White Dwarfs In Ngc6397 And M4: Constraints On The Physics Of Crystallization

We explore the physics of crystallization in the dense Coulomb plasma of the deep interiors of white dwarf stars using the color-magnitude diagram and luminosity function constructed from Hubble Space Telescope photometry of the globular cluster M 4 and compare it with our results for proper motion cleaned Hubble Space Telescope photometry of the globular cluster NGC 6397. We demonstrate that the data are consistent with a binary mixture of carbon and oxygen crystallizing at a value of Gamma higher than the theoretical value for a One Component Plasma (OCP). We show that this result is in line with the latest Molecular Dynamics simulations for binary mixtures of C/O. We discuss implications for future work.Astronom

Long-distance entanglement and quantum teleportation in XX spin chains

Isotropic XX models of one-dimensional spin-1/2 chains are investigated with the aim to elucidate the formal structure and the physical properties that allow these systems to act as channels for long-distance, high-fidelity quantum teleportation. We introduce two types of models: I) open, dimerized XX chains, and II) open XX chains with small end bonds. For both models we obtain the exact expressions for the end-to-end correlations and the scaling of the energy gap with the length of the chain. We determine the end-to-end concurrence and show that model I) supports true long-distance entanglement at zero temperature, while model II) supports {\it ``quasi long-distance''} entanglement that slowly falls off with the size of the chain. Due to the different scalings of the gaps, respectively exponential for model I) and algebraic in model II), we demonstrate that the latter allows for efficient qubit teleportation with high fidelity in sufficiently long chains even at moderately low temperatures.Comment: 9 pages, 6 figure

Impacts from the implementation of the ISO 22000

Purpose: The main purpose of this article is to assort different impacts of the ISO 22000 implementation considering internal or external impacts, positive or negative impacts. It also intends to provide a worldwide overview on the topic, to distinguish companies from different sectors and to gather different methodologies that are used in previously published articles related with this implementation. Design/methodology/approach- Different articles of the ISO 22000 implementation from different countries were gathered and singled out according to the information that was provided. The information of interest was analyzed and rewritten according to the initially established categories. Findings- The results from several studies, researches and points of view from different authors show that the ISO 22000 implementation carries positive impacts. Negative impacts are hard to find. Most of the impacts are directly related to the organizations themselves, hence being internal impacts. Studies are mainly carried out with the help of questionnaires that are presented to the companies. Research limitations/implications- The main goal was to come across different impacts and classify them either as positive and negative or internal and external. However, its unusual to find authors that consider negative impacts from the ISO 22000 implementation. Also, external impacts are not so common. Originality/value- This article mainly highlights the ISO 22000 implementation positive impacts in worldwide organizations. It summarizes the different countries views towards Food Safety Management Systems (FSMS) and how they affect the performance of their companies.U.Porto -Universidade do Porto(undefined)info:eu-repo/semantics/publishedVersio

Sistema de Controle da Pesca de Mato Grosso do Sul SCPESCA/MS - 9 - 2002.

Neste boletim encontram-se as informações sobre a pesca profissional e esportiva coletadas e analisadas pelo Sistema de Controle da Pesca de Mato Grosso do Sul (SCPESCA/MS), para o ano de 2002. Os dados obtidos foram provenientes do pescado capturado em toda a Bacia do Alto Paraguai em Mato Grosso do Sul e vistoriado pela Polícia Militar Ambiental/MS. Foi registrado um total de 686 t de pescado, do qual 312 t (45%) foram capturados pela pesca profissional e 374 t (55%) pela pesca esportiva. As espécies mais capturadas foram pintado Pseudoplatystoma corruscans (145 t, 27%), pacu Piaractus mesopotamicus (125 t, 24%), cachara Pseudoplatystoma fasciatum (54 t, 10%) e piavuçu Leporinus macrocephalus (41 t, 8%). Os rios que mais contribuíram foram Paraguai (253 t, 48%) e Miranda (125 t, 24%). Um total de 29.683 pescadores esportivos visitaram o Estado, provenientes, principalmente, de São Paulo (62%) com pico de ocorrência no mês de setembro. O número total de pescadores profissionais registrados foi de 1.272. Em mediana, mensalmente, os pescadores profissionais realizaram viagens com duração de 8 a 12 dias capturando entre 61,2 e 100,3 kg/pescador.viagem, com rendimento entre 7,35 e 13,22 kg/pescador.dia. Os pescadores esportivos, por sua vez, realizaram viagens com duração de 4 a 5 dias capturando entre 9,0 e 13,2 kg/pescador.viagem, com rendimento entre 2,12 e 2,97 kg/pescador.dia. De maneira geral, os dados de 2002 indicaram a mesma tendência observada nos anos anteriores em relação à diminuição na captura do dourado Salminus maxillosus pela pesca total, o que levou ao aumento do tamanho mínimo de captura para esta espécie, a vigorar a partir de 2004.bitstream/item/37403/1/BP47.pd

Effective Field Theory Approach to String Gas Cosmology

We derive the 4D low energy effective field theory for a closed string gas on a time dependent FRW background. We examine the solutions and find that although the Brandenberger-Vafa mechanism at late times no longer leads to radion stabilization, the radion rolls slowly enough that the scenario is still of interest. In particular, we find a simple example of the string inspired dark matter recently proposed by Gubser and Peebles.Comment: 19 pages, 2 figures, comments adde

Characterization of watermelon juice concentrated by reverse osmosis process.

Watermelon is a tropical fruit with excellent flavour, color, sweetness and succulence. Nowadays it is pointed out as an excellent source of lycopene, a carotenoid with antioxidant property. The objective of this work was to concentrate watermelon juice by reverse osmosis to obtain a concentrated product rich in lycopene. The juice was obtained by the depulping the fruits in a finisher with a 0.8 mm. Reverse osmosis was carried out in a pilot plant unit with composite membranes (conditioned in a plate and frame module. totalizing a permeate area of 0.72m2. The process was carried out at 30ºC, 60 bar and 650 L/h flow rate. Samples Lycopene content was determined by extraction with hexane measured in spectrophotometer at 503 nm. Antioxidant capacity s was evaluated by extraction with hexane followed by the quantification using ABTS as radical and Trolox as standard. The color loss was determined in spectrophotometer at 734nm after 15 min of reaction of the sample with the ABTS. The mean permeate flux was 22L1h1m

Finite-size scaling of the quasiespecies model

We use finite-size scaling to investigate the critical behavior of the quasiespecies model of molecular evolution in the single-sharp-peak replication landscape. This model exhibits a sharp threshold phenomenon at Q=Q_c=1/a, where Q is the probability of exact replication of a molecule of length L and a is the selective advantage of the master string. We investigate the sharpness of the threshold and find that its characteristic persist across a range of Q of order L^(-1) about Q_c. Furthermore, using the data collapsing method we show that the normalized mean Hamming distance between the master string and the entire population, as well as the properly scaled fluctuations around this mean value, follow universal forms in the critical region.Comment: 8 pages,tex. Submitted to Physical Review

Poynting's theorem and energy conservation in the propagation of light in bounded media

Starting from the Maxwell-Lorentz equations, Poynting's theorem is reconsidered. The energy flux vector is introduced as S_e=(E x B)/mu_0 instead of E x H, because only by this choice the energy dissipation can be related to the balance of the kinetic energy of the matter subsystem. Conservation of the total energy as the sum of kinetic and electromagnetic energy follows. In our discussion, media and their microscopic nature are represented exactly by their susceptibility functions, which do not necessarily have to be known. On this footing, it can be shown that energy conservation in the propagation of light through bounded media is ensured by Maxwell's boundary conditions alone, even for some frequently used approximations. This is demonstrated for approaches using additional boundary conditions and the dielectric approximation in detail, the latter of which suspected to violate energy conservation for decades.Comment: 5 pages, RevTeX4, changes: complete rewrit