EPS RHA Concrete Bricks – A New Building Material

Reuse of agricultural wastes and industrial by-products for building materials has been gaining popularity in the recent years. Agricultural waste material; namely rice husk ash (RHA), and industrial by-product; namely expanded polystyrene beads (EPS) are discarded in large amounts globally, causing increased environmental problems. Therefore, this paper introduces innovative efforts of the combined use of RHA and EPS wastes for the production of EPS RHA lightweight concrete bricks. Results showed that the commercial development of EPS RHA bricks is not only highly promising but also effectively sequestering the accumulation of these waste materials

Revealing common artifacts due to ferromagnetic inclusions in highly-oriented pyrolytic graphite

We report on an extensive investigation to figure out the origin of room-temperature ferromagnetism that is commonly observed by SQUID magnetometry in highly-oriented pyrolytic graphite (HOPG). Electron backscattering and X-ray microanalysis revealed the presence of micron-size magnetic clusters (predominantly Fe) that are rare and would be difficult to detect without careful search in a scanning electron microscope in the backscattering mode. The clusters pin to crystal boundaries and their quantities match the amplitude of typical ferromagnetic signals. No ferromagnetic response is detected in samples where we could not find such magnetic inclusions. Our experiments show that the frequently reported ferromagnetism in pristine HOPG is most likely to originate from contamination with Fe-rich inclusions introduced presumably during crystal growth.Comment: 8 pages, 7 figure

Galaxy Clustering and Large-Scale Structure from z = 0.2 to z = 0.5 in Two Norris Redshift Surveys

(abridged) We present a study of the nature and evolution of large-scale structure based on two independent redshift surveys of faint field galaxies conducted with the 176-fiber Norris Spectrograph on the Palomar 200-inch telescope. The two surveys together sparsely cover ~20 sq. degrees and contain 835 r < 21 mag galaxies with redshifts 0.2 < z < 0.5. Both surveys have a median redshift of z = 0.30. In order to obtain a rough estimate of the cosmic variance, we analyze the two surveys independently. We measure the comoving correlation length to be 3.70 +/- 0.13 h^-1 Mpc at z = 0.30 with a power-law slope gamma = 1.77 +/- 0.05. Dividing the sample into low (0.2 < z < 0.3) and high (0.32 < z < 0.5) redshift intervals, we see no evidence for a change in the comoving correlation length over the redshift range 0.2 < z < 0.5. Similar to the well-established results in the local universe, we find that intrinsically bright galaxies are more strongly clustered than intrinsically faint galaxies and that galaxies with little ongoing star formation, as judged from the rest-frame equivalent width of the [OII]3727, are more strongly clustered than galaxies with significant ongoing star formation. The rest-frame pairwise velocity dispersion of the sample is 326^+67_-52 km s^-1, ~25% lower than typical values measured locally. The appearance of the galaxy distribution, particularly in the more densely sampled Abell 104 field, is quite striking. The pattern of sheets and voids which has been observed locally continues at least to z ~ 0.5. A friends-of-friends analysis of the galaxy distribution supports the visual impression that > 90% of all galaxies at z < 0.5 are part of larger structures with overdensities of > 5.Comment: 40 pages including 26 Postscript figures; revised version to match version accepted by Ap

General formalism of Hamiltonians for realizing a prescribed evolution of a qubit

We investigate the inverse problem concerning the evolution of a qubit system, specifically we consider how one can establish the Hamiltonians that account for the evolution of a qubit along a prescribed path in the projected Hilbert space. For a given path, there are infinite Hamiltonians which can realize the same evolution. A general form of the Hamiltonians is constructed in which one may select the desired one for implementing a prescribed evolution. This scheme can be generalized to higher dimensional systems.Comment: 6 page

An experimental study of welded bar sleeve wall panel connection under tensile, shear, and flexural loads

This paper presents an experimental study of a new grouted splice connection for wall panels, called Welded Bar Sleeve (WBS). The connections were made from steel pipes and tested with incremental tensile, shear and flexural loads until failure. The aim is to determine the behaviour of the connection under the three load cases. For this, the connections are evaluated in terms of the load–displacement responses, ultimate capacities, ductility responses and some feasibility assessment criteria. WBS was found to provide sufficient strength at the bar embedded length of 8, 8 and 11 times the bar diameter under tensile, shear and flexural loads, respectively. It is effective under tension, but could only service up to 1/3 of its ultimate shear capacity. Flexural load is the most critical load case for the connection. For this, further enhancements are required when subjected to shear and flexural loads

EPS RHA concrete bricks - A new building material

Reuse of agricultural wastes and industrial by-products for building materials has been gaining popularity in the recent years. Agricultural waste material; namely rice husk ash (RHA), and industrial by-product; namely expanded polystyrene beads (EPS) are discarded in large amounts globally, causing increased environmental problems. Therefore, this paper introduces innovative efforts of the combined use of RHA and EPS wastes for the production of EPS RHA lightweight concrete bricks. Results showed that the commercial development of EPS RHA bricks is not only highly promising but also effectively sequestering the accumulation of these waste material

Effective DBHF Method for Asymmetric Nuclear Matter and Finite Nuclei

A new decomposition of the Dirac structure of nucleon self-energies in the Dirac Brueckner-Hartree-Fock (DBHF) approach is adopted to investigate the equation of state for asymmetric nuclear matter. The effective coupling constants of $\sigma$, $\omega$, $\delta$ and $\rho$ mesons with a density dependence in the relativistic mean field approach are deduced by reproducing the nucleon self-energy resulting from the DBHF at each density for symmetric and asymmetric nuclear matter. With these couplings the properties of finite nuclei are investigated. The agreement of charge radii and binding energies of finite nuclei with the experimental data are improved simultaneously in comparison with the projection method. It seems that the properties of finite nuclei are sensitive to the scheme used for the DBHF self-energy extraction. We may conclude that the properties of the asymmetric nuclear matter and finite nuclei could be well described by the new decomposition approach of the G matrix.Comment: 16 pages, 5 figure

Spectrum of Sizes for Perfect Deletion-Correcting Codes

One peculiarity with deletion-correcting codes is that perfect $t$-deletion-correcting codes of the same length over the same alphabet can have different numbers of codewords, because the balls of radius $t$ with respect to the Levenshte\u{\i}n distance may be of different sizes. There is interest, therefore, in determining all possible sizes of a perfect $t$-deletion-correcting code, given the length $n$ and the alphabet size~$q$. In this paper, we determine completely the spectrum of possible sizes for perfect $q$-ary 1-deletion-correcting codes of length three for all $q$, and perfect $q$-ary 2-deletion-correcting codes of length four for almost all $q$, leaving only a small finite number of cases in doubt.Comment: 23 page

The linear spectrum of OSp(32|1) Chern-Simons supergravity in eleven dimensions

We study linearized perturbations of eleven-dimensional $OSp(32|1)$ Chern-Simons supergravity. The action contains a term that changes the value of the cosmological constant, as considered by Horava. It is shown that the spectrum contains a 3-form and a 6-form whose field strengths are dual to each other, thus providing a link with the eleven-dimensional supergravity of Cremmer, Julia and Scherk. The linearized equations for the graviton and Rarita-Schwinger field are shown to be the standard ones as well.Comment: Minor additions. To appear in PRL. 4 pages, twocolumn, Revtex