Alloying of Pd thin films with Nb(001)

Annealing at elevated temperatures (1000–1600 K) of at least 10 ML thick Pd films deposited on Nb(0 0 1) has been found to result in a substrate capped by a pseudomorphic monolayer of Pd. This 1 ML thick Pd cap layer was characterised with a combination of UPS and DFT-calculations. UPS, RHEED and AES show that this cap layer protects the Nb(0 0 1) surface against (oxygen) contamination, which is a well known problem of Nb substrates. AES sputter profiling indicates that a major part of the Pd material in excess of the pseudomorphic monolayer is dissolved in the Nb lattice just below the surface. XPD shows that these dissolved Pd atoms occupy substitutional sites in the substrate. The analysis of the XPS-anisotropy also provides some information about the concentration and positions of the Pd and Nb atoms in the alloyed samples

Updating Bounds on RR-Parity Violating Supersymmetry from Meson Oscillation Data

We update the bounds on $R$-parity violating supersymmetry originating from meson oscillations in the $B^0_{d/s}$ and $K^0$ systems. To this end, we explicitly calculate all corresponding contributions from $R$-parity violating operators at the one-loop level, thereby completing and correcting existing calculations. We apply our results to the derivation of bounds on $R$-parity violating couplings, based on up-to-date experimental measurements. In addition, we consider the possibility of cancellations among flavor-changing contributions of various origins, e.g. from multiple $R$-parity violating couplings or $R$-parity conserving soft terms. Destructive interferences among new-physics contributions could then open phenomenologically allowed regions, for values of the parameters that are naively excluded when the parameters are varied individually.Comment: 53 pages, 10 figures, 2 tables; final versio

Canonical Formulation of pp-waves

We construct a Hamiltonian formulation for the class of plane-fronted gravitational waves with parallel rays (pp-waves). Because of the existence of a light-like Killing vector, the dynamics is effectively reduced to a 2+1 evolution with "time" chosen to be light-like. In spite of the vanishing action this allows us to geometrically identify a symplectic form as well as dynamical Hamiltonian, thus casting the system into canonical form.Comment: To appear in the "Obregon Festschrift

Use of ERTS-1 data in identification, classification, and mapping of salt-affected soils in California

There are no author-identified significant results in this report

Energy Gap from Tunneling and Metallic Sharvin Contacts onto MgB2: Evidence for a Weakened Surface Layer

Point-contact tunnel junctions using a Au tip on sintered MgB2 pellets reveal a sharp superconducting energy gap that is confirmed by subsequent metallic Sharvin contacts made on the same sample. The peak in the tunneling conductance and the Sharvin contact conductance follow the BCS form, but the gap values of 4.3 meV are less than the weak-coupling BCS value of 5.9 meV for the bulk Tc of 39 K. The low value of Delta compared to the BCS value for the bulk Tc is possibly due to chemical reactions at the surface.Comment: 3 pages, 3 figure

BMQ

BMQ: Boston Medical Quarterly was published from 1950-1966 by the Boston University School of Medicine and the Massachusetts Memorial Hospitals. Pages 49-52, v17n2, provided courtesy of Howard Gotlieb Archival Research Center

The effect of dextrose and sucrose sugars upon the properties of ice cream

Publication authorized December 24, 1941.Includes bibliographical references (page 27)

Rapidity Gap Events in Squark Pair Production at the LHC

The exchange of electroweak gauginos in the $t-$ or $u-$channel allows squark pair production at hadron colliders without color exchange between the squarks. This can give rise to events where little or no energy is deposited in the detector between the squark decay products. We discuss the potential for detection of such rapidity gap events at the Large Hadron Collider (LHC). Our numerical analysis is divided into two parts. First, we evaluate in a simplified framework the rapidity gap signal at the parton level. The second part covers an analysis with full event simulation using PYTHIA as well as Herwig++, but without detector simulation. We analyze the transverse energy deposited between the jets from squark decay, as well as the probability of finding a third jet in between the two hardest jets. For the mSUGRA benchmark point SPS1a we find statistically significant evidence for a color singlet exchange contribution. The systematical differences between current versions of PYTHIA and HERWIG++ are larger than the physical effect from color singlet exchange; however, these systematic differences could be reduced by tuning both Monte Carlo generators on normal QCD di--jet data.Comment: 23 pages, 10 figure

The effect of processing on the dispersion of fat in an ice cream mixture

Publication authorized June 26, 1926."This experimental work... was submitted by W. K. Mosley in fulfillment of the thesis requirement for the degree of Master of Arts in the University of Missouri"--P. [3].Digitized 2007 AES.Includes bibliographical references (page 15)