Anomalies in a waterlike model confined between plates

Using molecular dynamic simulations we study a waterlike model confined between two fixed hydrophobic plates. The system is tested for density, diffusion and structural anomalous behavior and compared with the bulk results. Within the range of confining distances we had explored we observe that in the pressure-temperature phase diagram the temperature of maximum density (TMD line), the temperature of maximum and minimum diffusion occur at lower temperatures when compared with the bulk values. For distances between the two layers below a certain threshold ,$d\le d_c$, only two layers of particles are formed, for $d\ge d_c$ three or more layers are formed. In the case of three layers the central layer stays liquid while the contact layers crystallize. This result is in agreement with simulations for atomistic models

Tripartite Graph Clustering for Dynamic Sentiment Analysis on Social Media

The growing popularity of social media (e.g, Twitter) allows users to easily share information with each other and influence others by expressing their own sentiments on various subjects. In this work, we propose an unsupervised \emph{tri-clustering} framework, which analyzes both user-level and tweet-level sentiments through co-clustering of a tripartite graph. A compelling feature of the proposed framework is that the quality of sentiment clustering of tweets, users, and features can be mutually improved by joint clustering. We further investigate the evolution of user-level sentiments and latent feature vectors in an online framework and devise an efficient online algorithm to sequentially update the clustering of tweets, users and features with newly arrived data. The online framework not only provides better quality of both dynamic user-level and tweet-level sentiment analysis, but also improves the computational and storage efficiency. We verified the effectiveness and efficiency of the proposed approaches on the November 2012 California ballot Twitter data.Comment: A short version is in Proceeding of the 2014 ACM SIGMOD International Conference on Management of dat

Avaliação da dinâmica da água no solo e da evapotranspiração, trocas gasosas, estado hídrico e produção da videira.

NO VALE DO SUBMÉDIO SÃO FRANCISCO, OS CULTIVOS DE VIDEIRA DE VINHO SÃO IRRIGADOS DURANTE TODO O ANO. NESSE CULTIVO, A IRRIGAÇÃO COM DEFICIT É UTILIZADA PARA OBTER ALGUMAS CARACTERÍSTICAS DESEJÁVEIS NA UVA PARA A VINIFICAÇÃO. ASSIM, O OBJETIVO DESSE TRABALHO FOI AVALIAR OS EFEITOS DE ESTRATÉGIAS DE IRRIGAÇÃO COM DÉFICIT NA PRODUÇÃO DE UVAS DE VINHO EM PETROLINA - PE. O EXPERIMENTO FOI INSTALADO NA EMBRAPA SEMIÁRIDO. A VIDEIRA CV. SYRAH ENXERTADA SOBRE PAULSEN 1103 FOI PLANTADA EM 30 DE ABRIL DE 2009, NO ESPAÇAMENTO DE 1 M X 3 M, E IRRIGADA POR GOTEJAMENTO EM UM ARGISSOLO VERMELHO AMARELO EUTRÓFICO LATOSSÓLICO, TEXTURA MÉDIA. OS TRATAMENTOS DE MANEJO DE IRRIGAÇÃO FORAM: 1 - IRRIGAÇÃO PLENA (IP), SEM A RESTRIÇÃO DE ÁGUA ÀS VIDEIRAS DURANTE TODO O CICLO DE PRODUÇÃO; 2 - IRRIGAÇÃO COM DÉFICIT (ID), ONDE A APLICAÇÃO DE ÁGUA FOI INTERROMPIDA DESDE A FASE DE CACHO FECHADO ATÉ A COLHEITA; 3 - A IRRIGAÇÃO COM DEFICIT CONTROLADO (IDC), ONDE A APLICAÇÃO DE ÁGUA FOI INTERROMPIDA NA FASE DE CACHO FECHADO, COM IRRIGAÇÕES EVENTUAIS CONFORME O MONITORAMENTO DA UMIDADE DO SOLO. NO SÉTIMO CICLO DE PRODUÇÃO (7 DE MAIO DE 2014 A 3 DE SETEMBRO DE 2014 - 119 DIAS), OCORREU UMA PRECIPITAÇÃO TOTAL DE 15,5 MM, SENDO 10,7 MM APÓS A INTERRUPÇÃO DA IRRIGAÇÃO. OS VALORES MÉDIOS DE EVAPOTRANSPÍRAÇÃO DE REFERÊNCIA (ETO) E EVAPOTRANSPIRAÇÃO DA CULTURA (ETC) PARA O PERÍODO DE 119 DIAS FORAM DE 5,0 MM DIA-1 E 3,6 MM DIA-1, RESPECTIVAMENTE, ENQUANTO OS MAIORES VALORES FORAM DE 9,3 MM DIA-1 (115 DIAS APÓS A PODA DE PRODUÇÃO - DAPP, 30 DE AGOSTO DE 2014) E 7,4 MM DIA-1 (80 DAPP, 26 DE JULHO DE 2014). A LÂMINA BRUTA MÉDIA FOI DE 5,6 MM DIA-1 NO TRATAMENTO IP, PARA 83 DIAS DE IRRIGAÇÃO; 5,9 MM DIA-1 NO TRATAMENTO IDC, PARA 42 DIAS DE IRRIGAÇÃO, E 6,1 MM DIA-1 NO TRATAMENTO ID, EM 37 DIAS DE IRRIGAÇÃO. APÓS O INÍCIO DA INTERRUPÇÃO DA IRRIGAÇÃO NOS TRATAMENTOS ID E IDC, A REDUÇÃO DA UMIDADE DO SOLO OCORREU ATÉ A PROFUNDIDADES DE 0,6 M, EM DECORRÊNCIA DA MAIOR PRESENÇA DO SISTEMA RADICULAR DA CULTURA NESSA CAMADA DE SOLO. NAS PROFUNDIDADES DE 0,75 M A 1,0 M, AS VARIAÇÕES NOS VALORES DE UMIDADE FORAM MENORES. OS VALORES DE POTENCIAL HÍDRICO NA ANTEMANHÃ E AO MEIO-DIA. APRESENTARAM COMPORTAMENTO SIMILAR, COM MAIORES VALORES NAS PLANTAS DE IP E MENORES NAS PLANTAS DE IDC E ID. ENTRETANTO, AS PLANTAS EM IDC E ID NÃO APRESENTAVAM SINTOMAS DE PONTO DE MURCHA PERMANENTE DURANTE A AVALIAÇÃO DE ANTEMANHÃ. OS MENORES VALORES DE POTENCIAL HÍDRICO AO MEIO-DIA EM PLANTAS DE TODOS OS TRATAMENTOS ESTÃO RELACIONADOS COM OS VALORES DA TAXA DE TRANSPIRAÇÃO, OS QUAIS TENDEM A SEREM MAIORES NESTE HORÁRIO, UMA VEZ QUE AS PLANTAS ESTAVAM PERDENDO ÁGUA PARA A ATMOSFERA VIA TRANSPIRAÇÃO. HOUVE EFEITO DOS TRATAMENTOS NA MASSA TOTAL DE CACHOS, NÚMERO DE CACHOS POR PLANTA, MASSA DE CACHOS POR PLANTA E NA PRODUTIVIDADE, COM MAIORES VALORES NO TRATAMENTO IP, SEM DIFERENÇA ESTATÍSTICA PARA O TRATAMENTO IDC. QUANTO A MASSA MÉDIA DE CACHOS, O TRATAMENTO IP APRESENTOU MAIORES VALORES

Contamination of Cluster Radio Sources in the Measurement of the Thermal Sunyaev-Zel'dovich Angular Power Spectrum

We present a quantitative estimate of the confusion of cluster radio halos and galaxies in the measurement of the angular power spectrum of the thermal Sunyaev-Zel'dovich (SZ) effect. To achieve the goal, we use a purely analytic approach to both radio sources and dark matter of clusters by incorporating empirical models and observational facts together with some theoretical considerations. It is shown that the correction of cluster radio halos and galaxies to the measurement of the thermal SZ angular power spectrum is no more than 20% at $l>2000$ for observing frequencies $\nu>30$ GHz. This eliminates the concern that the SZ measurement may be seriously contaminated by the existence of cluster radio sources.Comment: 15 pages, 3 figures, accepted for publication in Ap

Coexistence Curve Singularities at Critical End Points

We report an extensive Monte Carlo study of critical end point behaviour in a symmetrical binary fluid mixture. On the basis of general scaling arguments, singular behaviour is predicted in the diameter of the liquid-gas coexistence curve as the critical end point is approached. The simulation results show clear evidence for this singularity, as well as confirming a previously predicted singularity in the coexistence chemical potential. Both singularities should be detectable experimentally.Comment: 9 pages Revtex, 3 figures. To appear in Phys. Rev. Let

The Sunyaev Zel'dovich effect: simulation and observation

The Sunyaev Zel'dovich effect (SZ effect) is a complete probe of ionized baryons, the majority of which are likely hiding in the intergalactic medium. We ran a $512^3$ $\Lambda$CDM simulation using a moving mesh hydro code to compute the statistics of the thermal and kinetic SZ effect such as the power spectra and measures of non-Gaussianity. The thermal SZ power spectrum has a very broad peak at multipole $l\sim 2000-10^4$ with temperature fluctuations $\Delta T \sim 15\mu$K. The power spectrum is consistent with available observations and suggests a high $\sigma_8\simeq 1.0$ and a possible role of non-gravitational heating. The non-Gaussianity is significant and increases the cosmic variance of the power spectrum by a factor of $\sim 5$ for $l<6000$. We explore optimal driftscan survey strategies for the AMIBA CMB interferometer and their dependence on cosmology. For SZ power spectrum estimation, we find that the optimal sky coverage for a 1000 hours of integration time is several hundred square degrees. One achieves an accuracy better than 40% in the SZ measurement of power spectrum and an accuracy better than 20% in the cross correlation with Sloan galaxies for $2000<l<5000$. For cluster searches, the optimal scan rate is around 280 hours per square degree with a cluster detection rate 1 every 7 hours, allowing for a false positive rate of 20% and better than 30% accuracy in the cluster SZ distribution function measurement.Comment: 34 pages, 20 figures. Submitted to ApJ. Simulation maps have been replaced by high resolution images. For higher resolution color images, please download from http://www.cita.utoronto.ca/~zhangpj/research/SZ/ We corrected a bug in our analysis. the SZ power spectrum decreases 50% and y parameter decrease 25

GHASP: an Hα\alpha kinematic survey of spiral galaxies - X. Surface photometry, decompositions and the Tully-Fisher relation in the Rc-band

We present Rc-band surface photometry for 170 of the 203 galaxies in GHASP, Gassendi H-Alpha survey of SPirals, a sample of late-type galaxies for which high-resolution Fabry-Perot H{\alpha} maps have previously been obtained. Our data set is constructed by new Rc-band observations taken at the Observatoire de Haute-Provence (OHP), supplemented with Sloan Digital Sky Survey (SDSS) archival data, obtained with the purpose of deriving homogeneous photometric profiles and parameters. Our results include Rc-band surface brightness profiles for 170 galaxies and $ugriz$ profiles for 108 of these objects. We catalogue several parameters of general interest for further reference, such as total magnitude, effective radius and isophotal parameters -- magnitude, position angle, ellipticity and inclination. We also perform a structural decomposition of the surface brightness profiles using a multi-component method in order to separate disks from bulges and bars, and to observe the main scaling relations involving luminosities, sizes and maximum velocities. We determine the Rc-band Tully Fisher relation using maximum velocities derived solely from H$\alpha$ rotation curves for a sample of 80 galaxies, resulting in a slope of $-8.1 \pm 0.5$, zero point of $-3.0 \pm 1.0$ and an estimated intrinsic scatter of $0.28 \pm 0.07$. We note that, different from the TF-relation in the near-infrared derived for the same sample, no change in the slope of the relation is seen at the low-mass end (for galaxies with $V_{max} < 125$ km/s). We suggest that this different behaviour of the Tully Fisher relation (with the optical relation being described by a single power-law while the near-infrared by two) may be caused by differences in the stellar mass to light ratio for galaxies with $V_{max} < 125$ km/s.Comment: 17 pages, 11 figure

Spin-phonon coupling in Gd(Co1/2Mn1/2)O3 perovskite

We have investigated the temperature-dependent Raman-active phonons and the magnetic properties of Gd(Co1/2Mn1/2)O3 perovskite ceramics in the temperature range from 40 K to 300 K. The samples crystallized in an orthorhombic distorted simple perovskite, whose symmetry belongs to the Pnma space group. The data reveals spin-phonon coupling near the ferromagnetic transition occurring at around 120 K. The correlation of the Raman and magnetization data suggests that the structural order influences the magnitude of the spin-phonon coupling.Comment: 3 Figures, suplementary materia