Obesity-related blood brain barrier changes in obese Zucker rats

The blood brain barrier (BBB) is the site of exchange between blood and the nervous tissue. Damage of it may impair physiological balance between blood stream and nervous tissue. Metabolic syndrome (MetS) is defined by several interconnected physiological, biochemical, and metabolic factors directly related to obesity. It increases the risk of atherosclerotic cardiovascular and cerebrovascular disease and of all cause mortality. Obese Zucker rats (OZRs), with a mutation in leptin receptor, represent a model of obesity exhibiting diabetes and moderate arterial hypertension. In OZRs hyperglycaemia, hyperinsulinaemia and hyperlipidaemia occur simultaneously. This work had characterized BBB and endothelial alterations of OZRs compared to their non-obese cohort lean Zucker rats (LZRs) for assessing the occurrence of an eventual cerebrovascular injury. Brains of male OZRs and LZRs of 12, 16 and 20 weeks were processed for the immunochemical and immunohistochemical detection of different BBB markers. The water channel protein Aquaporin-4 (AQP4) and the glucose transporter protein- 1 (GLUT1) involved in the glucose passage across the BBB endothelial cells were investigated. The expression of adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) was also assessed within cerebrovascular endothelium as a marker of inflammation. In intracerebral arteries of older OZRs, a decrease of lumen area with an increase of wall area was found. BBB of older OZRs revealed an augmented expression of AQP4 probably related to an edema formation. A downregulation of GLUT1 was observed in OZRs of 12 weeks of age. This may represent the adaptive reaction to prevent excessive glucose entering in neurons. On the contrary, in older OZRs an obvious increase in the expression of GLUT1 was found. These phenomena are probably related to vascular inflammation as confirmed by the increase of ICAM-1 and VCAM-1 expression in the endothelium of older OZRs. The above evidence shows that OZRs develope specific BBB changes. This could contribute to clarify the pathophysiology of nervous system damage reported in obese individuals. OZRs may represent an useful animal model for assessing the influence of obesity/MetS on the brain and the possible correlation of it with neurodegenerative disorders

Numerical modeling of fluid flow, heat, and mass transfer for similar and dissimilar laser welding of Ti-6Al-4V and Inconel 718

AbstractMost of the researches published on the numerical modeling of laser welding are looking at similar welding, mainly due to the difficulty of simulating the mixing phenomenon that occurs in dissimilar welding. Furthermore, numerical modeling of dissimilar laser welding of titanium and nickel alloys has been rarely reported in the literature. In this study, a 3D finite volume numerical model is proposed to simulate fluid flow, heat, and mass transfer for similar and dissimilar laser welding of Ti-6Al-4V and Inconel 718. The laser source was simulated by volumetric heat distribution, which considers the effects of keyhole and heat transfer on the workpiece. The heat source parameters were calibrated through preliminary experiments, by comparing the simulated and experimental weld pool shapes and dimensions. The model was used to simulate both homogenous and dissimilar laser weldings of Ti-6Al-4V and Inconel 718, and a systematic comparison was carried out through a number of selected experiments. The effects of three distinct levels of laser power (1.25 kW, 1.5 kW, 2.5 kW) on temperature distribution and velocity field in the welds pool were analyzed. Results highlighted the effects of Marangoni forces in the weld pool formation. Furthermore, in order to analyze the mass transfer phenomenon in dissimilar welding, species transfer equations were considered, demonstrating the important role played by the mass mixture in the weld pool formation. Finally, a high level of agreement between simulations and experiments—in terms of weld pool shape and dimensions—was observed in all cases analyzed. This proves the ability of the proposed numerical model to properly simulate both the similar and dissimilar welding of Ti-6Al-4V and Inconel 718 alloys

Identifying Variability in Process Performance Indicators

The performance perspective of business processes is concerned with the definition of performance requirements usually specified as a set of Process Performance Indicators (PPIs). Like other business process perspectives such as control-flow or data, there are cases in which PPIs are subject to variability. However, although the modelling of business process variability (BPV) has evolved significantly, there are very few contributions addressing the variability in the performance perspective of business processes. Modelling PPI variants with tools and techniques non-suitable for variability may generate redundant models, thus making it difficult its maintenance and future adaptations, also increasing possibility of errors in its managing. In this paper we present different cases of PPI variability detected as result of the analysis of several processes where BPV is present. Based on an existent metamodel used for defining PPIs over BPs, we propose its formal extension that allows the definition of PPI variability according to the cases identified.Ministerio de Economía y Competitividad TIN2015-70560-RJunta de Andalucía P12-TIC-1867Junta de Andalucía P10-TIC-590

Learning through Fashion Archives: the case of the Gianfranco Ferré Archive

According to the recent debates about the role of fashion in museums and universities [1], in the 1980s and more specifically in the 1990s [2], the focus on fashion archives’ rethinking between management and research practice has moved from a passive inventory of garments and records to a system of social constructs, to develop a sense of identity and community. Considered a place of knowledge, memory, and power, fashion archives’ ability to represent socio-cultural history through clothing has been recognized alongside the consciousness of the relevance of fashion collections conserved in museums and archives as a barometer of cultural values and expressions. In the last decades, fashion has strengthened its role in modern culture and brands have become finally aware of the potential that heritage and a long-standing tradition have, also for economical purposes. In fact, brand heritage emerges as a concept within the marketing discipline, which suggests that heritage elements may be used as evidence to support claims about the status of a brand or its products, especially concerning concepts such as authenticity or pioneership. In view of this study, the paper will present Gianfranco Ferré Archive’s use and interpretation with a focus on the dissemination of culture linked to the material and non-material heritage of the designer’s production, such as lectures, visits, conferences, specific workshops and support for thesis and personal research. The essay will put special attention to the pedagogical outcomes of using archives as primary research material when studying or designing. Now attached to the Politecnico di Milano, Gianfranco Ferré Archive is more than before devoted to the exploration of a pedagogical interpretation of the archive to empower students and researchers through a multivocal tool that is both theoretical and physical. Moreover, in this case, the functions of the archive perfectly respect and pay homage to the spirit of the designer himself that believed in the potential of dissemination, teaching, and increased use of the heritage, documented in a series of lectures in the book Lessons in Fashion (2009). Inspired by the visionary archive-based study approach of the designer, Gianfranco Ferré Research Centre today combines the conservation of its patrimony with the activation of new training paths capable of transferring and updating the memory of artisanal expertise and techniques that can become a new tool for innovation in the design and technology field

Chromatic Vocabulary: the color design research according to Gianfranco Ferré

The study of color in the fashion design field has been much debated. From being a source of inspiration for designers, the use of color acquired an evident relevance as an element capable of defining the perceptive variations and intrinsic meanings established in the dialogic relationship between the material and its cultural dimension. Consequently, it becomes a communicative and visual vehicle of great impact, defining personal and social identities and conveying messages that address today to a larger audience. In its relationship with matter, we can notice that color takes on a stronger semantic connotation. It is a linguistic element that, particularly in fashion, contributes to the overall narrative of creation that finds the codes of its language in the identity of the individual but also in the socio-cultural context in which it is immersed. Fashion and cultural studies have now shown that if fashion is an expression of the self, color is actually a tool for constructing a personal statement and expressing it. Therefore, color - as an expressive code and bearer of shared socio-cultural values - strongly influences the value, design and identity construction of fashion itself. One fashion designer who has always distinguished himself for his rigorous and complex creative process in the use of color was Gianfranco Ferré. His teaching and design method was expressed through the contamination of three variables– color, shape and matter– declined in a plurality of models and formats that express desire, dream and luxury, without losing any connection with the real and material world. For Ferré, the use of color plays a primary role, in realizing unique and irreproducible combinations of form and substance, for conveying precise feelings and emotions, enhancing the body of the wearer. For this reason, Ferré considers the choice of colors and their shades an “intentional” act born at the same time as the idea of the dress itself and that guarantees coherence and identity among seasons and collections. Due to the uniqueness of his creative process, which represents still nowadays a multifaceted material of study, this paper aims to analyze and investigate the role of color in Gianfranco Ferré’s method and how it became effectively part of his lexicon. Case studies, practical examples and lectures held by the designer will show the relevance of the color and its articulation in his production, from the influence of his sources of inspiration to his iconic “white shirt” whose color justifies the existence itself of the shirt as a universal piece where tradition and innovation meet

Mechanical Behavior of Aluminum Sandwiches Made by Laser Welding

AbstractAluminium sandwiches are interesting subcomponents for lightweight structures applied in rail cars for high speed. A method to realize aluminium sandwiches consists in welding sheets to elementary extruded profiles. Laser welding is the production technology that promises the better features in terms of quality and productivity. Thanks to concentrate energy and very small Heat Input (HI), the laser welding process minimizing the wide of the Heat Affected Zone (HAZ) and the distortions and allow high welding speed. In this work laser technique was applied to join a mock-up of a large aluminium sandwich panel. The mechanical behaviour of the assembled panel was investigated in the two main orthogonal direction of load by four point bending tests.Elastic-plastic FE Analysis confirm the results of bending tests and it is possible to appreciate the quality of welding process that produce joint strength and ductile. In fact in the both load direction it's possible to evaluate the plastic deformation on the welded beam without visible cracks in the welds. The data about the mechanical features of the welds for the FE analysis, about the 80% of the base materials, was achieved by tensile test on elementary but joint. The SEM fractography of the butt joint shows dimples in all the surface of the fracture, confirming the good quality and ductility of welds also in presence of some little micro porosity.The present paper is based on the achievements of the TRAIN Consortium within the research project SIFEG (Integrated freight transport rail-road), granted by the Italian Ministry of Economic Development for the Program “Industria 2015 – Mobilità Sostenibile”

Process Optimization in Laser Welding of IN792 DS Superalloy

Ni-base superalloys are employed to produce parts of aeronautic engines, space vehicles and power plants. During the production process or lifetime of components, cracks may occur which affect their performance. Reliable repairs can be carried out through high-energy density welding techniques. This work investigated laser welding of the directionally solidified IN792 DS superalloy. The characteristics of the original material and their evolution in the base metal, heat-affected zone and melt zone after laser welding in different conditions and post-welding heat treatment were investigated through micro-hardness tests, light and scanning electron microscopy observations. The study allowed to optimize the process parameters and post-welding heat treatment, obtaining joints without macro-defects, such as cracks and pores, and with properties and microstructures of the melt zone like those of base metal

A comparative analysis between material extrusion and other additive manufacturing techniques: Defects, microstructure and corrosion behavior in nickel alloy 625

Additive manufacturing (AM) is becoming a consolidated reality for nickel alloys production in recent years. Among the several technologies available, material extrusion (MEX) is gaining industrial interest. However, its qualification is fundamental to achieve high-value applications. In this work, Ni alloy 625 produced using different AM techniques was comparatively analyzed in terms of process-related defects, microstructure and corrosion behavior. Specimens manufactured via MEX, laser powder bed fusion (PBF-LB), and directed energy deposition (DED-LB) were investigated. The MEX-produced samples showed micropores and periodically-arranged elongated macro-defects. These were analyzed in terms of image analysis and micro computed tomography. The resulting void 3D structure was mainly constituted by a grid of hollow channels, mimicking the ± 45° scanning strategy adopted. The microstructure was mainly constituted by Mo-, Nb- and Si-rich precipitates in a Ni matrix. The second phases had a blocky morphology in the core part of the material. Conversely, an elongated shape following the grain boundaries was detected in the contour. These microstructural variations impacted on the response of the alloy in an aggressive environment (ASTM G28-A). In fact, the core underwent a localized attack, whilst the contour part was characterized by a negligible effect, as assessed in the PBF-LB and DED-LB-processed specimens