On the role of Prognostics and Health Management in advanced maintenance systems

The advanced use of the Information and Communication Technologies is evolving the way that systems are managed and maintained. A great number of techniques and methods have emerged in the light of these advances allowing to have an accurate and knowledge about the systems’ condition evolution and remaining useful life. The advances are recognized as outcomes of an innovative discipline, nowadays discussed under the term of Prognostics and Health Management (PHM). In order to analyze how maintenance will change by using PHM, a conceptual model is proposed built upon three views. The model highlights: (i) how PHM may impact the definition of maintenance policies; (ii) how PHM fits within the Condition Based Maintenance (CBM) and (iii) how PHM can be integrated into Reliability Centered Maintenance (RCM) programs. The conceptual model is the research finding of this review note and helps to discuss the role of PHM in advanced maintenance systems.EU Framework Programme Horizon 2020, 645733 - Sustain-Owner - H2020-MSCA-RISE-201

Customer-oriented risk assessment in Network Utilities

For companies that distribute services such as telecommunications, water, energy, gas, etc., quality perceived by the customers has a strong impact on the fulfillment of financial goals, positively increasing the demand and negatively increasing the risk of customer churn (loss of customers). Failures by these companies may cause customer affection in a massive way, augmenting the intention to leave the company. Therefore, maintenance performance and specifically service reliability has a strong influence on financial goals. This paper proposes a methodology to evaluate the contribution of the maintenance department in economic terms, based on service unreliability by network failures. The developed methodology aims to provide an analysis of failures to facilitate decision making about maintenance (preventive/predictive and corrective) costs versus negative impacts in end-customer invoicing based on the probability of losing customers. Survival analysis of recurrent failures with the General Renewal Process distribution is used for this novel purpose with the intention to be applied as a standard procedure to calculate the expected maintenance financial impact, for a given period of time. Also, geographical areas of coverage are distinguished, enabling the comparison of different technical or management alternatives. Two case studies in a telecommunications services company are presented in order to illustrate the applicability of the methodology

Highly charged ions: optical clocks and applications in fundamental physics

Recent developments in frequency metrology and optical clocks have been based on electronic transitions in atoms and singly charged ions as references. These systems have enabled relative frequency uncertainties at a level of a few parts in $10^{-18}$. This accomplishment not only allows for extremely accurate time and frequency measurements, but also to probe our understanding of fundamental physics, such as variation of fundamental constants, violation of the local Lorentz invariance, and forces beyond the Standard Model of Physics. In addition, novel clocks are driving the development of sophisticated technical applications. Crucial for applications of clocks in fundamental physics are a high sensitivity to effects beyond the Standard Model and Einstein's Theory of Relativity and a small frequency uncertainty of the clock. Highly charged ions offer both. They have been proposed as highly accurate clocks, since they possess optical transitions which can be extremely narrow and less sensitive to external perturbations compared to current atomic clock species. The selection of highly charged ions in different charge states offers narrow transitions that are among the most sensitive ones for a change in the fine-structure constant and the electron-to-proton mass ratio, as well as other new physics effects. Recent advances in trapping and sympathetic cooling of highly charged ions will in the future enable high accuracy optical spectroscopy. Progress in calculating the properties of selected highly charged ions has allowed the evaluation of systematic shifts and the prediction of the sensitivity to the "new physics" effects. This article reviews the current status of theory and experiment in the field.Comment: 53 pages, 16 figures, submitted to RM

Women and port painting: Collection of Superior Council of Sports (Spain)

El objetivo del presente estudio es analizar cómo es representada la mujer en la pintura deportiva, según la selección avalada por el Consejo Superior de Deportes, que aparece en “Deporte, arte y literatura”. El análisis cuantitativo muestra a la mujer en un número muy reducido de obras y caracterizada como joven y delgada. El análisis cualitativo identifica un tratamiento sexista y discriminatorio de la mujer, pintada desde un enfoque androcéntrico: bien como objeto sexual, bien como personaje pasivo, secundario y en función del personaje masculino. En las escasas ocasiones en las que la mujer aparece como personaje activo y central de la obra, aparece con énfasis estético y expresivo del movimiento, lo que caracteriza las actividades físico-deportivas que la ideología de género considera femeninas. En conclusión la pintura sobre el deporte ofrece una imagen sesgada y desigual, reproduciendo los estereotipos respecto a la masculinización del deporte y relega la presencia femeninaThe aim of this study is to analyse how women are represented in the sports paintings, taking as reference a selection of works supported by the Superior Council of Sports, collected in the publication "Sport, art and literature". Quantitative analysis note that the female figure appears in a very small number of works and they are represented young and thin. Qualitative analysis allows to identify a sexist treatment and discriminatory of women, who is painted from an androcentric perspective: a sexual object, passive character, secondary and based on the male character. When the women appears as an active character and central of the work, they are marked by the emphasis in the aesthetic aspects and expressive of the movement, what defines the physical-sports activities that the gender ideology considers to be female. In conclusion, sport painting offers an image skewed and uneven, reproducing stereotypes regarding the masculinization of the sport and the limited nature of female sport

A framework for effective management of condition based maintenance programs in the context of industrial development of E-Maintenance strategies

CBM (Condition Based Maintenance) solutions are increasingly present in industrial systems due to two main circumstances: rapid evolution, without precedents, in the capture and analysis of data and significant cost reduction of supporting technologies. CBM programs in industrial systems can become extremely complex, especially when considering the effective introduction of new capabilities provided by PHM (Prognostics and Health Management) and E-maintenance disciplines. In this scenario, any CBM solution involves the management of numerous technical aspects, that the maintenance manager needs to understand, in order to be implemented properly and effectively, according to the company’s strategy. This paper provides a comprehensive representation of the key components of a generic CBM solution, this is presented using a framework or supporting structure for an effective management of the CBM programs. The concept “symptom of failure”, its corresponding analysis techniques (introduced by ISO 13379-1 and linked with RCM/FMEA analysis), and other international standard for CBM open-software application development (for instance, ISO 13374 and OSA-CBM), are used in the paper for the development of the framework. An original template has been developed, adopting the formal structure of RCM analysis templates, to integrate the information of the PHM techniques used to capture the failure mode behaviour and to manage maintenance. Finally, a case study describes the framework using the referred template.Gobierno de Andalucía P11-TEP-7303 M

X-ray flares on the UV Ceti-type star CC Eridani: a "peculiar" time-evolution of spectral parameters

Context: Weak flares are supposed to be an important heating agent of the outer layers of stellar atmospheres. However, due to instrumental limitations, only large X-ray flares have been studied in detail until now. Aims: We used an XMM-Newton observation of the very active BY-Dra type binary star CC Eri in order to investigate the properties of two flares that are weaker than those typically studied in the literature. Methods: We performed time-resolved spectroscopy of the data taken with the EPIC-PN CCD camera. A multi-temperature model was used to fit the spectra. We inferred the size of the flaring loops using the density-temperature diagram. The loop scaling laws were applied for deriving physical parameters of the flaring plasma. We also estimated the number of loops involved in the observed flares. Results: A large X-ray variability was found. Spectral analysis showed that all the regions in the light curve, including the flare segments, are well-described by a 3-T model with variable emission measures but, surprisingly, with constant temperatures (values of 3, 10 and 22 MK). The analysed flares lasted ~ 3.4 and 7.1 ks, with flux increases of factors 1.5-1.9. They occurred in arcades made of a few tens of similar coronal loops. The size of the flaring loops is much smaller than the distance between the stellar surfaces in the binary system, and even smaller than the radius of each of the stars. The obtained results are consistent with the following ideas: (i) the whole X-ray light curve of CC Eri could be the result of a superposition of multiple low-energy flares, and (ii) stellar flares can be scaled-up versions of solar flares.Comment: 14 pages, 12 figures. Accepted for publication in Astronomy & Astrophysic

Componentes acetabulares no cementados: resultados preliminares con los modelos PCA y Poro-palcar

Se comparan los resultados clínicos y radiológicos a corto plazo referente s al component e acetabula r de 62 artroplastia s totale s de cader a no cementadas. Treinta y tres implante s correspondían al modelo Poro-palcar y 29 al modelo PCA. La edad media en el momento de la intervención fue de 62 años (ds=9.6). El tiempo medio de seguimient o postoperatorio fue de un año y siet e mese s (máximo 3 años y mínimo un año). Para la valoración clínica se utiliza el test de Harris. La puntuación final total alcanza 88.7 puntos (ds=6.9) para el modelo PCA y 83.5 puntos (ds=13.2) para el poropalear. Los resultados clínicos fueron excelente s (80-100 puntos) en el 93% de los implante s PCA y en el 67% poro-palear (p<0.01), con una remisión completa del dolor en más del 90% de los casos para ambos modelos. La mejoría de la capacidad funcional fue significativament e mayo r en los enfermo s intervenido s con e l model o PCA. En cuanto a los resultados radiológicos, no hubo signos significativos de migración acetabular en ninguno de los modelos. Respecto a la aparición de radiolucencias, no se detectaron en el 72% de las copas PCA y en 60% de las copas poro-palear, presentando el resto radiolucencias de hasta 2 mm, lo cual indica una mejor osteointegración de las copas PCA respecto de las poro-palear.The clinical and roentgenographi c short-term results regarding the acetabular component wer e aveluated in a series of 62 noncemented total hip arthroplastie s in whic h eithe r the PCA cup (29 cases) or the poro-palcar mode l (33 cases) wer e implanted. At the time of surgery, the mean age of patients wa s 62 year s (ds=9.6). The average follow-up wa s 1 year and 7 months, ranging from 1 to 3 years. Clinical assesment wa s performed usin g the Harris'score . At review, the total scor e reache d 88.7 points (ds=6.9) for the PCA model and 83.5 (ds+13.2) for the poro-palcar cup. Excellent clinical results (80-100points) wer e found in 93% of the patients operated on wich the PCA cup and in 67% of those with the poro-palcar model (p<0.01). Pain was removed in more than 90% of the case s independently of the cup model used. The improvement of function was significantly better in patients receiving the PCA cup. There was not acetabular migration in any of the groups. Periacetabular radiolucent images wer e not detected in 72% of PCA case s an in 60% of the poro-palcar group. In case s with radiolucent images, these don't exceded more than 2 mm. Osteointegration seens to be better for the PCA cups than for the poro-palcar models

Artroplastia total de cadera no cementada : resultados a corto plazo con los componentes femorales de los modelos poro-palcar y PCA

Se presentan los resultados clínicos y radiológicos, a corto plazo, referentes al componente femoral de una serie de 62 artroplastias totales de cadera no cementadas. Treinta y tres correspondían al modelo PORO-PALCAR y 29 al modelo PCA. La edad media de los pacientes fue de 62 años (ds = 9,6). El tiempo medio de seguimiento postoperatorio ha sido 2 años (1,5-3). En la valoración clínica se ha utilizado el Test de Harris. La puntuación final total alcanzó 88,7 puntos (ds = 6,9) para el modelo PCA y 83,5 puntos (ds = 13,2) para el POROPALCAR. Los resultados clínicos fueron excelentes (80 a 100 puntos) en el 93 % de los implantes PCA y en el 67% PORO-PALCAR (p<0,01), con una remisión completa del dolor en más del 90% de los casos para ambos modelos. La mejoría funcional fue significativamente mayor para el modelo PCA. En cuanto a los resultados radiológicos, el modelo PORO-PALCAR presentó un hundimiento medio de 1,73 mm (p < 0,05). El 80% de los vástagos PCA y el 48% de los PORO-PALCAR no presentaban líneas radiolucientes en las zonas porosas (p<0,01). En las zonas inferiores, en más del 75% de los modelos PORO-PALCAR aparecieron líneas de hasta 2 mm de espesor y en el 21,2% líneas mayores de 2 mm en el vértice del vástago. Dos vástagos del modelo PORO-PALCAR presentaron signos de aflojamiento aséptico. Por lo tanto, el componente femoral del modelo PCA presentó una mejor fijación y osteointegración que el modelo PORO-PALCAR.The clinical and roentgenographic short-term results regarding femoral component of 62 non cemented total hip arthroplasties were evaluated. In 33 cases PORO-PALCAR model were implanted and in 29 cases PCA model were implanted. The average age of patients was 62 years (sd = 9,6). The average follow-up was 2 years, ranging from 1,5 to 3 years. Clinical assesment was performed using the Harris' score. The total end score reached 88,7 points (sd = 6,9) for the PCA model and 83,5 points (sd = 13,2) for the PORO-PALCAR model. Excellent clinical results (80 to 100 points) were found in 93 % of the patients with PCA model and in 67% of those with the PORO-PALCAR model (p<0,01). Pain was removed in more than 90% of the cases independently of the femoral model implanted. As for radiologic results, PORO-PALCAR model presented an average vertical subsidence of 1,73 mm (p<0,05). Radiolucent lines were not detected in 80% of PCA models and in 48% of PORO-PALCAR models around porous-surfaced (p < 0,01). In more of 75% of PORO-PALCAR models were observed radiolucent lines untill 2 mm of density in lower zones, and in 21% of cases radiolucent lines was greater than 2 mm around of stem apex. Two cases of PORO-PALCAR stem presented sings of aseptic loosening. Fixation and osteointegration seems to be better for the femoral component of PCA model than for the PORO-PALCAR stem