Open Access. Powered by Scholars. Published by Universities.®
- Publication Type
Articles 1 - 10 of 10
Full-Text Articles in Physics
Conditions For Super-Adiabatic Droplet Growth After Entrainment Mixing, Fan Yang, Raymond Shaw, Huiwen Xue
Conditions For Super-Adiabatic Droplet Growth After Entrainment Mixing, Fan Yang, Raymond Shaw, Huiwen Xue
Michigan Tech Publications
Cloud droplet response to entrainment and mixing between a cloud and its environment is considered, accounting for subsequent droplet growth during adiabatic ascent following a mixing event. The vertical profile for liquid water mixing ratio after a mixing event is derived analytically, allowing the reduction to be predicted from the mixing fraction and from the temperature and humidity for both the cloud and environment. It is derived for the limit of homogeneous mixing. The expression leads to a critical height above the mixing level: at the critical height the cloud droplet radius is the same for both mixed and unmixed …
Surface Effect Of Ferromagnetic Nanoparticles On Transition Between Single- And Multi-Domain Structure Or Between Single-Domain Structure And Superparamagnetic Phase, Hind Adawi
Browse all Theses and Dissertations
Surface effects on critical dimensions of ferromagnetic nanoparticles were studied. Algebraic equations were derived and numerically solved for critical radius RC2 of ferromagnetic nanoparticles describing the transition between single- and multi-domain magnetic structure. Results were analyzed to illustrate the effect of surface parameters related to saturation magnetization a, exchange interaction ß, and anisotropy KS on the critical radius of nanoparticles with a core value of anisotropy KV. Available experimental data for MnBi, FePt, and CoPt or for Fe nanoparticles were used as examples of nanoparticles with high and low values of KV, respectively. Our studies clearly show that discrepancies existing …
Social Network Analysis And The Representation Of Female Students In Introductory Undergraduate Physics, Sarah Teresa Hierath
Social Network Analysis And The Representation Of Female Students In Introductory Undergraduate Physics, Sarah Teresa Hierath
Browse all Theses and Dissertations
Physics Education Research has begun to focus on the learning habits, success, and connections of students in physics classrooms using Social Network Analysis (SNA). SNA is an important tool in studying classroom dynamics because it can be used to map the social structure of a classroom's interactions and to aid in understanding how students work and study together. This study presents network diagrams, statistics, centrality measures, and conceptual understanding correlations for 7 different sections of introductory physics. Centrality measures were determined from a first and last week survey in which students were asked to indicate their study partners within the …
Terahertz Spectroscopic Breath Analysis As A Viable Analytical Chemical Sensing Technique, Robert M. Schueler
Terahertz Spectroscopic Breath Analysis As A Viable Analytical Chemical Sensing Technique, Robert M. Schueler
Browse all Theses and Dissertations
The ability to quantify trace chemicals in human breath enables the possibility of identifying breath biomarkers to aid in diagnosis. The vast majority of the studies in the analytical breath analysis rely on GC-MS techniques for quantification of the human breath composition1,2,3,4. THz spectroscopy of breath is rapid, sensitive, and highly specific molecular identification in complex mixtures containing 10-100 analytes with near `absolute' specificity. THz spectroscopic breath analyzers require chemical preconcentration. A newly developed custom preconcentrator was constructed and compared in its performance to a commercial system. Unlike the commercial counterpart, the new system does not require cryogenic liquids, is …
A Social Network Analysis Of An Introductory Calculus-Based Physics Class With Comparisons Of Traditional And Non-Traditional Students, Fci Scores, And Network Centralities, Emily Sandt
Browse all Theses and Dissertations
The use of social network analysis in physics education research seeks to advance understanding of how students' collaborative tendencies influence trends of learning. Common useful measurements are network size, density of connections, and centrality measures that describe the importance of nodes' positions. This study compared four different centrality measures at the beginning and end of seven sections of an introductory calculus-based physics course. The Force Concept Inventory was used as a measure of conceptual learning at pre- and post-course administrations. The main focus of this study was to identify if differences in network centralities and conceptual learning/knowledge exist with respect …
Correlations Between Introductory Students’ Attitudes About Physics And Conceptual Understanding, Raym Alzahrani
Correlations Between Introductory Students’ Attitudes About Physics And Conceptual Understanding, Raym Alzahrani
Browse all Theses and Dissertations
The purpose of this study is to measure correlations between the students’ incoming attitudes, beliefs and expectations about physics and their conceptual understanding. The study presents a profile of the attitudes and beliefs for Wright State University students who enrolled in calculus-based General Physics I courses during academic years 2014-2015 and 2015-2016. Students’ initial and final attitudes, measured using the CLASS, are correlated with initial and final conceptual gain, measured using the Force Concept Inventory. Students’ initial attitudes (Opre) was correlated with students’ gain (FCIgain) in many sections. Correlations between students’ final attitudes (Opost) and their conceptual understanding (FCIpost), reported …
High Powered Pulsed Terahertz Light Generation From Superconducting Antenna Arrays, Nicholas C. Padgett
High Powered Pulsed Terahertz Light Generation From Superconducting Antenna Arrays, Nicholas C. Padgett
Browse all Theses and Dissertations
Terahertz radiation is invaluable for use in spectroscopy and imaging work due to its nondestructive nature. It has become a key focus for those wishing to develop sensors capable of detecting weapons and narcotics unobtrusively and at a distance as well as characterizing materials and identifying defects. An ultrafast pulsed (femtoseconds) laser incident on a superconducting ring has been predicted to cause the emission of terahertz (THz) radiation. It is theorized that the radiation is a result of the supercurrent being modulated by the breaking and recombining of Cooper pairs on the order of picoseconds, where the time scale determines …
Millimeter – Wave/Terahertz Chirped Michelson Interferometer Techniques For Sub Surface Sensing, Dinesh Amal Mirando
Millimeter – Wave/Terahertz Chirped Michelson Interferometer Techniques For Sub Surface Sensing, Dinesh Amal Mirando
Browse all Theses and Dissertations
Over the last couple of decades, the field of millimeter-wave (mmW) and terahertz (THz) radiation has seen an accelerated growth thanks to developments in high quality mmW/THz sensors. These developments have contributed to many useful applications in the fields of medicine, security, construction, etc. Non-destructive evaluations such as the detection of defects in materials is currently one of the major applications of mmW/THz radiation. These evaluations are performed using mmW/THz continuous-wave radar systems. In this study, we discuss how Frequency Modulated Continuous Wave (FMCW) techniques can enhance sensing applications through the use of a Michelson interferometer. This allows multiple objects …
Heating Power Of Coated Fecov Magnetic Nanoparticles, Hanaa Ali Alshammari
Heating Power Of Coated Fecov Magnetic Nanoparticles, Hanaa Ali Alshammari
Browse all Theses and Dissertations
The effect of coatings on the heating curves of magnetic nanoparticles was studied in this Thesis. Iron cobalt vanadium (FeCoV) nanoparticles with oxide (CoOFe2O3) and graphite (C) coating to prevent oxidation, were synthesized through thermal plasma processing method. The magnetic nanoparticles had an average diameter of 30 nm. In the case of FeCoV with oxide coating, the initial diameter of the pure FeCoV nanoparticles on average was 30 nm but after oxidation 5 nm thick oxide layer was created. As a result of this oxidation, the magnetic core of FeCoV nanoparticles was shrunk from 30 nm to 20 nm in …
Use Of Clearview Gel Dosimeter For Quality Assurance And Testing Of Stereotactic Radiosurgery, Erik Joseph-Leonard Courter
Use Of Clearview Gel Dosimeter For Quality Assurance And Testing Of Stereotactic Radiosurgery, Erik Joseph-Leonard Courter
Browse all Theses and Dissertations
There exists a lack of accurate, reproducible three-dimensional dosimetry techniques for stereotactic radiosurgery (SRS) commissioning and quality assurance. This experiment evaluates the use of ClearView gel dosimeters as an alternative to current methods for small field dosimetry in SRS testing. ClearView differs from other gel dosimeters in that it uses tetrazolium salt in its chemical make-up in place of traditional Fricke-type compounds. Using a Varian TrueBeam radiotherapy system to deliver the radiation, three vials of ClearView gel dosimeter were tested in three different dose delivery scenarios. The first test examined the dosimeter's response to a static beam with the dose …