1,721,155 research outputs found
sj-docx-1-pie-10.1177_09544089211058093 - Supplemental material for MHD radiative flow of Williamson nanofluid along stretching sheet in a porous medium with convective boundary conditions
No full textSupplemental material, sj-docx-1-pie-10.1177_09544089211058093 for MHD radiative flow of Williamson nanofluid along stretching sheet in a porous medium with convective boundary conditions by Imran Ullah in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
Synthesis, characterisation and charge storage behaviour of some transition metal nitrides
No full textThe application of nanostructured materials with ordered morphologies and properties to electrochemical capacitors (ECs) is being studied in order to provide enhanced energy density without comprising their inherent high power density and excellent cyclability. In this study we have synthesised some metal nitrides through various routes using non-oxide precursor sources and studied their structure, composition and morphology. As synthesised materials were made in to electrodes and their capacitances were measured using cyclic voltammetry.Manganese nitrides were obtained in a solvothermal synthesis by reacting MnCl2 and LiNH2. Nanotubes at 350 °C or spherical shape particles were seen at higher temperatures. Capacitances were seen to drop with scan number when run for longer periods at higher scan rates. Molybdenum nitride samples were obtained by solution phase ammonolysis of MoCl5 or Mo(NMe2)4 to obtain the polymers. Annealing the choloroimide polymer yielded hexagonal MoN at 500 °C, rock salt Mo2N at 700 °C and above and a mix of both the phases at 600 °C. Imide derivatives yielded distorted cubic up to 800 °C and a mix of hexagonal and rock salt at high temperature. Nanotubes were obtained from imide derivatives up to 900 °C, while spherical particles above this temperature and for chloroimide derivatives at any temperature. CVs obtained for chloroimide derivatives show to double layer supercapacitors dominating over redox reaction, while imide derivatives were found to be redox in nature. Chloroimide samples show high capacities up to 247 F g-1 at 2 mV s-1 and long cycling lifetime for both the derivatives through 1000 cycles.Vanadium nitride samples were obtained by solution phase ammonolysis of V(NMe2)4. Annealing the polymer at various temperatures under NH3 produced VN with standard rock salt structure at 500-1000 °C while distorted rock salt in the samples obtained at lower temperature. Particles were found to be spherical in shape. Highest capacitance of 128 F g-1 was seen for the sample obtained at 600 °C at lower 2 mV s-1. Capacitance was found to be stable through 1000 scans only when a short potential window was used. TiN samples were produced by obtaining a precursor from solution phase ammonolysis of Ti(NMe2)4 and annealing the precursor under ammonia or through sol-gel route using long chain amines as the templating agents. PXD patterns showed rock salt TiN with broad peaks at 500 °C or highly crystalline at 800 °C. TEM images suggested particles to be spherical in shape. A fairly high surface area of 319 m2 g-1 was observed for the sample obtained from annealing the HDA/PrNH2 polymer at 500 °C. Cyclic voltammograms showed poor charge storage and most of the samples tend to oxidise rapidly in aqueous KOH. VN/C samples were obtained carrying an overnight reaction of V(NMe2)4 with NH3 in a hydrothermal bomb at various temperature. PXD reviled rock salt VN, some distortion was in the structure was found in the sample obtained at lower temperature. TEM images show vanadium nitride nano particles with carbon nanotubes. Specific capacitances were observed to be decreased with scan number through 100 cycles in 1 M KOH
Synthesis of transition metal nitrides and silicon based ternary nitrides
No full textSolution phase ammonolysis and sol-gel techniques that produce polymeric metal-amide precursors are of growing interest in the synthesis of nitride materials, which result from the thermal decomposition of the polymer. They can be used to control composition and to produce a large number of useful morphologies such as nanoparticles, films, monoliths, aerogels, and materials with large surface area such as foams. The synthesis of nitride materials using ammonolysis of metal amides and chlorides has so far largely focused on producing powders for applications such as catalysis, or thin films by chemical vapour deposition and related techniques.In this thesis, formation of tantalum and molybdenum nitride nanoparticles and metal-silicon nitride based nanocomposites have been synthesised using non-oxide precursors by solution phase ammonolysis and sol-gel methods respectively. For tantalum nitride nanoparticles Ta(NMe2)5 in THF was ammonolysed with ammonia at - 78 °C and the polymeric precursor was pyrolysed at various temperatures under ammonia. Amorphous TaN was obtained at 700 °C and below, while Ta3N5 was obtained at 800 °C under ammonia and also by re-annealing the amorphous samples at 800 °C under nitrogen. Molybdenum nitride powders were obtained by solution phase ammonolysis of MoCl5 or Mo(NMe2)4 and further annealing the polymeric precursors on different temperatures. The chloride precursor resulted in hexagonal MoNx at 500 °C, or rock salt MoNx at 700-1000 °C and mixture of both at 600 °C. The amide precursor resulted phase pure hexagonal MoNx at 600 °C and rock salt mixed with hexagonal at 1000 °C. Samples produced at 600 °C consisted mainly of nanotubes. Some decomposition to molybdenum metal was found in MoN obtained at 1000 °C from either precursor source.Co-ammonolysis of Ta(NMe2)5 or Mo(NMe2)4 with Si(NHMe)4 was carried out using sol-gel technique. Polymeric metal-silicon amide precursors were annealed at 600 or 1000 °C. The Ta/Si precursor produced amorphous nanocomposites and no phase segregation was observed even after high temperature annealing. With molybdenum the products were nanocomposites of molybdenum nitride particles, including nanotubes, supported on a silicon nitride amorphous matrix
sj-docx-1-pie-10.1177_09544089221131147 - Supplemental material for Thermal scrutinization of magetohydrodynamics CuO engine oil nanofluid flow across a horizontal surface via Koo–Kleinstreuer–Li modeling: A thermal case study
No full textSupplemental material, sj-docx-1-pie-10.1177_09544089221131147 for Thermal scrutinization of magetohydrodynamics CuO engine oil nanofluid flow across a horizontal surface via Koo–Kleinstreuer–Li modeling: A thermal case study by Syed M Hussain, Faisal Shahzad, Wasim Jamshed, Mohammad Kalimuddin Ahmad, Zulfiqar Rehman and Imran Ullah in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
Supplementary_figure - CD105<sup>+</sup> Porcine Endometrial Stromal Mesenchymal Stem Cells Possess Differentiation Potential Toward Cardiomyocyte-Like Cells and Insulin-Producing β Cell-Like Cells In Vitro
No full textSupplementary_figure for CD105+ Porcine Endometrial Stromal Mesenchymal Stem Cells Possess Differentiation Potential Toward Cardiomyocyte-Like Cells and Insulin-Producing β Cell-Like Cells In Vitro by Raghavendra Baregundi Subbarao, Sharath Belame Shivakumar, Yong-Ho Choe, Young-Bum Son, Hyeon-Jeong Lee, Imran Ullah, Si-Jung Jang, Sun-A Ock, Sung-Lim Lee, and Gyu-Jin Rho in Reproductive Sciences</p
MHD free convection flow of Casson fluid over a permeable nonlinearly stretching sheet with chemical reaction
No full textThe problem of heat and mass transfer free convection flow of Casson fluid over a porous nonlinear
stretching sheet in the presence of chemical reaction is investigated. Moreover the effect of magnetic
field is also considered. The governing partial differential equations are transformed into ordinary
differential equations by making use of suitable transformations and then solved numerically via Kellerbox
method. The results for skin friction are compared with previous results of the existing literature.
The results are also reflected in good agreement. It is noted that concentration of Casson fluid reduces
rapidly by increasing Schmidt number and chemical parameter. Also, thermal Grashof number and
mass Grashof number enhance the momentum boundary layer thickness, whereas increment in
chemical reaction parameter reduces the heat transfer rate. Moreover, both the fluid velocity and wall
shear stress are observed to be decreased with increment in suction/blowing parameter
Heat generation and absorption in mhd flow of casson fluid past a stretching wedge with viscous dissipation and newtonian heating
No full textThe dissipative flow of Casson fluid in the presence of heat generation and absorption is investigated. The flow is induced due to stretching wedge. The similarity transformations were used to to transformed the governing equations into ordinary differential equations. The transformed equations are solved numerically via Keller-box method. Numerical results for skin friction coefficient are compared and found in excellent agreement with published results. The effects of pertinent parameters on velocity and temperature profiles as well as skin friction and heat transfer rate are graphically displayed and analyzed. It is noticed that fluid velocity drops with the increase of Casson fluid and magnetic parameters when the wedge is stretching faster than free stream. It is also noted that the heat transfer rate at wedge surface reduces with the increase of Eckert number, whereas the reverse trend is noted in the case of Casson and radiation parameters. Moreover, with increasing of heat generation or absorption parameter the fluid temperature rises
MHD heat transfer flow of Casson fluid past a stretching wedge subject to suction and injection
No full textThe steady two dimensional incompressible hydromagnetic boundary layer flow caused by stretching wedge immersed in Casson fluid with heat transfer and suction/injection is investigated numerically. The governing nonlinear partial differential equations are transformed into nonlinear ordinary differential equations using suitable transformations and then solved numerically via Keller-box method. Numerical results for local skin friction coefficient are compared with the existing literature and observed in closed agreement with those results. The effects of pertinent parameters on flow fields are displayed graphically and discussed. It is found that velocity decreases with increase of Casson parameter and wedge angle parameter when the wedge is stretching faster than free stream. It is also observed that rate of heat transfer at surface increases with the increase of Prandtl number and Casson fluid parameter. Moreover, with increase of suction parameter the fluid velocity decreases and rate of shear stress increases
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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