Effect of in-cylinder swirl on engine efficiency and heat rejection in a light-duty diesel engine

[EN] During the last years, the growing awareness about the impacts of climate change lead to an increase in the importance of the efficiency over other criteria in the design of internal combustion engines. In this framework, the heat transfer to the combustion chamber walls can be considered as one of the main sources of indicated efficiency diminution. Hence, the main objective of this research is to thoroughly assess the effect of the swirl ratio on the heat rejection to the chamber walls, and thus on the efficiency, of a fully instrumented four-cylinder direct-injection diesel engine with variable swirl ratio (covering the range from 1.4 to 3). The analysis, based on the engine global energy balance, includes a combination of theoretical and experimental tools such as thermal flow measurement and dedicated thermocouples in the cylinder head and liner. Considering the results, it is shown that an increase in swirl ratio leads to a heat transfer enhancement, along with important changes on the combustion development. As a result of the combination of these two effects, it is shown that intermediate swirl ratios can slightly improve engine efficiency at low load, while increasing swirl worsens the combustion process and efficiency at high load. However, convective heat transfer increases about 3% of the fuel energy in the chamber when swirl ratio increases from 1.4 to 3. The heat rejection characterization is completed with the analysis of the wall temperatures. Despite the observed trends, heat transfer does not seem to be the only key issue for explaining the indicated and brake efficiencies, thus the pumping work plays an important role due to the effect of reducing the intake section to generate the swirl motion.This work was supported by GM Global R&D and the Spanish Ministry of Economy and Competitiveness (TRA2013-41348-R).Olmeda, P.; Martín, J.; Blanco-Cavero, D.; Warey, A.; Domenech, V. (2017). Effect of in-cylinder swirl on engine efficiency and heat rejection in a light-duty diesel engine. International Journal of Engine Research. 18(1-2):81-92. https://doi.org/10.1177/1468087417693078S8192181-

On the sub-micron aerosol size distribution in a coastal-rural site at El Arenosillo Station (SW – Spain)

This study focuses on the analysis of the sub-micron aerosol characteristics at El Arenosillo Station, a rural and coastal environment in South-western Spain between 1 August 2004 and 31 July 2006 (594 days). The mean total concentration (<i>N</i><sub>T</sub>) was 8660 cm<sup>−3</sup> and the mean concentrations in the nucleation (<i>N</i><sub>NUC</sub>), Aitken (<i>N</i><sub>AIT</sub>) and accumulation (<i>N</i><sub>ACC</sub>) particle size ranges were 2830 cm<sup>−3</sup>, 4110 cm<sup>−3</sup> and 1720 cm<sup>−3</sup>, respectively. Median size distribution was characterised by a single-modal fit, with a geometric diameter, median number concentration and geometric standard deviation of 60 nm, 5390 cm<sup>−3</sup> and 2.31, respectively. Characterisation of primary emissions, secondary particle formation, changes to meteorology and long-term transport has been necessary to understand the seasonal and annual variability of the total and modal particle concentration. Number concentrations exhibited a diurnal pattern with maximum concentrations around noon. This was governed by the concentrations of the nucleation and Aitken modes during the warm seasons and only by the nucleation mode during the cold seasons. Similar monthly mean total concentrations were observed throughout the year due to a clear inverse variation between the monthly mean <i>N</i><sub>NUC</sub> and <i>N</i><sub>ACC</sub>. It was related to the impact of desert dust and continental air masses on the monthly mean particle levels. These air masses were associated with high values of <i>N</i><sub>ACC</sub> which suppressed the new particle formation (decreasing <i>N</i><sub>NUC</sub>). Each day was classified according to a land breeze flow or a synoptic pattern influence. The median size distribution for desert dust and continental aerosol was dominated by the Aitken and accumulation modes, and marine air masses were dominated by the nucleation and Aitken modes. Particles moved offshore due to the land breeze and had an impact on the particle burden at noon, especially when the wind was blowing from the NW sector in the morning during summer time. This increased <i>N</i><sub>NUC</sub> and <i>N</i><sub>AIT</sub> by factors of 3.1 and 2.4, respectively. Nucleation events with the typical "banana" shape were characterised by a mean particle nucleation rate of 0.74 cm<sup>−3</sup> s<sup>−1</sup>, a mean growth rate of 1.96 nm h<sup>−1</sup> and a mean total duration of 9.25 h (starting at 10:55 GMT and ending at 20:10 GMT). They were observed for 48 days. Other nucleation events were identified as those produced by the emissions from the industrial areas located at a distance of 35 km. They were observed for 42 days. Both nucleation events were strongly linked to the marine air mass origin

Distribución temporal del tamaño de los molariformes de Ursus spelaeus Ros.-Hein.ibérico

[Abstract] This paper deals with a metrical comparison of cheek-teeth length of Ursus spelaeus Ros.-Hein.Iberian population representatives

The Spanish Network on Environmental DMAs: introduction and main activities

Comunicación presentada en: V Reunión Española de Ciencia y Tecnología de Aerosoles – RECTA 2011 celebrada del 27 al 29 de junio de 2011 en CIEMAT, Madrid

The FXII c.-4T > C Polymorphism as a Disease Modifier in Patients With Hereditary Angioedema Due to the FXII p.Thr328Lys Variant

Background: Hereditary angioedema due to the Thr328Lys variant in the coagulation factor XII (HAE-FXII) affects mainly women in whom the symptomatology is dependent on high estrogen levels. Clinical variability and incomplete penetrance are challenging features that hinder the diagnosis and management of HAE-FXII. The c.-4T>C Kozak polymorphism is the only common variation accounting for FXII plasma levels and was previously shown to modify the course of HAE due to C1-Inhibitor deficiency. Objectives: To assess the influence of the c.-4T>C polymorphism on disease expression in 39 Spanish HAE-FXII index patients. Methods: The c.-4T>C polymorphism was sequenced by the standard Sanger method, and HAE severity was calculated according to the score by Cumming et al. (2003) The activation of the contact system was quantified by the kallikrein-like activity of plasma in chromogenic assays upon activation with high-molecular-weight dextran sulfate. Results: The c.-4CC genotype was overrepresented in the studied cohort: 82% were CC-homozygous (expected frequency = 59%) and 18% were CT-heterozygous (expected frequency = 39%) (p = 0.001). Patients with a c.-4CC genotype exhibited higher kallikrein-like activity (0.9659 +/- 0.1136) than those with a c.-4TC genotype (0.7645 +/- 0.1235) (p = 0.024) or healthy donors. Moreover, the polymorphism influenced HAE-FXII severity score (c.-4CC = 4.43 +/- 2.28 vs c.-4TC = 2.0 +/- 1.15; p = 0.006) but not the degree of estrogen dependence or time until remission. Conclusion: The c.-4T>C polymorphism is overrepresented in a Spanish HAE-FXII cohort and significantly influences the degree of contact system activation and the clinical severity of the disease

Defects of splicing in antithrombin deficiency

Background: There is increasing evidence supporting the relevance of aberrant splicing in multiple disorders. In antithrombin deficiency only 22 intronic mutations affecting splicing sites (7% of SERPINC1 mutations) are considered as splicing mutations. Methods: SERPINC1 was analyzed by Sanger sequencing and MLPA in 141 unrelated cases with antithrombin deficiency. Plasma antithrombin was studied by functional and western blot assays, purified by FPLC and characterized by proteomic analysis. In silico predictions on splicing was done with the Human Splicing Finder software. Results: We detected 89 different SERPINC1 defects, 13 with potential effect on splicing. Ten cases presented 9 mutations disturbing splicing sites, 5 new. Three gross or small gene defects also disturbed a correct splicing. Interestingly, the first duplication of a single exon ever described (c.1154-13_1218+115dup), caused mild deficiency (75%). A deeper intronic mutation (c.1154-14G>A), identified in three unrelated patients with traces of disulphide dimers of antithrombin in plasma, created a cryptic splicing site that might generate a variant with 4 additional in frame residues according to in silico predictions. This aberrant splicing was confirmed by proteomic analysis of the dimer purified from plasma. Conclusions: A high proportion of cases with antithrombin deficiency (up to 13%) may be explained by an aberrant splicing. Up to 15% of mutations in SERPINC1: splicing site variations, gross gene defects and deep intronic mutations, may affect a correct splicing with three potential consequences type I, type II, and even moderate antithrombin deficiency

Detection of an optical transient following the 13 March 2000 short/hard gamma-ray burst

We imaged the error box of a gamma-ray burst of the short (0.5 s), hard type (GRB 000313), with the BOOTES-1 experiment in southern Spain, starting 4 min after the gamma-ray event, in the I-band. A bright optical transient (OT 000313) with I = 9.4 +/- 0.1 was found in the BOOTES-1 image, close to the error box (3-sigma) provided by BATSE. Late time VRIK'-band deep observations failed to reveal an underlying host galaxy. If the OT 000313 is related to the short, hard GRB 000313, this would be the first optical counterpart ever found for this kind of events (all counterparts to date have been found for bursts of the long, soft type). The fact that only prompt optical emission has been detected (but no afterglow emission at all, as supported by theoretical models) might explain why no optical counterparts have ever been found for short, hard GRBs.This fact suggests that most short bursts might occur in a low-density medium and favours the models that relate them to binary mergers in very low-density enviroments.Comment: Revised version. Accepted for publication in Astronomy and Astrophysics Letters, 5 pages, 3 figure

Afecciones quirúrgicas en el recién nacido. Nuestras estadísticas. 2002-2003. Surgical conditions in the new-born. Our statistics-2002-2003

Las afecciones quirúrgicas en el neonato tienen una alta morbimortalidad, por la condición de recién nacido, los trastornos ocasionados por la enfermedad de base así como por la injuria provocada posteriormente por la intervención quirúrgica. Se realizó un estudio retrospectivo por la intervención quirúrgica. Se realizó un estudio retrospectivo, longitudinal de todos los neonatos a los cuales se le diagnosticó patologías quirúrgicas en el periodo comprendido entre enero de 2002 hasta diciembre de 2003 en la provincia de Pinar del Río (Cuba) con el objetivo de analizar el comportamiento diagnóstico y terapéutico de estos pacientes. En esta etapa se intervinieron quirúrgicamente 24 recién nacidos, la mayoría fueron masculinos (17), la operación se realizó con menos de 24 horas de nacido en 14 casos, las afecciones quirúrgicas más frecuentes fueron las de intestino delgado con 7 pacientes y la supervivencia fue de un 100 %, logrando la mejor tasa de supervivencia de los últimos años en este territorio. DeCS: CIRUGIA/patología/diagnóstico, MORBILIDAD, MORTALIDAD, NEONATOLOGÍA. ABSTRACT Surgical diseases in neonates have a high morbidity because of the condition of being newborn, disorder caused by the underlying disease as well as the injury caused further by surgery. A retrospective, longitudinal study was carried out with all the neonates who where diagnosed to have surgical pathologies from January 2002 to December 2003 in Pinar del Río province, Cuba, aimed at analyzing diagnostic and therapeutic behaviour of these patients. During this period, 24 newborns underwent surgery; most of them were males (17). The surgery was performed in a period of 24 hours after being born in 14 cases, the most frequent surgical diseases were associated with the tenue intestinum in 7 patients and survival was 100 %, achieving the best survival rate during the last few years in the province. DeCS: SURGERY/pathology/diagnosis, MORBIDITY, MORTALITY, NEONATOLOGY

Afecciones quirúrgicas en el recién nacido. Nuestras estadísticas. 2002-2003. Surgical conditions in the new-born. Our statistics-2002-2003

Las afecciones quirúrgicas en el neonato tienen una alta morbimortalidad, por la condición de recién nacido, los trastornos ocasionados por la enfermedad de base así como por la injuria provocada posteriormente por la intervención quirúrgica. Se realizó un estudio retrospectivo por la intervención quirúrgica. Se realizó un estudio retrospectivo, longitudinal de todos los neonatos a los cuales se le diagnosticó patologías quirúrgicas en el periodo comprendido entre enero de 2002 hasta diciembre de 2003 en la provincia de Pinar del Río (Cuba) con el objetivo de analizar el comportamiento diagnóstico y terapéutico de estos pacientes. En esta etapa se intervinieron quirúrgicamente 24 recién nacidos, la mayoría fueron masculinos (17), la operación se realizó con menos de 24 horas de nacido en 14 casos, las afecciones quirúrgicas más frecuentes fueron las de intestino delgado con 7 pacientes y la supervivencia fue de un 100 %, logrando la mejor tasa de supervivencia de los últimos años en este territorio. DeCS: CIRUGIA/patología/diagnóstico, MORBILIDAD, MORTALIDAD, NEONATOLOGÍA. ABSTRACT Surgical diseases in neonates have a high morbidity because of the condition of being newborn, disorder caused by the underlying disease as well as the injury caused further by surgery. A retrospective, longitudinal study was carried out with all the neonates who where diagnosed to have surgical pathologies from January 2002 to December 2003 in Pinar del Río province, Cuba, aimed at analyzing diagnostic and therapeutic behaviour of these patients. During this period, 24 newborns underwent surgery; most of them were males (17). The surgery was performed in a period of 24 hours after being born in 14 cases, the most frequent surgical diseases were associated with the tenue intestinum in 7 patients and survival was 100 %, achieving the best survival rate during the last few years in the province. DeCS: SURGERY/pathology/diagnosis, MORBIDITY, MORTALITY, NEONATOLOGY

Calibration and intercomparison results in the Spanish network on environmental DMAs

Comunicación presentada en: 2012 European Aerosol Conference (EAC-2012), B-WG01S2P30, celebrada del 2 al 7 de septiembre de 2012 en Granada.This network is financed by the Ministry of Science and Innovation (CGL2011-15008-E)