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Physical Sciences and Mathematics Commons™

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Physics

Western Michigan University

2019

Articles 1 - 7 of 7

Full-Text Articles in Physical Sciences and Mathematics

Synthesis And Characterization Of Ion-Implanted Gold Nanoparticles, Nurlathifah Fnu Dec 2019

Synthesis And Characterization Of Ion-Implanted Gold Nanoparticles, Nurlathifah Fnu

Masters Theses

Gold negative ions of 70 keV energy were implanted within the quartz substrates at room temperature at seven different fluences starting from 2 x 1016 particles/cm2 to 8 x 1016 particles/cm2 with the increment of 1 x 1016. Prior to the implantation, Stopping and Range of Ions in Matter (SRIM) calculations were carried to obtain the Bragg peak below the surface of quartz. Rutherford Backscattering Spectrometry (RBS) was carried out using 2.0 MeV He++ ions to measure depth and implanted fluence of gold, and learn how they varied with fluence. Backscattered He particles …

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Embedded Silver Nanoparticles For Metal Enhanced Photoluminescence, Shahid Iqbal Dec 2019

Embedded Silver Nanoparticles For Metal Enhanced Photoluminescence, Shahid Iqbal

Dissertations

Imaging of biologically significant molecules using plasmons of Metal Nanoparticles (MNPs) is gaining attention in the research community. Localized Surface Plasmon Resonance (LSPR) is the coherent oscillation of conduction electrons of MNPs. The biologically significant molecule is labeled with the fluorophore molecule to get the image. This approach is widely used in clinical practices, however, low intensity light emission from the labeled molecule makes it difficult to image the biologically significant material. One way to improve the weak intensities of fluorophore is to enhance the brightness using a process called Metal Enhanced Photoluminescence (MEP). This phenomenon occurs in the close …

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Simultaneous X-Ray Emission Accompanying Two Electron Capture For Fluorine On Gas Targets, David S. La Mantia Dec 2019

Simultaneous X-Ray Emission Accompanying Two Electron Capture For Fluorine On Gas Targets, David S. La Mantia

Dissertations

The collision between a charged ion and an atom resulting in the capture of two electrons, simultaneous with the emission of a single photon is referred to as radiative double electron capture (RDEC). For ion-atom collisions, this process can be considered the inverse of double photoionization. The study of either process, where just two electrons are involved without influence from neighboring electrons, promises new insight into electron correlation and the role it plays in quantum mechanics. Such a study for photoionization has not yet been done experimentally for two-electron ions because the only target system for which two electrons are …

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Fostering Computational Thinking In An Introductory Physics Lab, Diana Sachmpazidi Sep 2019

Fostering Computational Thinking In An Introductory Physics Lab, Diana Sachmpazidi

STEM Instructional Graduate Teaching Assistant Posters

•Thinking computationally means conceptualizing a problem and formulating it in a way that a computer can solve it (Wing, 2010). •Computational Thinking (CT) is the third pillar of the scientific method along with theory and experimentation and is a fundamental skill that K-12 students and undergraduates should be equipped with (Wing, 2016; 2006). •Research on CT has only been active the last 10 years and most studies are still at the stage of ideas (Kalelioglu et al., 2016). •The integration of CT aspects in instruction is a widely expanding phenomenon in physics classrooms in the context of higher education, and …

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Investigation Of Structural, Optical And Electronic Properties Of Modified Methylammonium Lead Iodide Perovskites, Rasanjali Jayathissa Aug 2019

Investigation Of Structural, Optical And Electronic Properties Of Modified Methylammonium Lead Iodide Perovskites, Rasanjali Jayathissa

Dissertations

Owing to their high-power conversion efficiency (PCE), easy processability, and low fabrication cost, organic lead halide perovskites (OLHP) are emerging as a most promising photovoltaic technology. However, toxicity of lead (Pb) is a major concern for further development. Therefore, it is essential to explore nontoxic metals to replace lead in these materials. In the current research work, nontoxic Mn2+, Na+ and Ba2+ are doped at 1, 5 and 10% mole concentrations to partially substitute Pb2+ in methyl ammonium lead iodide (CH3NH3PbI3 or MAPbI3) perovskite systems, and the effects …

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Sensitivity Of The Theoretical Electron Capture Shape And Comparisons To Experiment, Katrina E. Koehler Jun 2019

Sensitivity Of The Theoretical Electron Capture Shape And Comparisons To Experiment, Katrina E. Koehler

Dissertations

The direct neutrino mass is a fundamental physics quantity with far-reaching implications for the physics community. Current experimental limits put the direct neutrino mass at less than 2 eV. The neutrino mass can be explored through an end-point measurement of tritium beta decay, which is currently underway in the KArlsruhe TRItium Neutrino experiment (KATRIN). KATRIN has a lower limit of 0.2 eV, at which point there will be either a mass measurement or another upper bound. In either case, an alternative experiment with different systematics is needed to verify the results and/or push the upper bound lower. The end point …

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Radiative Double Electron Capture By Ions In Collisions With Gas Targets, Charles Taylor Apr 2019

Radiative Double Electron Capture By Ions In Collisions With Gas Targets, Charles Taylor

Honors Theses

Radiative double electron capture (RDEC) is a two-step quantum process where two electrons are captured from the target gas to the projectile ion beam with a simultaneous emission of a single photon. The projectile ion beam was obtained from the tandem Van de Graaff accelerator at Western Michigan University. The projectile beam used is fully and partially ionized fluorine 9+, and 8+ in collision with highly pure nitrogen gas. The objective of the research is to observe RDEC from x ray detection using time to amplitude converters (TACs) that look for coincidences between x rays and particles. The signal from …

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