Multiscale Composites: Assessment of a Feasible Manufacturing Process

A very interesting field of research on advanced composite materials is the possibility to integrate new functionalities and specific improvements acting on the matrix of the composite by means of a nanocharged resin. In this way, the composite becomes a so-called "multiscale composite" in which the different phases change from nano to macro scale. For example, the incorporation of nanoscale conductive fillers with intrinsically high electrical conductivity could allow a tailoring of this property for the final material. The properties of carbon nanotubes (CNT) make them an effective candidate as fillers in polymer composite systems to obtain ultralight structural materials with advanced electrical and thermal characteristics. Nevertheless, several problems are related to the distribution in the matrix and to the processability of the systems filled with CNT. Existing liquid molding processes such as resin transfer molding (RTM) and vacuum-assisted resin transfer molding (VARTM) can be adapted to produce carbon fiber reinforced polymer (CFRP) impregnated with CNT nanofilled resins. Unfortunately, the loading of more than 0.3-0.5% of CNT can lead to high resin viscosities that are unacceptable for such kind of processes. In addition to the viscosity issues that are related to the high CNT content, a filtration effect of the nanofillers caused by the fibrous medium may also lead to inadequate final component quality. This work describes the development of an effective manufacturing process of a fiber-reinforced multiscale composite panel, with a tetra-functional epoxy matrix loaded with carbon nanotubes to increase its electrical properties and with GPOSS to increase its resistance to fire. A first approach has been attempted with a traditional liquid infusion process. As already anticipated, this technique has shown considerable difficulties related both to the low level of impregnation achieved, due to the high viscosity of the resin, and to the filtration effects of the dispersed nanocharges. To overcome these problems, an opportunely modified process based on a sort of film infusion has been proposed. This modification has given an acceptable result in terms of impregnation and morphological arrangement of CNTs in nanofilled CFRP. Finally, the developed infiltration technique has been tested for the manufacture of a carbon fiber-reinforced panel with a more complex shape

Requirements for the Design of Flexible and Changeable Manufacturing and Assembly Systems: A SME-survey☆

Abstract Increasingly complex market dynamics due to unpredictable forecasts and shorter innovation cycles require maximum flexibility from production companies and their manufacturing systems. A manufacturing system should not only produce high-quality products at the lowest possible price; it should also be able to react quickly to market changes and consumers preferences. After the implementation in large enterprises belonging to the automotive sector and other related sectors, the concept of flexibility and changeability has been introduced in small and medium-sized enterprises (SME). In recent years, the concept of flexibility and changeability was object of research and industry. Current research in manufacturing pays great attention to flexibility and changeability in manufacturing and assembly systems. Therefore, research and investigations are needed to analyze the requirements for the design of flexible and changeable manufacturing and assembly systems in SMEs in order to define simple and practically suitable design guidelines. This research analyzes the nature of environmental changes, which SMEs are currently facing, due to a questionnaire-based survey. This research paper summarizes the results of the survey, executed with 27 SME companies in North Italy, showing the main requirements for the design of flexible and changeable manufacturing and assembly systems

Morphological and molecular characterization of three new parastenocarididae (Copepoda: Harpacticoida) from caves in Southern Italy

We describe three new parastenocaridid: Cottarellicaris sanctiangeli Bruno & Cottarelli sp. nov., Stammericaris vincentimariae Bruno & Cottarelli sp. nov. and Proserpinicars specincola Bruno & Cottarelli sp. nov., collected in the pools of five different caves located in Calabria (Southern Italy). We conducted a phylogenetic analysis based on the mitochondrial COI and ribosomal 18S sequences of C. sanctiangeli sp. nov. and S. vincentimariae sp. nov., and of four more species of Stammericaris and one Proserpinicaris available from literature. Based on the molecular study, the specimens of C. sanctiangeli sp. nov. are clearly separated from the species belonging to the closely-related genus Stammericaris. The morphological and molecular data indicate that the genera belonging to the two subfamilies Parastenocaridinae and Fontinalicaridinae form two monophyletic and distinct clades, thus supporting their status. We also provide insights on the genus Proserpinicaris based on morphological data only; in particular, the most important synapomorphic character of the genus, i.e., the taxonomic value of the hyaline structure inserted on the anterior surface of the male leg 4 basis, is discussed based on the development of the P4 endopod, as observed in the last copepodid stage of some species of this genus. Finally, we widen the biogeographic and ecological knowledge of the three genera

THE VIRTUAL BATCAVE: A PROJECT FOR THE SAFEGUARD OF A UNESCO WHL FRAGILE ECOSYSTEM

Abstract. This abstract illustrates an interdisciplinary research project which focuses on the study, conservation and enhancement, through 3D digitization and virtual fruition, of an asset of great naturalistic, historical and ethnoanthropological value: Grotta dei Pipistrelli of Pantalica Nature Reserve (Sortino, SR). The cave (located in the Calcinara necropolis) is characterized by a great beauty as well as by a high cultural relevance and a remarkable scientific importance. In 2005, it awarded the UNESCO World Heritage title for its high historic, archaeological and speleological profile. Despite the site is being studied by specialists in chiropterofauna, nowadays there is not a comprehensive and reliable documentation of the plano-altimetric morphology of the cave, able to constitute a 3D database of essential information (e.g. morphological, geological, textural and wildlife information) for current and future studies, and to preserve the memory of this fragile ecosystem. The process of 3D digitization aims to create a model of the cave that allows us to enjoy this place, to explore it and to closely understand it in order to limit the anthropic pressure caused by visitors on the real site. Consequently, it is proposed the creation of a virtual environment, as a reproduction of the real one, which can be enjoyed by all categories of users.</p

Optimization of transgene action at the post-transcriptional level: high quality parthenocarpic fruits in industrial tomatoes

Background: Genetic engineering of parthenocarpy confers to horticultural plants the ability toproduce fruits under environmental conditions that curtail fruit productivity and quality. TheDefH9-iaaM transgene, whose predicted action is to confer auxin synthesis specifically in theplacenta, ovules and derived tissues, has been shown to confer parthenocarpy to several plantspecies (tobacco, eggplant, tomato) and varieties.Results: UC82 tomato plants, a typical cultivar used by the processing industry, transgenic for theDefH9-iaaM gene produce parthenocarpic fruits that are malformed. UC82 plants transgenic forthe DefH9-RI-iaaM, a DefH9-iaaM derivative gene modified in its 5'ULR by replacing 53 nucleotidesimmediately upstream of the AUG initiation codon with an 87 nucleotides-long sequence derivedfrom the rolA intron sequence, produce parthenocarpic fruits of high quality. In an in vitro translationsystem, the iaaM mRNA, modified in its 5'ULR is translated 3\u20134 times less efficiently than theoriginal transcript. An optimal expressivity of parthenocarpy correlates with a reduced transgenemRNA steady state level in DefH9-RI-iaaM flower buds in comparison to DefH9-iaaM flower buds.Consistent with the known function of the iaaM gene, flower buds transgenic for the DefH9-RI-iaaMgene contain ten times more IAA than control untransformed flower buds, but five times less thanDefH9-iaaM flower buds.Conclusions:: By using an auxin biosynthesis transgene downregulated at the post-transcriptionallevel, an optimal expressivity of parthenocarpy has been achieved in a genetic background notsuitable for the original transgene. Thus, the method allows the generation of a wider range ofexpressivity of the desired trait in transgenic plants

Modeling, simulation and control of a 4WD electric vehicle with in-wheel motors

A relatively new technology for the electric vehicles considers the use of brushless permanent magnet motors directly connected to the car wheels (in-wheel motors or hub motors). In order to evaluate the performance that can be obtained, a complete dynamic model of a four-wheel drive (4WD) electric vehicle equipped with four in-wheel motors is developed and a correspondent parametric simulator is implemented in Matlab/Simulink™. The simulator is also employed for designing, testing and comparing various control logics which reproduce the handling behavior of a real vehicle

Effects of microalloying on an innovative quenched and tempered plastic mold steel

presentazione orale al TMS 2008 Annual Meeting & Exhibition (TMS2008), New Orleans, LA, USA, 9/3/2008 - 13/3/200

Influence of the microstructure on fatigue and fracture toughness properties of large heat-treated mold steels

The standard ISO 1.2738 medium-carbon low-alloy steel has long been used to fabricate plastic molds for injection molding of large automotive components, such as bumpers and dashboards. These molds are usually machined from large pre-hardened steel blooms. Due to the bloom size, the heat treatment yields mixed microstructures, continuously varying from surface to core. Negative events (such as microcracks due to improper weld bed deposition or incomplete extraction of already formed plastic objects) or too large thermal/mechanical stresses can conceivably cause mold failure during service due to the low fracture toughness and fatigue resistance typically encountered in large slack quenched and tempered ISO 1.2738 steel blooms. Alternative steel grades, including both non-standard microalloyed steels, designed for the same production process, and precipitation hardening steels, have recently been proposed by steelworks. However, the fracture toughness and the fatigue properties of these steels, and hence their response during the service, are not well known. Results of an experimental campaign to assess the fracture toughness and fatigue properties, as well as the basic mechanical properties, of a microalloyed and a precipitation hardening plastic mold steel blooms are presented and commented, also in respect to the results previously obtained by two commercial ISO 1.2738 ones. Experimental results show that these steels generally exhibit low fracture toughness values; in the traditional quenched and tempered bloom steels the brittleness may be caused both by the presence of mixed microstructures and by grain boundaries segregation, while in the precipitation hardened one the brittleness probably stems from the precipitation phenomena. This study suggests that microalloyed and precipitation hardening steels may be used to produce large plastic mold, yet the fracture toughness still remains the most critical propert

Impact of Circadian Desynchrony on Spermatogenesis: A Mini Review

The purpose of this mini review is to provide data about pre-clinical and clinical evidence exploring the impact of circadian desynchrony on spermatogenesis. Several lines of evidence exist demonstrating that disruption of circadian rhythms may interfere with male fertility. Experimental knock-out or knock-down of clock genes, physiologically involved in the regulation of circadian rhythms, are associated with impairments of fertility pathways in both animal and human models. Moreover, disruption of circadian rhythms, due to reduction of sleep duration and/or alteration of its architecture can negatively interfere in humans with circulating levels of male sexual hormones as well as with semen parameters. Unfortunately, current evidence remains low due to study heterogeneity

Epigenetic Matters: The Link between Early Nutrition, Microbiome, And Long-term Health Development

Epigenetic modifications are among the most important mechanisms by which environmental factors can influence early cellular differentiation and create new phenotypic traits during pregnancy and within the neonatal period without altering the deoxyribonucleic acid sequence. A number of antenatal and postnatal factors, such as maternal and neonatal nutrition, pollutant exposure, and the composition of microbiota, contribute to the establishment of epigenetic changes that can not only modulate the individual adaptation to the environment but also have an influence on lifelong health and disease by modifying inflammatory molecular pathways and the immune response. Postnatal intestinal colonization, in turn determined by maternal flora, mode of delivery, early skin-to-skin contact and neonatal diet, leads to specific epigenetic signatures that can affect the barrier properties of gut mucosa and their protective role against later insults, thus potentially predisposing to the development of late-onset inflammatory diseases. The aim of this review is to outline the epigenetic mechanisms of programming and development acting within early-life stages and to examine in detail the role of maternal and neonatal nutrition, microbiota composition, and other environmental factors in determining epigenetic changes and their short-and long-term effects