1,699 research outputs found
Estimation of the in-cylinder residual mass fraction at Intake Valve Closing in a 2-stroke High-Speed Direct-Injection Compression-Ignition engine
This is the author's version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting,
and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087418813406.[EN] New combustion concepts and engine designs are being currently investigated in order to comply with upcoming pollutant regulations and reduce fuel consumption. In this context, two-stroke architectures appear as a promising solution for the implementation of some combustion concepts. However, scavenging processes in a two-stroke engine are much more challenging than for a four-stroke engine, and the residual mass of burnt gases retained inside the cylinder needs to be properly determined in order to keep control over the in-cylinder composition, hence over the combustion conditions and pollutant emissions. In this study, a new methodology for the estimation of the internal residual gas fraction is introduced, which is based on the thermodynamic processes occurring in the engine investigated and makes use of basic engine instrumentation and measurement equipment usually available in a conventional test cell. Several versions of the estimator were developed so that different requirements could be met, such as those of real-time estimation on an engine test bench but with reduced precision or, on the contrary, highly precise but time-consuming computations for post-processing purposes and combustion diagnosis. The consistency of the internal residual gas estimator was then validated through its application to real engine tests at different operating points.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research has been sponsored by the European Union in framework of the REWARD project, Horizon 2020 research and innovation program under grant agreement no. 636380. The authors kindly recognize the technical support provided by Mr Gilles Coma and his research group at RENAULT SAS, and also by the research group at IFPEN, along the development of the investigations presented here.Torregrosa, AJ.; Martín, J.; Novella Rosa, R.; Thein, K. (2020). Estimation of the in-cylinder residual mass fraction at Intake Valve Closing in a 2-stroke High-Speed Direct-Injection Compression-Ignition engine. International Journal of Engine Research. 21(5):838-855. https://doi.org/10.1177/1468087418813406S838855215Galindo, J., Luján, J. M., Serrano, J. R., & Hernández, L. (2005). Combustion simulation of turbocharger HSDI Diesel engines during transient operation using neural networks. Applied Thermal Engineering, 25(5-6), 877-898. doi:10.1016/j.applthermaleng.2004.08.004Payri, F., Benajes, J., Galindo, J., & Serrano, J. R. (2002). Modelling of turbocharged diesel engines in transient operation. Part 2: Wave action models for calculating the transient operation in a high speed direct injection engine. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 216(6), 479-493. doi:10.1243/09544070260137507Rakopoulos, C. ., Rakopoulos, D. ., Giakoumis, E. ., & Kyritsis, D. . (2004). Validation and sensitivity analysis of a two zone Diesel engine model for combustion and emissions prediction. 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Post Operative Fungal Endopthalmitis Due to \u3cem\u3eGeotrichum candidum\u3c/em\u3e
Geotrichum species have been rarely reported as the cause of sepsis, disseminated infection in immunosuppressed patients. The patient we describe developed indolent endophthalmitis four months after her routine right eye cataract surgery. The intraoperative sample from right vitreous fluid grew Geotrichum candidum. The patient underwent vitrectomy, artificial lens explantation and intravitreal injection of amphotericin B followed by oral voriconazole. Despite these interventions, she underwent enucleation. This is the first published case of Geotrichum candidum endophthalmitis
Simple guide to starting a research group
Conducting cutting-edge research and scholarship becomes more complicated with each passing year; forming a collaborative research group offers a way to navigate this increasing complexity. Yet many individuals whose work might benefit from the formation of a collaborative team may feel overwhelmed by the prospect of attempting to build and maintain a research group. We propose this simple guide for starting and maintaining such an enterprise
Polymerization-Induced Phase-Separation in a Liquid-Crystal-Polymer Mixture
We have used light scattering to study the kinetics of polymerization-induced phase separation in a liquid-crystal-polymer mixture. The evolution of the structure factor is compared with scaling predictions for thermally quenched systems. We have also observed a cascading phenomenon where phase separated domains become unstable and undergo phase separation for a second time
Development of clinical pathways for anxiety and depression for patients with cancer in Australia
Hip and Trunk Muscle Activity During the Star Excursion Balance Test in Healthy Adults
CONTEXT: Dynamic balance is a measure of core stability. Deficits in the dynamic balance have been related to injuries in the athletic populations. The Star Excursion Balance Test (SEBT) is suggested to measure and improve dynamic balance when used as a rehabilitative tool.
OBJECTIVE: To determine the electromyographic activity of the hip and the trunk muscles during the SEBT.
DESIGN: Descriptive.
SETTING: University campus.
PARTICIPANTS: Twenty-two healthy adults (11 males and 11 females; 23.3 [3.8] y, 170.3 [7.6] cm, 67.8 [10.3] kg, and 15.1% [5.0%] body fat).
INTERVENTION: Surface electromyographic data were collected on 22 healthy adults of the erector spinae, external oblique, and rectus abdominis bilaterally, and gluteus medius and gluteus maximus muscle of the stance leg. A 2-way repeated measures analysis of variance was used to determine the interaction between the percentage maximal voluntary isometric contraction (%MVIC) and the reach directions. The %MVIC for each muscle was compared across the 8 reach directions using the Sidak post hoc test with α at .05. MAIN OUTCOME MEASURES: %MVIC.
RESULTS: Significant differences were observed for all the 8 muscles. Highest electromyographic activity was found for the tested muscles in the following reach directions-ipsilateral external oblique (44.5% [38.4%]): anterolateral; contralateral external oblique (52.3% [40.8%]): medial; ipsilateral rectus abdominis (8% [6.6%]): anterior; contralateral rectus abdominis (8% [5.3%]): anteromedial; ipsilateral erector spinae (46.4% [20.2%]): posterolateral; contralateral erector spinae (33.5% [11.3%]): posteromedial; gluteus maximus (27.4% [11.7%]): posterior; and gluteus medius (54.6% [26.1%]): medial direction.
CONCLUSIONS: Trunk and hip muscle activation was direction dependent during the SEBT. This information can be used during rehabilitation of the hip and the trunk muscles
Muscle Activity During the Star Excursion Balance Test in Healthy Adults
Purpose: To determine electromyographic (EMG) activity of the hip and the trunk muscles during the Star Excursion Balance Test (SEBT) performance in 8 reach directions
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Light-triggered CO release from nanoporous non-wovens
The water insoluble and photoactive CO releasing molecule dimanganese decacarbonyl (CORM-1) has been non-covalently embedded into poly(l-lactide-co-d/ l-lactide) fibers via electrospinning to enable bioavailability and water accessibility of CORM-1. SEM images of the resulting hybrid non-wovens reveal a nanoporous fiber morphology. Slight CO release from the CORM-1 in the electrospinning process induces nanoporosity. IR spectra show the same set of carbonyl bands for the CORM-1 precursor and the non-woven. When the material was exposed to light (365-480 nm), CO release from the incorporated CORM-1 was measured via heterogeneous myoglobin assay, a portable CO electrode and an IR gas cuvette. The CO release rate was wavelength dependent. Irradiation at 365 nm resulted in four times faster release than at 480 nm. 3.4 μmol of CO per mg non-woven can be generated. Mouse fibroblast 3T3 cells were used to show that the hybrid material is non-toxic in the darkness and strongly photocytotoxic when light is applied
Qualitative methods: are you enchanted or are you alienated?
Copyright © 2007 SAGE Publications. Author's draft version; post-print. Final version published by Sage available on Sage Journals Online http://online.sagepub.com/Since the last report on qualitative methods
(Crang, 2005), many of the practical procedures
of doing qualitative research remain the
same. Human geographers continue to study
texts, to conduct interviews, to convene focus
groups and to engage in ethnography. Indeed,
it is hard, though perhaps not impossible,
to imagine what a radically new form of
qualitative research practice might look like.
So, for the time being, this suite of methods
remains the backbone of qualitative research in
human geography. Yet we would like to contend
that, while these activities continue as
before, there are changes in the way they are
being conceived and carried out, and related to
this there are transformations in the way these
methods are being used to make claims to
understanding and intervening in the world. In
the first of our three reports, it is this link
between qualitative methodologies and interpretative
strategies we would like to reflect on
Detection of somatic changes in human cancer DNA by DNA fingerprint analysis.
Minisatellite DNA probes which can detect a large number of autosomal loci dispersed throughout the human genome were used to examine the constitutional and tumour DNA of 35 patients with a variety of cancers of which eight were of gastrointestinal origin. Somatic changes were seen in the tumour DNA in ten of the 35 cases. The changes included alterations in the relative intensities of hybridising DNA fragments, and, in three cases of cancers of gastrointestinal origin, the appearance of novel minisatellite fragments not seen in the corresponding constitutional DNA. The results of this preliminary study suggests that DNA fingerprint analysis provides a useful technique for identifying somatic changes in cancers
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