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1.We show that the population ecology of the 9- to 10-year cyclic, broadleaf-defoliating winter moth (Operophtera brumata) and other early-season geometrids cannot be fully understood on a local scale unless population behaviour is known on a European scale. 2.Qualitative and quantitative data on O. brumata outbreaks were obtained from published sources and previously unpublished material provided by authors of this article. Data cover six decades from the 1950s to the first decade of twenty-first century and most European countries, giving new information fundamental for the understanding of the population ecology of O. brumata. 3.Analyses on epicentral, regional and continental scales show that in each decade, a wave of O. brumata outbreaks travelled across Europe. 4.On average, the waves moved unidirectionally ESE–WNW, that is, toward the Scandes and the Atlantic. When one wave reached the Atlantic coast after 9–10 years, the next one started in East Europe to travel the same c. 3000 km distance. 5.The average wave speed and wavelength was 330 km year-1 and 3135 km, respectively, the high speed being incongruous with sedentary geometrid populations. 6.A mapping of the wave of the 1990s revealed that this wave travelled in a straight E–W direction. It therefore passed the Scandes diagonally first in the north on its way westward. Within the frame of the Scandes, this caused the illusion that the wave moved N–S. In analogy, outbreaks described previously as moving S–N or occurring contemporaneously along the Scandes were probably the result of continental-scale waves meeting the Scandes obliquely from the south or in parallel. 7.In the steppe zone of eastern-most and south-east Europe, outbreaks of the winter moth did not participate in the waves. Here, broadleaved stands are small and widely separated. This makes the zone hostile to short-distance dispersal between O. brumata subpopulations and prevents synchronization within meta-populations. 8.We hypothesize that hostile boundary models, involving reciprocal host–herbivore–enemy reactions at the transition between the steppe and the broadleaved forest zones, offer the best explanation to the origin of outbreak waves. These results have theoretical and practical implications and indicate that multidisciplinary, continentally coordinated studies are essential for an understanding of the spatio-temporal behaviour of cyclic animal populations

International audience; Two electromagnetic models were used to simulate snow emission at L-band from in situ measurements of snow properties collected at Dome C in Antarctica. Two different approaches were used: one based on the radiative transfer theory, and the other on the wave approach. The Soil Moisture Ocean Salinity (SMOS) satellite observations performed at 1.4 GHz (21 cm) were used to check the validity of these models. Model results based on the wave approach were in good agreement with SMOS observations, particularly for incidence angles lower than 55 o. Comparisons suggest that the wave approach is more suitable to simulate brightness temperature at L-band than the transfer radiative theory, because interference between the layers of the snowpack is better taken into account. The model based on the wave approach was then used to investigate several L-band characteristics at Dome C. The emission e-folding depth, i.e. 67% of the signal, was estimated at 250 m, and 99% of signal emanated from the top 900 m. Lband brightness temperature is only slightly affected by seasonal variations in surface temperature, confirming the high temporal stability of snow emission at low frequency. Sensitivity tests showed that a good knowledge of density variability in snowpack is essential for accurate simulations in L-band.

Isaac Newton's reputation was initially established by his 1672 paper on the refraction of light through a prism; this is now seen as a ground-breaking account and the foundation of modern optics. In it, he claimed to refute Cartesian ideas of light modification by definitively demonstrating that the refrangibility of a ray is linked to its colour, hence arguing that colour is an intrinsic property of light and does not arise from passing through a medium. Newton's later significance as a world-famous scientific genius and the apparent confirmation of his experimental results have tended to obscure the realities of his reception at the time. This paper explores the rhetorical strategies Newton deployed to convince his audience that his conclusions were certain and unchallengeable. This commentary was written to celebrate the 350th anniversary of the journalPhilosophical Transactions of the Royal Society.

The present notes are written for the course in water wave mechanics given on the 7th semester of the education in civil engineering at Aalborg University. The prerequisites for the course are the course in fluid dynamics also given on the 7th semester and some basic mathematical and physical knowledge. The course is at the same time an introduction to the course in coastal hydraulics on the 8th semester. The notes cover the first four lectures of the course:• Definitions. Governing equations and boundary conditions.• Derivation of velocity potential for linear waves. Dispersion relationship Particle velocities and accelerations.• Particle paths, pressure variation, deep and shallow water waves, wave energy and group velocity.• Shoaling, refraction, diffraction and wave breaking.The last part of the course is on analysis of irregular waves and was included in the first two editions of the present note but is now covered by the note of Frigaard et al. (2012).The present notes are based on the following existing notes and books:• H.F.Burcharth: Bølgehydraulik, AaU (1991)• H.F.Burcharth og Torben Larsen: Noter i bølgehydraulik, AaU (1988).• Peter Frigaard and Tue Hald: Noter til kurset i bølgehydraulik, AaU (2004)• Ib A.Svendsen and Ivar G.Jonsson: Hydrodynamics of Coastal Regions, Den private ingeniørfond, DtU.(1989).• Leo H. Holthuijsen: Waves in ocean and coastal waters, Cambridge University Press (2007).

The numerical modeling and wave theory are used in tsunami mitigation analysis. It is assumed sea forest is simulating offshore structure submitted to wave loads. The sea forest acts simulate break waves in conservation of coastal territory and facility installed over there. The result reveal that mathematical modeling and numerical simulation can be used to understand tsunami ability in design and urban construction, the research indicates reduction of water deep by sea forest resulted in reducing geometry and all wave ability.

The need of a working infrastructure in a city also requires an understanding of how the traffic flows. It is known that increasing number of drivers prolong the travel time and has an environmental effect in larger cities. It also makes it more difficult for commuters and delivery firms to estimate their travel time. To estimate the traffic flow the traffic department can arrange cameras along popular roads and redirect the traffic, but this is a costly method and difficult to implement. Another approach is to apply theories from physics wave theory and mathematics to model the traffic flow; in this way it is less costly and possible to predict the traffic flow as well. This report studies the application of wave theory and expresses the traffic flow as a modified linear differential equation. First is an analytical solution derived to find a feasible solution. Then a numerical approach is done with Taylor expansions and Crank-Nicolson’s method. All is performed in Matlab and compared against measured values of speed and flow retrieved from Swedish traffic department over a 24 hours traffic day. The analysis is performed on a highway stretch outside Stockholm with no entries, exits or curves. By dividing the interval of the highway into shorter equal distances the modified linear traffic model is expressed in a system of equations. The comparison between actual values and calculated values of the traffic density is done with a nominal average difference. The results reveal that the numbers of intervals don’t improve the average difference. As for the small constant that is applied to make the linear model stable is higher than initially considered.

The paper provides a review of research results obtained by the author and colleagues in studying the fracture mechanisms of nano- and submicrocrystalline materials under various loading conditions. Fracture of material is considered in the context of Gibbs’ principles of nonequilibrium thermodynamics and is treated as its local structural phase decay. Nucleation of cracks is associated with initiation of micropores in high-curvature zones and their develop-ment proceeds by nonlinear wave mechanisms of opening mode cracking, dynamic rotations, and sliding or tearing mode cracking. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35259

Master's thesis in Offshore structural engineering This report looks into the possibility for using modified phased out shuttle tankers to install jacket foundations for offshore wind turbines. New massive wind mill farms are now being planned out in water depths of 40 meters and beyond, making the transition from monopoles to jacket type foundations inevitable. The similarity between these new foundations and the much larger jackets used on oil platforms, makes it natural to look into if the already well established technology can be applied to these foundations as well. A thorough dynamic analysis is carried out by the use of the computer program MOSES. Included in the analysis is a time domain analysis which will be compared to third party analyses. Further investigations of the non-linear behaviour are made to test the possibility for normalizing into a frequency domain solution. Also, based on these results, ways to reduce the dynamic amplification factors are examined. The main aspects are the lifting methods, the dynamic hook loads and the sea state limitations during installation.

The present notes are written for the course in water wave mechanics given on the 7th semester of the education in civil engineering at Aalborg University. The prerequisites for the course are the course in fluid dynamics also given on the 7th semester and some basic mathematical and physical knowledge. The course is at the same time an introduction to the course in coastal hydraulics on the 8th semester. The notes cover the following five lectures:1. Definitions. Governing equations and boundary conditions. Derivation of velocity potential for linear waves. Dispersion relationship. 2. Particle paths, velocities, accelerations, pressure variation, deep and shallow water waves, wave energy and group velocity.3. Shoaling, refraction, diffraction and wave breaking.4. Irregular waves. Time domain analysis of waves.5. Wave spectra. Frequency domain analysis of waves.The present notes are based on the following existing notes and books:H.F.Burcharth: Bolgehydraulik, AaU (1991)H.F.Burcharth og Torben Larsen: Noter i bolgehydraulik, AaU (1988).Peter Frigaard and Tue Hald: Noter til kurset i bolgehydraulik, AaU (2004)Zhou Liu and Peter Frigaard: Random Seas, AaU (1997)Ib A.Svendsen and Ivar G.Jonsson: Hydrodynamics of Coastal Regions, Den private ingeniorfond, DtU.(1989). Leo H. Holthuijsen: Waves in ocean and coastal waters, Cambridge University Press (2007).

O tratamento habitualmente dado em livros-texto de física à evolução da teoria ondulatória da luz, a partir do modelo de Christiaan Huygens, pode ser considerado uma reconstrução a posteriori (whiggismo), que impõe uma interpretação atual a conceitos enunciados no Século XVII. A leitura do texto original de Huygens, todavia, revela diferenças profundas com as concepções mais recentes da luz e uma afinidade maior com a mecânica do que com a óptica moderna ou o eletromagnetismo. Essa análise sugere a necessidade da utilização de fontes primárias no ensino de ciências, não se restringindo aos livros-texto que, muitas vezes, contêm uma leitura histórica cristalizada. Textbooks of Physics usually approach the evolution of the wave theory of light, from the model of Christiaan Huygens, as a reconstruction a posteriori (whiggism).This happens to impose the current interpretation to concepts already enunciated in the XVII century. However, the original texts of Huygens unveil important differences with the recent conceptions of light and a considerable affinity with Mechanics rather than with Modern Optics or Electromagnetism. Since the textbooks often contain a crystallized historical view, this analysis suggests the use of primary sources in the teaching of sciences.

This document gives several estimates on the design force, but only one estimate on the design wave climate.

O tratamento habitualmente dado em livros-texto de física à evolução da teoria ondulatória da luz, a partir do modelo de Christiaan Huygens, pode ser considerado uma reconstrução a posteriori (whiggismo), que impõe uma interpretação atual a conceitos enunciados no Século XVII. A leitura do texto original de Huygens, todavia, revela diferenças profundas com as concepções mais recentes da luz e uma afinidade maior com a mecânica do que com a óptica moderna ou o eletromagnetismo. Essa análise sugere a necessidade da utilização de fontes primárias no ensino de ciências, não se restringindo aos livros-texto que, muitas vezes, contêm uma leitura histórica cristalizada.