2,599 research outputs found
The Role of the Land Surface Background State in Climate Predictability
No full textSkill in ensemble-mean dynamical seasonal climate hindcasts with a coupled land-atmosphere model
and specified observed sea surface temperature is compared to that for long multi-decade integrations
of the same model where the initial conditions are far removed from the seasons of validation. The
evaluations are performed for surface temperature and compared among all seasons. Skill is found
to be higher in the seasonal simulations than the multi-decadal integrations except during boreal
winter. The higher skill is prominent even beyond the first month when the direct influence of the
atmospheric initial state elevates model skill. Skill is generally found to be lowest during the winter
season for the dynamical seasonal forecasts, equal to that of the long integrations, which show some
of the highest skill during winter. The reason for the differences in skill during the non-winter
months is attributed to the severe climate drift in the long simulations, manifest through errors in
downward fluxes of water and energy over land and evident in soil wetness. The drift presses the
land surface to extreme dry or wet states over much of the globe, into a range where there is little
sensitivity of evaporation to fluctuations in soil moisture. Thus, the land-atmosphere feedback is
suppressed, which appears to lessen the model’s ability to respond correctly over land to remote
ocean temperature anomalies.Center for Ocean-Land-Atmosphere StudiesPublishe
Simple drag prediction strategies for an Autonomous Underwater Vehicle’s hull shape
No full textThe range of an AUV is dictated by its finite energy source and minimising the energy consumption is required to maximise its endurance. One option to extend the endurance is by obtaining the optimum hydrodynamic hull shape with balancing the trade-off between computational cost and fluid dynamic fidelity. An AUV hull form has been optimised to obtain low resistance hull. Hydrodynamic optimisation of hull form has been carried out by employing five parametric geometry models with a streamlined constraint. Three Genetic Algorithm optimisation procedures are applied by three simple drag predictions which are based on the potential flow method. The results highlight the effectiveness of considering the proposed hull shape optimisation procedure for the early stage of AUV hull desig
THE CORRELATION OF THE MEDIEVAL EUROPEAN STATE AND LAW IN THE DOCTRINE OF P.A. KROPOTKIN
No full textThe actual task of Russian state studies and jurisprudence remains the opposition to the ideological and theoretical constructions of Russian classical anarchism. Purpose: to establish the most significant features and disadvantages of P.A. Kropotkin’s interpretation of the correlation of state and law on the example of Medieval Europe. When writing the article, the author applies interdisciplinary and class approaches. General scientific and specific scientific methods are used: historical, problem-theoretical, formal-logical, textual. Materials: monuments of law, other historical sources, foreign and national historiography. The analysis shows that P.A. Kropotkin’s works are characterised not only by a pronounced anti-exploitation pathos, but also by an equally pronounced tendentiousness. Results: aprioriism, anti-statism and antilegism, radical localism, Eurocentrism, diffusionism, cyclism and catastrophism, clothed in the form of postulates, predetermined P.A. Kropotkin’s one-sided interpretations of the interaction of the medieval European state with positive and customary law. In the first case, it took a purely causative form, and in the second, it was predominantly conflictual. These are the key flaws of P.A. Kropotkin’s correlation concept
Flow-induced gate vibrations: Prevention of sef-excitation computation of dynamic gate behaviour and the use of models
No full textThe objective of this study is to develop design criteria for the dynamic behaviour of gates and valves. To this end, a resume of existing theories is given as well as an extended analysis of the added water mass, hydrodynamic rigidity and damping (also negative damping or self-excitation) and excitation by turbulent flow. New computation methods are presented for self-exciting vibrations: The ensuing introduction of an instability indicator permits the prediction of such vibrations in the design phase. Methods are described to calculate the added water mass and water damping in flowing water. Also treated are the instability of overflowing and falling water nappes, the response of a mass-spring system to noise excitation by turbulence, and the technique of hydroelastic models. Prior publications by the author on these subjects are to be found in the Appendices.Hydraulic EngineeringCivil Engineering and Geoscience
Quality and qualities of design studies, design research and design
No full textGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Methodologie en Organisatie van Desig
Views of P.A. Krushevan on the National Problem in Russia: Moldavian or Russian Nationalist
No full textThe article deals with the national identity of P.A. Krushevan. Being of Moldavian nationality, he was a Russian conservative writer and journalist. At the beginning of the 19th century he served as a Russian nationalist in the political arena. The author shows that he was a supporter of Moldavian national traditions and a personality of the Moldavian national movement. At the same time Krushevan was an «imperial nationalist» and a Russian statesman. In behalf of Bessarabia peasants, he exposed the economic activity of «plutocracy», but he was a stranger to domestic anti-Semitism
Global intercomparison of 12 land surface heat flux estimates
No full textA global intercomparison of 12 monthly mean land surface heat flux products for the period 1993-1995 is presented. The intercomparison includes some of the first emerging global satellite-based products (developed at Paris Observatory, Max Planck Institute for Biogeochemistry, University of California Berkeley, University of Maryland, and Princeton University) and examples of fluxes produced by reanalyses (ERA-Interim, MERRA, NCEP-DOE) and off-line land surface models (GSWP-2, GLDAS CLM/Mosaic/Noah). An intercomparison of the global latent heat flux (Qle) annual means shows a spread of ∼20 W m -2 (all-product global average of ∼45 W m-2). A similar spread is observed for the sensible (Qh) and net radiative (Rn) fluxes. In general, the products correlate well with each other, helped by the large seasonal variability and common forcing data for some of the products. Expected spatial distributions related to the major climatic regimes and geographical features are reproduced by all products. Nevertheless, large Qle and Qh absolute differences are also observed. The fluxes were spatially averaged for 10 vegetation classes. The larger Q le differences were observed for the rain forest but, when normalized by mean fluxes, the differences were comparable to other classes. In general, the correlations between Qle and Rn were higher for the satellite-based products compared with the reanalyses and off-line models. The fluxes were also averaged for 10 selected basins. The seasonality was generally well captured by all products, but large differences in the flux partitioning were observed for some products and basins.</p
The Nigerian Co-operative Law: Taking the Baton from P.A. Oluyede
No full textSome of the challenges hindering the development of co-operatives and their governing laws in Nigeria are the inadequacy of literature, and the lack of standardized classification on the subject of co-operative law. With the aim to identify and espouse relevant literature on the subject matter, this paper seeks to collect, collate and review the relevant literature. A classic was identified in the work of P.A. Oluyede (1988) Nigeria Administrative Law, in chapter four, entitled “Public Corporations, and Public Enterprises.” Among other findings, the learned author dedicated the chapter to the historical development of Nigerian co-operative societies and their governing laws, situated cooperatives as public enterprises, and made recommendations. Furthermore, it was observed that there have been few contributions within the annals of the Nigerian academic and research community on co-operative law. Thus, Oluyede’s classics retains its position as a primary reference material for the modernization of the Nigerian cooperative law and sets the path for its standardization. However, supposedly consequential development has remained elusive, hence the imperatives to build on some of the positions espoused in Oluyede’s chapter in view of current realities. Although P.A Oluyede’s contribution retains its position as a top-notch reference material, some of the positions canvassed are no longer applicable to Nigerian co-operatives, hence the need to review Nigerian cooperative law as recommended. 
Sulphurised lipids in sediments: The key to reconstruct palaeobiochemicals and their origin
No full textApplied Science
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