a diagnostics tool for aero engines health monitoring using machine learning technique

Abstract In this work an integrated heath monitoring platform is proposed and developed for performance analysis and degradation diagnostics of gas turbine engines. The aim is to link engine measurable data to its health status. A numerical tool has been implemented in order to calculate engine performance in design condition and to create a database of expected vales. Then different degradation levels have been introduced in the two main components, compressor and turbine of a single spool turbojet and the diagnostics instruments have been trained to detect the component fault. In order to evaluate the performance prediction two different machine learning based techniques, namely, artificial neural network (ANN) and support vector machine (SVM) have been compared. Synthetic data generation has been carried out to show how the degradation effects can affect the engine performance. The two main degradation causes considered are the compressor fouling and turbine erosion. The machine learning techniques were applied with two aims: aero-engine performance prediction and health diagnostics. The study was carried out based on three samples flights, whose data were used for the training and testing process of the prediction and diagnostics tools. The knowledge and the continuous monitoring of the engine health status can be crucial for maintenance and fleet management operations

Temporal pattern of expression and colocalization of microglia/macrophage phenotype markers following brain ischemic injury in mice

<p>Abstract</p> <p>Background</p> <p>Emerging evidence indicates that, similarly to what happens for peripheral macrophages, microglia can express different phenotypes depending on microenvironmental signals. In spite of the large literature on inflammation after ischemia, information on M/M phenotype marker expression, their colocalization and temporal evolution in the injured brain is lacking. The present study investigates the presence of microglia/macrophage phenotype markers, their temporal expression, whether they are concomitantly expressed by the same subpopulation, or they are expressed at distinct phases or locations in relation to the ischemic lesion.</p> <p>Methods</p> <p>Volume of ischemic lesion, neuronal counts and TUNEL staining were assessed in C57Bl/6 mice at 6-12-24-48 h and 7d after permanent occlusion of the middle cerebral artery. At the same time points, the expression, distribution in the lesioned area, association with a definite morphology and coexpression of the microglia/macrophage markers CD11b, CD45, CD68, Ym1, CD206 were assessed by immunostaining and confocal microscopy.</p> <p>Results</p> <p>The results show that: 1) the ischemic lesion induces the expression of selected microglia/macrophage markers that develop over time, each with a specific pattern; 2) each marker has a given localization in the lesioned area with no apparent changes during time, with the exception of CD68 that is confined in the border zone of the lesion at early times but it greatly increases and invades the ischemic core at 7d; 3) while CD68 is expressed in both ramified and globular CD11b cells, Ym1 and CD206 are exclusively expressed by globular CD11b cells.</p> <p>Conclusions</p> <p>These data show that the ischemic lesion is accompanied by activation of specific microglia/macrophage phenotype that presents distinctive spatial and temporal features. These different states of microglia/macrophages reflect the complexity of these cells and their ability to differentiate towards a multitude of phenotypes depending on the surrounding micro-environmental signals that can change over time. The data presented in this study provide a basis for understanding this complex response and for developing strategies resulting in promotion of a protective inflammatory phenotype.</p

Mammographic breast density in infertile and parous women

BACKGROUND: Mammographic breast density is a useful marker for breast cancer risk, as breast density is considered one of the strongest breast cancer risk factors. The study objective was to evaluate and compare mammographic breast density in infertile and parous women, as infertility may be associated with high breast density and cancer occurrence. METHODS: This study evaluated mammographic breast density using two different systems, BIRADS and Boyd. A selected patient population of 151 women with primary infertility (case group) was compared to 154 parous women who had at least one previous pregnancy (control group). Both groups were premenopausal women aged ≥ 35. RESULTS: Evaluation of mammographic features showed that 66.9% of case group patients and 53.9% of control group patients were classified BIRADS-3/BIRADS-4; p < 0.05. Adjusted Odds ratio for the case group in the categories BIRADS-3/BIRADS-4 was 1.78 (95% CI: 1.10-2.89). Using the Boyd classification system, 53.6% of case group patients and 31.8% of control group patients were classified E/F; p < 0.05. Adjusted Odds ratio for case group patients in Boyd categories E/F was 2.05 (95 % CI: 1.07-3.93). CONCLUSIONS: Both systems yielded a higher percentage of increased breast density in the case group. Boyd and BIRADS classification systems indicate to what extend breast cancer lesions may be missed on mammography due to masking by dense tissue. Therefore, patients with a high BIRADS or Boyd score should undergo further investigation

Experimental and Numerical Investigations on the Effect of Different Air-Fuel Mixing Strategies on the Performance of a Lean Liquid Fueled Swirled Combustor☆

Abstract In the present work the performance of a multipoint lean direct injection strategy for low emission aero-propulsion systems has been experimentally and numerically investigated, and compared with the single point injection strategy. A swirler liquid fueled combustor was designed and used in experiments to investigate the flame behavior in lean and ultra-lean conditions for both the single-point and the multi-points injection strategies. Multipoint injection has been realized injecting an amount of fuel upstream the swirler inlet and using also the central injector as a "pilot" injection. As regarding the experimental facilities, the combustor is equipped with four optical accesses for high speed flame imaging and with pressure and temperature sensors. Experimental data on flame characteristics and pollutant emissions are obtained. The characterization of the flame was realized using intensified high rate CCD camera for the acquisition in the ultraviolet spectral range. In front of the camera various combinations of optical filters were installed to selectively record the respective chemiluminescent species (OH* and CH*). Computational fluid dynamic (CFD) simulations were also performed for a deeper understanding of the flame characteristics under the two injection strategies. The typical combustor operations were reproduced to more deeply understand the differences between the injection modes and the related flame patterns. The numerical results show different temperature and species fields predicted for the non-premixed and the partially premixed cases and furnish relevant information about the fluid dynamics in the combustion chamber in both the injection conditions

Making the Communication of CCS more "human"

CCS communication has proven a tough challenge, particularly for the difficulty in raising interest for the technology, which is still unknown to the majority of the population, and for the complexity of conveying information about its potential for reducing emissions. In this paper we present a research based effort for bringing CCS nearer to people, through visual material developed taking into account emotional needs related to the technology. The production of a short introductory film on CCS is illustrated and its testing with a sample of 700 high school students

Improvement of lean flame stability of inverse methane/air diffusion flame by using coaxial dielectric plasma discharge actuators

none6noAbstract Low environmental impact is a main issue in the design of novel combustion systems, as aircraft engines. In this context, the present work investigates the possibility to increase the combustion efficiency of a lean flame through the use of sinusoidally driven dielectric barrier discharge (DBD) plasma actuator. The effect of the plasma discharge on a lean non premixed methane/air flame in a Bunsen-type burner has been studied for two different configurations: the normal diffusive flame (NDF) and the inverse diffusive flame (IDF). The flame behavior was investigated by chemiluminescence imaging through an intensified \CCD\ camera. Optical filters were installed in front of the camera, aiming to selectively record signal from the chemiluminescent species OH*, CH*, or CO2*. This allowed evaluating the changes occurring in presence of plasma actuation in term of flame emissions. It was shown that the plasma effects are significantly influenced by the burner and \DBD\ configuration. A plasma power of approximately 25 W permitted to increase the air mass flow rate at which lean blowout appears; it rose up to 30% for low methane flow rate and up to 10% at high fuel flow rate.partially_openDe Giorgi, Maria Grazia; Ficarella, Antonio; Sciolti, Aldebara; Pescini, Elisa; Campilongo, Stefano; Di Lecce, GiorgioDE GIORGI, Maria Grazia; Ficarella, Antonio; Sciolti, Aldebara; Pescini, Elisa; Campilongo, Stefano; DI LECCE, Giorgi

Distinctive HLA-II association with primary biliary cholangitis on the Island of Sardinia

Background: The HLA DRB1*08 allele associated with primary biliary cholangitis (PBC) among Caucasians is of low frequency in the Sardinian population. Objective: The aim of our study was to type a cohort of PBC patients from the island of Sardinia for HLA class II antigens. Methods: Twenty Sardinian patients affected by PBC, 14 with autoimmune hepatitis (AIH) and 89 healthy controls (HCs) were typed for HLA class II alleles by dot-blot analysis. Results: The PBC-associated HLA DRB1*08 allele was detected in none of the studied individuals. The DRB1*0301–DQB1*0201 was the prevalent HLA haplotype, detected in 19 (47.5%) out of 40 PBC haplotypes (OR = 3.0; 95% CI 1.5–6.2) and in 11 (39.3%) out of 28 AIH haplotypes (OR = 2.2; 95% CI 0.94–5.0), but in only 41 (23%) out of 178 HC haplotypes. Moreover, PBC patients showed an increased frequency of homozygosity for the DQB1*0201 allele (35% compared with 6.7% of the HCs; OR = 7.5; 95% CI 2.2–25.7). The frequency of the DRB1*11 allele in the PBC group was about half of that seen in the Sardinian HCs (7.5% vs 15.7%) (p = ns). Conclusions: Our study confirmed the low frequency of the HLA DRB1*08 allele among Sardinians, either in the general population or PBC patients. The high prevalence of the HLA DRB1*0301–DQB1*0201 haplotype is a distinctive genetic feature of PBC among Sardinians. Our study strengthens the hypothesis that still unknown genetic, epigenetic, and environmental factors must be involved in the pathogenesis of different HLA-associated liver diseases, and it represents a pathfinder that warrants exploration in a future extensive study

Mobile-Bearing Total Ankle Replacement In Vivo Kinematic Assessment: A Prospective Study Protocol

Total ankle prosthesis as a surgical solution in the case of end-stage osteoarthritis has seen a considerable increase in the last two decades. This study protocol arises from the need to understand the in vivo kinematics of mobile-bearing, flat tibial component total ankle replacement, evaluating the real range of motion and the reciprocal relationships between the components during normal motor tasks through the use of model-based radio-stereometric analysis (MB-RSA). In addition, pre- and post-operative evaluation of walking kinematics with inertial motion sensors, proprioception through a dedicated workstation, and clinical outcomes are discussed. We expect that based on our study protocol researchers will be able to improve future prosthetic designs and validate the setup of MB-RSA, as well as to understand "how an ankle prosthesis moves" once implanted in the patient

Lectin Pathway of Complement Activation Is Associated with Vulnerability of Atherosclerotic Plaques

Inflammatory mechanisms may be involved in atherosclerotic plaque rupture. By using a novel histology-based method to quantify plaque instability here, we assess whether lectin pathway (LP) of complement activation, a major inflammation arm, could represent an index of plaque instability. Plaques from 42 consecutive patients undergoing carotid endarterectomy were stained with hematoxylin-eosin and the lipid core, cholesterol clefts, hemorrhagic content, thickness of tunica media, and intima, including or not infiltration of cellular debris and cholesterol, were determined. The presence of ficolin-1, -2, and -3 and mannose-binding lectin (MBL), LP initiators, was assessed in the plaques by immunofluorescence and in plasma by ELISA. LP activation was assessed in plasma by functional in vitro assays. Patients presenting low stenosis (≤75%) had higher hemorrhagic content than those with high stenosis (>75%), indicating increased erosion. Increased hemorrhagic content and tunica media thickness, as well as decreased lipid core and infiltrated content were associated with vulnerable plaques and therefore used to establish a plaque vulnerability score that allowed to classify patients according to plaque vulnerability. Ficolins and MBL were found both in plaques’ necrotic core and tunica media. Patients with vulnerable plaques showed decreased plasma levels and intraplaque deposition of ficolin-2. Symptomatic patients experiencing a transient ischemic attack had lower plasma levels of ficolin-1. We show that the LP initiators are present within the plaques and their circulating levels change in atherosclerotic patients. In particular, we show that decreased ficolin-2 levels are associated with rupture-prone vulnerable plaques, indicating its potential use as marker for cardiovascular risk assessment in atherosclerotic patients

Regulation of microRNAs in satellite cell renewal, muscle function, sarcopenia and the role of exercise

Sarcopenia refers to a condition of progressive loss of skeletal muscle mass and function associated with a higher risk of falls and fractures in older adults. Musculoskeletal aging leads to reduced muscle mass and strength, affecting the quality of life in elderly people. In recent years, several studies contributed to improve the knowledge of the pathophysiological alterations that lead to skeletal muscle dysfunction; however, the molecular mechanisms underlying sarcopenia are still not fully understood. Muscle development and homeostasis require a fine gene expression modulation by mechanisms in which microRNAs (miRNAs) play a crucial role. miRNAs modulate key steps of skeletal myogenesis including satellite cells renewal, skeletal muscle plasticity, and regeneration. Here, we provide an overview of the general aspects of muscle regeneration and miRNAs role in skeletal mass homeostasis and plasticity with a special interest in their expression in sarcopenia and skeletal muscle adaptation to exercise in the elderly