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Tytuł:
An intelligent compound gear-bearing fault identification approach using Bessel kernel-based time-frequency distribution
Autorzy:
Andrews, Athisayam
Manisekar, Kondal
Powiązania:
https://bibliotekanauki.pl/articles/2203369.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
compound gear-bearing faults
Bessel transform
time-frequency distribution
convolutional neural network
Opis:
The most crucial transmission components utilized in rotating machinery are gears and bearings. In a gearbox, the bearings support the force acting on the gears. Compound Faults in both the gears and bearings may cause heavy vibration and lead to early failure of components. Despite their importance, these compound faults are rarely studied since the vibration signals of the compound fault system are strongly dominated by noise. This work proposes an intelligent approach to fault identification of a compound gear-bearing system using a novel Bessel kernel-based Time-Frequency Distribution (TFD) called the Bessel transform. The Time-frequency images extracted using the Bessel transform are used as an input to the Convolutional Neural Network (CNN), which classifies the faults. The effectiveness of the proposed approach is validated with a case study, and a testing efficiency of 94% is achieved. Further, the proposed method is compared with the other TFDs and found to be effective.
Źródło:
Metrology and Measurement Systems; 2023, 30, 1; 83--97
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Applied TVA-PSO for optimal energy efficient integration of renewable energy sources based maximizing TEC levels
Autorzy:
Lasmari, Adel
Zellagui, Mohamed
Powiązania:
https://bibliotekanauki.pl/articles/41186676.pdf
Data publikacji:
2023
Wydawca:
Politechnika Warszawska, Instytut Techniki Cieplnej
Tematy:
renewable distributed generation
optimal energy efficient integration
electric distribution networks
TEC levels
time-varying acceleration particle swarm optimization
odnawialna generacja
optymalna integracja
dystrybucja energii elektrycznej
optymalizacja
Opis:
After the rapid increase in the population demography and industrial revolution, many researchers focus on maintaining the balance between the consumption and the production; in this regard, decentralized production plays an important role to achieve this balance, because of its technical economic aspect such as power losses reduction and voltage profile improvement. These advantages can better exploited through the optimal assessment of Distributed Generation (DG). This paper is interested in the study of the optimal location and size of one and multiple DG based on photovoltaic solar sources PV-DG in Radial Distribution Network (RDN) using the Time Varying Acceleration Particle Swarm Optimization Algorithm (TVA-PSO). This algorithm implemented to maximize the Multi-Objective Functions (MOF) based on the Environmental Pollution Reduction Level (EPRL), the Voltage Deviation Level (VDL), Active Power Loss Level (APLL), the Net Saving Level (NSL), and finally the Short Circuit Level (SCL). The proposed method is tested on the standard IEEE 33-, 69-and 118-bus RDN. Outcomes proves that the proposed TVA-PSO is more efficient to solve the optimal allocation of multiple DGs with high convergence rate and minimum power loss reduction.
Źródło:
Journal of Power Technologies; 2023, 103, 2; 123-137
1425-1353
Pojawia się w:
Journal of Power Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generative modelling of vibration signals in machine maintenance
Autorzy:
Puchalski, Andrzej Adam
Komorska, Iwona
Powiązania:
https://bibliotekanauki.pl/articles/28086927.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
time-frequency analysis
condition monitoring
anomalies detection
deep generative models
variational autoencoder
data distribution
Opis:
The exponential development of technologies for the acquisition, collection, and processing of data from real-world objects is creating new perspectives in the field of machine maintenance. The Industrial Internet of Things is the source of a huge collection of measurement data. The performance of classification or regression algorithms needs to take into account the random nature of the process being modelled and any incomplete observability, especially in terms of failure states. The article highlights the practical possibilities of using generative artificial intelligence and deep machine learning systems to create synthetic measurement observations in monitoring the vibrations of rotating machinery to improve unbalanced databases. Variational AutoencoderVAE generative models with latent variables in the form of high-level input features of time-frequency spectra were studied. The mapping and generation algorithm was optimised and its effectiveness was tested in the practical solution of the task of diagnosing the three operating states of a demonstration gearbox.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 4; art. no. 173488
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A discussion on the optimality of bulk entry queue with differentiated hiatuses
Autorzy:
Vadivukarasi, Manickam
Kalidass, Kaliappan
Powiązania:
https://bibliotekanauki.pl/articles/2175843.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
differentiated hiatus time
steady state probability
waiting-time distribution
optimization of expenses
Opis:
We consider Markovian differentiated hiatuses queues with bulk entries. With the help of the matrix geometric method, we discuss the stability condition for the existence of the steady-state solution of our model and we obtain the stationary system size by using a probability generating function. The stochastic decomposition form of stationary system size and the waiting time distribution of an arbitrary beneficiary are also analysed. Furthermore, we perform the expense analysis using the particle swarm optimization technique and we obtain the optimality of service rate and hiatus rate. Finally, we study the effects of changes in the parameters on some important performance measures of the system through numerical observations.
Źródło:
Operations Research and Decisions; 2022, 32, 2; 137--150
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A sensitivity analysis of kinetic characterizations in continuous flotation circuits under moderate deviations with respect to perfect mixing
Autorzy:
Vinnett, Luis
Pino-Muñoz, Catalina A.
Yianatos, Juan
Díaz, Francisco
Henríquez, Felipe
Powiązania:
https://bibliotekanauki.pl/articles/2146941.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation kinetics
residence time distribution
perfect mixing
flotation rate distribution
industrial flotation circuit
Opis:
This paper studies the effect of moderate deviations with respect to perfect mixing on the estimated kinetic parameters in industrial flotation banks. Radioactive tracer tests and mass balance surveys were performed to characterize the mixing regimes and Cu kinetic responses. For three models (Single Rate Constant, Rectangular and Gamma), two approaches to incorporate the residence time distributions (RTD) in the kinetic characterizations of rougher banks were compared: (i) RTDs measured from the radioactive tracer tests; and (ii) pure perfect mixing in each flotation machine. The measured RTDs did not present significant bypass in the evaluated banks. In all cases, comparable model fitting was obtained with both RTD approaches, which indicates that the kinetic models add sufficient flexibility to compensate for moderate biases in the mixing regime. The studied kinetic models showed non-significant differences in the estimated maximum recoveries (R∞), mean (kmean) and median (k50) rate constants when comparing the process modelling from measured RTDs and pure perfect mixing. However, the Gamma model was more sensitive to the RTD assumption in terms of the shapes of the flotation rate distributions. From the results, kinetic characterizations focused only on model fitting, or on R∞ and kmean (or k50) estimations have low sensitivity to the assumption of perfect mixing when the RTDs present moderate deviations with respect to this regime. Special attention must be paid when characterizing floating components as the perfect mixing assumption may bias the shapes of the flotation rate distributions.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 5; art. no. 152420
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A state-of-the-art review of distribution-of-practice effects on L2 learning
Autorzy:
Serrano, Raquel
Powiązania:
https://bibliotekanauki.pl/articles/2143623.pdf
Data publikacji:
2022-09-27
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
time distribution
intensive instruction
distributed practice
spacing
Opis:
The purpose of this state-of-the-art review is to provide a general overview of recent research on time distribution and second language (L2) learning with special implications for classroom settings. Several studies have been performed to examine how to best distribute the hours of L2 practice to maximize learning by comparing conditions that promote intensive exposure versus others in which L2 input or instruction is more widely spaced. Findings from these studies are relevant not only for practical purposes but also for theory development. This review provides a summary of recent studies as well as suggestions for pedagogical practice. Additionally, it identifies areas for future research concerning the effect of time distribution on L2 learning.
Źródło:
Studies in Second Language Learning and Teaching; 2022, 12, 3; 355-379
2083-5205
2084-1965
Pojawia się w:
Studies in Second Language Learning and Teaching
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Discussion on the transient behavior of single server Markovian multiple variant vacation queues
Autorzy:
Vadivukarasi, Manickam
Kalidass, Kaliappan
Powiązania:
https://bibliotekanauki.pl/articles/2099427.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Markovian queue
multiple variant vacations
transient solution
waiting-time distribution
Opis:
We consider an M/M/1 queue where beneficiary visits occur singly. Once the beneficiary level in the system becomes zero, the server takes a vacation at once. If the server finds no beneficiaries in the system, then the server can take another vacation after the return from the vacation. This process continues until the server has exhaustively taken all the J vacations. The closed form transient solution of the considered model and some important time-dependent performance measures are obtained. Further, the steady state system size distribution is obtained from the time-dependent solution. A stochastic decomposition structure of waiting time distribution and expression for the additional waiting time due to the presence of server vacations are studied. Numerical assessments are presented.
Źródło:
Operations Research and Decisions; 2021, 31, 1; 123--146
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Introducing key advantages of intensified flotation cells over conventionally used mechanical and column cells
Autorzy:
Hassanzadeh, Ahmad
Safari, Mehdi
Khoshdast, Hamid
Güner, Mustafa K.
Hoang, Duong H.
Sambrook, Tim
Kowalczuk, Przemyslaw B.
Powiązania:
https://bibliotekanauki.pl/articles/2146874.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
pneumatic flotation cells
energy input
mean particle retention time
fine particles
bubble size distribution
Opis:
The present paper introduces the key advantages of ImhoflotTM, JamesonTM, and RefluxTM flotation cells over the conventionally used mechanical and column cells from different perspectives. The impact of slurry mean retention time, bubble size distribution, and energy input was studied for all cell types. The mean retention time of laboratory scale ImhoflotTM (V030-cell) and RefluxTM flotation cells (RFC100) were measured experimentally using KCl as a tracer. Also, initially a statistical and practical overview of previously installed ImhoflotTM, and JamesonTM cells was presented in this work. It was found that more industrial data is available for the JamesonTM cell. The diagnostic results showed that RefluxTM, JamesonTM, and ImhoflotTM functionally operate similarly based on providing intensive turbulence in the downcomer. They were initially applied to the Australian and the UK coal industries and installed in the cleaning stage of flotation circuits, while there are now more applications in a wide variety of minerals across the world in different flotation stages. First pilot trials on a Russian gold ore were reported operating both JamesonTM and ImhoflotTM cells at the rougher-scalper and cleaner stages providing superior results using the ImhoflotTM cell as rougher-scalper and the JamesonTM at the cleaner. Formation of sub-micron and micron-sized bubbles, effective hydrodynamic characteristics, and low capital and operating costs were reported as major advantages of intensified flotation cells over the conventionally used ones in improving the recoverability of ultra-fine particles. Literature data showed that these cells provide greater gas-hold-up values (40-60%) over the mechanical (5-20%) and column cells (5-25%) with substantially lower power inputs. It was indicated that low mean slurry retention time could lead to a potential enhancement in their throughputs, but further industrial measurements are required to prove this statement. The RefluxTM cell showed a plug-flow mixing regime, while ImhoflotTM V-Cell followed the trend of perfect mixing and plug-flow dispersion regimes.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 5; art. no. 155101
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Machine learning algorithms for the problem of optimizing the distribution of parcels in time-dependent networks: the case study
Autorzy:
Tarapata, Zbigniew
Kulas, Wojciech
Antkiewicz, Ryszard
Powiązania:
https://bibliotekanauki.pl/articles/2124716.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
parcel distribution
optimization
machine learning algorithms
time-dependent networks
dystrybucja przesyłek
optymalizacja
algorytmy uczenia maszynowego
sieci zależne czasowo
Opis:
In the paper we present machine learning algorithms for the problem of optimizing the distribution of parcels in stochastic time-dependent networks, which have been built as a part of some Distribution Optimization System. The problem solved was a modified VRPTW (Vehicle Routing Problem with Time Windows) with many warehouses, a heterogeneous fleet, travel times depending on the time of departure (stochastic time-dependent network) and an extensive cost function as an optimization criterion. To solve the problem a modified simulated annealing (SATM) algorithm has been proposed. The paper presents the results of the algorithm learning process: the calibration of input parameters and the study of the impact of parameters on the quality of the solution (calculation time, transport cost function value) depending on the type of input data. The idea is to divide the input data into classes according to a proposed classification rule and to propose several strategies for selecting the optimal set of calibration parameters. These strategies consist in solving some multi-criteria optimization tasks in which four criterion functions are used: the length of the designated routes, the computation time, the number of epochs used in the algorithm, the number of designated routes. The subproblem was building a network model of travel times that is used in constructed SATM algorithm to determine the travel time between recipients, depending on the time of departure from the start location. An attempt has been made to verify the research hypothesis that the time between two points can be estimated with sufficient accuracy depending on their geographical location and the time of departure (without reference to the micro-scale, i.e. the detailed structure of the road network). The research was conducted on two types of data for Warsaw: from transport companies and one of the Internet traffic data providers. Learning the network model of travel times has produced very promising results, which will be described in the paper.
Źródło:
Archives of Transport; 2022, 61, 1; 133--147
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Sound Field Distribution in Architecturally Diverse Temples
Autorzy:
Błaszczak, Paweł
Berdowska, Sylwia
Berdowski, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/1953508.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustical field distribution
reverberation time
definition
mean free path
critical distance
Opis:
The results of the research, which aimed to analyze the acoustic properties of selected sacred buildings located in the city of Częstochowa, Poland are presented in the paper. Three architecturally unusual and completely different from each other churches were selected for the study. The churches differed in shape of their buildings, cubic volume, years of construction, interior furnishings, etc. Nine different objective parameters were used to describe the physical properties of acoustical field in the studied churches. Various factors characterizing the acoustic properties of each building were determined, such as the distribution of sound pressure level (SPL), reverberation time T30, definition D50. Next, they were thoroughly analyzed, so as to ultimately obtain distributions of individual acoustic parameters in the space of the tested building. It allowed to evaluate the quality of the received verbal or musical message depending on the place where the listener was. Further research on speech intelligibility and the musical quality of churches was performed by determining the averaged values of next four objective acoustic parameters: centre time Ts, speech clarity C50, music clarity C80, and speech transmission index (STI). A new approach to analyzing the objective physical parameters describing the sound field was presented in Sec. 4. Mean free path length and critical distance were determined for the investigated acoustic fields in each church and they were associated with a general geometric factor characterizing the complexity of the room shape. The final part of the work presents a comparative analysis of the obtained results of acoustic quality tests of the temples, and thus their usefulness in terms achieving a maximum intelligibility of speech and music. The interesting similarities were found in the spatial distribution of individual acoustic parameters characterizing the distribution of the acoustic field in temples with completely different architecture.
Źródło:
Archives of Acoustics; 2021, 46, 1; 121-133
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Discrete-time Multi-queue System with a Cycle-based Scheduler
Autorzy:
Burakowski, Wojciech
Sosnowski, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/1839463.pdf
Data publikacji:
2021
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
discrete-time queueing system with vacations
system state distribution
packet sojourn time distribution
virtualized system
Opis:
This paper presents an analysis of a discrete-time multi-queue system handling a number of packet streams. The analysis focuses on calculating system state distribution and packet sojourn time distribution. The method relied upon for determining system state distribution is based on creating a number of equations that are solved numerically. Next, based on the distribution calculated in such a manner, we derive relations for packet sojourn time distribution. The models studied may be useful for instance in a system supporting a number of virtual links (each of a constant bitrate) that share a common physical link. Isolation of performance of those virtual links needs to be assured. Finally, we present some exemplary numerical results showing the usefulness of the proposed analysis for supporting the system dimensioning process.
Źródło:
Journal of Telecommunications and Information Technology; 2021, 2; 68-76
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An aggregate criterion for selecting a distribution for times to failure of components of rail vehicles
Zagregowane kryterium wyboru rozkładu czasu douszkodzenia elementów pojaz dów szynowych
Autorzy:
Selech, Jarosław
Andrzejczak, Karol
Powiązania:
https://bibliotekanauki.pl/articles/1365224.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
time to failure
estimation of probability distribution
reliability of rail vehicles
czas do uszkodzenia
estymacja rozkładu prawdopodobieństwa
niezawodność pojazdów szynowych
Opis:
This paper presents an aggregate method of selecting a theoretical cumulative distribution function (CDF) for an empirical CDF. The method was intended to identify the time of reliable operation of a renewable technical object by applying three criteria based on the following statistics: the modified Kolmogorov–Smirnov (MK-S) statistic, the mean absolute deviation of the theoretical CDF from the empirical CDF, and a statistic calculated on the basis of a log-likelihood function. The values of these statistics were used to rank eleven probability distributions. The data for which calculations were made concerned failures of the driver’s cab lock recorded during five years of operation of a fleet of 45 trams. Before calculating the statistics, the empirical CDF of the examined component was determined using the Kaplan–Meier estimator, and then, using the method of Maximum Likelihood Estimation, the parameters of the analysed theoretical distributions were estimated. The theoretical distributions were then ranked according to the values obtained for each of the assumed criteria: the lower the value for a given criterion, the higher the ranking position, indicating a better fit according to that criterion. Then, based on the three rankings and on weights assigned to the individual criteria, an aggregate criterion (referred to as DESV) was implemented to select the best-fitting probability distribution. The method assumes that the lowest DESV value corresponds to the best-fitting theoretical distribution. In the case of the examined component, this was found to be the generalised gamma distribution. It is shown that if the final decision is based on the aggregate criterion, which takes into account the three criteria for goodness of fit, the reliability of the estimation of the time-to-failure distribution increases, and thus mistakes resulting from the use of only one of the criteria can be avoided.
W pracy przedstawiono zagregowaną metodę doboru dystrybuant hipotetycznych do dystrybuanty empirycznej. Metoda miała na celu identyfikację czasu niezawodnej pracy odnawialnego obiektu technicznego poprzez zastosowanie trzech kryteriów, w których użyto następujących statystyk: zmodyfikowanej statystyki Kołmogorowa-Smirnowa (MK-S), statystyki średniego odchylenia bezwzględnego dystrybuanty hipotetycznej od empirycznej oraz statystyki obliczanej na podstawie zlogarytmowanej funkcji wiarygodności. Wartości tych statystyk posłużyły do rangowania jedenastu rozkładów prawdopodobieństwa. Dane dla których dokonano obliczeń dotyczyły uszkodzeń zamka kabiny motorniczego jakie odnotowano w ciągu pięciu lat użytkowania floty 45 tramwajów. Przed obliczeniem statystyk wyznaczono dystrybuantę empiryczną badanego elementu przy pomocy estymatora KaplanaMeiera, a następnie przy użyciu metody największej wiarygodności oszacowano parametry uwzględnionych w badaniach rozkładów hipotetycznych. Po wyznaczaniu parametrów nastąpiło rangowanie rozkładów hipotetycznych według wartości otrzymanych dla każdego z przyjętych kryteriów, im mniejsza wartość dla danego kryterium tym wyższa pozycja w rankingu, świadcząca o lepszej jakości dopasowania według danego kryterium. Po ustaleniu rankingu według kryteriów zgodności, każdemu z kryteriów zgodności dopasowania dystrybuant modelowych do empirycznej nadano wagi. Następnie na podstawie uzyskanych trzech rankingów oraz wag nadanych poszczególnym kryteriom zgodności wyznaczana jest zagregowana miara zgodności (oznaczona DESV), która służy do wyznaczania najlepszego rozkładu prawdopodobieństwa. W prezentowanej metodzie przyjęto, że najmniejsza wartość DESV wyznacza najlepiej dopasowany rozkład hipotetyczny. W przypadku badanego elementu rozkładem tym okazał się uogólniony rozkład gamma. Pokazano, że na podstawie zagregowanego kryterium uwzględniającego trzy statystyki zgodności dopasowania zwiększa się wiarygodność estymacji rozkładu czasu pracy do uszkodzenia, unikając tym samym błędów jakie można popełnić uzależniając się tylko od jednej z nich.
Źródło:
Eksploatacja i Niezawodność; 2020, 22, 1; 102-111
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of air distribution and process duration on the emissions during combustion of alternative fuel
Wpływ rozdziału powietrza i czasu realizacji procesu na emisje w trakcie spalania paliwa alternatywnego
Autorzy:
Kozioł, Michał
Powiązania:
https://bibliotekanauki.pl/articles/127382.pdf
Data publikacji:
2020
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
refuse derived fuel
primary air flow distribution
combustion time
emissions
grate furnace
paliwa z odpadów
rozkład strumienia powietrza pierwotnego
czas spalania
emisje
palenisko rusztowe
Opis:
One of the greatest problems of environmental protection is the problem of municipal waste management. As the experience of the richest European countries shows, a significant part of it must still be managed by thermal methods. However, currently, numerous countries, including Poland, are moving away from waste incineration processes towards the processes of energetic use of fuels based on them. One of the main combustion technologies of solid waste and fuels based on them is their combustion in grate furnaces. In the article the methodology and results of laboratory tests of the combustion process of refuse derived fuel are presented. The research was carried out on a test stand enabling simulation of processes occurring in furnaces with mechanical grates. In the presented research, variable factors were: the distribution of air flow along the grate length and the total duration of the process. In the research the influence of changes in these factors on CO and NOx emissions was determined. The paper presents both the changes in the emissions of the gases mentioned above over time and the total emissions related to the unit of the formed fuel burnt.
Jednym z największych problemów ochrony środowiska jest problem zagospodarowania odpadów komunalnych. Jak wskazują doświadczenia najbogatszych krajów europejskich, metodami termicznymi zagospodarowywana wciąż musi być znacząca ich część. Jednak obecnie w szeregu państw - w tym w Polsce odchodzi się od procesów spalania odpadów na rzecz procesów energetycznego wykorzystania paliw powstałych na ich bazie. Jedną z głównych technologii spalania odpadów stałych oraz paliw powstałych na ich bazie jest ich spalanie w paleniskach rusztowych. W artykule przedstawiono metodykę i wyniki badań laboratoryjnych procesu spalania paliwa alternatywnego. Badania przeprowadzono na stanowisku badawczym umożliwiającym symulowanie procesów zachodzących w paleniskach z rusztami mechanicznymi. W prezentowanych badaniach czynnikami zmiennymi były: rozkład strumienia powietrza wzdłuż długości rusztu oraz całkowity czas trwania procesu. W badaniach określano wpływ zmian tych czynników na emisję CO i NOx. W pracy przedstawiono zarówno zmiany emisji wymienionych gazów w czasie, jak i wielkości emisji całkowitej odniesione do jednostki spalanego paliwa formowanego.
Źródło:
Proceedings of ECOpole; 2020, 14, 1; 11-17
1898-617X
2084-4557
Pojawia się w:
Proceedings of ECOpole
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and modelling investigation of caesium adsorption on soil samples around DAE facility, India
Autorzy:
Maity, Sukanta
Sandeep, Police
Sahu, Sanjay Kumar
Kumar, A. Vinod
Powiązania:
https://bibliotekanauki.pl/articles/1030685.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CEC
Laboratory batch method
caesium
chemical parameters
distribution coefficient (Kd)
equilibration time
isotherm
rate constant
Opis:
The kinetics and thermodynamics behind the sorption process of Cs (Caesium) on the soil are important to understand as these studies give information about the mobility of Cs in the environment. In the present study, sorption kinetics and the parameters influencing sorption (viz. time of contact, competing ions, temperature, solution pH and Cs concentration) were studied on the soil samples collected from Tarapur area. Site-specific distribution coefficient (Kd) of Cs was also estimated in soil samples collected from different locations across Tarapur, India using laboratory batch method. The effect of soil parameters (viz. pH, cation exchange capacity, organic matter and CaCO3) on Kd values of Cs was also investigated. The data of Cs adsorption on the soil is well fitted with the pseudo-second-order kinetic equation with the correlation coefficient (R2) value of 0.99. The rate constant (k2) of Cs adsorption (at 25 ºC) on collected soil samples was found to be 3.33×105 g µg-1 min-1. In the present study, Cs adsorption data were well fitted with Freundlich and Dubinin–Radushkevich (D–R) isotherm models. The change of enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG) were estimated for the Cs adsorption on soil samples. Results showed that the adsorption process was exothermic (ΔH = -3.69 J mol−1) and favoured at a lower temperature. The calculated ΔG value (< 0) indicates that the Cs sorption on the soil is a spontaneous process. The Kd values were found to the range of 58 ± 2 to 275 ± 10 kg-1. The parametric study indicated CEC to have a stronger influence as compared to pH, OM and CaCO3 in the soil samples.
Źródło:
World Scientific News; 2020, 139, 2; 201-220
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalised Odd Frechet Family of Distributions: Properties and Applications
Autorzy:
Marganpoor, Shahdie
Ranjbar, Vahid
Alizadeh, Morad
Abdollahnezhad, Kamel
Powiązania:
https://bibliotekanauki.pl/articles/1058928.pdf
Data publikacji:
2020-09-04
Wydawca:
Główny Urząd Statystyczny
Tematy:
Frechet distribution
Wiebull distribution
structural properties
failure-time
maximum likelihood estimation
Opis:
A new distribution called Generalized Odd Fréchet (GOF) distribution is presented and its properties explored. Some structural properties of the proposed distribution, including the shapes of the hazard rate function, moments, conditional moments, moment generating function, skewness, and kurtosis are presented. Mean deviations, Lorenz and Bonferroni curves, Rényi entropy, and the distribution of order statistics are given. The maximum likelihood estimation technique is used to estimate the model parameters, and finally applications of the model to a real data set are presented to illustrate the usefulness of the proposed distribution.
Źródło:
Statistics in Transition new series; 2020, 21, 3; 109-128
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
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