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Item Enhancing controlled and uniform degradation of Fe by incorporating Mg and Zn aimed for bio-degradable material applications(Elsevier, 2022-06-01) Maruf, Mahbub Alam; Noor-A-Alam, Mohammed; Haider, Waseem; Shabib, Ishraq; IUPUC Mechanical EngineeringIn this study, combinatorial development of three nanostructured thin film systems, i.e., Fe87Mg9Zn4 (FMZ-1), Fe74Mg19Zn7 (FMZ-2), and Fe60Mg30Zn10 (FMZ-3), are employed via magnetron sputtering and their degradation pattern is studied in Phosphate Buffered Saline (PBS) solution. Controlled and uniform degradation of Fe is observed with the addition of Mg and Zn, which are crucial for temporary biodegradable implants. The structural characterization of the three samples demonstrates a crystalline structure of Fe87Mg9Zn4, a partially amorphous structure of Fe74Mg19Zn7, and a substitutional solid solution of bcc-Fe-Mg in Fe60Mg30Zn10 sample. Potentiodynamic polarization test reveals higher degradation tendency with the addition of Mg and Zn in the samples compared to pure Fe, as validated by more negative corrosion potentials and higher corrosion current densities. Samples with higher Mg and Zn contents (FMZ-2 and FMZ-3) exhibiting lower charge transfer resistance, as extracted from electrochemical impedance spectroscopy (EIS), also indicates higher corrosion rate compared to Pure Fe. Time-dependent EIS demonstrates gradual decrease in impedance values, representing controlled degradation of the samples upon exposure in PBS solution. Scanning Electron Microscopy (SEM) confirms uniform degradation pattern of FMZ-2 and FMZ-3 samples compared to FMZ-1 after 12 h and 24 h immersion in PBS solution. Finally, the X-ray Photoelectron Spectroscopy (XPS) depicts the formation of oxides, hydroxides, and phosphates of Fe, Mg, and Zn as corrosion products. The higher degradation tendency of the co-sputtered samples is ascribed to the combined role of chemical composition and non-equilibrium nanostructures.Item Pseudocapacitive contribution in amorphous FeVO4 cathode for lithium-ion batteries(Wiley, 2022) Liu, Tianwei; Liu, Yadong; Niu, Chaoqun; Chao, Zi-Sheng; Mechanical and Energy Engineering, School of Engineering and TechnologyAmorphous iron vanadate (FeVO4 ) nanoparticle cathode materials are successfully synthesized through a facile, efficient, and highyielding ion exchange-liquid precipitation method. The composition, structure, morphology, surface area, and electrochemical performances of the synthesized materials have been characterized by the Thermogravimetric-Differential scanning calorimetry (TGDSC), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photon spectroscopy (XPS), Brunauer?Emmet?Teller (BET), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. The electrochemical performance results indicate that the amorphous FeVO4 delivers a specific capacity as high as 275 mAh g-1 at 0.1 C in a voltage range of 1.5?4.5 V. The excellent electrochemical performances can be ascribed to the pseudocapacitive behavior. The systematic kinetic analysis demonstrates that the pseudocapacitive charge storage allows the amorphous FVO cathode delivering the excellent high specific capacity.Item Unattached(2015) Connelly, Carly; Hull, GregI am anxiously aware of human vulnerability; the brevity of living and the impermanence of the present. There is a prism of experience in the complexity of life and death through which my work is influenced. Nothing is a direct reproduction of reality but rather, a reformed, reshaped and restored version of its past. My work imitates subconscious fears, passions, and relationships with a world that provides both destruction and renewal; the dichotomy of pain and pleasure in life in many ways informs the understanding of self and identity - but it does not define it. The work blurs between reality and fantasy, exposure and repression, surface and structure, eternity and the ephemeral. I transform materials and blend processes to create mixed media sculptures and installations that respond to space, form, and compositional relationships that re-examine my own existence and serves as a self-portrait.