Physical Sciences and Mathematics Commons^™

Weak Decays Of The H-Dibaryon, Jf Donoghue, E Golowich, Br Holstein

Barry R Holstein

We calculate decay rates and branching fractions for the postulated S=-2 H dibaryon, both for the expected ΔS=1 channels (nΛ,nΣ0,pΣ-) and for the possible ΔS=2 mode (nn). For ΔS=1 decays we find the S waves are dominated by ΔI=(3/2) transitions due to the Pauli principle, which forces the six-quark final state to be in a SU(3) 27-plet. If observed, this would be the first breakdown of the ΔI=1/2 rule. The lifetime is long, of order 10-8 sec, which should be considered in planning experiments. In the ΔS=2 case, we add a consideration of dispersive effects to our previous calculation of …

The Minimum Size Of The Aids Epidemic In The United States, Ron Brookmeyer, Mitchell Gail

Ron Brookmeyer

A new method based on the reported incubation period of transfusion-associated AIDS was used to estimate the number of AIDS cases likely to arise in the USA among those infected before 1986. Between 1986 and 1991 102 000 new cases are projected, with a total cumulative incidence of 135 000 AIDS cases. These estimates do not account for new infections after 1985 nor very long incubation periods and are thus the smallest numbers to be expected. Even if new infections can be effectively prevented, the epidemic will be five times larger than the number of cases observed so far.

University Of London Expedition To Madagascar Report, Nat Quansah

Nat Quansah

No abstract provided.

Gravitational Coupling At Finite Temperature, Jf Donoghue, Br Holstein, Rw Robinett

Barry R Holstein

We discuss a thermodynamic identity which helps explain why ≠ at finite temperature. In addition we complete the discussion of the gravitational force by including the gravitational variation of the temperature. Gradients in the temperature induce extra forces not accounted for by the usual coupling to the energy-momentum tensor.

A Refined Model For The Space-Charge Layer In Composite Electrolyte Systems, Michael Setter

Michael P. Setter

No abstract provided.

Rigid Backbone: A New Geometry For Percolation, Anthony Roy Day, R. R. Tremblay, A.-M. S. Tremblay

Anthony Roy Day

It is shown that the diluted two-dimensional central-force problem belongs to a new class of percolation problems. Geometric properties such as the fractal dimension of the backbone, the correlation-length exponent, and the connectivity are completely different from those of previously studied percolation problems. Explicit calculations of the backbone and the construction of an algorithm which identifies the infinite rigid cluster clearly demonstrate the absence of singly connected bonds, the overwhelming importance of loops, and the long-range nature of the rigidity.

Quantum Monte Carlo Study Of A Lattice Atom Model For Excitonic Fluids, Randall W. Hall, Peter G. Wolynes

Randall W. Hall

G. N. Lewis' Atom And Quantum Monte Carlo Studies Of Liquids, Randall W. Hall, Peter G. Wolynes

Randall W. Hall

Auger Analysis Of Si–H Bonding And Hydrogen Concentration In Hydrogenated Amorphous Silicon, Nancy Burnham, Aj Nelson, Ab Schwartzlander, Se Asher, Ll Kazmerski

Nancy A. Burnham

Auger electron spectroscopy line‐shape analysis of the Si‐L 2 3 V V peak has been performed on hydrogenated amorphous silicon (a‐Si:H). Both a‐Si:H produced by hydrogen implantation of siliconsingle crystals (for analytical standards) and thin films (fabricated for solar cell applications) were examined in these studies. Hydrogen concentrations were confirmed by secondary ion mass spectrometry, and samples having hydrogen content over the range 101 6–102 2 cm− 3 were evaluated. Correlations between the area under the deconvoluted L 2 3 V V transition peak and the known hydrogen content have resulted in a semiquantitative method of determining hydrogen concentration using …

Scanning Auger Microprobe Studies Of Ball Cratered Cds/Cuinse2 Solar Cells, Nancy Burnham, Ll Levenson, Rj Matson, R Noufi, Ll Kazmerski

Nancy A. Burnham

CdS/CuInSe2solar cell films are typically several micrometers thick. Composition profiles of these films are usually carried out on fracture cross sections by scanning Auger microscopy or by recording Auger spectra during ion milling. For fracture cross sections, the depth resolution depends on the electron beam diameter and the roughness of the fracture surface. Ion milling is time consuming, and artifacts are caused by ion beam faceting. Ball cratering requires only a fraction of an hour and provides significant magnification of the film cross section. There is sufficient contrast, both in optical and electron microscopy, to distinguish between CdS and CuInSe2 …

Chiral Symmetry, Nonleptonic Hyperon Decay, And The Feinberg-Kabir-Weinberg Theorem, Jf Donoghue, Br Holstein

Barry R Holstein

We demonstrate that additional (kaon-pole) diagrams must be appended to the traditional commutator-plus-baryon-pole approach to nonleptonic hyperon decay. The modified analysis satisfied the constraints of the Feinberg-Kabir-Weinberg theorem. The new terms are not numerically significant in the case of the usual current-current Hamiltonian, in the continuum limit, but can be important for work using lattice techniques or for other Hamiltonians.

Improvement Of Trace Aluminum Determination By Electrothermal Atomic Absorption Spectrophotometry Using Phosphoric Acid, Chris Craney, Kurt Swartout, F. Smith, C. West

Chris L. Craney

No abstract provided.

Electrochemical Reduction Of Alkyl Halides At Vitreous Carbon Cathodes In Dimethylformamide, James Cleary, Mohammed Mubarak, Kenneth Viera, Mark Anderson, Dennis Peters

Mark R. Anderson

At vitreous carbon electrodes in dimethylformamide which contains tetramethylammonium perchlorate, cyclic voltammograms for 1-iododecane, 1-bromodecane, and 2-bromooctane consist of one irreversible reduction wave signaling formation of the alkyl carbanion, whereas voltammograms for 2-iodooctane, t-butyl bromide, and t-butyl iodide reveal stepwise generation of the alkyl radical and carbanion. Large-scale electrolysis of 1-iododecane at reticulated vitreous carbon yields decane, eicosane, 1-decene, and 1-decanol; the first two compounds arise, respectively, from reaction of decyl carbanions with a proton donor and with unreduced alkyl iodide, whereas the last two species are produced via chemical attack of hydroxide ion on 1-iododecane. Reduction of 1-bromodecane results …

Electrochemistry Of 1,1,4,4-Tetraphenyl-1,3-Butadiene, 1,1,4,4-Tetraphenyl-1,2-Butadiene, And 1,1,4,4-Tetraphenyl-1-Butene In Dimethylformamide, Tsu-Yu Chen, Mark Anderson, Dennis Peters

Mark R. Anderson

In dimethylformamide containing tetra-n-butylammonium perchlorate, 1,1,4,4-tetraphenyl-1-butene exhibits a single polarographic wave; preparative-scale reduction of the starting material produces 1,1,4,4-tetraphenylbutane.A polarogram for 1,1,4,4-tetraphenyl-1,3-butadiene consists of three waves. Large-scale electrolysis of 1,1,4,4-tetraphenyl-1,3-butadiene at potentials corresponding to either the first or second wave yields 1,1,4,4-tetraphenyl-1-butene in the absence of a proton donor and a mixture of 1,1,4,4-tetraphenyl-2-butene and 1,1,4,4-tetraphenyl-1-butene in the presence of excess glacial acetic acid. If 1,1,4,4-tetraphenyl-1,3-butadiene is electrolyzed at a potential on the third polarographic wave, one obtains 1,1,4,4-tetraphenylbutane in the absence of a proton donor but a mixture of 1,1,4,4-tetraphenyl-2-butene and 1,1,4,4-tetraphenylbutane in the presence of glacial acetic acid. …

A Prescription For Computer System Excellence, Robert Yacobellis

Robert H Yacobellis

No abstract provided.

Engineering Product Quality - Current Practices And Future Trends, Robert Yacobellis

Robert H Yacobellis

No abstract provided.

The Rigid Backbone: A New Geometry For Percolation., Anthony Day, R. Tremblay, A.-M. Tremblay

Anthony Roy Day

It is shown that the diluted two-dimensional central-force problem belongs to a new class of percolation problems. Geometric properties such as the fractal dimension of the backbone, the correlation-length exponent, and the connectivity are completely different from those of previously studied percolation problems. Explicit calculations of the backbone and the construction of an algorithm which identifies the infinite rigid cluster clearly demonstrate the absence of singly connected bonds, the overwhelming importance of loops, and the long-range nature of the rigidity.

A Highly Enantioselective Hydrolysis Of -3,5-Diacetoxycyclopent-1-Ene, Donald Deardorff, A. Matthews, D. Mcmeekin, Chris Craney

Chris L. Craney

Exposure of -3,5-diacetoxycyclopent-1-ene () to the hydrolase enzyme acetylcholinesterase (from electric eel) affords In 94% yield 3()-acetoxy-5()-hydroxycyclopent-1-ene () with an e.e. of 96% (greater than 99% e.e. after one recrystallization).

Positive Experiences With Software Metrics, Robert Yacobellis

Robert H Yacobellis

No abstract provided.

Nuclease Activity Of 1,10-Phenanthroline-Copper Ion: Reaction With Cgcgaattcgcg And Its Complexes With Netropsin And Ecori, Thomas Goyne, Michio Kuwabara, Chun Yoon, Theodore Thederahn, David Sigman

Thomas Goyne

No abstract provided.

Electromagnetic And Isopin Breaking Effects Decrease Epsilon'/Epsilon, Jf Donoghue, E Golowich, Br Holstein, J Trampetic

Barry R Holstein

No abstract provided.

Chiral Perturbation-Theory Corrections To Kl-]-Gamma-Gamma, Jf Donoghue, Br Holstein, Ycr Lin

Barry R Holstein

No abstract provided.

A Design Methodology For Software Quality, Robert Yacobellis

Robert H Yacobellis

No abstract provided.

Solution Of Systems With Toeplitz Matrices Generated By Rational Functions, William F. Trench

William F. Trench

No abstract provided.

Extensions Of A Theorem Of Wintner On Systems With Asymptotically Constant Solutions, William F. Trench

William F. Trench

No abstract provided.

Splay Rigidity In The Diluted Central Force Elastic Network, Anthony Roy Day, A.-M. S. Tremblay, R. R. Tremblay

Anthony Roy Day

A Comment on the Letter by Wang and Harris, Phys. Rev. Lett. 55, 2459 (1985).

On The Eigenvalue Problem For A Class Of Band Matrices Including Those With Toeplitz Inverses, William F. Trench

William F. Trench

No abstract provided.

Toward A Theory Of Strict "Claim" Liability: Warranty Relief For Advertising Representations, Wayne Lewis

Wayne Lewis

No abstract provided.