Ward Identities and chiral anomalies for coupled fermionic chains

Coupled fermionic chains are usually described by an effective model written in terms of bonding and anti-bonding spinless fields with linear dispersion in the vicinities of the respective Fermi points. We derive for the first time exact Ward Identities (WI) for this model, proving the existence of chiral anomalies which verify the Adler-Bardeen non-renormalization property. Such WI are expected to play a crucial role in the understanding of the thermodynamic properties of the system. Our results are non-perturbative and are obtained analyzing Grassmann functional integrals by means of Constructive Quantum Field Theory methods.Comment: TeX file, 26 pages, 7 figures. Published version, new section added to answer referee remarks and derive the Ward Identites, no modifications in the main resul

Paracamallanus amazonensis sp. n. (Nematoda: Camallanidae) a parasite of the catfish, Hypophthalmus edentatus (Pisces: Hypophthalmidae) of the Brazilian Amazon

Paracamallanus amazonensis sp. n. (Nematoda: Camallanidae) is described from the intestine of a fish called "mapará", Hypophthalmus edentatus (Pisces: Hypophthalmidae) from Marchantaria Island, Solimões River, Amazonas State, Brazil. Of the six species described in the genus, P. amazonensis sp. n. resembles only P. cyathopharynx (BAYUS, 1923) because both have a buccal cavity divided into two parts posterior to the valves. The new species differs from P. cyathopharyrnx in having: 1) a buccal cavity without teeth; 2) 6 pairs of precloacal papillae and a single spicule in the male; 3) a vulva with the posterior lip in the form of a fold which projects anteriorly; 4) a pointed tail in the female. This is the first report of a genus of Paracamallanus YORKE & MAPLESTONE, 1926, in South America

Thermal comfort assessment in a typological non-isolated maternity pig sheds with different types of farrowing systems

Received: February 1st, 2021 ; Accepted: May 8th, 2021 ; Published: May 19th, 2021 ; Correspondence: [email protected] facilities in tropical climates, especially the maternity, have worked with typological systems that have been little studied to determine the influence of the type of farrowing on microenvironmental conditions and its effect on both the sows and the piglets' physiological parameters. Therefore, the aim of the research was evaluate the thermal environment (Temperature Humidity Index - THI and Radiant Thermal Load - RTL) and its influence on some physiological parameters (respiratory frequency - RF and rectal temperature - TRectal) in the sows and piglets in two different types of farrowing systems (Traditional and Slatted), in a typological swine facility located in tropical climates in Colombia. The findings showed that in the two systems, both for sows and piglets, the type of farrowing system did not generate significant differences in the physiological responses RF and TRectal. Also, the RTL did not show significant differences in the two types of farrowing system at the piglets and the sows’ level, without exceeding the maximum allowed levels. Temperature-Humidity Index was above the threshold during all experimental time, being slightly higher at the piglets' level with Slatted systems. These results show that the type of floor has little impact on the conditions of animal thermal comfort at the sows and piglets’ level. However, variables like low-temperature, low radiant energy exchange, and high humidity, which were found mainly at the piglets’ level, could have the highest incidence for not achieving a suitable microenvironment. This means that almost all Colombian pig farming facilities require a redesign of their farrowing system to guarantee better thermal conditions for both piglets and sows

Indicadores para a avaliação da disponibilidade hídrica para o desenvolvimento sustentável da atividade canavieira irrigada.

Para a racionalização do uso dos recursos hídricos e promoção do desenvolvimento sustentável da atividade canavieira na região Centro-Oeste torna-se importante o desenvolvimento de procedimentos metodológicos que possam fornecer subsídios técnicos para o planejamento e gestão setorial - agricultura e recursos hídricos. O presente trabalho apresenta dois indicadores concebidos para a avaliação do potencial da disponibilidade hídrica para atender a demanda projetada de água para o desenvolvimento da atividade canavieira

The role of the observed tropical convection in the generation of frost events in the southern cone of South America

Based on previous results obtained from observations and linear wave theory analysis, the hypothesis that large-scale patterns can generate extreme cold events in southeast South America through the propagation of remotely excited Rossby waves was already suggested. This work will confirm these findings and extend their analysis through a series of numerical experiments using a primitive equation model where waves are excited by a thermal forcing situated in positions chosen according to observed convection anomalies over the equatorial region. The basic state used for these experiments is a composite of austral winters with maximum and minimum frequency of occurrence of generalized frosts that can affect a large area known as the Wet Pampas located in the central and eastern part of Argentina. The results suggest that stationary Rossby waves may be one important mechanism linking anomalous tropical convection with the extreme cold events in the Wet Pampas. The combination of tropical convection and a specific basic state can generate the right environment to guide the Rossby waves trigged by the tropical forcing towards South America. Depending on the phase of the waves entering the South American continent, they can favour the advection of anomalous wind at low levels from the south carrying cold and dry air over the whole southern extreme of the continent, producing a generalized frost in the Wet Pampa region. On the other hand, when a basic state based on the composites of minimum frosts is used, an anomalous anticyclone over the southern part of the continent generates a circulation with a south-southeast wind which brings maritime air and therefore humidity over the Wet Pampas region, creating negative temperature anomalies only over the northeastern part of the region. Under these conditions even if frosts occur they would not be generalized, as observed for the other basic state with maximum frequency of occurrence of generalized frosts

Building performance analysis of a dairy factory in South Iraq: appraisal of a local bio-based envelope

Received: February 4th, 2021 ; Accepted: April 24th, 2021 ; Published: April 29th, 2021 ; Correspondence: [email protected] have a relevant impact on the environment, and building materials cause environmental impacts during all life cycle stages: production, utilization, management and demolition. The global request for more efficient buildings with less environmental impacts has grown during the last years. Among various technologies, thermal insulation has proven to be helpful in reducing emissions by increasing energy conservation. This paper intends to show how the Building Performance Analysis (BPA) supports the decision-making process in many areas where common insulation materials are not available and there is a general reluctance to use local natural materials. A building located in the city of Al Chubaish in Dhi Qar Province in Iraq is examined as a case study. The construction is designed for processing buffalo milk. It was built in the first decade of the century, during the Iraqi conflict, using only the materials available at that time, most of which, concrete bricks, mortar and plaster. Currently, this dairy factory is a very inefficient structure in terms of energy saving. But because its elementary form, it is a perfect example to investigate how a simple exterior wall insulation can improve building performance in extreme environmental conditions. Accordingly, two different models have been created. One is the replica of the real building without any upgrading. The second instead presents a thermal insulation realized with reed bio-based material locally available. Through advanced simulation engines and building performance analysis data integrated into Autodesk Revit, each model has been tested to identify significant improvements in terms of energy savings in this particular stressed background

Sistema de indicadores para a avaliação da sustentabilidade hídrica da atividade canaviera.

O objetivo deste trabalho é apresentar um estudo de caso realizado na Bacia Hidrográfica do Rio Verde (BHRV) para demonstrar a aplicabilidade do Sistema de Indicadores - SISHidro-Cana - para a avaliação da sustentabilidade hídrica da cultura canavieira, proposta por Ferraz (2012), como uma metodologia para avaliar a disponibilidade de água de bacias hidrográficas para subsidiar a proposição de políticas setoriais, ordenação territorial, planejamento agrícola e gestão dos recursos hídricos

Rossby wave propagation during winters of maximum frequency of frost occurrence over the wet pampa

Neste trabalho estudou-se a influência dos padrões de onda extratropicais, que favorecem o desenvolvimento de eventos extremos frios no sudeste Sul-Americano, e em particular na região conhecida como Pampa Úmida. O aquecimento anômalo observado na região do oceano Pacífico tropical ocidental a nordeste da Austrália, durante os invernos de máxima freqüência de ocorrência de Geadas Generalizadas (GG) no centro-leste da Argentina, (região conhecida como Pampa Úmida - PU), atua como disparador de ondas de Rossby, as quais se propagam até o continente, favorecendo assim a ocorrência daqueles eventos. O padrão de propagação obtido nas simulações numéricas com um modelo baroclínico global, mostra o predomínio de um número de onda 3. Adicionalmente, foram analisadas as correlações do vento meridional em altos e baixos níveis observados para os eventos de GG, selecionados dentro dos invernos de máxima freqüência de ocorrência desses eventos. O vento meridional global em 250hPa apresenta regiões com correlação estatisticamente significativa com o vento meridional médio na PU. A configuração obtida no caso do vento meridional global em 250hPa, correlacionado com o vento meridional na PU, pode estar associada ao padrão de propagação das ondas simuladas numericamente a partir da forçante tropical. Igualmente importantes e significativos são os valores de correlação do vento sul nos baixos níveis, em particular para toda região da PU. O padrão de ondas simulado está bem representado pelas significativas correlações entre o vento meridional hemisférico em altos níveis e a temperatura no dia de evento de GG.The influence of extratropical waves on the development of extreme cold events over southeast South America, particularly on the Argentinean Wet Pampa region is studied in this work. An anomalous heating observed over the occidental tropical Pacific Ocean, northeast of Australia, during Austral winters of maximum frequency of Generalized Frost (GF) occurrence over the center-east of Argentina, known as Wet Pampa (WP), acts as a Rossby wave source which generate waves that propagate towards the South American continent favoring the frost events. The wave propagation pattern obtained from simulations using a Global Baroclinic Model shows wavenumber 3 dominance. Additional, upper and lower levels meridional wind correlations during the GF events selected were analyzed. The 250hPa global meridional wind shows a significant correlation (0.9) with the meridional wind at the WP region. The wave propagation pattern observed in this case agrees with that simulated by the model when a heating source is located at the Pacific tropical ocean. Also, significant correlation values were found for the low level southern winds at the WP region. The wave pattern simulated shows a good correlation between the hemispheric meridional wind at higher levels and the air temperature in the day of GF events.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET

Doped carrier formulation of the t-J model: the projection constraint and the effective Kondo-Heisenberg lattice representation

We show that the recently proposed doped carrier Hamiltonian formulation of the t-J model should be complemented with the constraint that projects out the unphysical states. With this new important ingredient, the previously used and seemingly different spin-fermion representations of the t-J model are shown to be gauge related to each other. This new constraint can be treated in a controlled way close to half-filling suggesting that the doped carrier representation provides an appropriate theoretical framework to address the t-J model in this region. This constraint also suggests that the t-J model can be mapped onto a Kondo-Heisenberg lattice model. Such a mapping highlights important physical similarities between the quasi two-dimensional heavy fermions and the high-T$_c$ superconductors. Finally we discuss the physical implications of our model representation relating in particular the small versus large Fermi surface crossover to the closure of the lattice spin gap.Comment: corrected and enlarged versio

Cuidados básicos com fotômetro de chama.

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