Improvement of soft ground bearing capacity using synthetic meshes

This paper describes the primary ground improvement of hydraulic fill used in Japan prior to conventional deep ground treatment such as vertical drains. Use is made of a high density polyethylene mesh to form a sand mat over soft silty clay hydraulic fill dredged from the sea bed. Establishment of the sand mat is necessary to allow trafficking of the soft fill by construction plant. In this method the mesh is laid on the hydraulic fill either directly below or above the water level, following which sand is placed to the required thickness using sand pumps. Using this method of construction any pumping action in the hydraulic fill does not arise during trafficking by construction plant. Consideration is given to the principles involved and construction and testing techniques employed are reviewed.     

Restoration challenges for urban rivers.

Urban sources account for significant quantities of important diffuse pollutants, and urban watercourses are typically badly polluted. As well as toxic metals, hydrocarbons including PAHs, and suspended matter, priority urban pollutants include faecal pathogens and nutrients. Can urban watercourses be restored by sufficient reductions in pollution loads? Case studies in the UK and Sweden provide insights and some grounds for optimism. A major trans-Atlantic review of the performance of best management practices (BMPs) is informing BMP planning. New approaches such as the maximisation of self-purification capacity in the receiving waters may also need to be developed, alongside BMPs at source. Other initiatives in Europe, USA and China, including collaborative projects, are trying to address the intractable issues such as persistent pollutants from transport and urban infrastructure. The challenge is daunting, but there are clear ways forward and future research needs are evident.     

Correlations between calving ease and calf survival

Multitrait restricted maximum likelihood methods were used for estimation of heritabilities and genetic and phenotypic correlations between calving ease and calf survival. These analyses examined both direct and maternal effects. Genetic correlation for direct effects between calving ease and calf survival was approximately -.8 in both heifers and cows, indicating favorable associations, whereas phenotypic correlations were -.32 and -.22.     

Temperature resistance coefficient of composite resistive materials in the mixed-structure approximation

A method of calculating the temperature resistance coefficient and its temperature dependence for resistive materials in the approximation of a matrix-statistical structure is outlined.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 49, No. 3, pp. 477–481, September, 1985.     

Calendar maintenance of arbitrarily structured systems

A semi-Markov model is constructed that describes an arbitrarily structured multicomponent technological system and takes into account its calendar maintenance. Using an aggregation algorithm, approximate values of stationary reliability characteristics and an optimal term of maintenance work are determined for the system. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 69–86, March–April 2006.     

Flood risk mapping at European scale.

The aim of this article is to illustrate a framework for flood risk mapping at pan-European scale produced by the Weather-Driven Natural Hazards (WDNH) action of the EC-JRC-IES. Early results are presented in the form of flood risk index maps. We assess several flood risk factors that contribute to the occurrence of flood disasters. Among the causal factors of a flood disaster one is triggering a natural event in the form of extreme precipitation and consequently extreme river discharge and extreme flood water levels. The threatening natural event represents the hazard component in our assessment. Furthermore exposure and vulnerability are anthropogenic factors that contribute also to flood risk. In the proposed approach, flood risk is considered on the light of exposure, vulnerability and hazard. We use a methodology with a marked territorial approach for the assessment of the flood risk. Hence, based on mathematical calculations, risk is the product of hazard, exposure and vulnerability. Improvements on datasets availability and spatial scale are foreseen in the next phases of this study. This study is also a contribution to the discussion about the need for communication tools between the natural hazard scientific community and the political and decision making players in this field.     

Close interaction of coplanar circular cracks under shear loading

A new method is proposed for the stress analysis of an elastic space weakened by several arbitrarily located coplanar circular cracks subjected to an arbitrary shear loading. The method is based on a new type of integral equation and has definite advantages over the existing methods: equations are non-singular, the iteration procedure is rapidly convergent even for very close interactions. The method allows us to obtain a practically exact numerical solution to the problem of very close interactions. An accurate analytical solution is obtained for the case of two cracks, which are separated by a half of their radius or more. The stress intensity factors and the crack energy increase due to the interaction are computed for various distances between the cracks.The reported research was supported by a grant from the Natural Sciences and Engineering Research Council of Canada     

Phospholipid turnover in the liver mitochondria of rats on a diet with a varying fat and protein ratio

Using the method of pulse introduction of labeled precursors the authors studied metabolism of rat liver mitochondrial phospholipids. The animals received high-protein diets (36% protein) containing 20% (diet II) and 36% (diet III) of fat as compared with the control (I) diet (18% protein and 20% fat). It appeared that the increase of protein in the diet (diet II) led to a reduction in the efficacy of 14C-palmitic acid incorporation into mitochondrial phospholipids, to a fall in the rate of metabolism of mitochondrial phospholipids and to a rise of their half-life within mitochondrial membranes, with the half-life of phospholipids labeled with 14C-palmitic acid in the fatty acid part being increased to a far greater degree as compared with that of phospholipids labeled with 3H-glycerin in the polar part of the molecules. However, in the presence of a high protein quota in the diet the fat/protein ratio agreed with the control level (diet III), whereas the metabolism of mitochondrial phospholipids remained close to the control values.