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1.
The paper pertains to the analysis of piles embedded in liquefiable soils to predict its’ critical buckling load under partial
to full loss of lateral support over a portion of the pile length. The analysis is based on extension of Mindlin solution
for a point load acting inside a semi infinite elastic half space. Degenerated solutions obtained by using the developed method
compares very well with reported results. Parametric studies showed that the depth of liquefiable soil, degradation of soil
strength on liquefaction, slenderness ratio, pile stiffness factor and end conditions have significant influence on the buckling
behavior of the piles. 相似文献
2.
The aim of this short note is to test whether the morphological skeletal network (MSN) of water bodies that resembles a river network follows Horton's laws. A fractal relationship of MSN of a water body is also shown. This investigation shows that the MSN of the Nizamsagar reservoir follows Horton's laws. Furthermore, this reservoir has a fractal dimension (D
m) of 1.92 which was computed by using two morphometric quantities and the fractal dimension of the main skeletal length (d). This value tallies exactly with the fractal dimension (D
f) of the whole MSN computed through box-counting method. 相似文献
3.
The aim of this short note is to test whether the morphological skeletal network (MSN) of water bodies that resembles a river network follows Horton's laws. A fractal relationship of MSN of a water body is also shown. This investigation shows that the MSN of the Nizamsagar reservoir follows Horton's laws. Furthermore, this reservoir has a fractal dimension (D m) of 1.92 which was computed by using two morphometric quantities and the fractal dimension of the main skeletal length (d). This value tallies exactly with the fractal dimension (D f) of the whole MSN computed through box-counting method. 相似文献
4.
This paper explores the personal narratives of 12 women members of the Heiveld, a rooibos1 producer cooperative in the Northern Cape province of South Africa. It contributes to the emerging literature in geography and allied disciplines on so-called ‘alternative economies’, the aims of which often include the conceptual re-location of agency from the capitalist system to the realm of the human. This work suggests that human development – both individual and collective – is central to the success and indeed the alterity of alternative economies. The Heiveld members’ narratives support these ideas, in particular through their accounts of the importance of autonomous work and the significance of learning from and with others. We argue, however, that these narratives also foreground a theme that tends to be neglected in the alternative economies literature – that of consumption and the possession of material things. Our interviewees repeatedly emphasise buying and owning things as being among the most meaningful outcomes of alternative economic activity. They see great value both in having their own money, homes, and furnishings, and in being able to give to others. Through an analysis of the reciprocal, meaningful relationships between these women and everyday objects, we suggest that consumption is not opposed to human development but can be part of it. More attention should therefore be paid to the ways in which tangible, material things help constitute the more commonly researched, intangible benefits of alternative economic participation, such as empowerment, dignity, knowledge-sharing and care for others. 相似文献
5.
6.
Estimates of core density deficit (cdd) of the Earth's outer core recently reported by Anderson and Isaak [Another look at the core density deficit of Earth's outer core, Phys. Earth Planet Int. 131 (2002) 19-27] are questionable in view of the serious errors in the pressure-volume and bulk modulus data due to an inadequacy in the calibration process used by Mao et al. [Static compression of iron to 300 GPa and Fe0.8Ni0.2 alloy to 200 GPa: implications for the core, J. Geophys. Res. 94 (1990) 21737-21742]. The data used by Anderson and Isaak deviate significantly from the corresponding values derived from seismology. In the present study we have used the input data on density, isothermal bulk modulus and its pressure derivative from Stacey and Davis [High pressure equations of state with application to lower mantle and core, Phys. Earth Planet Int. 142 (2004) 137-184] which are consistent with the seismological data. Volumes of hexagonal close-packed iron have been calculated at different temperatures under isobaric conditions at P = 330 GPa, the inner core boundary (ICB) pressure using the relationship between thermal pressure and volume expansion based on the lattice potential theory originally due to Born and Huang [Dynamical Theory of Crystal Lattices, Oxford University Press, Oxford, 1954, p. 50]. The formulation for thermal pressure used by Anderson and Isaak has been modified by taking into account the variations of thermal expansivity α and isothermal bulk modulus KT with temperature. Values of cdd are then estimated corresponding to different temperatures ranging from 4000 to 8000 K. The results for cdd at different temperatures obtained in the present study are significantly higher than those estimated by Anderson and Isaak suggesting that the cdd for the Earth's outer core is nearly 10%. The effects of nickel when an Fe-Ni alloy replaces Fe are estimated and found to be insignificant. 相似文献
7.
Application of the time-predictable model in Peninsular India for future seismic hazard assessment 总被引:1,自引:0,他引:1
It has been the belief among Earth scientists that the Peninsular Shield is aseismic, as the region attained stability long
ago. However, the earthquake at Koyna (10 December 1967), Bhadrachalam (13 April 1969), Broach (23 March 1970), Hyderabad
(30 June 1983), Khillari (30 September 1993), Jabalpur (22 May 1997), Gujarat (26 January 2001), and additional ones of smaller
magnitudes, altered this concept. This area has experienced many widely distributed shallow earthquakes, some of them having
large magnitudes. It is now widely accepted that seismic activity still continues with moderate events. Therefore, a need
has arisen to take into consideration recent seismological data to assess the future seismic status of Peninsular India. Earthquake
generation model has been studied to develop the statistical relations with surface wave magnitude (M
S
≥ 4.5). Five seismogenic sources showing clustering of earthquakes and including at least three main shocks of magnitude
4.5 ≤ M
S
≤ 6.5 giving two repeat times, have been identified. It is mainly based on the so-called “regional time-predictable model”.
For the considered region it is observed that the time interval between two consecutive main shocks depends on the preceding
main shock magnitude (M
p
) not on the following main shocks magnitude M
f
suggesting the validity of time predictable model in the region. 相似文献
8.
9.
Durga Shanker Mitra Ratheesh Ramakrishnan Harshvardhan Dave Subhobroto Mazumder 《国际地球制图》2013,28(5):404-419
An attempt has been made to use synthetic aperture radar (SAR) data for detection and monitoring of offshore oil seeps in the eastern offshore areas of the Krishna–Godavari Basin, which has been supplemented and correlated with collateral free-air gravity and seismic data. Images of the study area obtained from ENVISAT ASAR image mode were processed and analysed in detail. A number of natural oil seepages were identified and distinguished from pollution and biogenic slicks. These were subsequently studied using different parameters to assign various degrees of confidence. The repetitiveness of the identified seepages was studied and a total of five areas of seep repetitions had been recognized in the study area. The seeps that are repeated in images of different dates are more likely to be of natural origin than others. Simulation and modelling of a particular oil slick arising has been attempted over the Krishna–Godavari offshore using MIKE 21 software. 相似文献
10.
Mohd Sofiyan Sulaiman Shanker Kumar Sinnakaudan Nik Nuraini Azhari Roslan Zainal Abidin 《Environmental Earth Sciences》2017,76(7):300
Mountain rivers and lowland rivers differ in many ways. Some of the many elements that distinguish both river systems apart are the rivers’ geomorphological appearances, hydraulic geometry, pollution transport, sediment transport, and its own roughness and coarseness. In this particular study, the element of sediment transport is given distinctive attention too. This study employs the deterministic approach for bed load prediction entailing the use of the parameterization concept where particle size and flow variation is taken into full consideration. Apart from that, the classical approach of Shields number is also used to determine the transport rates at the fluvial system. However, due to some limitation and range of applicability, the Shields number approach was re-modified to suit the range of applicability. Changes were made to the alleviating critical stress term and formulating exponential approach. For this research, it was important to deduce the underlying principles which are universal and common to all river systems, due to obvious and distinct differences between the mountain and lowland rivers. A special attribute was given to the Malaysian natural rivers because of the limited recorded data available. All datasets were compiled and tested with the bed load predictors to observe the commonality pattern between the lowland and mountain river systems. Most of the bed load transport equations limit the range of applicability by isolating the flow regime or bed roughness individually. Thus, it was vital for researchers to find the commonality pattern between these two river systems which needed to be statistically sound in its form. It was postulated that the particle densimetric Froude number is graphically and statistically fit for both river systems. Hence, this predictor is used as it has a high potential to be included in the sediment transport parameterization for Malaysian natural rivers. 相似文献