543 research outputs found

    Modelling of autogenous healing for regular concrete via a discrete model

    Get PDF
    In this paper a numerical model for autogenous healing of normal strength concrete is presented in detail, along with preliminary results of its validation, which is planned to be achieved by comparing the results of numerical analyses with those of a dedicated experimental campaign. Recently the SMM (Solidification-Microprestress-Microplane model M4) model for concrete, which makes use of a modified microplane model M4 and the solidification-microprestress theory, has been extended to incorporate the autogenous healing effects. The moisture and heat fields, as well as the hydration degree, are obtained from the solution of a hygro-thermo-chemical problem, which is coupled with the SMM model. The updated model can also simulate the effects of cracking on the permeability and the restoring effect of the self-healing on the mechanical constitutive laws, i.e. the microplane model. In this work, the same approach is introduced into a discrete model, namely the Lattice Discrete Particle Model (LDPM). A numerical example is presented to validate the proposed computational model employing experimental data from a recent test series undertaken at Politecnico di Milano

    The influence of lexical selection disruptions on articulation

    No full text
    Interactive models of language production predict that it should be possible to observe long-distance interactions; effects that arise at one level of processing influence multiple subsequent stages of representation and processing. We examine the hypothesis that disruptions arising in nonform-based levels of planning—specifically, lexical selection—should modulate articulatory processing. A novel automatic phonetic analysis method was used to examine productions in a paradigm yielding both general disruptions to formulation processes and, more specifically, overt errors during lexical selection. This analysis method allowed us to examine articulatory disruptions at multiple levels of analysis, from whole words to individual segments. Baseline performance by young adults was contrasted with young speakers’ performance under time pressure (which previous work has argued increases interaction between planning and articulation) and performance by older adults (who may have difficulties inhibiting nontarget representations, leading to heightened interactive effects). The results revealed the presence of interactive effects. Our new analysis techniques revealed these effects were strongest in initial portions of responses, suggesting that speech is initiated as soon as the first segment has been planned. Interactive effects did not increase under response pressure, suggesting interaction between planning and articulation is relatively fixed. Unexpectedly, lexical selection disruptions appeared to yield some degree of facilitation in articulatory processing (possibly reflecting semantic facilitation of target retrieval) and older adults showed weaker, not stronger interactive effects (possibly reflecting weakened connections between lexical and form-level representations)

    A comparative study on trichoderma harzianum and a combination of candida/bacillus as tools for the bioremediation of table olive processing water

    Get PDF
    A comparative study was performed on Trichoderma harzianum and a combination of Candida boidinii/Bacillus pumilus to reduce the polluting effect of TOPW (Table Olive Processing Water) from the Spanish style. A 2k fractional design was used to study the effect of pH (6–11 for the fungus and 6–9 for Candida/Bacillus), temperature (10–35◦C) and duration (7–14 days for Candida/Bacillus and 14–21 days for T. harzianum), and the effect on phenol reduction, COD and color was evaluated. The experiments were also performed on diluted TOPW (dilution ratio 1:1). Generally, Trichoderma removed higher amounts of phenols and reduced COD more than the combination Candida/Bacillus, thus confirming the higher efficiency of filamentous fungi reported in the literature. The dilution of TOPW had an effect only on COD reduction; however, the effect was mild, at least for T. harzianum (4%), while yield increase was 9% for Bacillus/Candida. pH acted in a different way on phenol removal and COD reduction; an increase of pH caused a reduction of efficiency for COD, while the effect was positive for phenols

    TRPV4: Molecular Conductor of a Diverse Orchestra

    Get PDF
    Transient receptor potential vanilloid type 4 (TRPV4) is a calcium-permeable nonselective cation channel, originally described in 2000 by research teams led by Schultz ( Nat Cell Biol 2: 695 –702, 2000) and Liedtke ( Cell 103: 525–535, 2000). TRPV4 is now recognized as being a polymodal ionotropic receptor that is activated by a disparate array of stimuli, ranging from hypotonicity to heat and acidic pH. Importantly, this ion channel is constitutively expressed and capable of spontaneous activity in the absence of agonist stimulation, which suggests that it serves important physiological functions, as does its widespread dissemination throughout the body and its capacity to interact with other proteins. Not surprisingly, therefore, it has emerged more recently that TRPV4 fulfills a great number of important physiological roles and that various disease states are attributable to the absence, or abnormal functioning, of this ion channel. Here, we review the known characteristics of this ion channel's structure, localization and function, including its activators, and examine its functional importance in health and disease.</jats:p

    A brief review about anxiety and aggressive behavior in pediatric age

    Get PDF
    Anxiety can be considered a normal experience of the human being and as such also of the child. It manifests itself in different ways according to the level of development: in the smaller the child, the more anxiety is expressed with manifestations that involve the whole organism, becoming evident either with motor excitement or with physical discomfort. As the psychic apparatus is structured, anxiety is experienced as an inner phenomenon and is experienced as an unpleasant state. Fortunately, we are all a bit anxious, even if there are some people who are more, others less

    Prospectus, January 24, 1990

    Get PDF
    https://spark.parkland.edu/prospectus_1990/1001/thumbnail.jp

    The social brain and emotional contagion: Covid-19 effects

    Get PDF
    Background and objectives: Coronavirus disease 2019 (COVID-19) is a highly contagious infectious disease, responsible for a global pandemic that began in January 2020. Human/COVID-19 interactions cause different outcomes ranging from minor health consequences to death. Since social interaction is the default mode by which individuals communicate with their surroundings, different modes of contagion can play a role in determining the long-term consequences for mental health and emotional well-being. We examined some basic aspects of human social interaction, emphasizing some particular features of the emotional contagion. Moreover, we analyzed the main report that described brain damage related to the COVID-19 infection. Indeed, the goal of this review is to suggest a possible explanation for the relationships among emotionally impaired people, brain damage, and COVID-19 infection. Results: COVID-19 can cause several significant neurological disorders and the pandemic has been linked to a rise in people reporting mental health problems, such as depression and anxiety. Neurocognitive symptoms associated with COVID-19 include delirium, both acute and chronic attention and memory impairment related to hippocampal and cortical damage, as well as learning deficits in both adults and children. Conclusions: Although our knowledge on the biology and long-term clinical outcomes of the COVID-19 infection is largely limited, approaching the pandemic based on lessons learnt from previous outbreaks of infectious diseases and the biology of other coronaviruses will provide a suitable pathway for developing public mental health strategies, which could be positively translated into therapeutic approaches, attempting to improve stress coping responses, thus contributing to alleviate the burden driven by the pandemic

    Effects of a Plastic-Free Lifestyle on Urinary Bisphenol A Levels in School-Aged Children of Southern Italy: A Pilot Study

    Get PDF
    Bisphenol A (BPA) is an endocrine disruptor (ED) frequently used in food packaging. BPA is used as a monomer in the manufacture of some food packaging. This study aimed to evaluate the urinary BPA concentration in an Italian pediatric cohort, testing the levels of this ED over a period of 6 months, evaluating the effects of a diet regimen with a reduction of Plastic Food Packaging (PFP). One hundred thirty Italian children were enrolled and divided into two groups “School Canteen” and “No School Canteen.” The first group consumed one meal at school using a plastic-free service for 5 days/weeks, while the other group did not modify their normal meal-time habits. The BPA levels were tested in urine samples at three time points: T0, is the time before the application of the plastic-free regimen diet; T3, 3 months later; and T6, 6 months later. A reduction of urine BPA levels was detected in the “School Canteen” group. In particular, the reduction was significant analyzing both the intra (among the three testing times) group and inter (between “School Canteen” and “No School Canteen”) group variability. Our results show the effects of a diet regimen with a reduction of PFP, demonstrating a connection between urinary BPA levels and food packaging

    Crack healing under sustained load in concrete: An experimental/numerical study

    Get PDF
    The need of sustainable resilient structures and infrastructures push towards the use of cementitious materials able to heal micro-cracks and defects. For real structural application under service loading the time-dependent behavior is of the utmost importance, especially in presence of cracks which can lead to a nonlinear creep behavior that might cause the structural failure. Now the new challenge is to study and quantify the effect of crack-healing on the nonlinear creep behavior. This study aims at the following goals: 1) to characterize with experimental investigations the effect of the healing in tests in which the specimens, along the exposure time and under controlled environmental conditions, are under sustained load, the expected service load, determined as a fraction of the pre-cracking load; 2) develop a comprehensive numerical framework for the interpretation and simulation of the experimentally observed results. To this purpose an experimental investigation is currently ongoing at Politecnico di Milano with reference to an Ultra High-Performance Concrete developed in the framework of the H2020 ReSHEALience project for exposure to extremely aggressive environments. The numerical framework is based on the recent developments of the multiphysics lattice particle model
    • …
    corecore