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Tytuł:
Computer vision based on Raspberry Pi system
Autorzy:
Abdulhamid, Mohanad
Odondi, Otieno
Al-Rawi, Muaayed
Powiązania:
https://bibliotekanauki.pl/articles/1837769.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
computer vision
raspberry Pi system
system wizyjny
Raspberry Pi
Opis:
The paper focused on designing and developing a Raspberry Pi based system employing a camera which is able to detect and count objects within a target area. Python was the programming language of choice for this work. This is because it is a very powerful language, and it is compatible with the Pi. Besides, it lends itself to rapid application development and there are online communities that program Raspberry Pi computer using Python. The results show that the implemented system was able to detect different kinds of objects in a given image. The number of objects were also generated displayed by the system. Also the results show an average efficiency of 90.206 % was determined. The system is therefore seen to be highly reliable.
Źródło:
Applied Computer Science; 2020, 16, 4; 85-102
1895-3735
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical constituents of water hyacinth (Eichhornia crassipes) methanol leaf extract and its effect on selected enzymes of Periplaneta americana
Autorzy:
Adeleke, G.E.
Adedosu, O.T.
Ehigie, L.
Adegbola, P.I.
Olaniyi, A.A.
Agoola, T.O.
Ehigie, A.F.
Powiązania:
https://bibliotekanauki.pl/articles/2096284.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Eichhornia crassipes
spectroscopy
chromatography
Periplaneta americana
antioxidant enzymes
esterases
Opis:
Eichhornia crassipes (water hyacinth) possesses several biological properties. Periplaneta americana (cockroach) is a household insect pest that can disseminate pathogens. The present study analyses the chemical constituents of water hyacinth leaf methanol extract and its in vitro effects on antioxidant and esterase enzymes in cockroaches. Water hyacinth methanol extract (WHME) was subjected to gas chromatography-flame ionization detection (GC-FID). Crude enzyme preparations were obtained from nymph and adult cockroaches. In vitro effects of different concentrations (10–80 μg/ml) of WHME on superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), acetylcholinesterase (AChE), and carboxylesterase (CE) in crude enzyme preparations were spectrophotometrically measured using cypermethrin (CYP) and chlorpyrifos (CPF) as reference insecticides. The GC-FID chromatogram of WHME showed the presence of gallic acid, para-hydroxybenzoic acid, eritosin, gentisic acid, catechin, protocatechuric acid, quercetin, and eugenol. The WHME and CPF reduced catalase in adults and SOD in nymphs, while CYP and CPF reduced SOD activity in the adults of P. americana. GST was significantly increased by WHME in both nymph and adult cockroaches. AChE was reduced by WHME, CYP, and CPF in nymphs, while CE was increased by WHME in nymphs and adults as compared to the control. In conclusion, our study indicates a high phenolic content in the water hyacinth leaf methanol extract, which increased the activities of the antioxidant enzymes AChE and CE in P. americana. The results also show that the efficacy and the mode by which the extracts could induce toxicity depend on the growth stage of the cockroach.
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2020, 101, 4; 323-336
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of Solar Generation System with 21- CHB-MLI integrated SAPF based ANN and AGPSO tuned PI controller to enhance power quality
Autorzy:
Agrawal, Seema
Kumar, Mahendra
Palwalia, D. K.
Powiązania:
https://bibliotekanauki.pl/articles/41176533.pdf
Data publikacji:
2022
Wydawca:
Politechnika Warszawska, Instytut Techniki Cieplnej
Tematy:
SAPF
shunt active power filter
THD
ANN
artificial neural network
AGPSO algorithm
PCC
bocznikowy filtr mocy czynnej
sztuczna sieć neuronowa
algorytmy
Opis:
This paper represents comparative analysis of artificial neural network (ANN) and AGPSO tuned PI controller based power quality improvement solar generation system. Now a day's Power quality is a major problem due to non-liner load based on power electronics. SAPF is solution to overcome such power quality issues in dynamic manner. With the use of both soft computing controllers based Shunt active power filter, it is tried to reduce harmonics (distortions), compensate reactive power, enhance power quality and power factor correction of supply voltage. System comprises 21-Level cascaded H-bridge inverter supplied from photovoltaic panel, series coupling inductor and self supported DC (capacitor) bus. Voltage harmonics of supplied voltage from PV is reduced by 21-level cascades H-bridge inverter in which switching signal is generated by carrier based in phase level shifted pulse width modulation technique. Incremental conductance (IC) MPPT technique is incorporated to maximize PV panel output. Phase locked loop based unit template generation and Levenberg Marquardt algorithm trained ANN and AGPSO tuned PI controller based DC bus voltage regulation is utilized for current quality improvement in SAPF. Comparative results show the effectiveness of ANN controller than A GPSO tuned PI controller. Suggested model is simulated in Matlab/Simulink 2016(b) for effectiveness.
Źródło:
Journal of Power Technologies; 2022, 102, 4; 121-131
1425-1353
Pojawia się w:
Journal of Power Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An arma type pi-sigma artificial neural network for nonlinear time series forecasting
Autorzy:
Akdeniz, E.
Egrioglu, E.
Bas, E.
Yolcu, U.
Powiązania:
https://bibliotekanauki.pl/articles/91816.pdf
Data publikacji:
2018
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
high order artificial neural networks
pi-sigma neural network, forecasting
recurrent neural network
particle swarm optimization (PSO)
Opis:
Real-life time series have complex and non-linear structures. Artificial Neural Networks have been frequently used in the literature to analyze non-linear time series. High order artificial neural networks, in view of other artificial neural network types, are more adaptable to the data because of their expandable model order. In this paper, a new recurrent architecture for Pi-Sigma artificial neural networks is proposed. A learning algorithm based on particle swarm optimization is also used as a tool for the training of the proposed neural network. The proposed new high order artificial neural network is applied to three real life time series data and also a simulation study is performed for Istanbul Stock Exchange data set.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2018, 8, 2; 121-132
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial Structure of Emission Intensity in Capacitive RF Discharge of He:Ne Mixture at Moderate Pressures
Autorzy:
Al-Hawat, Sh.
Akel, M.
Powiązania:
https://bibliotekanauki.pl/articles/1537696.pdf
Data publikacji:
2010-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.Pi
Opis:
The spatial structure of emission intensity in a capacitive radio frequency discharge at 13.56 Mhz in He:Ne mixture with total pressures of more than hundreds of Pascal was studied using the optical emission spectroscopy technique. The spectral line distributions at the axis of the discharge gap vs. the distance between two plane aluminium electrodes were found for: the line of 585.2 nm (Ne) and 447.15 nm (He) in 5:1 ratio of the mixture at pressure of 800 Pa for different driving powers 10, 20, and 30 W; the line of 585.2 nm in the range of 733-4393 Pa at power of 20 W in 10:1 ratio of the mixture; lines of 632.8 + 633.4 nm (Ne) at ratios of 5:1, 10:1, 15:1, a power of 20 W, under pressure of 1400 Pa; lines of 585.2 nm, 632.8 + 633.4 nm, 640.2 nm, and 703.2 nm (Ne) and 447.15 nm, 706.52 nm (He), at a pressure of 1467 Pa and a power of 20 W in ratio 10:1. Under chosen operational conditions, the measured relative spectral intensities for all studied lines in the middle of the discharge gap show the existence of the α-regime in the RF discharge. The dc-bias voltage vs. the total pressure and the dc-bias voltage-power characteristics were obtained at certain conditions.
Źródło:
Acta Physica Polonica A; 2010, 117, 6; 911-916
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fuzzy controller of model reduction distillation column with minimal rules
Autorzy:
Alawad, Nasir
Alseady, Afaf
Powiązania:
https://bibliotekanauki.pl/articles/118163.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
distillation column
model reduction
pi controller
fuzzy inference system
MATLAB tool
kolumna destylacyjna
redukcja modelu
kontroler pi
system wnioskowania rozmytego
narzędzie MATLAB
Opis:
In this paper the control of a binary distillation column is described. This control is done with fuzzy logic, one with PI- like fuzzy controller and the other with modified PI fuzzy controller, using the minimal rules for fuzzy processing. This work is focused on model reduction of Wood and Berry binary distillation column to get the best performance. It is desired to minimize the rules in order to reduce the computation time to make a faster decision. Comparisons will be made between two versions of fuzzy controllers utilizing reduced rules to verify the outputs. The controlled variables are top composition with high concentration and bottom composition with low. To demonstrate the performance of the fuzzy PI control schemes, results are compared with a classical PI controller and optimal methods, like Differential Evolution (DE), Invasive Weed Optimization (IWO). The proposed structure is able to quickly track the parameter variation and perform better in load disturbances and also for set point changes. Then all the processes of the distillation column with itۥ s fuzzy controllers are simulated in MATLAB software as the results are shown.
Źródło:
Applied Computer Science; 2020, 16, 2; 80-94
1895-3735
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of Proportional-Integral Controllers of Grid-Connected Wind Energy Conversion System Using Grey Wolf Optimizer Based on Artificial Neural Network for Power Quality Improvement
Autorzy:
Alremali, Fathi Abdulmajeed M.
Yaylacı, Ersagun Kürşat
Uluer, İhsan
Powiązania:
https://bibliotekanauki.pl/articles/2201727.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
artificial neural network
grey wolf optimizer
PI controller
grid connection
power quality
wind energy
Opis:
This research presents a combination of artificial neural network (ANN) with the grey wolf optimizer (GWO) to improve the power quality of a grid-connected distributed power generation system (DPGS). To assess the effectiveness of the proposed algorithm, a grid-tied of small-scale wind energy conversion system (WECS) is chosen. The term power quality refers to voltage and frequency regulation, and limited harmonics. Power quality improvement is achieved through the cascaded control system's optimal tuning of three proportional-integral (PI) controllers of the grid-side inverter (GSI). However, because the DPGS model is computationally costly, the Artificial Neural Network (ANN) model is utilized as an alternative model for DPGS. Furthermore, the ANN model is employed in conjunction with the GWO to boost the optimization precision and minimize the execution time of GWO. The considered power system was repetitively simulated to obtain the input-output datasets, which validate and train the ANN model. According to the ANN model's performance evaluation, the correlation coefficient (R) is close to one, while the mean squared error (MSE) is near zero. These findings demonstrate the ANN model's great accuracy in approximating the DPGS model. Using MATLAB/Simulink, the system's performance is evaluated using the optimum values obtained using GWO-ANN for various wind speed profiles. It showed the suggested power quality method’s improved stability, convergence behavior, the effectiveness of the control mechanism, and the robustness of the proposed topology.
Źródło:
Advances in Science and Technology. Research Journal; 2022, 16, 3; 295--305
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Czasowe uwarunkowania współpracy szeregowo-równoległego kontrolera CPLD z mikrokomputerem Raspberry PI i podsystemem PPI
Time conditions of cooperation of a serialparallel CPLD controller, a Raspberry PI microcomputer and a PPI subsystem
Autorzy:
Arnold, K.
Michalak, S.
Powiązania:
https://bibliotekanauki.pl/articles/155165.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
warunki czasowe
Raspberry Pi
CPLD
układy PPI
time conditions
PPI devices
Opis:
Streszczenie W pracy omówiono właściwości komputerów Raspberry PI. Opisano system z Raspberry PI i rozszerzeniem portów równoległych, korzystający z łącza SPI. Przedyskutowano wymagania czasowe dla komunikacji kontrolera CPLD z komputerem Raspberry i podsystemem PPI. Wyznaczono czasy cykli zapisu i odczytu danych, realizowanych przez Raspberry PI podczas komunikacji z układem CPLD. Przedstawiono wyniki badań, pozwalające na oszacowanie szybkości transferu danych w systemie i wskazanie ograniczeń.
In this paper the hardware and software relations in data transfer between Raspberry Pi and peripheral PPI devices, via a CPLD controller are discussed. The necessity of increasing parallel I/O lines in a microprocessor system based on the Raspberry PI, a popular educational microcomputer module, is shown. An example of the system with the Raspberry PI, the SPI/PPI controller and programmable peripheral interface devices 82C55A is presented (Fig. 1). The time requirements for communication between the Raspberry PI central unit (BCM2835), the SPI/PPI controller and PPI devices are discussed and the examples of timing for 82C55A PPI read and write cycles are shown (Figs. 2 and 3). The software (based on C language and libraries) procedure of time T measurement, for sending of two bytes via SPI (SPI of BCM2835 works in standard master mode) and confirming /STR signal is presented (Fig. 4). The value of this time is not constant. It depends on a few components, also on the delays produced by the operating system. The experimental calculations were carried out for the mode value of T determined on 10000 samples (Fig. 5). The value of fSCK (frequency clock for SPI) and for tSPI (SPI time for one byte) as a function of a different SPI divider were analyzed (Figs. 6 and 7). Finally, the coefficient 2·tSPI/T as a function of the SPI divider was determined and presented (Fig. 8). The obtained results showed the communication speed limitation and enabled us to choose the right SPI clock divider as well as to estimate the time of data transfer via the SPI interface implemented in the CPLD controller.
Źródło:
Pomiary Automatyka Kontrola; 2014, R. 60, nr 7, 7; 465-467
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Implementacja kontrolera SPI/PPI w układzie CPLD dla zastosowań z mikrokomputerem Raspberry PI
Implementation of the SPI/PPI controller in a CPLD structure for the systems with a Raspberry PI microcomputer
Autorzy:
Arnold, K.
Michalak, S.
Powiązania:
https://bibliotekanauki.pl/articles/972186.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
Raspberry Pi
podsystem transmisji równoległej
kontroler magistrali
układy CPLD
PPI subsystem
bus controller
CPLD
Opis:
W pracy wskazano potrzebę rozszerzania portów równoległych w systemach z komputerem Raspberry PI. Przedstawiono możliwości programowalnych układów peryferyjnych (PPI). Zaproponowano rozwiązanie problemu komunikacji komputera Raspberry z układami peryferyjnymi, polegające na wprowadzeniu kontrolera układów PPI, wyposażonego w interfejs SPI. Przedstawiono koncepcję integracji modułu SPI, dekodera adresów układów PPI i enkodera przerwań w strukturze CPLD. Zaprezentowano wyniki implementacji logiki kontrolera w układzie CPLD.
In this paper the necessity of increasing parallel I/O lines in a microprocessor system based on the Raspberry PI, a very popular small educational microcomputer, is described. The possibility of increasing parallel inputs and outputs with a programmable peripheral interface (PPI), and also hardware architecture of 82C55A is presented (Fig. 1). The cooperation rules between the central unit and PPI devices are given. The general block diagrams of the system with the Raspberry PI and the implemented PPI controller, with parallel and serial (SPI) interface, are shown and discussed (Fig. 2). An effective solution of communication between Raspberry PI and 82C55A PPI devices, using an external programmable controller with a simplified SPI, is suggested. The SPI/PPI controller takes over the duties of controlling the modes of 82C55A PPI devices, relieves the central unit and decreases the usage of I/O lines. The instruction sequences are composed of two bytes, the higher one includes codes for creating control signals for the controller and read/write cycles for 82C55A devices, the lower includes the data. The address and data words are written with the confirmation signal /STR (Fig. 3). The controller is responsible for PPI addressing and also takes over the tasks of decoding and receiving interrupts. This version of a controller was implemented in the XC9572XL (Xilinx) device, so we had additionally I/Os fully 5V (CMOS, TTL) tolerant, even though the core power supply of the Raspberry PI and its I/O lines were 3.3 volts. The Behavioral and Post-Fit Simulations results are shown (Figs. 4,5 and 6).
Źródło:
Pomiary Automatyka Kontrola; 2014, R. 60, nr 7, 7; 462-464
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kontroler CPLD dla magistrali zewnętrznej mikrokomputera Raspberry PI
A CPLD controller for the external bus of a Raspbery PI microcomputer
Autorzy:
Arnold, K.
Michalak, S.
Powiązania:
https://bibliotekanauki.pl/articles/152312.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
Raspberry Pi
podsystem transmisji równoległej
kontroler magistrali
układy CPLD
PPI subsystem
bus controller
CPLD
Opis:
W pracy przedstawiono możliwości zwiększania liczby wejść i wyjść równoległych popularnego modułu Raspberry PI z wykorzystaniem programowalnych układów peryferyjnych (PPI). Wskazano na ograniczenia w zakresie rozszerzania portów równoległych, związane z liczbą dostępnych linii I/O Raspberry PI. Zaproponowano rozwiązanie wykorzystujące zewnętrzny kontroler implementowany w strukturze CPLD, odpowiedzialny za adresowanie układów PPI, przyjmowanie zgłoszeń przerwań i wystawienie na magistralę wektora przerwań.
In this paper the possibility of increasing parallel inputs and outputs in a microprocessor system based on an educational microcomputer Raspberry PI (Fig. 1) and a programmable peripheral interface (PPI) is presented. An example of multi-channel communication between the central processor unit, PPI devices and parallel interface modes for 82C55A PPI is described (Fig. 2). A system composed of a Raspberry PI unit, a hardware CPLD controller and four parallel transmission devices is proposed (Fig. 3). The external address/interrupt controller is responsible for external PPI addressing – the word address is written with a confirmation signal /LOAD (Fig. 5), and for registering interrupts. The controller takes over the tasks of decoding and interrupts receiving, so consequently minimizes the time required by the Raspberry PI for interruption of the current program, servicing of the peripheral units, and resumption of the interrupted program. The data bus can be implemented inside the CPLD, but also it is possible to use one of any external level translators with three-state output mode (OE signal). This controller was implemented in one of XC9500XL family devices (Tab. 1). For each device from this family the I/Os are fully 5V (CMOS, TTL) tolerant even though the core power supply of the Raspberry PI is 3.3 volts. In mixed (5V/3.3V/2.5V) systems, a controller can work with low power supply CPU. Use of this one programmable device gives us a chance for creating a flexible controller, which can work with different kind of 8-bit central units.
Źródło:
Pomiary Automatyka Kontrola; 2013, R. 59, nr 8, 8; 766-768
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of robust multi-loop PI controller for improved disturbance rejection with constraint on minimum singular value
Autorzy:
Arun, Pathiran
Muniraj, Rathinam
Boselin Prabhu, S.R.
Jarin, T.
Willjuice Iruthayarajan, M.
Powiązania:
https://bibliotekanauki.pl/articles/27324013.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
multi-loop PI controller
multivariable system
decentralized control
disturbance rejection
robust stability
Opis:
Disturbance rejection performance optimization with constraints on robustness for a multivariable process is commonly encountered in industrial control applications. This paper presents the tuning of a multi-loop Proportional Integral (PI) controller method to enhance the performance of load disturbance rejection using evolutionary optimization. The proposed design methodology is formulated to minimize the load disturbance rejection response and the input control energy under the constraints of robust stability. The minimum singular value of multiplicative uncertainty is considered a multi-loop system robust stability indicator. Optimization is performed to achieve the same, or higher level than the most-explored Direct Synthesis (DS) based multi-loop PI controller, which is derived from a conventional criterion. Simulation analysis clearly proved that the proposed multi-loop PI controller tuning method gives better disturbance rejection, and either, the same or a higher level of robust stability when compared to the DS-based multi-loop PI controller.
Źródło:
Archives of Control Sciences; 2023, 33, 4; 839--859
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zaawansowane metody sterowania kaskadowym układem zbiorników
Advanced Control Systems of Cascade Tanks
Autorzy:
Bakun, P.
Długoński, O.
Piotrowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/276395.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
układ kaskadowy zbiorników
układ regulacji PI
wieloobszarowy układ regulacji
odporny układ regulacji z modelem
cascade tanks
PI control system
multiregional control system
robust control systems
Opis:
W artykule analizowany jest układ trzech kaskadowo połączonych zbiorników z elementami wykonawczymi i pomiarowymi. Zadanie sterowania polega na takiej regulacji przepływem wody za pomocą pompy oraz stopniem otwarcia zaworów, aby jak najdokładniej i jak najszybciej osiągnąć zadaną wysokość słupa cieczy w każdym ze zbiorników. Zaprojektowano trzy układy regulacji poziomu wody w każdym ze zbiorników z wykorzystaniem algorytmów: klasycznego PI, wieloobszarowego i odpornego z modelem. Przeprowadzono analizę porównawczą opracowanych algorytmów sterowania dla stałej i zmiennej trajektorii zadanej. Badania wykonano w środowisku MATLAB/Simulink, komunikującym się z obiektem rzeczywistym za pomocą karty pomiarowej zainstalowanej w komputerze PC.
This paper considers cascade tanks with actuators and measuring elements. The control task is to regulate the pump flow and valve’s degree of opening for reach the desired height of the water in each tank as accurately and as quickly as possible. Three control systems of water level in each tank had been projected using: classic PI controller, multiregional controller and robust controller with model of the object. The comparative analysis of developed control system had been performed for constant and variant reference trajectory. Simulation tests were performed in MATLAB/Simulink environment, which communicates with the object using a data acquisition card installed in PC.
Źródło:
Pomiary Automatyka Robotyka; 2015, 19, 3; 25-30
1427-9126
Pojawia się w:
Pomiary Automatyka Robotyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electronic Structure of KMgH$\text{}_{3}$, KMgH$\text{}_{2}$F, KMgF$\text{}_{3}$ with the Perovskite Structure
Autorzy:
Balawender, R.
Gupta, M.
Orgaz, E.
Komorowski, L.
Powiązania:
https://bibliotekanauki.pl/articles/1943944.pdf
Data publikacji:
1995-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.20.Cf
71.25.Pi
Opis:
The electronic structures of fluoroperovskite KMgF$\text{}_{3}$, hydridoperovskite KMgH$\text{}_{3}$ and the dihydrido-fluoro derivated KΜgH$\text{}_{2}$F have been investigated. The energy bands, density of electronic states and partial wave analysis of the density of electronic states have been determined by means of the non-self-consistent augmented plane wave method with the von Barth-Hedin parametrization for the exchange-correlation term. Our results indicate that all three compounds are ionic insulators. Replacing the hydrogen atom by fluorine atom leads to increasing in the energy gap.
Źródło:
Acta Physica Polonica A; 1995, 88, 6; 1133-1141
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Glutathione S-transferase pi as a target for tricyclic antidepressants in human brain.
Autorzy:
Barańczyk-Kuźma, Anna
Kuźma, Magdalena
Gutowicz, Marzena
Kaźmierczak, Beata
Sawicki, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/1043346.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
tricyclic antidepressants
human brain
glutathione S-transferase pi
Opis:
GST pi, the main glutathione S-transferase isoform present in the human brain, was isolated from various regions of the brain and the in vitro effect of tricyclic antidepressants on its activity was studied. The results indicated that amitripyline and doxepin - derivatives of dibenzcycloheptadiene, as well as imipramine and clomipramine - derivatives of dibenzazepine, inhibit the activity of GST pi from frontal and parietal cortex, hippocampus and brain stem. All these tricyclics are noncompetitive inhibitors of the enzyme with respect to reduced glutathione and noncompetitive (amitripyline, doxepin) or uncompetitive (imipramine, clomipramine) with respect to the electrophilic substrate. Their inhibitory effect is reversible and it depends on the chemical structure of the tricyclic antidepressants rather than on the brain localization of the enzyme. We conclude that the interaction between GST pi and the drugs may reduce their availability in the brain and thus affect their therapeutic activity. On the other hand, tricyclic antidepressants may decrease the efficiency of the enzymatic barrier formed by GST and increase the exposure of brain to toxic electrophiles. Reactive electrophiles not inactivated by GST may contribute in adverse effects caused by these drugs.
Źródło:
Acta Biochimica Polonica; 2004, 51, 1; 207-212
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical and simulation modeling of dual active bridge
Autorzy:
Barlik, Roman
Grzejszczak, Piotr
Koszel, Mikołaj
Powiązania:
https://bibliotekanauki.pl/articles/2173709.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dual active bridge
small-signal analysis
averaged model
transfer function
parasitics
PI controller
podwójny mostek aktywny
analiza małosygnałowa
model uśredniony
funkcja przenoszenia
pasożyty
regulator PI
Opis:
The paper is a structured, in-depth analysis of dual active bridge modeling. In the research new, profound dual active bridge converter (DAB) circuit model is presented. Contrary to already described idealized models, all critical elements including numerous parasitic components were described. The novelty is the consideration of a threshold voltage of diodes and transistors in the converter equations. Furthermore, a lossy model of leakage inductance in an AC circuit is also included. Based on the circuit equations, a small-signal dual active bridge converter model is described. That led to developing control of the input and output transfer function of the dual active bridge converter model. The comparison of the idealized model, circuit simulation (PLECS), and an experimental model was conducted methodically and confirmed the high compatibility of the introduced mathematical model with the experimental one. Proposed transfer functions can be used when designing control of systems containing multiple converters accelerating the design process, and accurately reproducing the existing systems, which was also reported in the paper.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 5; art. no. e142653
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł

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