Computational Analysis of the Maximum Optical Enhancement of Gold Nanowires and Nanowire Arrays

Plasmonic devices have gained popularity recently due to their unique ability to focus light to scales smaller than the diffraction limit and amplify the intensity of incident light. One such plasmonic device is the gold nanowire, a simple geometry that can be fabricated into a variety of geometric patterns. The aim of this project was to determine the effect of nanowire geometry on its maximum optical enhancement. For this purpose, the plasmonic optical enhancement properties of single gold nanowires and triple nanowire arrays were investigated using finite element method simulations. The results of the simulations indicate a significant effect on the optical enhancement of both the thickness and width of the nanowires. From the simulation data, an equation for each geometry (single and triple array) was found that relates the dimensions and incident wavelength to the optical enhancement. These equations can be used while designing nanowires to optimize the dimensions and provide the maximum possible optical enhancement

Teaching Economics Principles as Part of Development Studies

SUMMARY The article starts from the proposition that present divisions in the subject of economics, its practice and teaching, are due to the existence of fundamental irreconcilable differences, which can be characterised as alternative theories of value. Three such theories are briefly outlined; the subjective preference theory which starts from the proposition of individual utility maximisation and logically derives monetarist policy; cost of production theory which sees the complex technical interrelationships of industrial society as demanding active, detailed state intervention to regulate and coordinate; and abstract labour theory, with the tensions of class struggle finding their reflection in political activity and threatening the position of the commodity relationship as the basis of social existence under capitalism. The authors suggest that teaching economics principles would be better organised if these different theories of value were taught sequentially as internally consistent rival schools of thought. RESUME L'enseignement des principes économiques dans le cadre des études sur le développement L'article part de la proposition que les divisions actuelles dans l'étude de l'économie, sa pratique et son enseignement sont dues à l'existence de différences fondamentales irréconciliables qui peuvent être caractérisées comme des théories de valeur rivales. Trois de ces théories sont brièvement décrites; la théorie de la préférence subjective qui part de la proposition de la maximisation de l'utilité individuelle et aboutit logiquement à une politique monétaire; la théorie du coût de production qui considère que les interrelations techniques complexes de la société industrielle exigent une intervention de l'état active et détaillée pour assurer une direction et une coordination; et la théorie abstraite du travail, selon laquelle les tensions de la lutte de classe se reflètent dans l'activité politique et menacent la position du rapport des marchandises comme base de l'existence sociale sous un régime capitaliste. Les auteurs suggèrent que l'enseignement des principes économiques serait mieux organisé si ces différentes théories de valeur étaient enseignées en séquence comme étant des écoles de pensée rivales et intérieurement conséquentes. RESUMEN Enseñanza de los principios económicos como parte de los estudios de desarrollo El artículo comienza declarando que las divisiones actuales del tema de economía, su práctica y enseñanza, se deben a la existencia de diferencias fundamentales irreconciliables que se pueden caracterizar como teorías alternativas del valor. Se reseñan brevemente tres de dichas teorías: la teoría de preferencia subjetiva que comienza basándose en la maxi?mización de la utilidad individual y lógicamente deriva en la política monetarista; la teoría sobre costo de producción que contempla las complejas relaciones técnicas de la sociedad industrial como una exigencia activa y detallada en favor de la intervención estatal para la reglamentación y coordinación; y la teoría abstracta del trabajo, con las tensiones creadas por la lucha de clases que se reflejan en la actividad política y amenazan la posición de la relación entre productos básicos como la base de la existencia social bajo el capitalismo. Los autores sugieren que la enseñanza de los principios económicos podría organizarse mejor si se enseñasen estas diversas teorías del valor de manera consecutiva como escuelas rivales de ideas con consistencia interna

Senior Recital: Catherine Flinchum, flute

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Ms. Flinchum studies flute with Christina Smith.https://digitalcommons.kennesaw.edu/musicprograms/1510/thumbnail.jp

High precision quantum control of single donor spins in silicon

The Stark shift of the hyperfine coupling constant is investigated for a P donor in Si far below the ionization regime in the presence of interfaces using Tight-binding and Band Minima Basis approaches and compared to the recent precision measurements. The TB electronic structure calculations included over 3 million atoms. In contrast to previous effective mass based results, the quadratic Stark coefficient obtained from both theories agrees closely with the experiments. This work represents the most sensitive and precise comparison between theory and experiment for single donor spin control. It is also shown that there is a significant linear Stark effect for an impurity near the interface, whereas, far from the interface, the quadratic Stark effect dominates. Such precise control of single donor spin states is required particularly in quantum computing applications of single donor electronics, which forms the driving motivation of this work.Comment: 5 pages, 2 figure

A light-cone catalogue from the Millennium-XXL simulation: improved spatial interpolation and colour distributions for the DESI BGS

The use of realistic mock galaxy catalogues is essential in the preparation of large galaxy surveys, in order to test and validate theoretical models and to assess systematics. We present an updated version of the mock catalogue constructed from the Millennium-XXL simulation, which uses a halo occupation distribution method to assign galaxies r-band magnitudes and g − r colours. We have made several modifications to the mock to improve the agreement with measurements from the SDSS and GAMA surveys. We find that cubic interpolation, which was used to build the original halo light cone, produces extreme velocities between snapshots. Using linear interpolation improves the correlation function quadrupole measurements on small scales. We also update the g − r colour distributions so that the observed colours better agree with measurements from GAMA data, particularly for faint galaxies. As an example of the science that can be done with the mock, we investigate how the luminosity function depends on environment and colour, and find good agreement with measurements from the GAMA survey. This full-sky mock catalogue is designed for the ongoing Dark Energy Spectroscopic Instrument Bright Galaxy Survey, and is complete to a magnitude limit r = 20.2

An Overview of Two Incidents Involving African American Fraternities at Indiana University

The current campus climate facing African American Greek fraternal organizations at Indiana University (IU) can be examined through critical incidents of the past. A historical analysis of data sources associated with two incidents involving these organizations at IU provides a better understanding of the challenges students in these organizations may face. This paper aims to provide practitioners with an understanding of how specific policy changes for these fraternities may affect their members, as well as the student body they serve

Origin of the unusually low nitrogen abundances in young populations of the Large Magellanic Cloud

It is a longstanding problem that HII regions and very young stellar populations in the Large Magellanic Cloud (LMC) have the nitrogen abundances ([N/H]) by a factor of ~7 lower than the solar value. We here discuss a new scenario in which the observed unusually low nitrogen abundances can be closely associated with recent collision and subsequent accretion of HI high velocity clouds (HVCs) that surround the Galaxy and have low nitrogen abundances. We show that if the observed low [N/H] is limited to very young stars with ages less than ~10^7 yr, then the collision/accretion rate of the HVCs onto the LMC needs to be ~ 0.2 M_sun/yr (corresponding to the total HVC mass of 10^6-10^7 M_sun) to dilute the original interstellar medium (ISM) before star formation. The required accretion rate means that even if the typical mass of HVCs accreted onto the LMC is ~ 10^7 M_sun, the Galaxy needs to have ~2500 massive HVCs within the LMC's orbital radius with respect to the Galactic center. The required rather large number of massive HVCs drives us to suggest that the HVCs are not likely to efficiently dilute the ISM of the LMC and consequently lower the [N/H]. We thus suggest the transfer of gas with low [N/H] from the Small Magellanic Cloud (SMC) to the LMC as a promising scenario that can explain the observed low [N/H].Comment: 24pages, 6 figures, accepted in Ap

Conditional random slope: A new approach for estimating individual child growth velocity in epidemiological research

Objectives: Conditioning child growth measures on baseline accounts for regression to the mean (RTM). Here, we present the “conditional random slope” (CRS) model, based on a linear-mixed effects model that incorporates a baseline-time interaction term that can accommodate multiple data points for a child while also directly accounting for RTM.Methods: In two birth cohorts, we applied five approaches to estimate child growth velocities from 0 to 12 months to assess the effect of increasing data density (number of measures per child) on the magnitude of RTM of unconditional estimates, and the correlation and concordance between the CRS and four alternative metrics. Further, we demonstrated the differential effect of the choice of velocity metric on the magnitude of the association between infant growth and stunting at 2 years.Results: RTM was minimally attenuated by increasing data density for unconditional growth modeling approaches. CRS and classical conditional models gave nearly identical estimates with two measures per child. Compared to the CRS estimates, unconditional metrics had moderate correlation (r 5 0.65–0.91), but poor agreement in the classification of infants with relatively slow growth (kappa 5 0.38–0.78). Estimates of the velocity-stunting association were the same for CRS and classical conditional models but differed substantially between conditional versus unconditional metrics.Conclusion: The CRS can leverage the flexibility of linear mixed models while addressing RTM in longitudinal analyses