The creep of concrete under load with special reference to the use of Portland-blast furnace cement

From the experiments described the Author concludes that :- (1) Cements, mortars, and concretes yield with time under load. • (2) The rate of creep, greatest in the first two or three months, decreases with time and a final asymptotic or strain equilibrium state is indicated. • (3) Creep is approximately proportional to the applied stress. • (4) Creep increases with the quantity of the mixing water used. • (5) A time or plastic recovery follows the immediate elastic recovery on the release of load the rate of which decreases with time. Plastic recovery is small compared with the creep and equilibrium is reached within the comparatively short period of about 10 days. • (6) Under comparative conditions the creep of Portland -Blast Furnace cement concrete is markedly greater than that of Normal Portland cement concrete. • (7) The creep of Portland -Blast Furnace cement concrete, 1:2:4 mix, 0.55 W/C ratio, tested in air is of the order 1.99 x 10⁻⁶ in. per in. per lb. per sq.in. at the age of one year. • (8) In view of the large creep of Portland -Blast Furnace cement concrete, considerable relief is offered to the steel stress induced by shrinkage

The discrimination of geoforensic trace material from close proximity locations by organic profiling using HPLC and plant wax marker analysis by GC

There is a need to develop a wider empirical research base to expand the scope for utilising the organic fraction of soil in forensic geoscience, and to demonstrate the capability of the analytical techniques used in forensic geoscience to discriminate samples at close proximity locations. The determination of wax markers from soil samples by GC analysis has been used extensively in court and is known to be effective in discriminating samples from different land use types. A new HPLC method for the analysis of the organic fraction of forensic sediment samples has also been shown recently to add value in conjunction with existing inorganic techniques for the discrimination of samples derived from close proximity locations. This study compares the ability of these two organic techniques to discriminate samples derived from close proximity locations and finds the GC technique to provide good discrimination at this scale, providing quantification of known compounds, whilst the HPLC technique offered a shorter and simpler sample preparation method and provided very good discrimination between groups of samples of different provenance in most cases. The use of both data sets together gave further improved accuracy rates in some cases, suggesting that a combined organic approach can provide added benefits in certain case scenarios and crime reconstruction contexts

Entanglement Sharing and Decoherence in the Spin-Bath

The monogamous nature of entanglement has been illustrated by the derivation of entanglement sharing inequalities - bounds on the amount of entanglement that can be shared amongst the various parts of a multipartite system. Motivated by recent studies of decoherence, we demonstrate an interesting manifestation of this phenomena that arises in system-environment models where there exists interactions between the modes or subsystems of the environment. We investigate this phenomena in the spin-bath environment, constructing an entanglement sharing inequality bounding the entanglement between a central spin and the environment in terms of the pairwise entanglement between individual bath spins. The relation of this result to decoherence will be illustrated using simplified system-bath models of decoherence.Comment: 5 pages, 1 figure v2: 6 pages 2 figures, additional example and reference

Radiative Corrections to W^+W^- \to W^+W^- in the Electroweak Standard Model

The cross-section for W^+W^- \to W^+W^- with arbitrarily polarized W bosons is calculated within the Electroweak Standard Model including the complete virtual and soft-photonic O(alpha) corrections. We show the numerical importance of the radiative corrections for the dominating polarized cross-sections and for the unpolarized cross-section. The numerical accuracy of the equivalence theorem is investigated in O(alpha) by comparing the cross-section for purely longitudinal W bosons obtained from the equivalence theorem and from the direct calculation. We point out that the instability of the W boson, which is inherent in the one-loop corrections, prevents a consistent calculation of radiative corrections to the scattering of on-real-mass-shell longitudinal W bosons beyond O(alpha).Comment: 24 pages, LaTeX, uses axodraw, epsfig. Statement clarifie

Integrating diamond with GaN photonic device

The nitrogen vacancy is a photostable emitter in diamond which is optically accessible at room temperature and a potential candidate for quantum information processing as a spin register. The challenge facing research today is the efficient collection and manipulation of the NV’s emissions, such as enhancing the zero phonon line transitions for a coherent spin-photon interface. This project focuses on integrating ultra-thin diamond membranes with established photonic devices. By bonding the diamond to GaN, for example, mode simulations show that light can be coupled significantly into and out of the defect allowing processing across large area PICs

R-Parity Violation and Peccei-Quinn Symmetry in GUTS

We address the question whether it is possible in GUTs to obtain R-parity violation with a large ${\Delta L{/}\Delta B}$ hierarchy of strengths so that the proton is stable while phenomenologically interesting $L$-violation is present. We consider versions of SU(5) with a built-in Peccei-Quinn symmetry spontaneously broken at an intermediate scale. The P-Q symmetry and the field content guarantee a large suppression of the effective $B$-violating terms by a factor $\Lambda^3_{PQ}/M_PM^2_X$ while the effective $L$-violating terms stay large.Comment: 8 pages, no figure

Gluon Fusion: A Probe of Higgs Sector CP Violation

We demonstrate that CP violation in the Higgs sector, \eg\ of a multi-doublet model, can be directly probed using gluon-gluon collisions at the SSC. % requires phyzzx.tex macro packageComment: UCD-93-

R-parity Violation and Semileptonic Decays of B-meson

We investigate the effects of R-parity violation on the semileptonic decays of B-meson in the minimal supersymmetric standard model with explicit R-parity violation and discuss its physical implications. We find that the semileptonic decays of B-meson can be largely affected by the R-parity violation.Comment: 10 pages, LaTex file, no figure. References and a table are added. Tables are improve

Overstory and understory vegetation interact to alter soil community composition and activity

Aim: To test if there is an interactive effect between tree and understory species on the soil microbial community (SMC), community level physiological profiles (CLPP) and soil micro-fauna. Method: A replicate pot experiment with five sapling tree species (Betula pendula, Betula pubescens, Sorbus aucuparia, Quercus petraea and Pinus sylvestris) and a no-tree treatment with and without Calluna vulgaris was established. After 21 months samples were taken for phospholipid fatty acid (PLFA) analysis, CLPP and soil microfauna assessment. Results: There was an interactive effect of tree species and Calluna on the SMC, CLPP and nematode densities. Calluna addition changed the SMC composition (increase in fungal PLFAs) and the CLPP (lower utilisation of most carbon sources but greater utilisation of phenolic acids). A multivariate test for homogeneity of dispersion showed that while Calluna addition resulted in the presence of an altered microbial composition, it did not result in there being less variability among the samples with Calluna than among the samples without Calluna. Sapling trees with Calluna present grew less well than trees without Calluna. Structural equation modelling showed that it is possible that Calluna had an indirect effect on the SMC via below-ground tree biomass as well as a direct effect. Conclusion: Interactions between trees and understory vegetation can impact on the composition of soil biota and their activity