Issues

Journal & Issues

AHEAD OF PRINT

Volume 67 (2020): Issue 4 (December 2020)

Volume 67 (2020): Issue 3 (September 2020)

Volume 67 (2020): Issue 2 (June 2020)

Volume 67 (2020): Issue 1 (March 2020)

Volume 66 (2019): Issue 4 (December 2019)

Volume 66 (2019): Issue 3 (December 2019)

Volume 66 (2019): Issue 2 (June 2019)

Volume 66 (2019): Issue 1 (March 2019)

Volume 65 (2018): Issue 4 (December 2018)

Volume 65 (2018): Issue 3 (September 2018)

Volume 65 (2018): Issue 2 (September 2018)

Volume 65 (2018): Issue 1 (March 2018)

Volume 64 (2017): Issue 4 (December 2017)

Volume 64 (2017): Issue 3 (September 2017)

Volume 64 (2017): Issue 2 (July 2017)

Volume 64 (2017): Issue 1 (March 2017)

Volume 63 (2016): Issue 4 (December 2016)

Volume 63 (2016): Issue 3 (September 2016)

Volume 63 (2016): Issue 2 (July 2016)

Volume 63 (2016): Issue 1 (May 2016)

Journal Details
Format
Journal
eISSN
1854-7400
First Published
30 Mar 2016
Publication timeframe
4 times per year
Languages
English

Search

Volume 64 (2017): Issue 1 (March 2017)

Journal Details
Format
Journal
eISSN
1854-7400
First Published
30 Mar 2016
Publication timeframe
4 times per year
Languages
English

Search

5 Articles
Open Access

Structural drilling using the high-frequency (sonic) rotary method

Published Online: 01 Jun 2017
Page range: 1 - 10

Abstract

Abstract

In Slovenia, there is widespread use of structural drilling along with classical core drilling. Recently, however, the need has arisen for a highly effective core drilling method with the aid of which high-quality core might be obtained. In order to achieve this aim, one among several Slovenian companies dealing with geological surveying has decided to implement structural drilling using a high-frequency drilling method. The following article presents the theoretical foundations for such a high-frequency method, as well as the manner of its implementation. In the final part of the article, a practical comparison between the conventional and the high-frequency core drilling methods is also provided.

Keywords

  • structural drilling
  • high-frequency method
  • core drilling
  • sonic drilling
Open Access

Influence of cooling mode in relation to casting and extrusion parameters on mechanical properties of AA6082

Published Online: 01 Jun 2017
Page range: 11 - 20

Abstract

Abstract

In this study, conditional average estimator neural networks (CAE NNs) were used for an analysis of the common influences of the cooling mode in relation to the ram speed, extrusion ratio, casting speed and casting temperature on the yield strength and the elongation of an extruded profile made from aluminium alloy (AA)6082. The obtained results from the analysis revealed very complex relationships between these parameters. In order to maximise the values for the yield strength and the elongation, the values for the ram speed, extrusion ratio, casting speed and casting temperature should be optimised in relation to the mode of cooling.

Keywords

  • AA6082
  • intermetallic phases
  • hot extrusion
  • mechanical properties
  • neural networks
Open Access

Diversity of Soil Microbial Communities from an Iron Mining Area (Oued Zem, Morocco)

Published Online: 01 Jun 2017
Page range: 21 - 34

Abstract

Abstract

Microbial communities in the soil were collected from 20 samples of an iron mining area (Ait Ammar, Oued Zem, Morocco), and unaffected samples were analysed to identify the effects of metal concentrations on functional diversity (Biolog® EcoPlates), and structural diversity (polymerase chain reaction-denaturing gradient gel electrophoresis of 16S rDNA). Aliivibrio fischeri is mainly used for evaluating polluted soil. The functional diversity was assessed by using such indices as area under substrate utilisation curve, richness, Shannon- Weaver and evenness indices. The analysis of similarities and the non-metric multidimensional scaling analyses of DGGE profiles showed that metals in the soil do not have a significant influence on bacteria. Principal component analysis of Biolog data revealed the similarity in the metabolic profiles of mining samples. These results suggest that the direction and the distance from the iron mine tailings do not have significant effects on the metabolic and structural diversity of the soil bacterial population. The toxicity of metals in soils heavily contaminated with Fe and P did not affect the quantities of microbial populations and did not significantly change the microbial diversity of contaminated soils.

Key words

  • Biolog® EcoPlates
  • PCR-DGGE
  • Microtox®
  • microbial communities
  • iron mine
Open Access

Geochemistry of Fluvial Sediments from Geregu, Southwest Nigeria

Published Online: 01 Jun 2017
Page range: 35 - 52

Abstract

Abstract

Geochemical analysis of fluvial sediments on the banks of River Ero using inductively coupled plasma mass spectrometry illustrates their maturity, provenance and tectonic setting. The analysed sediment samples show low SiO2/Al2O3 ratios of 2.92-2.99 (units FL_A, FL_B and FL_E) and high SiO2/Al2O3 ratios of 4.064-4.852 (units FL_C, FL_D, FL_F and FL_G). Sediments were geochemically classified as shales (units FL_A, FL_B and FL_E) and greywackes (units FL_C, FL_D, FL_F and FL_G). Variability in sediment maturity (FL_F > FL_G >FL_C >FL_D >FL_A > FL_B > FL_E) parallels a decreasing order in the ratios of SiO2/Al2O3 and K2O/Al2O3, as well as the proportion of quartz grains and matrix components. Evidence from Al2O3/TiO2, K2O, Rb, La/Co, Th/Co, Cr/ Th, Th/Cr, La/Th-Hf, Th-Hf-Co and rare earth element contents of sediment samples suggest felsic protoliths of upper continental crust in a passive margin tectonic setting. An insignificant contribution of mafic components from the source is, however, inferred based on the Ni and Cr contents of the sediment samples. Combined Eu anomalies <0.85 and (Gd/Yb)n ratios <2.0 (1.53- 1.82, average 1.65) suggest post-Archean protoliths.

Keywords

  • Fluvial sediments
  • Eu anomaly
  • Southwest Nigeria
  • Provenance
  • Tectonic setting
Open Access

The flexural stiffness and tension state of basalt filter

Published Online: 01 Jun 2017
Page range: 53 - 62

Abstract

Abstract

In recent years, there is a growing demand in Uzbekistan for new, cheap and competitive products from local raw materials, the demand being directly connected with the expansion and development opportunities of the mining, metallurgical and processing industries. In such conditions, the need for providing a solution of the problems faced by these industries is a very urgent one and requires further comprehensive studies. One of these tasks includes assessment of the force parameters and bending stiffness of basalt fibre filters, aimed at further improving the efficiency of local basalt raw materials and aiding in the manufacture of new, long-lasting, reliable and high-quality products. In this case, we studied the interaction of basalt fibre filter with a gas or liquid medium, the deformed state of the fibres under the action force of the gas or liquid, and the filter recovery process after removal of the load, all of which occur during mechanical filtration. These tasks are of interest because during the mechanical filtration of a gas or liquid (hereinafter, mechanical filtration) from solids, all attention is paid to the quality of the filtering process. The filtering quality, as known, is determined by the degree of contamination in the liquid undergoing treatment, duration of separation of the pulp into solid and liquid phases during the decantation process of the mixture and the amount of gas/ liquid released into the atmosphere along with carbon monoxide and toxic impurities. At the same time, the state and behaviour of the filtering material remain as minor factors, the consideration of which can play a decisive role in the establishment of filter life and work capacity. Solutions to these problems are very urgent and allow one to create new technologies for the production of basalt filters based on force parameters and bending stiffness, wherein the purification occurs without the intervention of chemicals.

Keywords

  • filter
  • basalt rock
  • research
  • gas flow
  • gas purifying facilities
  • process variable
  • filter material
5 Articles
Open Access

Structural drilling using the high-frequency (sonic) rotary method

Published Online: 01 Jun 2017
Page range: 1 - 10

Abstract

Abstract

In Slovenia, there is widespread use of structural drilling along with classical core drilling. Recently, however, the need has arisen for a highly effective core drilling method with the aid of which high-quality core might be obtained. In order to achieve this aim, one among several Slovenian companies dealing with geological surveying has decided to implement structural drilling using a high-frequency drilling method. The following article presents the theoretical foundations for such a high-frequency method, as well as the manner of its implementation. In the final part of the article, a practical comparison between the conventional and the high-frequency core drilling methods is also provided.

Keywords

  • structural drilling
  • high-frequency method
  • core drilling
  • sonic drilling
Open Access

Influence of cooling mode in relation to casting and extrusion parameters on mechanical properties of AA6082

Published Online: 01 Jun 2017
Page range: 11 - 20

Abstract

Abstract

In this study, conditional average estimator neural networks (CAE NNs) were used for an analysis of the common influences of the cooling mode in relation to the ram speed, extrusion ratio, casting speed and casting temperature on the yield strength and the elongation of an extruded profile made from aluminium alloy (AA)6082. The obtained results from the analysis revealed very complex relationships between these parameters. In order to maximise the values for the yield strength and the elongation, the values for the ram speed, extrusion ratio, casting speed and casting temperature should be optimised in relation to the mode of cooling.

Keywords

  • AA6082
  • intermetallic phases
  • hot extrusion
  • mechanical properties
  • neural networks
Open Access

Diversity of Soil Microbial Communities from an Iron Mining Area (Oued Zem, Morocco)

Published Online: 01 Jun 2017
Page range: 21 - 34

Abstract

Abstract

Microbial communities in the soil were collected from 20 samples of an iron mining area (Ait Ammar, Oued Zem, Morocco), and unaffected samples were analysed to identify the effects of metal concentrations on functional diversity (Biolog® EcoPlates), and structural diversity (polymerase chain reaction-denaturing gradient gel electrophoresis of 16S rDNA). Aliivibrio fischeri is mainly used for evaluating polluted soil. The functional diversity was assessed by using such indices as area under substrate utilisation curve, richness, Shannon- Weaver and evenness indices. The analysis of similarities and the non-metric multidimensional scaling analyses of DGGE profiles showed that metals in the soil do not have a significant influence on bacteria. Principal component analysis of Biolog data revealed the similarity in the metabolic profiles of mining samples. These results suggest that the direction and the distance from the iron mine tailings do not have significant effects on the metabolic and structural diversity of the soil bacterial population. The toxicity of metals in soils heavily contaminated with Fe and P did not affect the quantities of microbial populations and did not significantly change the microbial diversity of contaminated soils.

Key words

  • Biolog® EcoPlates
  • PCR-DGGE
  • Microtox®
  • microbial communities
  • iron mine
Open Access

Geochemistry of Fluvial Sediments from Geregu, Southwest Nigeria

Published Online: 01 Jun 2017
Page range: 35 - 52

Abstract

Abstract

Geochemical analysis of fluvial sediments on the banks of River Ero using inductively coupled plasma mass spectrometry illustrates their maturity, provenance and tectonic setting. The analysed sediment samples show low SiO2/Al2O3 ratios of 2.92-2.99 (units FL_A, FL_B and FL_E) and high SiO2/Al2O3 ratios of 4.064-4.852 (units FL_C, FL_D, FL_F and FL_G). Sediments were geochemically classified as shales (units FL_A, FL_B and FL_E) and greywackes (units FL_C, FL_D, FL_F and FL_G). Variability in sediment maturity (FL_F > FL_G >FL_C >FL_D >FL_A > FL_B > FL_E) parallels a decreasing order in the ratios of SiO2/Al2O3 and K2O/Al2O3, as well as the proportion of quartz grains and matrix components. Evidence from Al2O3/TiO2, K2O, Rb, La/Co, Th/Co, Cr/ Th, Th/Cr, La/Th-Hf, Th-Hf-Co and rare earth element contents of sediment samples suggest felsic protoliths of upper continental crust in a passive margin tectonic setting. An insignificant contribution of mafic components from the source is, however, inferred based on the Ni and Cr contents of the sediment samples. Combined Eu anomalies <0.85 and (Gd/Yb)n ratios <2.0 (1.53- 1.82, average 1.65) suggest post-Archean protoliths.

Keywords

  • Fluvial sediments
  • Eu anomaly
  • Southwest Nigeria
  • Provenance
  • Tectonic setting
Open Access

The flexural stiffness and tension state of basalt filter

Published Online: 01 Jun 2017
Page range: 53 - 62

Abstract

Abstract

In recent years, there is a growing demand in Uzbekistan for new, cheap and competitive products from local raw materials, the demand being directly connected with the expansion and development opportunities of the mining, metallurgical and processing industries. In such conditions, the need for providing a solution of the problems faced by these industries is a very urgent one and requires further comprehensive studies. One of these tasks includes assessment of the force parameters and bending stiffness of basalt fibre filters, aimed at further improving the efficiency of local basalt raw materials and aiding in the manufacture of new, long-lasting, reliable and high-quality products. In this case, we studied the interaction of basalt fibre filter with a gas or liquid medium, the deformed state of the fibres under the action force of the gas or liquid, and the filter recovery process after removal of the load, all of which occur during mechanical filtration. These tasks are of interest because during the mechanical filtration of a gas or liquid (hereinafter, mechanical filtration) from solids, all attention is paid to the quality of the filtering process. The filtering quality, as known, is determined by the degree of contamination in the liquid undergoing treatment, duration of separation of the pulp into solid and liquid phases during the decantation process of the mixture and the amount of gas/ liquid released into the atmosphere along with carbon monoxide and toxic impurities. At the same time, the state and behaviour of the filtering material remain as minor factors, the consideration of which can play a decisive role in the establishment of filter life and work capacity. Solutions to these problems are very urgent and allow one to create new technologies for the production of basalt filters based on force parameters and bending stiffness, wherein the purification occurs without the intervention of chemicals.

Keywords

  • filter
  • basalt rock
  • research
  • gas flow
  • gas purifying facilities
  • process variable
  • filter material

Plan your remote conference with Sciendo