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991.
The study area is located in the central part of the Eastern Desert of Egypt and is mainly covered by different varieties of Precambrian basement rocks represented mainly by younger and older granites, metadiorite, metavolcanics, and metasediments. The analysis and interpretation of airborne gamma-ray spectrometric survey data are essentially based on the computation of the three radioelements (U, Th, and K) favorability indices, estimation of uranium migration rate percentage, variation of eU with eTh and eU/eTh ratio, and the construction of the contour map of the (eU-eTh/3.5) in the different rock units. The highest percent of uranium migration- out or leaching rate is connected with the red and pink granites of Gebel Kadabora El-hamra, metadiorite, and red and pink granites of G. Umm Rakham (??20.8%, ??18.57%, and ??8.45% respectively), which indicates that they could represent a major U-source bodies in the area. It was observed that the metasediments and associated graphite-bearing schists west and northwest of G. Kadabora El-hamra reflect more precipitation than the other locations around the pluton (the uranium migration rates varies between 2.59 and 30%) which mean that the graphite may have acted as a reducing agent for uranium carried in oxidizing fluids (surface meteoric water) and resulted in its precipitation. In the light of the availability of uranium source, its mobility, and graphite-bearing metasediments, the area has a good potential for the possible occurrence of uranium mineralization.  相似文献   
992.
For the 1993–2009 period, we analyzed the relationship between almond yield and three climatic variables (mean annual temperature, soil water reserve, and precipitation), and four bioclimatic variables (annual ombrothermic index, water deficit, simple continentality index, and compensated thermicity index), for one major Hebron crop (soft and hard almonds). Moreover, we obtained data almond production from the Palestinian Central Bureau of Statistics, while the climate data from the Palestinian meteorological station during the study period from 1993 to 2009, and analysis is it by using bioclimatic classification of the Earth of Salvador Rivas-Martinez to study the relationship between the almond yield and climate and bioclimate factors (variables). The climatic and bioclimate variables of greatest importance to almond were used to develop regressions analysis relating yield to climatic conditions. Hebron was positively affected by annual ombrothermic index, simple continentality index, precipitation, water soil reserve, and mean annual temperature, but negatively affected by water deficit, with a large proportion of the variance explained by axis F1 (72.48%), F2 (22.38%), and axes F1and F2 (94. 86%). However, in order to produce a high amount of almonds and quality, it can be grown in the regions of the mesomediterranean region, with the value of annual ombrothemic index more than 3, compensated thermicity index between 220/220 to 350/350, simple continentality index between 14 and 20, and in areas where the average annual temperature is between 15 and 20 °C.  相似文献   
993.
Volumes of water in shallow wells of Ekiti State Southwestern Nigeria was estimated during the rainy and dry seasons of 2017 to categorize the area into different groundwater potential zones and to scrutinize it for groundwater sustainability and development. Locations of the wells were measured using etrex 12 Channel GPS while dip meter was employed for the water levels and depths of wells. The volume of water in a well was estimated employing V = πr2h (r and h are radius and water column of well, respectively). The wells in the area have low water storage (av. 6.91m3 and 2.70m3 in rainy and dry seasons, respectively). The study area had sufficient quantity of water in the rainy season to meet domestic, agricultural, and industrial requirements as deficiency was met from rainfall replenishment. Groundwater potential evaluation revealed that majority of the study area fell into very poor to poor water categories. Groundwater sustainability and development in the study area is a herculean task due to uncoordinated sitting of wells, low storage of water in the aquifers, and erratic occurrence of the groundwater. Hygiene education should be intensified in the area to forestall the risks post by the principal elements of fecal oral disease transmission.  相似文献   
994.
The Sisseb-ElAlem basin in central-eastern Tunisia contains several aquifers intensely used in agriculture. Highly exploited shallow aquifers are vulnerable to pollution and drought and reveal high salinity. Consequently, the new hydrogeological surveys were oriented to deep aquifers. The present work corresponds to study of 2D seismic sections, calibrated by water and petroleum wells, and geological outcrops. It highlights geometry and faulting of buried and preserved structures in depth and leads to identify the spatial distribution of Cenozoic potential reservoir layers in the different paleogeographic domains. The Sisseb-ElAlem basin is affected mainly by near E- and N-trending faults. Iso-depth and iso-thickness mapping were used to follow lateral and vertical variations of sedimentary series related to tectonics. The study area consists of Sisseb, Sbikha and El Ktifa uplifts, and El Alem, and Bled Saadia subsiding synclines. The Oligocene-Miocene reservoir series are exploited locally at the high borders. They reveal thickening and deepening southward in the El Alem-Bled Saadia domain, where they can be exploited at about 400 to 2000 m depths.This study should contribute to the orientation of water research to deeper aquifers, and therefore, ensure sufficient drinking and irrigation water supply mainly in areas called for sustainable development.  相似文献   
995.
An examination of river channels has ability to provide substantial information regarding the geomorphic characteristics, control of lithology, tectonic uplift and geomorphic evolution during the geological past of an area. In this paper, a detailed study of geomorphic and structural investigation has been carried out for Pravara basin, Maharashtra, with the help of 90-m resolution SRTM DEM and geospatial techniques. Drainage network analysis performed in this paper demonstrates the general geomorphic characteristics, while the analysis of longitudinal profile synthesises lithological control over Pravara basin. Pravara is a 6th order drainage basin, encompassing an area of 2637 km2. Bifurcation ratio reveals low to moderate structural control. Due to the hard rock lithology, the drainage density and stream frequency are low, and it indicates higher permeability in the sub-surface layers. The shape parameters denote that Pravara is highly elongated and it is easier to control floods in this basin. Relief parameters show very steep slope and higher vulnerability to the slope failure in some areas. Upstream of Pravara river has shown that series of breaks and knickzones indicate active erosion and acute lithological control on the channel. Major breaks are observed only in the main channel whereas in two major tributaries, no such breaks found, instead these tributaries are characterised by several knickzones which indicate regional variation in the lithological physiognomies. Different lithological stages on knickpoint and channel incision substantiate rejuvenation of Pravara river in several phases during geological past. The geospatial methodology carried out in this study can be pragmatic elsewhere around this world to recognise the geomorphic appearances and lithological control of a drainage basin.  相似文献   
996.
This study attempted to examine the effects of biochar amendment together with bio-fertilizer on soybean yield and its qualitative properties, as well as a few chemical properties of soil through a factorial randomized complete block design at three replications in east of Golestan Province (Iran) during 2014. The two factors under study included the following: (1) biochar amendment (in four levels of 0, 2.5, 8, and 16 tons per hectare), (2) bio-fertilizer containing phosphorus and sulfur growth-promoting rhizobacteria (in two levels of inoculation and non-inoculation) applied through foliar feeding. The results of analysis of variance indicated that interactions of biochar amendment and bio-fertilizer on harvest index and grain yield were significant (p ≤?0.01). According to the results of this study, the highest harvest index and oil content were 56.9, and 17.7%, respectively, in the treatment of 8 tons per hectare biochar and inoculation with bio-fertilizer. The lowest harvest index and the lowest oil content were in the control treatment. The interaction of biochar and bio-fertilizer on bulk density and cation exchange capacity was significant (p ≤?0.01). The results of this study demonstrated that biochar affected the amount of residual nitrogen in the soil after harvest, cation exchange capacity (CEC), acidity (pH), and electrical conductivity (EC). The highest grain yield (3440 kg/ha) was in the 8-ton biochar treatment with inoculated bio-fertilizer. Our study concludes that the biochar and bio-fertilizers can improve grain yield of soybean till 51% relative to the control.  相似文献   
997.
Developing the pore water pressures in loose to medium sands below the water table may lead to liquefaction during earthquakes. The simulation of liquefaction (cyclic mobility and flow liquefaction) in sandy soils is one of the major challenges in constitutive modeling of soils. This paper presents the simulation of sand behavior using a critical state bounding surface plasticity model (Dafalias and Manzari’s model, 2004) during monotonic and cyclic loading. The drained, undrained, and cyclic triaxial tests were simulated using Dafalias and Manzari’s model. The simulation results showed that the model predicts behavior of sand, reasonably well. Also, for CSR?<?0.2, number of cycles for liquefaction is significantly increased. The residual strength of Babolsar sand is produced when it is deformed to an axial strain of 20 to 25%.  相似文献   
998.
Aerosol optical depth (AOD), Angstrom exponent (AE), and ozone monitoring instrument aerosols index (OMI-AI) data, derived from MODerate Resolution Imaging Spectroradiometer (MODIS) and OMI sensor on board NASA’s Aqua satellite and NASA-Aura satellite platforms, have been analyzed and classified over Baghdad, Iraq, for an 8-year period (2008–2015). In order to give an obvious understanding of temporal inconsistency in the characteristics and classification of aerosols during each season separately, PREDE POM-02 sky radiometer measurements of AOD, carried out during a 2-year period (2014–2015), were compared with MODIS–Aqua AODs. On seasonal bases, MODIS–Aqua AODs corroborate well with ground-based measurements, with correlation coefficients ranging between 0.74 and 0.8 and RMSE ranging from 0.097 to 0.062 during spring and autumn seasons respectively. The overall satellite- and ground-based measurement comparisons showed a good agreement with correlation coefficients of 0.78 and RMSE of 0.066. These results suggest that MODIS–Aqua gives a good estimate of AOD. Analysis of MODIS–Aqua data for the 8-year period showed that the overall mean AOD, AE, and OMI-AI over Baghdad were 0.44?±?0.16, 0.77?±?0.29, and 1.34?±?0.33 respectively. AOD records presented a unique peak which was extended from mid-spring (April) to mid-summer (July) while the AE annual variability indicated a more complicated behavior with minimum values during the period from late spring (May) to early autumn (September). The maximum AOD and OMI-AI values occurred during summer while their minimum values occurred during winter. The AE showed an opposite behavior to that of AOD such that the highest AE values occurred during autumn and winter and the lowest values happened during spring and summer. This behavior may be attributed to the domination of coarse aerosol particles during autumn and winter seasons and fine aerosol particles during spring and summer seasons. A Hybrid Single-Particle Lagrangian Integrated Trajectory model was utilized to determine the source of air mass transport and to recognize the variability of aerosol origin regions. Finally, AOD, AE, and OMI-AI values have been employed to identify several aerosol types and to present seasonal heterogeneity in their contribution based on their origins.  相似文献   
999.
Temperature is one of the variables that influence the elasto-plastic behavior and integrity of rock outcrops. Fluctuations in temperature can trigger alteration of some of the mineral properties and impact the brittle-plastic transition. Initiation and propagation of thermally induced tension cracks tend to weaken most rock types. The principal goal of this study was to anticipate impacts of thermal stress-strain cycles on the dynamic response of representative rock units exposed in the Khewra Gorge of the Salt Range Punjab of Pakistan. Ten types of sedimentary rock units were sampled, including marl, dolomite, three types of limestone, and five different sandstones exhibiting varying characteristics in outcrop. Boulder specimens were collected from the field and transported to the laboratory to prepare 50 drill cores that could be subjected to thermal cycling between 50 and 200 °C in increments of 50 °C. Room temperature core samples were tested using an Erudite resonance frequency meter to measure their Q-factors and the resonance frequency (Fr) at an applied loading frequency of 7 KHz with 0.01 V output voltage. Results suggest that thermal cycling tends to reduce the dynamic Young’s modulus (Ed) and Q-factor. Other parameters, such as damping ratio (ξ), specific damping capacity (Ψ), and loss factor (?) appeared to increase with increasing temperature cycles, likely as a result of developing thermally induced tensile fractures. The resultant values of the null hypothesis (t-critical and t-stats) suggests that the null hypothesis can be discarded because there was no observable difference between the measured and expected values for the cores tested. The observations and data emanating from this study might be useful in designing low-level radioactive waste landfills, nuclear waste repositories, and deep underground excavations where the increased temperature could alter the mechanical behavior of the parent rock mass.  相似文献   
1000.
Soil contamination with cadmium has become major concern all over the world because of its adverse impacts on ecosystem health and agricultural land. Soil amendment with biochar may have varied effects on physical and chemical properties of soil. The objective of the study was to explore the impact of sugarcane filter-cake biochar on physiological performance and growth of lettuce in an aged soil. Four different doses (0, 1.5%, 3%, and 5%) of biochar were used in the soil and conditioned for 1 month. After this, lettuce seedlings were grown in the soil. The results showed that the biochar treatment improved the fresh and dry biomass of leaves and roots as well as plant height while diminished the bioavailability of cadmium from the soil. As compared to control, biochar significantly enhanced the chlorophyll content in lettuce leaves. Due to the biochar amendment, the oxidative stress decreased in lettuce shoots over the control. As compared to control, concentration of cadmium in lettuce significantly decreased after the application of biochar. It was concluded that biochar could mitigate the toxicity of cadmium in lettuce by altering the biochemical and physiological processes in cadmium contaminated soil.  相似文献   
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