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

In this research paper we have determined the enthalpy of the Fe-Ni alloy using the ‘STA’ equipment at the laboratory of the University of Mitrovica “Isa Boletini”, Department of Materials and Metallurgy. The sample for analysis was taken at the Ferronikel plant, whereas the preparation of the sample for analysis on the ‘STA PT 1600’ equipment took place at the laboratory of the University of Mitrovica ‘Isa Boletini’.
The sample of the Fe-Ni alloy analysed was 2–4 cm in size, in the shape of a granule. It contained, 22.55% Ni, 76.51% Fe, and small amounts of other elements [<xref ref-type="bibr" rid="j_rmzmag-2021-0012_ref_001">1</xref>, <xref ref-type="bibr" rid="j_rmzmag-2021-0012_ref_002">2</xref>]. During the analysis of the Fe-Ni alloy, we obtained three enthalpy values under analytical conditions that included a maximum temperature of 800 °C and a minimum temperature of 600 °C; the alloy was exposed to each temperature separately for 45 minutes at each temperature.
The results showed negative enthalpy values during the three scenarios examined and an exothermic process where ΔH&lt;0 [<xref ref-type="bibr" rid="j_rmzmag-2021-0012_ref_003">3</xref>]. The enthalpy decreases as the system releases heat with an increase in temperature [<xref ref-type="bibr" rid="j_rmzmag-2021-0012_ref_004">4</xref>].
</abstract>

Determining the Enthalpy of an Fe-Ni Alloy at Various Temperatures Using the ‘STA’ PT 1600 Equipment

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Cement-slag-bentonite slurry walls are self-hardening structures, and they are mainly used to retard contamination transport into the groundwater stream. Whilst permeability of a mixture is an initial criterion in slurry wall design and material selection, long-term performance is mainly influenced by curing ages and stress-state caused by adjacent soil. In this study, the steady-state of effective stresses at 7 days and 28 days of curing age is predicted. The effect of the modulus of horizontal subgrade reaction, interface friction, and transition of the earth pressure from at-rest to the active condition was applied to develop the model. Unlike the quantities that the geostatic model presented, this method gives a slight decrease of stresses after a certain depth, and the trend is in good agreement with trends provided by previous studies. Furthermore, the predicted stresses are then applied to estimate the permeability of the wall at each depth and compare it with those obtained in the laboratory. Finally, predicted effective stresses stay lower than geostatic stress, and the slurry wall consolidation along with the sidewalls’ lateral squeezing leads to keeping the stress state under control.
</abstract>

Lateral squeezing effects on cement-slag-bentonite slurry wall performance

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The granite of Abeokuta is part of the Older Granite suite of the basement complex of southwestern Nigeria. Field observation has identified the granite as porphyritic in texture, with a preferred alignment of megacrysts of K-feldspar >5 cm that are mostly euhedral to subhedral in shape. K-feldspar megacrysts are predominantly yellowish, but whitish and pinkish colouration has also been observed. The dark grey porphyritic, mafic rock composition occurs as enclaves within the granite, with phenocrysts having a preferred alignment as the enclosing granite. Also, K-feldspar megacrysts show zoning defined by concentric arrangement of inclusions of biotite relative to the crystal faces. Petrographic study shows the following minerals in order of abundance: K-feldspar, biotite, quartz, and plagioclase, with K-feldspar having a microperthitic intergrowth and biotite crystals aligned in a preferred direction. Evidence such as the crystal shape of K-feldspars, preferred alignment of K-feldspar phenocrysts, and concentric crystallographic arrangements of inclusions of biotite in K-feldspar support a magmatic/phenocrystic origin of K-feldspar megacrysts of Abeokuta granite rather than originating by growing in a solid state as porphyroblasts.
</abstract>

Field Observations, Petrography, and Microstructures of Granite from Abeokuta Southwestern Nigeria

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

The main objective of this study is the recovery of dune sands and rubber waste (powders). The latter constitutes a potential source of several environmental and economic problems.
The objective of this present work is to examine the ability to use dune sand for the preparation of mortars with sufficient physico-mechanical properties to allow them to be used in various building construction applications. The formulation of the mixtures is based on replacing dune sand with powders, at different weight contents: 10 %, 20 %, and 30 %. The quantity of cement is set at 450 <italic>g</italic>. The results obtained show in the first place that the particle size of the mixture tends to be spread out with a remarkable increase in the fineness modulus, and in the second place the density of the mixture decreases by 6.5 % (for the apparent) and by 10 % (for the absolute), which means the calculation of loads for the resulting mortar must decrease. Porosity has decreased to 20 % and absorption has increased to 30%. The strengths have decreased over 40 % for compressive strength and over 30 % for tensile strength, with an improvement in the relationship between the two strengths.
</abstract>

Valuation of Rubber Waste and Dune Sand: mortar for construction and environmental protection

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This research work discusses the phenomenon of land use and land cover, which has undergone constant changes over the past few decades due to major variations in the environment caused by anthropogenic and natural factors. This study is supported by a long time series of land use and land-cover satellite data of the Gambari Forest Reserve boundary map for 1984, 2004, and 2020. A maximum likelihood classification scheme was employed to classify the satellite imageries using ArcGIS 10.1 software to derive the spatial patterns and temporal variation of the land-use and land-cover change (LULC) classes: dense forest (DF), light forest (LF) and non-forest (NF). Data on deforestation of the study area showed that the area of DF increased from 31.7 km2 (23.4%) to 72.8 km2 (54.4%) within a 36-year time series, with a percentage change of 31.0%. The area of LF decreased from 79.2 km2 (65.4%) to 51.2 km2 (41.5%), with a percentage change of −23.9%, and that of NF decreased from 14.7 km2 (11.2%) to 2.6 km2 (4.1%), with a percentage change of −7.1%. This indicates that it would be reasonable to anticipate an increase in deforestation in the future.
</abstract>

Analysing the rate of land use and land-cover changes in Gambari Forest Reserve, Nigeria

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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. 