143 research outputs found
Análise Discriminante dos Sedimentos Superficiais de Fundo do Rio de la Plata e Plataforma Continental Adjacente
Foram aplicadas análises discriminantes sobre dados de sedimentos superficiais de fundo do Rio de la Plata e da plataforma continental interna adjacente. Os dados correspondem a 199 amostras previamente agrupadas, através da aplicação de análise de agrupamento hierárquico. Os sedimentos foram separados, para melhor interpretação e discriminação, em duas classes texturais: uma correspondente a sedimentos grosseiros (areias) e outra, a sedimentos finos (lamas). As equações usadas para o estudo dos sedimentos incluem a média, o desvio padrão, a assimetria e a curtose. Foi possível discriminar e caracterizar 5 grupos de sedimentos arenosos: areias mistas deltaicas (fluviais e marinhas rasas); areias marinhas rasas (transportadas em suspensão); areias da zona de surfe (transportadas em suspensão); areias de face de praia (transportadas por tração) e depósitos de areias cascalhosas (tempestitos). Os sedimentos lamosos foram discriminados em 4 grupos, com base na aplicação de 3 funções discriminantes, os quais são definidos pelas seguintes características: lamas arenosas (marinhas rasas); lamas (transportadas em tração e por correntes densas); lamas e areias muito finas (fluviais) e lamas deltaicas (marinhas rasas)
Classificação dos Sedimentos Superficiais de Fundo do Rio de la Plata e Plataforma Continental Adjacente através da Análise de Agrupamento
A aplicação da análise de agrupamento (Cluster Analysis) sobre os parâmetros estatísticos (média, mediana, desvio padrão, curtose, assimetria e primeiro percentil) correspondente aos sedimentos superficiais do fundo do Rio de la Plata e da plataforma continental interna adjacente permitiu observar a presença de três tipos diferentes de agrupamentos. Para o primeiro agrupamento, onde foram considerados os parâmetros estatísticos categorizados sem incluir a profundidade e com distância de corte do dendrograma dij = 10, foi possível distinguir cinco grupos de sedimentos diferentes: 1. lama arenosa; 2. areias; 3. cascalho arenoso; 4. lamas e lamas arenosas e 5. argila siltosa. No segundo agrupamento, além dos parâmetros estatísticos, foi também considerada a profundidade, obtendo-se a seguinte classificação dos sedimentos: 1. sedimentos de zonas costeiras até a isóbata de -20m; 2. sedimentos de zonas rasas entre -20 e -30m; 3. sedimentos de zonas intermediárias entre -30 e -55m; 4. sedimentos de plataforma interna entre -55 e -70m e 5. sedimentos transicionais em profundidades superiores a -70m. Para o terceiro agrupamento, foram utilizados somente os parâmetros estatísticos, diminuindo a distância do corte do dendrograma para dij = 5. Foram identificados 7 grupos: 1. siltes finos e argilas com areias; 2. areias finas lamosas; 3. areias médias ou grossas; 4. areias finas e muito finas; 5. cascalho arenoso; 6. siltes e 7. argila siltosa. A aplicação da análise de agrupamento hierárquico sobre os parâmetros texturais, sem considerar a profundidade, permitiram diferenciar os principais mecanismos deposicionais e de transporte que atuaram para gerar os depósitos dos sedimentos superficiais de fundo na área em estudo, bem como definir a presença dos mesmos, produzidos por processos diferentes dos atuais
Smeared phase transition in a three-dimensional Ising model with planar defects: Monte-Carlo simulations
We present results of large-scale Monte Carlo simulations for a
three-dimensional Ising model with short range interactions and planar defects,
i.e., disorder perfectly correlated in two dimensions. We show that the phase
transition in this system is smeared, i.e., there is no single critical
temperature, but different parts of the system order at different temperatures.
This is caused by effects similar to but stronger than Griffiths phenomena. In
an infinite-size sample there is an exponentially small but finite probability
to find an arbitrary large region devoid of impurities. Such a rare region can
develop true long-range order while the bulk system is still in the disordered
phase. We compute the thermodynamic magnetization and its finite-size effects,
the local magnetization, and the probability distribution of the ordering
temperatures for different samples. Our Monte-Carlo results are in good
agreement with a recent theory based on extremal statistics.Comment: 9 pages, 6 eps figures, final version as publishe
Multi-layered Ruthenium-modified Bond Coats for Thermal Barrier Coatings
Diffusional approaches for fabrication of multi-layered Ru-modified bond coats for thermal
barrier coatings have been developed via low activity chemical vapor deposition and high activity
pack aluminization. Both processes yield bond coats comprising two distinct B2 layers, based on
NiAl and RuAl, however, the position of these layers relative to the bond coat surface is reversed
when switching processes. The structural evolution of each coating at various stages of the
fabrication process has been and subsequent cyclic oxidation is presented, and the relevant
interdiffusion and phase equilibria issues in are discussed. Evaluation of the oxidation behavior of
these Ru-modified bond coat structures reveals that each B2 interlayer arrangement leads to the
formation of α-Al 2 O 3 TGO at 1100°C, but the durability of the TGO is somewhat different and in
need of further improvement in both cases
Rapid solubility and mineral storage of CO2 in basalt
The long-term security of geologic carbon storage is critical to its success and public acceptance. Much of the security risk associated with geological carbon storage stems from its buoyancy. Gaseous and supercritical CO2 are less dense than formation waters, providing a driving force for it to escape back to the surface. This buoyancy can be eliminated by the dissolution of CO2 into water prior to, or during its injection into the subsurface. The dissolution makes it possible to inject into fractured rocks and further enhance mineral storage of CO2 especially if injected into silicate rocks rich in divalent metal cations such as basalts and ultra-mafic rocks. We have demonstrated the dissolution of CO2 into water during its injection into basalt leading to its geologic solubility storage in less than five minutes and potential geologic mineral storage within few years after injection [1–3]. The storage potential of CO2 within basaltic rocks is enormous. All the carbon released from burning of all fossil fuel on Earth, 5000 GtC, can theoretically be stored in basaltic rocks [4]
Isothermal and Cyclic Aging of 310S Austenitic Stainless Steel
Unusual damage and high creep strain rates have been observed on components made of 310S stainless steel subjected to thermal cycles between room temperature and 1143 K (870 °C). Microstructural characterization of such components after service evidenced high contents in sigma phase which formed first from δ-ferrite and then from γ-austenite. To get some insight into this microstructural evolution, isothermal and cyclic aging of 310S stainless steel has been studied experimentally and discussed on the basis of numerical simulations. The higher contents of sigma phase observed after cyclic agings than after isothermal treatments are clearly associated with nucleation triggered by thermal cycling
A systematic review of how emotional self-awareness is defined and measured when comparing autistic and non-autistic groups
We would like to sincerely thank all the authors who shared their data with us. We would also like to thank Ira Lesser, Taylor Graeme, and Arvid Heiberg for kindly sharing their articles for the historical review. Review was conduced as part of CFH's PhD studies. We would like to thank the Northwood Trust, UK for their financial support for this research. Research data available upon request from first author.Peer reviewedPublisher PD
Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector
The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements
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