Chaotic Planar Piecewise Smooth Vector Fields With Non Trivial Minimal Sets

In this paper some aspects on chaotic behavior and minimality in planar piecewise smooth vector fields theory are treated. The occurrence of non-deterministic chaos is observed and the concept of orientable minimality is introduced. It is also investigated some relations between minimality and orientable minimality and observed the existence of new kinds of non-trivial minimal sets in chaotic systems. The approach is geometrical and involve the ordinary techniques of non-smooth systems.Comment: arXiv admin note: text overlap with arXiv:1307.682

Concentrações e potencial carcinogênico de hidrocarbonetos policíclicos aromáticos derivados de amostradores passivos atmosféricos em uma cidade produtora de óleo/gás (Macaé, Brasil)

Urban centers cause atmospheric pollution and suffer the most from their emissions. Polycyclic aromatic hydrocarbons (PAHs) are persistent toxic substances (PTS) that can be air transported at urban sites and impact human health, causing skin allergies, respiratory diseases, and cancer. Macaé is a southeastern Brazilian coastal city that had an intense process of urbanization and population growth due to the installation of oil companies in the 1970s. The study aimed to evaluate Macaé’s air quality regarding atmospheric PAH occurrence, measured using polyurethane foam passive air samplers (PUF-PAS). PUF disks were deployed along environmental gradients during the 2018–2019 spring/summer in Macaé city and its surroundings. In total, 22 individual PAHs were analyzed by gas chromatography coupled with mass spectrometry. Total PAH air concentrations ranged from 0.3 to 3.3 ng.m-3, pointing out three- to four-membered ring compounds as the most abundant (76%). Among them, phenanthrene, anthracene, and fluoranthene had the highest air concentrations, especially at sampling sites where fossil fuel combustion seemed more prominent. Compared to other cities worldwide, the lower PAH air levels reported in this study may be linked to the influence of marine air masses. As the most carcinogenic PAH compound is benzo[a]pyrene, the results are also given in benzo[a]pyrene-equivalent (BaPeq). BaPeq ranged from 0.02 to 0.10 ng.m-3. This study indicated an environmental trend along urban-industry-background spatial transects. Even though a prominent marine air mass might contribute to efficient air pollution dispersion, in urban/industrial areas, human exposure to carcinogenic chemicals is higher, probably due to local PAH sources inside the urban perimeter of Macaé.Os centros urbanos causam poluição atmosférica e são os que mais sofrem com suas emissões. Os hidrocarbonetos policíclicos aromáticos (HPA) são substâncias tóxicas persistentes que podem ser transportadas por longas distâncias e impactar a saúde humana, causando alergias, doenças respiratórias e câncer. Macaé é uma cidade litorânea do sudeste brasileiro que teve um intenso processo de urbanização e crescimento populacional, associado à instalação de companhias petrolíferas. O estudo teve como objetivo avaliar a qualidade do ar de Macaé quanto à ocorrência de HPA, medidos com amostradores passivos de espumas de poliuretano (EPU). Os discos EPU foram implantados ao longo de gradientes ambientais durante o período primavera/verão 2018–2019 na cidade de Macaé e arredores. Vinte e dois HPA individuais foram analisados por cromatografia gasosa acoplada a espectrômetro de massas. A concentração total de HPA atmosféricos variou de 0,3 a 3,3 ng.m-3, sendo os compostos de três e quatro anéis aromáticos os mais abundantes (76%). Fenantreno, antraceno e fluoranteno apresentaram as maiores concentrações, especialmente em locais onde a queima de combustível fóssil parece ser mais proeminente. Comparando com outros centros urbanos, as baixas concentrações de HPA atmosféricos encontradas no presente estudo podem ser explicadas por retrotrajetórias marinhas de massa de ar. Os resultados também são expressos em benzo[a]pireno-equivalente (B[a]Peq), HPA altamente carcinogênico. O B[a]Peq variou de 0,02 a 0,10 ng.m-3. Este estudo indicou uma tendênciadecrescente no transecto urbano-industrial-controle (ou de fundo). Apesar de uma massa de ar marinha possivelmente contribuir para a eficiente dispersão de poluentes atmosféricos, áreas urbanas/industriais aumentam a exposição humana a compostos carcinogênicos, provavelmente por fontes de HPA, dentro dos perímetros urbanos de Macaé

Periodic solutions of el nino model through the vallis differential system

By rescaling the variables, the parameters and the periodic function of the Vallis differential system we provide sufficient conditions for the existence of periodic solutions and we also characterize their kind of stability. The results are obtained using averaging theory.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Poincare Recurrence Theorem For Non-smooth Vector Fields

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)In this paper, some ergodic aspects of non-smooth vector fields are studied. More specifically, the concepts of recurrence and invariance of a measure by a flow are discussed, and two versions of the classical Poincare Recurrence Theorem are presented. The results allow us to soften the hypothesis of the classical Poincare Recurrence Theorem by admitting non-smooth multivalued flows. The methods used in order to prove the results involve elements from both measure theory and topology.682Sao Paulo Research Foundation (FAPESP) [2013/25828-1, 2013/24541-0]Pronex/FAPEG/CNPq [2012 10 26 7000 803]PROCAD-CAPES [88881.068462/2014-01]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Detecting periodic orbits in some 3D chaotic quadratic polynomial differential systems

Using the averaging theory we study the periodic solutions and their linear stability of the 3–dimensional chaotic quadratic polynomial differential systems without equilibria studied in [3]. All these differential systems depend only on one–parameter201141150CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE GOIÁS - FAPEGFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP478230/2013-3; 443302/2014-688881.030454/ 2013-012012/10 26 7000 8032014/02134-7; 2013/25828-1; 2014/18508

Morphological analysis of testes from post-hatch chicks submitted to temperature variation during incubation - doi: 10.4025/actascibiolsci.v33i2.8187

This study aimed to evaluate the effects of temperature variation during incubation on testicular morphology of post-hatch chicks. We utilized 60 eggs incubated under different temperatures: Group 1 – 37.5°C; Group 2 – 39.5°C; and Group 3 – 34°C. Chicks were weighted and the testes were histologically analyzed. All eggs from Group 3 showed embryonic death. There were no significant differences in body weight and testicular morphology between Groups 1 and 2; however, there was a difference in the diameter of the seminiferous tubules (p < 0.001). The increase in temperature to 39.5°C during incubation causes a decrease in diameter of the seminiferous tubules.This study aimed to evaluate the effects of temperature variation during incubation on testicular morphology of post-hatch chicks. We utilized 60 eggs incubated under different temperatures: Group 1 – 37.5°C; Group 2 – 39.5°C; and Group 3 – 34°C. Chicks were weighted and the testes were histologically analyzed. All eggs from Group 3 showed embryonic death. There were no significant differences in body weight and testicular morphology between Groups 1 and 2; however, there was a difference in the diameter of the seminiferous tubules (p < 0.001). The increase in temperature to 39.5°C during incubation causes a decrease in diameter of the seminiferous tubules