Development and analysis of a multi-node dynamic model for the simulation of stratified thermal energy storage

To overcome non-programmability issues that limit the market penetration of renewable energies, the use of thermal energy storage has become more and more significant in several applications where there is a need for decoupling between energy supply and demand. The aim of this paper is to present a multi-node physics-based model for the simulation of stratified thermal energy storage, which allows the required level of detail in temperature vertical distribution to be varied simply by choosing the number of nodes and their relative dimensions. Thanks to the chosen causality structure, this model can be implemented into a library of components for the dynamic simulation of smart energy systems. Hence, unlike most of the solutions proposed in the literature, thermal energy storage can be considered not only as a stand-alone component, but also as an important part of a more complex system. Moreover, the model behavior has been analyzed with reference to the experimental results from the literature. The results make it possible to conclude that the model is able to accurately predict the temperature distribution within a stratified storage tank typically used in a district heating network with limitations when dealing with small storage volumes and high flow rates

IAC 576 - cultivar de mandioca de mesa recomendada para Mato Grosso do Sul.

bitstream/item/24714/1/COT200380.pdfDocumento on-line

Calidad de vida de mujeres en fase de transición menopáusica evaluado por la menopause rating scale (MRS)

http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-75262010000600006&nrm=isoAntecedentes: En las últimas décadas han surgido cambios en la pirámide poblacional aumentando el número de mujeres en fase climatérica, esto unido al concepto de calidad de vida, le ha dado mayor relevancia al estudio de las modificaciones que ocurren en esta etapa de la vida. Objetivos: Identificar la frecuencia e intensidad de los síntomas de la transición menopáusica. Métodos: Estudio transversal comparativo en 969 mujeres de 45 a 64 años, usuarias de consultorios de Atención Primaria de Salud del Servicio de Salud Metropolitano Occidente, Santiago, Chile. Para evaluar la severidad de los síntomas climatéricos, se utilizó la Menopause Rating Scale (MRS). Para el análisis de los datos se utilizó el test T de Student, el test no paramétrico de Chi cuadrado, el test de Mann-Whitney y un nivel de significancia de 5%. Resultados: La edad promedio de las premenopáusicas fue de 49,1 ± 3,0 años y 55,3 ± 5,7 años en las posmenopáusicas. El síntoma más frecuente y que se presentó con mayor intensidad fueron las molestias musculares y articulares, el dominio más afectado fue el psicológico con una intensidad moderada y el perfil socio-demográfico fue similar para ambos grupos menopáusico. Conclusión: Al considerar el puntaje global de la escala MRS, ambos grupos se clasificaron en la categoría de intensidad moderada, pero en el grupo posmenopáusico, la puntuación fue más alta, lo que se traduce en una peor calidad de vida para estas mujeres, dado principalmente por el dominio psicológico. Background: There were changes in the recent decades in the population pyramid due an increase the number of women in climacteric phase, this antecedent, connected with the concept of quality of life, has given greater relevance to the study of the changes that occur in this stage of life. Objectives: To identify the frequency and intensity of the symptoms of the menopausal transition. Methods: A cross-sectional comparative population-based study was conducted. The selection of 969 women aged 45-64 years treated in the Primary Care Health Services of the Occident Region of Santiago, Chile. The Menopause Rating Scale was used to assess the severity of climacteric symptoms. Data were analyzed using the chi-squared test, T of Student test, the Mann-Whitney test; a probability of 0.05 was considered statistically significant. Results: The average age of premenopausal women were 49.1 ± 3.0 years and 55.3 ± 5.7 years in postmenopausal. The most frequent symptoms and of greater intensity was the muscle and joint discomfort, the domain most affected was the psychological with a moderate intensity and socio-demographic profile were similar for both menopausal groups. Conclusion: The global score of the MRS scale for both groups are classified in the category of moderate intensity, but in the postmenopausal group, the score was higher, resulting in a lower quality of life for these women, mainly due the psychological domain

Visible and near-infrared observations of asteroid 2012 DA14 during its closest approach of February 15, 2013

Near-Earth asteroid 2012 DA14 made its closest approach on February 15, 2013, when it passed at a distance of 27,700 km from the Earth's surface. It was the first time an asteroid of moderate size was predicted to approach that close to the Earth, becoming bright enough to permit a detailed study from ground-based telescopes. Asteroid 2012 DA14 was poorly characterized before its closest approach. We acquired data using several telescopes on four Spanish observatories: the 10.4m Gran Telescopio Canarias (GTC) and the 3.6m Telescopio Nazionale Galileo (TNG), both in the El Roque de los Muchachos Observatory (ORM, La Palma); the 2.2m CAHA telescope, in the Calar Alto Observatory (Almeria); the f/3 0.77m telescope in the La Hita Observatory (Toledo); and the f/8 1.5m telescope in the Sierra Nevada Observatory (OSN, Granada). We obtained visible and near-infrared color photometry, visible spectra and time-series photometry. Visible spectra together with color photometry of 2012 DA14 show that it can be classified as an L-type asteroid, a rare spectral type with a composition similar to that of carbonaceous chondrites. The time-series photometry provides a rotational period of 8.95 +- 0.08 hours after the closest approach, and there are indications that the object suffered a spin-up during this event. The large amplitude of the light curve suggests that the object is very elongated and irregular, with an equivalent diameter of around 18m. We obtain an absolute magnitude of H_R = 24.5 +- 0.2, corresponding to H_V = 25.0 +- 0.2. The GTC photometry also gives H_V = 25.29 +- 0.14. Both values agree with the value listed at the Minor Planet Center shortly after discovery. From the absolute photometry, together with some constraints on size and shape, we compute a geometric albedo of p_V = 0.44 +- 0.20, which is slightly above the range of albedos known for L-type asteroids (0.082 - 0.405).Comment: 7 pages, 4 figures, 1 table. Accepted in A&A (June 17 2013

Assessing the Potential of Intra-specific Biodiversity towards Adaptation of Irrigated and Rain-fed Italian Production Systems to Future Climate

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Testing the nature of S0 galaxies using planetary nebula kinematics in NGC 1023

We investigate the manner in which lenticular galaxies are formed by studying their stellar kinematics: an S0 formed from a fading spiral galaxy should display similar cold outer disc kinematics to its progenitor, while an S0 formed in a minor merger should be more dominated by random motions. In a pilot study to attempt to distinguish between these scenarios, we have measured the planetary nebula (PN) kinematics of the nearby S0 system NGC 1023. Using the Planetary Nebula Spectrograph, we have detected and measured the line-of-sight velocities of 204 candidate PNe in the field of this galaxy. Out to intermediate radii, the system displays the kinematics of a normal rotationally-supported disc system. After correction of its rotational velocities for asymmetric drift, the galaxy lies just below the spiral galaxy Tully-Fisher relation, as one would expect for a fading system. However, at larger radii the kinematics undergo a gradual but major transition to random motion with little rotation. This transition does not seem to reflect a change in the viewing geometry or the presence of a distinct halo component, since the number counts of PNe follow the same simple exponential decline as the stellar continuum with the same projected disc ellipticity out to large radii. The galaxy's small companion, NGC 1023A, does not seem to be large enough to have caused the observed modification either. This combination of properties would seem to indicate a complex evolutionary history in either the transition to form an S0 or in the past life of the spiral galaxy from which the S0 formed. More data sets of this type from both spirals and S0s are needed in order to definitively determine the relationship between these types of system.Comment: Accepted for publication in MNRAS. Version with full resolution figure 1 can be found at http://www.nottingham.ac.uk/~ppzmrm/N1023_PNS.accepted.pd

Emergence of Drug Tolerance in Cancer Cell Populations: An Evolutionary Outcome of Selection, Nongenetic Instability, and Stress-Induced Adaptation

In recent experiments on isogenetic cancer cell lines, it was observed that exposure to high doses of anticancer drugs can induce the emergence of a subpopulation of weakly proliferative and drug-tolerant cells, which display markers associated with stem cell-like cancer cells. After a period of time, some of the surviving cells were observed to change their phenotype to resume normal proliferation and eventually repopulate the sample. Furthermore, the drug-tolerant cells could be drug resensitized following drug washout. Here, we propose a theoretical mechanism for the transient emergence of such drug tolerance. In this framework, we formulate an individual-based model and an integro-differential equation model of reversible phenotypic evolution in a cell population exposed to cytotoxic drugs. The outcomes of both models suggest that nongenetic instability, stress-induced adaptation, selection, and the interplay between these mechanisms can push an actively proliferating cell population to transition into a weakly proliferative and drug-tolerant state. Hence, the cell population experiences much less stress in the presence of the drugs and, in the long run, reacquires a proliferative phenotype, due to phenotypic fluctuations and selection pressure. These mechanisms can also reverse epigenetic drug tolerance following drug washout. Our study highlights how the transient appearance of the weakly proliferative and drug-tolerant cells is related to the use of high-dose therapy. Furthermore, we show how stem-like characteristics can act to stabilize the transient, weakly proliferative, and drug-tolerant subpopulation for a longer time window. Finally, using our models as in silico laboratories, we propose new testable hypotheses that could help uncover general principles underlying the emergence of cancer drug tolerance

The outer halos of elliptical galaxies

Recent progress is summarized on the determination of the density distributions of stars and dark matter, stellar kinematics, and stellar population properties, in the extended, low surface brightness halo regions of elliptical galaxies. With integral field absorption spectroscopy and with planetary nebulae as tracers, velocity dispersion and rotation profiles have been followed to ~4 and ~5-8 effective radii, respectively, and in M87 to the outer edge at ~150 kpc. The results are generally consistent with the known dichotomy of elliptical galaxy types, but some galaxies show more complex rotation profiles in their halos and there is a higher incidence of misalignments, indicating triaxiality. Dynamical models have shown a range of slopes for the total mass profiles, and that the inner dark matter densities in ellipticals are higher than in spiral galaxies, indicating earlier assembly redshifts. Analysis of the hot X-ray emitting gas in X-ray bright ellipticals and comparison with dynamical mass determinations indicates that non-thermal components to the pressure may be important in the inner ~10 kpc, and that the properties of these systems are closely related to their group environments. First results on the outer halo stellar population properties do not yet give a clear picture. In the halo of one bright galaxy, lower [alpha/Fe] abundances indicate longer star formation histories pointing towards late accretion of the halo. This is consistent with independent evidence for on-going accretion, and suggests a connection to the observed size evolution of elliptical galaxies with redshift.Comment: 8 pages. Invited review to appear in the proceedings of "Galaxies and their Masks" eds. Block, D.L., Freeman, K.C. & Puerari, I., 2010, Springer (New York

Learning impact of education during pulmonary rehabilitation program. An observational short-term cohort study

Background: Among the several components integrating a pulmonary rehabilitation (PR) course, education may contribute to the individual\u2019s recognition of symptoms and worsening of the disease. However, the specific gain of education is far to be clearly documented to the health care providers. Aim of our preliminary study was to assess the learning impact of educational sessions (ES) in Chronic Obstructive Pulmonary Disease (COPD) patients referred to standard PR.Methods: Six ES on 3 areas (Symptoms-Therapies, Aids, Mood) were applied during PR at our clinic. The learning effect was prospectively evaluated by a specific questionnaire (ESQ) in 285 COPD patients (age 69\ub18 years, FEV1 53\ub114 % pred), then grouped into those who have completed ES (Completers group, n=226) or who did not (mean 2\ub11 ES) (Control group, n=59). Total and partial ESQ scores, and PR outcomes (6-minute walking test-6MWD, effort-dyspnoea at Medical Research Council scale-MRC, and health-related quality of life scale-SGRQ) were assessed in a pre (T0) to post (Tend) design.Results: Similar improvement in PR outcomes was recorded in both groups at Tend, whereas ESQ total and partial scores significantly increased in Completers only (p<0.001). ESQ-Aids score improved to a greater extent in Completers than in Control (+0.60\ub11.03 vs +0.27\ub11.27 point respectively, p=0.036). A higher proportion of Completers improved above the median change of both ESQ total and aids scores (p<0.05).Conclusion: Attending educational sessions produces a specific short-term learning effect during rehabilitation of COPD patients