Convection flow over a uniform-flux vertical surface with variable viscosity

A regular perturbation analysis is presented for natural convection flow over an uniform flux vertical surface with temperature dependent viscosity. Numerical calculations are presented forP _r=6.7 which show that the first-order correction to the local temperature difference and to the local skin-fraction are negative whereas it is positive for the local Nusselt number. The effects of variable viscosity on the temperature, velocity profiles, the local temperature difference, the local Nusselt number and the local skin fraction are discussed.     

Multivariate analysis of heavy metal contents of sediments from Gumusler creek, Nigde, Turkey

In this study, heavy metal contents of samples from Gumusler creek in Turkey were studied and the metal contamination characteristics were investigated. In this respect, considering the pollutant sites in the area, systematic sediment samples were collected in a zone starting from the manifestation part of the water to the entrance of the Karasu creek in Gumusler town. Samples were taken from lower section of the river bed at 30 stations along Gumusler creek, 13 km in length and their heavy metal contents were analyzed with XRF Spectrometer. Correlation coefficients, element coefitic coefficient correlation, dendogram hierarchical cluster, model summary and Annova analysis statistical methods were applied to data. Strong positive correlations were determined for some elements which are believed to have possibly the same origin. In addition, mineralizations in the area are thought to cause variation in metal contents. Results of chemical analysis show that soil limit values and clark values were exceeded. The heavy metal accumulation in the creek is believed to be derived from non-operated Sb-Hg-W and Fe quarries.     

Geodynamics of the deep sedimentary basin of the Caspian Sea region: paragenetic correlation of seismicity and mud volcanism

In this paper we analyze seismic regime and earthquake depth distribution and correlation of seismicity and mud volcanism in the Azerbaijan and the Caspian Sea region. For the present region we have calculated accurate source locations, seismic activity, earthquake repetition and released earthquake energy parameters. It is shown that the active tectonic processes in the region are concentrated within the thick sedimentary cover that we consider as a general source of contemporary stress and a main structural element responsible for the origin of regional earthquakes. The correlation of seismicity and mud volcanism is of paragenetic character.     

Potential use of faujasite–phillipsite and phillipsite–chabazite tuff in purification of treated effluent from domestic wastewater treatment plants

Characterization of zeolitic tuff from Jabal Hannoun (HN) and Mukawir (MR) was carried out to examine the ability of using low-cost natural materials in domestic wastewater treatment. The grain size between 0.3 and 1 mm (0.3–1 mm) of the HN and MR has the highest total zeolite grade (faujasite–phillipsite and phillipsite–chabazite) and suitable cation exchange capacity. They were used as fixed-bed ion exchangers and adsorbents. The zeolitic tuff efficiently removed the organic and nitrogen compounds, Pb and Zn from the effluent. One bed volume (1 BV) of the zeolitic tuff is capable to remove up to 95 % of total organic carbon form 500 BV of the effluent. The removal percent of total nitrogen by HN and MR is close to 95 and 90 %, respectively. The zeolitic tuff has an excellent efficiency to remove Pb and Zn from the effluent. 1 BV of HN completely cleans Zn and Pb from 680 and 730 BV of the effluent, respectively, whereas 1 BV of MR is able to clean completely Zn and Pb from 500 and 685 BV of the effluent, respectively. The greater performance of the HN compared with the MR may be explained by its higher zeolites grade and presence of faujasite.     

Geophysical signature of the vien-type uranium mineralization of Wadi Eishimbai, Southern Eastern Desert, Egypt

The application of various geophysical tools with different responses succeeded in fixing U-mineralization in Wadi Eishimbai area. The area was studied using detailed ground spectrometric, magnetic, and filtered very low-frequency electromagnetic (VLF-EM) surveys. The interpretation of the obtained spectrometric maps clearly reflects the sharp increase of equivalent uranium (eU) content. Meanwhile, K and Th contents show sharp decreases. The eU/equivalent thorium (eTh) ratio correlates positively with eU concentrations and negatively with eTh concentrations, indicating an increase in U potentiality than the surrounding granite. The N?CS shear zone displays an eU content ranging from 20 to 140?ppm. The ENE-trending lamprophyre is characterized by elongated uranium anomalies trending in the E?CW direction, with values >90?ppm. Equivalent uranium content of the brecciated granite attains values up to 700?ppm. The ground magnetic and VLF-EM surveys played important roles in providing structural information which are proven useful in geological mapping and mineral exploration for the discovery of uranium mineralization in the study area. This study follows the expected subsurface extension of the Sela shear zone under Wadi sediments. The ground total magnetic intensity map shows a relatively narrow and an elongated shape for the lamprophyre anomaly extending for about 600?m in the Wadi toward the western direction. VLF-EM contour maps of the two used frequencies (17.1 and 28.5?kHz) show excellent agreement, indicating that the shear zone is distinguished with slightly strong conductivity westwards as an extension of the main shear zone. It is elongated in an ENE?CWSW trend and extends in the western direction, referring to the existence of conductive materials. Most of the NW/SE-trending faults cause sudden changes in the magnetic and VLF-EM contour spacing over an appreciable distance, which suggests a discontinuity in depth due to their left-lateral strike-slip displacements. The interpreted faults, with an ENE?CWSW trend representing the main trend of Sela shear zone through which hydrothermal solutions flowed, cause high alteration and uranium mineralization.     

Occurrence of diagenetic pseudobreccias within the paleokarst zone of the upper Dammam Formation in Kuwait, Arabian Gulf

A paleokarstic zone capping the Middle Eocene dolomitic Dammam Formation delineates a regional disconformity with the overlying Mio-Pleistocene fluvial deposits in Kuwait. This formation outcrops in a quarry located in the southeast of Kuwait and occurs in the subsurface of Umm Ghudair water field, west Kuwait. Karstification has affected the upper member of the Dammam Formation, which is formed of extensively chertified, vuggy chalky biodolomicrite. Karstification is manifested by two phases: a dissolution phase that was responsible for the occurrence of surface and near surface karst features and a precipitation phase during which a karst carapace and dolocretic and calcitic pseudobreccias were developed. Petrographic investigations of both the biodolomicrites host rock and the karst lithotypes revealed a complex diagenetic history that encompasses the following diagenetic events, arranged in a chronological order: (a) replacive dolomitization, (b) precipitative dolomitization, (c) precipitative silica, (d) replacive silica, (e) karstification, (f) development of karst carapace [calcretization and calcitization (development of calcitic psuedobreccia)], (g) dolocretization (development of dolocretic psuedobreccia), (h) mild karstification, (i) calcite precipitation, and (j) silica precipitation. The development of the karst carapace at the unconformity surface between the Eocene Dammam Formation dolomicrites and the overlying Mio-Pleistocene Kuwait Group clastics has played a significant role in the hydrological characteristics of Kuwait usable groundwater resources. It is recommended that the occurrence of similar diagenetic processes within the Arabian carbonate shelf deposits be investigated.     

The best fitting distribution of annual maximum rainfall in Peninsular Malaysia based on methods of L-moment and LQ-moment

This paper discusses patterns of annual and monthly precipitation variability at seven weather stations in east central Europe (1851–2007). Precipitation patterns were compared to three simple regional indices of atmospheric circulation, i.e., western circulation, southern circulation and the cyclonicity (C) index and a relationship between precipitation and the North Atlantic Oscillation index was identified. Correlations of the monthly records and multiple regression, using a principal components’ analysis, helped determine the statistical significance of the dependence of precipitation on the circulation indices. The Mann–Kendall test revealed no trend to change in any of the precipitation series, but a certain spatial regularity could be discerned in the phase of the annual periodic component. A common feature of the variability in central European annual precipitation is the dry period identified in the 1980s and the first half of the 1990s. In the northern part of the region, above-average precipitation was noted from the 1960s through to the mid-1970s as a result of the frequent prevalence of depressions. South of the divide, the wettest period was recorded at the turn of 1930s/1940s. After a number of very wet years in the last decade of the twentieth century and the beginning of the twenty-first century, precipitation began to fall at all of the region’s weather stations. The C index is the strongest circulation-linked factor influencing precipitation in central Europe and it accounts for more than 40% of the variance in spatially averaged wintertime precipitation.     

New occurrence of potential phosphate resource in northeast Jordan

An exploration program aided by field investigation, exploration drilling, detailed sampling, lithological and petrological studies, geochemical investigation, and resource calculation leads to the discovery of a potential phosphate resource in northeast Jordan close to the international border with Saudi Arabia and Iraq. The studied phosphate is of the Middle Eocene age that belongs to the Wadi Shallala Formation. It is equivalent to the phosphate deposits recorded in the lower part of the Umm Wual Formation in the Turayf region of Saudi Arabia and the Eocene Ratga Formation in the Ethna phosphate deposit west of Iraq. The phosphorites in the region are broadly similar in mineralogical composition and geochemical affinities. X-ray diffraction indicates the presence of francolite with variable amounts of calcite and quartz. Most samples consist of phosphate clasts embedded in carbonate and silica matrix and cement. P₂O₅ content is up to 32.3 % with an average equal to 18.6 %. The impurity is caused by the presence of variable amounts of SiO₂ and CaO. The F% and F/P₂O₅ ratio in studied phosphates is lower compared with that in phosphates from Jordan and Saudi Arabia. The geological and geochemical results were integrated for resource estimation. Three high-grade phosphate layers with ≥23 % P₂O₅ were considered in the calculations. The phosphate resource is classified as an inferred resource. The total volume of the resource is about 649 million tons. The average P₂O₅ content is 24.57, and the stripping ratio is 1:5.8.