International Journal of Geology


ISSN: 1998-4499
Volume 11, 2017

Notice: As of 2014 and for the forthcoming years, the publication frequency/periodicity of NAUN Journals is adapted to the 'continuously updated' model. What this means is that instead of being separated into issues, new papers will be added on a continuous basis, allowing a more regular flow and shorter publication times. The papers will appear in reverse order, therefore the most recent one will be on top.

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Volume 11, 2017


Title of the Paper: Remote Sensing and 210PB Geochronology in Sediment Profiles of the Mãe d’Água Dam for Evaluation of Areas Impacted by Urbanization

 

Authors: Fernandes F. A., Isidoro J. M. G. P. B., Fiebig M. C., Poleto C. D.

Pages: 35-41

Abstract: A primary outcome of water basin urbanization is the set of changes of the natural environment into an anthropic environment, favoring the formation of residential and industrial conglomerates. Such changes lead to increases in water demand, causing higher production and release of effluents from anthropic actions, in addition to originating diffuse sources of pollution. These changes can drastically deteriorate the physicochemical characteristics of the local water resources. Due to the absence of urban planning during the last forty years, the water basin of the Mãe d’Água dam has brought to the top some environmental liabilities, such as organic and/or inorganic contaminants. In this context, the present study sought to evaluate the isotopic composition using lead 210 (210Pb) in the different sedimentary layers produced in the water basin that composes the Mãe d’Água dam. With this, it is possible to characterize and identify the urbanization process on the water basin, applying the geochronology technique. Samples were collected in June 2014, where two sediment samplings were taken both at the entrance and near the lake margin of the dam (T1 coordinates: 488716.3334; 6672912.682, and T4 coordinates: 488729.6452; 6672984.7221). A "Piston core" sediment sampler was used to extract the samples. The geochronology studies (210Pb), that date the years in which sediment deposition occurred, allowed to make an outlook of the evolutionary process of environmental degradation that the basin has been suffering from over the last four decades. This was achieved by means of multiple remote sensing devices that allowed confronting and displaying the evolution of urbanization in the studied water basin. Thus, identification of the layer’s deposition period, by combining techniques such as 210Pb geochronology and remote sensing, enables to find possible causes of sediment contribution to the reservoir , such as urban expansion, industrialization, erosion, agricultural practices. Therefore, the present study describes the impacts caused by urbanization on the Mãe d’Água water basin.


Title of the Paper: Spatial and Temporal Pattern of Global Seismicity Extracted by Dimensionality Reduction

 

Authors: Akihisa Okada, Mitsuhiro Toriumi, Yoshiyuki Kaneda

Pages: 26-34

Abstract: Constructing a predictive model of earthquake activity is difficult due to the complexity of mechanisms and variety of components. We do not know even what effective features are involved in seismic processes. Thus, we adopted a statistical approach for extracting features of global seismicity. We extracted the features from an open earthquake data catalog by using principal component analysis to reveal the spatial linkages and time dependence of earthquake activity. For principal component analysis, we defined earthquake occurrence rate and regarded its time series as samples and regional labels as the dimensionality. We demonstrate that this method accurately identifies past earthquake activity and reveals correlations among remote locations and time dependence of seismicity features. We also discussed the normality of the sample distribution to confirm the validity of the principal component analysis. These results will help the construction of a predictive earthquake activity model.


Title of the Paper: Geoexchanger System for Buildings Heating and Cooling

 

Authors: Abdeen Mustafa Omer

Pages: 8-25

Abstract: Geothermal heat pumps (GSHPs), or direct expansion (DX) ground source heat pumps, are a highly efficient renewable energy technology, which uses the earth, groundwater or surface water as a heat source when operating in heating mode or as a heat sink when operating in a cooling mode. It is receiving increasing interest because of its potential to decrease primary energy consumption and thus reduce emissions of the greenhouse gases (GHGs). The main concept of this technology is that it uses the lower temperature of the ground (approximately <32°C), which remains relatively stable throughout the year, to provide space heating, cooling and domestic hot water inside the building area. The main goal of this study was to stimulate the uptake of the GSHPs. Recent attempts to stimulate alternative energy sources for heating and cooling of buildings have emphasised the utilisation of the ambient energy from ground source and other renewable energy sources. The purpose of this study, however, was to examine the means of reducing of energy consumption in buildings, identifying GSHPs as an environmental friendly technology able to provide efficient utilisation of energy in the buildings sector, promoting the use of GSHPs applications as an optimum means of heating and cooling, and presenting typical applications and recent advances of the DX GSHPs. The study highlighted the potential energy saving that could be achieved through the use of ground energy sources. It also focused on the optimisation and improvement of the operation conditions of the heat cycle and performance of the DX GSHP. It is concluded that the direct expansion of the GSHP, combined with the ground heat exchanger in foundation piles and the seasonal thermal energy storage from solar thermal collectors, is extendable to more comprehensive applications.


Title of the Paper: Concentration of the Residual Carbon from Bottom Ash by Particle Size Separation

 

Authors: Mihai Cruceru, Bruno Valentim, Georgeta Predeanu, Traian Alexandru Abagiu, Valerica Slavescu, Lucica Anghelescu

Pages: 1-7

Abstract: In response to recent demand increases caused by emerging technologies, the European Commission (EC) established the Raw Materials Initiative to limit the impact that material supply shortages may have on the European economy. Natural graphite was identified as exhibiting a high supply risk and high economic importance. The paper presents the first stage of a research project which aims to demonstrate, by a detailed fundamental and applied investigation, the technical feasibility to utilize the bottom ash solid carbonaceous residue (char) as a substitute for graphite based materials. In this study, bottom ash samples from Oltenia lignite burned at Turceni and Govora power plants were sieved in order to assess the size fractions to be used for char concentration. Complementary analysis (proximate, elemental and calorific value) of Oltenia lignite and respective bottom ash samples were also conducted for a better understanding of the bottom ash properties. The experimental results highlight that the char from bottom ash can be concentrated using simple physical technologies.