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An Evaluation of the Roll-Rate Stabilization System of the Sidewinder Missile at Mach Numbers from 0.9 to 2.3

Description: A linear stability analysis and flight-test investigation has been performed on a rolleron-type roll-rate stabilization system for a canard-type missile configuration through a Mach number range from 0.9 to 2.3. This type damper provides roll damping by the action of gyro-actuated uncoupled wing-tip ailerons. A dynamic roll instability predicted by the analysis was confirmed by flight testing and was subsequently eliminated by the introduction of control-surface damping about the rolleron hinge line. The control-surface damping was provided by an orifice-type damper contained within the control surface. Steady-state rolling velocities were at all times less than 1 radian per second between the Mach numbers of 0.9 to 2.3 on the configurations tested. No adverse longitudinal effects were experienced in flight because of the tendency of the free-floating rollerons to couple into the pitching motion at the low angles of attack and disturbance levels investigated herein after the introduction of control-surface damping.
Date: April 22, 1955
Creator: Nason, Martin L.; Brown, Clarence A., Jr. & Rock, Rupert S.
Partner: UNT Libraries Government Documents Department

Some characteristics of roll controls having possible application to fin-stabilized ammunition

Description: Report presenting a discussion of the rolling effectiveness of deflected fins, flaps, spoilers, and jet devices that can be used on fin-stabilized ammunition. The possible applications and some of the significant factors affecting the performance of each device are described. The selection of one control over another appears to be mostly designer's choice with some exceptions depending on the roll requirements in a given situation.
Date: March 27, 1957
Creator: Schult, Eugene D.
Partner: UNT Libraries Government Documents Department

Stability of propane-air flames in vortex flow

Description: Report presenting a vortex burner in which the vortex strength could be varied at constant flow rate, which was used for a study of propane-air vortex flames. Results regarding the measurement of vortex strength, turbulence, flames in vortex flow, the fuel-lean vortex flame, and stability of vortex flames are provided.
Date: February 1958
Creator: Potter, A. E., Jr.; Wong, E. L. & Berlad, A. L.
Partner: UNT Libraries Government Documents Department

Flight investigation of a roll-stabilized missile configuration at varying angles of attack at Mach numbers between 0.8 and 1.79

Description: A missile research model was flown at supersonic speed to determine the quality of automatic roll stabilization at varying angles of attack. Aerodynamic rolling and pitching derivatives were determined from the flight record. It was concluded that the combination of the gyro-actuated automatic pilot with wing-tip ailerons provided adequate roll stabilization under conditions encountered in flight.
Date: January 1957
Creator: Zarovsky, Jacob & Gardiner, Robert A.
Partner: UNT Libraries Government Documents Department

Measurement of the Effect of an Axial Magnetic Field on the Reynolds Number of Transition in Mercury Flowing Through a Glass Tube

Description: Note presenting experiments conducted to determine the effect of a strong axial magnetic field on the flow of mercury through a circular channel. The magnetic induction was 15,000 gauss, and the channel was a pyrex tube 17-1/4 inches long and 0.027 inch inside diameter. The results indicated that the stabilizing effect occurred only at Reynolds number above 5,000, so that the region of practical applicability seems to be at fairly high Reynolds numbers and when there are only slight disturbances in the flow.
Date: May 1958
Creator: Bader, Michel & Carlson, William C. A.
Partner: UNT Libraries Government Documents Department

Moduli stabilization in stringy ISS models

Description: We present a stringy realization of the ISS metastable SUSY breaking model with moduli stabilization. The mass moduli of the ISS model is stabilized by gauging of a U(1) symmetry and its D-term potential. The SUSY is broken both by F-terms and D-terms. It is possible to obtain de Sitter vacua with a vanishingly small cosmological constant by an appropriate fine-tuning of flux parameters.
Date: September 28, 2007
Creator: Nakayama, Yu; Nakayama, Yu; Yamazaki, Masahito & Yanagida, T.T.
Partner: UNT Libraries Government Documents Department

Boundary-layer stability diagrams for electrically conducting fluids in the presence of a magnetic field

Description: From Summary: "The effectiveness of a magnetic field in stabilizing the laminar flow of an incompressible, electrically conducting fluid is studied. The neutral stability curves pertaining to a two-dimensional sinusoidal disturbance are presented for flow over a semi-infinite flat plate in the presence of either a coplanar or transverse magnetic field and for channel flow in the presence of a coplanar or transverse magnetic field and for channel flow in the presence of a coplanar magnetic field. As is to be expected, the magnetic field stabilizes the flow unless the velocity profile is distorted by the magnetic field to an inherently unstable shape."
Date: August 1958
Creator: Rossow, Vernon J.
Partner: UNT Libraries Government Documents Department

Neighborhood Price Externalities of Foreclosure Rehabilitation: An Examination of the Neighborhood Stabilization Program

Description: This article examines the neighborhood price impacts of Neighborhood Stabilization Program (NSP) funded foreclosure rehabilitation undertaken by Habitat for Humanity in Dallas County, Texas using a difference-in-difference framework.
Date: January 12, 2017
Creator: Leonard, Tammy; Jha, Nikhil & Zhang, Lei
Partner: UNT College of Arts and Sciences

Analysis of Field Compaction Data: Report 2, Littleville Dam, Westfield River, Massachusetts

Description: Summary: This report is a review of the materials, specifications, procedures, equipment, and testing pertinent to construction and compaction control of the earth-fill embankment of Littleville Dam, Westfield River, Mass., constructed by the U. S. Army Engineer Division, New England.
Date: December 1970
Creator: Torrey, Victor H., III
Partner: UNT Libraries Government Documents Department

A theoretical analysis of the effect of time lag in an automatic stabilization system on the lateral oscillatory stability of an airplane

Description: "A method is presented for determining the effect of time lag in an automatic stabilization system on the lateral oscillatory stability of an airplane. The method is based on an analytical-graphical procedure. The critical time lag of the airplane-autopilot system is readily determined from the frequency-response analysis. The method is applied to a typical present-day airplane equipped with an automatic pilot sensitive to yawing acceleration and geared to the rudder so that rudder control is applied in proportion to the yawing acceleration" (p. 1).
Date: October 28, 1949
Creator: Sternfield, Leonard & Gates, Ordway B., Jr.
Partner: UNT Libraries Government Documents Department

Time histories of horizontal-tail loads, elevator loads, and deformations on a jet-powered bomber airplane during wind-up turns at approximately 15,000 feet and 22,500 feet

Description: Report presenting time histories of horizontal-tail loads, elevator loads, and deformations on a jet-powered bomber airplane at wind-up turns. Results regarding total tail loads, elevator loads and elevator positions, stabilizer and elevator twist, and fuselage deflection are provided.
Date: August 17, 1950
Creator: McGowan, William A.
Partner: UNT Libraries Government Documents Department

Preliminary wind-tunnel investigation of the effect of area suction on the laminar boundary layer over an NACA 64A010 airfoil

Description: Report presenting an investigation in the two-dimensional low-turbulence tunnel on an NACA 64A010 airfoil with permeable surfaces to obtain an indication of the stabilizing effect of area suction on the laminar boundary layer. The surface of the airfoil that was tested had a lot of waves and irregularities, but the theoretically predicted stabilizing effect of area suction on a smooth flat plate was still observed.
Date: April 26, 1948
Creator: Braslow, Albert L.; Visconti, Fioravante & Burrows, Dale L.
Partner: UNT Libraries Government Documents Department

Soil Stabilization and Revegetation at the INEEL Recommendations for Improvement

Description: Soil stabilization for the INEEL Stormwater Pollution Prevention Plan (SWPPP) has mostly been by revegetation, but has experienced only limited success. The purpose of this report is to discuss issues associated with revegetation failures and to explore possible remedies.
Date: March 24, 2003
Creator: Blew, R.D.; Jackson, M.R. & Forman, A.D.
Partner: UNT Libraries Government Documents Department

Sharing the burden of climate change stabilization: An energysector perspective

Description: In this paper we discuss long-term least cost CO2stabilization scenarios based on the SRES AIM A1B scenario in the contextof an international burden-sharing regime. Starting from a stabilizationtarget, regional emission caps are formulated dynamically on the basis ofpast emissions. With these regional caps, the cost-optimal supply fuelmix in the energy sector in the four SRES world regions is calculated,and lower bounds on the volume of traded carbon are estimated. Theallocation scheme provides incentives for early mitigation action. Weestimate additional regional costs incurred by the allocation scheme, andassess the sensitivity of results to changes in the concentrationceiling, discount rates, and start date for burden sharing.
Date: May 1, 2006
Creator: Wagner, Fabian & Sathaye, Jayant
Partner: UNT Libraries Government Documents Department

FY94 and FY95 thermal stabilization campaign report

Description: The report provides a synopsis of the FY94/95 Thermal Stabilization Campaign. The FY94 Thermal Stabilization Campaign ran from November 1, 1994 to June 13, 1995 and stabilized 236 items (22 kg) of reactive plutonium bearing material. A total of 49 cans of stabilized material was moved to the vaults for interim storage. While the initial downtime was high, with an Operating Efficiency (OE) of 27% over the first 3 months, the OE improved to 78% during the last 5 months for an overall DE of 58%. The campaign was completed 85 days ahead of schedule thus exceeding the ``Excellent``date for the Performance Base Incentive (PBI) for this campaign by 25 business days.
Date: January 10, 1996
Creator: Lewis, W.S.
Partner: UNT Libraries Government Documents Department

Economic Recovery: Sustaining U.S. Economic Growth in a Post-Crisis Economy

Description: The 2007-2009 recession was long and deep, and according to several indicators was the most severe economic contraction since the 1930s (but still much less severe than the Great Depression). This report examines the state of the economy in light of the recession.
Date: April 18, 2013
Creator: Elwell, Craig K.
Partner: UNT Libraries Government Documents Department

Why Has the Economy Become Less Volatile?

Description: The 2001 recession was unusually mild and brief by historical standards. At 120 months, the expansion that preceded it had been the longest in U.S. history. Is this a coincidence? A body of research concludes that it is not. This report discusses several theories for what caused this phenomenon.
Date: April 11, 2007
Creator: Labonte, Marc
Partner: UNT Libraries Government Documents Department

Recent Progress in Weakly-Coupled Heterotic String Phenomenology

Description: Some recent developments in the weakly-coupled heterotic string phenomenology are reviewed. We discuss several important issues such as dilaton/moduli stabilization, supersymmetry breaking (by hidden-sector gaugino condensation), gauge coupling unification (or the Newton's constant), the QCD axion, as well as cosmological problems involving the dilaton/moduli and the axion.
Date: July 28, 1997
Creator: Wu, Yi-Yen
Partner: UNT Libraries Government Documents Department