Wyniki wyszukiwania - BazTech

1

Peganum Harmala L. plant as green non-toxic adsorbent for iron removal from water

Alsaiari Raiedhah, Shedaiwa Iman, Al-Quadri Fatima, Musa Esraa E., Alqahtani Huda, Alkorbi Faeza, Alsaiari Norah A., Mohamed Mervate M.

Archives of Environmental Protection

|

2024

|

Vol. 50, no 1

3--12

EN

The present work focuses on examining the batch removal of Fe (III) from water using powdered Peganum Harmala seeds, characterized as FT-IR. In this work, several parameters are measured, including contact time, pH, Fe (III) concentration, reaction temperature effect, and adsorbent dose effect. Fe (III) adsorption was assessed using a UV-vis spectrophotometer at a wavelength of 620 nm. The findings demonstrated a positive correlation between the dosage of adsorbent and Fe (III) ions removal, with an increase in the adsorbent dose corresponding to higher elimination of Fe (III) ions. Therefore, the Langmuir isotherm model yielded more accurate equilibrium data compared to the Frendulich model. The kinetic data were mostly analyzed using a pseudo-second-order model rather than a pseudo-first-order model. Thermodynamic parameters, including enthalpy (ΔH◦), entropy (ΔS◦), and free energy (ΔG◦), were calculated. The adsorption process was found to be exothermic. Overall, Peganum Harmala was a favorable adsorbent for removing Fe (III) from aqueous solutions.

2

Use of Eichhornia Crassipes as a Bioadsorbent for the Removal of Methyl Orange and Methylene Blue Present in Residual Solutions

Hernández-Origel Carlos David, Patiño-Saldivar Laura, Salazar-Hernández Mercedes, Ardila Alba Nelly, Talavera-López Alfonso, Hernánez-Soto Rosa, Hernández José Alfredo

Journal of Ecological Engineering

|

2022

|

Vol. 23, nr 9

193--211

EN

The textile industry is very important because its products are widely used by society, however, this activity has a great contribution to the contamination of water resources due to its effluents that contain large amounts of colorants, among which is the blue of methylene (MB) and methyl orange (MO) that can cause damage to the health of living being. For this reason the present study concerned the removal of these dyes by adsorption using Eichhornia Crassipes (Water lily) with different treatments. The results show that the chemisorption removal process using two sites per dye molecule having an exothermic nature for the water-treated lily and for the NaOH-treated lily is endothermic. The maximum adsorption capacities of 228.9 mg/g for MB (60 °C) and 155.38 mg/g (30 °C) for MO with the NaOH treatment were achieved. The SEM analysis shows that there are significant changes in the surface due to the treatments. The XRD patterns indicate that with the pretreatment with NaOH the crystallinity of WL increases while the treatment with water maintains the presence of amorphous cellulose. In the FTIR spectra, the bands corresponding to different functional groups such as lignin, cellulose and hemicellulose that participate in the adsorption of both dyes are observed.

3

A novel application of building demolition waste for removal benzene from aqueous solutions

Alquzweeni Saif S., Hassan Afrah A., Alkizwini Rasha S.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

|

2021

|

Vol. 30, No. 1

86--97

EN

A novel application of building demolition waste for removal benzene from aqueous solutions. In this research, demolition waste from buildings has been studied for possible use as benzene removal adsorbent from aquatic solution. The effect of adsorbent dosage, contact time, initial benzene concentration, and initial pH on benzene adsorption capacity have been investigated in the batch adsorption experiments. The adsorption effects initially happened very rapidly and achieved equilibrium within 180 min. Benzene removal was observed to decrease by an increase in the initial concentration of benzene of 300–700 mg·L–1, an increase in the adsorbent dose of 0.4–2.4 g per 100 mL, where an optimum adsorbent dose equal to 1.2 g per 100 mL was found. The potential of adsorption increases with pH 3.0–7.0 to reach the maximum removal efficiency at pH 6.0. The findings showed that equilibrium data were adequately adapted and correlated with the Freundlich isotherm models. The average percentage of the removal at room temperature was about 98%. Results suggest that building demolition waste can be used effectively in industrial wastewater treatment for the removal of aromatic hydrocarbon, benzene, as a low-cost option.

4

Mechanism of the oxidation of nitric oxide with oxygen

Głowiński Józef, Hoffmann Józef, Wilk Marcin

Polish Journal of Chemical Technology

|

2021

|

Vol. 23, nr 1

31--36

EN

Very fast reactions of forming higher nitrogen oxides set out an equilibrium framework for the course of the reaction of nitrogen monoxide oxidation. The slow course of reaction of nitrogen monoxide with oxygen permanently violates the created equilibria. In particular, the equilibrium of the oxidation reaction of nitrogen monoxide with nitrogen dioxide. The contribution of this reaction to the transformation of nitrogen monoxide in the conditions of nitrogen trioxide removal from the gas phase was estimated.

5

The Use of Pre-heated Black Cumin Seeds (Nigella sativa) for Sorption Basic Dyes from Aqueous Solutions

Hassan Afrah Abood, Al-Isawi Rawaa, Saleh Zahra Abd

Journal of Ecological Engineering

|

2021

|

Vol. 22, nr 9

149--158

EN

The discharge of industrial effluents containing dyes such as methylene blue (MB) and safranine T (ST) into water resources has caused serious problems for humans and organisms which live in water. On the other hand, the seeds of nigella sativa have been known to be effective and economical materials that present an excellent performance of dye removal from various types of wastewater. In this study, a different method from the existing literature was used, where the black cumin seeds (HBCS) were heated for a twenty-four hour period at 85 °C and ground to 300 µm particle size to obtain new adsorbents for (MB) and (ST) dye adsorption from aqueous solutions. Four operating variables, which show a strong impact on adsorption, were tested by conducting a batch mode adsorption experiment and these were: the dye solution’s initial pH (pH), the contact time (t), the initial concentration of the dye (Co), and the mass of the adsorbent (ma). The sorption capacity of the adsorbent (q) and the dye removal efficiency (% Rem) were utilized as indicators of the impacts of selected operating variables on adsorption processes. It was found that the adsorption of MB and ST dyes increased when the initial concentration of the solution is higher. The adsorption of MB and ST dyes onto HBCS with initial concentration of 50 mg/L was 3.39 mg/g and 4.36 mg/g, respectively. The equilibrium values for the MB and ST dyes corresponded with the Freundlich isotherm model onto HBCS highlighting the multi-layer adsorption process occurring which describes the interactions between the modified HBCS and the two dyes. The findings demonstrate that the optimum adsorption processes of the MB and ST dyes accrued in the 120 minutes and obtained at pH 10.7 and 11 for MB and ST, respectively. These conditions provide a negative charge for the surface of HBCS, causing its attraction to the positive charge of the MB and ST dyes. Kinetic studies elucidated that the MB and ST dyes adsorption onto HBCS most corresponded with pseudo-second order. The findings of this study could be implemented functionally in the industrial wastewater treatment sector.

6

Analityczne modele eurokodowe i symulacje numeryczne wyboczenia technicznego prętów stalowych

Giżejowski Marian, Wiedro Paweł

Inżynieria i Budownictwo

|

2020

|

R. 76, nr 1-2

41--49

PL

Przedstawiono problematykę oceny nośności przy wyboczeniu technicznym prętów ściskanych, zwichrzeniu prętów zginanych w płaszczyźnie większej bezwładności przekroju oraz wyboczeniu giętno-skrętnym prętów zginanych w płaszczyźnie większej bezwładności przekroju i ściskanych. Przytoczono analityczne modele eurokodowe oraz dokonano identyfikacji zastępczej imperfekcji geometrycznej do budowy imperfekcyjnych modeli numerycznych wyboczenia technicznego. Na przykładzie oceny nośności przy wyboczeniu słupa stalowego porównano różne podejścia analityczne oraz numeryczne.

EN

Problems related to the technical buckling resistance of compressed members, lateral-torsional buckling of members bent in the plane of section greater moment of inertia and flexural-torsional buckling of members compressed and bent in the plane of section greater moment of inertia are presented. Analytical Eurocode models are quoted and equivalent geometric amplitudes to build imperfect numerical models have been identified. Various analytical and numerical approaches were compared on examples of the buckling resistance assessment of a real steel column.

7

Morality, protection, security and gain: lessons from a minimalistic, economically inspired multi-agent model

Komosiński Maciej, Żok Tomasz

Foundations of Computing and Decision Sciences

|

2020

|

Vol. 45, No. 1

17--33

EN

In this work, we introduce a simple multi-agent simulation model with two roles of agents that correspond to moral and immoral attitudes. The model is given explicitly by a set of mathematical equations with continuous variables and is characterized by four parameters: morality, protection, and two efficiency parameters. Agents are free to adjust their roles to maximize individual gains. The model is analyzed theoretically to find conditions for its stability, i.e., the fractions of agents of both roles that lead to an equilibrium in their gains. A multi-agent simulation is also developed to verify the dynamics of the model for all values of morality and protection parameters, and to identify potential discrepancies with the theoretical analysis.

8

Effects of water injection to the fuel and air mixture on equilibrium gas composition in combustion products and selected parameters of the theoretical Otto cycle

Sucheta Andrzej

Combustion Engines

|

2019

|

R. 58, nr 2

95--102

EN

Moisturizing the intake air by spraying water in the liquid phase significantly lowers the intake air temperature, mainly due to the high value of latent heat of evaporation. The paper presents a methodology for calculating the parameters of the air-fuel mixture after water injection and during subsequent processes of the Otto cycle: compression, combustion and expansion of exhaust gases. For octane as a fuel, exemplary calculations have been carried out to investigate the effect of water injection on the composition of combustion products and selected parameters of the theoretical Otto cycle (temperature, pressure, output power and thermal efficiency).

9

Numerical equilibrium analysis of a stack of steel post pallets

Pelc J.

Technical Sciences / University of Warmia and Mazury in Olsztyn

|

2018

|

nr 21(4)

271--280

EN

A method for analyzing the equilibrium of a stack of loaded post pallets is presented. The finite element method was used to investigate the behavior of the bottom pallet in the stack during the addition of successive pallets. The stack was regarded as a self-stable multi-storey structure without bracings which is subjected to the weight of loaded pallets, horizontal forces resulting from sway and bow imperfections, and the impact of a forklift truck. The definite quadratic form of the tangent stiffness matrix after every increment in load was determined by nonlinear analysis to indicate the loss of post stability. An analysis of the stacking process of the evaluated pallets did not reveal a buckling trend in the posts of the bottommost pallet and demonstrated that the loss of equilibrium can lead to the collapse of the entire stack when a critical number of pallets is reached.

10

Artificial neural network approach for modeling of Ni(II) adsorption from aqueous solution by peanut shell

Yildiz S.

Ecological Chemistry and Engineering. S

|

2018

|

Vol. 25, nr 4

581--604

EN

In this study, ANN (artificial neural network) model was applied to estimate the Ni(II) removal efficiency of peanut shell based on batch adsorption tests. The effects of initial pH, metal concentrations, temperature, contact time and sorbent dosage were determined. Also, COD (chemical oxygen demand) was measured to evaluate the possible adverse effects of the sorbent during the tests performed with varying temperature, pH and sorbent dosage. COD was found as 96.21 mg/dm3 at pH 2 and 54.72 mg/dm3 at pH 7. Also, a significant increase in COD value was observed with increasing dosage of the used sorbent. COD was found as 12.48 mg/dm3 after use of 0.05 g sorbent and as 282.78 mg/dm3 after use of 1 g sorbent. During isotherm studies, the highest regression coefficient (R 2) value was obtained with Freundlich isotherm (R 2 = 0.97) for initial concentration and with Temkin isotherm for sorbent dosage. High pseudo-second order kinetic model regression constants were observed (R 2 = 0.95-0.99) during kinetic studies with varying pH values. In addition, Ni(II) ion adsorption on peanut shell was further defined with pseudo-second order kinetic model, since qe values in the second order kinetic equation were very close to the experimental values. The relation between the estimated results of the built ANN model and the experimental results were used to evaluate the success of ANN modeling. Consequently, experimental results of the study were found to be in good agreement with the estimated results of the model.

11

Preparation of bentonite/nAg nanocomposites

Długosz O., Kołodziej M., Banach M.

Composites Theory and Practice

|

2018

|

R. 18, nr 1

7--13

EN

In this work results of the preparation of bentonite/nAg nanocomposites were presented. In the first stage, the bentonite sorption properties were determined, including the equilibrium and kinetics parameters of the sorption process of silver ions on the bentonite. The study analyzed the filler sorption properties for different concentrations of silver ions in solution. The equilibrium sorption data were analyzed using Freundlich, Langmuir and Temkin equations. It was found that the best fit is given by the Freundlich equation. Analysis of the kinetics of the sorption process showed that the pseudo-second-order equation was characterized by the best fit for the experimental data, suggesting the chemical character of the adsorption process. In order to obtain a nanocomposite, silver ions contained in the composite were subjected to a reduction process using tannic acid with stabilizing and reducing properties. The obtained bentonite/nAg nanocomposites contained silver nanoparticles in the range of 162÷266 mg/g. The structures of the nanomaterials were studied by XRD and SEM methods.

PL

Celem niniejszej pracy była analiza równowagi i kinetyki procesu sorpcji jonów srebra na powierzchni napełniacza oraz otrzymanie nanokompozytu bentonit/nAg. W badaniu analizowano właściwości sorpcyjne napełniacza dla różnych stężeń jonów srebra w roztworze. Do opisu równowagi sorpcji analizowanych jonów zastosowano równania Langmuira, Freundlicha oraz Temkina. Stwierdzono, że najlepsze dopasowanie daje równanie Freundlicha. Celem badania było również określenie kinetyki sorpcji. Równanie pseudodrugiego rzędu uzyskało lepsze dopasowanie do danych doświadczalnych, co świadczy o chemicznym charakterze sorpcji. W celu otrzymania nanokompozytu jony srebra zawarte w kompozycie poddano procesowi redukcji przy użyciu kwasu taninowego, charakteryzującego się właściwościami stabilizująco-redukujących. Otrzymano nanokompozyty bentonit/nAg o zawartości nanocząstek srebra 162÷266 mg/g.

12

Gleichgewichte auf den Transport-, Verkehrs- und Logistikmärkten

Witte H.

Problemy Transportu i Logistyki

|

2017

|

nr 2 (38)

15--25

DE

Die traditionelle Interpretation des ökonomischen Gleichgewichts ist nicht erfolgreich bei der Realisierung von Marktgleichgewichten. Das Hauptargument gegen die traditionelle Interpretation des ökonomischen Gleichgewichts ist die normalerweise getroffene Annahme einer unrealistischen reinen Konkurrenz. Eine realistische Idee ist die moderne Interpretation des ökonomischen Gleichgewichts. Diese Interpretation benötigt keine unrealistischen Annahmen und kein hohes mathematisches Verständnis. Die moderne Interpretation des ökonomischen Gleichgewichts führt zu totalen quantitativen und wertorientierten Marktgleichgewichten. Alle drei Teilmärkte (Waren, Geld und Arbeitsmarkt) befinden sich im Gleichgewicht, wenn alle auf diesen Märkten tätigen Wirtschaftseinheiten im Gleichgewicht sind. Der Vorteil der modernen Interpretation des ökonomischen Gleichgewichts ist, dass es keine Utopie, sondern eine „Topia“ ist. Die Erkenntnis führt zur Überwindung von Wirtschaftskrisen und zu einem stetig wachsenden Wohlstand trotz weltweit geringer Ressourcen. Die einzige Bedingung, um die moderne Interpretation des wirtschaftlichen Gleichgewichts zu realisieren, ist der Wille, etwas zu verändern. Es ist möglich, die moderne Interpretation des Gleichgewichts für Transport- und Logistikmärkte zu verwenden.

EN

The traditional interpretation of economic equilibrium is not successful in realizing market equilibria. The main argument against the traditional interpretation of economic equilibrium is the normally made assumption of unrealistic pure competition. A realistic idea is the modern interpretation of economic equilibrium. This interpretation needs no unrealistic assumptions and no high level of mathematic understanding. The modern interpretation of economic equilibrium leads to total quantitative- and valuebased market equilibria. All three partial markets (the goods, the money and the labor market) are in equilibrium, when all economic units acting on these markets are in equilibrium. The advantage of the modern interpretation of economic equilibrium is that it is no utopia but a “topia”. The realization leads to overcome economic crises and to steady growing welfare in spite of worldwide low resources. The only condition to realize the modern interpretation of economic equilibrium is the will to change something. It is possible to use the modern interpretation of equilibrium for transport and logistic markets.

13

Adsorption kinetics of fluoride on bone char and its regeneration

Hu J., Wu D., Rao R., Liu R., Lai W.

Environment Protection Engineering

|

2017

|

Vol. 43, nr 3

93--112

EN

The adsorbent of bone char (BC), produced from the pyrolysis of crushed animal bones, was dominated by the mesopores of the Brunauer Emmett Teller (BET) surface area. The optimal condition for defluoridation with BC was a pH level near 5.0. Chloride and nitrate ions could increase fluoride adsorption capacity in contrast with the effect of sulfate and carbonate ions. The interchangeability between fluoride and hydroxyl groups on BC sorbent was proved by the Fourier transform infrared spectroscopy. Langmuir equation had a better correlation coefficient than the Freundlich equation at various temperatures. Thermodynamic parameters such as Delta G degrees, Delta H degrees, Delta S degrees, Ea and S*, have been calculated to describe the nature of fluoride adsorption onto BC. Negative Delta G degrees and Delta H degrees values at various temperatures indicate a spontaneous process, and its exothermic effect, respectively. However, a positive Delta S degrees value represents an increasing process for entropy. The E-a and S* values ranging from 5 to 40 kj.mol-1 and 0 to 1, respectively, demonstrated that the adsorption is dominated by physical process, although the adsorption kinetic process was involved external diffusion, intraparticle diffusion and chemical reaction equilibrium stage. A high concentration of NaOH solution increases efficiency of removing adsorbed F- ions from the BC surface.

14

Higher-order conditions for local equilibria in a discontinuous Gale economic model

Michalak A., Studniarski M.

Control and Cybernetics

|

2017

|

Vol. 46, no. 1

37--47

EN

The paper introduces the concept of a strict local equilibrium of order k in the Gale economic model. We obtain higher-order necessary and suﬃcient conditions for such equilibria without assuming continuity of the utility functions. These conditions are formulated in terms of generalized lower and upper directional derivatives, introduced by Studniarski (1986). A stability theorem for strict local equilibria of order k is also included.

15

Ergodicity of non-Hamiltonian Equilibrium Systems

Evans D. J., Williams S. R., Rondoni L., Searles D. J.

Computational Methods in Science and Technology

|

2017

|

Vol. 23, No. 3

175--184

EN

It is well known that ergodic theory can be used to formally prove a form of relaxation to microcanonical equilibrium for finite, mixing Hamiltonian systems. In this manuscript we substantially modify this proof using an approach similar to that used in umbrella sampling, and use this approach to consider relaxation in both Hamiltonian and non- Hamiltonian systems. In doing so, we demonstrate the need for a form of ergodic consistency of the initial and final distribution. The approach only applies to relaxation of averages of physical properties and low order probability distribution functions. It does not provide any information about whether the full 6N-dimensional phase space distribution relaxes towards the equilibrium distribution or how long the relaxation of physical averages takes.

16

The Impact of Sustainable Development on the Homeostasis of the Social Environment and the Matter of Survival

Sztumski W.

Problemy Ekorozwoju

|

2016

|

Vol. 11, nr 1

41--47

EN

The survival of social groups depends on internal factors (the size of a group, its socio-diversity, inner organization, coherence and synergy of actions for the common good), external factors, mostly on a safe natural and social environment, and on sustainable interactions with this environment. In addition, the survival and development of groups is determined by their stability, which in turn depends on the homeostatic mechanisms that maintain a state of balance within groups and in their environments. People have an influence on the stability of social systems; their actions may lead to strengthening or weakening of this homeostasis. The implementation of the concept of sustainable development serves, among others, to strengthen the homeostasis of social systems and consequently, to prolong the existence of mankind. However, paradoxically enough, the more the system tends to equilibrium, the less stable it becomes reducing its chance of survival. But still, striving to achieve a state of equilibrium has become an imperative nowadays in view of the concept of sustainable development. Moreover, since the beginning of the Anthropocene era, people's interference in the homeostasis of natural and social systems has been growing, helped by the progress of science and technology. However, only a handful of the world's population, the financial elite, benefit from this. Driven by economic interests and ignoring ecological criteria, they weaken this homeostasis carelessly and irresponsibly. Focused on their own benefits here and now, they do not care much about the fate of future generations.

PL

Przetrwanie grup społecznych zależy od czynników wewnętrznych (liczebności, socjodywergencji, organizacji wewnętrznej, koherencji i synergii działań na rzecz dobra wspólnego), zewnętrznych – przede wszystkim od bezpiecznego środowiska przyrodniczego i społecznego oraz od zrównoważonych interakcji z otoczeniem. Oprócz tego o przetrwaniu i rozwoju decyduje ich stabilność, która zależy od mechanizmów homeostazy zachowujących równowagę w grupach i w środowisku, w jakim przebywają. O homeostazie systemów społecznych decydują ludzie. Ich działania mogą prowadzić do wzmacniania albo do osłabiania homeostazy. Wzmacnianiu homeostazy systemów społecznych, a w konsekwencji ekstensji czasu istnienia ludzkości, służy – między innymi – urzeczywistnianie idei rozwoju zrównoważonego. Tu jednak pojawia się paradoks: im bardziej system zmierza do równowagi, tym mniejszą osiąga stabilność i tym samym zmniejszą swoją szansę na przetrwanie. Nie zważając na to, dążenie do równowagi stało się nakazem chwili za sprawą koncepcji rozwoju zrównoważonego. Poza tym, od początku epoki antropocenu postępuje ingerencja ludzi w homeostazę systemów przyrodniczych i społecznych. A postęp wiedzy i techniki pomaga im w majsterkowaniu przy homeostazie. Korzysta z tego tylko garstka populacji świata – elity finansowe. Nie kierując się kryteriami ekologicznymi, lecz ekonomicznymi, beztrosko i nieodpowiedzialnie osłabiają homeostazę. Mają one na uwadze wyłącznie swoje korzyści osiągane teraz. Dlatego nie obchodzi ich, jaki los szykują wskutek tego przyszłym pokoleniom.

17

Static large games with finitely many types of players and strategies

Wieczorek A.

Prace Instytutu Podstaw Informatyki Polskiej Akademii Nauk

|

2016

|

Nr 1037

1--17

EN

The paper briefly presents a theory of games with finitely many infinite populations (types) each of whom has finitely many available strategies; the payoff of an individual player depends on the distribution of choices of strategies in all populations and his own particular choice. We give specific examples of applications of the theory in several areas: spatial allocation (of species), economic models – household economy and transportation networks. We also briefly discuss questions of computation of equilibria and relations of large games, as understood in the present paper, to ordinary matrix games, games with continuum of players and evolutionary game theory.

PL

Praca zawiera skrótowy opis gier ze skończoną liczbą nieskończonych populacji (typów), z których każda dysponuje skończoną liczbą strategii; wypłata pojedynczego gracza zależy od rozkładu wyborów strategii wszystkich populacji i jego własnego wyboru strategii. Podajemy konkretne przykłady zastosowań w kilku dziedzinach: alokacja przestrzenna (gatunków), modele ekonomiczne – model gospodarki drobnotowarowej i model ruchu drogowego. Dyskutujemy też krótko zagadnienia obliczeniowe i związki dużych gier, jak przedstawiono je w tym artykule, ze zwykłymi grami macierzowymi, grami z continuum graczy i z ewolucyją teorią gier.

18

Comparison the Physico-Chemical Model of Ferrosilicon Smelting Process with Results Observations of the Process under the Industrial Conditions

Machulec B., Bialik W.

Archives of Metallurgy and Materials

|

2016

|

Vol. 61, iss. 1

265--270

EN

Based on the minimum Gibbs Free Enthalpy algorithm (FEM), model of the ferrosilicon smelting process has been presented. It is a system of two closed isothermal reactors: an upper one with a lower temperature T1, and a lower one with a higher temperature T2. Between the reactors and the environment as well as between the reactors inside the system, a periodical exchange of mass occurs at the moments when the equilibrium state is reached. The condensed products of chemical reactions move from the top to the bottom, and the gas phase components move in the opposite direction. It can be assumed that in the model, the Reactor 1 corresponds to the charge zone of submerged arc furnace where heat is released as a result of resistive heating, and the Reactor 2 corresponds to the zones of the furnace where heat is produced by electric arc. Using the model, a series of calculations was performed for the Fe-Si-O-C system and was determined the influence of temperatures T1, T2 on the process. The calculation results show a good agreement model with the real ferrosilicon process. It allows for the determination of the effects of temperature conditions in charge zones and arc zones of the ferrosilicon furnace on the carbothermic silica reduction process. This allows for an explanation of many characteristic states in the ferrosilicon smelting process.

19

Model stref reakcyjnych w piecu żelazokrzemowym rezystancyjno-łukowym

Machulec B.

Hutnik, Wiadomości Hutnicze

|

2015

|

Vol. 82, nr 12

751--755

PL

Bazując na algorytmie minimalizacji Gibbsa przedstawiono model fizykochemiczny procesu wytopu żelazokrzemu. Modelem procesu jest układ dwóch reaktorów izotermicznych: górnego o temperaturze niższej T1, oraz dolnego o temperaturze wyższej T2 . Pomiędzy reaktorami i otoczeniem, oraz pomiędzy reaktorami wewnątrz układu zachodzi cyklicznie wymiana masy w chwilach, gdy w reaktorach osiągnięty jest stan równowagi. Skondensowane produkty reakcji przechodzą z góry w dół, a składniki fazy gazowej w kierunku przeciwnym. Można założyć, że reaktor 1 odpowiada strefom pieca rezystancyjno-łukowego w których ciepło wydziela się na zasadzie nagrzewania rezystancyjnego, a strefa 2 odpowiada strefom łuku, w których ciepło wydziela się na zasadzie nagrzewania łukowego. Wykorzystując pakiet do obliczeń termochemicznych HSC 7.1 przeprowadzono serię obliczeń symulacyjnych dla układu Fe-Si-O-C oraz określono wpływ temperatury T1, T2 na efektywność procesu redukcji krzemionki węglem.

EN

Based on the minimum Gibbs Free Enthalpy algorithm, model of the ferrosilicon smelting process has been presented. It is a system of two closed isothermal reactors: an upper one with a lower temperature T1, and a lower one with a higher temperature T2. Between the reactors and the environment as well as between the reactors inside the system, a periodical exchange of mass occurs at the moments when the equilibrium state is reached. The condensed products of chemical reactions move from the top to the bottom, and the gas phase components move in the opposite direction. It can be assumed that in the model, the Reactor 1 corresponds to the charge zone of submerged arc furnace where heat is released as a result of resistive heating, and the Reactor 2 corresponds to the zones of the furnace where heat is produced by electric arc. Using the model, a series of calculations was performed for the Fe-Si-O-C system and was determined the influence of temperatures T1, T2 on the efficiency of the carbothermic silica reduction process.

20

Wpływ wzbogacania tlenem zubożonego powietrza na równowagowy skład spalin oraz wybrane parametry teoretycznego cyklu Otto

Sucheta A.

Combustion Engines

|

2015

|

R. 54, nr 3

532--539

PL

W pracy poddano analizie pojazd ratowniczy przystosowany do pracy w zubożonym powietrzu, którego układ zasilania powietrzem został zaopatrzony w zbiornik tlenu i mieszalnik zapewniający utrzymanie koncentracji tlenu 21% w gazowej mieszaninie utleniającej doprowadzanej do silnika. Została podana metodyka wyznaczania składu równowagowego spalin w przemianie ekspansji powstałych ze spalania paliwa o składzie CαHβOγNδ w gazowej mieszaninie utleniającej o znanym składzie. Przedstawiono wyniki przykładowych obliczeń wybranych parametrów teoretycznego obiegu Otto dla metanu jako paliwa, zadanego współczynnika stechiometrycznego w zależności od składu mieszaniny utleniającej.

EN

The study analyzed the rescue vehicle designed to temporary work in depleted air, which the air supply system was equipped with an oxygen pressure vessel and mixer to maintain an oxygen concentration of 21% in the oxidizing gas mixture supplied to the engine. Was given the methodology for determining the equilibrium combustion products composition (in the expansion stroke) resulting from the combustion of fuel CαHβOγNδ in the gas oxidation mixture of known composition. Paper presents the results of sample calculations of selected parameters of the theoretical Otto cycle for the methane as fuel, depending on the composition of the oxidation mixture and the given equivalence ratio.