The Characteristics of Some Permafrost Soils in the Mackenzie Valley, N.W.T.

Describes in detail soil profiles examined in dug pits at three ecologically distinct localities in the vicinity of Reindeer Depot, Inuvik and Norman Wells: tundra, tundra-boreal forest transition, and boreal forest. Samples were air dried, ground, sieved and analyzed. The climate, vegetation, surficial geology and permafrost conditions at each site are indicated. Descriptions are given of eight soil profiles, and the chemical, mechanical and mineralogical characteristics are separately tabulated. Each profile is referred to both the Canadian and the USDA 1960 7th approximation systems of classification

Quantum dot emission from site-controlled ngan/gan micropyramid arrays

InxGa1−xN quantum dots have been fabricated by the selective growth of GaN micropyramid arrays topped with InGaN/GaN quantum wells. The spatially, spectrally, and time-resolved emission properties of these structures were measured using cathodoluminescence hyperspectral imaging and low-temperature microphotoluminescence spectroscopy. The presence of InGaN quantum dots was confirmed directly by the observation of sharp peaks in the emission spectrum at the pyramid apices. These luminescence peaks exhibit decay lifetimes of approximately 0.5 ns, with linewidths down to 650 me

Anomalous acoustic reflection on a sliding interface or a shear band

We study the reflection of an acoustic plane wave from a steadily sliding planar interface with velocity strengthening friction or a shear band in a confined granular medium. The corresponding acoustic impedance is utterly different from that of the static interface. In particular, the system being open, the energy of an in-plane polarized wave is no longer conserved, the work of the external pulling force being partitioned between frictional dissipation and gain (of either sign) of coherent acoustic energy. Large values of the friction coefficient favor energy gain, while velocity strengthening tends to suppress it. An interface with infinite elastic contrast (one rigid medium) and V-independent (Coulomb) friction exhibits spontaneous acoustic emission, as already shown by M. Nosonovsky and G.G. Adams (Int. J. Ing. Sci., {\bf 39}, 1257 (2001)). But this pathology is cured by any finite elastic contrast, or by a moderately large V-strengthening of friction. We show that (i) positive gain should be observable for rough-on-flat multicontact interfaces (ii) a sliding shear band in a granular medium should give rise to sizeable reflection, which opens a promising possibility for the detection of shear localization.Comment: 13 pages, 10 figure

Surface Enhanced Raman Spectroscopy(SERS) of TMPyP on Ag Nanoparticles.

This work was aimed to study the role of interaction between silver nanoparticles, TMPyP and Graphen Oxide(GO) on surface enhanced Raman scattering (SERS) signals. Silver nanoparticles(AgNPs) prepared by chemical reduction of AgNO3. SERS substrates show remarkable difference in spectral features due to the different enhancement contributions from the local chemical groups. Closely spaced NPs result in the enhancement of electromagnetic coupling between NPs leading to strong confinement of local electric field leading to large SERS enhancement. Graphene Oxide/TMPyP interaction nanostructures forming a composite with strong interaction, this came with identical results obtained in NanoPhotonics Research Group in UCD1. Depending on the quantum mechanics, this indicates match the energy levels between the reactants and increase the free electrons in the outer shells which enhances the surface plasmons signal

Studying of Surface Enhanced Raman Scattering (SERS) spectrum of Ag nano thinfilm with Rhodamine6G and Graphen oxide.

Ag nano thinfilm with thickness 10 nm prepared on the clean coverslips glass, was done by using deposition vacuum system and the surface morphology done by atomic force microscopy (AFM). Nd-YAG (532 nm) green laser and a 50x objective was used as a excitation source. Composites of Rh6G, GO and silver nano thinfilm showed a good substrate for SERS signals. Strong SERS signals indicating match the energy levels of materials interacting with each other and increase the free electrons in external shells, depending on the quantum mechanics

Orbit spaces of free involutions on the product of two projective spaces

Let $X$ be a finitistic space having the mod 2 cohomology algebra of the product of two projective spaces. We study free involutions on $X$ and determine the possible mod 2 cohomology algebra of orbit space of any free involution, using the Leray spectral sequence associated to the Borel fibration $X \hookrightarrow X_{\mathbb{Z}_2} \longrightarrow B_{\mathbb{Z}_2}$. We also give an application of our result to show that if $X$ has the mod 2 cohomology algebra of the product of two real projective spaces (respectively complex projective spaces), then there does not exist any $\mathbb{Z}_2$-equivariant map from $\mathbb{S}^k \to X$ for $k \geq 2$ (respectively $k \geq 3$), where $\mathbb{S}^k$ is equipped with the antipodal involution.Comment: 14 pages, to appear in Results in Mathematic

Bi-Objective Community Detection (BOCD) in Networks using Genetic Algorithm

A lot of research effort has been put into community detection from all corners of academic interest such as physics, mathematics and computer science. In this paper I have proposed a Bi-Objective Genetic Algorithm for community detection which maximizes modularity and community score. Then the results obtained for both benchmark and real life data sets are compared with other algorithms using the modularity and MNI performance metrics. The results show that the BOCD algorithm is capable of successfully detecting community structure in both real life and synthetic datasets, as well as improving upon the performance of previous techniques.Comment: 11 pages, 3 Figures, 3 Tables. arXiv admin note: substantial text overlap with arXiv:0906.061

The Blackbody Radiation Spectrum Follows from Zero-Point Radiation and the Structure of Relativistic Spacetime in Classical Physics

The analysis of this article is entirely within classical physics. Any attempt to describe nature within classical physics requires the presence of Lorentz-invariant classical electromagnetic zero-point radiation so as to account for the Casimir forces between parallel conducting plates at low temperatures. Furthermore, conformal symmetry carries solutions of Maxwell's equations into solutions. In an inertial frame, conformal symmetry leaves zero-point radiation invariant and does not connect it to non-zero-temperature; time-dilating conformal transformations carry the Lorentz-invariant zero-point radiation spectrum into zero-point radiation and carry the thermal radiation spectrum at non-zero temperature into thermal radiation at a different non-zero-temperature. However, in a non-inertial frame, a time-dilating conformal transformation carries classical zero-point radiation into thermal radiation at a finite non-zero-temperature. By taking the no-acceleration limit, one can obtain the Planck radiation spectrum for blackbody radiation in an inertial frame from the thermal radiation spectrum in an accelerating frame. Here this connection between zero-point radiation and thermal radiation is illustrated for a scalar radiation field in a Rindler frame undergoing relativistic uniform proper acceleration through flat spacetime in two spacetime dimensions. The analysis indicates that the Planck radiation spectrum for thermal radiation follows from zero-point radiation and the structure of relativistic spacetime in classical physics.Comment: 21 page