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2018

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Articles 61 - 66 of 66

Full-Text Articles in Physics

Real Time Spectroscopic Ellipsometry Analysis Of First Stage Cuin1-Xgaxse2 Growth: Indium-Gallium Selenide Co-Evaporation, Puja Pradhan, Puruswottam Aryal, Dinesh Attygalle, Abdel-Rahman Ibdah, Prakash Koirala, Jian Li, Khagendra P. Bhandari, Geethika K. Liyanage, Randy J. Ellingson, Michael J. Heben, Sylvain Marsillac, Robert W. Collins, Nikolas J. Podraza Jan 2018

Real Time Spectroscopic Ellipsometry Analysis Of First Stage Cuin1-Xgaxse2 Growth: Indium-Gallium Selenide Co-Evaporation, Puja Pradhan, Puruswottam Aryal, Dinesh Attygalle, Abdel-Rahman Ibdah, Prakash Koirala, Jian Li, Khagendra P. Bhandari, Geethika K. Liyanage, Randy J. Ellingson, Michael J. Heben, Sylvain Marsillac, Robert W. Collins, Nikolas J. Podraza

Electrical & Computer Engineering Faculty Publications

Real time spectroscopic ellipsometry (RTSE) has been applied for in-situ monitoring of the first stage of copper indium-gallium diselenide (CIGS) thin film deposition by the three-stage co-evaporation process used for fabrication of high efficiency thin film photovoltaic (PV) devices. The first stage entails the growth of indium-gallium selenide (In1-xGax)₂Se₃ (IGS) on a substrate of Mo-coated soda lime glass maintained at a temperature of 400 °C. This is a critical stage of CIGS deposition because a large fraction of the final film thickness is deposited, and as a result precise compositional control is desired in order to …


Transient Lattice Deformations Of Crystals Studied By Means Of Ultrafast Time-Resolved X-Ray And Electron Diffraction, Runze Li, Kyle Sundqvist, Jie Chen, H. E. Elsayed-Ali, Jie Zhang, Peter M. Rentzepis Jan 2018

Transient Lattice Deformations Of Crystals Studied By Means Of Ultrafast Time-Resolved X-Ray And Electron Diffraction, Runze Li, Kyle Sundqvist, Jie Chen, H. E. Elsayed-Ali, Jie Zhang, Peter M. Rentzepis

Electrical & Computer Engineering Faculty Publications

Ultrafast lattice deformation of tens to hundreds of nanometer thick metallic crystals, after femtosecond laser excitation, was measured directly using 8.04 keV subpicosecond x-ray and 59 keV femtosecond electron pulses. Coherent phonons were generated in both single crystal and polycrystalline films. Lattice compression was observed within the first few picoseconds after laser irradiation in single crystal aluminum, which was attributed to the generation of a blast force and the propagation of elastic waves. The different time scales of lattice heating for tens and hundreds nanometer thick films are clearly distinguished by electron and x-ray pulse diffraction. The electron and lattice …


Plasma Medicine: A Brief Introduction, Mounir Laroussi Jan 2018

Plasma Medicine: A Brief Introduction, Mounir Laroussi

Electrical & Computer Engineering Faculty Publications

This mini review is to introduce the readers of Plasma to the field of plasma medicine. This is a multidisciplinary field of research at the intersection of physics, engineering, biology and medicine. Plasma medicine is only about two decades old, but the research community active in this emerging field has grown tremendously in the last few years. Today, research is being conducted on a number of applications including wound healing and cancer treatment. Although a lot of knowledge has been created and our understanding of the fundamental mechanisms that play important roles in the interaction between low temperature plasma and …


Magnetron Sputtering Of Nb3Sn For Srf Cavities, Md. N. Sayeed, H. Elsayed-Ali, G. V. Eremeev, M. J. Kelley, U. Pudasaini, C. E. Reece Jan 2018

Magnetron Sputtering Of Nb3Sn For Srf Cavities, Md. N. Sayeed, H. Elsayed-Ali, G. V. Eremeev, M. J. Kelley, U. Pudasaini, C. E. Reece

Electrical & Computer Engineering Faculty Publications

Nb3Sn is a potential candidate for surface material of SRF cavities since it can enable the cavity to operate at higher temperatures with high quality factor and at an increased accelerating gradient. Nb-Sn films were deposited using magnetron sputtering of individual Nb and Sn targets onto Nb and sapphire substrates. The as-deposited films were annealed at 1200 °C for 3 hours. The films were characterized for their structure by X-ray Diffraction (XRD), morphology by Field Emission Scanning Electron Microscopy (FESEM), and composition by Energy Dispersive X-ray Spectroscopy (EDS) and Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS). The …


Effects Of Light Reflection On Spatial Visualization Ability And Implications For Engineering Technology Students, Petros Katsioloudis, Mildred Jones Jan 2018

Effects Of Light Reflection On Spatial Visualization Ability And Implications For Engineering Technology Students, Petros Katsioloudis, Mildred Jones

STEMPS Faculty Publications

Results from a number of studies indicate that the type of light generated by the reflection on the surface of different types of surfaces can influence the spatial visualization ability; however, research provides inconsistent results. Considering this, a quasi-experimental study was conducted to identify the existence of statistically significant effects on spatial visualization ability as measured by the Mental Cutting Test and Sectional View drawing ability due to the impacts of light reflection. In particular, the study compared three types of light reflection; mirror, specular and diffuse and whether a significant difference exists among engineering technology students. According to the …


Learning Local, Quenched Disorder In Plasticity And Other Crackling Noise Phenomena, Stefanos Papanikolaou Jan 2018

Learning Local, Quenched Disorder In Plasticity And Other Crackling Noise Phenomena, Stefanos Papanikolaou

Faculty & Staff Scholarship

When far from equilibrium, many-body systems display behavior that strongly depends on the initial conditions. A characteristic such example is the phenomenon of plasticity of crystalline and amorphous materials that strongly depends on the material history. In plasticity modeling, the history is captured by a quenched, local and disordered flow stress distribution. While it is this disorder that causes avalanches that are commonly observed during nanoscale plastic deformation, the functional form and scaling properties have remained elusive. In this paper, a generic formalism is developed for deriving local disorder distributions from field- response (e.g., stress/strain) timeseries in models of crackling …