Optimization of the osmotic drying process to abtain dry products of Tommy Atkins mango

Tropical fruits like mango (Mangifera indica L.), one of the most popular fruits of the world, although very much appreciated, is highly perishable and seguire special techniques for its conservation and commercialization. This work had as objective to optimize the process of osmotic drying of mango and to study the effect of the temperature, sucrose concentration and time of immersion on the loss of water and gain in solid content. The influence of each variable and its interactions on the response were analyzed through analysis of variance (F-test and determination coefficient). It was verified that the three factors show significant effect on the loss of water and gain of mango solids, within the limits of the study. The optimum condition found for dehydration used as pretreatment for larger loss of water and smaller gain of solids was: temperature of 50 ºC, concentration of 40% and immersion time of 90 min.Frutas tropicais como a manga (Mangifera indica L.) uma das mais populares do mundo, embora muito apreciadas, são altamente perecíveis e requer técnicas especiais para sua conservação e comercialização, razão por que se objetivou otimizar seu processo de secagem osmótica e estudar o efeito da temperatura, concentração de sacarose e tempo de imersão, em relação à perda de água e ganho de sólidos. A influência de cada variável e sua interação sobre as respostas, foram avaliada através da análise de variância (teste F e coeficiente de determinação). Verificou-se que os três fatores mostraram efeito significativo quanto à perda de água e ganho de sólidos de manga, dentro das faixas estudadas. A condição ótima encontrada para desidratação utilizada como pré-tratamento para maior perda de água e menor ganho de sólidos, foi temperatura de 50 ºC, concentração de 40% e tempo de imersão de 90 min.57658

Chaos in Anisotropic Pre-Inflationary Universes

We study the dynamics of anisotropic Bianchi type-IX models with matter and cosmological constant. The models can be thought as describing the role of anisotropy in the early stages of inflation. The concurrence of the cosmological constant and anisotropy are sufficient to produce a chaotic dynamics in the gravitational degrees of freedom, connected to the presence of a critical point of saddle-center type in the phase space of the system. The invariant character of chaos is guaranteed by the topology of the cylinders emanating from unstable periodic orbits in the neighborhood of the saddle-center. We discuss a possible mechanism for amplification of specific wavelengths of inhomogeneous fluctuations in the models. A geometrical interpretation is given for Wald's inequality in terms of invariant tori and their destruction by increasing values of the cosmological constant.Comment: 14 pages, figures available under request. submitted to Physical Review

Topological speckles

The time evolution of a topological Su-Schrieffer-Heeger chain is analyzed through the statistics of speckle patterns. The emergence of topological edge states dramatically affects the dynamical fluctuations of the wavefunction. The intensity statistics is found to be described by a family of noncentral chi-squared distributions, with the noncentrality parameter reflecting on the degree of edge-state localization. The response of the speckle contrast with respect to the dimerization of the chain is explored in detail as well as the role of chiral symmetry-breaking disorder, number of edge states, their energy gap, and the locations between which the transport occurs. In addition to providing a venue for speckle customization, our results appeal to the use of speckle patterns for characterization of nontrivial topological properties.Comment: 6 pages, 4 figure

Homoclinic chaos in the dynamics of a general Bianchi IX model

The dynamics of a general Bianchi IX model with three scale factors is examined. The matter content of the model is assumed to be comoving dust plus a positive cosmological constant. The model presents a critical point of saddle-center-center type in the finite region of phase space. This critical point engenders in the phase space dynamics the topology of stable and unstable four dimensional tubes $R \times S^3$, where $R$ is a saddle direction and $S^3$ is the manifold of unstable periodic orbits in the center-center sector. A general characteristic of the dynamical flow is an oscillatory mode about orbits of an invariant plane of the dynamics which contains the critical point and a Friedmann-Robertson-Walker (FRW) singularity. We show that a pair of tubes (one stable, one unstable) emerging from the neighborhood of the critical point towards the FRW singularity have homoclinic transversal crossings. The homoclinic intersection manifold has topology $R \times S^2$ and is constituted of homoclinic orbits which are bi-asymptotic to the $S^3$ center-center manifold. This is an invariant signature of chaos in the model, and produces chaotic sets in phase space. The model also presents an asymptotic DeSitter attractor at infinity and initial conditions sets are shown to have fractal basin boundaries connected to the escape into the DeSitter configuration (escape into inflation), characterizing the critical point as a chaotic scatterer.Comment: 11 pages, 6 ps figures. Accepted for publication in Phys. Rev.

Luminescent κ-Carrageenan-Based Electrolytes Containing Neodymium Triflate

In recent years, the synthesis of polymer electrolyte systems derived from biopolymers for the development of sustainable green electrochemical devices has attracted great attention. Here electrolytes based on the red seaweeds-derived polysaccharide κ-carrageenan (κ-Cg) doped with neodymium triflate (NdTrif3) and glycerol (Gly) were obtained by means of a simple, clean, fast, and low-cost procedure. The aim was to produce near-infrared (NIR)-emitting materials with improved thermal and mechanical properties, and enhanced ionic conductivity. Cg has a particular interest, due to the fact that it is a renewable, cost-effective natural polymer and has the ability of gelling in the presence of certain alkali- and alkaline-earth metal cations, being good candidates as host matrices for accommodating guest cations. The as-synthesised κ-Cg-based membranes are semi-crystalline, reveal essentially a homogeneous texture, and exhibit ionic conductivity values 1–2 orders of magnitude higher than those of the κ-Cg matrix. A maximum ionic conductivity was achieved for 50 wt.% Gly/κ-Cg and 20 wt.% NdTrif3/κ-Cg (1.03 × 10−4, 3.03 × 10−4, and 1.69 × 10−4 S cm−1 at 30, 60, and 97 °C, respectively). The NdTrif-based κ-Cg membranes are multi-wavelength emitters from the ultraviolet (UV)/visible to the NIR regions, due to the κ-Cg intrinsic emission and to Nd3+, 4F3/2→4I11/2-9/2.This research was funded by National Funds by Foundation for Science and Technology (FCT) and by FEDER funds through the POCI-COMPETE 2020 - Operational Programme Competitiveness and Internationalisation in Axis I - Strengthening research, technological development and innovation (FCOMP-01-0124-FEDER-037271, Pest-OE/QUI/UI0616/2014 and UID/CTM/50025/2013), projectLUMECD (POCI-01-0145-FEDER-016884 and PTDC/CTM-NAN/0956/2014), project UniRCell (SAICTPAC/0032/2015, POCI-01-0145-FEDER-016422)), and by the Portuguese National NMR Network (RNRMN). S. C. Nunes was funded by FCT projects (Post-PhD Fellowships of UniRCell and LUMECD projects). The R. F. P. Pereira was funded by FCT (SFRH/BPD/87759/2012 grant).info:eu-repo/semantics/publishedVersio

Tricritical Points in the Sherrington-Kirkpatrick Model in the Presence of Discrete Random Fields

The infinite-range-interaction Ising spin glass is considered in the presence of an external random magnetic field following a trimodal (three-peak) distribution. The model is studied through the replica method and phase diagrams are obtained within the replica-symmetry approximation. It is shown that the border of the ferromagnetic phase may present first-order phase transitions, as well as tricritical points at finite temperatures. Analogous to what happens for the Ising ferromagnet under a trimodal random field, it is verified that the first-order phase transitions are directly related to the dilution in the fields (represented by $p_{0}$). The ferromagnetic boundary at zero temperature also exhibits an interesting behavior: for $0<p_{0}<p_{0}^{*} \approx 0.30856$, a single tricritical point occurs, whereas if $p_{0}>p_{0}^{*}$ the critical frontier is completely continuous; however, for $p_{0}=p_{0}^{*}$, a fourth-order critical point appears. The stability analysis of the replica-symmetric solution is performed and the regions of validity of such a solution are identified; in particular, the Almeida-Thouless line in the plane field versus temperature is shown to depend on the weight $p_{0}$.Comment: 23pages, 7 ps figure

Theory of Functional Connections and Nelder-Mead optimization methods applied in satellite characterization

The growing population of man-made objects with the build up of mega-constellations not only increases the potential danger to all space vehicles and in-space infrastructures (including space observatories), but above all poses a serious threat to astronomy and dark skies. Monitoring of this population requires precise satellite characterization, which is is a challenging task that involves analyzing observational data such as position, velocity, and light curves using optimization methods. In this study, we propose and analyze the application of two optimization procedures to determine the parameters associated with the dynamics of a satellite: one based on the Theory of Functional Connections (TFC) and another one based on the Nelder-Mead heuristic optimization algorithm. The TFC performs linear functional interpolation to embed the constraints of the problem into a functional. In this paper, we propose to use this functional to analytically embed the observational data of a satellite into its equations of dynamics. After that, any solution will always satisfy the observational data. The second procedure proposed in this research takes advantage of the Nealder-Mead algorithm, that does not require the gradient of the objective function, as alternative solution. The accuracy, efficiency, and dependency on the initial guess of each method is investigated, analyzed, and compared for several dynamical models. These methods can be used to obtain the physical parameters of a satellite from available observational data and for space debris characterization contributing to follow-up monitoring activities in space and astronomical observatories.Comment: Submitted to Acta Astronautic

A cross-sectional study of the quality of life of patients living with type 1 diabetes treated with insulin glargine and neutral protamine hagedorn insulin and the implications

Objectives: The study aim was to identify key factors associated with the health-related quality of life (HRQOL) of patients with type 1 diabetes mellitus (T1DM) treated with neutral protamine Hagedorn (NPH) insulin or human insulin analog glargine (IGLA). Methods: We conducted two cross-sectional studies in Minas Gerais State, Brazil. One with 401 patients treated with IGLA, and the other with 179 T1DM patients treated with NPH. HRQOL was measured by Euroqol (EQ-5D-3L). Key findings: Most participants were male (51%), aged between 18 and 40 years (47%), non-black (58%) and from the highest economic strata (A1-B2) (74%). Participants perceived their health as good/very good (51%), had one to three medical consultations in the previous year (51%), were not hospitalized in the previous year (74%), did not report angina (96%), diabetic neuropathy (90%), hearing loss (94%) or kidney disease (89%). Non-severe hypoglycaemia episodes in the last 30 days were reported by 17% of participants. Conclusions: Higher HRQOL was associated with younger age (18-40 years), good/very good health self-perception, having had up to three medical consultations in the last year, not being hospitalized in the last year, having none to three comorbidities, not reporting angina, diabetic neuropathy, hearing loss or kidney disease and having had episodes of non-severe hypoglycaemia. In addition, the findings of our study demonstrated inequalities in access to treatment, which will be the subject of future research projects