A Roadmap for developing an Industrial Continuous Ultrasonic Welding Process for Thermoplastic Composites

The increasing use of fibre-reinforced plastics in the aerospace industry leads to challenges in joining these materials. The traditionally used mechanical fasteners introduce damage when used in composites by disrupting the fibres. However, thermoplastic composites allow for fusion bonding processes to join parts. Ultrasonic welding has shown to be a very promising high-speed fusion-bonding technique for thermoplastic composites. At the moment, a thorough understanding of the process is required to upscale the process for industrial usage. This study focuses on defining a roadmap to develop continuous ultrasonic welding to an industrially applicable level by presenting the current state of the art, ongoing developments, requirements, and challenges

A Roadmap for developing an Industrial Continuous Ultrasonic Welding Process for Thermoplastic Composites

The increasing use of fibre-reinforced plastics in the aerospace industry leads to challenges in joining these materials. The traditionally used mechanical fasteners introduce damage when used in composites by disrupting the fibres. However, thermoplastic composites allow for fusion bonding processes to join parts. Ultrasonic welding has shown to be a very promising high-speed fusion-bonding technique for thermoplastic composites. At the moment, a thorough understanding of the process is required to upscale the process for industrial usage. This study focuses on defining a roadmap to develop continuous ultrasonic welding to an industrially applicable level by presenting the current state of the art, ongoing developments, requirements, and challenges.Aerospace Manufacturing TechnologiesAerospace Structures & Computational MechanicsStructural Integrity & Composite

Efeito de sistemas de produção e doses de adubo de liberação lenta no estado nutricional de porta-enxerto cítrico The effect of production systems and doses of controlled-release fertilizer on the nutritional status of citrus rootstock

O sistema de produção do porta-enxerto, antes da repicagem, pode modificar o sistema radicular das plântulas e a resposta destas à adubação. Assim, o objetivo desse trabalho foi avaliar os efeitos de três sistemas de produção do limoeiro 'Cravo' e de cinco doses de um adubo de liberação lenta, aplicados após a repicagem, sobre o estado nutricional do limoeiro 'Cravo' no ponto de enxertia. O experimento foi conduzido, sob viveiro telado, em esquema fatorial 3 x 5, com sete repetições e uma planta por parcela. Os sistemas de produção do porta-enxerto foram: 1- produção em tubetes e citrovasos preenchidos com substrato comercial composto por casca de pínus; 2- produção em tubetes e citrovasos preenchidos com substrato composto por bagaço de cana-de-açúcar + torta de filtro (3:2; v:v), e 3- produção em blocos prensados e citrovasos constituídos pela prensagem do substrato utilizado no sistema 2. As doses de adubo de liberação lenta, fórmula NPK 14-14-14, foram: 5; 10; 15; 20 e 25 g/planta. O sistema de produção do porta-enxerto, antes da repicagem, influenciou na resposta do limoeiro 'Cravo' à adubação após a repicagem. No ponto de enxertia, as plantas cultivadas no sistema de blocos prensados apresentaram menores teores foliares de P, K e Fe em relação às plantas provenientes de tubetes, mas apresentaram maiores médias de crescimento (peso seco do sistema radicular, peso seco de folhas, peso seco de caules e diâmetro do caule). Plantas cultivadas no sistema 1 apresentaram sintomas foliares de deficiência de Fe, enquanto as plantas dos outros dois sistemas apresentaram sintomas foliares de deficiência de Mg.<br>The production system of citrus rootstock before the transplanting can modify the seedlings root system and the response of these to fertilization. The objective of this experiment was to evaluate the effects of three production systems of 'Rangpur' lime tree and five doses of a controlled-release fertilizer, applied after transplanting, on the nutritional status of rootstock in the grafting point. The experiment was carried out, under a screen-protected nursery, in a factorial scheme 3 x 5, with seven replicates and one plant per experimental plot. The production systems of citrus rootstock were: 1 - production in stiff plastic tubes filled up with commercial substrate constituted of pinus bark; 2 - production in stiff plastic tubes filled up with substrate constituted of industrial residues of the region, that is, sugarcane bagasse + industrial sugarcane plant residues, (3:2; v:v); and 3 - production in pressed blocks constituted of the pressed substrate used in system 2. The five doses of controlled-release fertilizer formula NPK 14-14-14 were 5, 10, 15, 20 and 25 g/plant. The production system of citrus rootstock before transplanting, influenced the plant response to the fertilization after transplanting. In the grafting point, the plants grown under the pressed block system presented smaller contents of P, K, and Fe in comparison to plants under grown in stiff plastic tubes system, but presented larger growth (root system dry matter, leaf dry matter, stem dry matter and stem diameter). Plants grown in system 1 presented iron deficiency symptoms in leaves, while plants from the other two systems presented magnesium deficiency symptoms in leaves

Desempenho radicular de mudas de eucalipto produzidas em diferentes recipientes e substratos Root performace of eucalyptus stecklings, produced in different containers and substrates

O trabalho teve como objetivo verificar o desempenho, em sacolas, de clones de eucalipto, produzidos em diferentes recipientes e substratos, com ênfase na persistência das deformações radiculares originadas no viveiro e na produção de raízes. As mudas foram produzidas em tubetes (50 cm³) e em blocos prensados (40 x 60 x 7 cm - 16.800 cm³), sendo utilizados como substratos: casca de arroz carbonizada com casca de eucalipto, bagaço de cana com torta de filtro; e turfa. As mudas, com 90 dias, foram transplantadas para sacos plásticos (20 L), com solo da área de plantio. O experimento foi conduzido em delineamento inteiramente casualizado, em esquema fatorial 2 x 7, constituído por dois clones (híbridos naturais de Eucalyptus grandis Hill ex Maiden e E. saligna Smith) e sete tratamentos, com variação de recipientes e substrato, com quatro repetições, constituídas por quatro plantas. Dois meses após o transplantio, as plantas foram avaliadas quanto ao crescimento em diâmetro ao nível do solo, altura da parte aérea, número de raízes emitidas, comprimento, área superficial e deformação do sistema radicular. As plantas originadas de mudas produzidas em blocos prensados apresentaram melhor desempenho nas avaliações realizadas em relação às dos tubetes. As deformações radiculares causadas por recipientes de paredes rígidas tendem a persistir após a fase de viveiro.<br>The objective of this work was to evaluate the performance after the planting of eucalyptus stecklings, produced in different containers and substrates, with emphasis in root production and deformations. The stecklings were produced in tubes (50 cm³) and in pressed blocks (40 x 60 x 7cm -16800 cm³), and used as substrates: carbonized rice husk and eucalyptus husk; sugarcane bagasse and sugarcane filter cake; and peat. At ninety days the stecklings were transplanted to plastic bags (20 L), with soil from the planting area. This experiment was set in a completely randomized design, arranged in a 2 x 7factorial, constituted by two clones (natural hybrid of Eucalyptus grandis Hill ex Maiden and E. saligna Smith) and seven treatments, with variation of containers and substrates, with four replicates, constituted by four plants. At two months, the cuttings were evaluated considering their root collar diameter, height, number, length and superficial area of emitted roots, and system root deformations. The plants originated of stecklings produced in pressed blocks presented better performance than the tubes ones. The root deformations caused by containers persist after the nursery stage

Transient gain of function of cannabinoid CB1 receptors in the control of frontocortical glucose consumption in a rat model of Type-1 diabetes

Here we aimed to unify some previous controversial reports on changes in both cannabinoid CB1 receptor (CB1R) expression and glucose metabolism in the forebrain of rodent models of diabetes. We determined how glucose metabolism and its modulation by CB1R ligands evolve in the frontal cortex of young adult male Wistar rats, in the first 8 weeks of streptozotocin-induced type-1 diabetes (T1D). We report that frontocortical CB1R protein density was biphasically altered in the first month of T1D, which was accompanied with a reduction of resting glucose uptake ex vivo in acute frontocortical slices that was normalized after eight weeks in T1D. This early reduction of glucose uptake in slices was also restored by ex vivo treatment with both the non-selective CB1R agonists, WIN55212−2 (500 nM) and the CB1R-selective agonist, ACEA (3 μM) while it was exacerbated by the CB1R-selective antagonist, O-2050 (500 nM). These results suggest a gain-of-function for the cerebrocortical CB1Rs in the control of glucose uptake in diabetes. Although insulin and IGF-1 receptor protein densities remained unaffected, phosphorylated GSKα and GSKβ levels showed different profiles 2 and 8 weeks after T1D induction in the frontal cortex. Altogether, the biphasic response in frontocortical CB1R density within a month after T1D induction resolves previous controversial reports on forebrain CB1R levels in T1D rodent models. Furthermore, this study also hints that cannabinoids may be useful to alleviate impaired glucoregulation in the diabetic cortex