Phase 2 study of improved materials for use on Scout rocket motor nozzles

Nozzle material performance data were obtained, and the feasibility was determined of using new materials on the Scout rocket motor nozzles. Stress and heat transfer analyses were conducted to aid in the selection of optimum materials for nozzle tests. A reimpregnated and graphitized throat insert was fabricated along with two nozzles with ablative throats. The dissection and determining of char and erosion of two nozzles fired on X-259 loaded cases are discussed; one of the nozzles used a graphite phenolic ablative throat insert, and the other unit was a standard X-259 nozzle with a reduced area ATJ graphite throat insert

ACTS propagation terminal prototype planning and design

The planning and design of a prototype propagation receiving terminal for beacon signals at 27 and 20 GHz bands are examined. The developmental plan is discussed, followed by technical design considerations including, the Advanced Communications Technology Satellite (ACTS) system salient features and frequency plan, beacon signal parameters and specifications, system calculations, and terminal hardware design issues

Feasibility study of a synthesis procedure for array feeds to improve radiation performance of large distorted reflector antennas

The topics covered include the following: (1) performance analysis of the Gregorian tri-reflector; (2) design and performance of the type 6 reflector antenna; (3) a new spherical main reflector system design; (4) optimization of reflector configurations using physical optics; (5) radiometric array design; and (7) beam efficiency studies

A depolarization and attenuation experiment using the COMSTAR and CTS satellites

Monthly statistical data are presented on ground rainfall rate and attenuation of satellite downlinks at 11.7 GHz, 19.04 GHz, and 28.56 GHz and on cross-polarization isolation at 11.7 GHz. Regression equations for relating isolation to attenuation, attenuation to rain rate, and attenuation at one frequency to attenuation at another frequency are also included. Longer-term statistics are also presented and discussed

Multi-Dimensional Clustering of Roles in the NBA

While in the National Basketball Association (NBA), players are often described by the position that they play and not necessarily the role that they fill on the team. In this thesis, newly defined player roles have been identified by applying multi-dimensional clustering techniques on thirty-eight variables for over ten thousand player samples. These roles help to differentiate players that play the same traditional position, and will allow for new comparisons between players to be produced. Using player statistics from nineteen seasons, models were developed using three separate clustering techniques: Gaussian Mixtures, Density-Based Spatial Clustering of Applications with Noise (DBSCAN), and k-Means. After the models were developed a final model was chosen that provided the best clusters that were used to identify the new roles. These new roles are able to be used to identify replacements for certain players, signing a player that fulfills the same role, or by drawing comparisons between new players in the NBA and the historical roles that other players have fulfilled

β-Alanine Supplementation Has No Effect on Rowing Performance in College Age Athletes

Please view abstract in the attached PDF file

The Importance of Immunizations in School-Aged Children

This paper identifies in detail the importance of vaccinations, focusing primarily on the category of school-aged children. All 12 vaccines are discussed individually, recognizing the disease/diseases they are protecting against, benefits of the vaccine, how and to whom the vaccine is administered, contraindications for the immunization, and risks associated with each vaccination. The information used in this project is from a combination of scholarly peer-reviewed journal articles, medical texts, and information from the Centers for Disease Control and Prevention (CDC). It addresses all regulated childhood vaccinations including hepatitis B (Hep B); haemophilus influenzae type b (Hib); diphtheria, tetanus, and pertussis (DTaP/Tdap); inactivated polio vaccine (IPV); pneumococcal conjugate vaccine (PCV13); rotavirus; measles, mumps, and rubella (MMR); varicella; hepatitis A (Hep A); meningococcal (MenACWY); influenza (Flu); and the human papillomavirus vaccine (HPV)

Strange Quark Contributions to Parity-Violating Asymmetries in the Backward Angle G0 Electron Scattering Experiment

We have measured parity-violating asymmetries in elastic electron-proton and quasi-elastic electron-deuteron scattering at Q^2 = 0.22 and 0.63 GeV^2. They are sensitive to strange quark contributions to currents in the nucleon, and to the nucleon axial current. The results indicate strange quark contributions of < 10% of the charge and magnetic nucleon form factors at these four-momentum transfers. We also present the first measurement of anapole moment effects in the axial current at these four-momentum transfers.Comment: 5 pages, 2 figures, changed references, typo, and conten

Transverse Beam Spin Asymmetries at Backward Angles in Elastic Electron-Proton and Quasi-elastic Electron-Deuteron Scattering

We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasi-elastic scattering on the deuteron, at backward angles (lab scattering angle of 108 degrees) for Q2 = 0.22 GeV^2/c^2 and 0.63 GeV^2/c^2 at beam energies of 362 MeV and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (piN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasi-static deuterium approximation, and is also in agreement with theory

Transverse Beam Spin Asymmetries in Forward-Angle Elastic Electron-Proton Scattering

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely-polarized 3 GeV electrons from unpolarized protons at Q^2 = 0.15, 0.25 (GeV/c)^2. The results are inconsistent with calculations solely using the elastic nucleon intermediate state, and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A_n provides a direct probe of the imaginary component of the 2-gamma exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.Comment: 5 pages, 3 figures, submitted to Physical Review Letters; shortened to meet PRL length limit, clarified some text after referee's comment