Exergy analysis of a PWR core heat transfer

The exergetic analysis, a methodology of thermodynamics that quantifies of energy losses associated with irreversibility, allows to optimize the efficiencies of the various stages of a transformation process and thus its overall efficiency. In this contribution, a novel approach to the exergetic analysis is applied to the energy transformations taking place within the core of a nuclear reactor. To perform such analysis, reference was made to a pressurized light-water reactor (PWR), modeling the heat exchanges between the fuel assemblies and the coolant fluid in the core through the balance of incoming and outgoing mass and energy flows, incoming and outgoing the reactor. The results of the analysis are validated through a comparison with the actual reactor operating parameters. The main goals of the work –part of a wider ongoing research effort- are to develop the thermo-economic analysis of a PWR nuclear power plant (NPP) to assess the actual cost of the products obtainable downstream of the NPP (electric energy and thermal energy for industrial and civil users, very different products in terms of exergy contents), and to compare with the costs of similar products obtained from conventional thermal power plants

The Superficial Venous System: Art and Anatomy in Michelangelo’s Works

The Renaissance period was a laboratory of extensive scientific and artistic production that also included the study of the human body for both medical and artistic purpose. The artists of this period, especially those of the Italian schools, were particularly fascinated by human dissection and began to attend or perform public human dissections or public lessons of anatomy. They paid particular attention on superficial anatomy, especially on muscles, to understand body dynamics, but only a few of them focused on other neglected subcutaneous structures (veins, nerves, lymph nodes). Michelangelo Buonarroti (1475-1564), one of the most brilliant artists in Italian High Renaissance, had a wide knowledge in human anatomy coming from his experience in public dissection, when he joined to the court of Lorenzo de’ Medici, and later in life thanks to the friendship with the anatomist Realdo Colombo. The present article aimed to examine Michelangelo’s works, following a chronological order, to find the presence of subcutaneous veins. When represented, the anatomical correctness of the superficial venous network has been evaluated in marble sculptures and frescoes of the Sistine Chapel. Interesting anatomical considerations arose from the analysis of his famous works, in particular Pietà and David. Michelangelo paid a particular attention to anatomical dissection, this research being finalized to achieve detailed information for artistic purposes. The representation of distended superficial veins also contributed to transmit additional physical effort and emotional states in his masterpieces

The platelet-derived growth factor receptor alpha promoter-directed expression of cre recombinase in mouse placenta.

BackgroundNumerous pathologies of pregnancy originate from placental dysfunction. It is essential to understand the functions of key genes in the placenta in order to discern the etiology of placental pathologies. A paucity of animal models that allow conditional and inducible expression of a target gene in the placenta is a major limitation for studying placental development and function.ResultsTo study the platelet-derived growth factor receptor alpha (PDGFRα)-directed and tamoxifen-induced Cre recombinase expression in the placenta, PDGFRα-CreER mice were crossed with mT/mG dual-fluorescent reporter mice. The expression of endogenous membrane-localized enhanced green fluorescent protein (mEGFP) and/or dTomato in the placenta was examined to identify PDGFRα promoter-directed Cre expression. Pregnant PDGFRα-CreER;mT/mG mice were treated with tamoxifen at various gestational ages. Upon tamoxifen treatment, reporter protein mEGFP was observed in the junctional zone (JZ) and chorionic plate (CP). Furthermore, a single dose of tamoxifen was sufficient to induce the recombination.ConclusionsPDGFRα-CreER expression is restricted to the JZ and CP of mouse placentas. PDGFRα-CreER mice provide a useful tool to conditionally knock out or overexpress a target gene in these regions of the mouse placenta

Desenvolvimento inicial e estado nutricional do maracujazeiro em resposta à aplicação de lodo têxtil

In the treatment of liquid effluents of the textile industry the textile sludge results as residue. This work aimed at evaluating the effect of sludge application to the substrate of production of passion fruit cuttings in the development, and nutritional status of plants. Experimental design used was randomized blocks with five treatments and four replications. The textile sludge was applied in the doses of 10, 15, 20 and 30 g per pot (dry base), corresponding 10, 15, 20 and 30 t ha-1, respectively, and a control without application. Plants were fertilized with N, P, K, Zn and B at 300, 450, 150, 5, and 0.5 mg dm-3, respectively. The experimental unit was represented by pots with 2 dm3 of a Red Latosol (Oxisol) (V = 29%). After 100 days the textile sludge corrected soil acidity. However, in doses superior to 10 t ha-1 it caused plants death. The textile sludge increased the content of N, K, S, B, Mn and Zn, reduced Ca and Mg content, and it didn't alter Cu and Fe content of passion cuttings dry matter.O processo de tratamento de efluentes líquidos da indústria têxtil gera, como resíduo, um lodo de características orgânicas com concentração significativa de sódio e potássio. Objetivou-se quantificar os efeitos da aplicação do lodo ao solo, sobre o desenvolvimento inicial do maracujazeiro, e avaliou-se o crescimento e o estado nutricional das plantas. O delineamento experimental foi em blocos ao acaso, com quatro repetições de cinco tratamentos, que consistiram na aplicação de lodo têxtil, nas doses de 10, 15, 20 e 30 g vaso-1 (base seca), correspondentes a 10, 15, 20 e 30 t ha-1, respectivamente, além da testemunha sem aplicação do resíduo. As mudas receberam adubação básica com N, P, K, Zn e B, nas doses de 300, 450, 150, 5, e 0,5 mg dm-3, respectivamente. A unidade experimental foi constituída por vasos com 2 dm3 de amostra de um Latossolo Vermelho distrófico (V = 29%). Após 100 dias da semeadura, o lodo têxtil corrigiu a acidez do solo. Entretanto, em doses superiores a 10 t ha-1, promoveu a morte das plantas. O lodo têxtil aumentou os teores de N, K, S, B, Mn e Zn, diminuiu os de Ca e Mg e não alterou os de Cu e Fe da parte aérea das mudas

Calagem na nutrição de cálcio e no desenvolvimento do sistema radicular da goiabeira

The application of lime in acid soils improves the plant root system and, consequently, enhances water and nutrients absorption by the plants. The objective of this work was to evaluate the effects of lime application on the development of root system and calcium nutrition of guava plants cultivated in an acid distrofic Red Latosol (Typic Hapludox). Soil samples were collected in four equidistant points, at 75 cm of the trunk and at 0–20 cm and 20–40 cm of depth, in the plots that had received zero (control), 3.7 and 7.4 t ha-1 of lime. Soil samples were chemically analysed. Lime material was applied at planting, incorporated with grating and moldboard plow. On the second and third years after guava plantation, effects of liming in chemical properties were determined. Forty two months after lime incorporation in the soil (third year of guava plants cultivation), samples of roots were collected with a cylindrical auger, for dry mass and calcium content evaluation. Samples of leaves were also collected. Liming corrected soil acidity increased base saturation and improved calcium availability to plants and, consequently, improved guava root system. Calcium concentrations of 30 mmolc dm-3 in the soil and of 7.5 g kg-1 in the roots were associated with the highest guava root growth.A aplicação de calcário em solos ácidos promove maior desenvolvimento do sistema radicular das plantas e consequentemente, melhora a absorção de água e nutrientes. O objetivo deste trabalho foi avaliar os efeitos da aplicação de calcário no solo, no desenvolvimento do sistema radicular e na nutrição de cálcio de goiabeiras cultivadas em um Latossolo Vermelho distrófico ácido. Analisaram-se amostras de solo coletadas em quatro pontos eqüidistantes, a 75 cm do tronco, nas camadas de 0–20 e 20–40 cm de profundidade, de parcelas que receberam 0, 3,7 e 7,4 t ha-1 de calcário. O calcário foi aplicado em pré-plantio, incorporado com arado de aivecas e grade aradora, na camada de 0–30 cm de profundidade. Durante o segundo e o terceiro ano de cultivo da goiabeira, avaliaram-se os efeitos da calagem nas propriedades químicas do solo. Aos 42 meses após a incorporação do calcário (terceiro ano de cultivo da goiabeira), realizou-se a amostragem das raízes com trado cilíndrico serrilhado para a avaliação da matéria seca e do teor de cálcio radicular e e também realizou-se a amostragem de folhas. A calagem promoveu a correção da acidez do solo, aumentando a saturação por bases, com conseqüente incremento da disponibilidade e absorção de cálcio pela planta, proporcionando maior desenvolvimento do sistema radicular da goiabeira. Concentrações de cálcio próximas de 30 mmolc dm-3 no solo e teor desse nutriente de 7,5 g kg-1 nas raízes, estiveram associados ao maior crescimento radicular da goiabeira

A CALAGEM NA NUTRIÇÃO E NO DESENVOLVIMENTO DO SISTEMA RADICAL DA CARAMBOLEIRA

The liming can affect the development of the system root of the carambola with implications in the absorption of nutritious. It was aimed at to evaluate the effects of the limestone application in the chemical properties of the soil, in the nutrition of the plant and in the development of the system root of the carambola, cultivated in a Latosol Red acid distrofic. For this, limestone doses were analyzed, zero (control); 3.705 and 7.410 t ha-1, in soil samples collected, in the planting line, to 75 cm of the trunk, in layers of 0-20 and 20-40 cm of depth. The limestone was applied in at planting, incorporate (0-30 cm of depth). During 2o and 3o year of culture of the carambola, the effect of the liming in the soil and the nutrition of the fruit had been accompanied by. In 3o year of culture of the carambola, beyond the chemical analysis of the soil and leves (Ca), it was evaluated dry substance and text of Ca of the root of the fruit. The determination of the concentration of Ca in the soil is an indicative for the diagnosis of the growth potential to radical in carambola in formation phase.A calagem pode afetar o desenvolvimento do sistema radical da caramboleira com implicações na absorção de nutrientes. Objetivou-se avaliar os efeitos da aplicação de calcário nas propriedades químicas do solo, na nutrição da planta e no desenvolvimento do sistema radical da caramboleira, cultivada em um Latossolo Vermelho distrófico ácido. Para isso, testaram-se diferentes doses de calcário, 3,705 e 7,410 t ha-1, em amostras de solo coletadas, na linha de plantio, a 75 cm do tronco, nas camadas de 0-20 e 20-40 cm de profundidade. A testemunha constou de solo sem aplicação de calcário. O calcário foi aplicado em pré-plantio, e incorporado até 30 cm de profundidade. Durante o 2o e 3o ano de cultivo da caramboleira, acompanharam-se os efeitos da calagem no solo e na nutrição da fruteira. No 3o ano de cultivo da caramboleira, além da análise química do solo e das folhas quanto ao nível de cálcio, avaliou-se a matéria seca e teor de Ca das raízes da fruteira. A determinação da concentração de Ca no solo é um indicativo para o diagnóstico do potencial de crescimento radical em caramboleira em fase de formação

Neonatal morbidity associated with late preterm and early term birth: The roles of gestational age and biological determinants of preterm birth

Background: The aim of this study was to elucidate the role of gestational age in determining the risk of neonatal morbidity among infants born late preterm (34-36 weeks) and early term (37-38 weeks) compared with those born full term (39-41 weeks) by examining the contribution of gestational age within the context of biological determinants of preterm birth.Methods: This was a retrospective cohort study. The sample included singleton live births with no major congenital anomalies, delivered at 34-41 weeks of gestation to London-Middlesex (Canada) mothers in 2002-11. Data from a city-wide perinatal database were linked with discharge abstract data. Multivariable models used modified Poisson regression to directly estimate adjusted relative risks (aRRs). The roles of gestational age and biological determinants of preterm birth were further examined using mediation and moderation analyses.Results: Compared with infants born full term, infants born late preterm and early term were at increased risk for neonatal intensive care unit triage/admission [late preterm aRR = 6.14, 95% confidence interval (CI) 5.63, 6.71; early term aRR = 1.54, 95% CI 1.41, 1.68] and neonatal respiratory morbidity (late preterm aRR = 6.16, 95% CI 5.39, 7.03; early term aRR = 1.46, 95% CI 1.29, 1.65). The effect of gestational age was partially explained by biological determinants of preterm birth acting through gestational age. Moreover, placental ischaemia and other hypoxia exacerbated the effect of gestational age on poor outcomes.Conclusions: Poor outcomes among infants born late preterm and early term are not only due to physiological immaturity but also to biological determinants of preterm birth acting through and with gestational age to produce poor outcomes. © The Author 2013; all rights reserved

Experimental investigation on beach morphodynamical process near river mouth

Physical model study on wave influences on river-mouth depositional process is presented. Experiments were performed in a wave basin in order to determine erosion and accretion area due to the combined wave - current flows. An inflow glass channel was designed to reproduce a river mouth model in a 3D wave basin made with a sand bottom. The tests were carried out under three different conditions: River current, waves, wave -current interaction. Measurements of wave heights, beach profiles and bathymetric profiles were made. The results show that in the presence of combined wave-current flows, erosion areas are more evident in vicinity of a mouth with depth and width values greater than depth and width values of inflow channel

Calcário e escória de siderurgia avaliados por análise foliar, acúmulo, e exportação de macronutrientes em cana-de-açúcar

A opção de uso de materiais corretivos alternativos como as escórias de siderurgia, pode influenciar na absorção de nutrientes pela planta e, consequentemente, na diagnose foliar, acúmulo e exportação de nutrientes. Com o objetivo de estudar o efeito da aplicação de doses de escória de siderurgia e de calcário na absorção de macronutrientes pela cana-de-açúcar (variedade SP80-1842), foi instalado em janeiro de 1998, em Ituverava-SP, um experimento de campo. Aplicou-se escória de siderurgia e calcário, em quatro doses equivalentes 0; 1,23; 2,52 e 3,80 t ha-1 de CaCO3, em um Latossolo Vermelho-Amarelo distrófico, em pré-plantio na cana-planta. Determinaram-se, além da produção de colmos, as concentrações de macronutrientes na folha +3 da cana-planta e da cana-soca (aos 120 dias após a emergência dos brotos) e na parte aérea da cana-soca (aos 345 dias após a emergência dos brotos). Os materiais corretivos e as doses não alteraram a absorção de macronutrientes pela cana-de-açúcar. Houve maior acúmulo e exportação de macronutrientes de acordo com as doses de ambos corretivos. A escória de siderurgia comportou-se de modo semelhante ao calcário na nutrição da cana-de-açúcar quanto aos macronutrientes.Slag can be used as an alternative for lime as soil amendment, having influence on nutrient uptake by the plant and, as a result, on leaf analysis and nutrient accumulation. To study the effect of the application of increasing rates of slag and lime stone on the uptake of macronutrients by sugar cane (variety SP 80-1842) an experiment was installed under field conditions, in January 1998, at Ituverava-SP, Brazil. Slag and limestone were applied to the sugarcane crop at planting, in four rates: 0; 1.23; 2.52 and 3.80 t ha-1 of CaCO3, using a Typic Haplorthox. In addition to the cane stalk production a verification was performed for the first and second ratoons (120 days and 345 after the emergence of the shoots, respectively). Macronutrient concentrations on the leaf +3 and in the aerial part of sugar cane for were analysed for the second cutting. Through leaf analysis data it was found that the corrective agents and rates did not modify the degree of absorption of macronutrients by the sugar cane. Slag had some effect on sugarcane evaluation, acting in a similar way in comparison to limestone, in relation to the nutrition of the plant

Anatomical modifications in the cell wall of guava as influenced by calcium

O objetivo deste trabalho foi avaliar modificações na parede celular de goiaba, em frutos de plantas submetidas à aplicação de cálcio (Ca). Frutos de goiabeira cultivar Paluma foram colhidos em área sem aplicação de calcário e com aplicação de corretivo. Os frutos que receberam aplicação de Ca tiveram as paredes celulares e as lamelas médias bem definidas e estruturadas; nos frutos sem aplicação de cálcio, as paredes celulares estavam desestruturadas e com desorganização da lamela média. A aplicação de Ca é efetiva na organização subcelular de frutos de goiabeira e aumenta sua vida de prateleira.The objective of this work was to evaluate modifications in cell walls of guava fruits produced either under liming or not. The study made use of fruits of the Paluma cultivar harvested from nonlimed and limed areas. Fruits harvested from the calcium treated plants had cell walls and the middle lamella well defined and soundly structured. Fruits from the nontreated plants showed poorly structured cell walls and middle lamella. The application of calcium has an important effect on the subcellular structural organization of guava fruit and on the increase of fruits shelf life