8 research outputs found
Implementation of the Partially Premixed Combustion concept in a 2-stroke HSDI diesel engine fueled with gasoline
Partially Premixed Combustion (PPC) of fuels in the gasoline octane range has proven to combine low NOX and soot emissions with high indicated efficiencies, while still retaining control over combustion phasing with the injection event. Previous research performed in four-stroke engines, has shown how the operating region where gasoline PPC concept can be successfully implemented is largely linked to the octane number of the fuel, making difficult to cover the entire load range with a fixed fuel.
In this framework, 2-stroke engines arise as a promising solution to extend the load range of gasoline PPC concept, since it intrinsically provides equivalent torque response with only half the IMEP required in a 4-stroke cycle. Moreover, 2-stroke architecture provides high flexibility on the air management parameters to substantially control the cylinder conditions and affect the combustion environment, allowing proper combustion control even in low load conditions.
An experimental investigation has been performed to evaluate the potential of the PPC concept for pollutant control, using a commercial gasoline with Research Octane Number of 95 in a newly-designed 2-stroke poppet valves automotive diesel engine. The experimental results confirm how it is possible to achieve stable gasoline PPC combustion at a low speed medium load point (1200 rpm, 5 bar IMEP); with good combustion stability (σIMEP below 3%), high combustion efficiency (over 98%), and low NOX and zero soot levels; thanks to the wide control of the cylinder gas temperature provided by the air management settings. Nevertheless, in agreement to the results reported in the literature, the indicated cycle efficiency attained at this low load operating condition is lower than the obtained in conventional diesel combustion conditions. Therefore, a dedicated optimization process of the engine hardware and engine settings is required to fully exploit the benefits of gasoline PPC concept in the investigated 2-stroke engine architecture.The authors of this paper thank the Spanish Ministry of Economy and Competitiveness for the financial support of this research through the Project TRA 2010-20271 (LOWTECOM).Benajes Calvo, JV.; Molina Alcaide, SA.; Novella Rosa, R.; De Lima Moradell, DA. (2014). Implementation of the Partially Premixed Combustion concept in a 2-stroke HSDI diesel engine fueled with gasoline. Applied Energy. 122:94-111. https://doi.org/10.1016/j.apenergy.2014.02.013S9411112
Teaching Methodologies for Combustion Science within the European Higher Education Area
[EN] The main objective of the present work is the selection and integration of different methodologies among those applicable within the framework of the European Higher Education Area to combine teaching methods with high implication from both lecturers and students. The aim is to enhance the students’ motivation, by means of which they should learn both combustion fundamentals as well as particular technological applications. Thus, the selected methods are master classes, guided work by means of learning based upon projects, simulations and numerical applications, tutoring and student independent work. This methodology is currently been applied within the Mechanical Engineer Degree of the Escuela Técnica Superior de Ingeniería del Diseño at the Universitat Politècnica de València. Results have been critically analyzed, paying attention to both the performance of the students as well as to some inconsistencies that have been found when applying the developed methodologies to large groups. The main result to be noted is the high comprehension level of the course concepts that has been attained by the students.Molina Alcaide, SA.; López, JJ.; García Oliver, JM.; García Martínez, A. (2014). Teaching Methodologies for Combustion Science within the European Higher Education Area. Multidisciplinary Journal for Education, Social and Technological Sciences. 1(1):1-16. doi:10.4995/muse.2014.2190SWORD11611Abercrombie M.L.J (1980). Aims and techniques of Group teaching. London, Society of Research in Higher Education.Anderson C. (1997). Enabling and shaping understanding through tutorials, En F. Marton et al., The Experience of Learning. Edinburg: Scottish University Press.Biggs J. and Tang C. (2011). Teaching for quality learning at university. McGraw – Hill Education, Open University Press.Collier G., (1983) The Management of Peer-group Learning: Syndicate Methods in Higher Education. Guildford: Society for Research into Higher Education.Desantes J.M., García-Oliver J.M., Novella R. and García A. (2009). Methodology of continous teaching-learning applied to combustión science. XVII Conference on Educational Innovation in Technical Sciences, Valencia.Turns S. R. (2000). An introduction to combustion: Concepts and applications. United States, McGraw-Hill Science
Effectiveness of an intervention for improving drug prescription in primary care patients with multimorbidity and polypharmacy:Study protocol of a cluster randomized clinical trial (Multi-PAP project)
This study was funded by the Fondo de Investigaciones Sanitarias ISCIII (Grant Numbers PI15/00276, PI15/00572, PI15/00996), REDISSEC (Project Numbers RD12/0001/0012, RD16/0001/0005), and the European Regional Development Fund ("A way to build Europe").Background: Multimorbidity is associated with negative effects both on people's health and on healthcare systems. A key problem linked to multimorbidity is polypharmacy, which in turn is associated with increased risk of partly preventable adverse effects, including mortality. The Ariadne principles describe a model of care based on a thorough assessment of diseases, treatments (and potential interactions), clinical status, context and preferences of patients with multimorbidity, with the aim of prioritizing and sharing realistic treatment goals that guide an individualized management. The aim of this study is to evaluate the effectiveness of a complex intervention that implements the Ariadne principles in a population of young-old patients with multimorbidity and polypharmacy. The intervention seeks to improve the appropriateness of prescribing in primary care (PC), as measured by the medication appropriateness index (MAI) score at 6 and 12months, as compared with usual care. Methods/Design: Design:pragmatic cluster randomized clinical trial. Unit of randomization: family physician (FP). Unit of analysis: patient. Scope: PC health centres in three autonomous communities: Aragon, Madrid, and Andalusia (Spain). Population: patients aged 65-74years with multimorbidity (≥3 chronic diseases) and polypharmacy (≥5 drugs prescribed in ≥3months). Sample size: n=400 (200 per study arm). Intervention: complex intervention based on the implementation of the Ariadne principles with two components: (1) FP training and (2) FP-patient interview. Outcomes: MAI score, health services use, quality of life (Euroqol 5D-5L), pharmacotherapy and adherence to treatment (Morisky-Green, Haynes-Sackett), and clinical and socio-demographic variables. Statistical analysis: primary outcome is the difference in MAI score between T0 and T1 and corresponding 95% confidence interval. Adjustment for confounding factors will be performed by multilevel analysis. All analyses will be carried out in accordance with the intention-to-treat principle. Discussion: It is essential to provide evidence concerning interventions on PC patients with polypharmacy and multimorbidity, conducted in the context of routine clinical practice, and involving young-old patients with significant potential for preventing negative health outcomes. Trial registration: Clinicaltrials.gov, NCT02866799Publisher PDFPeer reviewe
TRANSFERENCIA DE MASA Y ENERGÍA: EJERCICIOS RESUELTOS
Este libro presenta una relación de ejercicios que tienen como objetivo la aplicación de nociones fundamentales en trasferencia de masa y energía. A través de su desarrollo, el lector podrá comprobar los conocimientos adquiridos en esta materia y consolidarlos mediante la exposición clara y precisa de la resolución de problemas. Va dirigido fundamentalmente a estudiantes que se estén formando en el campo de la Ingeniería Aeroespacial, y cuenta con la profesionalidad y experiencia en el ámbito académico de sus autores.Desantes Fernández, JM.; Molina Alcaide, SA.; Salvador Rubio, FJ.; Fajardo Peña, P. (2014). TRANSFERENCIA DE MASA Y ENERGÍA: EJERCICIOS RESUELTOS. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/67107EDITORIA
Cuestiones y problemas resueltos de Ingeniería Térmica
Este libro recoge una colección de ejercicios resueltos de Ingeniería Térmica distribuídos en cinco capítulos en los que se tratan diferentes aspectos de la transmisión de calor. Se abordan los mecanismos básicos como la transmisión de calor por conducción, por convección y por radiación, así como los fundamentos de intercambiadores de calor y máquinas térmicas de ciclo inverso, dispositivos éstos diseñados para transferir calor entre fluidos.
El libro pretende dotar a la comunidad universitaria de material de apoyo para la adquisición de destrezas en la resolución de ejercicios prácticos de Ingeniería Térmica. El conjunto resulta una colección de cuestiones homogénea y completa, adecuada para reforzar, a través de ejercicios prácticos,los conceptos adquiridos por alumnos de Ingeniería con especialidades afines a la materia.Bracho León, GC.; Arnau Martínez, FJ.; Molina Alcaide, SA.; Dolz Ruiz, V. (2023). Cuestiones y problemas resueltos de Ingeniería Térmica. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/19273
Ruminal metagenomic libraries as a source of relevant hemicellulolytic enzymes for biofuel production
The success of second-generation (2G) ethanol technology
relies on the efficient transformation of hemicellulose
into monosaccharides and, particularly, on
the full conversion of xylans into xylose for over
18% of fermentable sugars. We sought new hemicellulases
using ruminal liquid, after enrichment of
microbes with industrial lignocellulosic substrates
and preparation of metagenomic libraries. Among
150 000 fosmid clones tested, we identified 22
clones with endoxylanase activity and 125 with bxylosidase
activity. These positive clones were
sequenced en masse, and the analysis revealed
open reading frames with a low degree of similarity
with known glycosyl hydrolases families. Among
them, we searched for enzymes that were thermostable
(activity at > 50°C) and that operate at high
rate at pH around 5. Upon a wide series of assays,
the clones exhibiting the highest endoxylanase and b-xylosidase activities were identified. The fosmids
were sequenced, and the corresponding genes
cloned, expressed and proteins purified. We found
that the activity of the most active b-xylosidase was
at least 10-fold higher than that in commercial enzymatic
fungal cocktails. Endoxylanase activity was in
the range of fungal enzymes. Fungal enzymatic
cocktails supplemented with the bacterial hemicellulases
exhibited enhanced release of sugars from pretreated
sugar cane straw, a relevant agricultural
residue
Interplay between psychosocial and heart failure related factors may partially explain limitations in self-efficacy in patients with heart failure and poor self-care behaviour: insights from a real-world cohort of 1,123 patients
Background and aims: Worse self-care is associated with a higher risk of readmission and mortality in patients with heart failure (HF). Little is known about how the interplay between clinical and psycho-social factors may modulate self-care behaviours in these patients. The aim of our study was to identify clinical, and particularly psycho-social factors associated with worse self-care and assess their interaction inpatients with heart failure. Methods and results: We conducted an observational, prospective, cohort study of 1,123 consecutive patients with chronic heart failure.. Self-care was assessed with the modified European Heart Failure Self-care Behavior Scale 9-item version (EHFSCBS-9), and both clinical and psycho-social profile of the patients included were also meticulously evaluated. A total of 484 patients (43%) were women, mean age was 72 years, and mean left ventricular ejection fraction was 44.5%. In multivariable analyses combining clinical and psycho-social factors, low social support (OR 3.53, 95% CI [2.13-5.86]; p-value <0.001), absence of caregiver support (OR 2.16, 95% CI [1.34 -3.48]; p-value 0.001) and depressive symptoms (OR 2.40, 95% CI [1.53-3.77]; p-value <0.001) were independent determinants of impaired global self-care. Advanced functional class was associated with better self-care (OR 0.43, 95%CI [0.26-0.70]; p-value 0.001). No other clinical factors remained significantly associated with self-care in these joint models. In discrimination analyses, models containing psycho-social determinants outperformed models only containing heart failure -related (clinical) variables (all p-values<0.001). Conclusion: Impairment in self-care behaviour is strongly determined by psycho-social factors. Specifically, low social support, the lack of caregiver support and the presence of depressive symptoms are the main drivers of the risk of impairment of self-care in heart failure patients. Evaluation of self-care and self-care interventions should be complemented by a comprehensive psycho-social assessment in patients with heart failure
Revolution: Museo de las estrellas un paseo por la fama : Hollywood
Convocatoria proyectos de innovación de Extremadura 2020/2021Se describe un proyecto llevado a cabo entre 13 centros educativos extremeños que consistió en desarrollar cinco unidades de trabajo gamificadas, cinco historias detectivescas con misterios por resolver, donde se ponían a prueba las habilidades de lógica, la capacidad de observación, de concentración y de atención de los alumnos. Los objetivos principales de la propuesta fueron: promover la puesta en práctica de proyectos intercentros; impulsar pedagogías activas; desarrollar la competencia digital a través del uso de las pedagogías emergentes lo que ha permitido llevar a cabo una enseñanza presencial, híbrida y virtual y atender a la diversidadExtremaduraES