An adaptive load stepping algorithm for path-dependent problems based on estimated convergence rates

A new adaptive (automatic) time stepping algorithm, called RCA (Rate of Convergence Algorithm) is presented. The new algorithm was applied in nonlinear finite element analysis of path-dependent problems. The step size is adjusted by monitoring the estimated convergence rate of the nonlinear iterative process. The RCA algorithm is relatively simple to implement, robust and its performance is comparable to, and in some cases better than, the automatic load incrementaion algorithm existent in commercial codes. Discussions about the convergence rate of nonlinear iterative processes, an estimation of the rate and a study of the parameters of the RCA algorithm are presented. To show the capacity of the algorithm to adjust the increment size, detailed discussions based on results for different limit load analyses are presented. The results obtained by RCA algorithm are compared with those by ABAQUS®, one of the most powerful nonlinear FEA (Finite Element Analysis) commercial software, in order to verify the capability of RCA algorithm to adjust the increment size along nonlinear analyses

Morphology of the Female Receptaculum Seminis of Euschistus heros (FABRICIUS, 1798) (INSECTA: HEMIPTERA: PENTATOMIDAE)

Abstract Euschistus heros (Fabricius, 1798) (Heteroptera: Pentatomidae) is a soybean pest in Brazil. It has a reproductive success that may be associated with the female receptaculum seminis or spermatheca, a reproductive organ for spermatozoa storage until the oocyte fertilization. This study describes the anatomy and histology of the female receptaculum seminis in E. heros. The female receptaculum seminis was dissected and analyzed with a stereomicroscope, following standard procedures for histological and histochemical analyses. The female receptaculum seminis of E. heros has a spherical caspula seminalis and a duct. The epithelial cells of the capsula seminalis have two cell layers with basal one presenting columnar cells with a collecting canaliculus opening in the lumen. The apical layer has cuboidal cells. The cytoplasm in both cell layers was rich in protein. These features suggest a secretory function of these cells. The duct has four regions characterized by muscular pars intermedialis with anterior and posterior cuticular flanges, an elongated and narrow distal ductus receptaculi, a well-developed enlarged vesicular area, and a proximal ductus receptaculi, which indicate several functions, such as control the release and transport of spermatozoa and secretory. These results contribute to the comprehension of the reproductive biology of this agricultural pest

On two species of Ichthyouris (Nematoda: Pharyngodonidae) parasites of Mesonauta festivus (Pisces: Cichlidae) in the Brazilian Amazon region

Two species of nematodes belonging to the genus Ichthyouris Inglis, 1962 (I. ro and I. bursata), were collected from the cichlid fish Mesonauta festivus in the central Brazilian Amazon region. Both species are reported in this locality for the first time. I. bursata is reported in a new host, M. festivus, and this is the first report of I. ro parasitizing its type host in Brazil. We provide a more detailed description for I. ro, including morphological aspects that were not mentioned in the original description. © 2018 Universidad Nacional Autonoma de Mexico. All rights reserved

Behaviour of diferent types of chitosan membranes implanted in horses

ABSTRACT Chitosan has been successfully used as a biomaterial with several purposes in many species. In this study, chitosan membranes were produced with six different types of materials, and their behavior were evaluated upon implantation in the subcutaneous tissue of the flank of twelve healthy horses. We assessed chitosan membranes obtained from commercial chitosan, impregnated or not with silver nanoparticles, sterilized with ethylene oxide (CCEO, n=3; CCSNEO, n=3) or by ultraviolet radiation (CCUR, n=3; CCSNUR, n=3), and chitosan membranes obtained from squid gladius, sterilized with ethylene oxide (SCEO, n=6) or by ultraviolet radiation (SCUR, n=6). The same animals were randomly used in two experimental groups, with a minimum interval of 60 days between procedures, respecting the fact of only one flank side, left or right, be under evaluation by experimental period. After preparation of the membranes and implantation in the flank subcutaneous tissue of the horses, macroscopic and ultrasonographic evaluations of the implant regions were performed, as well as physical examination, blood count and fibrinogen measurement. No clinical or laboratory abnormalities were observed. All animals that received commercial chitosan membranes, regardless of the preparation technique, showed rejection to the biomaterials, considering that 100% of the surgical wounds presented dehiscence of suture and expulsion of the implants. The animals that received squid gladius chitosan membranes showed success in the treatment, with healing by primary intention of the surgical wound. We conclude that squid gladius chitosan membranes are biocompatible and biodegradable when implanted in the subcutaneous tissue of the flank of healthy horses

Qualidade tecnológica em diferentes porções do colmo e produtividade da cana-de-açúcar sob efeito de maturadores

O objetivo deste trabalho foi avaliar a qualidade tecnológica da cana-de-açúcar, variedade RB855453, nas diversas porções do colmo, decorrente da aplicação de maturadores com diferentes mecanismos de ação e a influência na produtividade e na margem de contribuição agrícola. O delineamento experimental foi em blocos casualizados, com seis repetições. Os tratamentos constituíram-se da aplicação de três maturadores, sendo dois da classe dos inibidores do crescimento - glifosato, sulfometuron metil, e um da classe dos retardantes do crescimento - KNO3, com a adição de 1% de óleo vegetal, e a maturação natural como testemunha. Os tratamentos com KNO3 e sulfometuron metil, assim como a testemunha, não promoveram prejuízos ao desenvolvimento dos colmos. Os tratamentos com glifosato e sulfometuron metil propiciaram melhoria na qualidade tecnológica da matéria-prima, determinada até os 35 dias após aplicação, contribuindo para o processo de maturação e possibilitando antecipar o corte em relação à maturação natural (testemunha) e ao tratamento com KNO3, propiciando maior retorno econômico. O tratamento com glifosato reduziu a produtividade de colmos, mas elevou a pol da cana na porção superior dos colmos, possibilitando maior altura de desponte

SECAS E OS IMPACTOS NA REGIÃO SUL DO BRASIL

Embora eventos de secas sejam menos frequentes na Região Sul, se comparado com outras regiões do Brasil, quando ocorrem impactam o abastecimento de água, produção agrícola e a geração de energia elétrica. Portanto, a avaliação dos impactos da seca no setor agrícola e nos recursos hídricos, são de extrema importância para a gestão de riscos nesta região. Neste estudo avaliou-se os principais eventos de secas e seus impactos entre 1998 a 2020 (maio) na Região Sul do Brasil. Para isto, foram utilizados índices de secas calculados a partir de dados de precipitação, vazão e dados derivados de satélite. De acordo com o Índice de Precipitação Padronizada (SPI), o evento mais severo de seca ocorreu no estado do Paraná em 2006. Como consequência, registrou-se valores de área agro-produtivas afetada acima de 80% e seca hidrológica excepcional na bacia hidrográfica afluente (BHA) à usina hidrelétrica (UHE) Segredo, segundo o Índice de Vazão Padronizada (SSFI), além de vazões afluentes abaixo do percentil 90 durante 50% do ano. Em Santa Catarina e no Rio Grande do Sul, os eventos de secas de maior severidade ocorreram em 2012/2013. Apesar disso, os percentuais de áreas agro-produtivas afetadas foram inferiores aos verificados para 2019/2020. Com relação aos recursos hídricos, o SSFI indicou seca excepcional na BHA ao reservatório da UHE Passo Real, e foi observada vazão abaixo do percentil 90 no primeiro semestre de 2012. No evento de seca 2019/2020, o primeiro trimestre de 2020 foi o mais crítico em termos de intensidade e expansão, como mostrado pelo Índice Integrado de Seca, em que 100% dos municípios de toda a região foram classificados em condição de seca. O impacto deste evento pode ser observado pelo SSFI da BHA ao reservatório da UHE Itaipu, com menores valores registrados a partir de janeiro de 2020. Este evento pode estar associado à influência da fase negativa da Oscilação Decadal do Pacífico e condições de neutralidade no Pacífico Equatorial

Review of Solar Energetic Particle Prediction Models

Solar Energetic Particle (SEP) events are interesting from a scientific perspective as they are the product of a broad set of physical processes from the corona out through the extent of the heliosphere, and provide insight into processes of particle acceleration and transport that are widely applicable in astrophysics. From the operations perspective, SEP events pose a radiation hazard for aviation, electronics in space, and human space exploration, in particular for missions outside of the Earth’s protective magnetosphere including to the Moon and Mars. Thus, it is critical to improve the scientific understanding of SEP events and use this understanding to develop and improve SEP forecasting capabilities to support operations. Many SEP models exist or are in development using a wide variety of approaches and with differing goals. These include computationally intensive physics-based models, fast and light empirical models, machine learning-based models, and mixed-model approaches. The aim of this paper is to summarize all of the SEP models currently developed in the scientific community, including a description of model approach, inputs and outputs, free parameters, and any published validations or comparisons with data