Classification of ductile cast iron specimens: A machine learning approach

In this paper an automatic procedure based on a machine learning approach is proposed to classify ductile cast iron specimens according to the American Society for Testing and Materials guidelines. The mechanical properties of a specimen are strongly influenced by the peculiar morphology of their graphite elements and useful characteristics, the features, are extracted from the specimens’ images; these characteristics examine the shape, the distribution and the size of the graphite particle in the specimen, the nodularity and the nodule count. The principal components analysis are used to provide a more efficient representation of these data. Support vector machines are trained to obtain a classification of the data by yielding sequential binary classification steps. Numerical analysis is performed on a significant number of images providing robust results, also in presence of dust, scratches and measurement noise

Cross-Comparison of MODIS and CloudSat Data as a Tool to Validate Local Cloud Cover Masks

This paper presents a cross-comparison of the data acquired by the MODIS and CloudSat sensors in order to understand the limit of the developed cloud-mask algorithm and to provide a quantitative validation assessment of cloud masks by using exclusively remotely sensed data. The analysis has been carried out by comparing both the intermediate levels of the cloud mask such as the brightness temperatures and the reflectance values for different channels, and the cloud mask itself with the cloud profiles as measured by the CloudSat sensor. The comparison between MODIS cloud tests and the CloudSat profiles indicates an agreement with hit rates (H) and Hanssen-Kuiper Skill Score (KSS) varying between 0.7 and 1.0 and 0.4 and 1.0, respectively. In this case, the low values of H and KSS are found due to the limitation of CloudSat to detect low clouds. The comparison between the cloud mask and the CloudSat profile determines H and KSS values between 0.6 and 1, except for one case. The CloudSat profile has also been compared with the Standard MODIS cloud mask in order to understand the improvement obtained in the use of local adapted thresholds. A comparison of MODIS and CALIPSO data is also presented

Improved Zn-based coatings for ipersandelin steel products

The protection of iron-based alloy products against corrosion is fundamental to preserve their mechanical properties in aggressive environments. Hot-dip galvanizing process represents one of the most used techniques to make protective coatings for such products. In order to improve both mechanical and chemical properties of coating, metallic elements may be added to the traditional zinc bath. In the present paper, two types of improved zinc-based coating are proposed: (i) A coating obtained employing a tin addition (3% in weight); (ii) A coating obtained employing aluminium (5% in weight), tin (1% in weight) and copper (0.5% in weight) additions. Firstly, the performance of such two types of coatings is experimentally investigated through bending tests on ipersandelin steel plate specimens, treated through different bath dipping times. The intermetallic phase thicknesses of coatings are measured for each dipping time, in order to evaluate the kinetic formation. Then, a Finite Element (FE) model is proposed in order to simulate the bending behaviour of the above specimens, both employing the measured phase thickness and implementing the loading and boundary conditions of the experimental tests. A numerical non-linear static analysis is performed. A quite satisfactory agreement between experimental and numerical results is observed, especially under plastic behaviour regime

Anticipatory Feelings in Intertemporal Choice on Consumption: A Dynamic Experiment

Following the evaluation of anticipatory feelings in Scitovsky\u2019s Joyless Economy, we explored a specific interpretation of reversals in intertemporal choice. Anticipatory feelings can be explained as the feeling experienced by the agent while awaiting an upcoming event. We adopted a dynamic experiment where individuals made decisions of consumption at multiple points of time: three experimental sessions in three different dates at two-week intervals. We elicited the initial plans of the same sample in three different sessions over a one-month period and tracked how they implemented their plans as the anticipated event drew closer. The paper innovates with respect to the literature on intertemporal decision making in that the motivation for a varying discount rate, caused by anticipation or procrastination, has been elicited with both monetary and non-monetary (consumption) incentives and within a dynamic setting. We found that anticipatory feeling is a significant possible explanation behind choice reversal. The results remained significant after controlling the other explanatory factors such as risk aversion, uncertainty and time inconsistency

Graphite nodules features identifications and damaging micromechanims in ductile irons

Ductile irons mechanical properties are strongly influenced by the metal matrix microstructure and on the graphite elements morphology. Depending on the chemical composition, the manufacturing process and the heat treatments, these graphite elements can be characterized by different shape, size and distribution. These geometrical features are usually evaluated by the experts visual inspection, and some commercial softwares are also available to assist this activity. In this work, an automatic procedure based on an image segmentation technique is applied: this procedure is validated not only considering spheroidal graphite elements, but also considering other morphologies (e.g. lamellae)

Mechanical behaviour and phase transition mechanisms of a shape memory alloy by means of a novel analytical model

The aim of the present paper is to examine both the fatigue behaviour and the phase transition mechanisms of an equiatomic pseudo-elastic NiTi Shape Memory Alloy through cyclic tests (up to 100 loading cycles). More precisely, miniaturised dog-bone specimens are tested by using a customised testing machine and the contents of both austenite and martensite phase are experimentally measured by means of X-Ray diffraction (XRD) analyses. On the basis of such experimental results in terms of martensite content, an analytical model is here formulated to correlate the stress-strain relationship to the phase transition mechanisms. Finally, a validation of the present model by means of experimental data pertaining the stress-strain relationship is performed

Advanced numerical treatment of an accurate SPH method

The summation of Gaussian kernel functions is an expensive operation frequently encountered in scientific simulation algorithms and several methods have been already proposed to reduce its computational cost. In this work, the Improved Fast Gauss Transform (IFGT) [1] is properly applied to the Smoothed Particle Hydrodynamics (SPH) method [2] in order to speed up its efficiency. A modified version of the SPH method is considered in order to overcome the loss of accuracy of the standard formulation [3]. A suitable use of the IFGT allows us to reduce the computational effort while tuning the desired accuracy into the SPH framework. This technique, coupled with an algorithmic design for exploiting the performance of Graphics Processing Units (GPUs), makes the procedure promising as shown by preliminary numerical simulations

Clinical Evaluation and Orodental Status in a Group of Elderly Institutionalised Patients

10% of elderly patients are functionally dependents and they therefore need permanent assistance. Orodental alterations may evolve into a pathological state in elderly people, which is increasing in the recent decades. The current study analysed institutionalized patients in the district of Bari (Southern Italy), who have been so far monitored. We assessed 125 elderly institutionalized patients. The assessment has been carried out by an assessment questionnaire aiming at evaluating the patient’s psychophysical health status, objective intraoral test and prosthetic rehabilitations. About 90% of enrolled patients reported a good general health status. The main dental problems are due to the complete lack of specific prevention and treatment programs, together with handicap, presence of systemic diseases and medicines taken. The level of oral hygiene is poor and the conditions of the residual dental elements are precarious because of root caries and periodontal problems. Prostheses are usually old (on average 15) and appear scarcely retentive and unstable. We believe in the need for specific interventions aiming at the various issues emerging from the present study, so as to achieve a smaller prevalence of dental loss, periodontal disease and caries. These relatively simple interventions are now lacking because of the non-demand of treatment from patients and for economical reasons

Rationale for an association between PD1 checkpoint inhibition and therapeutic vaccination against HIV

The pathogenesis of HIV immunodeficiency is mainly dependent on the cytopatic effects exerted by the virus against infected CD4+ T cells. However, CD4+ T cell loss cannot be the only pathogenic factor since severe opportunistic infections may develop in HIV infected patients with normal CD4+ T cell counts and since the recent START study indicated that absolute CD4+ T cell counts are not predictive for AIDS and non-AIDS events. Recently our group demonstrated that CD8+CD28-CD127lowCD39+ regulatory T lymphocytes, previously found highly concentrated within tumor microenvironment, circulate with elevated frequency in the peripheral blood of HIV infected patients. Here, we show that these cells, that at least in part are HIV specific, express the PD1 immune checkpoint. Based on these evidences and considerations, in this Perspective article we speculate on the opportunity to treat HIV infected patients with anti-PD1 immune checkpoint inhibitors as a way to counteract the T regulatory cell compartment and to unleash virus-specific immune responses. In order to potentiate the immune responses against HIV we also propose the potential utility to associate immune checkpoint inhibition with HIV-specific therapeutic vaccination, reminiscent of what currently applied in oncologic protocols. We suggest that such an innovative strategy could permit drug-sparing regimens and, perhaps, lead to eradication of the infection in some patients

Assessment of psychopatologic traits in a group of patients with adult chronic periodontitis: Study on 108 cases and analysis of compliance during and after periodontal treatment

Objectives: Although there is nowadays wide agreement on bacteria being the main etiologic agents of periodontal disease, their sole presence cannot damage periodontal tissues in all subjects. This suggests that an individual response and an adaptation to a certain quantity of bacterial biofilm can occur without the disease progressing and vice versa. Depression, stress and anxiety have not been confirmed yet as risk conditions but, in some observational studies, they have been identified as potential risk factors of periodontal disease. The current study aims at investigating the role which these psychological disorder have in the onset and progression of advanced stage periodontitis. Materials and methods: The case selection was carried out by means of clinical and radiological periodontal assessment involving a total of 108 subjects, both male and female, aged between 24 and 67. Patients were then divided in two groups of 54 patients each: the first group included patients with severe periodontal disease, the second group was formed by periodontally healthy subjects. Clinical assessment was performed by a sole examiner who selected and divided periodontopathic patients from non-periodontopathic ones. From the current study were excluded: patients with systemic pathologies; smokers; patients taking antidepressant drugs; pregnant women. Results: For what concerns depression, in the group of periodontopathic patients it was found that the 62.5% of them were depressed, against the 38.86% in the group of periodontally healthy subjects. For the other two psychological conditions taken into consideration, anxiety and stress, it emerged a different percentage of subjects with anxiety in the periodontal group (31.48%) against healthy controls (20.37%). Conclusions: For each of the psychological variables considered (depression, anxiety, stress), a significant correlation could be observed with periodontal disease, it can be therefore be suggested that the importance these disturbs have in the onset and progress of the dental disease which supports the existing available data in literature. The innovative aspect of this research was the focus on the assessment of compliance, monitoring the ability of periodontal patients to follow oral hygiene instructions aiming at the improving and keeping their own periodontal condition, even though this takes more time than the control group