The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Waqar Ahmad - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen Production through Steam Reforming of Diesel over Highly Efficient Promoted Ni/γ-Al2O3 Catalysts Containing Lanthanide Series (La, Ce, Eu, Pr, and Gd) Promoters
Energy & Fuels, 2018Co-Authors: Muhammad Naeem Younis, Zuhair Omar Malaibari, Waqar Ahmad, Shakeel AhmedAbstract:The wet incipient impregnation technique was used for the synthesis of nonpromoted and Lanthanide Series-promoted (La, Ce, Eu, Pr, and Gd) Ni/γ-Al2O3 catalysts. The physicochemical properties of the catalysts were determined using X-ray diffraction, Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), scanning electron microscopy, energy dispersive X-ray, and temperature-programmed reduction (TPR) characterization techniques. Activity and the resistance to coke formation of nonpromoted and Lanthanide Series-promoted 12%Ni/γ-Al2O3 catalysts were investigated for diesel steam reforming in a fixed-bed reaction system. BET analysis showed no remarkable difference in the surface area of 12%Ni/γ-Al2O3 and 5%Pr–12%Ni/γ-Al2O3 (Pr–Ni) catalyst as compared to other promoted 12%Ni/γ-Al2O3 catalysts. Pr–Ni catalyst also has the higher BET surface area among other synthesized Lanthanide-promoted 12%Ni/γ-Al2O3 catalysts. TEM analysis indicated uniform metal dispersion of promoted catalysts. Moreover, T...
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synthesis of Lanthanide Series la ce pr eu gd promoted ni γ al2o3 catalysts for methanation of co2 at low temperature under atmospheric pressure
Catalysis Communications, 2017Co-Authors: Muhammad Naeem Younis, Waqar Ahmad, Reyad Shawabkeh, Shakeel AhmedAbstract:Abstract A Series of Ni/γ-Al 2 O 3 and 5%X-12%Ni/γ-Al 2 O 3 (X = La, Ce, Pr, Eu & Gd) catalysts was synthesized by using aqueous incipient impregnation method for methanation of carbon dioxide. 5%Pr-12%Ni/γ-Al 2 O 3 showed the highest CO 2 conversion of 98.2% with 100% CH 4 selectivity at 300 °C for investigated reaction conditions. The catalyst activity was also tested for 48 h which showed the stability of synthesized catalyst for CO 2 conversion and CH 4 selectivity. The TEM, BET and XRD analysis demonstrated the high metal dispersion, no remarkable effect on textural properties of 5%Pr-12%Ni/γ-Al 2 O 3 as compared to 12%Ni/γ-Al 2 O 3 and phases of alumina, nickel and Lanthanide Series promoters for γ-Al 2 O 3 support, 12%Ni/γ-Al 2 O 3 and 5%X-12%Ni/γ-Al 2 O 3 catalysts.
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Synthesis of Lanthanide Series (La, Ce, Pr, Eu & Gd) promoted Ni/γ-Al2O3 catalysts for methanation of CO2 at low temperature under atmospheric pressure
Catalysis Communications, 2017Co-Authors: Waqar Ahmad, Muhammad Naeem Younis, Reyad Shawabkeh, Shakeel AhmedAbstract:Abstract A Series of Ni/γ-Al 2 O 3 and 5%X-12%Ni/γ-Al 2 O 3 (X = La, Ce, Pr, Eu & Gd) catalysts was synthesized by using aqueous incipient impregnation method for methanation of carbon dioxide. 5%Pr-12%Ni/γ-Al 2 O 3 showed the highest CO 2 conversion of 98.2% with 100% CH 4 selectivity at 300 °C for investigated reaction conditions. The catalyst activity was also tested for 48 h which showed the stability of synthesized catalyst for CO 2 conversion and CH 4 selectivity. The TEM, BET and XRD analysis demonstrated the high metal dispersion, no remarkable effect on textural properties of 5%Pr-12%Ni/γ-Al 2 O 3 as compared to 12%Ni/γ-Al 2 O 3 and phases of alumina, nickel and Lanthanide Series promoters for γ-Al 2 O 3 support, 12%Ni/γ-Al 2 O 3 and 5%X-12%Ni/γ-Al 2 O 3 catalysts.
Shakeel Ahmed - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen Production through Steam Reforming of Diesel over Highly Efficient Promoted Ni/γ-Al2O3 Catalysts Containing Lanthanide Series (La, Ce, Eu, Pr, and Gd) Promoters
Energy & Fuels, 2018Co-Authors: Muhammad Naeem Younis, Zuhair Omar Malaibari, Waqar Ahmad, Shakeel AhmedAbstract:The wet incipient impregnation technique was used for the synthesis of nonpromoted and Lanthanide Series-promoted (La, Ce, Eu, Pr, and Gd) Ni/γ-Al2O3 catalysts. The physicochemical properties of the catalysts were determined using X-ray diffraction, Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), scanning electron microscopy, energy dispersive X-ray, and temperature-programmed reduction (TPR) characterization techniques. Activity and the resistance to coke formation of nonpromoted and Lanthanide Series-promoted 12%Ni/γ-Al2O3 catalysts were investigated for diesel steam reforming in a fixed-bed reaction system. BET analysis showed no remarkable difference in the surface area of 12%Ni/γ-Al2O3 and 5%Pr–12%Ni/γ-Al2O3 (Pr–Ni) catalyst as compared to other promoted 12%Ni/γ-Al2O3 catalysts. Pr–Ni catalyst also has the higher BET surface area among other synthesized Lanthanide-promoted 12%Ni/γ-Al2O3 catalysts. TEM analysis indicated uniform metal dispersion of promoted catalysts. Moreover, T...
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synthesis of Lanthanide Series la ce pr eu gd promoted ni γ al2o3 catalysts for methanation of co2 at low temperature under atmospheric pressure
Catalysis Communications, 2017Co-Authors: Muhammad Naeem Younis, Waqar Ahmad, Reyad Shawabkeh, Shakeel AhmedAbstract:Abstract A Series of Ni/γ-Al 2 O 3 and 5%X-12%Ni/γ-Al 2 O 3 (X = La, Ce, Pr, Eu & Gd) catalysts was synthesized by using aqueous incipient impregnation method for methanation of carbon dioxide. 5%Pr-12%Ni/γ-Al 2 O 3 showed the highest CO 2 conversion of 98.2% with 100% CH 4 selectivity at 300 °C for investigated reaction conditions. The catalyst activity was also tested for 48 h which showed the stability of synthesized catalyst for CO 2 conversion and CH 4 selectivity. The TEM, BET and XRD analysis demonstrated the high metal dispersion, no remarkable effect on textural properties of 5%Pr-12%Ni/γ-Al 2 O 3 as compared to 12%Ni/γ-Al 2 O 3 and phases of alumina, nickel and Lanthanide Series promoters for γ-Al 2 O 3 support, 12%Ni/γ-Al 2 O 3 and 5%X-12%Ni/γ-Al 2 O 3 catalysts.
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Synthesis of Lanthanide Series (La, Ce, Pr, Eu & Gd) promoted Ni/γ-Al2O3 catalysts for methanation of CO2 at low temperature under atmospheric pressure
Catalysis Communications, 2017Co-Authors: Waqar Ahmad, Muhammad Naeem Younis, Reyad Shawabkeh, Shakeel AhmedAbstract:Abstract A Series of Ni/γ-Al 2 O 3 and 5%X-12%Ni/γ-Al 2 O 3 (X = La, Ce, Pr, Eu & Gd) catalysts was synthesized by using aqueous incipient impregnation method for methanation of carbon dioxide. 5%Pr-12%Ni/γ-Al 2 O 3 showed the highest CO 2 conversion of 98.2% with 100% CH 4 selectivity at 300 °C for investigated reaction conditions. The catalyst activity was also tested for 48 h which showed the stability of synthesized catalyst for CO 2 conversion and CH 4 selectivity. The TEM, BET and XRD analysis demonstrated the high metal dispersion, no remarkable effect on textural properties of 5%Pr-12%Ni/γ-Al 2 O 3 as compared to 12%Ni/γ-Al 2 O 3 and phases of alumina, nickel and Lanthanide Series promoters for γ-Al 2 O 3 support, 12%Ni/γ-Al 2 O 3 and 5%X-12%Ni/γ-Al 2 O 3 catalysts.
Anchaleeporn W Lothongkum - One of the best experts on this subject based on the ideXlab platform.
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synergistic separation of yttrium ions in Lanthanide Series from rare earths mixture via hollow fiber supported liquid membrane
Journal of Industrial and Engineering Chemistry, 2009Co-Authors: Prakorn Ramakul, Ura Pancharoen, Tossaporn Supajaroon, Tatchanok Prapasawat, Anchaleeporn W LothongkumAbstract:Abstract Separation of yttrium ions from the mixture of rare earths in Lanthanide Series has been examined by a microporous hydrophobic hollow fiber supported liquid membrane. Cyanex 272 and TBP in kerosene are used separately as an extractant. Nitric acid solution is used as a stripping solution. Increasing the concentration of Cyanex 272 increases the percentages of extraction and stripping of yttrium from rare earths but slightly percentages are obtained by TBP. Interestingly, when TBP is added with Cyanex 272, the percentages of extraction and stripping increases. This is due to the synergistic effect of the extractants. Moreover, yttrium can be selectively extracted and stripped more than other Lanthanide ions because the equilibrium constant decreases with an increase in atomic number or decreases with the ionic radius of the Lanthanides. In other words, yttrium is separated selectively due to the smallest ionic radius while other Lanthanides are separated with a decrease in ionic radius or an increase in atomic number.
Norman P. Barnes - One of the best experts on this subject based on the ideXlab platform.
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Compositionally tuned lasers: Practical lasers at designer wavelengths
Optical Materials, 2005Co-Authors: Norman P. BarnesAbstract:A general need exists for practical solid state lasers at particular wavelengths. For NASA, these particular wavelengths are needed for remote sensing of atmospheric constituents such as water vapor and green house gasses. Transition metal solid state lasers can be widely tuned, however, they usually possess a relatively short upper laser level lifetime or a relatively small emission cross section. Either of these parameters can limit the practicality of transition metal lasers. On the other hand, Lanthanide Series solid state lasers have attractive upper laser level lifetimes and emission cross sections, however they have narrow tuning ranges. This problem is solved by utilizing the concept of compositional tuning of Lanthanide Series lasers. Compositional tuning effects, including the tuning range, are predicted using quantum mechanical calculations. They are also experimentally verified by means of spectroscopic measurements. Practical examples for two Lanthanide Series lasers that were compositionally tuned to a preselected water vapor absorption feature are presented. Both flash lamp pumped and diode pumped laser results are presented.
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Lasers for remote sensing: common solutions for uncommon wavelengths
Lidar Remote Sensing for Industry and Environmental Monitoring V, 2005Co-Authors: Norman P. Barnes, Brian M. Walsh, Donald J. Reichle, Theresa J. AxensonAbstract:Remote sensing requires efficient lasers that are tunable over a short wavelength range around a particular atmospheric absorption feature of interest. High efficiency usually implies Lanthanide Series lasers. Although Lanthanide Series lasers have sufficient tuning capability, they must operate at preselected atmospheric absorption features. Often, there is no commonly available laser that operates at the requisite wavelength. This type of problem can be addressed using compositional tuning to create a laser at a preselected wavelength where none existed before. Quantum mechanics is an invaluable tool to predict the effects of compositional tuning. Quantum mechanical predictions are confirmed with spectroscopic measurements. Laser performance data for a laser that operates at 0.9441 μm, a preselected water vapor absorption feature, are featured.
Smruti Dash - One of the best experts on this subject based on the ideXlab platform.
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Study of variation in thermophysical properties of RE_6UO_12(s) along the Lanthanide Series
Journal of Radioanalytical and Nuclear Chemistry, 2017Co-Authors: Manjulata Sahu, K. Krishnan, Buddhadev Kanrar, M. K. Saxena, Smruti DashAbstract:The variation in thermophysical properties along the Lanthanide Series for RE_6UO_12(s) was investigated. Structural characterization of Er_6UO_12(s) was carried out by Rietveld refinement method. The trend in heat capacity along the rare earth Series for RE_6UO_12(s) and RE_2O_3(s) as function of ionic radius of RE^3+ was found to be similar. Hence, the sole cause of excess heat capacity in rare earth uranates was concluded to be the rare earth ion. Linear relation was found between the thermal expansion coefficient of RE_6UO_12(s) (RE = La, Gd, Lu) and the ionic radii of rare earth ion.
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Study of variation in thermophysical properties of RE 6 UO 12 (s) along the Lanthanide Series
Journal of Radioanalytical and Nuclear Chemistry, 2017Co-Authors: Manjulata Sahu, K. Krishnan, Buddhadev Kanrar, M. K. Saxena, Smruti DashAbstract:The variation in thermophysical properties along the Lanthanide Series for RE6UO12(s) was investigated. Structural characterization of Er6UO12(s) was carried out by Rietveld refinement method. The trend in heat capacity along the rare earth Series for RE6UO12(s) and RE2O3(s) as function of ionic radius of RE3+ was found to be similar. Hence, the sole cause of excess heat capacity in rare earth uranates was concluded to be the rare earth ion. Linear relation was found between the thermal expansion coefficient of RE6UO12(s) (RE = La, Gd, Lu) and the ionic radii of rare earth ion.
