Dynamic vertical compliance of strip foundations in layered soils

In this paper, results of a detailed investigation on the dynamic response of rigid strip foundations in viscoelastic soils under vertical excitation are presented. An advanced boundary element algorithm developed by incorporating isoparametric quadratic elements and a sophisticated self-adapting numerical integration scheme has been used for this investigation. Foundations supported on three types of soil profiles, namely, homogeneous half-space, stratum-over-half-space and stratum-over-bedrock are considered. The influence of material properties like Poisson's ratio and material damping as well as the influence of geometrical properties such as depth of embedment and layer thickness are studied. The effect of the type of contact at the soil-foundation interface is also investigated.     

Eco-friendly smart hydrogels for soil conditioning and sustain release fertilizer

In the agricultural industry, biomass waste generated along with the production of food, is transformed into value-added products. Also, the demand for the slow or control release fertilizer is increasing to reduce the cost of maintaining the agricultural land. These issues are tackled by converting biomass waste to a slow fertilizer release vehicle and biodegradable water retention material that could reduce the cost for fertilizer application and simultaneously preserved the soil from dryness. A series of carboxymethyl sago pulp (CMSP) hydrogels were prepared by electron beam irradiation. Slow release systems were evaluated by loading potassium nitrate (KNO₃) and ammonium nitrate (NH₄NO₃) into the CMSP hydrogels. These CMSP hydrogels endow slow release property, biodegradability and a soil moisture preservation property that could find greener application in agricultural industries. The results indicate that CMSP hydrogels have a great potential as an agent for slow release of fertilizers.     

Peculiar motions of galaxy clusters: correlation function approach

The correlation function theory on the basis of prescribed boundary conditions provides a deeper understanding in studying the dynamical parameters of galaxy clusters. The approach approximates that the moderate dense systems discussed by a two point correlation function is helpful for describing the dynamical nature of galaxy clusters. The projected theory of two point correlation function for point mass and extended mass structures can be used an alternative tool in measuring the average peculiar motion and temperature profile of galaxy clusters.     

Numerical simulation of damage–Permeability relationship in brittle geomaterials

Finding a coupling model between a hydraulic parameter such as permeability and a mechanical parameter such as damage is the key element for several recent engineering problems. A review of the technical literature reveals that several mechanical constitutive laws exist which allow determining a damage tensor for a damageable porous material under loading. But the present work develops a method to deduce the permeability change due to the damage propagation.     

Mineralogy, geochemistry, and origin of felsic dike swarms in Aqaba complex (Wadi Al-Yutum), South Jordan

The present work deals with the geologic setting and mineralogical and geochemical study of Late Precambrian magmatic rocks especially the felsic dike swarms of northeast Aqaba complex in South Jordan. The northeast Aqaba complex represents one of the most significant regions in the South Jordan basement. The basement rocks in the studied region are composed of schists, gneisses, migmatites, met gabbros, diorite, and granite. It is invaded by post-orogenic dike swarms. The post-orogenic dike swarms have been recognized as felsic dikes of dacite, rhyodacite, and rhyolite composition. They are composed of plagioclase, K-feldspar, quartz, biotite, and hornblenble with a porphyritic texture. Chemically, they are enriched in compatible elements especially in the large ion lithophile elements such as K, Rb, and Ba. The values of A/NK are more than A/CNK, indicating that dacitic dike swarms have metaluminous nature. Meanwhile, the values of A/NK are less than A/CNK in rhyodacitic and rhyolitic dike swarms of prealuminous nature. This felsic dike can be related to an intercontinental setting that was accompanied by a chemical evolution of the extensional movements and is formed by partial melting of crustal rocks, which are already known from other areas in the northeast portion of the Arabian-Nubian Shield.     

Effects of biochar, cow bone, and eggshell on Pb availability to maize in contaminated soil irrigated with saline water

Toxicity of heavy metals adversely affects environment and human health. Organic materials derived from natural matters or wastes have been applied to soils to reduce the mobility of contaminants such as heavy metals. However, the application of cow bone powder (CB), biochar (BC), and eggshell powder (ES) is rarely investigated for the reduction of Pb bioavailability in soils irrigated with saline water. The objective of this study was to assess the effectiveness of CB, BC, and ES additions as immobilizing substances on Pb bioavailability in shooting range soil irrigated with deionized and saline water. Each additive of CB, BC, and ES at 5 % (w/w) was mixed with soils and then the deionized and saline water were irrigated for 21 days. With deionized water irrigation, the soils treated with CB, BC, and ES exhibited higher pH when compared with saline water irrigation. With saline water irrigation, the electrical conductivity, water-soluble anions, and cations were significantly increased in soils treated with CB, BC, and ES. The water-soluble Pb in soils treated with CB, BC, and ES was significantly decreased with saline water irrigation. On the other hand, the water-soluble Pb in soil treated with CB was increased with deionized water irrigation. Only BC with saline water irrigation decreased the Pb concentration in maize shoots.