191 research outputs found
Experimental assessment and validation of an oil ferrous wear debris sensors family for wind turbine gearboxes
[EN] Purpose - The purpose of this study was to perform a complete experimental assessment of a family of oil ferrous wear debris sensor is performed.
The family comprised the original sensor and its re-engineered evolution, which is capable of detecting both amount and size of wear debris
particles trapped by the sensor and some predefined oil condition properties.
Design/methodology/approach ¿ In this work, the first step was to perform a design of experiments for the sensor validation. A specially defined
test rig was implemented, and different ferrous wear debris was collected. For each sensor, two different tests were performed. The first test was
called a ¿void test¿, where quantified amounts of debris were collided with the sensor without oil. The second one was a dynamic test, where the
sensor was installed in the test rig and different amounts of wear debris were added at a constant rate. In addition, specific tests related with oil
properties detection were studied.
Findings ¿ The results show excellent correlation of the sensor output signal with the amount of wear debris and a satisfactory detection of debris
size in all ranges. Also, the dynamic test presented adequate representativeness, and sensors performed well in this scenario.
Practical implications ¿ This paper shows the practical implementation of this type of sensor and the usual detection range and rate of detection
for different debris size and quantities.
Originality/value ¿ This work has a great utility for maintenance managers and equipment designers to fully understand the potential of this type
of sensor and its suitability for the application required.Authors would like to thank Iberdrola Generacion S.A. for their support in this project and Universitat Politecnica de Valencia for its support through contract FPI-S2-2015-1065 of Programa de Apoyo para la Investigacion y Desarrollo (PAID). Additionally, the authors would like to especially thank Daniel Veintimilla for their help in this work.Macian Martinez, V.; Tormos, B.; Miró Mezquita, G.; Rodes, I. (2018). Experimental assessment and validation of an oil ferrous wear debris sensors family for wind turbine gearboxes. Sensor Review. 38(1):84-91. https://doi.org/10.1108/SR-04-2017-0065S8491381Chiou, Y.-C., Lee, R.-T., & Tsai, C.-Y. (1998). An on-line Hall-effect device for monitoring wear particle in oils. Wear, 223(1-2), 44-49. doi:10.1016/s0043-1648(98)00289-0Du, L., & Zhe, J. (2011). A high throughput inductive pulse sensor for online oil debris monitoring. Tribology International, 44(2), 175-179. doi:10.1016/j.triboint.2010.10.022Holmberg, K., Adgar, A., Arnaiz, A., Jantunen, E., Mascolo, J., & Mekid, S. (Eds.). (2010). E-maintenance. doi:10.1007/978-1-84996-205-6Sheng, S. (2013), Report on Wind Turbine Subsystem Reliability - A Survey of Various Databases, NREL/PR-5000-59111
Current trends in ICE wear detection technologies: from lab to field
[EN] Research in internal combustion engine (ICE) tribology has been an active topic during the last decades, driven by different interest: first, in order to improve thermodynamics and overall engine performance, while nowadays there is an interest in reducing engine losses, including friction, in order to cut down fuel consumption and also exhaust emissions.
Tribology is a tri-vector science, where friction is the fundamental phenomena occurring between two surfaces, wear is the consequence of the occurrence of friction and lubrication is the solution for diminish friction and eliminate wear presence in the tribological system.
During the development of ICE, different technologies and techniques have been applied for detection of ICE wear, focused in different parts of the engine life and also used for different purposes, including research or maintenance.
In this work, a comprehensive look on this field is done, where several techniques are explained and their main application and pros and cons are highlighted.CMT-Motores Térmicos would like to thank the Spanish Ministerio de Ciencia e Innovación for its funding (Project no. TRA2015-70785-R) and Universitat Politècnica de València for its support through contract FPI-S2-2015-1065 of Programa de Apoyo para la Investigación y Desarrollo (PAID). The virtual vehicle research center acknowledges the financial support of the Austrian Science Fund (FWF): P27806-N30. Partial support was obtained from the "COMET - Competence Centers for Excellent Technologies Programme" of the Austrian Federal Ministry for Transport, Innovation and Technology (bmvit), the Austrian Federal Ministry of Science, Research and Economy (bmwfw), the Austrian Research Promotion Agency (FFG), the Province of Styria and the Styrian Business Promotion Agency (SFG).Miró Mezquita, G.; Tormos, B.; Allmaier, H.; Sander, D.; Knauder, C. (2017). Current trends in ICE wear detection technologies: from lab to field. ASRO Journal of Applied Mechanics. 2(1):32-41. http://hdl.handle.net/10251/151294S32412
Low viscosity engine oils: fuel economy and performance in a real-world fleet test.
[ES] Debido al fenómeno del calentamiento global, las emisiones de CO2 y la reducción del consumo de combustible en el transporte por carretera se han convertido en algunas de las preocupaciones más relevantes en el sector de la automoción. Todo este proceso ha hecho aparecer una variedad de soluciones técnicas de diferente complejidad tanto en costes de implementación como de mejora relativa. Dentro de todas ellas, una de las soluciones con una mejor relación coste-beneficio para reducir el consumo de combustible es el uso de aceites de baja viscosidad (LVO). Exsiten diferentes estudios con LVO en motores de combustión interna alternativos (MCIA), pero actualmente se dispone de datos limitados respecto al rendimiento en el uso de calle de estos. Este trabajo presenta un estudio en el que se evaluó el efecto de la utilización de LVO en una flota de autobuses urbanos en relación con el consumo de combustible y el rendimiento de aceite. Se realizó un análisis comparativo con 39 autobuses, mediante un amplio programa de control del consumo de combustible y análisis de aceite para evaluar los aspectos antes mencionados. Se evaluaron dos tecnologías de motores (Diésel / GNC) y 4 lubricantes diferentes, durante 2 intervalos de cambio de aceite, contabilizando más de 2 millones de kilómetros acumulados.
Los resultados han demostrado que estos aceites presentan beneficios en términos de ahorro de combustible, pero estrechamente vinculados al diseño del propio motor. Por otro lado, han presentado un excelente desempeño a lo largo del período de cambio de aceite, incluso mejorando algunas características de los aceites de referencia utilizados y sin penalización en términos de reducción del intervalo de cambio, indicador clave para los usuarios finales relacionados con los costes de mantenimiento.[EN] CO2 emissions and fuel consumption reduction in road transportation have become one of the most relevant concerns in automotive industry, led mainly by global warming. A variety of solutions has arisen to overcome this challenge, varying in technical complexity, implementation costs and terms. Among them, one proven cost-effective way to reduce fuel consumption is the use of low viscosity oils (LVO). There are different studies involving LVO and ICE, but currently limited data are available regarding "real-world" performance of LVO. This paper presents a study where the effect of the use of LVO on urban buses regarding fuel consumption and oil performance is assessed. A comparative analysis using 39 buses was performed, based on an extensive fuel consumption control and oil analysis program to assess aspects aforementioned. 2 engine technologies (Diesel / CNG) were considered and 4 different lubricants. Test duration comprised 2 oil drain intervals, totalizing more than 2 million of km accumulated. The results have shown that LVO have benefits in terms of fuel economy, closely linked to the engine design. On the other hand, they presented an excellent performance during oil drain interval, even improving some characteristics of the reference oils used, without penalty in terms of reducing the oil lifespan, a key indicator for end users related maintenance costs.Los autores desean agradecer al Ministerio de Ciencia e Innovación por su financiación en este proyecto (Proyecto TRA2012-30907), y la EMT de València por su colaboración.Tormos, B.; Miró Mezquita, G.; Perez-Gutierrez, T.; De-Diego-Pardo, J. (2016). Aceites de motor de baja viscosidad: ahorro de combustible y ensayos en condiciones reales. DYNA: Ingeniería e Industria. 91(6):668-674. https://doi.org/10.6036/7974S66867491
Genome-wide analyses for personality traits identify six genomic loci and show correlations with psychiatric disorders
Personality is influenced by genetic and environmental factors1
and associated with mental health. However, the underlying
genetic determinants are largely unknown. We identified six
genetic loci, including five novel loci2,3, significantly associated
with personality traits in a meta-analysis of genome-wide
association studies (N = 123,132–260,861). Of these genomewide
significant loci, extraversion was associated with variants
in WSCD2 and near PCDH15, and neuroticism with variants
on chromosome 8p23.1 and in L3MBTL2. We performed a
principal component analysis to extract major dimensions
underlying genetic variations among five personality traits
and six psychiatric disorders (N = 5,422–18,759). The first
genetic dimension separated personality traits and psychiatric
disorders, except that neuroticism and openness to experience
were clustered with the disorders. High genetic correlations
were found between extraversion and attention-deficit–
hyperactivity disorder (ADHD) and between openness and
schizophrenia and bipolar disorder. The second genetic
dimension was closely aligned with extraversion–introversion
and grouped neuroticism with internalizing psychopathology
(e.g., depression or anxiety)
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derived neutrophil to lymphocyte ratio dnlr change between baseline and cycle 2 is correlated with benefit during immune checkpoint inhibitors ici in advanced non small cell lung cancer nsclc patients
n/
Impact of intercurrent introduction of steroids on clinical outcomes in advanced non-small-cell lung cancer (Nsclc) patients under immune-checkpoint inhibitors (ici)
Background: Baseline steroids before ICI have been associated with poor outcomes, particularly when introduced due to cancer symptoms. Methods: Retrospective analysis of advanced NSCLC patients treated with ICI. We collected the use of intercurrent steroids (≥10 mg of prednisone-equivalent) within the first eight weeks of ICI. We correlated steroid use with patient outcomes according to the indications. Results: 413 patients received ICI, 299 were steroids-naïve at baseline. A total of 49 patients received intercurrent steroids (16%), of whom 38 for cancer-related symptoms and 11 for other indications, such as immune-related events. Overall, median (m) progression-free survival (PFS) was 1.9 months (mo.) [95% CI, 1.8-2.4] and overall survival (OS) 10 mo. [95% CI, 8.1–12.9]. Intercurrent steroids under ICI correlated with a shorter PFS/OS (1.3 and 2.3 mo. respectively, both p < 0.0001). Intercurrent steroids for cancer-related symptoms correlated with poorest mPFS [1.1 mo.; 95% CI, 0.9–1.5] and mOS [1.9 mo.; 95%CI, 1.5–2.4; p < 0.0001)]. No mOS and mPFS differences were found between cancer-unrelated-steroid group and no-steroid group. Steroid use for cancer-related symptoms was an independent prognostic factor for poor PFS [HR 2.64; 95% CI, 1.2–5.6] and OS [HR 4.53; 95% CI, 1.8–11.1], both p < 0.0001. Conclusion: Intercurrent steroids during ICI had no detrimental prognostic impact if the indication was unrelated to cancer symptoms
Serum osteoprotegerin level, carotid-femoral pulse wave velocity and cardiovascular survival in haemodialysis patients
BACKGROUND: Osteoprotegerin (OPG) is a marker and regulator of
arterial calcification, and it is related to cardiovascular
survival in haemodialysis patients. The link between OPG and
aortic stiffening--a consequence of arterial calcification--has
not been previously evaluated in this population, and it is not
known whether OPG-related mortality risk is mediated by arterial
stiffening. METHODS: At baseline, OPG and aortic pulse wave
velocity (PWV) were measured in 98 chronic haemodialysis
patients who were followed for a median of 24 months. The
relationship between OPG and PWV was assessed by multivariate
linear regression. The role of PWV in mediating OPG related
cardiovascular mortality was evaluated by including both OPG and
PWV in the same survival model. RESULTS: At baseline mean
(standard deviation) PWV was 11.2 (3.3) m/s and median OPG
(interquartile range) was 11.1 (7.5-15.9) pmol/L. There was a
strong, positive, linear relationship between PWV and lnOPG (P =
0.009, model R(2) = 0.540) independent of covariates. During
follow-up 23 patients died of cardiovascular causes. In separate
univariate survival models both PWV and lnOPG were related to
cardiovascular mortality [hazard ratios 1.31 (1.14-1.50) and
8.96 (3.07-26.16), respectively]. When both PWV and lnOPG were
entered into the same model, only lnOPG remained significantly
associated with cardiovascular mortality [hazard ratio 1.11
(0.93-1.33) and 7.18 (1.89-27.25), respectively). CONCLUSION: In
haemodialysis patients OPG is strongly related to PWV and OPG
related cardiovascular mortality risk is, in part, mediated by
increased PWV
"Single nucleotide polymorphisms of the OPG/RANKL system genes in primary hyperparathyroidism and their relationship with bone mineral density"
<p>Abstract</p> <p>Background</p> <p>Primary hyperparathyroidism (PHPT) affects mainly cortical bone. It is thought that parathyroid hormone (PTH) indirectly regulates the activity of osteoclasts by means of the osteoprotegerin/ligand of the receptor activator of nuclear factor-κβ (OPG/RANKL) system. Several studies have confirmed that <it>OPG </it>(osteoprotegerin) and <it>RANKL </it>(ligand of the receptor activator of nuclear factor-κβ) loci are determinants of bone mineral density (BMD) in the general population. The aim of this study is to analyze the relationship between fractures and BMD and the rs3102735 (163 A/G), rs3134070 (245 T/G) and rs2073618 (1181 G/C) SNPs of the <it>OPG </it>and the rs2277438 SNP of the <it>RANKL</it>, in patients with sporadic PHPT.</p> <p>Methods</p> <p>We enrolled 298 Caucasian patients with PHPT and 328 healthy volunteers in a cross-sectional study. We analyzed anthropometric data, history of fractures or renal lithiasis, biochemical determinants including markers for bone remodelling, BMD measurements in the lumbar spine, total hip, femoral neck and distal radius, and genotyping for the SNPs to be studied.</p> <p>Results</p> <p>Regarding the age of diagnosis, BMI, menopause status, frequency of fractures or renal lithiasis, we found no differences between genotypes in any of the SNPs studied in the PHPT group. Significant lower BMD in the distal radius with similar PTH levels was found in the minor allele homozygotes (GG) compared to heterozygotes and major allele homozygotes in both <it>OPG </it>rs3102735 (163 A/G) and <it>OPG </it>rs3134070 (245 T/G) SNPs in those with PHPT compared to control subjects. We found no differences between genotypes of the <it>OPG </it>rs2073618 (1181 G/C) SNP with regard to BMD in the PHPT subjects. In the evaluation of rs2277438 SNP of the <it>RANKL </it>in PHPT patients, we found a non significant trend towards lower BMD in the 1/3 distal radius and at total hip in the minor allele homocygotes (GG) genotype group versus heterocygotes and major allele homocygotes (AA).</p> <p>Conclusions</p> <p>Our study provides the first evaluation of the relationship between SNPs of the <it>OPG/RANK </it>system and sporadic PHPT. Subjects with PHPT and minor homocygote genotype (GG) for the <it>OPG </it>rs3102735 (163 A/G) and <it>OPG </it>rs3134070 (245 T/G) SNPs have lower BMD in the distal radius, and this association does not appear to be mediated by differences in PTH serum levels.</p
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