<abstract xmlns="http://www.w3.org/1999/xhtml">

This work deals with the characterisation of the microstructure of a nickel insert, a special copper alloy and the cast joint between them after their use as a glass manufacturing mould. The microstructure was characterised by optical microscopy, scanning electron microscopy and microanalysis by energy dispersive X-ray spectroscopy.
It was found that the nickel insert contained 7 at. % Si and 0.3 at. % Fe. The special copper alloy contains undesirable phases or compounds, including lead, aluminium-based oxides and borides. The borides are either iron-, iron-chromium- or chromium-based with different stoichiometries between metal components and boron. The cast joint between the nickel insert and the special copper alloy has evidence of mixing the two alloys, while only in some areas porosity and oxides prevented the formation of a suitable cast joint. Aluminium-based oxides and some borides could be the cause of the formation of cracks due to their morphology.
</abstract>

Microstructure of a nickel insert, a special copper alloy, and a cast joint between them

<abstract xmlns="http://www.w3.org/1999/xhtml">

Rare earth elements (REE) are critical metals widely used in modern technology. There is an increased demand for these elements which has necessitated additional exploration. The REE geochemistry of syenites and charnockitic rocks from selected locations within southwestern Nigeria were studied to determine their concentrations, distribution patterns, and mineralisation potential to deduce if they can be economically exploited. Mineralogical studies were carried out using scanning electron microscopy (SEM). Ten rock samples including five syenites and five charnockites were analysed for their elemental composition using inductively coupled plasma – mass spectrometry (ICP-MS). The REE-bearing minerals identified from the SEM analysis include apatite and monazite. The fractionation ratio (La/Yb)N ranged from 29.36 to 48.75 for the syenites and from 24.43 to 48.29 for the charnockites, indicating magmatic differentiation. Total REE (∑REE) in the syenites (342–675 ppm) and charnockites (220–802 ppm) suggests that they are enriched with respect to REE but the REE concentration in the rocks of the study area had very low ∑REE compared to the REE contents of the rocks where they have been mined and may therefore not be economically viable.
</abstract>

Rare Earth Element Geochemistry and Abundances in Syenites and Charnockitic Rocks of Selected Locations within Southwestern Nigeria

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The spectral analysis of aeromagnetic data over the study area (Northern basement complex, Nigeria) revealed the existence of two major source depths. The second segment of the spectrum layer shows shallow sources ranging in depth from 0.135 km to 0.201 km, with an average depth of 0.140 km. The depth to the basement or deeper source ranges between 1.655 km and 2.021 km, with an average depth of 1.882 km. The Precambrian basement is reflected in the deeper sources, beginning with the first segment of the power spectrum. Structural and topographic relief of the basement surface, lateral differences in basement susceptibilities, and intra-basement features such as faults and fractures contribute to the variation in basement composition. The mean thickness of sediments in the study area is represented by the D2 values obtained from the spectral plots. The depths revealed by this study appears to be reasonable and consistent with previous researchers’ findings. Tectonically active regions have a major impact on heat flows. The average heat flow in thermally normal continental regions is reported to be above 60 mW/m2. Values between 80 and 100 mW/m2 indicate a good geothermal source; values in excess of about 80–100 mW/m2 indicate anomalous geothermal conditions.
</abstract>

Solid Mineral Potential and Geothermal Energy Reserve of Northern Basement Complex, Nigeria

<abstract xmlns="http://www.w3.org/1999/xhtml">

Geophysical investigations involving very low frequency electromagnetic (VLF-EM) and vertical electrical sounding (VES) techniques were deployed to study the pavement failure along a major road in a typical basement complex terrain of southwestern Nigeria. This study was designed to assess the failure and provide a basis for ultimate engineering design. The study delineated a 3- to 4-layer geoelectric sequence: a topsoil of thickness varying from 0.4 to 1.2 m, a spectrum of clayey materials of thickness varying from 1.9 to 14.5 m and a weathered/fractured basement occurring at depths of between 3.6 and 15.0 m. The shallow basement indicated low bearing capacity, with resistivity values ranging from 62.1 to 377.9 Ωm. The presence of clay/clayey materials, linear features and the effect of rising water table within the influence zone underlined the pavement failure. This information will facilitate appropriate designing, soil improvements and selection of materials for road construction that can stand the test of time.
</abstract>

Integration of VLF-EM and VES data for pavement failure investigation in a typical basement complex terrain of southwestern Nigeria

<abstract xmlns="http://www.w3.org/1999/xhtml">

As a result of a combination of several methodologies, the H-Field, Niger-Delta, has been delineated. To identify probable reservoirs, seals, and source rocks in the study area, this study integrates sequence stratigraphy with petrophysical concepts through a comprehensive analysis of 3D seismic and well logging datasets. According to the 3D facies model, reservoirs are dominated by sand and are laterally extensive. They were then upscaled and stochastically distributed to create a 3D reservoir property model. On average, the porosity of these clastic reservoirs ranges from 22 to 28%. Reservoir net-to-gross (NTG) ratios range from 0.67 to 0.96. Water saturation ranges from 8% to 30%, while hydrocarbon saturation ranges from 70% to 92%. Four gas-bearing units and six oil-bearing units are present in reservoirs P 0.5 and P 1 compartments. All reservoir intervals’ oil and gas volumes are evaluated based on the hydrocarbon distribution. Geological models of the subsurface, such as the one in this paper, are crucial for future reservoir development programs.
</abstract>

Petrophysical Evaluation of H-field, Niger Delta Basin for Petroleum Plays and Prospects

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Materials and Geoenvironment

 Description:  Old title: Rudarsko-metalurški zbornik (Mining and Metallurgy Quaterly).  Is issued quarterly by the Faculty of Natural Sciences and Engineering, Ljubljana, Velenje Coal Mine, Velenje, Institute for Mining, Geotechnology and Environment (IRGO), Ljubljana and Slovenian Chamber of Engineers, Ljubljana.  Financially supported also by Ministry of Higher Education, Science and Technology Republic of Slovenia.  Issues up to the volume 62 you can find on our old web page at address: www.rmz-mg.com/contents.htm  The journal does not have article processing charges (APCs) nor article submission charges.  Archiving  Sciendo archives the contents of this journal in Portico - digital long-term preservation service of scholarly books, journals and collections.  Plagiarism Policy  The editorial board is participating in a growing community of Similarity Check System's users in order to ensure that the content published is original and trustworthy. Similarity Check is a medium that allows for comprehensive manuscripts screening, aimed to eliminate plagiarism and provide a high standard and quality peer-review process. 