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971.
This paper presents the results of a comparative analysis of the socioeconomic impacts of the construction and operation of two nuclear generating stations. Although the construction of nuclear power plants is typically a multiyear process utilizing large numbers of workers and requiring large expenditures for equipment and materials, the socioeconomic changes in the areas in which the plants are located were small and temporary. The extent and size of the changes were found to be related to the size of the work force residing in the local area, the magnitude of local utility and contractor purchases, the amount of tax payments resulting from the plant, and the level of involvement of area groups over plant-related issues. 相似文献
972.
Analysis of the vajont slide — new approach 总被引:1,自引:0,他引:1
R. Chowdhury 《Rock Mechanics and Rock Engineering》1978,11(1):29-38
SummaryAnalysis of the Vajont Slide — New Approach This paper is concerned with the analysis of the 1963 Vajont slide in Italy. Attention is drawn to the fact that numerous investigations have been consistently unsuccessful in explaining the slide. A new approach consistent with a progressive failure mechanism established by all comprehensive investigations is suggested in this paper. The analysis simulates the transformation of the slope from a condition of stability to one of limit-equilibrium and failure in a step-by-step process. It is shown that the enormous velocities calculated on the basis of external observations of the slide can be explained by the new analytical approach.
Notation c unit effective cohesion - ø effective angle of shearing resistance (residual) - n proportion of the slip surface along which failure has progressed - K conjugate stress ratio for a slope - K 0 ratio of effective horizontal normal stress to effective vertical normal stress in the slope With 3 Figures 相似文献
ZusammenfassungAnalyse der Felsgleitung bei Vajont — Neuer Erklärungsversuch Dieser Artikel beschäftigt sich mit der Felsgleitung bei Vajont in Italien im Jahre 1963. Es wird darauf hingewiesen, daß es in einer Vielzahl anderer Untersuchungen bislang nicht möglich war, eine Erklärung für die Felsgleitung zu finden. Ein neues Modell, basierend auf dem Mechanismus des progressiven Zusammenbruchs wird vorgeschlagen. Die Untersuchung simuliert den Übergang des Hanges vom stabilen Zustand in ein Grenzgleichgewicht und schließlich den Zusammenbruch in einem Prozeß, der Schritt für Schritt abläuft. Es wird gezeigt, daß die enormen Geschwindigkeiten, die aufgrund von Beobachtungen berechnet wurden, im Rahmen dieses Modells erklärt werden können.
RésuméAnalyse de l'éboulement de Vajont — Nouvelle approche Cette communication constitue une analyse de l'éboulement de Vajont (Italie) en 1963. On souligne le fait que les nombreuses enquêtes entreprises pour expliquer cet éboulement se sont montrées infructueuses. Cette communication propose une nouvelle approche conforme à un mécanisme progressif de défaillances établi par toutes les enquêtes compréhensives. L'analyse simule la transformation graduelle de la pente: de la stabilité à l'équilibre limité et enfin à la défaillance. On démontre que les vélocités énormes calculées à base des observations externes de l'éboulement peuvent s'expliquer par cette nouvelle approche analytique.
Notation c unit effective cohesion - ø effective angle of shearing resistance (residual) - n proportion of the slip surface along which failure has progressed - K conjugate stress ratio for a slope - K 0 ratio of effective horizontal normal stress to effective vertical normal stress in the slope With 3 Figures 相似文献
973.
Definition of geochemical background in exploration and environmental geochemistry has always been regarded as contingent
upon scale and investigated locality but mostly under assumption that hosts of processes that produce the data more or less
conform individually to Gaussian law of “central tendencies”. Recently, understanding of pedogenesis as synergetic process
being characterized by non-linear dynamics renders thermodynamic approach directly applicable in assessment of geochemical
thresholds, with concepts of linearity and normality set alongside in solving the problems of soil geochemistry. Seen from
this perspective the work is an attempt to relate conceptual fundamentals of non-linear dynamical theory to basic statistical
methods in order to elucidate the nature and origins of element subpopulations hidden in the original geochemical data from
the soils of Istrian Peninsula (western Croatia). To this purpose the two major groups of soils were selected for analysis
depending on the type of bedrock as one of the main soil-forming factors. Geochemical data were subjected to the trimming
procedure by which the outliers were removed from the total data collective and attributed to non-linear causes precluding
simple cause-and-effect relationships as the sine qua non of Gaussian distribution. Geochemical background is then defined as the normal range of data of the remaining (trimmed) dataset
indicating the “thermodynamic branch” of the specific soil processes as opposed to outliers being described as dissipative
structures. 相似文献
974.
Debarati Mukherjee 《Journal of the Geological Society of India》2018,91(3):295-300
An improvized version of the conventional core drilling technique, based on a new device is introduced in the current work for extracting cores from fossil bones to understand their microanatomy. A powerful, low-speed electric drill with an autolubrication facility is used as the new device, and the bone specimen is placed on a permanently fixed platform beneath the drill bit. It avoids the vibration-induced wobbling of the conventional handheld drill machine and helps in precision sampling. Long drill bits of the new device result in extraction of long cores, reduce premature breakages of cores, and recovery of the entire bone microstructure for high resolution deduction of palaeobiological information. As this version of drilling technique is less destructive, it has better sampling coverage, where fossil bones can be restored to their original shapes and preserved with almost no loss in gross morphology. This is first time such a device for extraction of fossil drill cores has been installed. After test run on dummy samples, the new device has been successfully implemented for extraction of eleven cores from various long bones of the early Jurassic sauropod dinosaur Barapasaurus tagorei. The fossil bones are restored to their pre-coring shapes, the detail protocols of which are discussed here for the first time. 相似文献
975.
Ayesha Anjum Mousumi Das Jayant Murthy S. B. Gudennavar Rajesh Gopal S. G. Bubbly 《Journal of Astrophysics and Astronomy》2018,39(5):61
We have classified a sample of 37,492 objects from SDSS into QSOs, galaxies and stars using photometric data over five wave bands (u, g, r, i and z) and UV GALEX data over two wave bands (near-UV and far-UV) based on a template fitting method. The advantage of this method of classification is that it does not require any spectroscopic data and hence the objects for which spectroscopic data is not available can also be studied using this technique. In this study, we have found that our method is consistent by spectroscopic methods given that their UV information is available. Our study shows that the UV colours are especially important for separating quasars and stars, as well as spiral and starburst galaxies. Thus it is evident that the UV bands play a crucial role in the classification and characterization of astronomical objects that emit over a wide range of wavelengths, but especially for those that are bright at UV. We have achieved the efficiency of 89% for the QSOs, 63% for the galaxies and 84% for the stars. This classification is also found to be in agreement with the emission line diagnostic diagrams. 相似文献
976.
In this paper we present a new method of restoration of the true three-dimensional (3D) trajectories of prominence knots using
ground-based observations taken with a single telescope that is equipped with a Multi-Channel Subtractive Double Pass imaging
spectrograph. Our method allows us to evaluate the true 3D trajectories of the prominence knots without any assumptions concerning
the shape of the trajectories or the dynamics of the motion. The reconstructed trajectories of several knots observed in three
prominences are presented. 相似文献
977.
The current design of seismically isolated bridges usually combines the use of bearings and stoppers, as a second line of
defence. The stoppers allow the development of the in-service movements of the bridge deck, without transmitting significant
loads to the piers and their foundations, while during earthquake they transmit the entire seismic action. Despite the fact
that stoppers, which restrain the transverse seismic movements of the deck, are used frequently in seismically isolated bridges,
the use of longitudinal stoppers is relatively rare, mainly due to the large in-service constraint movements of bridges. The
present paper proposes a new type of external longitudinal stoppers, which are installed in stiff sub-structures-boundaries,
aiming at limiting the bridge seismic movements. The parametric investigation, which was conducted in order to identify the
seismic efficiency of the external stoppers, showed that the interaction of the bridge with the stiff boundaries can lead
to significant reductions in the seismic movements of the bridge. Serviceability is appropriately arranged in the paper by
expansion joints and approach slabs. 相似文献
978.
Recent Rapid Regional Climate Warming on the Antarctic Peninsula 总被引:15,自引:1,他引:15
David G. Vaughan Gareth J. Marshall William M. Connolley Claire Parkinson Robert Mulvaney Dominic A. Hodgson John C. King Carol J. Pudsey John Turner 《Climatic change》2003,60(3):243-274
The Intergovernmental Panel on Climate Change (IPCC) confirmed that mean global warming was 0.6 ± 0.2 °C during the 20th century and cited anthropogenic increases in greenhouse gases as the likely cause of temperature rise in the last 50 years. But this mean value conceals the substantial complexity of observed climate change, which is seasonally- and diurnally-biased, decadally-variable and geographically patchy. In particular, over the last 50 years three high-latitude areas have undergone recent rapid regional (RRR) warming, which was substantially more rapid than the global mean. However, each RRR warming occupies a different climatic regime and may have an entirely different underlying cause. We discuss the significance of RRR warming in one area, the Antarctic Peninsula. Here warming was much more rapid than in the rest of Antarctica where it was not significantly different to the global mean. We highlight climate proxies that appear to show that RRR warming on the Antarctic Peninsula is unprecedented over the last two millennia, and so unlikely to be a natural mode of variability. So while the station records do not indicate a ubiquitous polar amplification of global warming, the RRR warming on the Antarctic Peninsula might be a regional amplification of such warming. This, however, remains unproven since we cannot yet be sure what mechanism leads to such an amplification. We discuss several possible candidate mechanisms: changing oceanographic or changing atmospheric circulation, or a regional air-sea-ice feedback amplifying greenhouse warming. We can show that atmospheric warming and reduction in sea-ice duration coincide in a small area on the west of the Antarctic Peninsula, but here we cannot yet distinguish cause and effect. Thus for the present we cannot determine which process is the probable cause of RRR warming on the Antarctic Peninsula and until the mechanism initiating and sustaining the RRR warming is understood, and is convincingly reproduced in climate models, we lack a sound basis for predicting climate change in this region over the coming century. 相似文献
979.
In conventional seismic hazard analysis, uniform distribution over area and magnitude range is assumed for the evaluation of source seismicity which is not able to capture peculiar characteristic of near-fault ground motion well. For near-field hazard analysis, two important factors need to be considered: (1) rupture directivity effects and (2) occurrence of scenario characteristic ruptures in the nearby sources. This study proposed a simple framework to consider these two effects by modifying the predictions from the conventional ground motion model based on pulse occurrence probability and adjustment of the magnitude frequency distribution to account for the rupture characteristic of the fault. The results of proposed approach are compared with those of deterministic and probabilistic seismic hazard analyses. The results indicate that characteristic earthquake and directivity consideration both have significant effects on seismic hazard analysis estimates. The implemented approach leads to results close to deterministic seismic hazard analysis in the short period ranges (T < 1.0 s) and follows probabilistic seismic hazard analysis results in the long period ranges (T > 1.0 s). Finally, seismic hazard maps based on the proposed method could be developed and compared with other methods. 相似文献
980.
In a recent paper, Nof et al. (J Paleolimnol 35:417–439, 2006) suggest a physical mechanism which could account for the formation
of ice on Lake Kinneret (Sea of Galilee) in northern Israel. Based on the sea surface temperature record of sediment cores
from the Mediterranean Sea the authors argue that centennial-scale cold events had the potential to trigger local ‘springs
ice’ formation on the lake in the past. Here, we demonstrate that a closer inspection of the paleoceanographic record in combination
with correlation and regression analyses of meteorological data provides no evidence for such cold events in the lake region
during the last 10,000 years. Thus, the formation of ‘springs ice’ on Lake Kinneret was unlikely at least since the beginning
of the Neolithic. 相似文献