Solutions to Monge-Kantorovich equations, expressing optimality condition in mass transportation problem with cost equal to distance, are stationary points of a critical-slope model for sand surface evolution. Using a dual variational formulation of sand model, we compute both the optimal transport density and Kantorovich potential as t → ∞ limit of evolving sand flux and sand surface, respecti...

Most of the Tylenchulus semipenetrans larvae applied on the surface of four soils in pots 14.5-cm deep moved no further downward than 6.5 crn, and remained in the upper half of the pot. The percentage of second-stage larvae that developed into adult females on 'Homosassa' sweet orange in the soils were: sandy loam, 6.8% in the same soil with inoculation holes, 8.6%; loamy sand, 5.4%; coarse san...

BACKGROUND Leishmaniasis remains a global health problem because of the substantial holes that remain in our understanding of sand fly ecology and the failure of traditional vector control methods. The specific larval food source is unknown for all but a few sand fly species, and this is particularly true for the vectors of Leishmania parasites. We provide methods and materials that could be us...

Sand fields develop different patterns, such as sandbars, sand ridges, sand ripples, sand dunes, and river dunes. These vary in shape from crescent to ridge-like patterns. They are formed in areas such as deserts, lakes and seashores, where winds or fluid flows are strong and tend to blow from one direction or oscillate. There is a great deal of order in these patterns: perhaps a simple model c...

The western sand darter Ammocrypta clara, and eastern sand darter Ammocrypta pellucida, are sand-dwelling fishes of conservation concern. Past research has emphasized the importance of studying individual populations of conservation concern, while recent research has revealed the importance of incorporating landscape scale processes that structure habitat mosaics and local populations. We exami...

The clogging of infiltration basins is the main problem affecting proper functioning groundwater artificial recharge systems. In this study, several parameters have been varied to understand their impacts on water infiltration. experimental results show that effect initial humidity significant for less porous material such as silty soil (Hamri) and sand. air bubbles are also an important factor...

This research describes the goals, design and implementation of a quasi natural gradient, laboratory scale, sand tank (aquifer) model experiment. The model was used to study the transport of an inorganic tracer (Chloride) in groundwater, within a tropical aquifer (porous medium) material. Three-dimensional sand tank (1.8 m × 0.3 m × 0.8 m) experiments were conducted to investigate contaminant t...

Transmission lines located in the desert are subjected to desert climate, one of whose features is sandstorms. With long accumulation of sand and with the advent of moisture from rain, ambient humidity and dew, a conductive layer forms and the subsequent leakage current may lead to surface discharge, which may shorten the insulator life or lead to flashover thus interrupting the power supply. S...

The effect of irrigation with lake water containing a variety of microcystins on accumulation of toxins, or toxin metabolites, and plant growth in ryegrass, clover, rape, and lettuce, was investigated in a glasshouse experiment. The plants were grown in sand culture and received either three or six applications of lake water, which was applied either directly to the sand surface or to the plant...

Abstract When specimens of different sands are produced using the same preparation method and sheared under conditions (consolidation stress, loading, etc.), while simultaneously keeping drainage closed, resulting tendencies these regarding PWP build-up will be different. This research paper presents a simplified cyclic shear test, which is used to evaluate accumulation in defined specimen proc...