Plastic Deformation of 2D Crumpled Wires

When a single long piece of elastic wire is injected trough channels into a confining two-dimensional cavity, a complex structure of hierarchical loops is formed. In the limit of maximum packing density, these structures are described by several scaling laws. In this paper it is investigated this packing process but using plastic wires which give origin to completely irreversible structures of different morphology. In particular, it is studied experimentally the plastic deformation from circular to oblate configurations of crumpled wires, obtained by the application of an axial strain. Among other things, it is shown that in spite of plasticity, irreversibility, and very large deformations, scaling is still observed.Comment: 5 pages, 6 figure

A theoretical approach of adaptation to stress and implications for evaluation and research

[Excerpt] The study of adaptation to occupational stress is a major topic of research on psychology, and other social sciences. In fact, data suggests that employees face significant levels of tension at work, and that there is an increasing of sources of stress, both in terms of intensity and diversity [1]. In this chapter, we analyze adaptation to stress by focusing at the individual level, discussing how professionals evaluate and cope with stressors that impose significant efforts of adjusting. However, this does not mean that occupational stress is strictly an individual phenomenon; by the contrary, a better understanding of stress at work should assume a multifactor perspective, where the employee, the employer, the work organization, the public policies and laws of work, and the cultural values and norms that influence professional relations between all these agents, play together and determine if the working activity will be a pleasant or dysfunctional experience for professionals. Despite the importance of considering all these factors when studying the working activity, it is also obvious that the way each worker adapt to their working conditions is a pivotal factor to understand how this activity can represent a source of personal gratification or, by the contrary, can ended represent a negative, or even indifferent, experience. [...]info:eu-repo/semantics/publishedVersio

Fungos associados ao híbrido interespecíico da palma de óleo no Estado do Pará.

Edição dos resumos do 44º Congresso Brasileiro de Fitopatologia, 2011, Bento Gonçalves. Resumo 1174

Angiogenesis in NSCLC: is vessel co-option the trunk that sustains the branches?

The critical role of angiogenesis in tumor development makes its inhibition a valuable new approach in therapy, rapidly making anti-angiogenesis a major focus in research. While the VEGF/VEGFR pathway is the main target of the approved anti-angiogenic molecules in NSCLC treatment, the results obtained are still modest, especially due to resistance mechanisms. Accumulating scientific data show that vessel co-option is an alternative mechanism to angiogenesis during tumor development in well-vascularized organs such as the lungs, where tumor cells highjack the existing vasculature to obtain its blood supply in a non-angiogenic fashion. This can explain the low/lack of response to current anti-angiogenic strategies. The same principle applies to lung metastases of other primary tumors. The exact mechanisms of vessel co-option need to be further elucidated, but it is known that the co-opted vessels regress by the action of Angiopoietin-2 (Ang-2), a vessel destabilizing cytokine expressed by the endothelial cells of the pre-existing mature vessels. In the absence of VEGF, vessel regression leads to tumor cell loss and hypoxia, with a subsequent switch to a neoangiogenic phenotype by the remaining tumor cells. Unravelling the vessel co-option mechanisms and involved players may be fruitful for numerous reasons, and the particularities of this form of vascularization should be carefully considered when planning anti-angiogenic interventions or designing clinical trials for this purpose. In view of the current knowledge, rationale for therapeutic approaches of dual inhibition of Ang-2 and VEGF are swiftly gaining strength and may serve as a launchpad to more successful NSCLC anti-vascular treatments.info:eu-repo/semantics/publishedVersio

Isolation of Surfactant-Resistant Pseudomonads from the Estuarine Surface Microlayer

Bioremediation efforts often rely on the application of surfactants to enhance hydrocarbon bioavailability. However, synthetic surfactants can sometimes be toxic to degrading microorganisms, thus reducing the clearance rate of the pollutant. Therefore, surfactant-resistant bacteria can be an important tool for bioremediation efforts of hydrophobic pollutants, circumventing the toxicity of synthetic surfactants that often delay microbial bioremediation of these contaminants. In this study, we screened a natural surfactant-rich compartment, the estuarine surface microlayer (SML), for cultivable surfactant-resistant bacteria using selective cultures of sodium dodecyl sulfate (SDS) and cetyl trimethylammonium bromide (CTAB). Resistance to surfactants was evaluated by colony counts in solid media amended with critical micelle concentrations (CMC) of either surfactants, in comparison with non-amended controls. Selective cultures for surfactant-resistant bacteria were prepared in mineral medium also containing CMC concentrations of either CTAB or SDS. The surfactantresistant isolates obtained were tested by PCR for the Pseudomonas genus marker gacA gene and for the naphthalene-dioxygenase-encoding gene ndo. Isolates were also screened for biosurfactant production by the atomized oil assay. A high proportion of culturable bacterioneuston was tolerant to CMC concentrations of SDS or CTAB. The gacA-targeted PCR revealed that 64% of the isolates were Pseudomonads. Biosurfactant production in solid medium was detected in 9.4% of tested isolates, all affiliated with genus Pseudomonas. This study shows that the SML is a potential source of surfactant-resistant and biosurfactant-producing bacteria in which Pseudomonads emerge as a relevant group

Efficiency of different techniques in seismic strengthening of RC beam-column joints

In the last years several techniques have been proposed and used for the seismic strengthening of reinforced concrete (RC) beam-column joints using fiber reinforced polymers (FRP). The Near Surface Mounted (NSM) technique uses FRP bars or laminates inserted into grooves opened on the concrete cover and filled with epoxy adhesive. In the Mechanically Fastened and Externally Bonded Reinforcement (MF-EBR) technique, multidirectional laminates of carbon fiber reinforced polymers (MDL-CFRP) are simultaneously bonded with epoxy adhesive and mechanically fixed with anchors to the faces of the elements to be strengthened. With the aim of comparing the seismic efficiency of NSM and MF-EBR techniques, tests with RC joints, representative of the buildings construction practice in Southern European countries until the early 1970s were carried. The experimental campaign comprises cyclic tests on seven full-scale RC joints with distinct configurations when both, NSM and MF-EBR techniques, are used. The tests are described and the main results are presented and analyzed

Estimativa de área foliar e de modelos de crescimento em plantas de lima ácida ?Tahiti? por métodos diretos e indiretos.

O trabalho visou estimar a área foliar total (AFT em m 2) de plantas de lima ácida ?Tahiti? (Centros latifólia Tan) no tempo, desenvolver modelos de estimativa de AFT com base em variáveis biométricas das plantas e avaliar o desempenho do método IAF-LUX nas estimativas de AFT. O estudo foi conduzido na Fazenda Boa Vista, pertencente à Iaçu Agropastoril Ltda., localizada no município de Iaçu, semiárido baiano, sob as coordenadas geográficas 12°46?00? de latitude sul e 40°13?00? de longitude oeste, e altitude de 280 m.PDF. 101_11

Laminados multi-direccionais de CFRP para aplicações em engenharia civil

Recentemente tem vindo a ser proposta uma nova técnica de reforço utilizando polímeros reforçados com fibras de carbono (CFRP) na reabilitação estrutural de estruturas de betão, que consiste na aplicação de laminados multi-direccionais de CFRP (MDL-CFRP). Estes laminados são simultaneamente colados e fixados mecanicamente através de ancoragens. Neste contexto, foi desenvolvido um MDL-CFRP e, para avaliar as suas potencialidades no reforço de estruturas de betão foram realizados ensaios de arranque directo. O presente trabalho descreve os ensaios realizados e analisa os principais resultados obtidos

Bond behavior between concrete and multi-directional CFRP laminates using the MF-EBR strengthening technique

The strengthening technique based on the application of multi-directional laminates of CFRP (MDL-CFRP) simultaneously glued and anchored to the surface of the elements to be strengthened has been recently proposed. This technique was designated Mechanically Fastened and Externally Bonded Reinforcement (MF-EBR) and combines the fasteners from the MF-FRP technique with the externally glued properties from the EBR. With the aim of assessing the potentialities of this technique for seismic retrofitting, three interior RC beam-column joints were strengthened according to the MF-EBR technique and tested. This work presents the entire test program executed, including test configuration, results and corresponding analysis.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/ECM/74337/2006.FEDER- Operational Program for Competitiveness Factors – COMPET

Seismic strengthening of beam-column joints with multi-directional CFRP laminates

Technical Report 11-DEC/E-13This work is supported by FEDER funds through the Operational Programme for Competitiveness Factors – COMPETE and National Funds through FCT – Portuguese Foundation for Science and Technology under the project PTDC/ECM/74337/2006. The authors acknowledge the materials generously supplied by Hilti Portugal - Produtos e Serviços Lda., S&P Clever Reinforcement Ibérica Lda. and SECIL