Search results for: water supply
-
Influence of temperature and nitrogen pressure on the test without active gases for high-temperature proton exchange membrane fuel cells
PublicationHigh-Temperature Proton-Exchange Membrane Fuel Cells (HT-PEMFCs) are a candidate for electrical energy supply devices in more and more applications. Most notably in the aeronautic industry. Before any use, an HT-PEMFC is preheated and after that supplied with its active gases. Only at this state, the diagnostics can be performed. A method of testing not requiring a complete start-up would be beneficial for many reasons. This article...
-
Knowledge economics and the demand for higher education
PublicationThis article suggests that the decreased demand for higher education in Poland is partially caused due to the changes in consumer preferences. The appearance of a cheap and highly accessible form of knowledge offered by the massive open online courses is presumed here to have an effect on the demand for formal higher education. This article proposes an additional perspective to the research on knowledge consumption, especially...
-
The enantiomeric determination of chloro-precursors of methamphetamine
PublicationImpurity profiling and classification of seized methamphetamine may supply valuable information with respect to the conditions and the chemicals used in the illicit methamphetamine manufacture and may provide information on the original source of the sample. Determination of the stereochemical makeup of forensic samples is important as well for the same reasons. Laboratories in many places are engaged in clandestine manufacture...
-
An Intergrated Model of Motion, Steering, Positioning and Stabilization of an Unmanned Autonomous Maritime Vehicle
PublicationIn the paper the aim of an interdisciplinary research is presented. The research method is introduced. An object the unmanned autonomous maritime vehicle is briefly described. The key research problem concerns a combined model of the vehicle motion including the loads of lift and hydrodynamic nature. The model takes into account the gravity and displacement forces, resistance and thrust forces, lift and other hydrodynamic forces....
-
Chemical treatment of crystalline silicon solar cells as a main stage of pv modules recycling = Obróbka chemiczna krzemowych ogniw słonecznych jako najważniejszy etap w recyklingu modułów fotowoltaicznych
PublicationIn recent years, photovoltaic systems have gained worldwide recognition and popularity as a environmentally friendly way of solving energetic problems. However, a problem of utilizing worn out photovoltaic systems, amount of which will rapidly increase in the future, is yet to be solved. Establishing a technology of recycling and reusing obsolete photovoltaic panels is a necessity.Photovoltaic modules in crystalline silicon solar...
-
A 1-nS 1-V Sub-1-µW Linear CMOS OTA with Rail-to-Rail Input for Hz-Band Sensory Interfaces
PublicationThe paper presents an operational transconductance amplifier (OTA) with low transconductance (0.62–6.28 nS) and low power consumption (28–270 nW) for the low-frequency analog front-ends in biomedical sensor interfaces. The proposed OTA implements an innovative, highly linear voltage-to-current converter based on the channel-length-modulation effect, which can be rail-to-rail driven. At 1-V supply and 1-Vpp asymmetrical input driving,...
-
Directions of Energy Transition of Uzbekistan
PublicationThe aim of the paper is to present the changes in the Uzbekistan energy market over the past few years. Uzbekistan is self-sufficient in terms of energy resources, the exploitation of which will last for many years. In 2019, the government adopted the "Concept Note ensuring electricity supply in Uzbekistan in 2020-2030" strategy, which announced the modernization of gas and coal power plants and the construction of new energy facilities,...
-
The Influence of a Photovoltaic Micro-Installation on the Low-Frequency Parameters of Electricity at PCC and Its Impact on the Thermal Characteristics of Selected Devices
PublicationThis manuscript illustrates the measurement results of parameters describing the quality of energy at the PCC (point of common coupling) of a photovoltaic micro-installation that can significantly affect devices in the same power grid. The analyses reflecting heating of selected devices used in domestic installations, which were performed in an isolated laboratory environment, are also indicated. The conducted study aimed at checking...
-
Design advantages and analysis of a novel five-phase doubly-fed induction generator
PublicationPurpose – The purpose of this paper is to provide an analysis of the performance of a new five-phase doubly fed induction generator (DFIG). Design/methodology/approach – This paper presents the results of a research work related to fivephase DFIG framing, including the development of an analytical model, FEM analysis as well as the results of laboratory tests of the prototype. The proposed behavioral level analytical model is based...
-
A 0.5 V Nanowatt Biquadratic Low-Pass Filter with Tunable Quality Factor for Electronic Cochlea Applications
PublicationA novel implementation of an analogue low-power, second-order, low-pass filter with tunable quality factor (Q) is presented and discussed. The filter feature is a relatively simple, buffer-based, circuit network consisting of eleven transistors operating in a subthreshold region. Q tuning is accomplished by injecting direct current into a network node, which changes the output resistance of the transistors and, as a result, modifies...
-
Impacts of Using Exhaust Gas Recirculation and Various Amount of Dimethyl Ether Premixed Ratios on Combustion and Emissions on a Dual-Fuel Compression Ignition Engine
PublicationIn the presented research, the authors dealt with the specific properties of the combustion process of dimethyl ether (DME) in a combustion car (Volkswagen Golf IV) engine AJM 1.9 TDI PDE made by Volkswagen factory. Dimethyl ether is an alternative fuel produced most often from natural gas, which can be used in compression ignition engines as a single fuel or co-burned with diesel oil. This work describes the impacts of using exhaust...
-
Modeling lubricant flow between thrust-bearing pads
PublicationInlet temperature is one of the main inputs in all models for the analysis of fluid film bearing performance. At the same time, inlettemperature distribution and also oil velocity distribution at the inlet are the result of flow phenomena in the gap between the bearingpads. These phenomena are complex and in many cases further affected by any special arrangements of forced oil supply to the gapbetween pads. The reason for such...
-
Assembling and testing of quasi-static hybrid piezoelectric motor based on electroactive lubrication principle
PublicationThe presented paper concerns a novel concept of hybrid piezoelectric motor based on electroactive lubrication principle. Its structure is combined of quasi-static and resonance piezoelectric actuators, synchronizing their work to generate the rotary movement. The hybrid motor topology is compared to the existing piezoelectric motors, regarding its field of applications in embedded systems with very high security requirements. The...
-
A novel methodology for the enantiomeric resolution of methamphetamine, its precursors and intermediates by GC-MS
PublicationImpurity profiling and classification of abused drugs using chiral analytical techniques is of particular interest and importance because of the additional information obtained from this approach. When these methods are applied to the synthesis of illicitly used substances, they can supply valuable information about the conditions/chemicals used in the synthesis. In this study, simultaneous chiral separation of methylamphetamine,...
-
THE MODELLING OF ACCUMULATION AND DISSIPATION OF ENERGY IN MECHANICAL DRIVE SYSTEM
PublicationThis paper presents a modelling of accumulation and dissipation energy in simple drive system. The simple drive system is presented by laboratory stand designed for calculate fatigue life of material for bending and rotation tests pieces. The laboratory stand was prepared to diagnosis of fatigue life of material by use energetic methods. This idea was submitted as utility model to Polish Patent Office. This laboratory stand gives...
-
Matching Exception Class Hierarchies between .NET, Java Environments
PublicationThe paper presents a methodology of exception classification and matching exception messages between .NET andJava environments. The methodology operates on existing exception class hierarchies and proposes two complementingapproaches: automated and manual matching. The automated matching uses the similarity measure to find associationsbetween exception messages from the two sets of classes for the considered programming languages....
-
Mathemathical model of radial passive magnetic bearing
PublicationIn the article mathematical radial model of passive magnetic bearings to ocean engineering units has been presented. The units application in underwater thrusters should increase propulsion systems durability and gives lower maintenance costs. The rotor of electric motor is hanging in magnetic field taken from radial passive magnetic bearings. However axial direction maintenance must be controlled with electromagnets and their...
-
Five-phase induction motor drive with sine-wave filter
PublicationThe paper presents closed loop ac drive with 5 phase induction motor operating with voltage source inverter and sine wave filter. The motor supply voltages and currents have sinusoidal shape. For well known adjustable electric drives the field oriented control method with flux and speed co ntrol can be applied. In the presence of output filter both control and estimation algorithms should be modified due to sine wave filter installation....
-
Design thinking qualifications framework – standardizing the innovative approach to entrepreneurial education delivery to engineering students
PublicationHighly competitive labor market stimulates increasing expectations towards fresh university alumni. It is not enough to be an expert - well educated and often experienced - in chosen discipline. High variability of the business environment, continuous change, number of risks, together with higher work demand than supply, shape clear employers’ expectations: entrepreneurial employees are wanted. On this ground a need for entrepreneurial...
-
Comparison of Downdraft and Updraft Gasification of Biomass in a Fixed Bed Reactor
PublicationThe aim of this study was to compare and analyze the gasification process of beech wood. The experimental investigation was conducted inside a gasifier, which can be operated in downdraft and updraft gasification system. The most important operating parameter studied in this paper was the influence of the amount of supply air on the temperature distribution, biomass consumption and syngas calorific value. The results show that...
-
The Method of Multi-criteria Analysis to Support the Decision on Load or Micro-generation Connection to a Low- or Medium-voltage Power Grid
PublicationThis paper presents a method that supports the decision in terms on selecting the best option of a load connection to a low- or medium-voltage power distribution grid, and of a micro-generation source connection to a low-voltage grid. The method is based on the search for the option with the lowest aggregate assessment measure, which is the weighted average of partial assessment measures determined for each of eight considered...
-
Hydraulic resistance analyses of selected elements of the prototype Stirling engine
PublicationThe paper presents the results of simulation tests of hydraulic resistance and temperature distribution of the prototype Stirling alpha engine supplied with waste heat. The following elements were analyzed: heater, regenerator and cooler. The engine uses compressed air as a working gas. Analyses were carried out for three working pressure values and different engine speeds. The work was carried out in order to optimize the configuration...
-
Design of Intelligent Low-Voltage Load Switch for Remote Control System in Smart Grid
PublicationCurrent low-voltage load switches do not support remote disconnect/connect and real-time monitoring of a disconnect/connect state. Addressing to these issues, this paper presents a low-voltage load switch for a smart remote control system, which uses a one-chip microcontroller board and a DC step motor drive mechanism and provides the feedback on the switch status also. Arrears disconnect and full-pay connect control is implemented...
-
Analysis of Induced Voltages and Power Losses in High Voltage Power Cables for Selected Methods of Cables Sheaths Bonding
PublicationPower is increasingly supplied to city centres with 110 kV cable lines. This is a convenient way to supply power, and practically the only one possible in areas of dense urban development. A high-voltage cable contains a coaxial metallic sheath, in which in normal operation and in fault conditions (during short-circuits) significant line-to-earth voltages can be induced, which threatens electric shock and/or damage to the cable’s...
-
Application of advanced CFD simulations in seakeeping analysis of ships (case study)
PublicationThe novel design process of many types of ships needs estimation of seakeeping properties. Especially ships like Offshore Supply Vessels, Wind Farm Support Vessels, Research Vessels, ferries, military vessels, rescue vessels require extended analysis of ship behavior on rough sea. The main reason for improving ships operability in different sea conditions is need of rising efficiency of propulsion system, reducing hull added resistance,...
-
Automation of the Road Gate Operations Process at the Container Terminal—A Case Study of DCT Gdańsk SA
PublicationThe future increased terminal capacity will result in more container movement through the road complex and rail siding, which are one of the most critical areas (potential bottlenecks) in the container terminal. Truck turnaround time is one of the major factors that customers take into account while deciding how many container volumes they will handle through the container terminal. To enable to optimize increased traffic with...
-
Modelling of spirometry - the application for diagnostic purposes
PublicationThe process of the tissue oxygen supply is the fundamental process of the human life. The lung functioning consists of three processes: the ventilation, the perfusion and the diffusion. The paper deals with one of these processes which is the ventilation process. The quality of the pulmonary ventilation has a strong influence on the patient's health condition. Numerous limitations are imposed on conditions of the lung quality measurement,...
-
Multiple output CMOS current amplifier
PublicationIn this paper the multiple output current amplifier basic cell is proposed. The triple output current mirror and current follower circuit are described in detail. The cell consists of a split nMOS differential pair and accompanying biasing current sources. It is suitable for low voltage operation and exhibits highly linear DC response. Through cell devices scaling, not only unity, but also any current gains are achievable. As...
-
Recycling of photovoltaic modules - legal status, technology, market prospects
PublicationThe increase in the number of manufactured and installed photovoltaic modules and the growing concern about the insufficient supply of pure silicon imply the need to take action to develop infrastructure for recycling PV modules. The article presents a multifaceted analysis of the current state of development of the photovoltaic module recycling sector from a global and national perspective. The essence of the issue was introduced...
-
Multiple output differential OTA with linearizing bulk-driven active-error feedback loop for continuous-time filter applications
PublicationA CMOS circuit realization of a highly linear multiple-output differential operational transconductance amplifier (OTA) has been proposed. The presented approach exploits a differential pair as an input stage with both the gate and the bulk terminals as signal ports. For the proposed OTA, improved linearity is obtained by means of the active-error feedback loop operating at the bulk terminals of the input stage. SPICE simulations...
-
Use of Neural Networks in Diagnostics of Rolling-Element Bearing of the Induction Motor
PublicationBearing defect is statistically the most frequent cause of an induction motor fault. The research described in the paper utilized the phenomenon of the current change in the induction motor with bearing defect. Methods based on the analysis of the supplying current are particularly useful when it is impossible to install diagnostic devices directly on the motor. The presented method of rolling-element bearing diagnostics used indirect...
-
Analytical method for calculation of heat source temperature drop for the Organic Rankine Cycle application
PublicationIn the paper presented are considerations on the cooperation of the limited capacity heat source with the Organic Rankine Cycle unit. Usually the heat source providing thermal energy to the Organic Rankine Cycle (ORC) may have twofold characteristics. It can be in the form of a single phase fluid, i.e. as hot exhaust gas or hot liquid, or in some cases it may be available as a phase changing fluid, as for example, technological...
-
Swarm-Assisted Investment Planning of a Bioethanol Plant
PublicationBioethanol is a liquid fuel for which a significant increase in the share of energy sources has been observed in the economies of many countries. The most significant factor in popularizing bioethanol is the profitability of investments in construction of facilities producing this energy source, as well as the profitability of its supply chain. With the market filled with a large amount of equipment used in the bioethanol production...
-
The Influence of LED Lighting Sources on the Nature of Power Factor
PublicationThis article presents measurements of electric power absorbed by a newly built facility for office and scientific research activities. These measurements highlighted the need for compensation of capacitive reactive power—not predicted by the designer—due to the vast use of LED lighting in the facility. The article also describes a reactive power compensation system, designed on the basis of the above-mentioned measurements, and...
-
Current harmonic controller in multiple reference frames for series active power filter integrated with 18-pulse diode rectifier
PublicationThe paper presents the control system and selected results of experimental tests of the AC/DC power converter consisting of an 18-pulse diode rectifier based on coupled reactors and a serial active power filter. Proportional integral controllers with decoupling components are implemented in multiple reference frames for selective line current harmonic suppression. The regulator is provided with a backtracking anti-windup mechanism...
-
LC-MS and LC-NMR as Complementary Techniques for the Determination of Pharmaceuticals in Dosage Formulations
PublicationPharmaceuticals contain not only pharmacologically active compounds but also a range of excipients. The danger exists that impurities may also be present in such drugs, which may adversely affect their efficacy and even endanger patient health and life. Monitoring the composition of pharmaceutical products is therefore essential. The trace amounts of such impurities in pharmaceuticals are often identified and determined with liquid...
-
Risk of power cables insulation failure due to the thermal effect of solar radiation
PublicationLow-voltage, as well as high-voltage power cable lines, are usually buried in the ground. The ampacity of the power cables in the ground mainly depends on the thermal resistivity of the soil, which may vary in a wide range. A common practice in power cable systems performance is to supply them from a pole of an overhead line. If so, a section of the line is located in free air and can be directly exposed to solar radiation. In...
-
Subjective and Objective Quality Evaluation Study of BPL -PLC Wired Medium
PublicationThis paper presents results of research on the effectiveness of bi-directional voice transmission in a 6 kV mine cable network using BPL-PLC (Broadband over Power Line - Power Line Communication) technology. It concerns both emergency cable state (supply outage with cable shorted at both ends) and loaded with distorted current waveforms. The narrowband (0.5 MHz–15 MHz) and broadband (two different modes, frequency range of 3 MHz–7.5...
-
The Conceptual Research over Low-Switching Modulation Strategy for Matrix Converters with the Coupled Reactors
PublicationIn this paper, different Pulse Width Modulation (PWM) strategies for operating with a low-switching frequency, a topology that combines Conventional Matrix Converters (CMCs), and Coupled Reactors (CRs) are presented and discussed. The principles of the proposed strategies are first discussed by a conceptual analysis and later validated by simulation. The paper shows how the combination of CMCs and CRs could be of special interest...
-
Integrated Three-Level Dual-Phase Inverter
PublicationIn view of reducing the number of inverter legs that provide dual-phase, three-level output voltages (as may be needed in an uninterruptible power supply), and that also provide a wide range of output frequencies (as needed in an advanced motor drive system with wide speed ranges), a three-level, dual-phase inverter topology is presented in this paper. Its three-level attribute was based on the F-type inverter topological concept,...
-
Clean energy in the European Union: Transition or evolution?
PublicationIn this paper, we analyse two phenomena. First, the relationship between greenhouse gases emission and effectiveness of the European Union energy policies and second the transition from the fossil fuels to renewable energy sources. We run two-step data analysis concerning 25 European Union member states in the period from 1990 to 2018. We use information on greenhouse gases emission, introduction of new energy policies, source...
-
Reducing common mode voltage and bearing currents in quasi - resonant DC - link inverter
PublicationIn the paper, a concept of separation of an inverter-fed induction motor drive from its mains supply by two transistor switches inserted in the dc-link circuit is reexamined based on the proposed parallel quasi-resonant dc-link inverter (PQRDCLI). The objective of the paper is to show an advantage of the proposed topology in limiting high frequency common mode voltage and bearing currents. In the laboratory setup, an induction...
-
Simple Measurement Method for Resistive Sensors Based on ADCs of Microcontrollers
PublicationA new, complete measurement method for resistance measurement of resistive sensors for systems based on microcontrollers equipped with analog-to-digital converters (ADCs) is proposed. The interface circuit consists of only four resistors, including a resistive sensor and a reference resistor, connected directly to the microcontroller pins. It is activated only during measurements, which significantly reduces power consumption....
-
Current status and future success of renewable energy in Pakistan
PublicationMismatch between energy demand and supply from last two decades has been increasing because of the domination of expensive imported oil in energy mix of Pakistan. To import crude oil Government paid US $ 9 billion in 2008–2009 to meet the energy demands...
-
The voltage on bus bars of the main switchboard of the car carrier electrical power system during sea trials
Open Research DataThe dataset is part of the research results on the quality of supply voltage on bus bars of the main switchboard of the ship's electrical power system in different states of ship exploitation. The attached dataset contains the measurement results conducted onboard the car carrier during sea trials.
-
The voltage on bus bars of the main switchboard of the car carrier electrical power system at sea trials during maneuvering
Open Research DataThe dataset is part of the research results on the quality of supply voltage on bus bars of the main switchboard of the ship's electrical power system in different states of ship exploitation. The attached dataset contains the measurement results conducted onboard the car carrier at sea trials during maneuvering.
-
The instantaneous flicker sensation level measured in the industrial power system supplying the rolling mill motors
Open Research DataThe dataset presents the instantaneous flicker sensation level measured on the bus bars of the main switchgear of the industrial power network for the supply of rolling mills. The data were obtained during an experiment whose purpose was to determine a level of short-term and long-term flicker caused by voltage fluctuations. In the virtual application...
-
Design of an Autonomous IoT Node Powered by a Perovskite-Based Wave Energy Converter
PublicationThis paper presents the results of experimental research focused on wave energy harvesting and its conversion to power Internet of Things (IoT) devices. The harvesting and conversion process was performed using a wave energy converter (WEC) consisting of a lead zirconate titanate piezoelectric ceramic perovskite material and a prototype power electronic circuit. The designed WEC was considered as a power supply for an end node...
-
Raman miniaturised system for field applications
PublicationRaman spectroscopy is a powerful and versatile research technique with a broad range of potential applications, which includes laboratory studies, on-line industrial process monitoring and field measurements. Scope of the field applications includes environment monitoring, detection of dangerous or prohibited materials and rapid identification of unknown samples. It stimulates development of dedicated Raman measurement equipment...
-
Koncepcja i modelowanie wysokoobrotowego napędu elektrycznego turbosprężarki. Zastosowanie w ogniwach paliwowych pojazdów samochodowych
PublicationAbstract: Electrical vehicles powered by hydrogen fuel cells become a potential alternative to conventional vehicles. The polymer electrolyte membrane (PEM) are typical fuel cells used in fuel cell vehicle (FCV). The global efficiency of a PEM fuel cell stack is greatly impacted by the use of a motorized compressor for the air supply system. The motor-compressor set-up may consume up to 19 % of the energy supplied by the PEM fuel...