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Papers by Mostafa Haghroosta

International Journal of Refractory Metals & Hard Materials, 2010

In this study the W/Cu and W/ZrC composites have been fabricated by hot-press and then their mech... more In this study the W/Cu and W/ZrC composites have been fabricated by hot-press and then their mechanical properties were compared in addition to their ablation resistance. To produce W-20vol.%Cu composite at first stage the elemental W and Cu powders were ball milled for 3 h in rotation speed of 200 rpm, in which 2% nickel was added in order to reduce the density. The mixed powders were hot-pressed for 1 h at 1400°C and compact pressure of 30 MPa. Additionally W/40vol.%ZrC composite has been fabricated by hotpressing of mixed W and ZrC powders in 30 MPa and 2200°C for 1 h. Since these materials are used at elevated temperature applications, where ablation is the main source of material failure, after producing the composites their ablation resistance was evaluated in a real condition. The results show that not only W-ZrC composite is better than W-Cu composite in mechanical properties, but also in ablation resistance.

International Journal of Refractory Metals & Hard Materials, 2011

In this study the W-ZrC composites fabricated by in situ reaction sintering of two precursors wer... more In this study the W-ZrC composites fabricated by in situ reaction sintering of two precursors were compared, 1-The conventional WC and ZrO 2 which are ball milled with established molar ratio of 3-1 for 12 hours, gelcasted to form a green body and then undergo a pressure less sintering cycle, 2-A new and innovative way in which for the first time ZrSiO 4 was used instead of ZrO 2 , and by testing different molar ratio between WC and ZrSiO 4 it was understood that the optimum ratio is 3-1 once again. Furthermore the starting ZrO 2 and ZrSiO 4 powder were selected in nano size and it was understood that by using nano powders the amount of unreacted and unwanted phase reduce, the reaction progress and the mechanical proprieties improve. Although the reaction sintered WC/ZrO 2 possess better properties, regarding the cost considerations, reaction sintering of WC/ZrSiO 4 is a much cheaper process.

International Journal of Environmental Analytical Chemistry, 2012

Trace amounts of Fe3+, Pb2+, Cu2+, Ni2+, Co2+ and Zn2+ ions were efficiently enriched following c... more Trace amounts of Fe3+, Pb2+, Cu2+, Ni2+, Co2+ and Zn2+ ions were efficiently enriched following complexation with silica-gel chemically functionalized with 2-((3-silylpropylimino)methyl)-5-bromophenol. The enriched metal ions efficiently eluted with 6 mL of 4.0 mol L−1 nitric acid and their metal contents were determined by flame atomic absorption spectrometry (FAAS). The influences of the analytical parameters and experimental variables on the recoveries of the metal ions under study were investigated and optimized. The method has high sorption preconcentration efficiency even in the presence of various interfering ions. At optimum values of all variables the method is applicable for analysis of real samples with recoveries in the range of 95 to 105% with RSD lower than 4.2% and detection limits between 1.4 and 2.8 µg L−1.

Toxicological & Environmental Chemistry, 2012

In this work, an efficient adsorption system for the removal of bromothymol blue (BTB) from an aq... more In this work, an efficient adsorption system for the removal of bromothymol blue (BTB) from an aqueous solution using oxidized multiwalled carbon nanotubes (MWCNTs-COOH) has been described. The influence of effective variables such as solution pH, contact time, initial BTB concentration, amount of MWCNTs-COOH, and temperature on the adsorption efficiency in batch system was examined while BTB content was determined via UV-Vis spectrophotometer. Among different kinetic models (pseudo-first-order, pseudo-second-order, intra-particle diffusion, and Elovich model), experimental data of the removal process well fitted with the pseudo-second-order kinetic model with a high correlation coefficient. Evaluating the fitness of experimental equilibrium data by various conventional isotherm models including the Langmuir, Freundlich, and Tempkin models (based on considering R 2 value as criterion) show the applicability of the Langmuir model for the interpretation of experimental data with a maximum adsorption capacity of 55 mg g−1 of adsorbent. Thermodynamic parameters (Gibb's free energy, entropy and enthalpy) of adsorption show that the adsorption process has endothermic nature.

Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy

In the present research, cadmium hydroxide nanowire loaded on activated carbon (Cd(OH)(2)-NW-AC) ... more In the present research, cadmium hydroxide nanowire loaded on activated carbon (Cd(OH)(2)-NW-AC) was synthesized and characterized. This new adsorbent was applied for the removal of Bromocresol Green (BCG) molecules from aqueous solutions. The influence of effective variables such as solution pH, contact time, initial BCG concentration, amount of Cd(OH)(2)-NW-AC and temperature on the adsorption efficiency of BCG in batch system was examined. During all experiments BCG contents were determined by UV-Vis spectrophotometer. Fitting the experimental data to different kinetic models including pseudo-first-order, pseudo-second-order, Elovich and intra-particle diffusion kinetic models show the suitability of the pseudo-second-order kinetic model to interpret in the experimental data. Equilibrium isotherm studies were examined by application of different conventional models such as Langmuir, Freundlich and Tempkin models to explain the experimental data. Based on considering R(2) value as criterion the adsorption data well fitted to Langmuir model with maximum adsorption capacity of 108.7 mg g(-1). Thermodynamic parameters (Gibb's free energy, entropy and enthalpy) of adsorption were calculated according to general procedure to take some information about the on-going adsorption process. The high negative value of Gibb's free energy and positive value of enthalpy show the feasibility and endothermic nature of adsorption process.

Toxicological & Environmental Chemistry, 2012

In this work, a new procedure for the enrichment of the trace amount of Cu2+, Ni2+, Co2+, Pb2+, F... more In this work, a new procedure for the enrichment of the trace amount of Cu2+, Ni2+, Co2+, Pb2+, Fe2+, and Zn2+ ions based on the utilization of multiwalled carbon nanotubes (MWCNT) modified with 2-(2-hydroxy-5-nitrophenyl)-4,5-diphenyl imidazole as chelating agent prior to their determination by flame atomic absorption spectrometry has been described. The influence of effective parameters including pH, amount of ligand and MWCNT, composition of eluent, and coexisting ions on recoveries of understudy metal ions was examined. At the optimum pH of 5.0, all metal ions were quantitatively sorbed onto the proposed solid phase and completely desorbed with 8 mL of 5.0 mol L−1 HNO3. The detection limit of Cu2+, Co2+, Ni2+, Pb2+, Fe2+, and Zn2+ ions was 1.7, 2.4, 2.3, 2.9, 2.8, and 1.4 µg L−1, while the preconcentration factor was 63 for Cu2+ and 94 for the other metal ions and relative standard deviations between 1.8 less than 3.0%. The proposed procedure was applied for the analysis of various samples.

International Journal of Refractory Metals & Hard Materials, 2010

In this study the W/Cu and W/ZrC composites have been fabricated by hot-press and then their mech... more In this study the W/Cu and W/ZrC composites have been fabricated by hot-press and then their mechanical properties were compared in addition to their ablation resistance. To produce W-20vol.%Cu composite at first stage the elemental W and Cu powders were ball milled for 3 h in rotation speed of 200 rpm, in which 2% nickel was added in order to reduce the density. The mixed powders were hot-pressed for 1 h at 1400°C and compact pressure of 30 MPa. Additionally W/40vol.%ZrC composite has been fabricated by hotpressing of mixed W and ZrC powders in 30 MPa and 2200°C for 1 h. Since these materials are used at elevated temperature applications, where ablation is the main source of material failure, after producing the composites their ablation resistance was evaluated in a real condition. The results show that not only W-ZrC composite is better than W-Cu composite in mechanical properties, but also in ablation resistance.

International Journal of Refractory Metals & Hard Materials, 2011

In this study the W-ZrC composites fabricated by in situ reaction sintering of two precursors wer... more In this study the W-ZrC composites fabricated by in situ reaction sintering of two precursors were compared, 1-The conventional WC and ZrO 2 which are ball milled with established molar ratio of 3-1 for 12 hours, gelcasted to form a green body and then undergo a pressure less sintering cycle, 2-A new and innovative way in which for the first time ZrSiO 4 was used instead of ZrO 2 , and by testing different molar ratio between WC and ZrSiO 4 it was understood that the optimum ratio is 3-1 once again. Furthermore the starting ZrO 2 and ZrSiO 4 powder were selected in nano size and it was understood that by using nano powders the amount of unreacted and unwanted phase reduce, the reaction progress and the mechanical proprieties improve. Although the reaction sintered WC/ZrO 2 possess better properties, regarding the cost considerations, reaction sintering of WC/ZrSiO 4 is a much cheaper process.

International Journal of Environmental Analytical Chemistry, 2012

Trace amounts of Fe3+, Pb2+, Cu2+, Ni2+, Co2+ and Zn2+ ions were efficiently enriched following c... more Trace amounts of Fe3+, Pb2+, Cu2+, Ni2+, Co2+ and Zn2+ ions were efficiently enriched following complexation with silica-gel chemically functionalized with 2-((3-silylpropylimino)methyl)-5-bromophenol. The enriched metal ions efficiently eluted with 6 mL of 4.0 mol L−1 nitric acid and their metal contents were determined by flame atomic absorption spectrometry (FAAS). The influences of the analytical parameters and experimental variables on the recoveries of the metal ions under study were investigated and optimized. The method has high sorption preconcentration efficiency even in the presence of various interfering ions. At optimum values of all variables the method is applicable for analysis of real samples with recoveries in the range of 95 to 105% with RSD lower than 4.2% and detection limits between 1.4 and 2.8 µg L−1.

Toxicological & Environmental Chemistry, 2012

In this work, an efficient adsorption system for the removal of bromothymol blue (BTB) from an aq... more In this work, an efficient adsorption system for the removal of bromothymol blue (BTB) from an aqueous solution using oxidized multiwalled carbon nanotubes (MWCNTs-COOH) has been described. The influence of effective variables such as solution pH, contact time, initial BTB concentration, amount of MWCNTs-COOH, and temperature on the adsorption efficiency in batch system was examined while BTB content was determined via UV-Vis spectrophotometer. Among different kinetic models (pseudo-first-order, pseudo-second-order, intra-particle diffusion, and Elovich model), experimental data of the removal process well fitted with the pseudo-second-order kinetic model with a high correlation coefficient. Evaluating the fitness of experimental equilibrium data by various conventional isotherm models including the Langmuir, Freundlich, and Tempkin models (based on considering R 2 value as criterion) show the applicability of the Langmuir model for the interpretation of experimental data with a maximum adsorption capacity of 55 mg g−1 of adsorbent. Thermodynamic parameters (Gibb's free energy, entropy and enthalpy) of adsorption show that the adsorption process has endothermic nature.

Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy

In the present research, cadmium hydroxide nanowire loaded on activated carbon (Cd(OH)(2)-NW-AC) ... more In the present research, cadmium hydroxide nanowire loaded on activated carbon (Cd(OH)(2)-NW-AC) was synthesized and characterized. This new adsorbent was applied for the removal of Bromocresol Green (BCG) molecules from aqueous solutions. The influence of effective variables such as solution pH, contact time, initial BCG concentration, amount of Cd(OH)(2)-NW-AC and temperature on the adsorption efficiency of BCG in batch system was examined. During all experiments BCG contents were determined by UV-Vis spectrophotometer. Fitting the experimental data to different kinetic models including pseudo-first-order, pseudo-second-order, Elovich and intra-particle diffusion kinetic models show the suitability of the pseudo-second-order kinetic model to interpret in the experimental data. Equilibrium isotherm studies were examined by application of different conventional models such as Langmuir, Freundlich and Tempkin models to explain the experimental data. Based on considering R(2) value as criterion the adsorption data well fitted to Langmuir model with maximum adsorption capacity of 108.7 mg g(-1). Thermodynamic parameters (Gibb's free energy, entropy and enthalpy) of adsorption were calculated according to general procedure to take some information about the on-going adsorption process. The high negative value of Gibb's free energy and positive value of enthalpy show the feasibility and endothermic nature of adsorption process.

Toxicological & Environmental Chemistry, 2012

In this work, a new procedure for the enrichment of the trace amount of Cu2+, Ni2+, Co2+, Pb2+, F... more In this work, a new procedure for the enrichment of the trace amount of Cu2+, Ni2+, Co2+, Pb2+, Fe2+, and Zn2+ ions based on the utilization of multiwalled carbon nanotubes (MWCNT) modified with 2-(2-hydroxy-5-nitrophenyl)-4,5-diphenyl imidazole as chelating agent prior to their determination by flame atomic absorption spectrometry has been described. The influence of effective parameters including pH, amount of ligand and MWCNT, composition of eluent, and coexisting ions on recoveries of understudy metal ions was examined. At the optimum pH of 5.0, all metal ions were quantitatively sorbed onto the proposed solid phase and completely desorbed with 8 mL of 5.0 mol L−1 HNO3. The detection limit of Cu2+, Co2+, Ni2+, Pb2+, Fe2+, and Zn2+ ions was 1.7, 2.4, 2.3, 2.9, 2.8, and 1.4 µg L−1, while the preconcentration factor was 63 for Cu2+ and 94 for the other metal ions and relative standard deviations between 1.8 less than 3.0%. The proposed procedure was applied for the analysis of various samples.