CDRsp - Comunicações em conferências internacionais
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- Optimizing regions for characterization of thermal images in medical applicationsPublication . Duarte, A.; Carrão, L.; Espanha, M.; Viana, T.; Freitas, D.; Bártolo, P.; Faria, P.; Almeida, H.Biomedical techniques and applications are being developed and placed at the service of clinicians. An example is medical thermography which is being used more often in the detection of certain diseases and also in pain distribution. Current thermography processing software has some limitations mainly because it is developed for general applications and doesn't allow the identification of a Region Of Interest (ROI) with a specific anatomic shape. In this research, a computational application was developed in order to aid in the characterization of thermal images. The limitations of existing software applications was overcome by designing an application that allows choosing any ROI, independently of its geometric shape, making the analysis, processing and comparison of different thermal images, easier to be used by the medical community.
- Soccer sprint and agility are similar between pre- and postpubescent boys, when ball is consideredPublication . Morouço, P.G.; Dias, R.; Menino, V.Introduction Scientific evidence suggests that specific physiological demands and anthropometrical prerequisites result in the selection of young players based onenhanced physiological performances and anthropometricaladvantage (1). How-ever, the competitive demands are not the same in youth categories, inducing different physical and physiological profiles from those of adult players (2). The purpose of the present study was to analyze possible differences in speed, agility and jump height of pre- and postpubescent soccer players.
- Strength or technique: What should be trained to increase swimming speed?Publication . Morouço, P.G.; Marinho, D.A.; Marques, M.C.Introdution Swimming speed is both dependent on strength and technique. Indeed, the balance between these two major factors may explain the success or failure in competitive events. However, competitive events vary enormously in terms of distance, and therefore time and intensity. Thus, an optimal level of strength is essential for successful performance in swimming (1), varying according to the distance to be swam (2). But how can swimming coaches track the balance between these two factors? And how can be identified if the swimmer must focus in one of them, in detriment of the other?
- The influence of knowledge management on the result of innovation of companies in the mold industriesPublication . Ferreira, Vítor Hugo Santos; Marques, Alzira Maria Ascensão; Espírito Santo, Pedro Manuel do; Silva, Sara Fernandes daIn today's business world, knowledge and innovation are key factors for the success of organizations. Knowledge stock alone does not generate a competitive advantage to companies, but the way it is used might create it. It is through the wide network of relationships that involves the organization that innovations emerge. These two concepts are intertwined, since for the innovation process to be successful, there must first be an effective knowledge management, which involves knowledge acquisition, application and sharing. In this context and based on a sample of 36 companies in the mold making sector in Portugal (one industry where Portugal is the 8th top producer in the world), a confirmatory research work was carried out with the aim of studying the impact of knowledge management on innovation performance. For this purpose, we used a quantitative methodology based on a survey. Through the estimation of a structural equations model, using SmartPLS software, we found that knowledge acquisition has a positive influence on knowledge sharing, which in turn is positively reflected in its application, which positively impacts innovation in performance in Portuguese plastic injection mold making companies-these results are in line with similar studies carried out in different contexts. Consequently, knowledge, considered as an intangible asset, must be managed effectively and efficiently, in order to create value through innovation, a determinant of competitiveness in an activity sector that creates customized solutions for its customers. Despite of the small sample size, these results highlight the importance of effectively managing the acquisition.
- How knowledge sharing mediates the effects of internal marketing on customer orientationPublication . Espírito Santo, Pedro Manuel do; Ferreira, Vítor Hugo Santos; Marques, Alzira Maria AscensãoA growing body of research has demonstrated the growing importance given to two areas of business management: internal marketing and knowledge management. Nevertheless, these seldom areas are considered together. This paper explores the importance of knowledge sharing as a mediating variable in the relationship between internal and external marketing. Thus, our research presents an investigation model where the influence of tacit knowledge sharing and explicit knowledge sharing are presented. The data of this research was collected from the employees of a company in the logistics sector, through a face-to-face questionnaire. The proposed research hypotheses were tested empirically through structural equation modeling (PLS-PM) with a bootstrapping procedure. The results demonstrate that internal marketing has a positive effect on knowledge sharing and, consequently, on customer orientation. In this sense, through this paper, managers can verify the importance of knowledge sharing (tacit and explicit) in leveraging the effects of internal marketing in customer orientation.
- PCL/Eggshell Scaffolds for Bone RegenerationPublication . Viana, Tânia; Biscaia, Sara; Henrique, Almeida A.; Bártolo, Paulo J.; Bártolo, Paulo J.Eggshell (ES) is one of the most common biomaterials in nature. For instance, the ES represents 11% of the total weight of a hen’s egg and it is composed of calcium carbonate, magnesium carbonate, tricalcium phosphate and organic matter. Hen ES are also a major waste product of the food industry worldwide. Recently, ES have been used for many applications such as coating pigments for inkjet printing paper, catalyst for biodiesel synthesis, bio-fillers for polymer composites and matrix lipase immobilization. It is also considered a natural biomaterial with high potential for the synthesis of calcium enriched implants that may be applied in tissue engineering applications, such as bone regeneration. The aim of this research regards the production of poly(ε-caprolactone) (PCL) scaffolds enriched with hen ES powder for bone regeneration applications, using an extrusion-based process called Dual-Bioextruder. The main objective is to investigate the influence of the addition of ES powder on the PCL matrix. For this purpose the structures were characterised regarding morphological and chemical properties. Morphological images of the PCL scaffolds enriched with hen ES, demonstrated the interconnectivity of the pores within the scaffold and revealed that the addition of the ES powder combined with the screw rotation velocity has a large influence on the resulting filament diameter and consequently on the porosity of the scaffolds.
- Topological Shear Stress Optimisation of Micro-CT Based ScaffoldsPublication . Almeida, Henrique A.; Bártolo, Paulo J.Additive manufacturing technologies are being used to fabricate scaffolds with controlled architecture for tissue engineering applications. These technologies combined with computer-aided design systems enable to produce three-dimensional structures layer-by-layer in a multitude of materials. Actual prediction of the effective mechanical properties of scaffolds produced by Additive manufacturing systems, is very important for tissue engineering applications. One of the existing computer based techniques for scaffold design is topological optimisation. The goal of topological optimisation is to find the best use of material for a body that is subjected to either a single load or a multiple load distribution. This paper proposes a topological optimisation scheme based on existing micro-CT data in order to obtain the ideal topological architectures of scaffolds, maximising its mechanical behaviour under shear stress solicitations. This approach is based on micro-CT data of real biological tissues to create the loading (shear stress) and constraint surfaces of the scaffold during the topological optimisation process. This particular topological optimisation scheme uses the surface boundaries to produce novel models with different characteristics, which are different from the initial micro-CT models. This approach enables to produce valid biomimetic scaffold topologies for tissue engineering applications.
- Effects of Scaffold Electrical Properties on Electric Field Delivery in BioreactorsPublication . Meneses, João; Fernandes, Sofia R.; Alves, Nuno; Pascoal-Faria, Paula; Miranda, Pedro CavaleiroIn tissue engineering, cell culture scaffolds have been widely used in combination with electrical stimulation to promote multiple cellular outcomes, like differentiation and proliferation. Nevertheless, the influence of scaffolds on the electric field delivered inside a bioreactor is often ignored and requires a deeper study. By performing numerical analysis in a capacitively coupled setup, this work aimed to predict the effects of the scaffold presence on the electric field, considering multiple combinations of scaffold and culture medium electrical properties. We concluded that the effect of the scaffold on the electric field in the surrounding culture medium was determined by the difference in electrical conductivity of these two materials. The numerical simulations pointed to significant variations in local electric field patterns, which could lead to different cellular outcomes and confound the interpretation of the experimental results.
- Role of Anisotropy in Tissue EngineeringPublication . Mitchell, Geoffrey R.; Tojeira, AnaTissue engineering is a highly interdisciplinary field that requires the integrated expertise of clinicians, cell biologists, engineers and material scientists, to make progress in the development and deployment of biological substitutes that restore, maintain, or improve tissue function. The purpose is to provide the opportunities for tissue regeneration and organ replacement. Key advances in biological materials especially in the area of stem cells; growth and differentiation factors generate realistic opportunities to create tissues in the laboratory using an engineered extracellular matrix or scaffold and biologically active molecules. The scaffold acts as an artificial extracellular matrix and it needs to mimic the chemical composition and physical architecture of natural extracellular matrix to facilitate cell adhesion, proliferation, differentiation and new tissue formation. In this contribution we review the role of the scaffold system in promoting cell adhesion, proliferation and differentiation with respect to the anisotropic nature of the scaffold system. We address both the anisotropy which may exist at a microscopic or mesoscopic scale, for example the shape of pores as well as the molecular level interactions which may arise in a scaffold containing a molecular organization with a preferred orientation which may have been induced during the processing procedures used to prepare the scaffold. Of course some approaches to the preparation of scaffolds systems are inherently anisotropic, for example the wide-spread utilization of meshes prepared by electrospinning. In other words although the overall scaffold is isotropic, the basic elements in terms of an electrospun fibre is highly anisotropic in terms of its external form and possibly in terms of its internal structure. By reviewing the possible advantages of the inclusion of anisotropic elements in the scaffold we add to the knowledge base which allows scaffolds design to be optimised for specific tissue growth.
- SANS/WANS Time-resolving Neutron Scattering Studiesof Polymer Phase Transitions Using NIMRODPublication . Mitchell, Geoffrey Robert; Bowron, Daniel; Mateus, Artur; Bártolo, Paulo; Gkourmpis, Thomas; Phomphrai, Khamphee; Lopez, Daniel; Davis, FredABSTRACT We use new neutron scattering instrumentation to follow in a single quantitative time-resolving experiment, the three key scales of structural development which accompany the crystallisation of synthetic polymers. These length scales span 3 orders of magnitude of the scattering vector. The study of polymer crystallisation dates back to the pioneering experiments of Keller and others who discovered the chain-folded nature of the thin lamellae crystals which are normally found in synthetic polymers. The inherent connectivity of polymers makes their crystallisation a multiscale transformation. Much understanding has developed over the intervening fifty years but the process has remained something of a mystery. There are three key length scales. The chain folded lamellar thickness is ∼ 10nm, the crystal unit cell is ∼ 1nm and the detail of the chain conformation is ∼ 0.1nm. In previous work these length scales have been addressed using different instrumention or were coupled using compromised geometries. More recently researchers have attempted to exploit coupled time-resolved small-angle and wide-angle x-ray experiments. These turned out to be challenging experiments much related to the challenge of placing the scattering intensity on an absolute scale. However, they did stimulate the possibility of new phenomena in the very early stages of crystallisation. Although there is now considerable doubt on such experiments, they drew attention to the basic question as to the process of crystallisation in long chain molecules. We have used NIMROD on the second target station at ISIS to follow all three length scales in a time-resolving manner for poly(e-caprolactone). The technique can provide a single set of data from 0.01 to 100Å-1 on the same vertical scale. We present the results using a multiple scale model of the crystallisation process in polymers to analyse the results.