublikacjaThe work covers several issues of realization of digital structures for pipelined processing of real and complex signals with the use of binary arithmetic and residue arithmetic. Basic rules of performing operations in residue arithmetic are presented along with selected residue number systems for processing of complex signals and computation of convolution. Subsequently, methods of conversion of numbers from weighted systems to...
-
Up-conversion white emission and other luminescence properties of a YAG:Yb2O3·Tm2O3·Ho2O3@SiO2 glass-nanocomposite
PublikacjaWe report on a glass-nanocomposite material consisting of yttrium aluminum garnet (Y3Al5O12, YAG) nanocrystals co-doped with Yb3+, Tm3+ and Ho3+ ions as well as entrapped into a SiO2 xerogel. This 94YAG·5Yb2O3·0.8Tm2O3·0.2Ho2O3@SiO2 (abbr. YAG:YbTmHo@SiO2) nanocomposite material has been prepared by sol–gel procedure. Its structure and morphology has been characterized by means of X-ray diffraction (XRD) and scanning electron microscope...
-
Preparation of methanation catalysts for high temperature SOEC by β-cyclodextrin-assisted impregnation of nano-CeO2 with transition metal oxides
PublikacjaThe aim of this work was to prepare and examine the catalytic activity of nanometric CeO2 decorated with transition metal oxides – Ni, Co, Cu, Fe and Mn – towards a high-temperature methanation process under SOEC CO2/H2O simulated co-electrolysis conditions. Samples were prepared using the wet impregnation method via the conventional process and with the addition of native cyclodextrin. The influence of β-cyclodextrin (βCD) onto...
-
Impedance monitoring of corrosion degradation of plasma electrolytic oxidation coatings (PEO) on magnesium alloy
PublikacjaImpedance technique based on continuous multisinusoidal current perturbation was used to explain degradation process of plasma electrolytic oxidation coatings (PEO) on magnesium alloy. An obtained impedance spectrum was fitted by electrical equivalent circuit to describe properties of conversion layer on magnesium alloy. Additionally, galvanostatic mode maintained during experiment, with DC current equal to zero, allowed to achieve...
-
Characterization of d-xylose reductase, XyrB, from Aspergillus niger
PublikacjaD-xylose reductase is a member of the aldo-keto reductase family, and is involved in D-xylose and L-arabinose conversion through the Pentose Catabolic Pathway (PCP) in fungi. In this study, we biochemically characterized a newly identified second D-xylose reductase (XyrB) from Aspergillus niger. This NADPH-dependent reductase is able to efficiently convert D-xylose and L-arabinose, and it has the highest affinity for these sugars...
-
OSC - domain oriented ontology creation system
PublikacjaOntologies are, as part of semantic web, a basic component to enrich content available in the Internet with a meaning understandable for computers. In this publication an architecture and functionality of a domain oriented web portal for collaborative creation and storage of ontologies is presented. The system is being created by Gdańsk University of Technology Electronics, Telecommunications and Informatics faculty's Department...
-
High Temperature Air Combustion and Gasification (HTAC; HTAG)
PublikacjaCombustion and gasification technology utilizing high-cycle regenerative air/steam preheater has drawn increased attention in many application areas. The process is to be realized at temperature level above ash melting point using highly preheated agent. The use of highly preheated media above 900oC provides additional energy in to conversion processes and results in considerable changes to the design of combustion and gasification...
-
Adapting the pinch point analysis to improve the ORC design process
PublikacjaPinch point analysis can be adapted so as to assist in the early stages of designing the ORC systems. Typically used in determining the working parameters of heat exchangers, it can be employed to improve the heat fitting between the source of heat and the working fluids of the ORC system. To attain the parametric match, an algorithm was built enabling quick estimation of the possible heat reception by the specific working fluid....
-
Design and Evaluation of the Compact and Autonomous Energy Subsystem of a Wave Energy Converter
PublikacjaThis paper presents the results of the design process focused on the development of the energy subsystem (ES) of a wave energy converter (WEC). The ES is an important electrical part that significantly affects the energy reliability and energy efficiency of the entire WEC device. The designed ES was intended for compact WECs powering IoT network devices working in the distributed grid. The developed ES is an electronic circuit...
-
Leveraging food waste for electricity: A low-carbon approach in energy sector for mitigating climate change and achieving net zero emission in Hong Kong (China)
PublikacjaIn recent years, food waste has been a global concern that contributes to climate change. To deal with the rising impacts of climate change, in Hong Kong, food waste is converted into electricity in the framework of low-carbon approach. This work provides an overview of the conversion of food waste into electricity to achieve carbon neutrality. The production of methane and electricity from waste-to-energy (WTE) conversion are...
-
Application of wireless communication to small WECS with induction generator
PublikacjaWind energy conversion systems (WECS) seem to be self-evident elements of the future smart grids. Among many generator types the squirrel cage induction generator (SCIG) characterizes robustness and low cost. A full-scale power converter can perform smooth grid connection over wide speed range of multiple-stage geared SCIG. Increasing number of sensors can improve the WECS control and diagnostics but increasing number of thin wires...
-
APPLICATION OF THE HIGH FREQUENCY LINEARIZATION OF THE EAR IN PATIENTS WITH TINNITUS . Metoda linearyzacji narządu słuchu u osób cierpiących z szumami usznymi
PublikacjaThis paper summarises the problem of tinnitus, hypotheses on its causes and the treatment methods. Moreover, a hypothesis on tinnitus origins is explained, based on the mechanisms of the analog-to-digital conversion and quantization. In addition, this paper describes methods of determining the acoustic intensity and spectra of low- level ultrasonic signals, as well as impedance characteristics of an ultrasound transducer. Furthermore,...
-
Old Problems - New Solutions: Conversion of Capitals as a Tool for Shaping the Competitive Position in the Economic Field
PublikacjaThe acts and operations any social actor effectuates in each of the logically distinguished spheres of reality are conditioned by many factors, among which a reliable analysis of the strengths and weaknesses of an agent should be considered of utmost importance. The concept of capitals presented in this article divides the quantity of resources available to all acting agents into four main categories (which allows for determining...
-
Old Problems - New Solutions: Conversion of Capitals as a Tool for Shaping the Competitive Position in the Economic Field
PublikacjaThe acts and operations any social actor effectuates in each of the logically distinguished spheres of reality are conditioned by many factors, among which a reliable analysis of the strengths and weaknesses of an agent should be considered of utmost importance. The concept of capitals presented in this article divides the quantity of resources available to all acting agents into four main categories (which allows for determining...
-
Transient States during Short-circuit in a Line Powered by UPS and its Impact on Earth Fault Loop Impedance Measurement and Power Quality
PublikacjaThe short-circuit in a line powered by Uninterruptible Power Supply (UPS) during different UPS operation modes is presented in the article. The transient state condition related to the short-circuit in a line fed from double conversion On-line UPS is discussed in detail. The results of the measurements of earth fault loop impedance (FLI) in circuits powered by UPS with the instruments of various manufacturers are presented. The...
-
Time variable gain for long range sonar with chirp sounding signal
PublikacjaThe main purpose of applaying Time Variable Gain (TVG) in active sonars with digital signal processing is to reduce dynamic range of echo signal and adapt it to the dynamic range of the analogue to digital conversion. With high transmission losses level, the dynamic range of the input signal in long range sonars can be very high and even exceed 200dB. When chirp sounding signals with matched filtration are used, sonars can raech...
-
Inspired by Nature: The Use of Plant-derived Substrate/Enzyme Combinations to Generate Antimicrobial Activity in situ
PublikacjaThe last decade has witnessed a renewed interest in antimicrobial agents. Plants have received particular attention and frequently rely on the spontaneous enzymatic conversion of an inactive precursor to an active agent. Such two-component substrate/enzyme defence systems can be reconstituted ex vivo. Here, the alliin/alliinase system from garlic seems to be rather effective against Saccharomyces cerevisiae, whilst the glucosinolate/myrosinase...
-
Self-Testing of Analog Parts Terminated by ADCs Based on Multiple Sampling of Time Responses
PublikacjaA new approach for self-testing of analog parts terminated by analog-to-digital converters in mixed-signal electronic microsystems controlled by microcontrollers is presented. It is based upon a new fault diagnosis method using a transformation of the set of voltage samples of the time response of a tested analog part to a square impulse into localization curves placed in a multidimensional measurement space. The method can be used...
-
Enhanced energy conversion as a result of fluid-solid interaction in micro- and nanoscale
PublikacjaIt is known that nano- and micromechanics require new approaches to right describing of surface-like phenomena which lead to an enhanced energy conversion. In this work, a general form of surface forces that consist of a contribution from both the friction and mobility components has been extended to collect the effects of bulk and surface motion of a fluid. Quite similar impact can be observed for a solid-fluid mixture, where...
-
Obtaining of coumarone-indene resins based on light fraction of coal tar 2. Coumarone-indene resins with epoxy groups
PublikacjaCoumarone-indene resins (CIR) with carboxy groups were synthesized via cooligomerization of unsaturated compounds presented in light fraction of coal tar and its fraction boiling out within 423–463 K with the addition of such industrial monomers as styrene, maleic anhydride, glycidyl methacrylate and methacrylic acid. 2,2`-Azobis(2-methylpropionitrile) in the form of 0.2 M solution in toluene was used as an initiator. The effect...
-
The domination of ionic conductivity in tetragonal phase of the organometal halide perovskite CH3NH3PbI3-xClx
PublikacjaOrganometal trihalide perovskites have recently gained extreme attention due to their high solar energy conversion in photovoltaic cells. Here, we investigate the contribution of iodide ions to a total conductivity of the mixed lead halide perovskite CH3NH3PbI3−xClx with a use of the modified DC Hebb–Wagner polarization method. It has been identified that an ionic conductivity dominates in tetragonal phase which is associated with room...
-
Evaluation of Workflow Runtime Platforms in Service Composition
PublikacjaTypically, workflow applications are constructed from basic functionalities that may be realized by alternative services deployed in heterogeneous runtime platforms. Depending on workflow structure and selection of services, the applications differ in attributes such as price, Quality of Service (QoS) and others. In the paper, we propose a method of evaluation of workflow runtime platforms using Data Envelopment Analysis. We present...
-
Small Scale Gasification of Biomass and Municipal Wastes for Heat and Electricity Production using HTAG Technology
PublikacjaCombustion and gasification technology utilizing high-cycle regenerative air/steam preheater has drawn increased attention in many application areas. The process is to be realized at temperature level above ash melting point using highly preheated agent. The use of highly preheated media above 900degC provides additional energy to conversion processes and results in considerable...
-
Katarzyna Januszewicz dr hab. inż.
OsobyAbsolwentka Politechniki Gdańskiej, Wydziału Chemicznego kierunku Technologie Ochrony Środowiska, specjalność Monitoring i Analityka Zanieczyszczeń. Posiada stopień naukowy doktora w zakresie nauk technicznych. Zajmuje się w swoich badaniach od czasów studium doktoranckiego tematyką pirolizy tj. beztlenowej termicznej degradacji odpadów, w szczególności biomasą oraz zużytymi oponami. Badania dotyczą: procesu pirolizy różnego typu...
-
Enriching the Context: Methods of Improving the Non-contextual Assessment of Sentence Credibility
PublikacjaThis paper presents several methods of automatic context enrichment of sentences that need to be evaluated, tagged or fact-checked by human judges. We have created a corpus of medical Web articles. Sentences from this corpus have been fact-checked by medical experts in two modes: contextually (reading the entire article and evaluating sentence by sentence) and without context (evaluating sentences from all articles in random order)....
-
Computer-assisted pronunciation training—Speech synthesis is almost all you need
PublikacjaThe research community has long studied computer-assisted pronunciation training (CAPT) methods in non-native speech. Researchers focused on studying various model architectures, such as Bayesian networks and deep learning methods, as well as on the analysis of different representations of the speech signal. Despite significant progress in recent years, existing CAPT methods are not able to detect pronunciation errors with high...
-
Comparative study of selected fluids for use in supercritical Organic Ranking Cycles
PublikacjaIn view of increasing interest in improving energy efficiency of energy conversion devices, there is an increasing requirement of combined production of heat and electricity as well as demand for increased implementation of renewable energy resources. The micro cogenerative units utilizing the Organic Rankine Cycle are focusing the attention of many research centres around the world. In the present paper calculations of ORC cycles...
-
A Convenient Way to Methylated 2-Imidazolines. Syntheses of Fluorene and Triazine Cyclic Diamidines
PublikacjaOne N-methyl- and 4-substituted 2-imidazolines are described. Fluorene bisimidazolines were obtained in good yield (64-92%), starting from 2,7-dicyanofluorene and ammonium sulfide. In a two-step procedure the crude bisthioamide was reacted with excess diaminoalkane-ethanol (1:1 mixt.) in an oil bath. This new procedure is superior over std. methods. For the sake of comparison, a new triazine bisimidazoline (I) was prepd. by...
-
Piezo 2011, Electroceramics for End-Users VI
PublikacjaThis work extends a power harvesting with using piezoelectric materials. Experimental presents the development of a piezoelectric MEMS generator which has the ability to scavenge mechanical energy of ambient vibrations from their surroundings and transform it into electrical energy that can be used in energy storage applications. Recent literature shows that piezoelectric transduction has received the most attention for vibration-to-electricity...
-
Synthesis of novel dinuclear ruthenium polypyridine dye for dye-sensitized solar cells application
PublikacjaA new dinuclear ruthenium(II) polypyridine complex has been successfully synthesized. The new compound has been characterized by spectroscopic and electrochemical methods. Its potential application as a sensitizing dye in dye-sensitized solar cells has been checked under AM 1.5 G irradiation conditions (100 mW cm−2) and its performance was compared to that of a commercially available mononuclear analogous dye. The overall light-to-electricity...
-
Effective Short -term Forecasting of Wind Farms Power
PublikacjaForecasting a specific wind farm's generation capacity within a 24 hour perpective requires both a reliable forecast of wind, as well as supporting tools. This tool is a dedicated model of wind farm power. This model should include not only general rules of wind to mechanical energy conversion, but also the farm's specific features. This paper present analytical, statistical, and neuron models of wind farm power. The study is based...
-
Influence of excitons interaction with charge carriers on photovoltaic parameters in organic solar cells
PublikacjaWe report on theoretical analysis of excitons annihilation on charge carriers in organic solar cells. Numerical calculations based on transient one-dimensional drift-diffusion model have been carried out. An impact of three quantities (an annihilation rate constant, an exciton mobility and a recombination reduction factor) on current density and concentrations of charge carriers and excitons is investigated. Finally, we discuss...
-
Effect of band gap on power conversion efficiency of single-junction semiconductor photovoltaic cells under white light phosphor-based LED illumination
PublikacjaOn the basis of the detailed balance principle, curves of efficiency limit of single-junction photovoltaic cells at warm and cool white light phosphor-based LED bulbs with luminous efficacy exceeding 100 lm/W have been simulated. The effect of energy band gap and illuminance on the efficiencies at warm and cool light is discussed. The simulations carried out show that maximum power conversion efficiency at 1000 lx reaches 52.0%...
-
Smart Cities System Design Method Based on Case Based Reasoning
PublikacjaThe objective of this paper is to present the results of research carried out to develop a design method for Smart Cities systems. The method is based on the analysis of design cases of Smart Cities systems in cities, the selection of the city appropriate to the requirements for implementation and application. The Case Based Reasoning method was used to develop the proposed design methodology, along with mechanisms of the conversion...
-
Variable Ratio Sample Rate Conversion Based on Fractional Delay Filter
PublikacjaIn this paper a sample rate conversion algorithm which allows for continuously changing resampling ratio has been presented. The proposed implementation is based on a variable fractional delay filter which is implemented by means of a Farrow structure. Coefficients of this structure are computed on the basis of fractional delay filters which are designed using the offset window method. The proposed approach allows us to freely...
-
Dual functionality of amphiphilic 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids: surfactants with catalytic function
PublikacjaA series of amphiphilic 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids were synthesized. Acidic hydrogen sulfate ionic liquids with the alkyl chains C6–C14 are characterized by good surface properties. Their surface properties (adsorption and micellization parameters, degree of ionization of micelles, Krafft temperatures and thermodynamic parameters) were determined. Synthesized ionic liquids were applied as a co-catalyst...
-
Experimental study of the use of electric car powered with stationary solar and electrochemical batteries in Northern Poland
PublikacjaThe subject of this paper is an experimental analysis of a Nissan LEAF electric car equipped with 24 kWh battery, powered from the standalone photo-voltaic (PV) charging station in Gdańsk, Poland. The calculations of charging process efficiency and range of test drives were conducted in two extreme situations (winter and summer) of sunlight and road conditions. Experiments were performed in the Laboratory of Innovative Power Technologies...
-
EMI attenuation in a DC-DC buck converter using GaN HEMT
PublikacjaA dc-dc buck converter using gallium nitride (GaN) high electron mobility transistors (HEMT) is experimentally investigated at the discontinuous current mode (DCM) and at the triangular current mode (TCM) operation. The paper objective is to specify the power conversion efficiency and attenuation of common mode (CM) and differential mode (DM) noise voltage, measured at the line impedance stabilization network (LISN) for compared...
-
Evolution of the HVDC Link Connecting Offshore Wind Farms to Onshore Power Systems
PublikacjaThis paper presents an overview of the DC link development and evolution dedicated to HVDC structure for connecting offshore wind power plants to onshore power systems. The growing demand for the green energy has forced investors in power industry to look for resources further out at sea. Hence, the development of power electronics and industrial engineering has enabled offshore wind farms to be situated further from the shore...
-
Ti3C2 MXenes-based catalysts for the process of α-pinene isomerization
PublikacjaIn this study, the catalytic performance of Ti3C2 MXene materials in the reaction of α-pinene isomerization was demonstrated. The influence of etching agents (HF, HF/H2SO4, and HF/HCl; weight ratios of mixed acids: 1 : 3, 1 : 4, and 1 : 5) on removing Al atoms from MAX phase, creation of an accordion-like structure typical...
-
In-ADC, Rank-Order Filter for Digital Pixel Sensors
PublikacjaThis paper presents a new implementation of the rank-order filter, which is established on a parallel-operated array of single-slope (SS) analog-to-digital converters (ADCs). The SS ADCs use an “on-the-ramp processing” technique, i.e., filtration is performed along with analog-to-digital conversion, so the final states of the converters represent a filtered image. A proof-of-concept 64 × 64 array of SS ADCs, integrated with MOS...