In recent years, the scientific community of nuclear fusion raised the issue of thermophysical properties of lead lithium alloys. These alloys are foreseen to be used in several Breeding Blanket ...concepts in an almost eutectic composition, but only few data on the properties are available in literature and large differences on the same property exist between different authors. Moreover, apparently each organization used different available properties correlations, making practically pointless every comparison of results with the other organizations involved in the design of Breeding Blankets. The aim of this paper is to identify the properties to be used in the design of the Breeding Blankets, performing a literature review of the available data and suggesting a correlation for each of the main properties. These correlations were chosen based on the accurateness of the paper and on the similarities between different authors, where it was possible (e.g., density). The table with the correlations should represent a starting point for a discussion to reach a general consensus on the property database, which should be mandatory in order to allow a comparison of the results from different organizations. Very likely new experiments will be necessary to definitely measure at least the properties with the biggest scattering of the data (e.g., specific heat), encouraging a consensus and reducing the errors in the design activities.
The aim of this study was to systematically review the literature to assess if low-temperature degradation (LTD) simulation in autoclave promotes deleterious impact on the mechanical properties and ...superficial characteristics of Y-TZP ceramics compared to the non-aged protocol. The MEDLINE via PubMed electronic database was searched with included peer-reviewed publications in English language and with no publication year limit. From 413 potentially eligible studies, 49 were selected for full-text analysis, 19 were included in the systematic review with 12 considered in the meta-analysis. Two reviewers independently selected the studies, extracted the data, and assessed the risk of bias. Statistical analysis was performed using RevMan 5.1, with random effects model, at a significance level of p<0.05. Descriptive analysis of monoclinic phase content data showed that aging in autoclave promotes an increase in m-phase content (ranging from 0% up to 13.4% before and 2.13% up to 81.4% after aging) with intensity associated to the material susceptibility and to the aging parameters (time, pressure and temperature). Risk of bias analysis showed that only 1 study presented high risk, while the majority showed medium risk. Five meta-analyzes (factor: aging×control) were performed considering global and subgroups analyzes (pressure, time, temperature and m-phase % content) for flexural strength data. In the global analysis a significant difference (p<0.05) was observed between conditions, favoring non-aging group. Subgroup analysis revealed statistical difference (p<0.05) favoring non-aging, for aging time >20h. However, for shorter aging times (≤20h), there was no difference between groups. Pressure subgroup analysis presented a statistical difference (p<0.05) only when a pressure ≥2bar was employed, favoring non-aging group. Temperature subgroup analysis showed a statistical difference (p<0.05) only when temperature=134°C was used, favoring the non-aging group. M-phase % content analysis presented statistical difference (p<0.05) when more than 50% of m-phase content was observed, favoring non-aging group. High heterogeneity was found in some comparisons. Aging in autoclave promoted low-temperature degradation, impacting deleteriously on mechanical properties of Y-TZP ceramics. However, the effect of LTD depends on some methodological parameters indicating that aging time higher than 20h; pressure ≥2bar and temperature of 134°C are ideal parameters to promote LTD effects, and that those effect are only observed when more than 50% m-phase content is observed.
The paper aims to explore the drivers of immigrants’ participation to cultural and leisure activities in host countries. First, we discuss how the main analytical approaches on cultural participation ...can be extended to incorporate factors specific to migrants’ characteristics and behaviour, namely cultural traits or proximity to the native population’s culture and the level of integration in the host society. Secondly, we estimate zero-inflated ordered probit models to investigate migrants’ propensity and frequency to engage in cultural and leisure activities using data of a special survey on Income and Living conditions (2011–2012) on foreign households in Italy. Italy represents an interesting case because it is a recent immigration country, making the analysis particularly suitable for studying the behaviour of first-generation immigrants. Our findings suggest that, after controlling for standard individual predictors, cultural participation is significantly and primary driven by the process of acculturation which take place during the staying in the host country. Conversely, we find only a partial or weak evidence of the effect of both personal cultural capital and of the heterogeneity in migrants’ cultural traits on variation in participation rates.
Systemic sclerosis (SSc) is an autoimmune disease which may lead to malnutrition. Previous studies have defined it with different criteria. No thorough evaluations of sarcopenia in SSc are available. ...The aim of the present study was to assess the prevalence and the potential association of malnutrition and sarcopenia in a large cohort of SSc cases. A total of 141 SSc consecutive outpatients were enrolled. Body composition was analyzed by densitometry. Malnutrition was defined according to recently published ESPEN criteria, whereas sarcopenia was diagnosed in patients with reduced skeletal muscle index. Malnutrition was diagnosed in 9.2% of patients (95% CI, 4.4–14.0%). Malnourished patients had worse gastrointestinal symptoms according to UCLA SCTC GIT 2.0 questionnaire (
p
= 0.007), lower physical activity (
p
= 0.028), longer disease duration (
p
= 0.019), worse predicted DLCO/VA and FVC (
p
= 0.009, respectively), worse disease severity according to Medsger severity score (
p
< 0.001), lower hemoglobin (
p
= 0.023), and fat-free mass (
p
< 0.001) and were more often sarcopenic (
p
< 0.001). In multivariate analysis, only FVC (
p
= 0.006) and disease severity (
p
= 0.003), in particular for the lungs (
p
= 0.013), were confirmed to be worse in malnourished patients. Sarcopenia was diagnosed in 29\140 patients (20.7%; 95% CI, 14.0–27.4%); 11\29 were also malnourished. In multivariate analysis, sarcopenic patients had longer disease duration (
p
= 0.049), worse DLCO/VA (
p
= 0.002), and lung (
p
= 0.006) and skin (
p
= 0.014) involvement. In SSc, malnutrition defined with ESPEN criteria was found to be lower than previously reported. Sarcopenia was found to be somewhat common. Lung involvement was significantly associated with nutritional status and may not be explained only by muscle weakness.
The chemical composition and biological properties of Portuguese wild mushrooms (Cantharellus cibarius, Hypholoma fasciculare, Lepista nuda, Lycoperdon molle, Lycoperdon perlatum, Ramaria botrytis, ...Tricholoma acerbum) were evaluated in order to assess these products as sources of nutrients and nutraceuticals. The analyzed mushrooms contain very useful phytochemicals such as phenolics, tocopherols, ascorbic acid, and carotenoids. All of the species proved to have antioxidant activity (measured by four different methods), being more significant for R. botrytis (EC50 values < 1 mg/mL). Lycoperdon species were resistant to all of the tested microorganisms, and the other samples revealed antimicrobial activity selectively against Gram-positive bacteria, with very low minimal inhibitory concentration, in some cases, even lower than the standard. The combination of bioactive compounds and rich nutritional composition (high contents in protein and carbohydrates, low content in fat with the precious contribution of unsaturated fatty acids and the absence of trans fatty acids) in the mushroom makes it a very special food.
The cylindrical drift chamber is the most innovative part of the MEG II detector, the upgraded version of the MEG experiment. The MEG II chamber differs from the MEG one because it is a single volume ...cylindrical structure, instead of a segmented one, chosen to improve its resolutions and efficiency in detecting low energy positrons from muon decays at rest. In this paper, we show the characteristics and performances of this fundamental part of the MEG II apparatus and we discuss the impact of its higher resolution and efficiency on the sensitivity of the MEG II experiment. Because of its innovative structure and high quality resolution and efficiency the MEG II cylindrical drift chamber will be a cornerstone in the development of an ideal tracking detector for future positron-electron collider machines.
•Results of RELAP5-3D simulations of an experimental campaign in a mock-up of the HCLL TBS LiPb loop.•RELAP5-3D is able to accurately reproduce the pressure wave propagation in the facility.•Two main ...general differences between numerical and experimental results have been highlighted.•Average discrepancy of about 3.5 bar between experimental data and numerical results on 5 tests.•The code accurately predicts the first pressure peak, the most relevant input for the designers.
In this work the capabilities of RELAP5-3D are tested against the experimental data gathered in the first experimental campaign on THALLIUM (Test HAmmer in Lead LIthiUM). THALLIUM, a LiPb facility, was built in 2015 at ENEA R.C. Brasimone with the aim to study the In-box LOCA by reproducing the LiPb loop of the HCLL TBS and the pipe forest at 1:1 scale. HCLL TBS (Helium Cooled Lithium-Lead Test Blanket System) was one of the Breeding Blanket concepts selected for ITER. The ITER classification system identified the In-box LOCA as a critical accidental transient for this type of TBS. For this reason, codes able to reproduce the consequences of this transient are needed to support the design of the LiPb loop. The simulations with RELAP5-3D used LBE (Lead-Bismuth Eutectic) as system fluid, as the thermophysical properties of LiPb are tabulated only up to a maximum value of 40 bar. The results of the simulations suggest that RELAP5-3D is able to reproduce the pressure wave propagation in the facility, with an average discrepancy of about 3.5 bar (i.e. an average percentage discrepancy of about 9.7 %), but also highlight two general discrepancies between computations and experiments.
The scope of the EUFOfusion Work Package Breeding Blanket is to develop a blanket concept for the EU DEMO reactor; this includes the blanket segments inside the Vacuum Vessel and the related Tritium ...Extraction/Removal Systems. In the Pre-Concept Design (PCD) Phase, two concepts have been selected as candidates; a solid and a liquid breeder blanket cooled with helium and water, respectively. The design of these two blanket systems has been adapted to the DEMO plant design developed in the PCD Phase and performances assessed. A large R&D programme has been implemented with the scope to evaluate different technologies for these blankets; including the development of breeders, tritium extraction and cooling technologies, and the manufacturing of the blanket system. A major milestone in the subsequent Concept Design Phase is the final selection of the blanket concept for DEMO.
The presence of the periodontal ligament (PDL) makes it possible to absorb and distribute loads produced during masticatory function and other tooth contacts into the alveolar process via the ...alveolar bone proper. However, several factors affect the integrity of periodontal structures causing the destruction of the connective matrix and cells, the loss of fibrous attachment, and the resorption of alveolar bone.
The purpose of this study was to evaluate the stress distribution by finite element analysis in a PDL in three-dimensional models of the upper central incisor under three different load conditions: 100 N occlusal loading at 45 degrees (model 1: masticatory load); 500 N at the incisal edge at 45 degrees (model 2: parafunctional habit); and 800 N at the buccal surface at 90 degrees (model 3: trauma case). The models were built from computed tomography scans.
The stress distribution was quite different among the models. The most significant values (harmful) of tensile and compressive stresses were observed in models 2 and 3, with similarly distinct patterns of stress distributions along the PDL. Tensile stresses were observed along the internal and external aspects of the PDL, mostly at the cervical and middle thirds.
The stress generation in these models may affect the integrity of periodontal structures. A better understanding of the biomechanical behavior of the PDL under physiologic and traumatic loading conditions might enhance the understanding of the biologic reaction of the PDL in health and disease.
Permeator Against Vacuum (PAV) is one of the technologies proposed for the Tritium Extraction and Removal System (TERS) of the Water-Cooled Lithium Lead Breeding Blanket (WCLL BB). The paper presents ...the activity aimed at the engineering design of a PAV mock-up with a niobium membrane, in order to later assemble and qualify it. Experience gained in the engineering design of the mock-up, the heating system, the instrumentation, and the vacuum line is illustrated. This experience will be useful for the preliminary design, the manufacturing and the operation of the PAV with niobium membrane for DEMO. Niobium was selected as membrane material of this mock-up because of its high permeability and for its lower cost compared to vanadium, the other candidate material for membranes. Besides, niobium has a lower tendency to oxidation than vanadium. Oxidation would reduce the hydrogen isotopes permeation flux. In this paper, the solution adopted to manufacture the PAV mock-up, a complex component with niobium and P22 parts, is illustrated. The Nb/P22 welding issues are also presented, in particular related to the compatibility of the welded joints with LiPb. In the chosen design, the LiPb flows with two passages in 16 (8 + 8) niobium “U” shaped pipes installed in a vacuum chamber and welded to a P22 plate. The U-pipes configuration was selected to minimize the welding area, the volume of the component and the membrane thickness while trying to preserve the highest possible extraction efficiency.
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