Parameters controlling the quality of the Hamra Quartzite reservoir,southern Hassi Messaoud,Algeria: insights from a petrographic,geochemical, and provenance study

Petrographic and geochemical analysis of the Hamra Quartzite reservoir in the southern periphery of the Hassi Messaoud field has been undertaken. The aim is to identify the quality of these sandstones as well as their tectonic setting and possible provenance. Petrographic analysis reveals that the studied reservoir is constituted of fine- to coarse-grained sandstones in which quartz forms the principal framework mineral. The main cement phases identified in this reservoir are quartz, illite, and carbonate, precipitated in that order. The principal diagenetic factors controlling the reservoir quality are quartz overgrowths, formation of authigenic clays, and the precipitation of carbonate cement. The Hamra Quartzite reservoir is considered mature from a compositional point of view as it consists predominantly of quartz arenites. Geochemically, these sandstones have a high SiO₂ content (93.28–98.79 wt%). The Hamra Quartzite deposits appear to be derived from deeply weathered (under warm–humid climate conditions) granitic–gneissic terrains or recycled sedimentary source areas. A passive margin origin is the most likely tectonic setting for the depositional environment of these arenites. The reservoir quality is strongly influenced by the relationship between the clay content and mineralogy. The combined effect of quartz overgrowth and the plugging of pores by illite have reduced both porosity and permeability. As a result, economically viable oil production in this area will depend most strongly on the combination of matrix and fracture porosity.     

西准白杨河铍矿床萤石及流体包裹体特征

利用激光测温学和激光拉曼光谱方法,通过镜下观察,研究了白杨河铍矿床与铍成矿作用有关的脉石矿物(萤石),将萤石分为4个期次,其中第三期萤石与铍成矿关系最密切。萤石流体包裹体具低盐(0.7%~7.0%)、低温(89.7℃~188.9℃)的特征,第三期萤石脉流体包裹体成矿温度99.4℃~120.5℃,成矿盐度3.5%~5.4%,与铍矿物属同一期,揭示出该矿床成矿流体为低温、低盐度热液。     

Numerical study of power production from tidal energy in the Khuran Channel and its feedback on background hydrodynamics

This study focuses on the development of a farm of tidal turbines in the Khuran Channel. The important factors include the location of turbines and their hydrodynamic effects on the environment. A three-dimensional circulation model for the Persian Gulf is employed for the comprehensive evaluation of the tidal energy potential throughout the study area. The model is validated by using in situ observations of water level and current data.The appropriate potential points for extracting the tidal e...     

The Translational–Rotational Motion of an Earth Spheroid Satellite

In this paper we consider the translational–rotational motion of a spheroid satellite in the gravitational field, taking into account the asphericity of the earth. The harmonic coefficients of the earth’s gravitational field are taken up to J ₄. The equations of motion are obtained in terms of the canonical elements of Delaunay-Andoyer. A first order solution is obtained using the perturbing technique of Lie series.     

Application of the honey-bees mating programming (HBMP) algorithm to sediment concentration modelling

Abstract

The honey-bees mating programming (HBMP) algorithm is introduced as a novel tool for predicting suspended sediment concentration for the Mad River catchment near Arcata, USA. The paper also applies gene expression programming (GEP) as a comparison and shows that these two approaches can the produce transparent, nonlinear relationships between the independent and dependent variables. Some modifications have been made to the HBMP algorithm to improve its capability and efficiency. The results achieved from this method and GEP are compared with two different sediment rating curves based on regression techniques. The findings show that the results from both the HBMP and GEP methods are promising and outperform the results obtained from the sediment rating curves.

Editor D. Koutsoyiannis; Associate editor L. See     

Magnetic Removal of Reactive Black 5 from Wastewater Using Ionic Liquid Grafted‐Magnetic Nanoparticles

Due to the unique chemical properties and therefore wide range of applications, significant amounts of reactive dyes often end up in waste waters and this issue raises the need for more efficient treatment technologies. This work investigates the ability of magnetite nanoparticles functionalized with imidazolium based ionic liquid (IL) as an efficient sorbent for the removal of the Reactive black 5 from wastewater. Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, thermo‐gravimetric analysis, and zeta potential measurement were used to characterize the synthesized nanosorbent. The results showed that under optimal conditions, the dye removal efficiency of the grafted IL is 98.5% after a single run. Regeneration of the used sorbent could be possible and the modified magnetic nanoparticles exhibited good reusability. The isothermal data of RB5 sorption conformed well to the Langmuir model and the maximum sorption capacity of IL@Fe₃O₄ for RB5 was 161.29 mg g^?1. Thermodynamic study indicated that the adsorption is endothermic and spontaneous. The use of such a system can provide fast and efficient removal of the reactive dyes from wastewater by using an external magnetic field.     

Identifying geological hazards related to tunneling in carbonate karstic rocks - Zagros, Iran

The construction of tunnels in carbonate karstic rocks has always been the most hazardous and problematic task in civil and mining engineering, as it can threaten tunneling project from safety, time and economic aspects. Therefore, it is essential to identify hazards resulting from construction in early stages of a project. The present paper is aimed to identify main geological hazards related to tunneling in carbonate karstic rocks in the Zagros Mountains. The process of identification relies upon a review of construction experiences obtained from several projects with a focus on the Kuhrang Tunnels. Obviously, groundwater inrush and tunnel flooding, ground inflow and fill-back of the tunnel, instability of weak fill materials, and TBM jamming are the main potential hazards of tunneling in the Zagros Mountains, imposing huge problems during construction. Inadequate understanding of hazards and not being prepared enough to take appropriate countermeasures are the main sources of the problems. In addition, the investigation of the present study provides guidelines to reduce the risks of tunneling in the carbonate karstic rocks with similar geological condition.     

Influence of climate, mineralogy and mineral processing on the weathering behaviour within two, low-sulfide, high-carbonate, gold mine tailings in the Eastern Desert of Egypt

Despite its importance within environmental management strategies, little concern is shown to sulfide oxidation and/or hardpan formation at neutral pH where dry condition prevails. Two gold mine tailings in Egypt, El Sid and Barramiya, were studied for their geochemical/mineralogical properties, and climate influence on hardpan formation. The tailings are characterised by homogeneous silt-sized sediments (>42%), have high carbonate, predominantly as calcite for El Sid and dolomite-ankerite for Barramiya, and low-sulfide contents, chiefly as pyrite, galena and sphalerite for El Sid, and arsenopyrite–pyrite for Barramiya. El Sid is characterised by high average concentrations of Pb (2,758 mg/Kg) and Zn (2,314 mg/Kg), its lower part dominated by mafics, overlaid by granitoids. Barramiya has higher As (average 2,836 mg/Kg) content and represents a mixture of mica-schists/mafics-ultramafics. During field investigations, no hardpans were identified, only bassanite and gypsum were found at the surface of El Sid tailings, forming thin layers and desiccation crack fillings. Column experiments showed a thin crust consisting of gypsum, halite and sodium sulfate formed at the top of the column of El Sid tailings after 2 weeks, this was not recognized in the column from Barramiya. The homogenous thickened tailings deposition in both areas did not favour hardpan formation, since the critical amounts of reacting sulfides were never achieved in individual lamina, due to missing mineral/grain size fractionation. The high-temperature/low-water availability, characteristic for desert climate regions did not allow significant sulfides oxidation. Therefore, both tailings will suffer from continuous erosion and spreading out of contaminants to the environment for a prolonged period of time by sporadic flash floods.     

Turbulence-particle interactions under surface gravity waves

The dispersion and transport of single inertial particles through an oscillatory turbulent aquatic environment are examined numerically by a Lagrangian particle tracking model using a series of idealised test cases. The turbulent mixing is incorporated into the Lagrangian model by the means of a stochastic scheme in which the inhomogeneous turbulent quantities are governed by a one-dimensional k- ε turbulence closure scheme. This vertical mixing model is further modified to include the effects of surface gravity waves including Coriolis-Stokes forcing, wave breaking, and Langmuir circulations. To simplify the complex interactions between the deterministic and the stochastic phases of flow, we assume a time-invariant turbulent flow field and exclude the hydrodynamic biases due to the effects of ambient mean current. The numerical results show that the inertial particles acquire perturbed oscillations traced out as time-varying sinking/rising orbits in the vicinity of the sea surface under linear and cnoidal waves and acquire a non-looping single arc superimposed with the high-frequency fluctuations beneath the nonlinear solitary waves. Furthermore, we briefly summarise some recipes through the course of this paper on the implementation of the stochastic particle tracking models to realistically describe the drift and suspension of inertial particles throughout the water column.