Heavy Load Rollers in Logistic Systems

Wheels with polyurethane bandages are in common use in logistic systems with friction gear actuation. Many research projects have studied the mechanical construction of these heavy load wheels. The studies have been theoretical as well as experimental. Research interests at the department of machine elements include the wear in the presence of intermediate material on the contact area between the bandage surface and the contact surface on which the wheel rolls off. This problem, which is observed when examining this tribochemical system, has not been studied before. Within this project both one-phase intermediate materials such as sand, water, cutting-cooling-emulsion, metal splinters and two-phase intermediate materials such as sand/water and combinations of the latter were taken into consideration. In addition, the exposure of the bandage hardness, the cross linking agent of the polyurethane, the mechanical stress, and the slip are observed. The analysis of the experimental results indicates that friction gear actuators can be constructed abrasion-optimised, taking into account special interfering effects in the form of intermediate materials in the contact area

Invasive earthworms reduce chemical defense and increase herbivory and pathogen infection in native trees

Recent research shows that earthworms can alter defense traits of plants against herbivores and pathogens by affecting soil biochemistry. Yet, the effects of invasive earthworms on defense traits of native plants from previously earthworm-free ecosystems as well as the consequences for multitrophic interactions are virtually unknown. Here we use a combination of an observational study and a complementary experimental study to investigate the effects of invasive earthworms on leaf defense traits, herbivore damage and pathogen infection in two poplar tree species (Populus balsamifera and Populus tremuloides) native to North American boreal forests. Our observational study showed that earthworm invasion was associated with enhanced leaf herbivory (by leaf-chewing insects) in saplings of both tree species. However, we only detected significant shifts in the concentration of chemical defense compounds in response to earthworm invasion for P. balsamifera. Specifically, leaf phenolic concentrations, including salicinoids and catechin, were lower in P. balsamifera from earthworm-invaded sites. Our experimental study confirmed an earthworm-induced reduction in leaf defense levels in P. balsamifera for one of the defense compounds, tremulacin. The experimental study additionally showed that invasive earthworms reduced leaf dry matter content, potentially increasing leaf palatability, and enhanced susceptibility of trees to infection by a fungal pathogen, but not to aphid infestation, in the same tree species. Synthesis. Our results show that invasive earthworms can decrease the concentrations of some chemical defense compounds in P. balsamifera, which could make them susceptible to leaf-chewing insects. Such potential impacts of invasive earthworms are likely to have implications for tree survival and competition, native tree biodiversity and ecosystem functioning

Monitoramento hidrometeorológico em bacias rurais do Bioma Mata Atlântica.

Visando estabelecer estudos sobre a hidrologia de bacias com uso agrícola nas regiões tropicais, foram instaladas redes de instrumentação hidrometeorológica em duas bacias rurais. Caracterizadas por um mosaico de classes de cobertura e uso da terra, na Mata Atlântica Fluminense, as bacias são: a do córrego Pito Aceso, no Município de Bom Jardim, região Serrana Fluminense, e a bacia dos Rios Guapiaçu-Macacu, cuja drenagem tem sua foz na Baía de Guanabara. Os resultados obtidos no monitoramento provêm informações essenciais para parametrizar modelos simuladores de processos de fluxo de água e transporte de nutrientes e sedimentos. No projeto AgroHidro, a associação do monitoramento ao uso de modelos visa prover maior conhecimento dos processos de hidrologia em bacias, bem como de suas interações com os sistemas agrícolas

From ecosystems to socio-economic benefits: A systematic review of coastal ecosystem services in the Baltic Sea

Highlights: • We summarized 20 ecosystem services provided by coastal Baltic ecosystems. • Information on how services translate into socio-economic benefits is lacking. • The deep knowledge gap impairs the sustainable management of the benefits. • We propose a framework with four key measures to close this knowledge gap. • Toxins and Nutrients are the most well-document pressures to these services. Abstract: Seagrass meadows, algal forests and mussel beds are widely regarded as foundation species that support communities providing valuable ecosystem services in many coastal regions; however, quantitative evidence of the relationship is scarce. Using the Baltic Sea as a case study, a region of significant socio-economic importance in the northern hemisphere, we systematically synthesized the primary literature and summarized the current knowledge on ecosystem services derived from seagrass, macroalgae, and mussels (see animated video summary of the manuscript: Video abstract). We found 1740 individual ecosystem service records (ESR), 61% of which were related to macroalgae, 26% to mussel beds and 13% to seagrass meadows. The most frequently reported ecosystem services were raw material (533 ESR), habitat provision (262 ESR) and regulation of pollutants (215 ESR). Toxins (356 ESR) and nutrients (302 ESR) were the most well-documented pressures to services provided by coastal ecosystems. Next, we assessed the current state of knowledge as well as knowledge transfer of ecosystem services to policies through natural, social, human and economic dimensions, using a systematic scoring tool, the Eco-GAME matrix. We found good quantitative information about how ecosystems generated the service but almost no knowledge of how they translate into socio-economic benefits (8 out of 657 papers, 1.2%). While we are aware that research on Baltic Sea socio-economic benefits does exist, the link with ecosystems providing the service is mostly missing. To close this knowledge gap, we need a better analytical framework that is capable of directly linking existing quantitative information about ecosystem service generation with human benefit

Etapas metodológicas para a modelagem do nitrogênio na água na bacia Guapi-Macacu, Rio de Janeiro, RJ.

A qualidade da água depende de muitos fatores naturais e antrópicos. Estes impactos precisam ser caracterizados e quantificados para subsidiar cenários futuros e a gestão de recursos hídricos no âmbito das bacias hidrográficas. A Bacia Guapi-Macacu, pertencente ao Bioma Mata Atlântica, é a terceira no ranking de abastecimento de água no Estado do Rio de Janeiro. O propósito deste trabalho foi apresentar as etapas metodológicas para a modelagem hidrológica das formas de nitrogênio nesta bacia. Nesse caso, o modelo hidroquímico J2000-S foi aplicado. A fim de calibrar e validar o modelo, foi instalada uma rede de monitoramento hidrometeorológica e de qualidade da água. Dados secundários também foram organizados e utilizados. Etapas do trabalho: coleta e análise de dados, delimitação das unidades de resposta hidrológica; calibração e validação temporal do modelo hidroquímico; validação espacial e análise de incertezas. A principal fonte de nitrogênio é o esgoto doméstico, seguida das fontes difusas relacionadas à agricultura. Concluiu-se que a disponibilidade de dados é um grande desafio, mas a implantação de redes de monitoramento sólidas pode fornecer os dados necessários para a modelagem

Modelagem de processos hidrológicos em bacias de mesoescala escassamente monitoradas na Mata Atlântica, RJ, Brasil.

A Bacia Hidrográfica do Guapi-Macacu (BHGM), situada na região metropolitana do Rio de Janeiro, é responsável pelo abastecimento de mais de dois milhões de pessoas. A região é sujeita a inundações e deslizamentos no período chuvoso, e escassez hídrica na estação seca, com riscos para o abastecimento doméstico e agrícola nos anos de menor precipitação. Ferramentas de modelagem podem colaborar para a gestão integrado de recursos hídricos e apoiar a tomada de decisão. Este estudo utilizou o modelo hidrológico J2K, desenvolvido na plataforma Jena Adaptable Modeling System (JAMS), para representar o comportamento hidrológico da BHGM. Os procedimentos de parametrização e calibração do modelo foram baseados em dados de campo e de séries temporais meteorológicas e de vazão. O modelo parametrizado para a BHGM foi aplicado numa bacia adjacente, a Bacia Dois Rios (BHDR). Os indicadores de desempenho do modelo foram satisfatórios a bons para ambas as bacias e mostraram a viabilidade de aplicar conjuntos de parâmetros obtidos a partir de bacias instrumentadas em âmbito regional, i.e., em bacias semelhantes quanto às características geomorfológicas e climatológicas

The Prenective View of Propositional Content

Beliefs have what I will call ‘propositional content’. A belief is always a belief that so-and-so: a belief that grass is green, or a belief that snow is white, or whatever. Other things have propositional content too, such as sentences, judgments and assertions. The Standard View amongst philosophers is that what it is to have a propositional content is to stand in an appropriate relation to a proposition. Moreover, on this view, propositions are objects, i.e. the kind of thing you can refer to with singular terms. For example, on the Standard View, we should parse the sentence ‘Simon believes that Sharon is funny’ as: [Simon] believes [that Sharon is funny]; ‘Simon’ is a term referring to a thinking subject, ‘that Sharon is funny’ is a term referring to a proposition, and ‘x believes y’ is a dyadic predicate expressing the believing relation. In this paper, I argue against the Standard View. This is how I think we should parse ‘Simon believes that Sharon is funny’: [Simon] believes that [Sharon is funny]; here we have a singular term, ‘Simon’, a sentence ‘Sharon is funny’, and a ‘prenective’ joining them together, ‘x believes that p’. On this Prenective View, we do not get at the propositional content of someone’s belief by referring to a reified proposition with a singular term; we simply use the sentence ‘Sharon is funny’ to express that content for ourselves. I argue for the Prenective View in large part by showing that an initially attractive version of the Standard View is actually vulnerable to the same objection that Wittgenstein used against Russell’s multiple-relation theory of judgment

Priority monism and part/whole dependence

Priority monism is the view that the cosmos is the only independent concrete object. The paper argues that, pace its proponents, Priority monism is in conflict with the dependence of any whole on any of its parts: if the cosmos does not depend on its parts, neither does any smaller composit