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Relative Yields of Nitrogen-17 Produced by 190-Mev Deuteron Bombardment (open access)

Relative Yields of Nitrogen-17 Produced by 190-Mev Deuteron Bombardment

"Yields of N¹⁷ relative to that produced in LiF have been measured in the 190-Mev deflected deuteron and the 380-Mev alpha beams of the 184-inch synchrocyclotron. The measurements have been performed in all the light elements from 0 through V, with the exception of Sc and the noble gases. In addition, yields were measured in the separated isotopes of Mg...Comparisons are made with other types of yield studies performed with neutrons and protons, and the areas of agreement are noted."
Date: April 13, 1955
Creator: Chupp, Warren William
System: The UNT Digital Library
Searches for Natural Supersymmetry in Hadronic Final States with Heavy Flavor at ATLAS (open access)

Searches for Natural Supersymmetry in Hadronic Final States with Heavy Flavor at ATLAS

None
Date: December 13, 2012
Creator: Butler, Bart Clayton & /SLAC, /Stanford U.
System: The UNT Digital Library
Imaging gene expression in real-time using aptamers (open access)

Imaging gene expression in real-time using aptamers

Signal transduction pathways are usually activated by external stimuli and are transient. The downstream changes such as transcription of the activated genes are also transient. Real-time detection of promoter activity is useful for understanding changes in gene expression, especially during cell differentiation and in development. A simple and reliable method for viewing gene expression in real time is not yet available. Reporter proteins such as fluorescent proteins and luciferase allow for non-invasive detection of the products of gene expression in living cells. However, current reporter systems do not provide for real-time imaging of promoter activity in living cells. This is because of the long time period after transcription required for fluorescent protein synthesis and maturation. We have developed an RNA reporter system for imaging in real-time to detect changes in promoter activity as they occur. The RNA reporter uses strings of RNA aptamers that constitute IMAGEtags (Intracellular MultiAptamer GEnetic tags), which can be expressed from a promoter of choice. The tobramycin, neomycin and PDC RNA aptamers have been utilized for this system and expressed in yeast from the GAL1 promoter. The IMAGEtag RNA kinetics were quantified by RT-qPCR. In yeast precultured in raffinose containing media the GAL1 promoter responded faster …
Date: December 13, 2011
Creator: Shin, Il Chung
System: The UNT Digital Library
The Production of Neutral Hyperons by 5-Bev π$sup -$ Mesons (open access)

The Production of Neutral Hyperons by 5-Bev π$sup -$ Mesons

Neutral hyperons produced by 5-Bev The effects of /sup -/ mesons incident on a large propane bubble chamber are analyzed in detail with respect to production cross sections and angular distributions of production and decays and the A lifetime is measured. The cross section for neutralhyperon (Y/sup 0/) production by the reaction The effects of /sup -/ + p 1100 deg C are Y/sup 0/ + K is 0.98 sintering time 0.16 mb. The cross section for carbon mpacting ( The effects of - + C 1100 deg C are Y/sup 0/ + K) is 6.05 sintering time 0.89 mb. The mean Svlvania Electr decay time is (3.12 sintering time 0.34) x 10/sup -10/ sec. The corrected lifetime is observed to be (3.23 sintering time 0.36) x 10/sup -10/ sec. Although the up-down decay asymmetry for Svlvania Electr hyperons is not significantly different from zero, the fore-aft decay angular distribution is asymmetric; alpha P = -0.31 sintering time 0.12 where the decay proton distribrtion along the Svlvania Electr direction of motion has been examined. This is suggested as evidence for nonconservation of parity in the production interaction. The Svlvania Electr -production angular distribution is peaked backward in the production center …
Date: April 13, 1959
Creator: Hotz, D. F.
System: The UNT Digital Library
Two Topics in Pion Physics. [Part] 1. Photoproduction of Neutral Pions From Complex Nuclei and the Pair-Correlation Function. [Part] 2. The Relative Rate of Absorption of Negative Pions in Hydrogen and Deuterium (open access)

Two Topics in Pion Physics. [Part] 1. Photoproduction of Neutral Pions From Complex Nuclei and the Pair-Correlation Function. [Part] 2. The Relative Rate of Absorption of Negative Pions in Hydrogen and Deuterium

A simple theory of the photoproduction of pi /sup 0/ mesons from complex nuclei based on the impulse and closure approximation is studied. The theory is compared with an experiment of Goodwin, Anderson, and Kenney that shows the dependence of the number of decay gammas from pi /sup 0/ mesons photo- produced from various nuclei as a function of the atomic number at 45, 90, and 135 degrees for incident photon energies from threshold to 350 Mev. The dependence measured near threshold and at 45 degrees does not agree with the simple theory nor is it consistent with partial elastic production. By a method of Placzek and Wick the corrections to the simple theory are estimated, and found to be large near threshold. These corrections may explain the discrepancy between the theory and the experimental results. No information about the nuclear-pair correlation function is obtained. The impulse approximation is used to calculate the relative ratio of the radiative absorption rate of pi /sup -/ mesons absorbed in hydrogen and deuterium from an atomic s state. The calculated value of the ratio T = R( pi /sup -/ + d yields 2n + gamma )/R( pi /sup -/ + p yields …
Date: August 13, 1962
Creator: Traxler, R. H.
System: The UNT Digital Library
Matrix Isolation Studies of High-Temperature Species Group II Chlorides (open access)

Matrix Isolation Studies of High-Temperature Species Group II Chlorides

A matrix isolation technique for the investigation of infrared absorption spectra of molecules of hightemperature species trapped in a pseudo- gas phase'' is described. The spectra of the dichlorides of zinc, cadmium, and mercury in argon, krypton, and xenon matrices are reported. Presence in the gas phase of dimers of zinc chloride and mercuric chloride is noted. An absorption band, previously reported as due to the degenerate bending motion of zinc chloride, is attributed to zinc dimer. (auth)
Date: September 13, 1962
Creator: McNamee, R. W., Jr.
System: The UNT Digital Library
Investigation of the Wett-Ability of Various Pure Metals and Alloys on Beryllium (open access)

Investigation of the Wett-Ability of Various Pure Metals and Alloys on Beryllium

Thesis submitted to University of Tennessee, Knoxville. Activities in a program to determine the wetting behavior of pure metals such as Au, Ag, Ge, Al, and Cu on solid Be are reported. Results of similar investigations of binary alloys such as Be--Ti, Be-Zr, and Be--Pd are also included. The contact angles of the molten metals on Be as a function of temperature, exposure time, and atmosphere were measured. The solid-liquid interfacial reactions occurring as a function of test temperature and atmosphere were investigated, and the liquid- vapor and internal surface tensions for those systems in which interfacial reactions did not appear to occur were calculated. (J.R.D.)
Date: June 13, 1963
Creator: Gilliland, R. G.
System: The UNT Digital Library
Gas atomized precursor alloy powder for oxide dispersion strengthened ferritic stainless steel (open access)

Gas atomized precursor alloy powder for oxide dispersion strengthened ferritic stainless steel

Gas atomization reaction synthesis (GARS) was employed as a simplified method for producing precursor powders for oxide dispersion strengthened (ODS) ferritic stainless steels (e.g., Fe-Cr-Y-(Ti,Hf)-O), departing from the conventional mechanical alloying (MA) process. During GARS processing a reactive atomization gas (i.e., Ar-O{sub 2}) was used to oxidize the powder surfaces during primary break-up and rapid solidification of the molten alloy. This resulted in envelopment of the powders by an ultra-thin (t < 150 nm) metastable Cr-enriched oxide layer that was used as a vehicle for solid-state transport of O into the consolidated microstructure. In an attempt to better understand the kinetics of this GARS reaction, theoretical cooling curves for the atomized droplets were calculated and used to establish an oxidation model for this process. Subsequent elevated temperature heat treatments, which were derived from Rhines pack measurements using an internal oxidation model, were used to promote thermodynamically driven O exchange reactions between trapped films of the initial Cr-enriched surface oxide and internal Y-enriched intermetallic precipitates. This novel microstructural evolution process resulted in the successful formation of nano-metric Y-enriched dispersoids, as confirmed using high energy X-ray diffraction and transmission electron microscopy (TEM), equivalent to conventional ODS alloys from MA powders. The thermal …
Date: December 13, 2011
Creator: Rieken, Joel
System: The UNT Digital Library
A Search for the Rare Decay B^0 \to gamma gamma (open access)

A Search for the Rare Decay B^0 \to gamma gamma

None
Date: June 13, 2013
Creator: Ruland, Andrew Michael & /U. Texas, Austin /SLAC
System: The UNT Digital Library
Observation of the submillimeter cosmic background spectrum (open access)

Observation of the submillimeter cosmic background spectrum

An experimental measurement of the spectrum of the submillimeter cosmic background radiation is described. The experiment consists of measuring the night sky emission at an altitude of 39 km, correcting for the atmospheric molecular line emission, and placing limits on the contamination from sources of continuum radiation such as the apparatus itself and the earth. The observations were made on 24 July 1974 using a fully calibrated liquid-helium-cooled balloon- borne spectrophotometer. Important features of the apparatus include a cooled antenna, a polarizing interferometer, and a germanium bolometric detector. The characterization of the spectrophotometer includes the large angle response and emission of the antenna. The calibration of the instrument and corrections to the observed sky spectrum are based on measurements made during the flight. A simple model of the molecular line emission is used to determine the atmospheric contribution. The resulting spectrum covers the frequency range from 4 to 17 cm$sup -1$ and establishes that the cosmic background radiation follows the high frequency quantum cutoff for a 3K blackbody. A blackbody temperature of 2.99/sub -.$sub 14$/$sup +$.$sup 07$/K is deduced from our data. The present status of the cosmic background observations, which span more than three decades in frequency, is analyzed …
Date: November 13, 1975
Creator: Woody, D.P.
System: The UNT Digital Library
Formation of Be$sup 7$ IN He$sup 3$ Induced Nuclear Reactions. (open access)

Formation of Be$sup 7$ IN He$sup 3$ Induced Nuclear Reactions.

None
Date: August 13, 1964
Creator: Pape, A. J.
System: The UNT Digital Library
High Bandwidth Rotary Fast Tool Servos and a Hybrid Rotary/Linear Electromagnetic Actuator (open access)

High Bandwidth Rotary Fast Tool Servos and a Hybrid Rotary/Linear Electromagnetic Actuator

None
Date: December 13, 2005
Creator: Montesanti, R C
System: The UNT Digital Library
Sum-Frequency Generation from Chiral Media and Interfaces (open access)

Sum-Frequency Generation from Chiral Media and Interfaces

Sum frequency generation (SFG), a second-order nonlinear optical process, is electric-dipole forbidden in systems with inversion symmetry. As a result, it has been used to study chiral media and interfaces, systems intrinsically lacking inversion symmetry. This thesis describes recent progresses in the applications of and new insights into SFG from chiral media and interfaces. SFG from solutions of chiral amino acids is investigated, and a theoretical model explaining the origin and the strength of the chiral signal in electronic-resonance SFG spectroscopy is discussed. An interference scheme that allows us to distinguish enantiomers by measuring both the magnitude and the phase of the chiral SFG response is described, as well as a chiral SFG microscope producing chirality-sensitive images with sub-micron resolution. Exploiting atomic and molecular parity nonconservation, the SFG process is also used to solve the Ozma problems. Sum frequency vibrational spectroscopy is used to obtain the adsorption behavior of leucine molecules at air-water interfaces. With poly(tetrafluoroethylene) as a model system, we extend the application of this surface-sensitive vibrational spectroscopy to fluorine-containing polymers.
Date: February 13, 2006
Creator: Ji, Na
System: The UNT Digital Library
From Radian Waves to Data Streams: Media Environments in DeLillo and Shteyngart (open access)

From Radian Waves to Data Streams: Media Environments in DeLillo and Shteyngart

Undergraduate thesis examining representations of media and technology in two contemporary American novels, "White Noise" by Don DeLillo (1985) and "Super Sad True Love Story" by Gary Shteyngart (2010), with the goal of elucidating the attributes and significance of the technological contexts in fiction as well as contributing to a broader discussion of its operations on consciousness, society, and the cultural imagination.
Date: June 13, 2014
Creator: Young, Michael
System: The UNT Digital Library
National Identity and Anxiety in the Captivity Narratives of Mary Rowlandson and Mary Godfrey (open access)

National Identity and Anxiety in the Captivity Narratives of Mary Rowlandson and Mary Godfrey

Undergraduate thesis expanding exploring the 1836 captivity narrative "An Authentic Narrative of the Seminole War; and the Miraculous Escape of Mrs. Mary Godfrey, and Her Four Female Children." Unlike Mary Rowlandson's "The Sovereignty and Goodness of God," the anonymously-authored "An Authentic Narrative" is almost certainly fabricated. There are no records of a Mrs. Mary Godfrey being captured and redeemed, or even existing at all. However, like Rowlandson's captivity narrative, it attempts to use a woman's experience of captivity to defend and stabilize a national male identity. "An Authentic Narrative" is a variation on the captivity genre that indicates a shift toward the white fraternal national identity described by Dana E. Nelson, even as the female captive's rescue by an escaped slave and the deaths of the white, male rescuers point to the fundamental incoherence of this national identity.
Date: June 13, 2014
Creator: Smith, Caitlin
System: The UNT Digital Library
Layered Double Hydroxides And the Origins of Life on Earth (open access)

Layered Double Hydroxides And the Origins of Life on Earth

Thesis written by a student in the UNT Honors College discussing the origins of life on Earth and how layered double hydroxides were involved.
Date: March 13, 2001
Creator: Brister, Brian
System: The UNT Digital Library
Quantum groups: Geometry and applications (open access)

Quantum groups: Geometry and applications

The main theme of this thesis is a study of the geometry of quantum groups and quantum spaces, with the hope that they will be useful for the construction of quantum field theory with quantum group symmetry. The main tool used is the Faddeev-Reshetikhin-Takhtajan description of quantum groups. A few content-rich examples of quantum complex spaces with quantum group symmetry are treated in details. In chapter 1, the author reviews some of the basic concepts and notions for Hopf algebras and other background materials. In chapter 2, he studies the vector fields of quantum groups. A compact realization of these vector fields as pseudodifferential operators acting on the linear quantum spaces is given. In chapter 3, he describes the quantum sphere as a complex quantum manifold by means of a quantum stereographic projection. A covariant calculus is introduced. An interesting property of this calculus is the existence of a one-form realization of the exterior differential operator. The concept of a braided comodule is introduced and a braided algebra of quantum spheres is constructed. In chapter 4, the author considers the more general higher dimensional quantum complex projective spaces and the quantum Grassman manifolds. Differential calculus, integration and braiding can be …
Date: May 13, 1996
Creator: Chu, C. S.
System: The UNT Digital Library
Measurement of time dependent B{sub d}{sup 0} {bar B}{sub d}{sup 0} mixing parameter using opposite side lepton and D* meson in p{bar p} collisions at {radical}s = 1.8 TeV (open access)

Measurement of time dependent B{sub d}{sup 0} {bar B}{sub d}{sup 0} mixing parameter using opposite side lepton and D* meson in p{bar p} collisions at {radical}s = 1.8 TeV

This thesis presents the results from the investigation of time dependent B{sub d}{sup 0} {bar B}{sub d}{sup 0} mixing in B {yields} lepton X, B{sub d}{sup 0} {yields} D*{sup -} {yields} {bar D}{sup 0} {pi}{sup -}, {bar D}{sup 0} {yields} K{sup +} {pi}{sup -} channel in p{bar p} collisions at {radical}s = 1.8 TeV using 110 pb{sup -1} data collected with the CDF detector at the Fermilab Tevatron Collider. The {bar D}{sup 0} vertex is reconstructed. The B{sub d}{sup 0} decay length is estimated using the distance from the primary vertex to the measured position of the D{sup 0} vertex. The B{sup 0} momentum is estimated using the D{sup 0} momentum and a kinematic correction factor from Monte Carlo. With the dilution floating, {Delta}M{sub d} = 0.55 {+-}{sub 0.16}{sup 0.15} (stat) {+-} 0.06 (syst)ps{sup -1} is measured.
Date: January 13, 1998
Creator: Vandenbrink, S.C.
System: The UNT Digital Library