Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "kinetic parameters" wg kryterium: Temat


Tytuł:
STABILITY STUDIES OF CEFTIOFUR SODIUM IN AQUEOUS SOLUTIONS AND IN THE SOLID PHASE
Autorzy:
Dołhań, Agnieszka
Sobczak, Agnieszka
Muszalska, Izabela
Medenecka, Beata
Garbacki, Piotr
Tomczak, Szymon
Jelińska, Anna
Powiązania:
https://bibliotekanauki.pl/articles/895368.pdf
Data publikacji:
2018-12-31
Wydawca:
Polskie Towarzystwo Farmaceutyczne
Tematy:
stability
kinetic parameters
thermodynamic parameters
solid phase
Opis:
Ceftiofur sodium (CFT), a third-generation cephalosporin for parenteral use, is commonly used in veterinary medicine against aerobic Gram-positive and Gram-negative bacteria as well as certain anaerobes. Its broad spectrum of activity and resistance to beta-lactamases result from the presence of methoxyimino and aminothiazole moieties at C-7 in the cephalosporin structure. The aim of this study was a comprehensive evaluation of the stability of CFT in the solid phase and in aqueous solutions. A fast and sensitive HPLC isocratic method was used for the determination of CFT degradation in the solid phase and in aqueous solutions. CFT degradation occurred according to a first-order reaction depending on the substrate concentration. The kinetic and thermodynamic parameters of CFT degradation in the solid phase were calculated. General acid-base hydrolysis of CFT was not observed in the solutions of hydrochloric acid, sodium hydroxide, phosphate (pH 5.84 – 7.25), acetate (pH 3.65 – 5.48) and borate (pH 7.49 – 10.07) buffers. CFT was the most stable in the pH range 2 – 6. The susceptibility of CFT to degradation under the influence of stress factors (pH, temperature, buffer components concentration, relative air humidity) should be considered in terms of storage conditions and the preparation of the product for administration.
Źródło:
Acta Poloniae Pharmaceutica - Drug Research; 2018, 75, 6; 1279-1286
0001-6837
2353-5288
Pojawia się w:
Acta Poloniae Pharmaceutica - Drug Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Partial characterization of proteases from Citrus sinensis fruit peel
Autorzy:
Ibraheem, Ademola Saheed
Malomo, Silvia O.
Powiązania:
https://bibliotekanauki.pl/articles/1178685.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Citrus sinensis
Proteases
industries
kinetic parameters
Opis:
Proteases are one of the most important enzymes that have various physiological and industrial applications. This study was carried out to purify and partially characterize proteases from Citrus sinensis fruit peel. Three active fractions of the proteases (I, II and III) were obtained. The Vmax for proteases I, II, III and pooled fraction were 185.19, 192.31, 111.11 and 163.93 U/ml with Michaelis-Menten’s constant (Km) 1.01, 0.44, 0.67 and 0.37 mg/ml respectively. The enzymes were optimally active at 40-50 °C. However, they retained activity at 60-70 °C. Protease I was stable up to 60 °C while proteases II and III retained more than 80% activity in the range of 25-70 °C. The optimal pH of proteases II and III was 7 while protease I was optimally active at pH 8. The enzymes were stable at alkaline pH especially between 6 and 9 retaining more than 60% of its activity. The stability of these enzymes at high temperature and different pH may be an indication of its potential applications in food, chemical and laundry industries.
Źródło:
World Scientific News; 2017, 67, 2; 250-264
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption and inhibitive properties of methanol extract of Eeuphorbia Heterophylla for the corrosion of copper in 0.5 M nitric acid solutions
Autorzy:
Fouda, A. S.
Elmorsi, M. A.
Abou-Elmagd, B. S.
Powiązania:
https://bibliotekanauki.pl/articles/780024.pdf
Data publikacji:
2017
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
acid corrosion
copper
green inhibitor
adsorption
kinetic parameters
Opis:
The adsorption and the inhibitive properties of methanol extract of Euphorbia heterophylla on copper in 0.5 M HNO3  have been studied by weight loss method at different temperatures (30-50°C), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. Also, the surface morphology was analyzed by scanning electron microscopy (SEM). It was found that the inhibition efficiency increases with increasing extract doses and decreased with increasing temperature. The polarization data revealed that this extract acts as mixed type inhibitor. The adsorption process was more favored at lower temperatures with larger negative standard free energy. The extract was adsorbed physically on the copper surface followed Frumkin isotherm.
Źródło:
Polish Journal of Chemical Technology; 2017, 19, 1; 95-103
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, spectral and thermal study of (2E, 6E) 2,6-bis(4-hydroxy benzylidene)-4-R-cyclohexanone
Autorzy:
Sankhavara, Dharmesh B.
Chopda, Jalpa V.
Patel, Jignesh P.
Parsania, P. H.
Powiązania:
https://bibliotekanauki.pl/articles/1070865.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Chalcone
bisphenol
heat of melting
kinetic parameters
thermal stability
Opis:
(2E,6E) 2,6-Bis(4-hydroxybenzalidene)-4-R-cyclohexanone (BHBC, R = H and MBHBC, R = CH3) was synthesized by condensing cyclohexanone/4-methylcyclohexanone with 4-hydroxy benzaldehyde using mixture of boric acid and hydrochloric acid as a catalyst at 60-70 ºC for 1 h. The structures of BHBC and MBHBC are supported by FTIR, 1HNMR, 13CNMR and MS techniques. DSC endothermic transition at 282.48 ºC (BHBC) and two endothermic transitions at 214.66 and 224.83 ºC and assigned as melting transitions. The compositions of the two isomers of MBHBC were determined from their corresponding peak areas and observed compositions are 81.5% and 18.5%, respectively for Isomer-I and Isomer-II. BHBC and MBHBC are thermally stable up to 305 ºC and 285 ºC, respectively and followed three step degradation kinetics. Both the compounds followed apparently first order degradation kinetics and were completely degraded into low molecular mass hydrocarbons.
Źródło:
World Scientific News; 2019, 123; 141-160
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temperature influence on the electrode process in the presence of 6-thioguanine and surfactants
Autorzy:
Nosal-Wiercińska, Agnieszka
Kaliszczak, Waldemar
Martyna, Marlena
Szabelska, Anna
Gołębiowska, Beata
Wiśniewska, Małgorzata
Powiązania:
https://bibliotekanauki.pl/articles/1845199.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
catalytic effect
Bi(III) electroreduction
6-thioguanine
surfactants
thermodynamic parameters
kinetic parameters
Opis:
The measurements concerning the process of the electroreduction of Bi(III) ions in the presence of 6–thioguanine (6TG) and Triton X-100 as well as Tween 80 in the 2 $mol·dm^{-3}$ chlorates(VII) demonstrate a dependence of the process rate on temperature. The applied electrochemical techniques (DC polarography, cyclic and SWV voltammetry) allowed to determine the kinetic and thermodynamic parameters as well as their correlation with changes in kinetics of the electrode process. The catalytic activity of 6TG was confirmed by the decrease of overall enthalpies of activation. Different values of $\DeltaH^{\ne}$ and $\DeltaS^0$ for Bi(III) electroreduction in the presence of 6–thioguanine as well as Triton X-100 and Tween 80 suggest changes in kinetics of the electrode process towards inhibition.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 6; 14-21
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Metal Oxides on the Thermal Decomposition Kinetics and Mechanisms of HAN/PVA Based Propellants
Autorzy:
Hu, Song-qi
Liu, Xue-li
Liu, Lin-Lin
Kang, Bo
Zhang, Yan
Powiązania:
https://bibliotekanauki.pl/articles/27787991.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HAN/PVA-based propellant
metal oxides
catalytic behaviour
kinetic parameters
Opis:
The thermal decomposition processes of HAN/PVA-based propellants have been investigated using a simultaneous thermogravimetric analysis (TGA) – differential scanning calorimetry (DSC), coupled with Fourier-Transform Infrared Spectroscopy (FTIR) and Mass Spectrometry (MS) system. The activation energy (Ea), pre-exponential factor A and reaction mechanism function f(α) of the decomposition processes have been determined by non-isothermal and Malek methods. The results showed that the decomposition process of an HAN/PVA sample occurs mainly in the temperature range 202.2~220.1 °C, with a mass loss, heat release and Ea of about 84.8%, 1474.18 and 88.76 kJ·mol–1, respectively. Of the seven metal oxides studied as catalysts, Al2O3, V2O5 and Fe2O3 have significant catalytic effects on an HAN/PVA-based propellant, in lowering the decomposition temperature, with Ea changing from 88.8 to 83.7, 85.6 and 113.6 kJ·mol–1, respectively. The f(α) of both HAN/PVA and HAN/PVA/Al2O3 samples can be expressed as f(α) = (1 – α)2, whereas f(α) = α or f(α) = α/2 fit well for the HAN/PVA/V2O5 and HAN/PVA/Fe2O3 samples.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 3; 322-338
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Establishment of constitutive model and dynamic parameter analysis of rubber conveyor belt
Autorzy:
Chen, Hongyue
Liu, Siyuan
Powiązania:
https://bibliotekanauki.pl/articles/2200896.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
rubber conveyor belt
wire rope core
kinetic parameters
fitting curve
mathematical model
Opis:
A rubber conveyor belt is an essential piece of equipment in coal mine transportation. Its current motion and performance are directly affected by dynamic parameters. In this paper, a constitutive model has been established to study a rubber conveyor belt in order to analyze its dynamic characteristics. The covered rubber was considered as a classical solid model. The wire rope core was used as a Kelvin model, and a generalized constitutive mathematical model was established. Using Matlab, compariso of the fitting curve and the experimental curve was carried out to ensure reliability in an appropriate way. Meanwhile, the influence of different factors on dynamic parameters of rubber conveyor belts was also discussed by controlling the loading frequency and amplitude as well as external temperature. Finally, the experiment with the fitting curve was compared and verified, and the research results can provide a reference for this engineering field.
Źródło:
Journal of Theoretical and Applied Mechanics; 2023, 61, 2; 365--378
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of hydrous-pyrolysis kinetic parameters for oil generation from Baltic Cambrian and Tremadocian source rocks with Type-II kerogen
Autorzy:
Więcław, D.
Kotarba, M. J.
Lewan, M. D.
Powiązania:
https://bibliotekanauki.pl/articles/2059067.pdf
Data publikacji:
2010
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Baltic Region
Cambrian
Ordovician
hydrous pyrolysis
organic sulfur
kinetic parameters
type II kerogen
Opis:
Determining kinetic parameters for oil generation from a source rock by hydrous pyrolysis requires a considerable amount of sample (kilograms) and laboratory time (several weeks). In an effort to circumvent these requirements, hydrous-pyrolysis (HP) kinetic parameters for oil generation from Upper Cambrian and Tremadocian source rocks of the Baltic region are estimated by two methods: (1) organic sulfur content in kerogen and (2) HP experiments conducted at 330 and 355°C for 72 h. Estimates for the Upper Cambrian source rocks based on organic sulfur contents gave activation energies from 47 to 56 kcal/mole and frequency factors from 1.156 ' 1025>/sup> to 1.078 ' 1028 m.y.-1 . Tremadocian source rocks based on organic sulfur content gave estimated activation energies from 60 to 62 kcal/mole and frequency factors from 1.790 ' 1029 to 1.104 ' 1030 m.y.-1 . The estimates for the Tremadocian source rocks were less affected by thermal maturation because their low kerogen S/(S + C) mole fractions (< 0.018) remained essentially constant. Conversely, the higher kerogen S/(S + C) mole fractions (>>gt; 0.018) of the Upper Cambrian source rocks decreased with thermal maturation and resulted in overestimation of the kinetic parameters. The second method was designed to estimate kinetic parameters based on two HP experiments. The assumption that the maximum yield in calculating the rate constant at 330°C (k330°C could be determined by a second hydrous pyrolysis experiment at 355°C for 72 h proved not to be valid. Instead, a previously established relationship between Rock-Eval hydrogen index and maximum HP yield for Type-II kerogen was used to calculate k330°C from oil yields generated by the HP experiment at 330°C for 72 h assuming a first-order reaction. HP kinetic parameters were determined from relationships between k330°C and the HP kinetic parameters previously reported. These estimated HP kinetic parameters were in agreement with those obtained by the first method for immature samples, but underestimated the kinetic parameters for samples at higher thermal maturities. Applying these estimated HP kinetic parameters to geological heating rates of 1 and 10°C/m.y. indicated that the Upper Cambrian source rocks would generate oil notably earlier than the overlying Tremadocian source rocks. This was confirmed in part by available data from two neighboring boreholes in the Polish sector of the Baltic.
Źródło:
Geological Quarterly; 2010, 54, 2; 217-226
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and thermal decomposition kinetics of some pyrazolo-quinazoline derivatives
Autorzy:
Baluja, Shipra
Nandha, Kajal
Powiązania:
https://bibliotekanauki.pl/articles/1193006.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Pyrazolo-quinazolines
chalcones
differential scanning calorimetry
kinetic parameters
thermal gravimetric analysis
thermal stability
Opis:
Some new pyrazolo-quinazolines have been synthesized and characterization of the synthesized was done by IR, NMR and mass spectral data. The thermal properties of some synthesized compounds were studied by TGA and DSC methods. From the thermo grams, thermal stability and some kinetic parameters such as energy of activation, frequency factor, order of reaction and entropy of activation were evaluated. It is observed that for all the studied compounds, degradation is single step process. Thermal stability varies slightly according to the nature and position of the substitutions present in the studied compounds.
Źródło:
World Scientific News; 2016, 31; 100-110
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Treatment of milk wastewater using up-flow anaerobic packed bed reactor
Autorzy:
Bhuyar, K. D.
Suke, S. G.
Dawande, S. D.
Powiązania:
https://bibliotekanauki.pl/articles/778799.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Up-flow anaerobic packed-bed reactor
milk wastewater
kinetic parameters
hydraulic retention times
biogas
Opis:
An up-flow anaerobic packed bed (UAPB) bioreactor has been designed on a laboratory-scale and used for treatment of domestic milk wastewater (MWW). The UAPB bioreactor was operated under mesophilic temperature (37-45°C) and reactor performance evaluated at various organic loading rates of MWW effluent at hydraulic retention times (HRT) of 1, 2, and 3 d based on the removal of organic matter COD, BOD, SS, pH changes and biogas production. The kinetic parameters were estimated using the experimental data to develop a reactor model. Empirical relations were generated for the characteristics like COD, BOD, and SS using modeling equations. This study proved that the UAPB reactor performance is excellent for treating domestic MWW and easily biodegradable dairy wastewater influent. Hence, this system can operate at low costs, making it suited for use in the developing countries and rural areas.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 2; 84-88
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of kinetic parameters of coal pyrolysis to simulate the process of underground coal gasification (UCG)
Autorzy:
Urych, B.
Powiązania:
https://bibliotekanauki.pl/articles/92059.pdf
Data publikacji:
2014
Wydawca:
Główny Instytut Górnictwa
Tematy:
underground coal gasification
pyrolysis
thermogravimetric analysis
kinetic parameters
podziemne zgazowanie węgla
piroliza
analiza termograwimetryczna
parametry kinetyczne
Opis:
Purpose The aim of the research presented in this paper was to determine the values of the kinetic parameters of coal pyrolysis from two areas of the planned experiment, UCG, i.e. the Barbara Experimental Mine of the Central Mining Institute and the Wieczorek Mine. Methods The thermal decomposition of coal analysis used the thermogravimetric technique. The test was carried out in a temperature range of 298-1173 K in a nitrogen atmosphere for three fixed heating rates, β – 5, 10, and 15 K/min. A selection of sample heating rates of coal and reaction environments were designed to reflect the conditions seen during the process of underground coal gasification. The kinetic parameters were determined by using modified Coats-Redfern, Kissinger and Mianowski-Radko methods. Results The values of the activation energy, E, and the pre-exponential factor, A, were determined for a given model of the first order decomposition reaction of coal. The study successfully compared kinetic parameters of the tested coals. Practical implications Designated kinetic parameters may be used to model the process of pyrolysis and – as preliminary data – for installation design of pilot underground coal gasification. Originality/ value The devolatilization of a homogenous lump of coal is a complex issue. Currently, the CFD technique (Computational Fluid Dynamics) is commonly used for the multi-dimensional and multiphase phenomena modelling. The mathematical models, describing the kinetics of the decomposition of coal, proposed in the article can, therefore, be an integral part of models based on numerical fluid mechanics.
Źródło:
Journal of Sustainable Mining; 2014, 13, 1; 3-9
2300-1364
2300-3960
Pojawia się w:
Journal of Sustainable Mining
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A numerical approach to predict sulphur dioxide emissions during switchgrass combustion
Autorzy:
Peters, B.
Smuła-Ostaszewska, J.
Powiązania:
https://bibliotekanauki.pl/articles/185309.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biomass combustion
sulphur dioxide emissions
kinetic parameters
optimization
spalanie biomasy
emisja dwutlenku siarki
parametry kinetyczne
optymalizacja
Opis:
The demand for a net reduction of carbon dioxide and restrictions on energy efficiency make thermal conversion of biomass a very attractive alternative for energy production. However, sulphur dioxide emissions are of major environmental concern and may lead to an increased corrosion rate of boilers in the absence of sulfatation reactions. Therefore, the objective of the present study is to evaluate the kinetics of formation of sulphur dioxide during switchgrass combustion. Experimental data that records the combustion process and the emission formation versus time, carried out by the National Renewable Energy Institute in Colorado (US), was used to evaluate the kinetic data. The combustion of switchgrass is described sufficiently accurate by the Discrete Particle Method (DPM). It predicts all major processes such as heating-up, pyrolysis, combustion of switchgrass by solving the differential conservation equations for mass and energy. The formation reactions of sulphur dioxide are approximated by an Arrhenius-like expression including a pre-exponential factor and an activation energy. Thus, the results predicted by the Discrete Particle Method were compared to measurements and the kinetic parameters were subsequently corrected by the least square method until the deviation between measurements and predictions was minimised. The determined kinetic data yielded good agreement between experimental data and predictions.
Źródło:
Chemical and Process Engineering; 2013, 34, 1; 121-137
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal properties of modified single-base propellants
Właściwości termiczne modyfikowanych prochów jednobazowych
Autorzy:
Gańczyk-Specjalska, Katarzyna
Cieślak, Katarzyna
Zembrzucka, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/27787730.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
modified propellants
nitrocellulose propellants
thermal properties
kinetic parameters
prochy modyfikowane
proch nitrocelulozowy
właściwości termiczne
parametry kinetyczne
Opis:
The paper outlines the influence of various plasticizers (centralit I, nitroglycerine and diethylene glycol dinitrate) on the thermal properties of single-base propellants. Simultaneous differential scanning calorimetry and thermogravimetric analysis were used for this research. The basic physicochemical properties of the tested propellants were also determined, such as: geometric parameters, density and dynamic vivacity. Modifiers of the combustible layer were introduced into the pores of the nitrocellulose, based on the geometrical parameters of the propellants. The entire combustible powder layer was modified when the process was carried out in ethanol. All the modifiers used influenced the dependence of dynamic vivacity on the conversion degree. The use of 12.6 phr (part per 100 parts of propellant) of liquid nitroesters or ethanol as a dispersing medium causes a change in the propellants decomposition mechanism, which is related to a change in the structure of nitrocellulose.
W pracy przedstawiono wpływ różnych plastyfikatorów (centralit I, nitrogliceryna i diazotan glikolu dietylenowego) na właściwości termiczne prochów jednobazowych. Do badań wykorzystano jednoczesną analizę skaningowej kalorymetrii różnicowej i termograwimetryczną. Określono również podstawowe właściwości fizykochemiczne badanych prochów takie jak: parametry geometryczne, gęstość i żywość dynamiczną. Modyfikatory warstwy palnej zostały wprowadzone do porów nitrocelulozy, co stwierdzono na podstawie parametrów geometrycznych prochów. Przeprowadzenie procesu w etanolu powoduje zmodyfikowanie całej warstwy palnej prochu. Wszystkie zastosowane modyfikatory wpłynęły na zależność żywości dynamicznej od stopnia przereagowania. Zastosowanie 12,6 phr (część na 100 części paliwa) ciekłych nitroestrów lub etanolu jako medium rozpraszającego powoduje zmianę mechanizmu rozkładu prochów, co związane jest ze zmianą struktury nitrocelulozy.
Źródło:
Materiały Wysokoenergetyczne; 2021, 13; 59--69
2083-0165
Pojawia się w:
Materiały Wysokoenergetyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sorption kinetics of Cd(II) ions on fermented grape marc
Autorzy:
Grudić, V.
Bošković, I.
Jaćimović, Z.
Powiązania:
https://bibliotekanauki.pl/articles/207276.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
activated carbon
cadmium compounds
kinetic parameters
Weber-Morris model
węgiel aktywny
związki kadmu
parametry kinetyczne
model Webera-Morrisona
Opis:
The sorption kinetics of Cd(II) ions on the biosorbent which is waste in wine production has been investigated. The sorption process took place relatively quickly, enabling one to achieve equilibrium within a period of 15–20 min only, depending on initial concentration of the sorbate. Kinetic models of pseudo-first and pseudo-second order, model of diffusion in a fluid film and Weber’s and Morris’ intraparticle diffusion model were used to describe the experimental results. The pseudo-second order kinetic model described the sorption process with a high correlation coefficient (R2 = 0.998) better than the other kinetic models. The mass transfer coefficient decreases upon increasing the initial concentration of the solution, which can be explained by the fact that the mechanism of binding of Cd(II) ions to the surface of the sorbent is ion exchange followed by discharge of exchangeable cations from the surface. Characteristic constants in the Weber–Morris model increase upon increasing the initial concentration of the solution.
Źródło:
Environment Protection Engineering; 2017, 43, 4; 243-252
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coal Char Kinetics of Oxidation and Gasification Reactions
Autorzy:
Lewtak, R.
Hercog, J.
Powiązania:
https://bibliotekanauki.pl/articles/185256.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
kinetic parameters
char particle oxidation and gasification
oxy-fuel combustion
parametry kinetyczne
utlenianie cząstek stałych
spalanie tlenowo-paliwowe
Opis:
Experimental investigations and numerical simulations have been conducted in this study to derive and test the values of kinetic parameters describing oxidation and gasification reactions between char carbon and O2 and CO2 occurring at standard air and oxy-fuel combustion conditions. Experiments were carried out in an electrically heated drop-tube at heating rates comparable to fullscale pulverized fuel combustion chambers. Values of the kinetic parameters, obtained by minimization of the difference between the experimental and modeled values of char burnout, have been derived and CFD simulations reproducing the experimental conditions of the drop tube furnace confirmed proper agreement between numerical and experimental char burnout.
Źródło:
Chemical and Process Engineering; 2017, 38, 1; 135-145
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies