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Your search keyword '"Koshy, Pramod"' showing total 143 results
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143 results on '"Koshy, Pramod"'

2. Direct Hydrogen Production from Water/Seawater by Irradiation/Vibration-Activated Using Defective Ferroelectric BaTiO3-x Nanoparticles

Author

Jiang, Yue, Toe, Cui Ying, Mofarah, Sajjad S., Cazorla, Claudio, Chang, Shery L. Y., Yin, Yanting, Zhang, Qi, Lim, Sean, Yao, Yin, Tian, Ruoming, Wang, Yuan, Zaman, Tasmia, Arandiyan, Hamidreza, Andersson, Gunther G., Scott, Jason, Koshy, Pramod, Wang, Danyang, and Sorrell, Charles C.

Subjects
Condensed Matter - Materials Science
Abstract

Hydrogen is a promising fossil-fuel alternative fuel owing to its environmentally neutral emissions and high energy density. However, the need for purified water and external power are critical hindrances to implementation of hydrogen production. The present work reveals the potential to overcome these shortcomings through piezo-photocatalysis of seawater using BaTiO3-x (BTO) nanoparticles. This material was made piezoelectrically active by annealing under different atmospheres, including O2, N2, Ar, and H2, the latter of which caused Ti4+ to Ti(4-x)+ multiple reductions and structural expansions that stabilized piezoelectric tetragonal BTO domains. The resultant defect equilibria combine ionic and electron effects, including Ti redox reactions, charge-compensating surface oxygen vacancy formation, and color centre alterations. Further, variety of experimental techniques revealed the effects of reduction on the energy band structure. A strong piezoelectric effect and the presence of self-polarization were confirmed by piezoresponse force microscopy, while simulation work clarified the role of vibration on band bending deriving from the former. The performance data contrasted H2 evolution using deionized (DI) water, simulated seawater, and natural seawater subjected to photocatalysis, piezocatalysis, and piezo-photocatalysis. An efficient H2 evolution rate of 132.4 micromol/g/h was achieved from DI water using piezo-photocatalysis for 5 h. In contrast, piezocatalysis for 2 h followed by piezo-photocatalysis for 3 h resulted in H2 evolution rates of 100.7 micromol/g/h for DI water, 63.4 micromol/g/h for simulated seawater, and 48.7 micromol/g/h for natural seawater. This work provides potential new strategies for large-scale green H2 production using abundant natural resources with conventional piezoelectric material while leveraging the effects of ions dissolved in seawater., Comment: 34 pages, 9 figures

Published
2022

3. Enhancement of Ce and Cr Codopant Solubility and Chemical Homogeneity in TiO2 Nanoparticles through Sol Gel versus Pechini Syntheses

Author

Chen, Wen-Fan, Mofarah, Sajjad S., Hanaor, Dorian Amir Henry, Koshy, Pramod, Chen, Hsin-Kai, Jiang, Yue, and Sorrell, Charles Christopher

Subjects
Condensed Matter - Materials Science
Abstract

Ce/Cr codoped TiO2 nanoparticles were synthesized using sol gel and Pechini methods with heat treatment at 400 C for 4 h. A conventional sol gel process produced well-crystallized anatase, while Pechini synthesis yielded less ordered mixed-phase anatase and rutile; this suggests that the latter method enhances Ce solubility and increases chemical homogeneity but destabilizes the TiO2 lattice. Greater structural disruption from the decomposition of the Pechini precursor formed more open agglomerated morphologies, while the lower levels of structural disruption from pyrolysis of the dried sol gel precursor resulted in denser agglomerates of lower surface areas. Codoping and associated destabilization of the lattice reduced the binding energies in both powders. Cr4+ formation in sol gel powders and Cr6+ formation in Pechini powders suggest that these valence changes derive from synergistic electron exchange from intervalence and/or multivalence charge transfer. Since Ce is too large to allow either substitutional or interstitial solid solubility, the concept of integrated solubility is introduced, in which the Ti site and an adjacent interstice are occupied by the large Ce ion. The photocatalytic performance data show that codoping was detrimental owing to the effects of reduced crystallinity from lattice destabilization and surface area. Two regimes of mechanistic behavior are seen, which are attributed to the unsaturated solid solutions at lower codopant levels and supersaturated solid solutions at higher levels. The present work demonstrates that the Pechini method offers a processing technique that is superior to sol gel because the former facilitates solid solubility and consequent chemical homogeneity.

Published
2022
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13. Low-temperature liquid platinum catalyst

Author

Rahim, Md. Arifur, Tang, Jianbo, Christofferson, Andrew J., Kumar, Priyank V., Meftahi, Nastaran, Centurion, Franco, Cao, Zhenbang, Tang, Junma, Baharfar, Mahroo, Mayyas, Mohannad, Allioux, Francois-Marie, Koshy, Pramod, Daeneke, Torben, McConville, Christopher F., Kaner, Richard B., Russo, Salvy P., and Kalantar-Zadeh, Kourosh

Published
2022
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14. Toughening Mechanisms in Mullite-Based Composites

Author

Koshy, Pramod, primary, Pudadera, Bernadette, additional, Majidi, Tina, additional, Zhong, Vicki, additional, Wong, Vienna C., additional, Zheng, Xiaoran, additional, Ho, Naomi, additional, Cheng, Theodora K.-H., additional, and Sorrell, Charles C., additional

Published
2022
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19. Liquid Metal Doping Induced Asymmetry in Two‐Dimensional Metal Oxides.

Author

Ghasemian, Mohammad B., Zavabeti, Ali, Allioux, Francois‐Marie, Sharma, Pankaj, Mousavi, Maedehsadat, Rahim, Md. Arifur, Khayyam Nekouei, Rasoul, Tang, Jianbo, Christofferson, Andrew J., Meftahi, Nastaran, Rafiezadeh, Somayeh, Cheong, Soshan, Koshy, Pramod, Tilley, Richard D., McConville, Chris F., Russo, Salvy P., Ton‐That, Cuong, Seidel, Jan, and Kalantar‐Zadeh, Kourosh

Published
2024
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20. ROS‐mediated anticancer effects of EGFR‐targeted nanoceria.

Author

Johnson, Kochurani K., Koshy, Pramod, Kopecky, Chantal, Devadason, Michelle, Biazik, Joanna, Zheng, Xiaoran, Jiang, Yue, Wang, Xiaochun, Liu, Yiling, Holst, Jeff, Yang, Jia‐Lin, Kilian, Kristopher A., and Sorrell, Charles C.

Abstract

The therapeutic effectiveness of anticancer drugs, including nanomedicines, can be enhanced with active receptor‐targeting strategies. Epidermal growth factor receptor (EGFR) is an important cancer biomarker, constitutively expressed in sarcoma patients of different histological types. The present work reports materials and in vitro biomedical analyses of silanized (passive delivery) and/or EGF‐functionalized (active delivery) ceria nanorods exhibiting highly defective catalytically active surfaces. The EGFR‐targeting efficiency of nanoceria was confirmed by receptor‐binding studies. Increased cytotoxicity and reactive oxygen species (ROS) production were observed for EGF‐functionalized nanoceria owing to enhanced cellular uptake by HT‐1080 fibrosarcoma cells. The uptake was confirmed by TEM and confocal microscopy. Silanized nanoceria demonstrated negligible/minimal cytotoxicity toward healthy MRC‐5 cells at 24 and 48 h, whereas this was significant at 72 h owing to a nanoceria accumulation effect. In contrast, considerable cytotoxicity toward the cancer cells was exhibited at all three times points. The ROS generation and associated cytotoxicity were moderated by the equilibrium between catalysis by ceria, generation of cell debris, and blockage of active sites. EGFR‐targeting is shown to enhance the uptake levels of nanoceria by cancer cells, subsequently enhancing the overall anticancer activity and therapeutic performance of ceria. [ABSTRACT FROM AUTHOR]

Published
2024
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25. Development and characterisation of ultra-high temperature ceramics (UHTCs) for extreme operating conditions.

Author

Wong, Vienna C., Holmes, Rohan, Muránsky, Ondrej, Koshy, Pramod, Sorrell, Charles C., Slater, Sonya L., and Wood, Christopher A.

Subjects
ULTRA-high-temperature ceramics, COVALENT bonds, HIGH temperatures, ZIRCONIUM boride, LOW temperatures
Abstract

Zirconium diboride (ZrB2), an ultra-high temperature ceramic (UHTC) is characterised by its combination of metallic and covalent bonding which confers high strength and a high melting temperature (>2500°C). These thermo-physical-mechanical properties coupled with the strong covalent bonding and low intrinsic self-diffusivity result in excellent high-temperature performance suitable for various energy, space, and defence applications; however, owing to these characteristics, UHTCs typically require elevated temperatures and pressures for consolidation. This work investigates the effect of consolidation temperature and dwell time on the microstructural development and density of zirconium diboride (ZrB2) fabricated via spark-plasma sintering (SPS). It was observed that increasing consolidation temperatures resulted in higher bulk densities (72.2% (1900°C), 95.2% (1950°C), 96.4% (1980°C), and 97.1% (2000°C)). Poor densification at 1900°C was attributed to insufficient thermal energy limiting gain boundary and lattice diffusion and grain boundary sliding whilst beyond 1950°C, density appeared to stabilise accompanied by residual intragranular porosity arising from grain coarsening. Extended dwell times at a lower temperature (1900°C), resulted in increased density, but substantial residual apparent porosity was measured (16-20%) for dwell times of 5 min, 10 min, and 20 min. At a higher temperature (1950°C), this effect diminished with modest (<0.5%) density increases for longer dwell times. Elevated temperatures had a more pronounced effect on densification compared to extended dwell times due to the former's impact on enhancing diffusion mechanisms. [ABSTRACT FROM AUTHOR]

Published
2024

27. ROS‐mediated anticancer effects of EGFR‐targeted nanoceria

Author

Johnson, Kochurani K., primary, Koshy, Pramod, additional, Kopecky, Chantal, additional, Devadason, Michelle, additional, Biazik, Joanna, additional, Zheng, Xiaoran, additional, Jiang, Yue, additional, Wang, Xiaochun, additional, Liu, Yiling, additional, Holst, Jeff, additional, Yang, Jia‐Lin, additional, Kilian, Kristopher A., additional, and Sorrell, Charles C., additional

Published
2023
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29. Effect of Ti‐metal addition on hot‐isostatically pressed (HIPed) Synroc‐C.

Author

Farzana, Rifat, Dayal, Pranesh, Peristyy, Anton, Sutton, Phillip, Aly, Zaynab, Aughterson, Robert D., Nguyen, Thanh Ha, Yeoh, Michelle, Koshy, Pramod, and Gregg, Daniel J.

Subjects
ISOSTATIC pressing, HOT pressing, WASTE treatment, FUEL cycle, NUCLEAR fuels, RADIOACTIVE wastes
Abstract

Synroc, a candidate nuclear wasteform and Synroc technology, a waste treatment solution utilizing hot‐isostatic pressing (HIPing) have significant potential for the immobilisation of challenging nuclear wastes from both current and innovative reactors and fuel cycles. Hot isostatic press (HIP) consolidation is undertaken within sealed metal HIP canisters, where metal buffers (e.g., Ti, Fe and Ni) can be incorporated to control the redox environment within the canister. This study, for the first time, reports the effect of varying Ti‐metal addition (0, 2, 4, and 8 wt.%) on phase formation, microstructural characteristics, and wasteform performance for HIP consolidated Synroc‐C containing 20 wt.% simulated PUREX type (PW‐4b) high level waste. Quantitative X‐ray diffraction analysis, scanning electron microscopy‐energy dispersive X‐ray spectroscopy (EDS) and transmission electron microscopy‐EDS analyses were undertaken for analytical investigations. The chemical durability of the samples was assessed using ASTM C1220‐21 standard test. Hot‐isostatically pressed (HIPed) samples with 0 and 8 wt.% Ti added for redox control produced unfavourable phase formation. However, the HIPed samples with Ti additions of 2 and 4 wt.% as a redox buffer showed the desired phase formation of Synroc‐C without any significant change to the partitioning of waste elements among the phases along with compatible durability results, when compared to previous literature for hot uniaxial pressing (HUPed) or sintered materials. [ABSTRACT FROM AUTHOR]

Published
2023
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32. Stacking Faults Defect-Rich MoNi Alloy for Ultrahigh-Performance Hydrogen Evolution

Author

Wang, Yuan, primary, Arandiyan, Hamidreza, additional, Mofarah, Sajjad S., additional, Shen, Xiangjian, additional, Bartlett, Stuart, additional, Koshy, Pramod, additional, Sorrell, Charles, additional, Sun, Hongyu, additional, Pozo-Gonzalo, Cristina, additional, Dastafkan, Kamran, additional, Britto, Sylvia, additional, Bhargava, Suresh, additional, and Zhao, Chuan, additional

Published
2023
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34. Unveiling the mechanisms behind surface degradation of dental resin composites in simulated oral environments.

Author

Leung, Brenda Ah-yan, Joe, William, Mofarah, Sajjad S., Sorrell, Charles C., Abbasi, Roozbeh, Azadeh, Mohsen, Arsecularatne, Joseph A, and Koshy, Pramod

Abstract

Dental resin composites are widely used as restorative materials due to their natural aesthetic and versatile properties. However, there has been limited research on the degradation mechanisms of these composites in gastric acid environments, which would be common in patients with gastroesophageal reflux. This study aims to investigate the degradation behavior of dental composites immersed in simulated oral environments, including acid, saliva, and water. Mechanical and morphological properties of the composites, upon immersion in the simulated environments, were thoroughly examined using hardness testing and SEM imaging. Qualitative analyses of the ions leached from the polymer matrix and fillers were conducted using XPS and ICP-MS. In addition, the thermodynamic stability of the inorganic fillers of the composites in aqueous solutions across a wide range of pH values was theoretically studied through construction of Pourbaix diagrams. This study proposed a mechanism for composite leaching involving interactions between the matrix's hydrophilic groups and the aqueous immersion media, leading to swelling and chemical degradation of the composites. Furthermore, it was demonstrated that filler leaching was followed by ion exchange with Ca and P, resulting in the formation of hard calcified layers on the composite surface. The current findings provide valuable insights into the development of new composite materials with improved durability and resistance to degradation, especially for patients suffering from gastroesophageal reflux. [ABSTRACT FROM AUTHOR]

Published
2023
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35. Efficient Cocatalyst-Free Piezo-Photocatalytic Hydrogen Evolution of Defective BaTiO3–x Nanoparticles from Seawater

Author

Jiang, Yue, primary, Toe, Cui Ying, additional, Mofarah, Sajjad S., additional, Cazorla, Claudio, additional, Chang, Shery L.Y., additional, Yin, Yanting, additional, Zhang, Qi, additional, Lim, Sean, additional, Yao, Yin, additional, Tian, Ruoming, additional, Wang, Yuan, additional, Zaman, Tasmia, additional, Arandiyan, Hamidreza, additional, Andersson, Gunther G., additional, Scott, Jason, additional, Koshy, Pramod, additional, Wang, Danyang, additional, and Sorrell, Charles C., additional

Published
2023
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36. A comprehensive review of cathode materials for Na–air batteries

Author

Mao, Pengcheng, primary, Arandiyan, Hamidreza, additional, Mofarah, Sajjad S., additional, Koshy, Pramod, additional, Pozo-Gonzalo, Cristina, additional, Zheng, Runguo, additional, Wang, Zhiyuan, additional, Wang, Yuan, additional, Bhargava, Suresh K., additional, Sun, Hongyu, additional, Shao, Zongping, additional, and Liu, Yanguo, additional

Published
2023
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37. Recent Advances in In-situ and Operando Characterization Techniques for Li7La3Zr2O12-Based Solid-State Lithium Batteries

Author

Zhang, Lei, primary, Fan, Huilin, additional, Dang, Yuzhen, additional, Zhuang, Quanchao, additional, Arandiyan, Hamidreza, additional, Wang, Yuan, additional, Cheng, Ningyan, additional, Sun, Hongyu, additional, Perez Garza, Hector Hugo, additional, Zheng, Runguo, additional, Wang, Zhiyuan, additional, Mofarah, Sajjad S., additional, Koshy, Pramod, additional, Bhargava, Suresh Kumar, additional, Cui, Yanhua, additional, Shao, Zongping, additional, and Liu, Yanguo, additional

Published
2023
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39. Liquid metal synthesis solvents for metallic crystals

Author

Idrus-Saidi, Shuhada A., primary, Tang, Jianbo, additional, Lambie, Stephanie, additional, Han, Jialuo, additional, Mayyas, Mohannad, additional, Ghasemian, Mohammad B., additional, Allioux, Francois-Marie, additional, Cai, Shengxiang, additional, Koshy, Pramod, additional, Mostaghimi, Peyman, additional, Steenbergen, Krista G., additional, Barnard, Amanda S., additional, Daeneke, Torben, additional, Gaston, Nicola, additional, and Kalantar-Zadeh, Kourosh, additional

Published
2022
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45. Microfluidic device with a carbonate‐rich hydroxyapatite micro‐coating

Author

Lui, Florence H. Y., primary, Xu, Liangcheng, additional, Michaux, Pierrette, additional, Biazik, Joanna, additional, Harm, Gregory F. S., additional, Oliver, Rema A., additional, Koshy, Pramod, additional, Walsh, William R., additional, Mobbs, Ralph J., additional, Brennan‐Speranza, Tara C., additional, Wang, Yu, additional, You, Lidan, additional, and Sorrell, Charles C., additional

Published
2022
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46. Production of Antibacterial Activity and Bone Cell Proliferation by Surface Engineering of Ga‐ or Mn‐Doped Ceria‐Coated Biomedical Titanium Alloy

Author

Khosravanihaghighi, Ayda, primary, Koshy, Pramod, additional, Yasir, Muhammad, additional, Romanazzo, Sara, additional, Lovric, Vedran, additional, Kilian, Kristopher Alan, additional, Willcox, Mark Duncan, additional, Walsh, William Robert, additional, and Sorrell, Charles Christopher, additional

Published
2022
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