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Search results for: DECOMPOSABLE CIRCUITS
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Influence of the method of the control of the hybrid contactless short-circuit limiter on power quality
PublicationW artykule przedstawiono wpływ sterowania bezstykowego ogranicznika prądów zwarciowych na ograniczanie zapadów napięcia. Scharakteryzowano podstawowe własności ogranicznika oraz układu sterowania jego pracą. Ponieważ prąd zwarciowy jest detekowany przez dedykowany superkrótki bezpiecznik sterowanie musi być dostosowane do czasu przedrukowego i łukowego topika, które zależą od aktualnej wartości prądu i aktualnej konfiguracji obwodu....
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Modeling saturation of main magnetic circuit of cage induction motors in presence of eccentricity
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Effects in stator currents of cage motors due to saturation of main magnetic circuit
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On the light intensity dependence of short-circuit current of bilayer organic photovoltaic cells
PublicationPraca przedstawia model zależności prądu zwarcia w organicznych dwuwarstwowych układach fotowoltaicznych od natężenia światła. Model jest oparty na założeniu jednorodnego pola elektrycznego w obu warstwach organicznych. Uwzględniona jest bimolekularna i monomolekularna rekombinacja nośników ładunku przy heterozłączu. Przedstawione zostało porównanie obliczeń teoretycznych i wyników doświadczalnych dla układów z barwnikiem perylenowym...
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Automatic tuning of a resonant circuit in wireless power supply systems for biomedical sensors
PublicationIn this paper, a tuning method of a resonant circuit suited for wireless powering of miniature endoscopic capsules is presented and discussed. The method allows for an automatic tuning of the resonant frequency and matching impedance of a full wave rectifier loading the resonant circuit. Thereby, the receiver tunes so as to obtain the highest power efficiency under given conditions of transmission. A prototype receiver for wireless...
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Magnetic Field Generated by Short Circuit Current in the 110 kV Power System
PublicationElectric fields within tissues induced by magnetic fields including transients or short-term peaks should not be time averaged and be regarded as instantaneous values as established in the ICNIRP (International Commission on Non - Ionizing Radiation Protection) guidelines. Measurements of power lines magnetic fields with regard to human beings exposure are carried out typically with maximum current load at current balance condition...
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Interface circuit for impedance sensors using two specialized single-chip microsystems
PublicationW artykule przedstawiono obwód interfejsu przeznaczony do pomiaru parametrów impedancyjnych czujników lub celek pomiarowych instalowanych na obiektach technicznych. Umożliwia on pomiar modułu i argumentu impedancji w zakresie 10ohm
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DIGITAL HYDRAULICS CIRCUIT BASED ON PWM FUNCTION FOR CONTROLLING HYDRAULIC ACTUATOR POSITION
PublicationHydraulic systems are used in many different industries, such as multi-source hydrostatic drive systems. In traditional hydraulic systems, a proportional servo valve is used to control the position of hydraulic actuators. The low energy efficiency and high cost of these control valves are two major problems with these systems. Digital hydraulics is one of the most unique ideas on how to solve these problems. Researchers like digital...
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Szczególny przypadek zastosowania obwodu elektrycznego. A particular case of electric circuit application
PublicationPrzedstawiono szczególne zastosowanie elektrycznego obwodu zastępczego dobadania hemodynamiki nerki. Cechą wyróżniającą taki obwód jest zasilanie napięciem pulsującym, którego kształt odpowiada zmianom ciśnienia tętniczego. Rozważono możliwość diagnostyki stanu nerki, czyli możliwość odtworzenia zmianami parametrów elektrycznych zmian patologicznych.
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Influence of ci rcuit parameters on the procces of current transfer in thehybrid circuit breaker.
PublicationW artykule przedstawiono działanie hybrydowego bezstykowego ogranicznika prądów zwarciowych w oparciu o symulację komputerową oraz porównanie eksperymentu z symulacją komputerową przy pomocy programu MATLAB i PSPICE. Przedstawiono również wady i zalety obliczeń numerycznych przeprowadzonych z zastosowaniem komercyjnych programów na analizę działania łącznika hybrydowego.W analizie uwzględniono model hybrydowego ogranicznika...
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Current commutation process in a ultra-fast fuse-IGBT hybrid circuit breaker.
PublicationUkład hybrydowy bezpiecznika topikowego i tranzystora IGBT umożliwia bardzo szybkie włączenie do obwodu zwarciowego impedancji ograniczającej wartość prądu. Po eksplozji krótkiego topika bezpiecznika wywołanej narastającym prądem zwarciowym wywołuje w czasie poniżej 2 ms wzrost napięcia na topiku do wartości ok.20 - 25V, po czym prąd jest komutowany do gałęzi z przyrządem półprzewodnikowym typu GTO lub IGBT. Ostateczne wyłączenie...
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Determination of equivalent circuit parameters of an induction motor using field calculation software
PublicationSimulation of the drive system comprising a power electronic converter and an induction motor requires that the equivalent circuit parameters of the motor are known. These parameters can be either measured or calculated. A method of calculation of self and mutual inductances that are parameters of a polyphase model of the motor is presented in the paper. All self-inductances and mutual inductances have been calculated using the...
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An Efficient Framework For Fast Computer Aided Design of Microwave Circuits Based on the Higher-Order 3D Finite-Element Method
PublicationIn this paper, an efficient computational framework for the full-wave design by optimization of complex microwave passive devices, such as antennas, filters, and multiplexers, is described. The framework consists of a computational engine, a 3D object modeler, and a graphical user interface. The computational engine, which is based on a finite element method with curvilinear higher-order tetrahedral elements, is coupled with built-in...
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Expedited Re-Design of Multi-Band Passive Microwave Circuits Using Orthogonal Scaling Directions and Gradient-Based Tuning
PublicationGeometry scaling of microwave circuits is an essential but challenging task. In particular, the employment of a given passive structure in a different application area often requires re-adjustment of the operating frequencies/bands while maintaining top performance. Achieving this necessitates utilization of numerical optimization methods. Nonetheless, if the intended frequencies are distant from the ones at the starting point,...
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Method of earth fault loop impedance measurement without nuisance tripping of RCDs in 3-phase low-voltage circuits
PublicationVerification of electrical safety in low-voltage power systems includes the measurement of earth fault loop impedance. This measurement is performed to verify the effectiveness of protection against indirect contact. The widespread classic methods and meters use a relatively high value of the measuring current (5–20) A, so that they are a source of nuisance tripping of residual current devices (RCDs). The meters dedicated to circuits...
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Novel Inductive Power Transfer Approach Based on Z-Source Network with Compensation Circuit
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A New, Reconfigurable Circuit Offering Functionality of AND and OR Logic Gates for Use in Algorithms Implemented in Hardware
PublicationThe paper presents a programmable (using a 1-bit signal) digital gate that can operate in one of two OR or AND modes. A circuit of this type can also be implemented using conventional logic gates. However, in the case of the proposed circuit, compared to conventional solutions, the advantage is a much smaller number of transistors necessary for its implementation. Circuit is also much faster than its conventional counterpart. The...
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A measurement method for capacitive sensors based on a versatile direct sensor-to-microcontroller interface circuit
PublicationIn the paper, there is presented a new time-domain measurement method for determining the capacitance values of capacitive sensors, dedicated, among others, to capacitive relative humidity sensors. The method is based on a versatile direct sensor-to-microcontroller interface for microcontrollers with internal analog comparators (ACs) and with precision voltage reference sources, e.g. digital-to-analog converters (DACs). The reference...
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Impedance Measurement and Selection of Electrochemical Equivalent Circuit of a Working PEM Fuel Cell Cathode
PublicationThe dynamic impedance analysis of direct methanolfuel cell (DMFC) cathode supplied with pure oxygen is pre-sented. Presented results were obtained during dynamic chang-es of the current density in working fuel cell. Investigation ofthe occurring processes at cathode was carried with dynamicelectrochemical impedance spectroscopy (DEIS). A discussionwas conducted based on the determined correlation parameterχ2. It was shown that...
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A prediction of the fault-induced instability of circuit under test as a new approach in categorisation of faults.
PublicationW artykule przedstawiono nowy sposób kategoryzacji uszkodzeń w analogowych układach elektronicznych. Zaproponowano kryterium oparte na predykcji niestabilności indukowanej przez uszkodzenie w testowanym układzie. Przyjeto, że granicą pomiędzy uszkodzeniem miękkim i katastroficznym jest najmniejsza odchyłka parametru elementu, która sprowadza układ testowany do granicy stabilności. Wzrost wartości odchyłki poza wyznaczony margines...
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A novel dual-band rectifier circuit with enhanced bandwidth for RF energy harvesting applications
PublicationIn recent years, a rapid development of low-power sensor networks, enabling machine-to-machine communication in applications such as environmental monitoring, has been observed. Contemporary sensors are normally supplied by an external power source, typically in a form of a battery, which limits their lifespan and increases the maintenance costs. This problem can be addressed by harvesting and converting ambient RF energy into...
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Composition of fatty acids in selected sorts of biscuits, offered for children
PublicationThe fatty acid (FA) composition, especially total trans-fatty acids (TFA) content in 12 assortments of biscuits offered for children, produced by four different companies, were determined by gas chromatography. Total fat content of the biscuit samples ranged from 2.2 to 22.8 g/100 g of product. The major FAs were palmitic C16:0, oleic C18:1, and linoleic C18:2 acids. Depending on the biscuit type, the total saturated fatty acids...
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The control of the contactless hybrid short-cicruit current limiter
PublicationPrzedstawiono podstawowe zasady sterowania praca bezstykowego ogranicznika prądów zwarciowych. Dokonano analizy czynników wpływających na poprawną pracę bezstykowego ohranicznik aprądów zwarciowych ze szczególnym uwzględnieniem poprawy jakosci energii elektrycznej poprzez eliminację zapadów napiecia.
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The Impact of Lightning Flashes and Sprites on the Earth’s Global Electric Circuit: An Overview of Recent Modeling Results
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A method of self-testing of an analog circuit terminated by an ADC in electronic embedded systems controlled by microcontrollers
PublicationA new self-testing method of analog parts terminated by an ADC in electronic embedded systems controlled by microcontrollers is presented. It is based on a new fault diagnosis method based on on-line (i.e. during measurement), transformations of voltage samples of the time response of a tested part to a square pulse - onto localization curves placed in the measurement space. The method can be used for fault detection and single...
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Selection of circuit geometry for miniaturized microwave components based on concurrent optimization of performance and layout area
PublicationThe paper presents a framework for automated EM-driven circuit geometry selection of miniaturized microwave components. Selection of a particular layout is based directly on miniaturization rates achieved for a set of candidate circuit geometries. Size reduction of the considered structures is obtained by replacing their main building blocks (i.e., conventional transmission lines) with slow-wave composite cells and meander lines....
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Some methods of diagnosis of analog circuit using mixed signal test bus IEEE 1149.4
PublicationW artykule przedstawiono wybrane metody testowania i diagnostyki analogowych układów elektronicznych zamontowanych na pakiecie pomiędzy układami scalonymi wyposażonymi w magistralę IEEE 1149.4. Prezentowane metody dobrano pod kątem stopnia skomplikowania układów testowanych oraz specyficznych właściwości metrologicznych magistrali, które ograniczają możliwości pomiarowe i aplikacyjność metod. Rozważono trzy typy układów testowanych:...
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Effect of hybrid contactless short-cicruit limiters on power quality
PublicationPrzedstawiono działanie bezstykowego ogranicznika prądów zwarciowych w oparciu o symulację komputerową. Szczególną uwagę zwrócono na problem jakości dostarczanej energii elektrycznej poprzez ograniczanie zapadów napięcia za pomocą bezstykowego ogranicznika prądów zwarciowych. W modelowaniu elementów systemu elektroenergetycznego i zapadów napięcia, będących skutkiem zwarć wykorzystano program MATLAB z biblioteką Power System Blockset....
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Impedancje i składowe prądu zaburzeń w obwodach z łącznikami półprzewodnikowymi = Impedances and disturbance current components in the circuits with semiconductor switches
PublicationW referacie przedstawiono pewien sposób określenia impedancji i składowych prądu zaburzeń dla przypadku obwodu z łącznikiem półprzewodnikowym. Określono widmową impedancje obciążenia i impedancje wewnętrzną źródła oraz rozpływy składowych prądu zaburzeń. Zaprezentowano wyniki obliczeń dla pewnego przypadku obwodu. W wnioskach omówiono wpływ przyjętego układu zastępczego źródła zaburzeń oraz częstotliwości charakterystycznej na...
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A Comprehensive Survey on Antennas On-Chip Based on Metamaterial, Metasurface, and Substrate Integrated Waveguide Principles for Millimeter-Waves and Terahertz Integrated Circuits and Systems
PublicationAntennas on-chip are a particular type of radiating elements valued for their small footprint. They are most commonly integrated in circuit boards to electromagnetically interface free space, which is necessary for wireless communications. Antennas on-chip radiate and receive electromagnetic (EM) energy as any conventional antennas, but what distinguishes them is their miniaturized size. This means they can be integrated inside...
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EGATEC: A new high-resolution engineering model of the global atmospheric electric circuit—Currents in the lower atmosphere
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Assessing the Operation System of Fire Alarm Systems for Detection Line and Circuit Devices with Various Damage Intensities
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A LUMPED-CIRCUIT MODEL OF CIRCULAR PISTON TRANSDUCER FOR MODELING ITS PERFORMANCE IN DUAL FREQUENCY OPERATING MODES
PublicationThe paper presents novel network equivalent circuit of piezoceramic circular disc transducer that takes into account thickness and ra dial mode of vibrations. The starting point of the analysis is 4-port description of circular disc element representing the solution of wave equation set in radial and thickness directions. Th e approximate solution for harmonic case is represented in the form of 4x4 matrix, which is syn thesized...
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Thermal and Electrodynamic Risk of Residual Current Devices in the Case of Back-Up Protection by Overcurrent Circuit Breakers
PublicationResidual current operated circuit breakers without integral overcurrent protection should be back-up protected. As back-up protection devices, overcurrent circuit breakers are used. The maximum let-through energy and let-through current of the overcurrent devices were evaluated under laboratory conditions. The thermal and electrodynamic risk of residual current devices was analyzed.
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A measurement method for lossy capacitive relative humidity sensors based on a direct sensor-to-microcontroller interface circuit
PublicationA new time-domain measurement method for determining the capacitance and resistance values of lossy relative humidity capacitive sensors is presented. The method is based on a direct sensor-to-microcontroller interface for microcontrollers with internal analog comparators and timers. The interface circuit consists only of four reference resistors (two reference resistors if a microcontroller includes a voltage reference source),...
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Optimization-Based High-Frequency Circuit Miniaturization through Implicit and Explicit Constraint Handling: Recent Advances
PublicationMiniaturization trends in high-frequency electronics have led to accommodation challenges in the integration of the corresponding components. Size reduction thereof has become a practical necessity. At the same time, the increasing performance demands imposed on electronic systems remain in conflict with component miniaturization. On the practical side, the challenges related to handling design constraints are aggravated by the...
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Magnetic and capacitive couplings influence on power losses in double circuit high voltage overhead transmission line
PublicationPurpose – The paper aims to discuss problems of power and energy losses in a double-circuit overhead transmission line. It was observed from energymeters’ readings, that in such a line, active power losses can be measured as “negative”. The “negative” active power losses appear when the active power injected to the circuit is lower than the active power received at the circuit end. The purpose of this paper is to explain this phenomenon. Theoretical...
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Magnetic and capacitive couplings influence on power and energy measurement in double circuit high voltage overhead transmission line
PublicationThe paper discusses influence of magnetic and capacitive couplings on power and energy measurement in case of double circuit high voltage overhead transmission line. There are presented and discussed various factors influencing the power flow among the line‟s circuits. Mathematical model based calculations results are compared to the real transmission line measurements.
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Practical aspects of testing superconducting electromagnets by the capacitor discharge method taking into account the non-linearity of circuit parameters
PublicationThe article presents selected issues related to the development and testing of the diagnostics systems dedicated for superconducting electromagnets. The systems were constructed to assess the production quality of superconducting electromagnets of the SIS100 synchrotron, a new accelerator being built as part of the Facility of Antiproton and Ion Research (FAIR). One of the systems is used for automatic checking of electrical connection...
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The influence of dynamic load changes on temporary impedance in hydrogen fuel cells, selection and validation of the electrical equivalent circuit
PublicationTo achieve optimal performance of a fuel cell, a reliable monitoring and diagnostic method is required. The currently utilized methods give limited information or they are impossible to use under dynamic working conditions. To obtain comprehensive information about the fuel cell operation we utilized novel dynamic electrochemical impedance spectroscopy. Impedance measurements in dynamic mode were performed on a hydrogen fuel cell,...
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A subdomain model for armature reaction field and open‐circuit field prediction in consequent pole permanent magnet machines
PublicationIn this paper, the machine quantity, such as electromagnetic torque, self and mutual inductances, and electromotive force, is analytically calculated for non-overlapping winding consequent pole slotted machine for open-circuit field and armature reaction. The sub-domain approach of (2-D) analytical model is developed using Maxwell's equations and divide the problem into slots, slot-openings, airgap and magnets region, the magnet...
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Best State Estimate for the Phase Angles of Busbars in Power Systems via Circuit Modeled with DC Load Flow
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Isolation of the relative decrease in magnetic permeability contribution to reluctance of an open magnetic circuit based on stray field measurements
PublicationThe goal of the study was to evaluate a relative decrease in magnetic permeability in open magnetic circuits based on stray magnetic field measurements. The boundary element method was used to simulate magnetic circuits with variable geometry and variable magnetic permeability. The simulated magnetic circuits were rectangular or bone-shaped flat samples. Reluctance was increased in the middle of the samples resulting in leakage...
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Inrush and short circuit current identification based on real-time spectral analysis with the use of the FPGA FFT processor
PublicationW artykule przedstawiono krótkookresową analize widmową prądu załączeniowego i prądu zwarciowego transformatora w czasie rzeczywistym z zastosowaniem procesora FFT zrealizowanego w FPGA. Otrzymane widmo ułatwia rozróżnienie rodzaju prądu, co może być zastosowanei do lepszego sterowania zabezpieczneiem różnicowo-prądowym. Określono tez teoretyczne przebiegi prądów dla przyjetego modelu transformatora. Przeprowadzono ponadto analizę...
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Design and optimisation of combinational digital circuits using modified evolutionary algorithm.Projektowanie i optymalizacja kombinacyjnych układów cyfrowych przy użyciu zmodyfikowanego algorytmu ewolucyjnego.
PublicationW pracy przedstawiono możliwości projektowania i optymalizacji układów kombinacyjnych przy użyciu zmodyfikowanych algorytmów ewolucyjnych. Modyfikacja algorytmów polega na wprowadzeniu chromosomów wielowarstwowych i operatorów działających na nich. Wyniki projektowania czterech układów kombinacyjnych uzyskanych uzyskane tą metodą porównano z następującymi metodami opisanymi w literaturze jak: Mapy Karnaugh, metoda Quine-McCluskey...
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Low-Field NMR Study of Shortcake Biscuits with Cricket Powder, and Their Nutritional and Physical Characteristics
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New model simulations of the global atmospheric electric circuit driven by thunderstorms and electrified shower clouds: The roles of lightning and sprites
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Operational System Modelling in a Focused Fire Alarm System with an Open and Signal Detection Circuit Supervising Railway Station Premises
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Modeling of Electrodynamic Phenomena in an Ultra-Rapid Inductive–Dynamic Actuator as Applied to Hybrid Short-Circuit Breakers - A Review Study
PublicationThis article is a study of the research development of electrodynamic phenomena occurring in ultra-fast electrodynamic drives. These types of linear drives are among the fastest, not only because of the huge accelerations achieved, but, above all, because of the extremely short reaction time. For this reason, electrodynamic drives are used in hybrid short-circuit breakers. The phenomena occurring in this type of drive are actually...
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Brain circuit imprints of developmental 17α-Ethinylestradiol exposure in guppies (Poecilia reticulata): Persistent effects on anxiety but not on reproductive behaviour
PublicationThe effects of endocrine disruptors may vary with the timing of exposure. The physiological implications of adult exposure are present during and shortly after exposure while embryonic exposure can imprint changes manifested in adulthood. In this study, guppy (Poecilia reticulata) embryos were exposed to 2 and 20 ng/L of 17α-ethinylestradiol during development via the mother and reared in clean water from gestation until 6 months...