October 2006
Prediction of Early Strength of Concrete: A Fuzzy Inference System Model
The strength development in concrete with its age is essentially a constant volume solidification process, which is controlled by multivarious parameters. However, the concrete mixes are designed for 28 day’s target compressive strength. In a more general characterization, it can be said that increase in strength of concrete is achieved by decrease in water cement ratio and decrease in aggregate cement ratio....
October 2006
Mechanical behaviors of concrete combined with steel and synthetic macro-fibers
In this paper, hybrid fibers including high elastic modulus steel fiber and low elastic modulus synthetic macro-fiber (HPP) as two elements were used as reinforcement materials in concrete. The flexural toughness, flexural impact and fracture performance of the composites were investigated systematically. Flexural impact strength was analyzed with statistic analyses method; based on ASTM and JSCE method, an...
October 2006
Can we use the aa geomagnetic activity index to predict partially the variability in global mean temperatures?
Data for geomagnetic activity index aa and solar sunspot number Rz for 1868-2004 were subjected to correlation analysis with the global surface temperature (GST). The annual-means GT show that it had two warming phases and one cooling period. Observations of the Earth's near-surface temperature showed a global-mean temperature increase of approximately 1.1° C since 1877, occurred from 1887 to 1940 and...
October 2006
INS Study on Physical Mechanisms of Bioprotection
The present work is aimed to investigate by Inelastic Neutron Scattering the vibrational behaviour of a class of bioprotectant systems, such as homologous disaccharides, trehalose, maltose and sucrose, in water mixtures. The obtained neutron scattering findings point out that disaccharides, and in particular trehalose, have a destructuring effect on the water tetrahedral network, as emphasised by the analysis of the...
October 2006
Boundary compatibility condition and rotation in elasticity
The boundary compatibility condition in elasticity that was missed for more than one century has been formulated. The new condition has completed the Beltrami-Michell formulation in elasticity. The completed formulation can solve stress, displacement, and mixed boundary value problems. The boundary compatibility condition, which is not a rotation, should be imposed on an indeterminate boundary. The use of the new...
October 2006
Seismicity of the Carpathian region
Carpathian complex prognostic poligon has being created for testing of new methods and equipment and their implementation into the practice of seismotectonic investigations in the Transcarpathians. The polygon consists of a network of regime geophysical stations (RGS). I analyzed seismicity of the Ukrainian sector of the Carpathians. It is determined by local earthquakes and strong subcrustal earthquakes of the Vrancea...
October 2006
An Appraisal of The Abura Field
Petrophysical analysis was carried out for all the identified hydrocarbon intervals, from the four wells studied in the Abura Field using suites of geophysical well logs. From the analysis of the geological logs comprising gamma-ray, spontaneous potential, electrical resistivity, neutron and density logs, the total porosity in the hydrocarbon bearing zone was found to range from 18.0% to 28.0% and the water saturation...
October 2006
Mechanochemical route to synthesize Co3O4/CuO composite nanopowders
Co3O4/CuO composite nanopowders have been successfully synthesized by heating the precursor obtained via a mechanochemical reaction. The precursor and the nanopowders were characterized using thermogravimetric (TG), X-ray diffraction (XRD) and transmission electron spectroscopy (TEM). Subsequent thermal treatment of the precursor at 550-700 °C in air for 2 h resulted in the formation of Co3O4/CuO nanopowders with an...
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