Determination of Phosphate in Saudi Arabian Waters

The procedures for the determination of phosphate are based on the reduction of molybdophosphoric heteropoly acids using ascorbic acid. Measurements of the complex products formed with rhodamine B and chlorophenol red dyes and the reduced molybdophosphoric acid are made at 490 and 510 nm with molar absorptivities of 28571 and 20949 l/mol. cm with each dye, respectively. Phosphate could be determined in the concentration ranges of 0.44 to 1.21 and 0.44 to 1.32 μg/l PO₄-P with rhodamine B and chlorophenol red dyes, respectively. The results obtained are compared with those of molybdophosphoric acid with rhodamine B and chlorophenol red using stannous chloride as reducing agent. These procedures are used for the determination of phosphate in the Kingdom of Saudi Arabia.     

Soil deformation and shear strength characteristics of the Sana''a soil, Yemen Arab Republic

Deformation and strength characteristics of the soil of Sana'a, the Yemen Arab Republic, were investigated. Undisturbed soil samples were collected fro used in consolidation, collapse and strength tests. The classical and critical state compressibility parameters were determined using a one-dimensional collapsing potential of the investigated soil was determined by using both qualitative and quantitative analysis. Consolidated undrained triaxial tests different types of samples: saturated samples and samples at natural moisture content. The stress history of the fine soils are in the range of normal except for the stiff fissured lean clay which exhibited a relatively high overconsolidated stress history. The loess formations exhibited a moderate to under wetting and loading. The investigated soils are characterized by having high shear strength when they have low moisture content and a drastic dec content increases.     

The distribution and growth of urban settlements in Saudi Arabia

This paper examines the distribution characteristics of urban settlements in the Kingdom of Saudi Arabia through major dimensions such as settlement regularly, degree of primacy and polarisation at the national and geographic regional levels. The paper points out that the settlement pattern at the national level has transformed from a primate distribution during the pre-plan period (< 1970) to an intermediary distribution during the period of development planning (1970 >). At the geographical regional level the settlement distribution, however, has shown diverse pattern. While the regional settlement distribution of Western and Eastern Region have shown trends of increasing polarisation, settlements in the Northern and Southern Regions are more log-normal in character. This is explained by the increasing growth of small and intermediary towns in the Northern and Southern Regions. The paper concludes that the national trend of decreasing urban primacy, induced by the decentralised national development strategies, is less pronounced due to the absence of a balanced regional investment policy. Since the government expenditure and settlement population growth rates are not related, slow growing primate cities continue to receive a larger share of public expenditure, enabling them to retain their primacy. This calls for a balanced regional investment policy to fully realise the national strategy of regional balance and multi-polar settlement pattern.     

Isoprenoid alkanes with irregular “head-to-head” linkages

A lightly biodegraded crude oil from the Tolkinsk field (Upper Jurassic), situated in north-west Siberia, was found to contain a series of C₂₈–C₃₉ isoprenoid alkanes. Most of these components contain a pristane unit linked head-to-head with other isoprenoid units. The structures of these components were elucidated by mass spectral interpretations, comparisons with a synthesised standard and by reference to data published previously in the literature. These results extend the carbon number range, the variety of structural types, and the number of reported occurrences of these compounds in geological samples. These results provide further evidence for a contribution of bacterial cell-wall lipids to crude oils.     

The Korean Folk Custom Forbidding The Establishment of Water Wells

For over a thousand years many settlements in Korea forbid the digging of water‐wells. This custom can be explained using geomancy, which personifies local landscapes or names them after animate or inanimate objects. In ‘sailing boat’ landscapes the digging of water‐wells was prohibited because this was viewed as analogous to making a hole in the bottom of a boat, which would thus bring misfortune to local residents. Based on this geomantic reasoning, people considered the custom of forbidding well digging to be an integral part of the art of geomancy, with its origin in a geomantic belief system. My earlier research sustained this explanation but this paper, which is based on two recent instances of field work, rejects the established view on the custom. The aim of this paper is to critically re‐examine this established view and suggests a new idea that the folk custom of prohibiting well digging in Korea was not originally derived from geomancy, but was conceived from a non‐geomantic indigenous Korean idea and have become linked to geomancy through the enforcement process of practicing the custom in traditional Korean society.     

Porosity and size gradation of saturated gravel with percolated fines

Fine particles may infiltrate through coarse alluvial beds and eventually saturate the subsurface pore space. It is essential to understand the conditions that lead to bed saturation, and to forecast the packing characteristics of saturated beds to assess the effect of excess fine sediment supply on a number of processes that occur in the stream–sediment boundary. To address this problem, in this study, a new method is introduced to predict the grain‐size distribution for the saturated condition, and the resulting porosity decrease, given the characteristics of the bed and the supplied sediments. The new method consists of the numerical aggregation of infilling fines in a finite bed volume, during which the bed properties change to affect further infilling. An existing semi‐empirical, particle packing model is implemented to identify these properties. It is shown that these types of models are adequate to describe regimes of natural sediment fabric quantitatively, and are thus useful tools in the analysis of sediment infiltration processes. Unlike previous developments to quantify saturated bed conditions, which assume that the supplied material is uniform and finer than the bed pore openings, the method developed herein considers poorly sorted fines, and can identify size fractions that are able to ingress into the bed due to being smaller than the particles that form the bed structure. Application of the new method to published experimental data showed that the final content of infiltrated fines is strongly sensitive to the initial bed packing density, highlighting the need to measure and understand open‐work gravel deposits. In addition, the new method was shown to be suitable for assessing the degree of bed saturation, when it was applied to a published data set of field samples.