Development of a Rotordynamic Signal Processing MATLAB Interface and a Two-Disk Rotor Model

Using MATLAB and a National Instruments data acquisition card, a signal processing program meant to monitor the behavior of rotordynamic systems in real-time was developed and tested. By using traditional analysis methods in this field of engineering, commonly desired data representations such as bode, polar, orbit, full spectrum plots were able to be produced to a very high accuracy. Additional capabilities offered by this application are slow roll compensation, synchronous and sub-synchronous filtering, and true three dimensional plotting. The verification of this program was done by comparing the results to the ones acquired with Bently Nevada’s “Automated Diagnostics for Rotating Equipment” (ADRE) system. In addition to a data acquisition program, theoretical models of the two-disk rotor were created to estimate the unknown physical parameters of the system. By simulating the rotor with and without gyroscopic effects included, estimates for the stiffness, damping, eccentricity, initial phase, and initial skew values present in the system were determined

ECONOMICALLY OPTIMAL NITROGEN FERTILIZATION FOR YIELD AND PROTEIN IN HARD RED SPRING WHEAT

This analysis determines profit maximizing N fertilization levels of hard red spring wheat (HRSW) for various wheat prices, N prices, and protein-based HRSW price premium/discount (P/D) structures for south eastern Washington data. Fertilizer response data consisting of rates of N fertilization (lb/ac), grain yield (bu/ac), and grain protein (%) were used to statistically estimate regression relationships that predicted yield and protein in response to N. All predicted net return maximizing N, protein, and yield levels were within the data range. Increasing P/D incentives for protein increased optimal N, the expected economic result. At the high P/D structures, the P/D structure dominated N and wheat prices in determining optimal N application levels. Overall, net return-maximizing yields varied only modestly with changes in both N and wheat price in this data set. However, in all scenarios, as P/D incentives increased, net return maximizing N levels were beyond the level that resulted in maximum yield. At the two lowest P/D structures, which provided the lowest reward for protein, it was most profitable to fertilize for slightly less than 14% expected protein. These results indicate that it is not always profitable to use 14% protein as an N fertilization goal. Abbreviations: CT, conventional tillage; HRSW, hard red spring wheat; HRWW, hard red winter wheat; N, nitrogen; NO3, nitrate; NT, No Tillage; P/D, premium/discount; SWSW, soft white spring wheat; SWW, soft white wheat.Crop Production/Industries,

Social Inequity on the Network of Schools of Public Policy, Affairs, and Administration’s Doorsteps: Unpaid Governmental Internships

Social equity is embedded in the public service values of the Network of Schools of Public Policy, Affairs, and Administration (NASPAA). Yet social inequity persists in the facilitation of unpaid governmental internships by some of its accredited programs. This research explores social equity, reviews the service learning pedagogical benefits of internships, explicates the contrasting U.S. legal paradigms permitting unpaid service, and discloses the prevailing pay practice for domestic internships. It then examines the governmental internship paradigm in light of model guidelines. It normatively contends unpaid governmental internships create an access barrier for prospective interns due to their associated socioeconomic opportunity costs. Beyond the normative perspective, using national evidence from paid interns across all majors, research documents (1) more early job offers, (2) more job offers, and (3) higher first position salaries for paid interns. These findings suggest paid governmental interns likely benefit from better outcomes than unpaid interns underscoring the urgency for remedial action from the NASPAA leadership. The article proposes that reconceptualizing governmental internships to a paid only standard yields more good than harm. This pivotal innovation could rectify a long-standing, critical social equity inconsistency within some NASPAA accredited programs. Institutionalizing a paid-only standard is achievable through accreditation modifications and federal reform. Additionally, the proposed national tracking of governmental interns could better inform service-learning pedagogy. Such a data set can spur research regarding paid internships as a pipeline for increasing the representation of the socioeconomically disadvantaged in governmental agencies

Swelling and shrinking kinetics of a lamellar gel phase

We investigate the swelling and shrinking of L_beta lamellar gel phases composed of surfactant and fatty alcohol after contact with aqueous poly(ethylene-glycol) solutions. The height change $\Delta h(t)$ is diffusion-like with a swelling coefficient, S: $\Delta h = S \sqrt{t}$. On increasing polymer concentration we observe sequentially slower swelling, absence of swelling, and finally shrinking of the lamellar phase. This behavior is summarized in a non-equilibrium diagram and the composition dependence of S quantitatively described by a generic model. We find a diffusion coefficient, the only free parameter, consistent with previous measurements.Comment: 3 pages, 4 figures to appear in Applied Physics Letter

Low-Voltage Bandgap Reference Design Utilizing Schottky Diodes

As semiconductor device geometries continue to shrink, the corresponding voltage applied across the processed devices must also be reduced. Therefore reference voltages used in integrated circuits will need to be reduced as well. A typical bandgap reference (BGR) voltage generator uses PN junction diodes or PNP BJT’s to bias the reference. The forward bias voltage of these devices is typically 0.7 volts, and has a limiting effect on how low a reference voltage can be generated, as well as how low a system voltage can be applied. Schottky, or metal-semiconductor (MS), diodes have a lower forward bias voltage, typically of about 0.3 volts. The implementation of Schottky metal-semiconductor diodes in place of PN diodes in the design of the BGR, should allow for lower reference voltage generation. This project consists of the design and simulation of a BGR utilizing MS diodes, followed by fabrication and validation of the design

NASA Hydrogen Peroxide Propellant Hazards Technical Manual

The Fire, Explosion, Compatibility and Safety Hazards of Hydrogen Peroxide NASA technical manual was developed at the NASA Johnson Space Center White Sands Test Facility. NASA Technical Memorandum TM-2004-213151 covers topics concerning high concentration hydrogen peroxide including fire and explosion hazards, material and fluid reactivity, materials selection information, personnel and environmental hazards, physical and chemical properties, analytical spectroscopy, specifications, analytical methods, and material compatibility data. A summary of hydrogen peroxide-related accidents, incidents, dose calls, mishaps and lessons learned is included. The manual draws from art extensive literature base and includes recent applicable regulatory compliance documentation. The manual may be obtained by United States government agencies from NASA Johnson Space Center and used as a reference source for hazards and safe handling of hydrogen peroxide