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The emergence of deliberate ignorance, i.e. what influences children's deliberate decisions not to seek information, is a phenomenon so far notably overlooked. This project addresses this gap by investigating various factors that systematically modulate such decisions in children and adults. Across five studies, we presented participants with short stories illustrating social situations where a misdeed occurs, and measured participants' preference for knowing the identity of the wrongdoer. Studies 1-3 (N = 550) shows that both children and adults systematically manifest a preference for ignorance when the information value is low, and when the potential wrongdoer is suspected to be a friend. Studies 4-5 (N = 333) further investigate the role of information probability in this phenomenon. This first contribution shows that children's preference for deliberate ignorance is modulated by information value and the relationship frame proposed, suggesting a rational approach to ignorance.

Introduction: Non-operative management (NOM) of uncomplicated acute appendicitis is a well-established alternative to upfront surgery. The administration of intravenous broad-spectrum antibiotics is usually performed in hospital, and only one study described outpatient NOM. The aim of this multicentre retrospective non-inferiority study was to evaluate both safety and non-inferiority of outpatient compared to inpatient NOM in uncomplicated acute appendicitis. Methods: The study included 668 consecutive patients with uncomplicated acute appendicitis. Patients were treated according to the surgeon's preference: 364 upfront appendectomy, 157 inpatient NOM (inNOM), and 147 outpatient NOM (outNOM). The primary endpoint was the 30-day appendectomy rate, with a non-inferiority limit of 5%. Secondary endpoints were negative appendectomy rate, 30-day unplanned emergency department (ED) visits, and length of stay. Results: 30-day appendectomies were 16 (10.9%) in the outNOM group and 23 (14.6%) in the inNOM group (p = 0.327). OutNOM was non-inferior to inNOM with a risk difference of-3.80% 97.5% CI (- 12.57; 4.97). No difference was found between inNOM and outNOM groups for the number of complicated appendicitis (3 vs. 5) and negative appendectomy (1 vs. 0). Twenty-six (17.7%) outNOM patients required an unplanned ED visit after a median of 1 (1-4) days. In the outNOM group, the mean cumulative in-hospital stay was 0.89 (1.94) days compared with 3.94 (2.17) days in the inNOM group (p < 0.001). Conclusions: Outpatient NOM was non-inferior to inpatient NOM with regard to the 30-day appendectomy rate, while a shorter hospital stay was found in the outNOM group. Further, studies are required to confirm these findings.

QC 20231031

Objectives: T1 mapping (T1-map) and cardiac magnetic resonance feature tracking (CMR-FT) techniques have been introduced for the early detection of interstitial myocardial fibrosis and deformation abnormalities. We sought to demonstrate that T1-map and CMR-FT may identify the presence of subclinical myocardial structural changes in patients with mitral valve prolapse (MVP). Methods: Consecutive MVP patients with moderate-to-severe mitral regurgitation and comparative matched healthy subjects were prospectively enrolled and underwent CMR-FT analysis to calculate 2D global and segmental circumferential (CS) and radial strain (RS) and T1-map to determine global and segmental native T1 (nT1) values. Results: Seventy-three MVP patients (mean age, 57 ± 13 years old; male, 76%; regurgitant volume, 57 ± 21 mL) and 42 matched control subjects (mean age, 56 ± 18 years; male, 74%) were included. MVP patients showed a lower global CS (− 16.3 ± 3.4% vs. − 17.8 ± 1.9%, p = 0.020) and longer global nT1 (1124.9 ± 97.7 ms vs. 1007.4 ± 26.1 ms, p < 0.001) as compared to controls. Moreover, MVP patients showed lower RS and CS in basal (21.6 ± 12.3% vs. 27.6 ± 8.9%, p = 0.008, and − 13.0 ± 6.7% vs. − 14.9 ± 4.1%, p = 0.013) and mid-inferolateral (20.6 ± 10.7% vs. 28.4 ± 8.7%, p < 0.001, and − 12.8 ± 6.3% vs. − 16.5 ± 4.0%, p < 0.001) walls as compared to other myocardial segments. Similarly, MVP patients showed longer nT1 values in basal (1080 ± 68 ms vs. 1043 ± 43 ms, p < 0.001) and mid-inferolateral (1080 ± 77 ms vs. 1034 ± 37 ms, p < 0.001) walls as compared to other myocardial segments. Of note, nT1 values were significantly correlated with CS (r, 0.36; p < 0.001) and RS (r, 0.37; p < 0.001) but not with regurgitant volume. Conclusions: T1-map and CMR-FT identify subclinical left ventricle tissue changes in patients with MVP. Further studies are required to correlate these subclinical tissue changes with the outcome. Key Points: • T1 mapping (T1-map) and cardia

Introduction: Postural stability can be maintained in balance by muscle tone [1]. Change in the mandibular position or posture, may have influence in the postural reflex, defined as an involuntary defense movement [2] to correct deviations and keep the body in balance. If the postural change is constant, the muscles will move the mandible to a more comfortable position, with consequent postural change2 and plantar support. The aim of the study was to compare the plantar support in centralized and in lateralization mandibular position in seven years’ children. Main text: This study was approved by research ethics committee (No. 4.346.542). A pilot study was carried out with seven-year-old children of both sexes. Photogrammetry was performed with spherical markers in the region of the right tragus and chin symphysis (Fig. 1) concomitantly with baropodometry following (Fig. 2, 3) the protocol established by Bittar et al. [4]. Analysis of mandibular displacement and plantar support were performed with centralized mandibular position (maximum intercuspation) and with lateral displacement to the right and left. Statistical analysis compared the differences in mandibular displacement to the right and left sides using Student’s t test. Differences in plantar support variables with centralized mandibular position and in right and left lateralization position were established by the Anova one way test and the Bonferroni pos test. Significant statistical difference was reached by 5 %. Results: Twelve seven-year-old children were included, 20.8 (3.25) Kg and 1.18 (0.06) meters. The sample present greater lateral displacement of the mandible to the lefts compared to right side. Mandibular lateralization was confirmed with statistical difference compared to mandibular position centralized. No difference in all plantar support variables was observed between the three positions: centralized and left and right lateralization. Conclusions: No differences were observed for plantar sup

Information extraction from narrative clinical notes is useful for patient care, as well as for secondary use of medical data, for research or clinical purposes. Many studies focused on information extraction from English clinical texts, but less dealt with clinical notes in languages other than English. This study tested the feasibility of using 'off the shelf' information extraction algorithms to identify medical concepts from Italian clinical notes. We used MetaMap to map medical concepts to the Unified Medical Language System (UMLS). The study addressed two questions: (Q1) to understand if it would be possible to properly map medical terms found in clinical notes and related to the semantic group of 'Disorders' to the Italian UMLS resources; (Q2) to investigate if it would be feasible to use MetaMap as it is to extract these medical concepts from Italian clinical notes. Results in EXP1 showed that the Italian UMLS Metathesaurus sources covered 91% of the medical terms of the 'Disorders' semantic group, as found in the studied dataset. Even if MetaMap was built to analyze texts written in English, it worked properly also with texts written in Italian. MetaMap identified correctly about half of the concepts in the Italian clinical notes. Using MetaMap's annotation on Italian clinical notes instead of a simple text search improved our results of about 15 percentage points. MetaMap showed recall, precision and F-measure of 0.53, 0.98 and 0.69, respectively. Most of the failures were due to the impossibility for MetaMap to generate Italian meaningful variants. MetaMap's performance in annotating automatically translated English clinical notes was in line with findings in the literature, with similar recall (0.75), F-measure (0.83) and even higher precision (0.95)., Comment: This paper has been published in the Journal of biomedical informatics, Volume 63, October 2016, Pages 22-32

An innovative solvent based on the quaternary system CO2-NH3-K2CO3-H2O is reported and characterized in terms of its thermodynamic properties and rate of CO2 absorption. Thermodynamic properties of the solvent such as vapor-liquid equilibrium, solid-liquid equilibrium, and the heat of desorption were modelled with the Extended UNIQUAC thermodynamic model. The kinetics of CO2 absorption in the solvent were studied experimentally with a wetted wall column set-up. The absorption rate was investigated with respect to temperature, ammonia concentration, potassium carbonate concentration, and CO2 loading, under the typical operating conditions of a capture plant. Globally, the solvent has a number of interesting properties for CO2 capture applications. Indeed, adding K2CO3 to the ammonia solvent reduced both the ammonia slip and the heat of desorption. Experimental analysis showed that the kinetics of absorption were mainly influenced by the reaction between free ammonia and CO2. Hence, the overall mass transfer coefficient decreased when increasing the K2CO3 content of the solvent.

This work compares the part load techno-economic performance of CO2 capture from a CCGT using a membrane configuration with selective CO2 recycle and using MEA solvent, under the assumption of flexible power plant dispatch. This is the first time that the techno-economic performance of CO2 capture technologies is compared assuming a flexible dispatch profile, and the assessment was done using a comprehensive, new, part load assessment approach. Analysing the part load performance of CCS technologies is relevant because of significant changes in our power systems, dramatically reducing the utilisation of thermal power plants. The technical performance of the configurations with and without CCS was simulated at steady state, at operating points between maximum continuous rating (100% gas turbine loading), and minimum stable load (35% gas turbine loading). The performance at these operating points was then aggregated into weighted averages to produce single performance indicators (specific CO2 intensity, specific primary energy per tonne of CO2 avoided (SPECCA), and levelised cost of electricity (LCOE)) over the dispatch profile of the power plant. The technical performance of the MEA configuration was favourable over the membrane configuration over the whole CCGT loading range. The MEA SPECCA increased from 3.02 GJ/t CO2 at 100% GT loading, to 3.65 GJ/t CO2 at 35% GT loading; the membrane SPECCA increased from 3.35 to 4.20 GJ/t CO2. The higher SPECCA of the membrane configuration is caused by the reduced gas turbine efficiency, due to the selective recycling of CO2 to the GT. When equal GT efficiency was assumed for combustion with normal air and with CO2 enriched air, the membranes' technical performance was comparable with that of MEA. The capital costs of the CCGT with membrane configuration were 35% higher than the CCGT with MEA configuration. That, and the 6-year replacement frequency of the membranes led the membrane LCOE to be 10 €/MWh higher than the MEA LC

The absorption reaction between aqueous NH3 and CO2 was studied using the Wetted Wall Column. A total of 27 different cases are investigated in the region defined by temperatures from 15 °C to 35 °C, NH3 concentrations from 5% to 15%, which are the typical solvent conditions in absorption columns, and lastly CO2 loadings from 0.2 to 0.6. The resulting overall mass transfer coefficient of absorption measured follows the trends described by the modelling of the reactor and the equations used to describe the rate of the absorption reactions. Moreover, the overall mass transfer coefficient of absorption is in agreement with data available in the literature, valid in smaller portions of the investigated region. From the data analysis, the kinetics of the absorption reactions in the liquid phase is characterized. The equation proposed to fit the data is a power law equation which reproduces the experimental results measured at different CO2 loadings. This represents a novelty because in literature the kinetic model of the reaction is usually fitted only to data for unloaded solutions (CO2 loading equal to zero). Hence, in this case there is an experimental evidence that the kinetic model holds true in every loading conditions. The kinetic model intercept the values found in literature in every range of concentration. Consequently, the model is valid in every conditions and the rate of the reaction between NH3 and CO2 in liquid phase is described with an Arrhenius constant with a pre-exponential factor of 1.41·108 [mol/(m3s)] and an activation energy of 60,680 [J/mol], a linear dependence on the CO2 concentration and a dependence on the NH3 with an exponent γ = 1.89. The proposed equation is found to be appropriate for implementation into process simulation software.

This work compares the part load techno-economic performance of CO2 capture from a combined cycle gas turbine (CCGT) using a membrane configuration with selective CO2 recycle and using monoethanolamine (MEA) solvent, under the assumption of flexible power plant dispatch. This is the first time that the techno-economic performance of CO2 capture technologies is compared assuming a flexible dispatch profile, and the assessment was done using a comprehensive, new, part load assessment approach. Analyzing the part load performance of CO2 capture and storage (CCS) technologies is relevant because of significant changes in our power systems, dramatically reducing the utilization of thermal power plants. The technical performance of the configurations with and without CCS was simulated at steady state, at operating points between maximum continuous rating (100% gas turbine loading) and minimum stable load (35% gas turbine loading). The performance at these operating points was then aggregated into weighted averages to produce single performance indicators (specific CO2 intensity, specific primary energy per tonne of CO2 avoided (SPECCA), and levelized cost of electricity (LCOE)) over the dispatch profile of the power plant. The technical performance of the MEA configuration was favorable over the membrane configuration over the whole CCGT loading range. The MEA SPECCA increased from 3.02 GJ/(t of CO2) at 100% GT loading to 3.65 GJ/(t of CO2) at 35% GT loading; the membrane SPECCA increased from 3.35 to 4.20 GJ/(t of CO2). The higher SPECCA of the membrane configuration is caused by the reduced gas turbine efficiency, due to the selective recycling of CO2 to the GT. When equal GT efficiency was assumed for combustion with normal air and with CO2 enriched air, the membranes' technical performance was comparable with that of MEA. The capital costs of the, Applied Sciences

This work compares the part load techno-economic performance of CO2 capture from a combined cycle gas turbine (CCGT) using a membrane configuration with selective CO2 recycle and using monoethanolamine (MEA) solvent, under the assumption of flexible power plant dispatch. This is the first time that the techno-economic performance of CO2 capture technologies is compared assuming a flexible dispatch profile, and the assessment was done using a comprehensive, new, part load assessment approach. Analyzing the part load performance of CO2 capture and storage (CCS) technologies is relevant because of significant changes in our power systems, dramatically reducing the utilization of thermal power plants. The technical performance of the configurations with and without CCS was simulated at steady state, at operating points between maximum continuous rating (100% gas turbine loading) and minimum stable load (35% gas turbine loading). The performance at these operating points was then aggregated into weighted averages to produce single performance indicators (specific CO2 intensity, specific primary energy per tonne of CO2 avoided (SPECCA), and levelized cost of electricity (LCOE)) over the dispatch profile of the power plant. The technical performance of the MEA configuration was favorable over the membrane configuration over the whole CCGT loading range. The MEA SPECCA increased from 3.02 GJ/(t of CO2) at 100% GT loading to 3.65 GJ/(t of CO2) at 35% GT loading; the membrane SPECCA increased from 3.35 to 4.20 GJ/(t of CO2). The higher SPECCA of the membrane configuration is caused by the reduced gas turbine efficiency, due to the selective recycling of CO2 to the GT. When equal GT efficiency was assumed for combustion with normal air and with CO2 enriched air, the membranes' technical performance was comparable with that of MEA. The capital costs of the

OBJECTIVES: Despite claims of feasibility, to date no study has examined the effect of systematic bilateral internal mammary artery (BIMA) use in a large cohort of real-world unselected patients. The CATHolic University EXtensive BIMA Grafting Study (CATHEXIS) registry was designed to assess the feasibility and safety of systematic BIMA grafting. METHODS: The CATHEXIS was a single-centre, prospective, observational, propensity-matched study. The study was supposed to include 2 arms of 500 patients each: a prospective arm and a retrospective arm. The prospective arm included almost all patients referred for coronary artery bypass grafting (CABG) at our institution after the start of the CATHEXIS with very few exceptions. BIMA would have been used in all these patients. The retrospective arm included patients submitted to CABG before the start of the CATHEXIS and propensity matched to the prospective group (average BIMA use 50%; the radial artery was extensively used). Safety analyses were scheduled after enrolment of 200, 300 and 400 BIMA patients. RESULTS: After the first 226 patients, the BIMA use percentage was 88.5% (200 of 226). In 178 (89%) patients, mammary arteries were used as Y graft. Postoperative mortality was 2%, and incidence of perioperative myocardial infarction, graft failure and sternal complications were 3.5%, 3% and 5.5%, respectively. No perioperative stroke occurred. The incidence of major adverse cardiac events (particularly graft failure and sternal complications) in the BIMA arm were significantly higher than those in the propensity-matched cohort; the study was stopped for safety. CONCLUSIONS: In a real world setting the systematic use of BIMA was associated with a higher incidence of perioperative adverse events (particularly sternal complications). Individualization of the revascularization strategy and use of alternative arterial conduits are probably preferable to systematic use of BIMA.

The absorption between aqueous NH3 and CO2 is studied using the Wetted Wall Column in order to show the effect of the solvent condition on the rate of reaction. A total of 27 different cases are investigated in the region defined by temperatures from 15 °C to 35 °C, NH3 concentrations from 5% to 15% and CO2 loadings from 0.2 to 0.6. The paper reports the data measured during the experiments, the experimental apparatus description and the experimental procedure. The data here presented are both the raw data measured with their uncertainty and the final value of the overall mass transfer coefficient. The overall mass transfer coefficient is the result of the raw data treatment explained in the research paper related to this data. The data here reported are analyzed in the paper by Lillia et al. (2018) [1].

This paper focuses on carbon capture in an Ultra Super Critical power plant. The technology selected for CO2 capture is based on cooled ammonia scrubbing in post-combustion mode, as recently investigated by the authors in another work. Here, a rate-based approach is adopted. In detail, a specific primary energy consumption for CO2 avoided (SPECCA) of 2.77 MJ/kgCO2 is calculated in case of 85% of CO2 capture, with an ultimate power plant efficiency of 37.27%.

Post-combustion carbon capture technologies seem to be necessary to realize the CO2 mitigation policies internationally shared for the next future, despite none of them appears to be ready for full-scale applications. This work considers the aqueous ammonia based process for a coal-fired Ultra Super Critical power plant. Two layouts are simulated with Aspen Plus employing the recently recalibrated Extended UNIQUAC thermodynamic model. The first one operates at chilling conditions, which yield to salt precipitation, and is taken as reference because already analyzed in previous studies. The second layout operates at cooled conditions, which does not yield any salt precipitation. The Chilled layout reveals low specific heat duty and SPECCA equal to 2.2 and 2.86 MJ/kgco2, respectively. In contrast, the Cooled layout presents a higher specific heat duty of almost 3 MJ/kgco2 but, importantly, a lower SPECCA of 2.58 MJ/kgco2. The latter layout is a better choice also from the perspective of the plant operation since it does not present the salt precipitation.

The choice of conduits for surgical revascularization in patients with aortic coarctation can be puzzling, as the internal thoracic arteries can be dilated, atherosclerotic and unsuitable for grafting. Reports in the literature are controversial: in some cases, the internal thoracic artery was not suitable for revascularization, while in others, it could be used with discordant outcomes. Here, we review the literature on the subject.

BACKGROUND: Internal thoracic arteries (ITAs) are frequently anastomosed to the coronary circulation for bypass grafting. The purpose of this research was to investigate in vivo the long-term morphofunctional changes of ITAs after their use as coronary artery bypass conduits, by comparing the morphological features and vasoreactivity of the grafted left ITA (LITA) with the native, nonharvested right ITA (RITA) in the same patient. METHODS AND RESULTS: At least 10 years after surgery, in 10 patients, LITA graft and nonharvested RITA were assessed by quantitative angiography and frequency-domain optical tomography. Endothelium-dependent and independent vasodilation was tested by selective infusion of acetylcholine and isosorbide dinitrate. Quantitative angiography showed that baseline mean diameter of LITA graft was significantly smaller than that of RITA (2.59 mm [2.29-3.04] versus 3.05 mm [2.75-3.32]; P=0.01). LITA showed a significant intimal thickening (P=0.05) and a nonsignificant medial thinning (P=0.22) compared with RITA, leading to an increased intima-media ratio (intima-media ratio, 0.72 [0.53-0.91] versus 0.23 [0.12-0.38]; P=0.02). The intima-media ratio correlated inversely with the vasodilatatory response in RITA (r=-0.68, P=0.03 for acetylcholine and r=-0.62, P=0.05 for isosorbide dinitrate) but not in LITA (r=-0.18, P=0.63 for acetylcholine and r=-0.11, P=0.75 for isosorbide dinitrate). CONCLUSIONS: Ten years after implantation to the coronary circulation, LITA grafts show intimal thickening, increased intima/media ratio, and maintained endothelium-derived vasodilation. These changes are likely to be an adaptive answer to the different flow dynamics typical of coronary circulation

The choice of conduits for surgical revascularization in patients with aortic coarctation can be puzzling, as the internal thoracic arteries can be dilated, atherosclerotic and unsuitable for grafting. Reports in the literature are controversial: in some cases, the internal thoracic artery was not suitable for revascularization, while in others, it could be used with discordant outcomes. Here, we review the literature on the subject.

Many alternatives are being investigated for the carbon capture, but none appears to have been proved as the choice for full-scale applications. This work considers the Chilled Ammonia Process for coal-fired Ultra Super Critical power plants. Three layouts are simulated with Aspen Plus and the Extended UNIQUAC thermodynamic model. Compared to a traditional layout, stripping of the wash water of the absorber or, better, splitting the rich solution between the middle and the top of the column limits greatly the ammonia slip. Moreover, splitting the regeneration over two levels reduces substantially the electric loss due to stream extraction from the turbine. The simulations show that the net electric efficiency drops from 45.5% to 33.5-34.5%, the SPECCA index is 3.8-4.3 MJth kgCO2–1 and the heat duties are 2.7-2.9 MJth kgCO2–1. The performances may improve greatly upon optimization of the parameters

Chrysotile is the fibrous mineral of the serpentine group, whichis developed from the alteration of magnesium silicates, olivine,pyroxene and amphibole especially. The sheet structure iscurved into scrolls or hollow cylinders that form individualfibers, which are responsible for its properties as asbestos. Chrysotile has been used extensively in industrial materials, however, asbestos inhalation can cause lung diseases such asmesothelioma and asbestosis. Exposure to asbestos can be from three different sources: laboral, domestic and environmental. Asbestos fibers can be introducedinto the air or natural water from the erosion of rocks rich in asbestos asbestos, manufactured materials, or disposal of industrialasbestos wastes.The purpose of this paper is to study morphologic and size changes of fibers, simulating exogenous conditions in laboratory. Todeterminate the degradation of the mineral in in natural conditions in the course of time and to analyze how the fibers modifytheir size and morphology until the critical for human health are reached, El crisotilo es un mineral del grupo de la serpentina que se desarrolla a partir de la alteración de olivinos, piroxenos yanfíboles. Posee una estructura en donde las capas de silicato se disponen en forma de tubos o cilindros concéntricos oenrollados. Esto genera el hábito característico de los minerales asbestiformes.El cristolilo se ha utilizado en numerosos productos industriales. Sin embargo a su gran utilidad hay que considerar su altatoxicidad ya que puede producir enfermedades pulmonares, tales como mesotelioma o asbestosis, de forma directa o indirecta.La exposición al asbesto puede ser de tres fuentes conocidas: laboral, doméstica y ambiental. Las fibras pueden pasar al aire oal agua no sólo debido a la degradación de los productos manufacturados sino también por la movilidad de estos mineralesdesde los depósitos naturales.El objetivo de este trabajo fue realizar una evaluación de los cambios morfológicos y de tamaño de las fibras de crisotilomuestreadas en campo, simulando en laboratorio condiciones naturales. A partir de los resultados obtenidos se evaluó ladegradación del mineral en el tiempo en condiciones variablesy se analizó cómo las fibras modifican su tamaño y morfologíahasta alcanzar las condiciones críticas para la salud humana

Following the experience of cardiac surgeons with homografts in the treatment of infective aortic valve endocarditis, cardiovascular surgeons have investigated in situ revascularization by means of homografts in the management of vascular prosthetic graft infections. Preliminary results are encouraging, but their late fate in long-term follow-up and the influence of preservation techniques are still under investigation. This article reports the experience of the Italian Collaborative Vascular Homograft Group, with the use of fresh and cryopreserved arterial homografts for the treatment of prosthetic graft infections. Between March 1994 and December 1996, 44 patients with prosthetic graft infection were treated with homografts (13 preserved at 4°C, 31 cryopreserved). The mean age of the patients was 65 years. Emergency surgical procedures were performed in eight patients (18%). Sepsis was diagnosed in 11 patients, aortoenteric fistula in 13, and false aneurysms in 10. Staphylococcus was the main cause of infection. The types of vascular reconstruction with homograft were: 32 aortobifemoral, 3 aortoaortic, 2 iliofemoral, 4 peripheral, and 3 axillobifemoral. Human lymphocyte antigen (HLA) and antibody (ABO) blood group system compatibility between donors and recipients was not respected. The mean duration of follow-up was 15 months (range 1–33). Clinical and duplex scanning evaluations were routinely performed. Computed tomography (CT) or magnetic resonance (MR) scanning or arteriography were performed on the basis of duplex scanning results. There were six deaths during the early postoperative period (30 days) with a mortality rate of 13.6%. During the follow-up there were five late deaths with a mortality rate of 11.4%. Eight patients had graft occlusion. Three cases were successfully treated with thrombectomy. Two cases were successfully treated with femoropopliteal bypass with autologous vein. In three cases leg amputation was necessary. The results of fresh and cr

The metasedimentary sequences of the Sierras Pampeanas are intruded by a series of Hercynian granitoids ranging from granitic to tonalitic in composition. The most evolved granitoids show alkali granitic characteristics. Pegmatites with very different zoning and mineralogical characteristics are found in the granitoids and in the country rocks. Their origin is attributed to extreme differentiation by fractional crystallisation of a granitic magma. The economic potential for rare metals is evaluated in geochemical discrimination diagrams; some of the pegmatites are not only highly differentiated in terms of alkalis but are also promising targets for small-scale mining of Ta and, to some extent, Sn., The metasedimentary sequences of the Sierras Pampeanas are intruded by a series of Hercynian granitoids ranging from granitic to tonalitic in composition. The most evolved granitoids show alkali granitic characteristics. Pegmatites with very different zoning and mineralogical characteristics are found in the granitoids and in the country rocks. Their origin is attributed to extreme differentiation by fractional crystallisation of a granitic magma. The economic potential for rare metals is evaluated in geochemical discrimination diagrams; some of the pegmatites are not only highly differentiated in terms of alkalis but are also promising targets for small-scale mining of Ta and, to some extent, Sn.

Negli ultimi decenni la sempre più crescente competitività dei mercati e la conseguente ricerca di miglioramento delle performance aziendali ha incentivato lo studio e l’analisi dei processi produttivi. In questo ambito la manutenzione degli impianti industriali gioca un ruolo fondamentale, acquistando quindi un crescente e motivato interesse da parte della comunità scientifica. Questo scenario ha favorito lo svilupparsi di numerose teorie e strategie che mirano a ottimizzare i principali attori della gestione della manutenzione; affidabilità degli asset e costi. Inoltre, la manutenzione è una funzione sempre più strategica anche in virtù del ruolo che ha nella gestione di fattori non prettamente produttivi, come la sicurezza, la tutela ambientale, il rispetto dei parametri di legge e la qualità. L’obiettivo principale di questo elaborato è definire un sistema di gestione della manutenzione standardizzato e volto al miglioramento continuo. Il punto di partenza è l’analisi della criticità delle varie attrezzature, questo permette di comprendere su quali macchinari è prioritario concentrare le risorse a disposizione. Per poi agire in modo organizzato avendo definito le “best practise”, promuovendo una sempre maggiore standardizzazione delle procedure. L’approccio da perseguire è quello integrato, focalizzato alla ricerca del miglioramento continuo delle performance, che si pone come obiettivo quello di migliorare la disponibilità delle attrezzature riducendo il numero di guasti. Partendo dalla necessità di riorganizzazione della manutenzione si è sviluppata una possibile applicazione della TPM, tale filosofia declinata e adattata alle esigenze del sistema produttivo SKF prende il nome di Maintenance Excellence. Verranno inoltre descritti altri strumenti complementari che abbinati alla TPM permettono di ottenere i migliori risultati, in particolare si vuole sottolineare l’importanza dell’utilizzo di software di supporto del tipo CMMS.

Negli ultimi decenni la sempre più crescente competitività dei mercati e la conseguente ricerca di miglioramento delle performance aziendali ha incentivato lo studio e l’analisi dei processi produttivi. In questo ambito la manutenzione degli impianti industriali gioca un ruolo fondamentale, acquistando quindi un crescente e motivato interesse da parte della comunità scientifica. Questo scenario ha favorito lo svilupparsi di numerose teorie e strategie che mirano a ottimizzare i principali attori della gestione della manutenzione; affidabilità degli asset e costi. Inoltre, la manutenzione è una funzione sempre più strategica anche in virtù del ruolo che ha nella gestione di fattori non prettamente produttivi, come la sicurezza, la tutela ambientale, il rispetto dei parametri di legge e la qualità. L’obiettivo principale di questo elaborato è definire un sistema di gestione della manutenzione standardizzato e volto al miglioramento continuo. Il punto di partenza è l’analisi della criticità delle varie attrezzature, questo permette di comprendere su quali macchinari è prioritario concentrare le risorse a disposizione. Per poi agire in modo organizzato avendo definito le “best practise”, promuovendo una sempre maggiore standardizzazione delle procedure. L’approccio da perseguire è quello integrato, focalizzato alla ricerca del miglioramento continuo delle performance, che si pone come obiettivo quello di migliorare la disponibilità delle attrezzature riducendo il numero di guasti. Partendo dalla necessità di riorganizzazione della manutenzione si è sviluppata una possibile applicazione della TPM, tale filosofia declinata e adattata alle esigenze del sistema produttivo SKF prende il nome di Maintenance Excellence. Verranno inoltre descritti altri strumenti complementari che abbinati alla TPM permettono di ottenere i migliori risultati, in particolare si vuole sottolineare l’importanza dell’utilizzo di software di supporto del tipo CMMS.