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DEFLECTIONS AND LOAD DISTRIBUTIONS IN LINEAR ELASTIC STRUCTURES--CTAC AND MODE CODES

Description: Since the stress analysis of a complicated statically indeterminate structure involves the handling of many simultaneous equations, the S0207 code for the IBM-650 was developed at Bettis to solve this problem by the use of matrix transformations. The code has two parts, each with a title: (a) the CTAC code gives stresses, deflections, and reactions: and (b) the MODE code calculates natural frequencies and modes of vibration. As an aid to users of the code, a review is given of the elasticity and matrix transformation theory utilized in this code. (auth)
Date: January 1, 1960
Creator: Friedrich, C.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

SO131--AN IBM-650 CODE TO SOLVE PRESSURE AND THERMAL STRESS PROBLEMS IN CORE SUBASSEMBLY PLATES

Description: In the design of nuclear reactor core subassemblies, a stress analysis is often made of a subassembly whose plates differ in geometry, in reactor coolant pressure loading, and in temperature distribution. Bettis code S0131 was developed for the IBM-650 computer to assess the adequacy of the subassembly design and to assist in determining acceptable manufacturing tolerances. The output of the code gives redundant weld reactions, deformations, and stresses in the individual plates. (auth)
Date: August 1, 1959
Creator: Friedrich, C.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

The Wreck of the Hope

Description: Painting depicting the wreck of the Hope.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: 1823
Creator: Caspar David Friedrich
Item Type: Refine your search to only Artwork
Partner: UNT College of Visual Arts + Design

Altes Museum

Description: Total facade with colonnade
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: 1816/1818
Creator: SCHINKEL, Karl Friedrich
Item Type: Refine your search to only Artwork
Location Info:
Partner: UNT College of Visual Arts + Design

Railguns and plasma accelerators: arc armatures, pulse power sources and US patents

Description: Railguns and plasma accelerators have the potential for use in many basic and applied research projects, such as in creating high-pressures for equation-of-state studies and in impact fusion. A brief review of railguns and plasma accelerators with references is presented. Railgun performance is critically dependent on armature operation. Plasma arc railgun armatures are addressed. Pulsed power supplies for multi-stage railguns are considered. This includes brief comments on the compensated pulsed alternator, or compulsator, rotating machinery, and distributed energy sources for railguns. References are given at the end of each section. Appendix A contains a brief review of the US Patents on multi-staging techniques for electromagnetic accelerators, plasma propulsion devices, and electric guns.
Date: November 1, 1980
Creator: Friedrich, O.M. Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

A Germanium Detector with Optimized Compton Veto for High Sensitivity at Low Energy

Description: We have built a prototype germanium detector with a Compton veto that is optimized for high sensitivity in the low-energy range around {approx}100 keV. It is specifically designed to address the problem to directly detect plutonium gamma emissions in spent nuclear fuel by non-destructive assay. This is not possible with current detectors due to the large low-energy background of Compton-scattered high-energy radiation from the fission products, whose gamma flux is at least 6 to 7 orders of magnitude higher than the Pu signal. Our instrument is designed to assess the feasibility to selectively suppress the background in the low-energy region around {approx}100 keV with the strongest Pu X-ray and gamma emissions lines. It employs a thin Ge detector with a large Compton veto directly behind it to suppress the background from forward-scattered radiation by anti-coincidence vetoing. This report summarizes the design considerations and the performance of the instrument.
Date: November 30, 2011
Creator: Friedrich, S
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Monk by the Sea

Description: Painting depicting a monk by the sea.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: 1809
Creator: Caspar David Friedrich
Item Type: Refine your search to only Artwork
Partner: UNT College of Visual Arts + Design

Biological Applications of Cryogenic Detectors

Description: High energy resolution and broadband efficiency are enabling the use of cryogenic detectors in biological research. Two areas where they have found initial application are X-ray absorption spectroscopy (XAS) and time-of-flight mass spectrometry (TOF-MS). In synchrotron-based fluorescence-detected XAS cryogenic detectors are used to examine the role of metals in biological systems by measuring their oxidation states and ligand symmetries. In time-of-flight mass spectrometry cryogenic detectors increase the sensitivity for biomolecule detection and identification for masses above {approx}50 kDa, and thus enable TOF-MS on large protein complexes or even entire viruses. More recently, cryogenic detectors have been proposed as optical sensors for fluorescence signals from biomarkers. We discuss the potential for cryogenic detectors in biological research, as well as the challenges the technology faces.
Date: December 3, 2003
Creator: Friedrich, S
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

SEAL-SHELL-2--A COMPUTER PROGRAM FOR THE STRESS ANALYSIS OF A THICK SHELL OF REVOLUTION WITH AXISYMMETRIC PRESSURES, TEMPERATURES, AND DISTRIBUTED LOADS

Description: The ALTAC-3 computer program SEAL-SHELL-2, which determines stresses and deflections in thick or thin shells of revolution, is described. The shells are linear-elastic with bending, shear, and tensile strains. Pressures, temperatures, and distributed loads are axisymmetric. The theory for the program, in FORTRAN II for a 32,000-word computer, is presented. Sample problems are also included. (auth)
Date: December 1, 1963
Creator: Friedrich, C.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

SEAL-SHELL-A DIGITAL PROGRAM TO DETERMINE STRESSES AND DEFLECTIONS IN AN AXISYMMETRIC SHELL OF REVOLUTION

Description: SEAL-SRELL, a FORTRAN II program registered as code number M0077 at Bettis Atomic Power Laboratory, is written for the Philco 2000 computer with two tape units. The program is designed to determine loads, deflections, and stresses in a thin shell of revolution under axisymmetric end loads and pressure. (auth)
Date: September 1, 1961
Creator: Friedrich, C.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Quantifying the Sensitivity of Superconducting High-Resolution X-Ray Spectrometers

Description: Superconducting tunnel junction (STJ) X-ray spectrometers have been developed for synchrotron-based high-resolution soft X-ray spectroscopy. We are quantifying the improvements in sensitivity that STJ spectrometers can offer for the analysis of dilute specimens over conventional semiconductor and grating spectrometers. We present analytical equations to quantify the improvements in terms of spectrometer resolution, detection efficiency and count rate capabilities as a function of line separation and spectral background. We discuss the implications of this analysis for L-edge spectroscopy of first-row transition metals.
Date: October 4, 2004
Creator: Drury, O & Friedrich, S
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

Promising X-ray fluorescence tests for superconducting tunneljunction detector

Description: Scientists in the Physical Biosciences Division of the Ernest Orlando Berkeley National Laboratory (Berkeley Lab) studying transition metals in proteins with fluorescence-detected L-edge absorption spectroscopy have found the measurements to be extremely challenging. The difficulty is that the metal centers are present in very dilute concentrations so that their weak fluorescence is often obscured by strong background signals carbon and oxygen. To solve this problem, the Berkeley group has been working with researchers from the Advanced Detector Group at the Lawrence Livermore National Laboratory on an energy-dispersive superconducting tunnel junction x-ray detector. These devices in principle have the energy resolution needed to reveal the metal signal. The most recent results with the latest version of the detector on Beamline 4.0.1-2 at the Advanced Light Source (ALS) illustrate the promise of the cryogenic detector strategy not only for this application but also for spectroscopy of other types of dilute samples. Transition-metal complexes are key elements in many biologically important processes that are catalyzed by proteins (enzymes), photosynthesis being a prime example. The changes in that occur in electronic structure throughout a catalytic cycle are the subject of much research aimed at understanding the mechanisms of these processes. L-edge x-ray spectroscopy offers several advantages relative to the more common K-edge techniques, since it involves allowed transitions to the d-orbitals associated with metal-ligand bonding. It also has a rich multiplet structure interpretable by theory and higher spectral resolution.
Date: May 15, 2001
Creator: Friedrich, Stephan & Robinson, Arthur L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

The Small Wind Tunnel of the DVL

Description: A general description of the small DVL wind tunnel is provided, with emphasis on air conduction, blower and velocity regulation, velocity measurement, and balance and model suspension.
Date: January 1934
Creator: Seewald, Friedrich
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Law of Similitude for the Surface Resistance of Lacquered Planes Moving in a Straight Line Through Water

Description: The proof of the validity of the Reynolds law of similitude for the surface resistance of planes has been developed with an accuracy hitherto unattained and for a large range of lengths and speeds. It has been shown that, in addition to the form resistance, the resistance of the longitudinal edges must be taken into account.
Date: April 1925
Creator: Gebers, Friedrich
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Determination of Stresses and Deformations of Aircraft Propellers

Description: A method is described for testing the strength of propellers of any shape. It is shown that the shape of the propeller greatly affects the stresses, and that great caution must be exercised if the relieving effect of the centrifugal force, which exists in every propeller with a straight blade axis, is to be increased by curving the blade axis. In a numerical example, the calculation is made for a certain revolution speed at which the actual distortion is then measured. The results of the calculation agree satisfactorily with the experimental results.
Date: May 1932
Creator: Seewald, Friedrich
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Flutter in Propeller Blades

Description: This report considers two different explanations for propeller breaks caused by propeller flutter. The two possibilities are combined vibrations of the blade, similar to those of the wings, which develop by absorbing energy from the air stream and converting it into vibrations without the aid of any periodic external disturbance. The other possibility examined is forced vibrations, which are produced in every structure by periodically variable impulses. Such vibrations are especially dangerous when the disturbing impulses which cause them have a frequency equal to the natural frequency of the system.
Date: October 1931
Creator: Seewald, Friedrich
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

On Floats and Float Tests

Description: The principal source of information on float resistance is the model test. In view of the insuperable difficulties opposing any attempt at theoretical treatment of the resistance problem, particularly at attitudes which tend toward satisfactory take-off, such as the transitory stage to planing, the towing test is and will remain the primary method for some time.
Date: September 1931
Creator: Seewald, Friedrich
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Rigid Airships

Description: Memorandum presenting the history and development of airships. Tables containing information and statistics regarding some of the current airships are provided.
Date: November 1923
Creator: Stahl, Friedrich
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

Ultrahigh Energy Resolution Gamma-ray Spectrometers for Precision Measurements of Uranium Enrichment

Description: Superconducting Gamma-ray detectors offer an order of magnitude higher energy resolution than conventional high-purity germanium detectors. This can significantly increase the precision of non-destructive isotope analysis for nuclear samples where line overlap affects the errors of the measurement. We have developed Gamma-detectors based on superconducting molybdenum-copper sensors and bulk tin absorbers for nuclear science and national security applications. They have, depending on design, an energy resolution between {approx}50 and {approx}150 eV FWHM at {approx}100 keV. Here we apply this detector technology to the measurement of uranium isotope ratios, and discuss the trade-offs between energy resolution and quantum efficiency involved in detector design.
Date: June 9, 2006
Creator: Ali, S; Hau, I D; Niedermayr, T R & Friedrich, S
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department

A Compton-Vetoed Germanium Detector with Increased Sensitivity at Low Energies

Description: The difficulty to directly detect plutonium in spent nuclear fuel due to the high Compton background of the fission products motivates the design of a Gamma detector with improved sensitivity at low energies. We have built such a detector by operating a thin high-purity Ge detector with a large scintillator Compton veto directly behind it. The Ge detector is thin to absorb just the low-energy Pu radiation of interest while minimizing Compton scattering of high energy radiation from the fission products. The subsequent scintillator is large so that forward scattered photons from the Ge detector interact in it at least once to provide an anti-coincidence veto for the Ge detector. For highest sensitivity, additional material in the line-of-sight is minimized, the radioactive sample is kept thin, and its radiation is collimated. We will discuss the instrument design, and demonstrate the feasibility of the approach with a prototype that employs two large CsI scintillator vetoes. Initial spectra of a thin Cs-137 calibration source show a background suppression of a factor of {approx}2.5 at {approx}100 keV, limited by an unexpectedly thick 4 mm dead layer in the Ge detector.
Date: March 29, 2012
Creator: Friedrich, S; Bates, C; Drury, O B; Burks, M & DiPrete, D
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department