600 research outputs found

    Redesign of machine component in polymeric matrix composite towards increased productivity

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    This work is focused in the maximization of the acceleration a 2D Industrial Laser Cutting Machine (ILCM). The changes to be implemented are centered in the replacement of a metallic critical component: the gantry. This component largely influences precision and maximum acceleration. Finite Elements Analysis was performed to the current metallic part. From this analysis the maximum allowed deformations were established. A replacement composite component capable of an equally valid behavior was designed in carbon fiber. To establish the maximum increase in acceleration that does not lead to precision losses, the working conditions were simulated and the acceleration to which the component was subjected to was varied. The variation of the thickness of layers with different orientations and locations in the part allowed for the understanding of how the mass varies along with the maximum possible acceleration. This analysis, asides with considering the maximum force allowed by the linear motor that is responsible by the gantry motion, establishes the limit in terms of maximum acceleration of the machine. An increase of 22% in the maximum acceleration while maintaining the precision is possible due to the higher specific rigidity of composite materials and the use of an optimization heuristic

    Redesign of an industrial laser cutting machine’s gantry in composite material

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    This work is focused in the design stage of a composite structure intended to replace a metallic critical component in a 2D Industrial Laser Cutting Machine (ILCM). The component is the gantry, largely responsible for most of the ILCM’s characteristics. These include precision and maximum acceleration, which are critical. The dimensioning of the component is initially performed based on analytical models, but latter stages use the numerical capabilities of Finite Elements Method. In the end it is possible to take advantage of the higher specific rigidity of composite materials to increase the maximum acceleration that the machine allows for while maintaining the precision.(undefined

    Synthesis of novel 2-aryl-3-(2-morpholinoethyl)-1,3-thiazinan-4-ones via ultrasound irradiation

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    This study describes the synthesis of fourteen thiazinanones from a multicomponent reaction of 2-morpholinoehtylamine (as primary amine), arenealdehydes (as carbonyl compound) and the mercaptopropionic acid using both conventional (thermal heating) and ultrasound methodologies. Through thermal heating methodology, the thiazinanones were obtained in 49 to 97% yields for 16 hours and through sonochemistry methodology, the reaction time was reduced for 25 minutes with yields 41 to 88%. The full identification and characterization of unpublished heterocycles were achieved by proton (1H) and carbon 13 (13C) nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry and infrared. Some of them were also characterized by elemental analysis27611091115CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DO RIO GRANDE DO SUL - FAPERGS307330/2012-5Sem informação2013/18203-511/2068-

    Ohmic heating in a food application: quality evaluation of cloudberry jam

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    New techniques for food processing are areas of interest for the food industry and ohmic heating is an example of a new technique where there are many possible applications in the food area. The aim of this work was to characterize and compare quality aspects of high quality cloudberry jam with 70 weight-% berries produced on one hand by traditional batch processing technique and on the other hand by ohmic heating in a continuous process. Sensory analysis was performed on the two jams by a trained panel. In order to investigate the consumer opinions in different countries a consumer study was performed including 402 consumers from the four countries Sweden, Portugal, Ireland and Slovakia. Rheological properties of the jam were also measured. The results showed that there were no significant differences for any of the sensory attributes between the jam produced by traditional technique and the jam produced by ohmic heating. The results from the consumer study showed that in all four countries, the appearance, odour, flavour, texture, aftertaste and overall quality of both jams were liked to the same extent. However, differences in liking cloudberry jam differed between the participating countries. The Swedish and the Portuguese consumers were in general giving higher scores on the liking of the cloudberry jams than the Slovakian and Irish consumers. There were no differences found between the two jams according to the rheological properties of the samples. The results indicated that it was possible to maintain the same quality of cloudberry jam produced by ohmic heating as of cloudberry jam produced in a traditional way

    New alternatives to milk from pulses: digestibility and bioactivity

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    There is a high demand for milk substitutes other than soy beverages for different reasons, from health to ethic grounds. However, plant based current market offers are essentially poor in protein content (less than 1.5% against the 3.5% in milk). The obvious choice is the use of pulses with high total protein on seeds, but a major issue hampers their production - a beany flavour. This is mitigated by the right processing technology, which also enhances the beverage nutritional quality. Beverages produced from chickpea, lupin and its (50/50) mixture were submitted to in vitro gastrointestinal digestion static method (Brodkorb et al., 2019). Results on bioaccessibility of protein, carbohydrates, starch, minerals and phytate, as well as glycaemic index and bioactivity (anti-cancer and anti-inflammatory) were determined. Grain legumes contain slow-release carbohydrates like starch, present on the chickpea, but only residual on the lupin seeds. This was used to enhance flavour as the addition of enzymes, such as α-amylase and amyloglucosidase, during beverage fabrication process, which increases the pulse beverage´s digestibility, enhancing the sweeter mouthfeel by starch hydrolysis, releasing glucose rapidly to the bloodstream and leading to a higher GI. This was evidenced in chickpea based beverages with both enzymes (85.3), with only amyloglucosidase (78.9) and with only α-amylase (64.8), when compared to the lower glycaemic index of chickpea beverage (56.9). As known, the presence of phytates may reduce bioavailability of minerals as a mineral complex which is insoluble at the physiological pH of the intestine, nevertheless, even all beverage´s digesta showed twice as much its beverage phytic acid content, the lupin beverage digesta evidenced significantly the higher levels on Na, Mg, P and Mn contents. In what bioactivity is concerned, the lupin-based beverage evidenced the inhibition of colon cells migration and the efficient inhibition of the metalloproteinases (MMP´s), which are implicated in colorectal cancer metastatic progression, earlier attributed to the lupin peptides activity (Lima et al., 2016). One of the main conclusions, is the considerable increment on bioactivity of the produced peptides during protein digestion in the gut, which has been evidenced and can be used as an argument for the marketing of these pulse beveragesN/

    Determination of frutooligosaccharides adsorption parameters using ion-exchange resins

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    Fructooligosaccharides (FOS) are non-digestible sugars that beneficially affect the host by stimulating the growth of specific bacteria in the colon. In large scale, FOS can be produced from sucrose by fermentation. The fermentative broth obtained from this process is a complex mixture of salts and sugars. These sugar mixtures include FOS, namely kestose (GF2), nystose (GF3) and fructo-furanosylnystose (GF4), but also fructose, glucose and sucrose that must be separated. The major challenge when designing the downstream separation process is the choice of an efficient ion-exchange resin. Therefore, adsorption isotherms of the different compounds on a mixture are an important parameter to consider when selecting the resin. Moreover, salts and other sugars present in the mixture will influence the adsorption. In view of this, in the present work adsorption isotherms of FOS, both from fermentative broths and pure mixtures, were determined for several poly(styrene-co-divinylbenzene) commercial resins in the sodium and calcium forms. A static adsorption-desorption method was used to determine the equilibrium adsorptions. The adsorption isotherms for FOS were appropriately fitted using linear regression models. Since FOS separation is mainly based on size exclusion, GF2 was found to be the most adsorbed sugar in all resins, followed by GF3 and finally GF4. Results demonstrated that there are no significant differences between the adsorption of a pure mixture of FOS and a fermentative broth using the studied commercial calcium resins. However, this was not observed for the sodium form resin. In this later case, the sugars from the fermentative broths were found to be more adsorbed than from the pure mixtures. Results gathered in this study clearly demonstrated the importance of determining the adsorption parameters using real fermentative broths instead of pure mixtures, as the presence of other sugars and salts can influence in the adsorption

    Mechanical joining methods for additive manufactured assembly tools

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    The use of additive manufacturing (AM) processes is growing in the manufacturing industry. One application with great potential for using these processes is the manufacture of assembly tools for a high-ly competitive markets, such as the automotive industry. A critical aspect of the assembly tool design is its capability to incorporate modifications even at a late stage of its development in very short time. In many cases, these modifications are achieved using metal inserts in the polymeric tool, which allow to add new geometric features. This capability increases the usefulness and versatility of components produced by AM and compensate for potential shortcomings of using additive mate-rials. The purpose of this paper is to evaluate the potential use of accessories in additive manufactured com-ponents. In addition, the effect of different percentages of infill tool material on the joining quality of accesso-ries is evaluated. This is done by performing a screw pull-out test on a ABS ESD-7 part, produced by fused deposition modelling. The following different joining solutions were compared and studied in this work: em-bedded inserts, glue, heating processes, pressure (Tap-in) and creation of threads, such as, printing the thread directly and machining the thread onto the material.Programa Operacional Competitividade e Internacionalização - COMPETE 2020, Projeto nº 002814, Ref. POCI-01-0247-FEDER-002814 entre a Univ. do Minho e a Bosc
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