Improved Pile Geometry to Reduce Negative Skin Friction on Single Driven Pile and Pile Groups Subjected to Lateral Loads

Geotechnical and Geological Engineering - Negative skin friction on piles represents a severe problem when piles were installed in soft clay due to consolidation process. It reduces the bearing...     

Morpho-Structural Study of the Korek Anticline,Zagros Fold-Thrust Belt,Kurdistan of Iraq

The present study is an attempt to construct a morpho-structural model for the Korek anticline that is located within the High folded zone of the Zagros Fold and Thrust Belt in the Northern Iraq-Kurdistan region. A detail geological map constructed for this structure, the stratigraphic succession that is exposed in the area was deposited from the middle Jurassic up to upper Cretaceous, and consists of nine formations. The most important morphological landscape and landforms in the studied area are due to endogenic and exogenic processes. Accordingly, the area is divided into four main units, which are units of structural, denudational, fluvial and solution origins. Each unit characterized by its own morphological feature differs from one another. According to structural point of view the field data are analyzed from two point of the viewing, one from map view and secondly from cross sections. The geometrical properties from map view of the Korek Anticline indicated that this fold is an asymmetrical double plunging, open to gentle, non-cylindrically curviplanar fold. The Korek Anticline becomes sharper with the depth, but broader and more open upward, this is one of the most characteristic features of the parallel fold (Class 1B). The presence of numerous reverse faults and strike-slip faults which affect the architecture of the Korek Anticline indicates that this Anticline formed by a Fault-propagation fold mechanism. Detailed balanced and retro-deformable cross sections along this anticline indicate that the shortening percentage can be differentiated in space and times, while the depth to detachment gives values that iscoincident with the Ora Shale Formation of Paleozoic age. A morpho-structural model was constructed for this structure and it consists of two main stages and five substages were responsible for the formation of the Korek structure. The first main stage belongs to structural construction, which consists of three sub-stages, while the main second stage is belonging to morphological destruction, which consist also two sub-stages. The effect of these stages and sub-stages makes the anticline to take the nowadays architects shape.     

A simple apparatus to study the effect of lithology,permeability, and wettability on spontaneous imbibition

The spontaneous imbibition phenomenon is an important process in hydrocarbon recovery. Laboratory study of imbibition is affected by many parameters including, rock characteristics, boundary conditions, length of the sample, variable interfacial tension, and sample heterogeneity. Investigating spontaneous imbibition enhances our understanding of the imbibition mechanism and, hence, helps improve waterflooding used in the oil industry. A simple apparatus has been developed to resemble naturally fractured reservoirs. Using the developed apparatus, the effects of lithology, permeability, and wettability on spontaneous imbibition have been experimentally investigated. Some encountered unexpected technical problems during the experiments are overcome and reported in this paper. Details of the developed apparatus are shown and spontaneous imbibition results are presented. First, the effect of permeability on the oil recovery rate is presented. In addition, obtained curves of oil recovery by water spontaneous imbibition using different lithology are presented. Finally, results of oil recovery from Berea sandstone core sample before and after wettability alteration are shown.     

Estimating of water erosion in semiarid regions using RUSLE equation under GIS environment

Water erosion is one of the main forms of land degradation in Algeria, with a serious repercussion on agricultural productivity. The purpose of this study is to estimate the soil loss of Wadi El-Ham watershed in the center of Algeria, this study aims also to evaluate the effectiveness and reliability of the use of the Revised Universal Soil Loss Equation (RUSLE) under a Geographic Information System in this field. The RUSLE model involves the main factors of erosion phenomena, namely, rain aggressiveness, soil erodibility, topographic factor, land cover index and the anti-erosive practices factor. Using this approach, the specific erosion in Wadi El-Ham watershed is estimated as 5.7 (t/ha/yr) in the entire watershed area. This result is compared to the measured suspended sediment at the Rocade-Sud gauging station situated outlet the watershed. These data consist of 1293 instantaneous measures of the water discharge and the suspended sediment concentration recorded during 21 years. Through this comparison, the used approach of RUSLE under GIS estimates the soil loss in Wadi El-Ham in Hodna region of Algeria with an error of 7.5%. Consequently, the results obtained in cartographic format make it possible to target the areas requiring priority action for a larger scale analysis to find appropriate solutions to combat erosion and to protect the natural environment.     

Perspectives for Distributed Observations of Near-Earth Space Using a Russian–Cuban Observatory

The creation of a specialized network of large, wide-angle telescopes for distributed observations of near-Earth space using a Russian–Cuban Observatory is considered. An extremely important goal of routine monitoring of near-Earth and near-Sun space is warding off threats with both natural and technogenic origins. Natural threats are associated with asteroids or comets, and technogenic threats with man-made debris in near-Earth space. A modern network of ground-based optical instruments designed to ward off such threats must: (a) have a global and, if possible, uniform geographic distribution, (b) be suitable for wide-angle, high-accuracy precision survey observations, and (c) be created and operated within a single network-oriented framework. Experience at the Institute of Astronomy on the development of one-meter-class wide-angle telescopes and elements of a super-wide-angle telescope cluster is applied to determine preferences for the composition of each node of such a network. The efficiency of distributed observations in attaining maximally accurate predictions of the motions of potentially dangerous celestial bodies as they approach the Earth and in observations of space debris and man-made satellites is estimated. The first estimates of astroclimatic conditions at the proposed site of the future Russian–Cuban Observatory in the mountains of the Sierra del Rosario Biosphere Reserve are obtained. Special attention is given to the possible use of the network to carry out a wide range of astrophysical studies, including optical support for the localization of gravitational waves and other transient events.     

Origin of disc lopsidedness in the Eridanus group of galaxies

The H  i surface density maps for a sample of 18 galaxies in the Eridanus group are Fourier analysed. This analysis gives the radial variation of the lopsidedness in the H  i spatial distribution. The lopsidedness is quantified by the Fourier amplitude A ₁ of the m = 1 component normalized to the average value. It is also shown that in the radial region where the stellar disc and H  i overlap, their A ₁ coefficients are comparable. All the galaxies studied show significant lopsidedness in H  i . The mean value of A ₁ in the inner regions of the galaxies (1.5–2.5 scalelengths) is ≥ 0.2. This value of A ₁ is twice the average value seen in the field galaxies. Also, the lopsidedness is found to be smaller for late-type galaxies; this is opposite to the trend seen in the field galaxies. These two results indicate a different physical origin for disc lopsidedness in galaxies in a group environment compared to the field galaxies. Further, a large fraction (∼30 per cent) shows a higher degree of lopsidedness ( A ₁≥ 0.3). It is also seen that the disc lopsidedness increases with the radius as demonstrated in earlier studies, but over a radial range that is two times larger than done in the previous studies. The average lopsidedness of the halo potential is estimated to be ∼10 per cent, assuming that the lopsidedness in H  i disc is due to its response to the halo asymmetry.     

Cenozoic denudation in the Marrakech High Atlas,Morocco: insight from apatite fission‐track thermochronology

In North Africa, the High Atlas belt culminates at more than 4000 m. In Morocco, recent work shows that a lithospheric thinning explains about 1000 m of the mean topography, the remaining topography being related to crustal shortening. We combine regional geology with new apatite fission‐track (AFT) ages to constrain the timing of these events in the Marrakech High Atlas (MHA). In the inner belt, 10 AFT ages are comprised between 9 ± 1 and 27 ± 3 Ma. These Neogene ages indicate that the MHA underwent significant denudation during that time. In the southern foreland domain of the belt, three samples give scattered AFT ages between 27 ± 2 and 87 ±5 Ma. Geological evidences allow us to constrain the age of a major denudation event during Middle Miocene age. We propose that it is linked to the thermal doming highlighted in the whole Moroccan Atlas domain.     

Assessment of heavy metals contamination in deposited street dusts in different urbanized areas in the city of Ma’an, Jordan

190 Street dust samples were collected from nine different localities including high traffic (desert highway), moderate traffic (city center), light traffic (minor streets), residential streets, school gardens, hospital and health centers, industrial sites, parks and background sites (control) of Ma’an area. The concentrations of Fe, Zn, Ni, Pb, Mn, Cu and Cd were analyzed by flame atomic absorption spectrophotometer to assess and to compare road dust contamination levels of metals among the different types of urban environment. The results showed that dust samples from the urban and industrial site contained significant levels of the metals studied compared to the values obtained from the background site. The variation in concentration of the heavy metals determined from different locations was in the decreasing order as: industrial > high traffic > parks > moderate traffic > hospital and health centers > school gardens > light traffic > background sites. The mean concentrations of the metals were in the order of C _Fe > C _Zn > C _Ni > C _Pb > C _Mn > C _Cu > C _Cd where C is the concentration of these metals in solution. Enrichment factor calculations indicated that Cd, Pb, Zn and Ni were highly enriched. Fossil fuel combustion, wear of brake lining materials, traffic emissions and several industrial processes are considered the main sources of these metals. Assessment of the contamination level in dust sample was estimated based on the geoaccumulation index (I _geo), the pollution index, and integrated pollution index (IPI). The values of IPI are in the following order: Pb > Zn > Cu > Ni > Cd > Mn. All the indices for the metals under consideration were either low or corresponded to middle level of contamination. The use of factor analysis showed that anthropogenic activities seem to be the responsible source of contamination for metals in dust samples.