Large-scale mantle discontinuity topography beneath Europe: Signature of akimotoite in subducting slabs

The mantle transition zone is delineated by seismic discontinuities around 410 and 660 km, which are generally related to mineral phase transitions. Study of the topography of the discontinuities further constrains which phase transitions play a role and, combined with their Clapeyron slopes, what temperature variations occur. Here we use P to S converted seismic waves or receiver functions to study the topography of the mantle seismic discontinuities beneath Europe and the effect of subducting and ponding slabs beneath southern Europe on these features. We combine roughly 28,000 of the highest quality receiver functions into a common conversion point stack. In the topography of the discontinuity around 660 km, we find broadscale depressions of 30 km beneath central Europe and around the Mediterranean. These depressions do not correlate with any topography on the discontinuity around 410 km. Explaining these strong depressions by purely thermal effects on the dissociation of ringwoodite to bridgmanite and periclase requires unrealistically large temperature reductions. Presence of several wt % water in ringwoodite leads to a deeper phase transition, but complementary observations, such as elevated Vp/Vs ratio, attenuation, and electrical conductivity, are not observed beneath central Europe. Our preferred hypothesis is the dissociation of ringwoodite into akimotoite and periclase in cold downwelling slabs at the bottom of the transition zone. The strongly negative Clapeyron slope predicted for the subsequent transition of akimotoite to bridgmanite explains the depression with a temperature reduction of 200–300 K and provides a mechanism to pond slabs in the first place.SC is funded by the Drapers’ Company Research Fellowship through Pembroke College, Cambridge, UK. AD was funded by the European Research Council under the European Community’s Seventh Framework Programme (FP7/20072013/ERC grant agreement 204995) and by a Philip Leverhulme Prize.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/2015JB012452 The data used are freely available from the IRIS (www.iris.edu) and ORFEUS (http://www.orfeus-eu.org) databases

Interactive design exploration for constrained meshes

In architectural design, surface shapes are commonly subject to geometric constraints imposed by material, fabrication or assembly. Rationalization algorithms can convert a freeform design into a form feasible for production, but often require design modifications that might not comply with the design intent. In addition, they only offer limited support for exploring alternative feasible shapes, due to the high complexity of the optimization algorithm. We address these shortcomings and present a computational framework for interactive shape exploration of discrete geometric structures in the context of freeform architectural design. Our method is formulated as a mesh optimization subject to shape constraints. Our formulation can enforce soft constraints and hard constraints at the same time, and handles equality constraints and inequality constraints in a unified way. We propose a novel numerical solver that splits the optimization into a sequence of simple subproblems that can be solved efficiently and accurately. Based on this algorithm, we develop a system that allows the user to explore designs satisfying geometric constraints. Our system offers full control over the exploration process, by providing direct access to the specification of the design space. At the same time, the complexity of the underlying optimization is hidden from the user, who communicates with the system through intuitive interfaces

Mécanismes de social engineering (phishing): étude technique et économique

Les escroqueries sur internet sont nombreuses et variées. Toute personne est susceptible d’être la cible d’une attaque lors d’une navigation sur le net. De plus en plus d’escrocs n’hésitent pas à recourir au Social Engineering comme levier pour acquérir des données sensibles de manière déloyale en exploitant les failles humaines. Le phishing est une technique de Social Engineering employée par ces pirates. Il est utilisé pour subtiliser des informations personnelles dans le but de commettre une usurpation d’identité à l’insu de leurs victimes. La force de persuasion de ces escrocs est la clé de voûte d’une attaque réussie. Le but de ce travail est tout d’abord d’explorer les différentes techniques de phishing utilisées par les pirates pour ensuite identifier les mesures de protection disponibles contre ce phénomène. Enfin, nous aborderons les moyens de lutte mis en œuvre par des organismes pour tenter de combattre ce fléau

Catalytic hydrogenolysis of lignin:The influence of minor units and saccharides

The precise elucidation of native lignin structures plays a vital role for the development of “lignin first” strategies such as reductive catalytic fractionation. The structure of lignin and composition of the starting material has a major impact on the product yield and distribution. Here, the differences in structure of lignin from birch, pine, reed, and walnut shell were investigated by combining detailed analysis of the whole cell wall material, residual enzyme lignin, and milled wood lignin. The results of the 2D heteronuclear single quantum coherence NMR analysis could be correlated to the product from Ru/C‐catalyzed hydrogenolysis if monomeric products from ferulate and p‐coumaryl and its analogous units were also appropriately considered. Notably, residual polysaccharide constituents seemed to influence the selectivity towards hydroxy‐containing monomers. The results reinforced the importance of adequate structural characterization and compositional analysis of the starting materials as well as distinct (dis)advantages of specific types of structural characterization and isolation methods for guiding valorization potential of different biomass feedstocks

A low attenuation layer in the Earth's uppermost inner core

The attenuation structure of the Earth's inner core, in combination with the velocity structure, provides much insight into its rheological and mineralogical properties. Here, we use a large data set of PKIKP/PKiKP amplitude ratios to derive attenuation models for the upper 100 km of the inner core, incorporating the effects of velocity models calculated using the same data set. We confirm that the upper inner core is hemispherical in attenuation, with stronger attenuation in the east hemisphere. We also observe, for the first time, a low attenuation upper layer of approximately 30 km thickness throughout the top of the inner core. Attenuation increases beneath this layer, and then gradually decreases going deeper into the inner core. Although the data appear to show attenuation anisotropy below 57.5 km depth in the west, we find that this can be explained by the velocity models alone, with no requirement for attenuation anisotropy in the upper inner core

Аналіз фінансово-економічних передумов створення фінансового кластеру в західному регіоні України

У статті проведено аналіз фінансового забезпечення суб’єктів підприємницької діяльності Західного регіону України, визначено основні проблеми цього регіону і можливості їх вирішення шляхом створення фінансового кластеру. Запропоновано модель фінансового кластеру регіону та виділено основних потенційних учасників об’єднання.В статье проведен анализ финансового обеспечения субъектов предпринимательской деятельности Западного региона Украины, определены основные проблемы региона и возможности их решения путем создания финансового кластера. Предложена модель финансового кластера региона и выделены основные потенциальные участники объединения.The financial support of entrepreneurs in the Western region of Ukraine is analyzed in the article. The main problems of the region are identified and are proposed the methods to solve them developing a financial cluster. The model of financial cluster is proposed and the basic participants of association are selected

Сіверський слід походження роду Мазеп

The seismic structure of Earth’s inner core is highly complex, displaying strong anisotropy and further regional variations. However, few seismic waves are sensitive to the inner core and fundamental questions regarding the origin of the observed seismic features remain unanswered. Thus, new techniques to observe different types of inner core waves are imperative to improve data coverage. Here, we detail our method for detecting exotic inner core phases such as PKJKP and PKIIKP, using inner core compressional waves as proof of concept. We use phase weighted stacking on long period data from a global distribution of stations, and employ several synthetic methods, including normal mode summation and SPECFEM, to identify and confirm the inner core phases. We present evidence for two observations of exotic inner core compressional waves, and apply the technique to a previously detected inner core shear wave. A possible new inner core shear wave remains unconfirmed. Additionally, we show how our method is important for rejecting potential observations, and distinguishing between waves with similar traveltime and slowness. The method is most successful for detecting exotic inner core compressional waves, and will provide a new approach for studying the compressional wave structures in the upper inner core

Observations of core‐mantle boundary Stoneley modes

Core‐mantle boundary (CMB) Stoneley modes represent a unique class of normal modes with extremely strong sensitivity to wave speed and density variations in the D” region. We measure splitting functions of eight CMB Stoneley modes using modal spectra from 93 events with M w > 7.4 between 1976 and 2011. The obtained splitting function maps correlate well with the predicted splitting calculated for S20RTS+Crust5.1 structure and the distribution of S diff and P diff travel time anomalies, suggesting that they are robust. We illustrate how our new CMB Stoneley mode splitting functions can be used to estimate density variations in the Earth's lowermost mantle. Key Points We present CMB Stoneley mode splitting function measurements The CMB Stoneley mode splitting correlates well with diffracted body wave data Our measurements allow to constrain density variations in the lowermost mantlePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99080/1/figS2_plot_prem_freq_Q_stoneley_paperrotated.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99080/2/grl50514.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99080/3/figS1_plot_coef_stoneley_paper_deg2_newrotated.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99080/4/README_suppl_mat_GRL.pd