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Volume 14 (2012): Issue 4 (December 2012)

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Journal Details
Format
Journal
eISSN
1899-4741
ISSN
1509-8117
First Published
03 Jul 2007
Publication timeframe
4 times per year
Languages
English

Search

Volume 14 (2012): Issue 4 (December 2012)

Journal Details
Format
Journal
eISSN
1899-4741
ISSN
1509-8117
First Published
03 Jul 2007
Publication timeframe
4 times per year
Languages
English

Search

18 Articles
Open Access

The utilization possibility of waste lignite as a raw material in the process of obtaining humic acids preparations

Published Online: 12 Jan 2013
Page range: 1 - 6

Abstract

Abstract

In the light of environmental law utilization lignite waste in non-energy sectors of the economy is a rational way to manage them. Lignite due to the lower degree of coalification and calorific value as well as a high content of humic substances becomes a valuable component of fertilizer. The paper presents the possibility of using lignite waste as a raw material in the process of obtaining humic acids with 0.1 M NaOH. The idea of the process combines production, environmental and economic purposes. After the extraction process of humic acids and considering the possibility of using waste formed during the process, were carried out a number of studies to assist in choosing the best solution to its management.

Keywords

  • brown coals
  • humic acids
  • extraction
  • alkaline w
Open Access

Application of the side stream from the cyklopol process in paint stripping formulations

Published Online: 12 Jan 2013
Page range: 7 - 10

Abstract

Abstract

The utilization of two side streams from the Cyklopol process was studied. The first one is the monohydric alcohols fraction and the second one is the fraction of mono-carboxylic acids. We propose to utilize these fractions and their esters as a component of gel formulation painting remover. Our composites have a gel formulation suitable for easy application on a vertical surface. D-DBS (1,3:2,4-Di-O-benzylidene-Dsorbitol) or MHPC (methylhydroxypropylcellulose) were used as gelling agents for organic liquids. The D-DBS compound is characterized by transparency and reduced yellowing of composition. The properties of the obtained preparations were compared to the properties of commercially available gel formulations SCANSOL and STRIPER. Our initial investigations indicate that side streams from the Cyklopol process are good and cheap resources of raw materials for the preparation of paint stripping formulations.

Keywords

  • Cyklopol
  • side stream
  • paint removing
  • gel formulation.
Open Access

Recycling of styrofoam waste: synthesis, characterization and application of novel phenyl thiosemicarbazone surface

Published Online: 12 Jan 2013
Page range: 11 - 18

Abstract

Abstract

An attempt has been made to recycle Styrofoam waste to a novel functional polymer, Phenyl thiosemicarbazone surface (PTS). Polystyrene (PS) obtained from Styrofoam waste was acetylated and then condensed to PTS by reacting it with 4-Phenyl-3-thiosemicarbazide ligand and characterized by FT-IR spectroscopy and elemental analysis. Synthesized PTS was applied successfully for the treatment of lead contaminated water by batch extraction method. Sorption variables were optimized (pH 8, adsorbent dose 53mg, initial Pb(II) ion concentration 10mgl-1 and agitation time 90min) by factorial design approach. Lead uptake by PTS was found much sensitive to the pH of Pb(II) ion solution. The maximum removal (99.61%) of Pb(II) ions was achieved at optimum conditions. The Langmuir and D-R isotherm study suggested the monolayer, favorable (RL=0.0001-0.01) and chemisorption (E=20.41±0.12kJmol-1) nature of the adsorption process. The sorption capacity of PTS was found to be 45.25±0.69mgg-1. The FT-IR spectroscopy study showed the involvement of nitrogen and sulphur of thiosemicarbazone moiety of PTS for the uptake of Pb(II) ions by five membered chelate formation.

Keywords

  • Recycling
  • Styrofoam
  • Functional polymer
  • Pb(II) ion removal
  • Phenyl thiosemicarbazone surface
  • Factorial Design Approach.
Open Access

Bromine catalyst for the methane to methyl bisulfate reaction

Published Online: 12 Jan 2013
Page range: 19 - 21

Abstract

Abstract

A catalytic system KBr - oleum is effective at catalyzing the selective oxidation of methane to methanol via. methyl bisulfate. The influences of methane pressure, sulfur trioxide and temperature on turnover frequency were investigated.

Keywords

  • methane
  • methyl bisulfate
  • methanol
  • KBr
Open Access

Development of approach to modelling and optimization of non-stationary catalytic processes in oil refining and petrochemistry

Published Online: 12 Jan 2013
Page range: 22 - 29

Abstract

Abstract

An approach to modelling of non-stationary catalytic processes of oil refining and petrochemistry is proposed. The computer modelling systems under development take into account the physical and chemical reaction laws, raw materials composition, and catalyst nature. This allows using the software for the optimization of process conditions and equipment design. The models created can be applied for solving complex problems of chemical reactors design; calculation of different variants of industrial plants reconstruction; refining and petrochemicals catalysts selection and testing; catalyst service life prolongation; determination of optimum water supply into the alkanes dehydrogenation reactor; optimization of products separation in the benzene alkylation process.

Keywords

  • oil refining
  • mathematical model
  • non-stationary
  • technological mode
  • forecasting.
Open Access

Surface active agent production from olive oil in high salt conditions and its process optimization

Published Online: 12 Jan 2013
Page range: 30 - 34

Abstract

Abstract

Microbial surfactants or biosurfactants are surface active amphiphilic macromolecules that are produced by a number of microorganisms (bacteria, yeast and fungi). These compounds have extensive application in various industries especially in food, pharmaceutical and oil industry. The aim of this paper is to optimize the culture conditions for the biosurfactant production from olive oil by a novel halophilic isolate microorganism. The Taguchi experimental design methodology based analysis of olive oil as carbon source, yeast extract as nitrogen source and KH2PO4 as phosphorus source revealed that the olive oil and yeast extract significantly affect biosurfactant production in high salt conditions. Maximum biosurfactant (E24= 40%) produced in the presence of 4% (v/v) olive oil, 0.2% (w/v) yeast extract, and 0.002% (w/v) KH2PO4 . In conclusion, halophilic archaeon Haloarcula sp. IRU1 could be a potential microorganism for the production of biosurfactant from olive oil as carbon source in high salt conditions. The optimal parameters obtained during the optimization process were: olive oil 4%, yeast extract 0.4% and KH2PO4 0.004%.

Keywords

  • Surface active agent
  • Olive oil
  • optimization
  • Taguchi experimental design methodology.
Open Access

Meso-tetraphenylporphyriniron(iii) chloride catalyzed oxidation of aniline and its substituents by magnesium monoperoxyphthalate in aqueous acetic acid medium

Published Online: 12 Jan 2013
Page range: 35 - 41

Abstract

Abstract

The catalytic properties of the first generation catalyst meso-tetraphenylporphyriniron(III) chloride and magnesium monoperoxyphthalate (MMPP) as oxidant have been studied in the oxidation of aniline and its substituents in acetic acid medium. The thermodynamic parameters for the oxidation have been determined and discussed. It confirms the Exner relationship (only at the low range of temperatures) and also some of the activation parameters to the isokinetic relationships. The magnesium monoperoxyphthalate oxidation with 18 ortho- meta- and para-substituted anilines fulfills with isokinetic relationship but not to any of the linear free energy relationships. The reaction mechanism and the rate law were proposed.

Keywords

  • Aniline oxidation
  • kinetics
  • mechanism
  • magnesium monoperoxyphthalate
  • mesotetraphenylporphyriniron( III) chloride
  • catalyst.
Open Access

Liquid-solid interaction during formation of nanocomposite systems

Published Online: 12 Jan 2013
Page range: 42 - 45

Abstract

Abstract

Structural changes in mixtures of liquid Bi with small Cu and Ni particles were studied at temperatures of 615 and 1145K. Microstructures of the composites were observed (SEM) and analyzed after treatment at different temperatures and various durations of stirring. The structure of the mixtures of Bi with Cu(Ni) particles was investigated by means of X-ray diffraction, both in the solid and liquid state.

Keywords

  • composite materials
  • liquid metals and alloys
  • metallic powders
  • microstructure
  • short-range order.
Open Access

Artificial neural network to predict the natural convection from vertical and inclined arrays of horizontal cylinders

Published Online: 12 Jan 2013
Page range: 46 - 52

Abstract

Abstract

The main focus of the present study is to utilize the artificial neural network (ANN) in predicting the natural convection from horizontal isothermal cylinders arranged in vertical and inclined arrays. The effects of the vertical separation spacing to the cylinder diameter ratio (Py/d), horizontal separation spacing to the cylinder diameter ratio (Px/d) and Rayleigh number (Ra) variation on the average heat transfer from the arrays are considered via this prediction. The training data for optimizing the ANN structure is based on available experimental data. The Levenberg-Marquardt back propagation algorithm is used for ANN training. The proposed ANN is developed using MATLAB functions. For the best ANN structure obtained in this investigation, the mean relative errors of 0.027% and 0.482% were reached for the training and test data, respectively. The results show that the predicted values are very close to the experimental ones.

Keywords

  • Natural Convection
  • Inclined Array
  • Vertical Array
  • Modeling
  • Artificial Neural Network.
Open Access

Fly ash as the component of composites materials

Published Online: 12 Jan 2013
Page range: 53 - 56

Abstract

Abstract

The fly ash from powerplant can be compared, due to its genesis, chemical and mineralogical composition with the natural volcanic glasses and minerals generated in the process of devitrification in situ. Its quality is comparable to non-metallic alumosilicate raw materials that are commercially used in building and ceramic industry. Two possibilities of fly ash utilization as the most bulk waste produced by anthropogenic activity were examined. The way of fly ashes utilization in the modeling of mixtures for the high refractory mullite corundum materials synthesis was examined. In this experiment 95.5% conversion of the input components of fly ash and Al additive in the ratio 1:1 on the mullite and corundum was obtained.

Keywords

  • black coal fly ash
  • mullitization
  • technolithes.
Open Access

Controllable preparation of highly active horseradish peroxidase-gold nanoparticle bionanoconjugate

Published Online: 12 Jan 2013
Page range: 57 - 60

Abstract

Abstract

A novel method of immobilizing horse radish peroxidase enzyme (HRP) onto the surface of gold nanoparticles (GNPs) was developed. As a result, a high-activity bionanoconjugates was obtained through utilizing the biotin-streptavidin (SA) system. The HRP-SA-GNP bionanoconjugate with high activity was conveniently prepared through the biotin- avidin system. Compared with the HRP-GNP bioconjugate prepared through the traditional electrostatic absorption method, the enzyme activity per GNPs of this new bionanoconjugate was enhanced by 10 times. Moreover, the enzyme activity of this bionanoconjugate was controllable. The above method of bionanoconjugation preparation has promising applications in the fields including preparing highly active bio-nanoprobe and immobilized enzyme.

Keywords

  • horseradish peroxidase
  • gold nanoparticles
  • bionanoconjugate.
Open Access

The effect of important parameters on the natural gas vehicles driving range

Published Online: 12 Jan 2013
Page range: 61 - 68

Abstract

Abstract

One of the most important issues regarding Natural Gas Vehicles (NGVs) is the Driving Range, which is defined as capability of a NGV to travel a certain distance after each refueling. The Driving Range is a serious obstacle in the development and growth of NGVs. Thus the necessity of studying the effects of various parameters on the Driving Range could be realized. It is found that the on-board storage capacity and the natural gas heating value have the greatest effect on the Driving Range. The charged mass of NGV cylinders is varied due to the natural gas composition and the final in-cylinder values (temperature and pressure). Underfilling of NGV cylinders, during charging operations, is a result of the elevated temperature which occurs in the NGV storage cylinder, due to compression and other processes could be overcome by applying extensive over-pressurization of the cylinder during the fuelling operation. Here, the effects of the most important parameters on the Driving Range have been investigated. The parameters are natural gas composition, engine efficiency and final NGV on-board in-cylinder temperature and pressure. It is found that, the composition has big effects on the Driving Range. The results also show that as final in-cylinder pressure decreases (or temperature increases), the Driving Range will be increased.

Keywords

  • Natural gas vehicle
  • Driving Range
  • Compressed Natural Gas (CNG)
  • Thermodynamic properties
  • CNG fuelling station.
Open Access

Simultaneous synthesis-immobilization of nano ZnO on perlite for photocatalytic degradation of an azo dye in semi batch packed bed photoreactor

Published Online: 12 Jan 2013
Page range: 69 - 76

Abstract

Abstract

A novel, simple and simultaneous synthesis-immobilization of nano ZnO on perlite (nZnO-P) as a photocatalyst for photocatalytic degradation of Acid orange 7 (AO7) in aqueous solution was investigated. The effect of operational parameters such as initial dye concentration, initial pH, flow rate, photocatalyst granule size, temperature and the kinetic of the removal of AO7 in terms of the Langmuir-Hinshelwood model in a designed semi batch packed bed photoreactor connected to an on-line sampling UV-Vis spectrophotometer was studied. The results showed that AO7 removal efficiency increased with nZnO-P using the designed setup and the proposed photocatalyst was more efficient than TiO2 as a standard catalyst. Our results confirmed the pseudo-first-order kinetics model. The values of the adsorption equilibrium constant, KAO7, the kinetic rate constant of surface reaction, kc, and the activation energy (Ea) were found to be 0.57 (mg.l−1)−1, 0.41 mg.l−1.min−1 and 11.44 kJ/mol, respectively.

Keywords

  • Natural gas vehicle
  • Driving Range
  • Compressed Natural Gas (CNG)
  • Thermodynamic properties
  • CNG fuelling station.
Open Access

Dehydrogenation of propane with CO2 – a new green process for propene and synthesis gas production

Published Online: 12 Jan 2013
Page range: 77 - 82

Abstract

Abstract

Dehydrogenation of propane in the presence of CO2 was considered as an alternative to commercial dehydrogenation pathway of obtaining propene and the new sources of synthesis gas. Based on thermodynamic calculations and a catalytic tests it was shown that by controlling CO2 concentration in the feed the molar ratio of H2/CO (synthesis gas) in the products mixture can be regulated. Several different pathways of DHP-CO2 process integration with commercialized chemical processes utilized synthesis gas were proposed

Keywords

  • Dehydrogenation with CO2
  • propene
  • synthesis gas
  • integrated processes.
Open Access

Drying of binary thin film polymeric coatings: an experimental study

Published Online: 12 Jan 2013
Page range: 83 - 87

Abstract

Abstract

Four binary polymer -solvent systems, poly(styrene)-tetrahydrofuran, poly(styrene) - p-xylene, poly(methyl methacrylate) - ethylbenzene and poly(methyl methacrylate) - tetrahydrofuran, systems have been studied. It has been observed that thicker coatings will retain a higher amount of the residual solvent as compared to thinner coatings. In the case of poly(styrene)-tetrahydrofuran coating residual solvent remaining within the coatings were 9.09% and 4.74% for the coatings of the thicknesses of 967 micron and 559 micron, respectively. Similar trends were also observed in the case of poly(methyl methacrylate)-ethylbenzene, poly(methyl methacrylate)-tetrahydrofuran, and poly(styrene)-p-xylene systems.

Keywords

  • Binary Coatings
  • Thin Films
  • Drying
  • Diffusion.
Open Access

Comparative studies on the removal of copper (II) by Ulva fasciata activated carbon and commercially activated carbon

Published Online: 12 Jan 2013
Page range: 88 - 94

Abstract

Abstract

In this work, the efficiency of Ulva fasciata sp. activated carbons (CCUC, SCUC and SSUC) and commercially activated carbon (CAC) were studied for the removal of Cu (II) ions from synthetic wastewater. Batch adsorption experiments were carried out as a function of pH, contact time, initial copper concentration and adsorbent dose. The percentage adsorption of copper by CCUC, SSUC, SCUC and CAC are 88.47%, 97.53%, 95.78% and 77.42% respectively. Adsorption data were fitted with the Langmuir, Freundlich and Temkin models. Two kinetic models pseudo first order and the pseudo second order were selected to interpret the adsorption data.

Keywords

  • Ulva fasciata sp.
  • synthetic wastewater
  • Activated carbons
  • Adsorption
  • Langmuir
Open Access

Adsorption of humic acid on mesoporous carbons prepared from poly- (ethylene terephthalate) templated with magnesium compounds

Published Online: 12 Jan 2013
Page range: 95 - 99

Abstract

Abstract

Porous carbons obtained from poly(ethylene terephtalate) contained in a mixture with either MgCO3 or Mg(OH)2 were examined as adsorbents for removal of humic acid from water. Adsorption of the model contaminants is discussed in relation to the textural parameters of the obtained carbon materials. Pore structure parameters of the carbonaceous materials were strongly influenced by preparation conditions including temperature and relative amounts of the inorganics used during preparations as template. Porous carbons prepared revealed a potential to purify water from the model contaminant of high molecular weight. The results presented confirmed a key role of mesoporosity in the adsorption of humic acid. Fluorescence spectroscopy was confirmed to be an useful method to evaluate concentration of humic acid in water.

Keywords:

  • porous carbon
  • adsorption
  • humic acid
  • fluorescence spectroscopy.
Open Access

Enhancement of the pool boiling heat transfer coefficient using the gas injection into the water

Published Online: 12 Jan 2013
Page range: 100 - 109

Abstract

Abstract

In this paper, a new method for enhancing the pool boiling heat transfer coefficient of pure liquid, based on the gas injection through the liquids has been introduced. Hence, the effect of gas dissolved in a stagnant liquid on pool boiling heat transfer coefficient, nucleation site density, and bubble departure diameter has experimentally been investigated for different mole fractions of SO2 and various heat fluxes up to 114 kW/ m2. The presence of SO2 in captured vapor inside the bubbles, particularly around the heat transfer surface increases the pool boiling heat transfer coefficient. The available predicted correlations are unable to obtain the reasonable values for pool boiling heat transfer coefficient in this particular case. Therefore, to predict the pool boiling heat transfer coefficient accurately, a new modified correlation based on Stephan-Körner relation has been proposed. Also, during the experiments, it is found that nucleation site density is a strictly exponential function of heat flux. Accordingly, a new correlation has been obtained to predict the nucleation site density. The major application of the nucleation site density is in the estimating of mean bubble diameters as well as local agitation due to the rate of bubble frequency.

Keywords

  • Heat transfer
  • Pool boiling
  • Gas-liquid solution
  • Nucleation site density
  • SO2
  • water.
18 Articles
Open Access

The utilization possibility of waste lignite as a raw material in the process of obtaining humic acids preparations

Published Online: 12 Jan 2013
Page range: 1 - 6

Abstract

Abstract

In the light of environmental law utilization lignite waste in non-energy sectors of the economy is a rational way to manage them. Lignite due to the lower degree of coalification and calorific value as well as a high content of humic substances becomes a valuable component of fertilizer. The paper presents the possibility of using lignite waste as a raw material in the process of obtaining humic acids with 0.1 M NaOH. The idea of the process combines production, environmental and economic purposes. After the extraction process of humic acids and considering the possibility of using waste formed during the process, were carried out a number of studies to assist in choosing the best solution to its management.

Keywords

  • brown coals
  • humic acids
  • extraction
  • alkaline w
Open Access

Application of the side stream from the cyklopol process in paint stripping formulations

Published Online: 12 Jan 2013
Page range: 7 - 10

Abstract

Abstract

The utilization of two side streams from the Cyklopol process was studied. The first one is the monohydric alcohols fraction and the second one is the fraction of mono-carboxylic acids. We propose to utilize these fractions and their esters as a component of gel formulation painting remover. Our composites have a gel formulation suitable for easy application on a vertical surface. D-DBS (1,3:2,4-Di-O-benzylidene-Dsorbitol) or MHPC (methylhydroxypropylcellulose) were used as gelling agents for organic liquids. The D-DBS compound is characterized by transparency and reduced yellowing of composition. The properties of the obtained preparations were compared to the properties of commercially available gel formulations SCANSOL and STRIPER. Our initial investigations indicate that side streams from the Cyklopol process are good and cheap resources of raw materials for the preparation of paint stripping formulations.

Keywords

  • Cyklopol
  • side stream
  • paint removing
  • gel formulation.
Open Access

Recycling of styrofoam waste: synthesis, characterization and application of novel phenyl thiosemicarbazone surface

Published Online: 12 Jan 2013
Page range: 11 - 18

Abstract

Abstract

An attempt has been made to recycle Styrofoam waste to a novel functional polymer, Phenyl thiosemicarbazone surface (PTS). Polystyrene (PS) obtained from Styrofoam waste was acetylated and then condensed to PTS by reacting it with 4-Phenyl-3-thiosemicarbazide ligand and characterized by FT-IR spectroscopy and elemental analysis. Synthesized PTS was applied successfully for the treatment of lead contaminated water by batch extraction method. Sorption variables were optimized (pH 8, adsorbent dose 53mg, initial Pb(II) ion concentration 10mgl-1 and agitation time 90min) by factorial design approach. Lead uptake by PTS was found much sensitive to the pH of Pb(II) ion solution. The maximum removal (99.61%) of Pb(II) ions was achieved at optimum conditions. The Langmuir and D-R isotherm study suggested the monolayer, favorable (RL=0.0001-0.01) and chemisorption (E=20.41±0.12kJmol-1) nature of the adsorption process. The sorption capacity of PTS was found to be 45.25±0.69mgg-1. The FT-IR spectroscopy study showed the involvement of nitrogen and sulphur of thiosemicarbazone moiety of PTS for the uptake of Pb(II) ions by five membered chelate formation.

Keywords

  • Recycling
  • Styrofoam
  • Functional polymer
  • Pb(II) ion removal
  • Phenyl thiosemicarbazone surface
  • Factorial Design Approach.
Open Access

Bromine catalyst for the methane to methyl bisulfate reaction

Published Online: 12 Jan 2013
Page range: 19 - 21

Abstract

Abstract

A catalytic system KBr - oleum is effective at catalyzing the selective oxidation of methane to methanol via. methyl bisulfate. The influences of methane pressure, sulfur trioxide and temperature on turnover frequency were investigated.

Keywords

  • methane
  • methyl bisulfate
  • methanol
  • KBr
Open Access

Development of approach to modelling and optimization of non-stationary catalytic processes in oil refining and petrochemistry

Published Online: 12 Jan 2013
Page range: 22 - 29

Abstract

Abstract

An approach to modelling of non-stationary catalytic processes of oil refining and petrochemistry is proposed. The computer modelling systems under development take into account the physical and chemical reaction laws, raw materials composition, and catalyst nature. This allows using the software for the optimization of process conditions and equipment design. The models created can be applied for solving complex problems of chemical reactors design; calculation of different variants of industrial plants reconstruction; refining and petrochemicals catalysts selection and testing; catalyst service life prolongation; determination of optimum water supply into the alkanes dehydrogenation reactor; optimization of products separation in the benzene alkylation process.

Keywords

  • oil refining
  • mathematical model
  • non-stationary
  • technological mode
  • forecasting.
Open Access

Surface active agent production from olive oil in high salt conditions and its process optimization

Published Online: 12 Jan 2013
Page range: 30 - 34

Abstract

Abstract

Microbial surfactants or biosurfactants are surface active amphiphilic macromolecules that are produced by a number of microorganisms (bacteria, yeast and fungi). These compounds have extensive application in various industries especially in food, pharmaceutical and oil industry. The aim of this paper is to optimize the culture conditions for the biosurfactant production from olive oil by a novel halophilic isolate microorganism. The Taguchi experimental design methodology based analysis of olive oil as carbon source, yeast extract as nitrogen source and KH2PO4 as phosphorus source revealed that the olive oil and yeast extract significantly affect biosurfactant production in high salt conditions. Maximum biosurfactant (E24= 40%) produced in the presence of 4% (v/v) olive oil, 0.2% (w/v) yeast extract, and 0.002% (w/v) KH2PO4 . In conclusion, halophilic archaeon Haloarcula sp. IRU1 could be a potential microorganism for the production of biosurfactant from olive oil as carbon source in high salt conditions. The optimal parameters obtained during the optimization process were: olive oil 4%, yeast extract 0.4% and KH2PO4 0.004%.

Keywords

  • Surface active agent
  • Olive oil
  • optimization
  • Taguchi experimental design methodology.
Open Access

Meso-tetraphenylporphyriniron(iii) chloride catalyzed oxidation of aniline and its substituents by magnesium monoperoxyphthalate in aqueous acetic acid medium

Published Online: 12 Jan 2013
Page range: 35 - 41

Abstract

Abstract

The catalytic properties of the first generation catalyst meso-tetraphenylporphyriniron(III) chloride and magnesium monoperoxyphthalate (MMPP) as oxidant have been studied in the oxidation of aniline and its substituents in acetic acid medium. The thermodynamic parameters for the oxidation have been determined and discussed. It confirms the Exner relationship (only at the low range of temperatures) and also some of the activation parameters to the isokinetic relationships. The magnesium monoperoxyphthalate oxidation with 18 ortho- meta- and para-substituted anilines fulfills with isokinetic relationship but not to any of the linear free energy relationships. The reaction mechanism and the rate law were proposed.

Keywords

  • Aniline oxidation
  • kinetics
  • mechanism
  • magnesium monoperoxyphthalate
  • mesotetraphenylporphyriniron( III) chloride
  • catalyst.
Open Access

Liquid-solid interaction during formation of nanocomposite systems

Published Online: 12 Jan 2013
Page range: 42 - 45

Abstract

Abstract

Structural changes in mixtures of liquid Bi with small Cu and Ni particles were studied at temperatures of 615 and 1145K. Microstructures of the composites were observed (SEM) and analyzed after treatment at different temperatures and various durations of stirring. The structure of the mixtures of Bi with Cu(Ni) particles was investigated by means of X-ray diffraction, both in the solid and liquid state.

Keywords

  • composite materials
  • liquid metals and alloys
  • metallic powders
  • microstructure
  • short-range order.
Open Access

Artificial neural network to predict the natural convection from vertical and inclined arrays of horizontal cylinders

Published Online: 12 Jan 2013
Page range: 46 - 52

Abstract

Abstract

The main focus of the present study is to utilize the artificial neural network (ANN) in predicting the natural convection from horizontal isothermal cylinders arranged in vertical and inclined arrays. The effects of the vertical separation spacing to the cylinder diameter ratio (Py/d), horizontal separation spacing to the cylinder diameter ratio (Px/d) and Rayleigh number (Ra) variation on the average heat transfer from the arrays are considered via this prediction. The training data for optimizing the ANN structure is based on available experimental data. The Levenberg-Marquardt back propagation algorithm is used for ANN training. The proposed ANN is developed using MATLAB functions. For the best ANN structure obtained in this investigation, the mean relative errors of 0.027% and 0.482% were reached for the training and test data, respectively. The results show that the predicted values are very close to the experimental ones.

Keywords

  • Natural Convection
  • Inclined Array
  • Vertical Array
  • Modeling
  • Artificial Neural Network.
Open Access

Fly ash as the component of composites materials

Published Online: 12 Jan 2013
Page range: 53 - 56

Abstract

Abstract

The fly ash from powerplant can be compared, due to its genesis, chemical and mineralogical composition with the natural volcanic glasses and minerals generated in the process of devitrification in situ. Its quality is comparable to non-metallic alumosilicate raw materials that are commercially used in building and ceramic industry. Two possibilities of fly ash utilization as the most bulk waste produced by anthropogenic activity were examined. The way of fly ashes utilization in the modeling of mixtures for the high refractory mullite corundum materials synthesis was examined. In this experiment 95.5% conversion of the input components of fly ash and Al additive in the ratio 1:1 on the mullite and corundum was obtained.

Keywords

  • black coal fly ash
  • mullitization
  • technolithes.
Open Access

Controllable preparation of highly active horseradish peroxidase-gold nanoparticle bionanoconjugate

Published Online: 12 Jan 2013
Page range: 57 - 60

Abstract

Abstract

A novel method of immobilizing horse radish peroxidase enzyme (HRP) onto the surface of gold nanoparticles (GNPs) was developed. As a result, a high-activity bionanoconjugates was obtained through utilizing the biotin-streptavidin (SA) system. The HRP-SA-GNP bionanoconjugate with high activity was conveniently prepared through the biotin- avidin system. Compared with the HRP-GNP bioconjugate prepared through the traditional electrostatic absorption method, the enzyme activity per GNPs of this new bionanoconjugate was enhanced by 10 times. Moreover, the enzyme activity of this bionanoconjugate was controllable. The above method of bionanoconjugation preparation has promising applications in the fields including preparing highly active bio-nanoprobe and immobilized enzyme.

Keywords

  • horseradish peroxidase
  • gold nanoparticles
  • bionanoconjugate.
Open Access

The effect of important parameters on the natural gas vehicles driving range

Published Online: 12 Jan 2013
Page range: 61 - 68

Abstract

Abstract

One of the most important issues regarding Natural Gas Vehicles (NGVs) is the Driving Range, which is defined as capability of a NGV to travel a certain distance after each refueling. The Driving Range is a serious obstacle in the development and growth of NGVs. Thus the necessity of studying the effects of various parameters on the Driving Range could be realized. It is found that the on-board storage capacity and the natural gas heating value have the greatest effect on the Driving Range. The charged mass of NGV cylinders is varied due to the natural gas composition and the final in-cylinder values (temperature and pressure). Underfilling of NGV cylinders, during charging operations, is a result of the elevated temperature which occurs in the NGV storage cylinder, due to compression and other processes could be overcome by applying extensive over-pressurization of the cylinder during the fuelling operation. Here, the effects of the most important parameters on the Driving Range have been investigated. The parameters are natural gas composition, engine efficiency and final NGV on-board in-cylinder temperature and pressure. It is found that, the composition has big effects on the Driving Range. The results also show that as final in-cylinder pressure decreases (or temperature increases), the Driving Range will be increased.

Keywords

  • Natural gas vehicle
  • Driving Range
  • Compressed Natural Gas (CNG)
  • Thermodynamic properties
  • CNG fuelling station.
Open Access

Simultaneous synthesis-immobilization of nano ZnO on perlite for photocatalytic degradation of an azo dye in semi batch packed bed photoreactor

Published Online: 12 Jan 2013
Page range: 69 - 76

Abstract

Abstract

A novel, simple and simultaneous synthesis-immobilization of nano ZnO on perlite (nZnO-P) as a photocatalyst for photocatalytic degradation of Acid orange 7 (AO7) in aqueous solution was investigated. The effect of operational parameters such as initial dye concentration, initial pH, flow rate, photocatalyst granule size, temperature and the kinetic of the removal of AO7 in terms of the Langmuir-Hinshelwood model in a designed semi batch packed bed photoreactor connected to an on-line sampling UV-Vis spectrophotometer was studied. The results showed that AO7 removal efficiency increased with nZnO-P using the designed setup and the proposed photocatalyst was more efficient than TiO2 as a standard catalyst. Our results confirmed the pseudo-first-order kinetics model. The values of the adsorption equilibrium constant, KAO7, the kinetic rate constant of surface reaction, kc, and the activation energy (Ea) were found to be 0.57 (mg.l−1)−1, 0.41 mg.l−1.min−1 and 11.44 kJ/mol, respectively.

Keywords

  • Natural gas vehicle
  • Driving Range
  • Compressed Natural Gas (CNG)
  • Thermodynamic properties
  • CNG fuelling station.
Open Access

Dehydrogenation of propane with CO2 – a new green process for propene and synthesis gas production

Published Online: 12 Jan 2013
Page range: 77 - 82

Abstract

Abstract

Dehydrogenation of propane in the presence of CO2 was considered as an alternative to commercial dehydrogenation pathway of obtaining propene and the new sources of synthesis gas. Based on thermodynamic calculations and a catalytic tests it was shown that by controlling CO2 concentration in the feed the molar ratio of H2/CO (synthesis gas) in the products mixture can be regulated. Several different pathways of DHP-CO2 process integration with commercialized chemical processes utilized synthesis gas were proposed

Keywords

  • Dehydrogenation with CO2
  • propene
  • synthesis gas
  • integrated processes.
Open Access

Drying of binary thin film polymeric coatings: an experimental study

Published Online: 12 Jan 2013
Page range: 83 - 87

Abstract

Abstract

Four binary polymer -solvent systems, poly(styrene)-tetrahydrofuran, poly(styrene) - p-xylene, poly(methyl methacrylate) - ethylbenzene and poly(methyl methacrylate) - tetrahydrofuran, systems have been studied. It has been observed that thicker coatings will retain a higher amount of the residual solvent as compared to thinner coatings. In the case of poly(styrene)-tetrahydrofuran coating residual solvent remaining within the coatings were 9.09% and 4.74% for the coatings of the thicknesses of 967 micron and 559 micron, respectively. Similar trends were also observed in the case of poly(methyl methacrylate)-ethylbenzene, poly(methyl methacrylate)-tetrahydrofuran, and poly(styrene)-p-xylene systems.

Keywords

  • Binary Coatings
  • Thin Films
  • Drying
  • Diffusion.
Open Access

Comparative studies on the removal of copper (II) by Ulva fasciata activated carbon and commercially activated carbon

Published Online: 12 Jan 2013
Page range: 88 - 94

Abstract

Abstract

In this work, the efficiency of Ulva fasciata sp. activated carbons (CCUC, SCUC and SSUC) and commercially activated carbon (CAC) were studied for the removal of Cu (II) ions from synthetic wastewater. Batch adsorption experiments were carried out as a function of pH, contact time, initial copper concentration and adsorbent dose. The percentage adsorption of copper by CCUC, SSUC, SCUC and CAC are 88.47%, 97.53%, 95.78% and 77.42% respectively. Adsorption data were fitted with the Langmuir, Freundlich and Temkin models. Two kinetic models pseudo first order and the pseudo second order were selected to interpret the adsorption data.

Keywords

  • Ulva fasciata sp.
  • synthetic wastewater
  • Activated carbons
  • Adsorption
  • Langmuir
Open Access

Adsorption of humic acid on mesoporous carbons prepared from poly- (ethylene terephthalate) templated with magnesium compounds

Published Online: 12 Jan 2013
Page range: 95 - 99

Abstract

Abstract

Porous carbons obtained from poly(ethylene terephtalate) contained in a mixture with either MgCO3 or Mg(OH)2 were examined as adsorbents for removal of humic acid from water. Adsorption of the model contaminants is discussed in relation to the textural parameters of the obtained carbon materials. Pore structure parameters of the carbonaceous materials were strongly influenced by preparation conditions including temperature and relative amounts of the inorganics used during preparations as template. Porous carbons prepared revealed a potential to purify water from the model contaminant of high molecular weight. The results presented confirmed a key role of mesoporosity in the adsorption of humic acid. Fluorescence spectroscopy was confirmed to be an useful method to evaluate concentration of humic acid in water.

Keywords:

  • porous carbon
  • adsorption
  • humic acid
  • fluorescence spectroscopy.
Open Access

Enhancement of the pool boiling heat transfer coefficient using the gas injection into the water

Published Online: 12 Jan 2013
Page range: 100 - 109

Abstract

Abstract

In this paper, a new method for enhancing the pool boiling heat transfer coefficient of pure liquid, based on the gas injection through the liquids has been introduced. Hence, the effect of gas dissolved in a stagnant liquid on pool boiling heat transfer coefficient, nucleation site density, and bubble departure diameter has experimentally been investigated for different mole fractions of SO2 and various heat fluxes up to 114 kW/ m2. The presence of SO2 in captured vapor inside the bubbles, particularly around the heat transfer surface increases the pool boiling heat transfer coefficient. The available predicted correlations are unable to obtain the reasonable values for pool boiling heat transfer coefficient in this particular case. Therefore, to predict the pool boiling heat transfer coefficient accurately, a new modified correlation based on Stephan-Körner relation has been proposed. Also, during the experiments, it is found that nucleation site density is a strictly exponential function of heat flux. Accordingly, a new correlation has been obtained to predict the nucleation site density. The major application of the nucleation site density is in the estimating of mean bubble diameters as well as local agitation due to the rate of bubble frequency.

Keywords

  • Heat transfer
  • Pool boiling
  • Gas-liquid solution
  • Nucleation site density
  • SO2
  • water.