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Tytuł:
Effect of Particle Sizes of Slag on Reduction Characteristics of Nickel Slag-Coal Composite Briquette
Autorzy:
Li, Xiaoming
Li, Yi
Xing, Xiangdong
Wang, Yanjun
Wen, Zhenyu
Yang, Haibo
Powiązania:
https://bibliotekanauki.pl/articles/2049420.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
resources reutilization
nickel slag
particle size
direct reduction
reduction characteristics
Opis:
Nickel slag has a high-content iron and is a secondary utilization resource with great development potential. The coal-based direct reduction is an innovative technology that can be used to utilize the iron resources in nickel slag. The effect of the particle size of nickel slag on the strength and the reduction of nickel slag-coal composite briquettes were investigated. Four samples with particle size of 75~106 μm, 106~150 μm, 150~270 μm, and >270 μm were selected. The drop strength increased 9.4 times and the compressive strength reached 281.1 N when the nickel slag particle size decreased from >270 μm to 75~106 μm. The reduction degree determined by the data from the thermogravimetric experiment indicated that its maximum was 79.545%. The reduction experiments performed at 1200°C for 45 minutes indicated that the nickel slag with particle sizes between 75~106 μm were appropriate for the reduction of the nickel slag-coal composite briquettes.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 1; 127-134
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of moving loads in elastic multibody systems with parametric model reduction techniques
Zastosowanie techniki parametrycznej redukcji modelu do symulacji ruchomych obciążeń w sprężystym układzie wieloczłonowym
Autorzy:
Fischer, M.
Eberhard, P.
Powiązania:
https://bibliotekanauki.pl/articles/950682.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
multibody systems
model reduction
parametric reduction
odkształcenia sprężyste
model redukcji
metoda parametryczna
Opis:
In elastic multibody systems, one considers large nonlinear rigid body motion and small elastic deformations. In a rising number of applications, e.g. automotive engineering, turning and milling processes, the position of acting forces on the elastic body varies. The necessary model order reduction to enable efficient simulations requires the determination of ansatz functions, which depend on the moving force position. For a large number of possible interaction points, the size of the reduced system would increase drastically in the classical Component Mode Synthesis framework. If many nodes are potentially loaded, or the contact area is not known a-priori and only a small number of nodes is loaded simultaneously, the system is described in this contribution with the parameter-dependent force position. This enables the application of parametric model order reduction methods. Here, two techniques based on matrix interpolation are described which transform individually reduced systems and allow the interpolation of the reduced system matrices to determine reduced systems for any force position. The online-offline decomposition and description of the force distribution onto the reduced elastic body are presented in this contribution. The proposed framework enables the simulation of elastic multibody systems with moving loads efficiently because it solely depends on the size of the reduced system. Results in frequency and time domain for the simulation of a thin-walled cylinder with a moving load illustrate the applicability of the proposed method.
W sprężystym układzie wieloczłonowym rozważane są duże, nieliniowe ruchy ciał sztywnych oraz małe odkształcenia sprężyste. W rosnącej liczbie zastosowań, np. W przemyśle motoryzacyjnym, procesach toczenia i frezowania, pozycja sił działających na ciało sprężyste jest zmienna. Redukcja rzędu modelu, niezbędna by umożliwić efektywną symulację, wymaga wyznaczenia funkcji ansatz, które zależą od zmiennej pozycji sił. Przy wielkiej liczbie możliwych punktów interakcji rozmiar zredukowanego systemu rósłby gwałtownie, gdyby stosować klasyczny schemat syntezy modów składowych (Component Mode Synthesis). Jeśli wiele węzłów jest potencjalnie obciążonych, lub obszar styku nie jest znany a priori, w ujęciu przedstawionym w artykule system opisuje się przy pomocy zależnej od parametru pozycji sił. Umożliwia to zastosowanie metod parametrycznej redukcji rzędu modelu. W artykule opisano dwie techniki oparte na interpolacji macierzowej, które transformują poszczególne systemy zredukowane, umożliwiają interpolację macierzy zredukowanych systemów i pozwalają wyznaczyć systemy zredukowane dla dowolnej pozycji sił. Zaprezentowano dekompozycję w trybie online-offline oraz opis rozkładu sił na zredukowanym ciele sprężystym. Zaproponowany schemat postępowania umożliwia efektywną symulację sprężystych układów wieloczłonowych z ruchomymi obciążeniami, gdyż zależy ona wyłącznie od rozmiaru zredukowanego systemu. Przedstawiono wyniki symulacji w dziedzinie czasu i częstotliwości dla cienkościennego cylindra z ruchomym obciążeniem, które ilustrują możliwości zastosowań proponowanej metody.
Źródło:
Archive of Mechanical Engineering; 2014, LXI, 2; 209-226
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model of Interactive System for Training in the Proper Use of Hearing Protection Devices
Autorzy:
Górski, P.
Powiązania:
https://bibliotekanauki.pl/articles/176568.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active noise reduction
hearing protectors
Opis:
In 2011, over 520 thousand persons worked in hazardous conditions (according to the GUS). Among hazardous factors related to working environment noise was found to be the most common one, threatening 199,6 thousand people (52.9% threats-per-persons related to working environment). The prevalence of workplace noise and increasing awareness of effects of its impact on the human body causes increase of the demand for knowledge of the methods of noise reduction. Due to the lack of knowledge concerning the proper use of hearing protectors, effective noise exposure in the real world may be about a dozen dB higher than the declared assumed protection value. For this reason, in Central Institute for Labour Protection – NRI “The interactive system for learning the correct use of hearing protectors” has been developed. The system includes a multimedia guide on hearing protectors supplemented by video tutorials, training materials with training hearing protectors, and software for evaluation of the activities of the trainee.
Źródło:
Archives of Acoustics; 2014, 39, 1; 11-15
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Active Noise Reduction Algorithm Based on NOTCH Filter and Genetic Algorithm
Autorzy:
Górski, P.
Morzyński, L.
Powiązania:
https://bibliotekanauki.pl/articles/177549.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active noise reduction
hearing protectors
Opis:
Application of active noise reduction (ANR) systems in hearing protectors requires the use of control algorithms to ensure stability of the ANR system and at the same time highly effective active noise reduction. A control algorithm based on NOTCH filters is an example of solutions that meet these criteria. Their disadvantage is operation over a narrow frequency band and a need for prior determination of frequencies to be reduced. This paper presents a solution of the ANR system for hearing protectors which is controlled with the use of modified NOTCH filters with parameters determined by a genetic algorithm. Application of a genetic algorithm allows to change the NOTCH filter reference signal frequency, and thus, adapt the filter to the reduced signal frequency.
Źródło:
Archives of Acoustics; 2013, 38, 2; 185-190
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-objective optimization problem in the OptD-multi method
Autorzy:
Błaszczak-Bąk, Wioleta
Sobieraj-Żłobińska, Anna
Kowalik, Michał
Powiązania:
https://bibliotekanauki.pl/articles/221473.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
reduction
OptD method
optimization
LiDAR
Opis:
New measurement technologies, e.g. Light Detection And Ranging (LiDAR), generate very large datasets. In many cases, it is reasonable to reduce the number of measuring points, but in such a way that the datasets after reduction satisfy specific optimization criteria. For this purpose the Optimum Dataset (OptD) method proposed in [1] and [2] can be applied. The OptD method with the use of several optimization criteria is called OptD-multi and it gives several acceptable solutions. The paper presents methods of selecting one best solution based on the assumptions of two selected numerical optimization methods: the weighted sum method and the ε-constraint method. The research was carried out on two measurement datasets from Airborne Laser Scanning (ALS) and Mobile Laser Scanning (MLS). The analysis have shown that it is possible to use numerical optimization methods (often used in construction) to obtain the LiDAR data. Both methods gave different results, they are determined by initially adopted assumptions and – in relation to early made findings, these results can be used instead of the original dataset for various studies.
Źródło:
Metrology and Measurement Systems; 2019, 26, 2; 253-266
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reduction of Industrial Nickel Oxides with a Hydrogen Bearing Gas Between 523 and 673K
Autorzy:
Plascencia, G.
Powiązania:
https://bibliotekanauki.pl/articles/352276.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nickel oxides reduction
hydrogen reduction
Avrami-Erofeyev kinetic model
nucleation and growth
activation energy
Opis:
Reduction of three industrial nickel oxides (Goro, Tokyo and Sinter 75) with a hydrogen bearing gas was revisited in the temperature interval from 523 to 673 K (250 to 400°C). A pronounced incubation period is observed in the temperature interval tested. This period decreases as the reduction temperature increases. Thermogravimetric data of these oxides were fitted using the Avrami-Erofeyev kinetic model. The reduction of these oxides is controlled by a nucleation and growth mechanism of metallic nickel over the oxides structure. Rate kinetic constants were re-evaluated and the activation energy for the reduction of these oxides was re-calculated.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 781-789
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Different Plants Extracts on Silver Nanopar ticles Green Synthesis
Autorzy:
Velgosova, O.
Mražíková, A.
Veselovský, L.
Willner, J.
Fornalczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/351682.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nanoparticles
silver
biosynthesis
reduction agents
TEM
Opis:
Three plants extracts were used for biosynthesis of Ag nanoparticles (AgNPs). AgNPs nucleation process requires effective reduction agents which secure Ag+ to Ag0 reduction and also stabilizing/capping agents. The UV-vis and TEM observation revealed that the best results were obtained by R. officinalis leaf extract. The strong SPR band peak appeared at the wavelength 418 nm. Synthetized AgNPs were globular, fine (~20 nm), uniform and stabile throughout the experiment. A rapid rate of AgNPs synthesis was also significant and economically advantageous factor. Fine (10-20 nm) and globular nanoparticles were synthetized also by U. dioica leaf extract, but the stability of nanoparticles was not permanent. Despite V. vitis-idaea fruit extract contains a lot of reducing agents, UV-vis did not confirm the presence of AgNPs in solution. Synthetized Ag particles were very unstable, Ag particles agglomerated very fast and clearly indicated sediment was formed.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 2; 665-670
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of Nickel Nanoparticles Using Nickel Raffinate Separated by Solvent Extraction from The Spent FeCl3 Etching Solution
Autorzy:
Park, Il-Jeong
Swain, Basudev
Kim, Dae-Weon
Kim, Geon-Hong
Han, Deok-Hyun
Jung, Hang-Chul
Powiązania:
https://bibliotekanauki.pl/articles/354453.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nickel
recycling
solvent extraction
chemical reduction
Opis:
FeCl3 bearing etching solution is mainly used for etching of metals used in shadow masks, PCBs and so on. Due course of Invar alloy etching process the FeCl3 bearing etching solution get contaminated with Ni2+ which affect adversely the etching efficiency. Hence, FeCl3 bearing etching solution discarded after several cycle of operation causes an environmental and economic problem. To address both the issues the etching solution was purified through solvent extraction and remained Ni2+ recovered by wet chemical reduction using hydrazine. For optimum Fe3+ extraction efficiency, various extraction parameter were optimized and size and morphology of the recovered pure Ni powder was analyzed. The reported process is a simple process to purify and recover Ni from industry etching solution.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 2; 531-534
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model reduction problem of linear discrete systems: Admissibles initial states
Autorzy:
Abdelhak, A.
Rachik, M.
Powiązania:
https://bibliotekanauki.pl/articles/229165.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
linear discrete systems
model order reduction
Opis:
Given a linear discrete system with initial state x0 and output function yi , we investigate a low dimensional linear system that produces, with a tolerance index ϵ, the same output function when the initial state belongs to a specified set, called ϵ-admissible set, that we characterize by a finite number of inequalities. We also give an algorithm which allows us to determine an ϵ-admissible set.
Źródło:
Archives of Control Sciences; 2019, 29, 1; 41-55
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determinants of the experts evaluation of journals in economic sciences
Autorzy:
Osiewalski, Jacek
Osiewalska, Anna
Powiązania:
https://bibliotekanauki.pl/articles/703006.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
scientometrics
multiple regression statistical model
model reduction
Opis:
In 2015 an important part of the official evaluation of Polish scientific journals was left to experts’ judgement. In this paper we try to establish which observable factors (with available data) are closely related to the outcome of experts’ evaluation of Polish journals in economic sciences. Using the multiple regression statistical model we show that only 5 variables (out of 17) significantly explain almost 50% of the empirical variance of the experts’ evaluation. The determinants of particular interest, not entering the formal criteria and not related to the impact on global science, are: the number of citations mainly in Polish journals and the affiliation with the Polish Academy of Sciences.
Źródło:
Nauka; 2017, 1
1231-8515
Pojawia się w:
Nauka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Modeling of Copper Reduction in Fire Refining Process
Autorzy:
Kolczyk, E.
Miczkowski, Z.
Czernecki, J.
Powiązania:
https://bibliotekanauki.pl/articles/354138.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
numerical modelling
copper reduction
anode furnace
tuyere
Opis:
Copper reduction represents one of the steps in the process of fire refining of blister copper. Process of copper reduction with natural gas as performed in the anode furnace was modeled. Numerical analysis was conducted using the IPSA (Inter- Phase-Slip Algorithm) module of PHOENICS package and standard turbulent model k - ε. The model takes into account the liquid phase - slag and phase of natural gas which is supplied through the tuyere from the bottom of the charge. Calculations were made for two different diameters of tuyeres for supply of reducer. Based on the calculations and analysis, it was found out that the gas flow which causes strong movement in the bath guarantees homogeneous composition of the liquid copper in each process stage. Application of a tuyere with a larger diameter results in a greater intensity of the reduction process and better use of the reducer.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2A; 521-528
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recovery of Pig Iron from Copper Smelting Slag by Reduction Smelting
Autorzy:
Erdenebold, U.
Choi, M.-H.
Wang, J.-P.
Powiązania:
https://bibliotekanauki.pl/articles/355067.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
copper slag
reduction
pig iron
fayalite
recovery
Opis:
Copper slag is a by-product obtained during smelting and refining of copper. Copper smelting slag typically contains about 1 wt.% copper and 40 wt.% iron depending upon the initial ore quality and the furnace type. Main components of copper slag are iron oxide and silica. These exist in copper slag mainly in the form of fayalite (2FeO ·SiO2 ). This study was intended to recover pig iron from the copper smelting slag by reduction smelting method. At the reaction temperature of below 1400°С the whole copper smelting slag was not smelted, and some agglomerated, showing a mass in a sponge form. The recovery behavior of pig iron from copper smelting slag increases with increasing smelting temperature and duration. The recovery rate of pig iron varied greatly depending on the reaction temperature.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 4; 1793-1798
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Evaluation of the Vibration Reduction Index for Structural Joints
Autorzy:
Ramis, J.
Segovia, E.
Alba, J.
Carbajo, J.
Godinho, L.
Powiązania:
https://bibliotekanauki.pl/articles/177736.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
finite element model
vibration reduction
structural joints
Opis:
The present paper addresses the analysis of structural vibration transmission in the presence of struc- tural joints. The problem is tackled from a numerical point of view, analyzing some scenarios by using finite element models. The numerical results obtained making use of this process are then compared with those evaluated using the EN 12354 standard vibration reduction index concept. It is shown that, even for the simplest cases, the behavior of a structural joint is complex and evidences the frequency dependence. Comparison with results obtained by empirical formulas reveals that those of the standards cannot accurately reproduce the expected behavior, and thus indicate that alternative complementary calculation procedures are required. A simple methodology to estimate the difference between numerical and standard predictions is here proposed allowing the calculation of an adaptation term that makes both approaches converge. This term was found to be solution-dependent, and thus should be evaluated for each structure.
Źródło:
Archives of Acoustics; 2012, 37, 2; 189-197
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamics and Kinetics Analysis on Carbothermic Reduction of Calcined Magnesite in Vacuum
Autorzy:
Tang, Qifeng
Ao, Jinqing
Peng, Biyou
Guo, Biao
Yang, Tao
Powiązania:
https://bibliotekanauki.pl/articles/2125546.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
calcined magnesite
carbothermic reduction
vacuum
thermodynamics
kinetics
Opis:
The carbothermic reduction of calcined magnesite in vacuum was studied. By thermodynamic analysis, the starting temperature of reduction reaction dropped from 2173K to 1523K when system pressure dropped from 1 atmosphere to 100 Pa. The experiments were carried out at different conditions under 10~100 Pa and the experimental results shown that the reduction extent of MgO improved by increasing the reaction temperature and time, the pellet forming pressure as well as adding fluoride as catalyst. The rate-determining step of carbothermic reduction process was gas diffusion with the apparent activation energy of 241.19~278.56 kJ/mol.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 3; 1021--1026
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study on the Recovery of Zinc and Pig Iron from Byproducts after Steelmaking Dust Treatment
Autorzy:
Wang, Jei-Pl
Powiązania:
https://bibliotekanauki.pl/articles/2203737.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
steelmaking dust
reduction
recovery
zinc
pig iron
Opis:
In this study, a research was conducted to recover metallic zinc and pig iron and to improve the purity and the recovery rate through a reduction process for zinc and iron in the byproducts that are generated after steelmaking dust treatment. As the result of the calcination, it was confirmed that Cl (6.06%) and K (3.37%) decreased to Cl (2.75%) and K (0.22%), respectively. For the zinc powder that was recovered with reaction temperature of 1100°C, reaction time of 4 hours, and argon gas of 1L/min as the optimal conditions. The measurement for the purity of zinc was 99.8% and the recovery rate was 92.14%. The melt reduction for recovering pig iron from the residue was reacted under reaction temperature of 1600°C, flux composition (CaO:SiO2) of 1:1, and reducing agent infusion ratio (residue: C) of 14:1, and the pig iron was measured to have a purity of 87.7% and a recovery rate of 91.81%.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 1; 205--208
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
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