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Volume 24 (2022): Issue 3 (September 2022)

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Volume 24 (2022): Issue 1 (March 2022)

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Volume 23 (2021): Issue 2 (June 2021)

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Volume 20 (2018): Issue 4 (December 2018)

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Volume 18 (2016): Issue 4 (December 2016)

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Volume 17 (2015): Issue 4 (December 2015)

Volume 17 (2015): Issue 3 (September 2015)

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Volume 16 (2014): Issue 4 (December 2014)

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Volume 16 (2014): Issue 2 (June 2014)

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Volume 15 (2013): Issue 4 (December 2013)

Volume 15 (2013): Issue 3 (September 2013)

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

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Volume 13 (2011): Issue 4 (December 2011)

Volume 13 (2011): Issue 3 (September 2011)

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Volume 12 (2010): Issue 3 (September 2010)

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Volume 9 (2007): Issue 1 (March 2007)

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

Search

Volume 24 (2022): Issue 1 (March 2022)

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

Search

7 Articles
Open Access

An analytical model for wicking in porous media based on statistical geometry theory

Published Online: 13 Apr 2022
Page range: 1 - 6

Abstract

Abstract

In this work, an analytical model describing liquid wicking phenomenon in porous media was constructed, based on the statistical geometry theory and the fractal theory. In the model, a new structure-property relationship, depicted by specific surface, porosity, tortuosity, pore fractal dimension, maximum pore size of the porous media, was introduced into the energy conservation equation. According to the theoretical model, the accumulated imbibition weight in porous media was achieved, and the predictions were verified by available experimental data published in different literatures. Besides, structure parameters influencing the imbibition process upon approaching equilibrium height were discussed. The model and results in this work are useful for the application of porous media in scientific research and industry.

Keywords

  • Wicking
  • Statistical geometry
  • Fractal
  • Porous media
Open Access

Electrochemical synthesis of Zinc oxide/polymer/phosphotungstic acid composites for a UV detector

Published Online: 13 Apr 2022
Page range: 7 - 14

Abstract

Abstract

ZnO is an ideal material for UV detection. However, due to the surface effect of ZnO, the photosensitivity of the ZnO based UV detector needs to be improved. In this study, we deposited a hydroxyl group functionalized (3,4-propylenethiophene) polymer (PProDOT-OH) film onto a hydrothermally grown ZnO nanoarray by electro-chemical deposition method to prevent the corrosion of ZnO by phosphotungsten acid (PWA), and then PWA was drip-coated on the composite film to prepare the ZnO/PProDOT-OH/PWA composite based UV detector. The structure and morphology of the composite were characterized by SEM, UV–vis, FT-IR, XRD, Raman, EDS, XPS analysis, illustrating the phosphotungstic acid was uniformly coated on ZnO/PProDOT-OH surface and confirming the composite was successfully synthesized. The UV detection performance was studied through preparing a UV detector with the composite material and results indicate that the introduction of PWA could enhance the responsivity of the ZnO/PProDOT-OH composite-based UV detector.

Keywords

  • UV detector
  • ZnO
  • phosphotungsten acid
  • composite
Open Access

Study on NH3-SCR of Cerium-based Substances in Rare Earth Concentrates from Bayan Obo

Published Online: 13 Apr 2022
Page range: 15 - 22

Abstract

Abstract

In this paper, CePO4 and CeCO3F were prepared by hydrothermal synthesis based on the ratio of bastnaesite to monazite in the process mineralogy of Baiyun Ebo rare earth concentrate. A comparison of the two treatments, ball milling and ball milling sulphation, revealed that the denitrification efficiency of the catalysts treated with ball milling sulphation increased by 20 percentage points, compared to those treated without sulphation, with denitrification efficiencies of up to 80%. The surface properties, redox properties and catalytic mechanism of the samples before and after the sulphation treatment were analyzed, by using XRD, NH3-TPD, H2-TPR, XPS and in situ IR characterization. The results showed that the CeF3 diffraction peaks in the XRD patterns disappeared in the sulphated samples, NH3-TPD showed that the adsorption capacity of NH3 on the surface of the samples was enhanced, and the introduction of sulphuric acid provided a large number of acidic sites on the catalyst surface, among which the Lewis acidic sites might be more favorable for the promotion of SCR reaction. The acidification of sulphuric acid greatly increases the redox capacity of the catalyst, and the interconversion between Cen+ was enhanced. XPS showed a significant increase in the amount of adsorbed oxygen on the surface of the sample. The presence of -NO2, an important intermediate in the L-H mechanism, was also detected by IR analysis. reactant species during the L-H mechanism reaction were monodentate nitrate, bridged nitrate and NH4+ species produced by NH3 adsorption on the Brønsted acidic site of the catalyst surface.

Keywords

  • Rare earth concentrate
  • Sulfation
  • Denitrification
  • Catalytic synergy
Open Access

Facile synthesis and anticancer activity of novel dihydropyrimidinone derivatives

Published Online: 13 Apr 2022
Page range: 23 - 28

Abstract

Abstract

The enaminone, (2E)-3-(dimethylamino)-1-(3,4,5-trimethoxyphenyl) prop-2-en-1-one was prepared by refluxing 3,4,5-trimethoxy acetophenone with dimethylformamide dimethylacetal (DMF–DMA) without solvent for 12 h. The dihydropyrimidinone derivatives (1–9) were prepared by reacting enaminone, substituted benzaldehydes and urea in glacial acetic acid. The compounds (1–9) were synthesized in significant yield using one step multicomponent reaction. Structures of all the novel synthesized compounds were characterized and confirmed by various spectroscopic methods. The compounds were evaluated for their anti-cancer activity against HepG2 cancer cell line. Compound 9 displayed significant anti-cancer activity. During the apoptotic assay, it showed a significant increase in necrosis from 1.97% to 12.18% as compared to the control. Mechanism of anti-proliferation was performed by cell cycle distribution assay, which showed a decrease in G2+M from 12.90 to 8.13 as compared to control.

Keywords

  • Dihydropyrimidinone
  • enaminone
  • 3,4,5-trimethoxybenzoyl moiety
Open Access

Molecular docking, theoretical calculations, synthesis of Ru(III), Pd(II) and VO(II) complexes and activity determination as antibacterial and antioxidant

Published Online: 13 Apr 2022
Page range: 29 - 38

Abstract

Abstract

Molecular modeling calculations were used to validate 3D structures of new complexes of Ru(III), Pd(II) and VO(II) ions chelated with (E)-2-(phenylamino)-N-(pyridine-2-yl)methylene)acetohydrazide ligand. Furthermore, the calculations were used to estimate selected electronic chemical descriptors which are responsible for the biological activity. The first insight of the compound activity as antibacterial was evaluated by molecular docking analysis. The titled models showed stable binding towards lanosterol 14 alpha-demethylase (CYP51) enzyme of E. coli, indicating their inhibition effect toward bacterial growth. Structural study of the ligand and Ru(III), Pd(II) and VO(II) chelates was done using elemental analysis, FT-IR, 1H-NMR techniques. Furthermore, complexes were physically investigated based on magnetic moment, molar conductance, electronic spectroscopic and thermal analysis techniques. The antibacterial study of the synthesized compounds screened against both Gram-positive and Gram-negative bacteria revealed that these compounds display remarkable antibacterial activity and can be used as therapeutic drugs for pathogenic bacterial diseases. All complexes and ligand showed good scavenging activities which indicate a promising result for their applications as antioxidants.

Keywords

  • Hydrazide moiety
  • antioxidant activity
  • antibacterial activity
  • Molecular modeling
  • Docking
Open Access

Synthesis, molecular modelling and antibacterial activity of 4-aryl-thiosemicarbazides

Published Online: 13 Apr 2022
Page range: 39 - 46

Abstract

Abstract

N-Substituted phenyl/cyclohexyl-2-(pyridine-4-carbonyl) hydrazine-1-carbothioamides (2a–r) were synthesized, characterized by spectral and analytical data. The compounds were evaluated for antibacterial activity by the disc diffusion method. Most of the compounds showed activity against Gram-positive bacteria. Compound 2h with 4-Sulfapyrimidine phenyl substitution was found to be the most promising candidate, active against Gram-positive and methicillin-resistant Staphylococcus aureus (MRSA) strains with minimum inhibitory concentration (MIC) of (2–7 μg/mL). From the docking study, we predicted that compounds (2r, 2g, 2h, 2o, 2p and 2e) possess better antibacterial activity by having a good binding affinity with target protein and they could be used as potential drugs as antimicrobials. Amongst all the docked compounds, the compound 2h presented near binding affinity & interaction docking score with DNA gyrase enzymes with reference to ciprofloxacin.

Keywords

  • Aryl-thiosemicarbazides
  • antibacterial activity
  • molecular docking
  • DNAGyrase
Open Access

Preparation of hexamethylol melamine resin with low crystallization water and low viscosity for hexamethylol melamine/polyvinyl alcohol composite membrane

Published Online: 13 Apr 2022
Page range: 47 - 56

Abstract

Abstract

Hexamethylol melamine resins (HMM) with low crystallization water content and low viscosity were prepared by inhibiting the condensation polymerization of low hexamethylol melamine. The effects of catalyst, pH, formalde-hyde/melamine ratio, reaction temperature and time on the synthesis parameters of HMM were investigated. The results showed that the sample (HMM8) synthesized with Na2CO3-NaHCO3 as catalyst had the crystallization water content lower than 10%, being with a viscosity of about 0.26 Pa·s. The melting temperature of HMM8/polyvinyl alcohol (PVA) curing system was about 164.3 °C. It was found that the higher the amount of formaldehyde, the greater the hydroxyl methyl bounded to each triazine ring. Compared with the traditional melamine formaldehyde resin which had the crystallization water content of about 20–30%, the production of this resin was expected to reduce the energy consumption of industrial reaction, while the resin with 10% crystallization water content was more conducive to the development of alloying HMM/PVA composite membrane.

Keywords

  • low crystallization water content
  • low energy consumption
  • low viscosity
  • hexamethylol melamine/polyvinyl alcohol
  • composite membrane
7 Articles
Open Access

An analytical model for wicking in porous media based on statistical geometry theory

Published Online: 13 Apr 2022
Page range: 1 - 6

Abstract

Abstract

In this work, an analytical model describing liquid wicking phenomenon in porous media was constructed, based on the statistical geometry theory and the fractal theory. In the model, a new structure-property relationship, depicted by specific surface, porosity, tortuosity, pore fractal dimension, maximum pore size of the porous media, was introduced into the energy conservation equation. According to the theoretical model, the accumulated imbibition weight in porous media was achieved, and the predictions were verified by available experimental data published in different literatures. Besides, structure parameters influencing the imbibition process upon approaching equilibrium height were discussed. The model and results in this work are useful for the application of porous media in scientific research and industry.

Keywords

  • Wicking
  • Statistical geometry
  • Fractal
  • Porous media
Open Access

Electrochemical synthesis of Zinc oxide/polymer/phosphotungstic acid composites for a UV detector

Published Online: 13 Apr 2022
Page range: 7 - 14

Abstract

Abstract

ZnO is an ideal material for UV detection. However, due to the surface effect of ZnO, the photosensitivity of the ZnO based UV detector needs to be improved. In this study, we deposited a hydroxyl group functionalized (3,4-propylenethiophene) polymer (PProDOT-OH) film onto a hydrothermally grown ZnO nanoarray by electro-chemical deposition method to prevent the corrosion of ZnO by phosphotungsten acid (PWA), and then PWA was drip-coated on the composite film to prepare the ZnO/PProDOT-OH/PWA composite based UV detector. The structure and morphology of the composite were characterized by SEM, UV–vis, FT-IR, XRD, Raman, EDS, XPS analysis, illustrating the phosphotungstic acid was uniformly coated on ZnO/PProDOT-OH surface and confirming the composite was successfully synthesized. The UV detection performance was studied through preparing a UV detector with the composite material and results indicate that the introduction of PWA could enhance the responsivity of the ZnO/PProDOT-OH composite-based UV detector.

Keywords

  • UV detector
  • ZnO
  • phosphotungsten acid
  • composite
Open Access

Study on NH3-SCR of Cerium-based Substances in Rare Earth Concentrates from Bayan Obo

Published Online: 13 Apr 2022
Page range: 15 - 22

Abstract

Abstract

In this paper, CePO4 and CeCO3F were prepared by hydrothermal synthesis based on the ratio of bastnaesite to monazite in the process mineralogy of Baiyun Ebo rare earth concentrate. A comparison of the two treatments, ball milling and ball milling sulphation, revealed that the denitrification efficiency of the catalysts treated with ball milling sulphation increased by 20 percentage points, compared to those treated without sulphation, with denitrification efficiencies of up to 80%. The surface properties, redox properties and catalytic mechanism of the samples before and after the sulphation treatment were analyzed, by using XRD, NH3-TPD, H2-TPR, XPS and in situ IR characterization. The results showed that the CeF3 diffraction peaks in the XRD patterns disappeared in the sulphated samples, NH3-TPD showed that the adsorption capacity of NH3 on the surface of the samples was enhanced, and the introduction of sulphuric acid provided a large number of acidic sites on the catalyst surface, among which the Lewis acidic sites might be more favorable for the promotion of SCR reaction. The acidification of sulphuric acid greatly increases the redox capacity of the catalyst, and the interconversion between Cen+ was enhanced. XPS showed a significant increase in the amount of adsorbed oxygen on the surface of the sample. The presence of -NO2, an important intermediate in the L-H mechanism, was also detected by IR analysis. reactant species during the L-H mechanism reaction were monodentate nitrate, bridged nitrate and NH4+ species produced by NH3 adsorption on the Brønsted acidic site of the catalyst surface.

Keywords

  • Rare earth concentrate
  • Sulfation
  • Denitrification
  • Catalytic synergy
Open Access

Facile synthesis and anticancer activity of novel dihydropyrimidinone derivatives

Published Online: 13 Apr 2022
Page range: 23 - 28

Abstract

Abstract

The enaminone, (2E)-3-(dimethylamino)-1-(3,4,5-trimethoxyphenyl) prop-2-en-1-one was prepared by refluxing 3,4,5-trimethoxy acetophenone with dimethylformamide dimethylacetal (DMF–DMA) without solvent for 12 h. The dihydropyrimidinone derivatives (1–9) were prepared by reacting enaminone, substituted benzaldehydes and urea in glacial acetic acid. The compounds (1–9) were synthesized in significant yield using one step multicomponent reaction. Structures of all the novel synthesized compounds were characterized and confirmed by various spectroscopic methods. The compounds were evaluated for their anti-cancer activity against HepG2 cancer cell line. Compound 9 displayed significant anti-cancer activity. During the apoptotic assay, it showed a significant increase in necrosis from 1.97% to 12.18% as compared to the control. Mechanism of anti-proliferation was performed by cell cycle distribution assay, which showed a decrease in G2+M from 12.90 to 8.13 as compared to control.

Keywords

  • Dihydropyrimidinone
  • enaminone
  • 3,4,5-trimethoxybenzoyl moiety
Open Access

Molecular docking, theoretical calculations, synthesis of Ru(III), Pd(II) and VO(II) complexes and activity determination as antibacterial and antioxidant

Published Online: 13 Apr 2022
Page range: 29 - 38

Abstract

Abstract

Molecular modeling calculations were used to validate 3D structures of new complexes of Ru(III), Pd(II) and VO(II) ions chelated with (E)-2-(phenylamino)-N-(pyridine-2-yl)methylene)acetohydrazide ligand. Furthermore, the calculations were used to estimate selected electronic chemical descriptors which are responsible for the biological activity. The first insight of the compound activity as antibacterial was evaluated by molecular docking analysis. The titled models showed stable binding towards lanosterol 14 alpha-demethylase (CYP51) enzyme of E. coli, indicating their inhibition effect toward bacterial growth. Structural study of the ligand and Ru(III), Pd(II) and VO(II) chelates was done using elemental analysis, FT-IR, 1H-NMR techniques. Furthermore, complexes were physically investigated based on magnetic moment, molar conductance, electronic spectroscopic and thermal analysis techniques. The antibacterial study of the synthesized compounds screened against both Gram-positive and Gram-negative bacteria revealed that these compounds display remarkable antibacterial activity and can be used as therapeutic drugs for pathogenic bacterial diseases. All complexes and ligand showed good scavenging activities which indicate a promising result for their applications as antioxidants.

Keywords

  • Hydrazide moiety
  • antioxidant activity
  • antibacterial activity
  • Molecular modeling
  • Docking
Open Access

Synthesis, molecular modelling and antibacterial activity of 4-aryl-thiosemicarbazides

Published Online: 13 Apr 2022
Page range: 39 - 46

Abstract

Abstract

N-Substituted phenyl/cyclohexyl-2-(pyridine-4-carbonyl) hydrazine-1-carbothioamides (2a–r) were synthesized, characterized by spectral and analytical data. The compounds were evaluated for antibacterial activity by the disc diffusion method. Most of the compounds showed activity against Gram-positive bacteria. Compound 2h with 4-Sulfapyrimidine phenyl substitution was found to be the most promising candidate, active against Gram-positive and methicillin-resistant Staphylococcus aureus (MRSA) strains with minimum inhibitory concentration (MIC) of (2–7 μg/mL). From the docking study, we predicted that compounds (2r, 2g, 2h, 2o, 2p and 2e) possess better antibacterial activity by having a good binding affinity with target protein and they could be used as potential drugs as antimicrobials. Amongst all the docked compounds, the compound 2h presented near binding affinity & interaction docking score with DNA gyrase enzymes with reference to ciprofloxacin.

Keywords

  • Aryl-thiosemicarbazides
  • antibacterial activity
  • molecular docking
  • DNAGyrase
Open Access

Preparation of hexamethylol melamine resin with low crystallization water and low viscosity for hexamethylol melamine/polyvinyl alcohol composite membrane

Published Online: 13 Apr 2022
Page range: 47 - 56

Abstract

Abstract

Hexamethylol melamine resins (HMM) with low crystallization water content and low viscosity were prepared by inhibiting the condensation polymerization of low hexamethylol melamine. The effects of catalyst, pH, formalde-hyde/melamine ratio, reaction temperature and time on the synthesis parameters of HMM were investigated. The results showed that the sample (HMM8) synthesized with Na2CO3-NaHCO3 as catalyst had the crystallization water content lower than 10%, being with a viscosity of about 0.26 Pa·s. The melting temperature of HMM8/polyvinyl alcohol (PVA) curing system was about 164.3 °C. It was found that the higher the amount of formaldehyde, the greater the hydroxyl methyl bounded to each triazine ring. Compared with the traditional melamine formaldehyde resin which had the crystallization water content of about 20–30%, the production of this resin was expected to reduce the energy consumption of industrial reaction, while the resin with 10% crystallization water content was more conducive to the development of alloying HMM/PVA composite membrane.

Keywords

  • low crystallization water content
  • low energy consumption
  • low viscosity
  • hexamethylol melamine/polyvinyl alcohol
  • composite membrane

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