A general relativistic rotating evolutionary universe—Part II

As a sequel to Berman (Astrophys. Space Sci., 2008b), we show that the rotation of the Universe can be dealt by generalised Gaussian metrics, defined in this paper. Robertson-Walker’s metric has been employed with proper-time, in its standard applications; the generalised Gaussian metric implies in the use of a non-constant temporal metric coefficient modifying Robertson-Walker’s standard form. Experimental predictions are made.     

An analysis of carrier phase differential kinematic GPS positioning using DynaPos

A series of activities have been carried out at the University of New Brunswick in an effort to evaluate advances in long-range marine kinematic differential positioning. These activities involved processing and analysis of GPS carrier phase kinematic data sets. Some of the data was collected by UNB and some was provided by The XYZs of GPS Inc. Data were collected using Trimble 5700 and Ashtech Z-12 receivers. The data sets were processed using the software DynaPos provided by the The XYZs of GPS Inc. The best results obtained in our analysis indicate an agreement of 5 cm RMS for the horizontal component and 12 cm RMS for the vertical component between two ionospheric-delay free solutions, in baselines varying from 40 to 100 km.     

Natural entropy production in an inflationary model for a polarized vacuum

Though entropy production is forbidden in standard FRW Cosmology, Berman and Som presented a simple inflationary model where entropy production by bulk viscosity, during standard inflation without ad hoc pressure terms can be accommodated with Robertson–Walker’s metric, so the requirement that the early Universe be anisotropic is not essential in order to have entropy growth during inflationary phase, as we show. Entropy also grows due to shear viscosity, for the anisotropic case. The intrinsically inflationary metric that we propose can be thought of as defining a polarized vacuum, and leads directly to the desired effects without the need of introducing extra pressure terms.     

Lambda-universe in scalar-tensor gravity

We present a lambda-Universe, in scalar-tensor gravity, reviewing Berman and Trevisan’s inflationary case (Berman and Trevisan in Int. J. Theor. Phys., 2009) and then we find a solution for an accelerating power-law scale-factor. The negativity of cosmic pressure implies acceleration of the expansion, even with Λ<0. The cosmological term, and the coupling “constant”, are in fact, time-varying.      

Study of bi-orthogonal modes in magnetic butterflies

We present a bi-orthogonal decomposition of the temporal and latitudinal distribution of solar magnetic fields from synoptic magnetograms. Results are compared with a similar decomposition of the distribution of sunspots since 1874. We show that the butterfly diagrams can be interpreted as the result of approximately constant amplitudes and phases of two oscillations with periods close to 22 years. A clear periodicity of 7 years can also be identified in the most energetic modes of both spatio-temporal series. These results can be used to obtain relevant information concerning the physics of the solar dynamo.     

Laboratory studies on the sputtering contribution to the sodium atmospheres of Mercury and the Moon

To ascertain the importance of sputtering by solar wind ions on the formation of a sodium exosphere around Mercury and the Moon, we have irradiated with 4 keV He ions, the Na bearing tectosilicates: albite, labradorite, and anorthoclase, as well as adsorbed Na layers deposited on albite and on olivine (a neosilicate that does not contain Na). Sodium at the surface and near surface (<40 Å) was quantified with X-ray photoelectron spectroscopy before and after each irradiation to determine the depletion cross section. We measured a cross section for sputtering of Na adsorbed on mineral surfaces, σ_s ≈ 1 × 10^?15 cm² atom^?1. In addition, mass spectrometric analyses of the sputtered flux show that a large fraction of the Na is sputtered as ions rather than as neutral atoms. These results have strong implications for modeling the sodium population within the mercurian and the lunar exospheres.     

Groundwater Level Prediction/Forecasting and Assessment of Uncertainty Using SGS and ARIMA Models: A Case Study in the Bauru Aquifer System (Brazil)

Natural Resources Research - Best water management practices should involve the prediction of the availability of groundwater resources. To predict/forecast and consequently manage these water...     

Triterpenols in mangrove sediments as a proxy for organic matter derived from the red mangrove (Rhizophora mangle)

Mangroves are the dominant type of vegetation along many tropical coasts. Organic matter (OM) derived from mangrove leaf litter and root material is stored in sediments and is a major contributor to the amount and chemical composition of sedimentary OM. A set of organic biomarkers in sediments was applied as a palaeo-indicator for the Holocene dynamics of a mangrove Estuary (Rio Caeté, Pará, Brazil). Six sediment cores were collected perpendicular to the present coast line and analysed for triterpenols and sitosterol. The influence of microbial biomarker degradation was implemented from a previous study. Biomarker profiles were validated with pollen data and multivariate statistics to test whether these compounds were suitable indicators for the palaeo-vegetation. Sediments deposited up to 2 Ma BP showed biomarker assemblages similar to those of recent surface sediment. In two cores, the biomarker composition revealed a transition from marsh to mangrove vegetation. Taraxerol, germanicol and β-amyrin provided the most significant chemotaxonomical information and, especially in combination, served as reliable proxies for OM from Rhizophora mangle in northern Brazil. The maximum age of the mangrove system ranged between 1000 and 5100 yr depending on the topographic elevation of the drilling location.     

Recent effects of tidal and hydro‐meteorological changes on coastal plains near the mouth of the Amazon River

The goal of this work was to understand the main hydrodynamic processes acting on tidal flats of the coast of Amapá near the mouth of the Amazon River, and how they change over the short term (~ 20 years). The analysis of morphological and geobotanical units was carried out by applying processing and interpretation methods to optical and synthetic aperture radar (SAR) images, combined with data on water salinity, maximum flood height, sedimentary facies data, rainfall and river discharge. The temporal analysis of morphological and geobotanical units suggests the relative stabilization of savannah, ‘várzea’ and mangrove areas during the drier period and increasing tidal amplitude between 1987 to 1997. The wetter period and decreasing tidal amplitude between 1997 to 2008 led to an increase in the area of ‘várzea’ and lakes over savannah, and the expansion of mangroves mainly over the inundated field and tidal mud/mixed flats. Therefore, the decrease in rainfall index during the drier period is well‐correlated with the reduction of the Calçoene River discharge and jointly with increasing tidal amplitude favored the increase of migration rate of the mud bank and erosion profile along the littoral. It was followed by the increase of the Calçoene River discharge and jointly with decreasing tidal amplitude during the wetter period, favoring the development of mangroves on muddy substrates near the coastline. Copyright © 2013 John Wiley & Sons, Ltd.