Stabilized soil is, in general, a composite material that results from combination and optimization of properties in individual constituent materials. Well-established techniques of soil stabilization are often used to obtain geotechnical materials improved through the addition into soil of such cementing agents as Portland cement, lime, asphalt, etc. Replacement of natural soils, aggregates, and cement with solid industrial by-product is highly desirable. In some cases, a by-product is inferior to traditional earthen materials. Due to its lower cost, however, it makes an attractive alternative if adequate performance can be obtained. In other cases, a by-product may have attributes superior to those of traditional earthen materials. Often selected materials are added to industrial by-products to generate a material with well-controlled and superior properties.

Tropical shorelines are often occupied by stretches of mangrove forests. Despite the wide range of ecological and socio-economic benefits provided by mangrove ecosystem (Lewis, 2005; Bosire et al., 2008), over the past decades the mangrove hasbecomea plant in peril. The area of the world's mangrove forests has decreased by 35% during the last two decades of the 20th century (Valiela et al., 2001). Vast areas of mangrove forests have been cleared for urban development, industrialisation, agricultural land reclamation, timber and charcoal production and shrimp farming. Mangrove forests

One of the most important problems in the coastal areas all over the world is erosion which has threatened human activities in the areas exposed to such hazard. Coastline retreat could result in very serious economic, environmental, and social impacts depending on the eroded area.

No abstract

No abstract

No abstract

No abstract

Water-driven self-assembly of lipids displays a variety of liquid crystalline phases that are crucial for membrane functions. Herein, we characterize the temperature-induced phase transitions in two compositions of an aqueous self-assembly system of the octyl β-D-glucoside (βGlcOC(8)) system, using steady-state and time-resolved fluorescence measurements. The phase transitions hexagonal ↔ micellar and cubic ↔ lamellar were investigated using tryptophan (Trp) and two of its ester derivatives (Trp-C(4) and Trp-C(8)) to probe the polar headgroup region and pyrene to probe the hydrophobic tail region. The polarity of the headgroup region was estimated to be close to that of simple alcohols (methanol and ethanol) for all phases. The pyrene fluorescence indicates that the pyrene molecules are dispersed among the tails of the hydrophobic region, yet remain in close proximity to the polar head groups. Comparing the present results with our previously reported one for βMaltoOC(12), increasing the tail length of the hexagonal phase from C(8) to C(12) leads to less interaction with pyrene, which is attributed to the more random and wobbling motion of the longer alkyl tail. We measured a reduction (more hydrophobic) in the ratio of the vibronic peak intensities of pyrene (I(1)/I(3)) for the lamellar phase compared to that of the cubic phase. The higher polarity in the cubic phase can be correlated to the nature of its interface, which curves toward the bulk water. This geometry also explains the slight reduction in polarity of the headgroup region compared to the other phases. Upon the addition of Trp-C(8), the fluorescence lifetime of pyrene is reduced by 28% in the lamellar and cubic phases, whereas the I(1)/I(3) value is only slightly reduced. The results reflect the dominant role of dynamic interaction mechanism between the C(8) chain of Trp-C(8) and pyrene. This mechanism may be important for these two phases since they participate in the process of membrane fusion. Both lipid compositions show completely reversible temperature-induced phase transitions, reflecting the thermodynamic equilibrium structures of their mesophases. Probing both regions of the different lipid phases reveals a large degree of heterogeneity and flexibility of the lipid self-assembly. These properties are crucial for carrying out different biological functions such as the ability to accommodate various molecular sizes.