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Full-Text Articles in Physical Sciences and Mathematics

Numerical Solution Of Hybrid Nanofluid And Its Stability Over Permeable Wedge Sheet With Heat Transfer Analysis, Aisha M. Alqahtani, Zeeshan, Waris Khan, Florentin Smarandache, Nidhal Becheikh, Roobaea Alroobaea, Taseer Muhammad Jan 2024

Numerical Solution Of Hybrid Nanofluid And Its Stability Over Permeable Wedge Sheet With Heat Transfer Analysis, Aisha M. Alqahtani, Zeeshan, Waris Khan, Florentin Smarandache, Nidhal Becheikh, Roobaea Alroobaea, Taseer Muhammad

Branch Mathematics and Statistics Faculty and Staff Publications

The inclusion of nanoparticles has the potential to improve the thermal efficiency of the base fluid. The field of nanofluid (NF) dynamics has attracted important attention due to its extensive range of practical uses like fuel cells, solar energy, medication administration, heat transfer, microfabrication, coolant applications, and other related domains. The aim of this study is to scrutinize the impact of Lorentz force, thermal energy, joule heating, heat source and injection parameters, and Brownian and thermoporetic diffusions on the hybrid nanofluid over the moving wedge. The stability inquiry is reported for the existing work in order to confirm the stable …


Low-Load Metal-Assisted Catalytic Etching Produces Scalable Porosity In Si Powders, Konstantin Tamarov, Riku Kiviluoto, Josph D. Swanson, Bret A. Unger, Alexis T. Ernst, Mark Aindow, Joakim Riikonen, Vesa-Pekka Lehto, Kurt W. Kolasinski Oct 2020

Low-Load Metal-Assisted Catalytic Etching Produces Scalable Porosity In Si Powders, Konstantin Tamarov, Riku Kiviluoto, Josph D. Swanson, Bret A. Unger, Alexis T. Ernst, Mark Aindow, Joakim Riikonen, Vesa-Pekka Lehto, Kurt W. Kolasinski

Chemistry Faculty Publications

The recently discovered low-load metal-assisted catalytic etching (LL-MACE) creates nanostructured Si with controllable and variable characteristics that distinguish this technique from the conventional high-load variant. LL-MACE employs 150 times less metal catalyst and produces porous Si instead of Si nanowires. In this work, we demonstrate that some of the features of LL-MACE cannot be explained by the present understanding of MACE. With mechanistic insight derived from extensive experimentation, it is demonstrated that (1) the method allows the use of not only Ag, Pd, Pt, and Au as metal catalysts but also Cu and (2) judicious combinations of process parameters such …


R-Silsesquioxane-Based Network Polymers By Fluoride Catalyzed Synthesis: An Investigation Of Cross-Linker Structure And Its Influence On Porosity, Nai-Hsuan Hu, Joseph C. Furgal Apr 2020

R-Silsesquioxane-Based Network Polymers By Fluoride Catalyzed Synthesis: An Investigation Of Cross-Linker Structure And Its Influence On Porosity, Nai-Hsuan Hu, Joseph C. Furgal

Chemistry Faculty Publications

Silsesquioxane-based networks are an important class of materials that have many applications where high thermal/oxidative stability and porosity are needed simultaneously. However, there is a great desire to be able to design these materials for specialized applications in environmental remediation and medicine. To do so requires a simple synthesis method to make materials with expanded functionalities. In this article, we explore the synthesis of R-silsesquioxane-based porous networks by fluoride catalysis containing methyl, phenyl and vinyl corners (R-Si(OEt)) combined with four different bis-triethoxysilyl cross-linkers (ethyl, ethylene, acetylene and hexyl). Synthesized materials were then analyzed for their porosity, surface area, thermal stability …


Building Mof Nanocomposites With Oxidized Graphitic Carbon Nitride Nanospheres: The Effect Of Framework Geometry On The Structural Heterogeneity, Dimitrios A. Giannakoudakis, Teresa J. Bandosz Dec 2019

Building Mof Nanocomposites With Oxidized Graphitic Carbon Nitride Nanospheres: The Effect Of Framework Geometry On The Structural Heterogeneity, Dimitrios A. Giannakoudakis, Teresa J. Bandosz

Publications and Research

Composite of two MOFs, copper-based Cu-BTC (HKUST-1) and zirconium-based Zr-BDC (UiO-66), with oxidized graphitic carbon nitride nanospheres were synthesized. For comparison, pure MOFs were also obtained. The surface features were analyzed using x-ray diffraction (XRD), sorption of nitrogen, thermal analysis, and scanning electron microscopy (SEM). The incorporation of oxidized g-C3N4 to the Cu-BTC framework caused the formation of a heterogeneous material of a hierarchical pores structure, but a decreased surface area when compared to that of the parent MOF. In the case of UiO-66, functionalized nanospheres were acting as seeds around which the crystals grew. Even though the MOF phases …


Tio2/S-Doped Carbons Hybrids: Analysis Of Their Interfacial And Surface Features, Teresa Bandosz, Alfonso Policicchio, Marc Florent, Po S. Poon, Juan Matos Oct 2019

Tio2/S-Doped Carbons Hybrids: Analysis Of Their Interfacial And Surface Features, Teresa Bandosz, Alfonso Policicchio, Marc Florent, Po S. Poon, Juan Matos

Publications and Research

Hybrids containing approximately equal amounts of P25 TiO2 and S-doped porous carbons were prepared using a water-based slurry mixing method. The materials were extensively characterized by adsorption of nitrogen, potentiometric titration, thermal analysis in air and in helium, XRD, XPS and SEM. The collected results showed the significant blockage of carbon micropores by TiO2 particles deposited on their outer surface. The formation of a new interface, especially for the S-rich samples, might also contribute to the porosity alteration. Analysis of surface chemistry suggested the presence of Ti-S bonds with an involvement of sulfur from thiophenic species in the carbon phase. …


Efficient Air Desulfurization Catalysts Derived From Pig Manure Liquefaction Char, Rajiv Wallace, Sundaramurthy Suresh, Elham H. Fini, Teresa Bandosz Nov 2017

Efficient Air Desulfurization Catalysts Derived From Pig Manure Liquefaction Char, Rajiv Wallace, Sundaramurthy Suresh, Elham H. Fini, Teresa Bandosz

Publications and Research

Biochar from the liquefaction of pig manure was used as a precursor of H2S desulfurization adsorbents. In its inorganic matter, it contains marked quantities of calcium, magnesium and iron, which are known as hydrogen sulfide oxidation catalysts. The char was used either as-received or mixed with 10% nanographite. The latter was added to increase both the content of the carbon phase and conductivity. ZnCl2 in two different ratios of char to an activation agent (1:1 and 1:2) was used to create the porosity in the carbon phase. The content of the later was between 18–45%. The activated samples adsorbed 144 …


Effects Of Activated Carbon Surface Chemistry Modification On The Adsorption Of Mercury From Aqueous Solution, Emily K. Faulconer Jan 2012

Effects Of Activated Carbon Surface Chemistry Modification On The Adsorption Of Mercury From Aqueous Solution, Emily K. Faulconer

Publications

Mercury (Hg), a naturally occurring element, is toxic and can lead to negative health impacts for humans and ecosystems. Activated carbon adsorption is effective in treating Hg-laden aqueous effluent for safe discharge. Two modifications of commercially available activated carbon were investigated: iron impregnation to allow for magnetic sorbent recapture and wet chemical oxidation to enhance aqueous Hg capture. The modified carbons were characterized by nitrogen adsorption-desorption, XRD, pHpzc, vibrating sample magnetometry, elemental analysis, and total acidity titration. The 3:1 C:Fe magnetic powdered activated carbon (MPAC) retained a high surface area of 790 m2 /g and was 95% magnetically recoverable, with …


Simulations Of Nanopore Formation And Phosphatidylserine Externalization In Lipid Membranes Subjected To A High-Intensity, Ultrashort Electric Pulse, Q. Hu, R. P. Joshi, K. H. Schoenbach Jan 2005

Simulations Of Nanopore Formation And Phosphatidylserine Externalization In Lipid Membranes Subjected To A High-Intensity, Ultrashort Electric Pulse, Q. Hu, R. P. Joshi, K. H. Schoenbach

Bioelectrics Publications

A combined MD simulator and time dependent Laplace solver are used to analyze the electrically driven phosphatidylserine externalization process in cells. Time dependent details of nanopore formation at cell membranes in response to a high-intensity (100kV∕cm), ultrashort (10ns) electric pulse are also probed. Our results show that nanosized pores could typically be formed within about 5ns. These predictions are in very good agreement with recent experimental data. It is also demonstrated that defect formation and PS externalization in membranes should begin on the anode side. Finally, the simulations confirm that PS externalization is a nanopore facilitated event, rather than the …