Detector panels-micrometeoroid impact Patent

Development of large area micrometeoroid impact detector panel

Regge Poles in High-Energy Electron Scattering

The possibility that the photon is described by a Regge trajectory is considered, and the effect of this assumption on the analysis of electron-pion, electron-nucleon, and electron-helium scattering is examined in some detail. Partial-wave projections for the various amplitudes are made in the annihilation channel, and a multiparticle unitarity condition is formally imposed by use of the N/D matrix formulation. Since the photon does not have a fixed spin of one, the spin matrix structure is considerably more complicated than in the conventional theory. The amplitudes are written in terms of the Regge poles corresponding to the photon, ρ-ω meson, etc., and the resulting cross sections are given in the interesting high-energy limit. In contrast to the usual analysis, where form factors depend only on the momentum transfer, we find a larger number of independent functions which depend on the energy as well, however, in a characteristic manner. That is, the essential change due to the Regge behavior of the photon is an over-all nonintegral power of the energy occurring in the cross section. The effect of this factor can be experimentally tested and this possibility is discussed

Zero gravity tissue-culture laboratory

Hardware was developed for performing experiments to detect the effects that zero gravity may have on living human cells. The hardware is composed of a timelapse camera that photographs the activity of cell specimens and an experiment module in which a variety of living-cell experiments can be performed using interchangeable modules. The experiment is scheduled for the first manned Skylab mission

A fundamental solution of a parabolic differential equation of arbitrary even order

Thesis (Ph.D.)--Boston Universit

A polymorphic reconfigurable emulator for parallel simulation

Microprocessor and arithmetic support chip technology was applied to the design of a reconfigurable emulator for real time flight simulation. The system developed consists of master control system to perform all man machine interactions and to configure the hardware to emulate a given aircraft, and numerous slave compute modules (SCM) which comprise the parallel computational units. It is shown that all parts of the state equations can be worked on simultaneously but that the algebraic equations cannot (unless they are slowly varying). Attempts to obtain algorithms that will allow parellel updates are reported. The word length and step size to be used in the SCM's is determined and the architecture of the hardware and software is described

Surface, Bulk, and Rheological Properties of Polyhedral Oligomeric Silsesquioxane/High Density Polyethylene Nanocomposites

In the formulation of high performance nanocomposites, control of miscibility and dispersion of filler material through a polymer matrix is of utmost importance. Due to their inorganic nature most nanofillers are insoluble in polymers, leading to costly/complicated surface modification as a primary means of increasing miscibility and interaction with organic matrices. Polyhedral oligomeric silsesquioxane (POSS) nanostructured chemicals offer an attractive alternative to conventional nanofillers. Due to their hybrid organic-inorganic nature, POSS has the potential to be tailored for miscibility in a wide range of organic matrices not by chemical surface modification but through modification of the molecular structure of the filler itself. The overall goal of this research is to investigate how changes to POSS molecular structure affect miscibility and dispersion in physically blended high density polyethylene (HDPE)/POSS blends. The primary objective of the first section is to understand the effect of POSS cage structure, physical state and R-group alkyl chain length on miscibility and blend performance through a wide range of characterization techniques. Special attention will be paid to rheological, bulk and surface performance of the blends as compared to the neat HDPE matrix. The primary objective of the second section is to determine the utility of theoretical solubility parameter calculations as a means of predicting POSS miscibility in the HDPE matrix. This section will focus on solubility parameters calculated using both group contribution and molecular dynamics simulation methods, determining their proximity to each other, and qualifying their applicability in predicting POSS miscibility and blend performance. This dissertation is comprised of six chapters Chapter I provides an introduction to nanocomposites, as well as background information on HDPE, POSS, pertinent POSS blends and solubility parameter theory. Chapter II gives an overview of the research goals and specific objectives of this research. Chapter III probes the influence of POSS functionality, cage structure and physical state on the bulk properties (thermal, rheological, mechanical) of the melt-processed HDPE/POSS blends. Chapter IV explores HDPE surface modification as a function of POSS incorporation, as well as aggregation and migrational behavior of the POSS molecules. Chapter V surveys POSS theoretical solubility parameter calculations via both group contribution theory and molecular dynamics simulations and correlates these values with observed blend behavior due to incorporation of POSS. Finally, Chapter VI provides recommendations for future work in an attempt to further refine our understanding of the complex behaviors and trends observed in our HDPE/POSS systems

The Impact of Online Homework, Time on Homework, Gender, and Metacognition in Improving Student Achievement in Undergraduate Biology Courses

This study sought to address a gap in the literature to determine whether a relationship exists between use of online homework and student achievement in undergraduate biology courses. Previous studies have examined other STEM courses, but few have considered biology. The purpose of the study was to determine whether homework grades in online homework systems can predict student achievement in introductory undergraduate biology courses. This study utilized a correlational analysis by multiple regression using archival data to determine whether final course grades in undergraduate biology courses can be predicted by grades on online homework, time spent on online homework, gender, or participation in a course on metacognition. A second question considered whether performance on a major assignment in a course on metacognition correlated with biology course grades and found a moderate correlation. The study took place at a small private Christian university in the Southeast, with 311 participants. The study found that there is a significant predictive ability to use these variables in determining course grades. Homework scores were most predictive, but time spent on homework and gender were also significant. Participation in a course on metacognition gave inconclusive results and is one suggestion for further research. Keywords: STEM, online homework, academic achievement, metacognitio