Influence of spray-glow plug configuration on cold start combustion for high-speed direct injection diesel engines

Glow plugs are currently the most employed solution to promote ignition in light-duty diesel engines during low temperature cold start. Improved knowledge about the mechanisms that control ignition and flame development under such conditions is necessary for design purposes, especially with current trends to reduce engine compression ratio. This paper aims to analyze the influence of the glow plug configuration (location and temperature) on cold start combustion. Experimental tests carried out in an optical engine with high speed visualization have confirmed that spray-glow plug configuration influences the whole combustion process through pilot ignition. Ignition of pilot injection is controlled by glow plug to spray distance, by glow plug temperature and by fuel and air motion after the end of injection. Nevertheless, glow plug temperature effect starts to be negligible above a certain value, since chemical ignition delay cannot be further reduced. © 2011 Elsevier Ltd.Pastor Soriano, JV.; Bermúdez, V.; García Oliver, JM.; Ramírez Hernández, JG. (2011). Influence of spray-glow plug configuration on cold start combustion for high-speed direct injection diesel engines. Energy. 36(9):5486-5496. doi:10.1016/j.energy.2011.07.028S5486549636

Etude des verres d'oxydes par dynamique moléculaire à champ de force polarisable et RMN premiers principes

International audienc

New insights into oxide glass structure from a combined experimental and computational solid-state NMR approach

International audienc

Microlasers autodoubleurs en Nd:GdCOB

Nous avons réalisé des microlasers pompés par diode à émission dans le visible, à partir d'un matériau autodoubleur (Nd:GdCOB) qui possède simultanément des propriétés laser et non linéaires. La fabrication de ces microlasers nécessite une orientation fine des faces des cristaux perpendiculairement à la direction d'accord de phase, avec une précision de t 0,1 °. Des miroirs diéléctriques sont déposés sur chaque face. Cette technologie assure une fabrication collective de faible coût. En pompage par diode, une puissance de 21 mW à 530 nm a été atteinte pour une puissance de pompe incidente à 812 nm de 1,4 W. Pour une puissance de pompe réduite de 0,7 W, la puissance émise dans le vert atteint 3 mW, et le profil spatial reste monomode transverse. Ces résultats encourageants sont une nouvelle étape vers la réalisation de sources visibles compactes et bas coût

Corneal Confocal Microscopy Predicts the Development of Diabetic Neuropathy : A Longitudinal Diagnostic Multinational Consortium Study

OBJECTIVE: Corneal nerve fiber length (CNFL) has been shown in research studies to identify diabetic peripheral neuropathy (DPN). In this longitudinal diagnostic study, we assessed the ability of CNFL to predict the development of DPN. RESEARCH DESIGN AND METHODS: From a multinational cohort of 998 participants with type 1 and type 2 diabetes, we studied the subset of 261 participants who were free of DPN at baseline and completed at least 4 years of follow-up for incident DPN. The predictive validity of CNFL for the development of DPN was determined using time-dependent receiver operating characteristic (ROC) curves. RESULTS: A total of 203 participants had type 1 and 58 had type 2 diabetes. Mean follow-up time was 5.8 years (interquartile range 4.2-7.0). New-onset DPN occurred in 60 participants (23%; 4.29 events per 100 person-years). Participants who developed DPN were older and had a higher prevalence of type 2 diabetes, higher BMI, and longer duration of diabetes. The baseline electrophysiology and corneal confocal microscopy parameters were in the normal range but were all significantly lower in participants who developed DPN. The time-dependent area under the ROC curve for CNFL ranged between 0.61 and 0.69 for years 1-5 and was 0.80 at year 6. The optimal diagnostic threshold for a baseline CNFL of 14.1 mm/mm2 was associated with 67% sensitivity, 71% specificity, and a hazard ratio of 2.95 (95% CI 1.70-5.11; P < 0.001) for new-onset DPN. CONCLUSIONS: CNFL showed good predictive validity for identifying patients at higher risk of developing DPN ∼6 years in the future.</p