1,851 research outputs found

    Damaging micromechanisms in an as cast ferritic and a ferritized ductile cast iron

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    Mechanical behavior and damaging micromechanisms in Ductile Cast Irons (DCIs) are strongly effected by matrix microstructure (e.g., phases volume fraction, grains size and grain distribution) and graphite nodules morphology peculiarities (e.g., nodularity level, nodule size, nodule count, etc.). The influence of the graphite nodules depends on both the matrix microstructure and the loading conditions (e.g., quasi-static, dynamic or cyclic loadings). According to the most recent results, these graphite nodules show a mechanical properties gradient inside the graphite nodules, with the graphite elements – matrix debonding as only one of the possible damaging micromechanisms. In this work, two different ferritic DCIs were investigated (a ferritic matrix obtained from as-cast condition and a ferritized matrix) focusing on the damaging micromechanisms in graphite nodules due to tensile stress. Specimens lateral surfaces were observed using a Scanning Electron Microscope (SEM) during the tests following a step by step procedure.Fil: D' Agostino, Laura. Università di Cassino e del Lazio Meridionale; ItaliaFil: Di Cocco, Vittorio. Università di Cassino e del Lazio Meridionale; ItaliaFil: Fernandino, Diego Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Lacoviello, Francesco. Università di Cassino e del Lazio Meridionale; Itali

    Ultrafine particle apportionment and exposure assessment in respect of linear and point sources

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    Abstract The effects of particulate matter on the environment and public health were widely studied in recent years but agreement amongst these studies on the relative importance of the particle size and its origin with respect to health effects is still lacking. Nevertheless, air quality standards are moving towards greater focus on the smaller particles. In industrialized areas, anthropogenic activities are a major contributor to the particle concentrations. Then, it is important to characterize the emission sources as well as the evolution of particle size distribution in the proximity of these emission points. In this study, the authors evaluated the particle concentration and size distribution at a downwind receptor site of a linear (a major highway) and point (waste incinerator plant) source in an area characterized by high anthropic environmental impact. The particle emissions of the incinerator under examination were characterized by using a Scanning Mobility Particle Sizer ® (SMPS), an Aerodynamic Particle Sizer ® (APS) Spectrometer, a Rotating Disk Thermodiluter and a Thermal Conditioner (Matter Engineering AG). As regards the linear source, concentrations were determined at increasing distances from the most important Italian road, the A1 highway. Particle number, surface and mass exponentially decreases away from the freeway, whereas particle number concentration measured at 400 m downwind from the freeway is indistinguishable from upwind background concentration. Annual mean values of 8.6×10 ± 3.7×10 particle cm -3 and 31.1 ± 9.0 μg m -3 were found for particle number and PM 10 concentration, typical of a rural site. The particle apportionment and exposure assessment in respect of linear and point sources for ultrafine particles represent the major novelty of the present paper. The study here presented could be very important in developing appropriate management and control strategies for air quality in areas characterized by high anthropic pressure and to perform exposure assessment for populations involved


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    In the present research project, the authors developed wearable and portable solutions capable to improve safety in production lines by taking advantages of availability of exhaustive and reliable data in modern industrial plants. Indeed, the synergy between Industry 4.0 and cutting edge devices, such as smartphones and headsets for Mixed Reality demonstrated to be potentially used to assist personnel on the shop floor, especially during critical and most dangerous operations. In this paper it is presented an ongoing project devoted to develop such support systems and to evaluate their efficiency in multiple industrial environments

    Genome-Scale Mining of Acetogens of the Genus Clostridium Unveils Distinctive Traits in [FeFe]- and [NiFe]-Hydrogenase Content and Maturation

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    Mastering hydrogen metabolism can support a sustainable carbon-neutral economy. Of the many microorganisms metabolizing hydrogen, acetogens of the genus Clostridium are appealing, with some of them already in usage as industrial workhorses.Knowledge of the organizational and functional properties of hydrogen metabolism is pivotal to the construction of a framework supportive of a hydrogen-fueled low-carbon economy. Hydrogen metabolism relies on the mechanism of action of hydrogenases. In this study, we investigated the genomes of several industrially relevant acetogens of the genus Clostridium (C. autoethanogenum, C. ljungdahlii, C. carboxidivorans, C. drakei, C. scatologenes, C. coskatii, C. ragsdalei, C. sp. AWRP) to systematically identify their intriguingly diversified hydrogenases' repertoire. An entirely computational annotation pipeline unveiled common and strain-specific traits in the functional content of [NiFe]- and [FeFe]-hydrogenases. Hydrogenases were identified and categorized into functionally distinct classes by the combination of sequence homology, with respect to a database of curated nonredundant hydrogenases, with the analysis of sequence patterns characteristic of the mode of action of [FeFe]- and [NiFe]-hydrogenases. The inspection of the genes in the neighborhood of the catalytic subunits unveiled a wide agreement between their genomic arrangement and the gene organization templates previously developed for the predicted hydrogenase classes. Subunits' characterization of the identified hydrogenases allowed us to glean some insights on the redox cofactor-binding determinants in the diaphorase subunits of the electron-bifurcating [FeFe]-hydrogenases. Finally, the reliability of the inferred hydrogenases was corroborated by the punctual analysis of the maturation proteins necessary for the biosynthesis of [NiFe]- and [FeFe]-hydrogenases. IMPORTANCE Mastering hydrogen metabolism can support a sustainable carbon-neutral economy. Of the many microorganisms metabolizing hydrogen, acetogens of the genus Clostridium are appealing, with some of them already in usage as industrial workhorses. Having provided detailed information on the hydrogenase content of an unprecedented number of clostridial acetogens at the gene level, our study represents a valuable knowledge base to deepen our understanding of hydrogenases' functional specificity and/or redundancy and to develop a large array of biotechnological processes. We also believe our study could serve as a basis for future strain-engineering approaches, acting at the hydrogenases' level or at the level of their maturation proteins. On the other side, the wealth of functional elements discussed in relation to the identified hydrogenases is worthy of further investigation by biochemical and structural studies to ultimately lead to the usage of these enzymes as valuable catalysts

    Circular RNAs in embryogenesis and cell differentiation with a focus on cancer development

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    In the recent years thousands of non-coding RNAs have been identified, also thanks to highthroughput sequencing technologies. Among them, circular RNAs (circRNAs) are a well-represented class characterized by the high sequence conservation and cell type specific expression in eukaryotes. They are covalently closed loops formed through back-splicing. Recently, circRNAs were shown to regulate a variety of cellular processes functioning as miRNA sponges, RBP binding molecules, transcriptional regulators, scaffold for protein translation, as well as immune regulators. A growing number of studies are showing that deregulated expression of circRNAs plays important and decisive actions during the development of several human diseases, including cancer. The research on their biogenesis and on the various molecular mechanisms in which they are involved is going very fast, however, there are still few studies that address their involvement in embryogenesis and eukaryotic development. This review has the intent to describe the most recent progress in the study of the biogenesis and molecular activities of circRNAs providing insightful information in the field of embryogenesis and cell differentiation. In addition, we describe the latest research on circRNAs as novel promising biomarkers in diverse types of tumors

    Disasters and emergency management in chemical and industrial plants: Drones simulation for education and training

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    The use of simulation for training is proven to be extremely effective both in term of costs and in term of its flexibility for different uses and applications, such as building situation awareness and creating scenarios for training scopes. The aim of the project proposed is to demonstrate the powerful rule of simulation in UAV pilots\u2019 cooperative training; the project presented makes use of a 3D simulation environment in order to build a realistic condition of an emergency situation in a chemical plant for the first responders. The model proposed makes use of HLA (High Level Architecture) standards in order to be potentially federated with other existing simulators. In the solution proposed, the pilot of the drone must accomplish the mission in a given time piloting a UAV; the scenario is based inside a chemical plant where a disaster is newly occurred. Then ability of the pilot is measured by the system and several constraints are reproduced to provide a realistic training scenario (such as small spaces and barriers to overcome, battery durations, risks of damages due to high temperatures zones, etc.); the system records and tracks all the actions of the pilot and gives a feedback to the user at the end of the simulation time

    Comparison between early-onset and late-onset alzheimer's disease patients with amnestic presentation: CSF and 18F-FDG PET study

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    BACKGROUND/AIMS To investigate the differences in brain glucose consumption between patients with early onset of Alzheimer's disease (EOAD, aged ≤65 years) and patients with late onset of Alzheimer's disease (LOAD, aged >65 years). METHODS Differences in brain glucose consumption between the groups have been evaluated by means of Statistical Parametric Mapping version 8, with the use of age, sex, Mini-Mental State Examination and cerebrospinal fluid values of AΒ1-42, phosphorylated Tau and total Tau as covariates in the comparison between EOAD and LOAD. RESULTS As compared to LOAD, EOAD patients showed a significant decrease in glucose consumption in a wide portion of the left parietal lobe (BA7, BA31 and BA40). No significant differences were obtained when subtracting the EOAD from the LOAD group. CONCLUSIONS The results of our study show that patients with EOAD show a different metabolic pattern as compared to those with LOAD that mainly involves the left parietal lobe
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