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Carl T. F. Ross Andrew P. F. Little Leonidas Chasapides Jeff Banks Daniele Attanasio 《Ocean Engineering》2004,31(2):239-252
The paper reports on the buckling of three ring-stiffened prolate domes under external hydrostatic pressure. The study was partly theoretical and partly experimental, where in the case of the latter, the finite element was used. Comparison between experiment and theory was good. The effect of ring stiffening the domes was to increase their buckling resistances by factors varying from 4.43 to 5.72. 相似文献
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Leonidas Slaucitajs 《Pure and Applied Geophysics》1956,35(1):40-48
Resumen Se exponen los resultados de cuatro campañas geomagnéticas llevadas a cabo entre 1951 y 1956 en la mencionada región del Antártico señalando el éxito obtenido mediante el uso del equipo instrumental compuesto por bien contrastados magnetómetros de QHM y BMZ en lugares de difícil acceso y condiciones severas. El campo medido se presenta con la existencia de muchas anomalías, a veces bastante fuertes, que se observan generalmente en las componentes de la intensidad. Es además notable el hecho de que los datos medidos directamente en la parte meridional extrema del Mar de Weddell, difieren de los que dan las cartas magnéticas mundiales extrapolados o calculados parcialmente en base a la teoría del potencial. Se confirma el rápido cambio secular en las intensidades, especialmente en la componente vertical, siendo en vez lento el cambio en la declinación. La situación de los puntos de observación y los resultados numéricos se dan en un mapa y una tabla de valores respectivamente.
Contribution del Instituto Antártico Argentino N 3. 相似文献
Summary This report covers four geomagnetic campaigns in the region of the Antarctic Peninsula, the adjacent islands and the Weddell Sea during the summer seasons of the years 1951 to 1956. The instrumental equipment was slightly modified to meet antarctic conditions in general, specially for transport to stations distant from the bases. In most antarctic points observations were made with both magnetometers QHM and BMZ which were compared at observatory and base stations by means of theodolite and earth inductor. The field measurements show the presence of many anomalies, some of which quite strong. The values observed in the southernmost area of the Weddell Sea differ appreciably from the figures given on world magnetic charts, which for some regions seem to be based on extrapolation or potencial computations. The secular change in declination is small but those in intensities are rapid, especially in the vertical component, confirming some previous indications. The results are tabulated and the position of the observation stations is shown on a map.
Contribution del Instituto Antártico Argentino N 3. 相似文献
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Leonidas T. Stavridis 《Geotechnical and Geological Engineering》2009,27(3):407-417
A rigid foundation of arbitrary shape resting on a stratified half space (soil), with specific geometrical and elastic properties
for its horizontal layers, is examined under the action of a vertical load placed anywhere on the foundation area. On the
basis of a purely analytical treatment of the deformability of the soil surface, i.e. without using a finite element discretization
of the layered soil mass, a general method is developed in order to determine the contact soil pressures and the resulting
settlements through an easily implemented numerical procedure. The possible presence of “inactive” foundation parts not being
in contact with the soil surface is taken into account. Parametric studies are performed showing the influence of the variability
of the soil layers, as well as of the vertical load location, on the contact pressures developed. In this context, for the
cases of a rectangular and a circular foundation the area borders for the location of a vertical load are determined, either
for the development of compressive soil pressures all over the footing (core), or for allowing the existence of some inactive
part without contact with the soil (zero contact pressure), not exceeding the half of the total foundation surface (limit
core). 相似文献
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Tomáš Galia Tereza Macurová Leonidas Vardakas Václav Škarpich Tereza Matušková Eleni Kalogianni 《地球表面变化过程与地形》2020,45(9):2048-2062
Although in-channel and floodplain large wood (LW) has been recognized as an important component of lotic ecosystems, there is still limited knowledge on the recruitment, mobility and retention of LW in rivers with an intermittent hydrological regime. In this study, we analysed the LW characteristics and related reach-scale variables of 22 reaches in a Mediterranean intermittent river (Evrotas, Greece) in order to identify predictors of in-channel and floodplain LW distribution. Our results indicated high downstream variation in LW volumes in the fluvial corridor (0.05–25.51 m3/ha for in-channel LW and 0–30.88 m3/ha for floodplain LW). In-channel and floodplain LW retention was primarily driven by the hydrological regime of the studied reaches (i.e. perennial or non-perennial) with higher volumes of LW observed in perennial sections. The width of the riparian corridor was an important predictor of LW storage at the reach scale. Non-perennial reaches had a disproportionally larger number of relatively small-diameter living trees at the expense of mature trees with larger diameters typical for riparian stands functioning as LW recruitment areas in perennial reaches. The smaller dimensions of in-channel LW in non-perennial reaches, coupled with the dominance of loose LW pieces, implies frequent LW transport during ordinary flood events. Nevertheless, overall low LW retention in the fluvial corridor under non-perennial flow regime predicts low volumes of mobilized LW. In contrast, the recruitment of relatively long and large-diameter LW from mature riparian stands in perennial reaches, together with additional LW stabilization by banks, bed sediments, living trees or other LW pieces decreases the potential for further LW transport. © 2020 John Wiley & Sons, Ltd. 相似文献
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Taufiq Hidayat Achmad Munir Budi Dermawan Anton Timur Jaelani Stéphane Léon Dading Hadi Nugroho Andriyan Bayu Suksmono Putra Mahasena Premana Wardayanti Premadi Dhani Herdiwijaya Chatief Kunjaya Zadrach Ledoufij Dupe Budi Brahmantyo Denny Mandey Muhammad Yusuf Hesti Retno Tri Wulandari Falahuddin Arief Muhammad Irfan Agus Triono Puri Jatmiko Evan Irawan Akbar Hery Leo Sianturi Jehunias Leonidas Tanesib Ali Warsito Judhistira Aria Utama 《Experimental Astronomy》2014,37(1):85-108
We report the first measurements of radio frequency spectrum occupancy performed at sites aimed to host the future radio astronomy observatory in Indonesia. The survey is intended to obtain the radio frequency interference (RFI) environment in a spectral range from low frequency 10 MHz up to 8 GHz. The measurements permit the identification of the spectral occupancy over those selected sites in reference to the allocated radio spectrum in Indonesia. The sites are in close proximity to Australia, the future host of Square Kilometre Array (SKA) at low frequency. Therefore, the survey was deliberately made to approximately adhere the SKA protocol for RFI measurements, but with lower sensitivity. The RFI environment at Bosscha Observatory in Lembang was also measured for comparison. Within the sensitivity limit of the measurement equipment, it is found that a location called Fatumonas in the surrounding of Mount Timau in West Timor has very low level of RFI, with a total spectrum occupancy in this measured frequency range being about 1 %, mostly found at low frequency below 20 MHz. More detailed measurements as well as a strategy for a radio quiet zone must be implemented in the near future. 相似文献
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