1,084 research outputs found

    Laser ignition of iso-octane air aerosols

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    Iso-octane aerosols in air have been ignited with a focused Nd:YAG laser at pressures and temperatures of 100kPa and 270K and imaged using schlieren photography. The aerosol was generated using the Wilson cloud chamber technique. The droplet diameter, gas phase equivalence ratio and droplet number density were determined. The input laser energy and overall equivalence ratio were varied. For 270mJ pulse energies initial breakdown occurred at a number of sites along the laser beam axis. From measurements of the shock wave velocity it was found that energy was not deposited into the sites evenly. At pulse energies of 32mJ a single ignition site was observed. Overall fuel lean flames were observed to locally extinguish, however both stoichiometric and fuel rich flames were ignited. The minimum ignition energy was found to depend on the likelihood of a droplet existing at the focus of the laser beam

    Non-wetting drops at liquid interfaces: From liquid marbles to Leidenfrost drops

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    We consider the flotation of deformable, non-wetting drops on a liquid interface. We consider the deflection of both the liquid interface and the droplet itself in response to the buoyancy forces, density difference and the various surface tensions within the system. Our results suggest new insight into a range of phenomena in which such drops occur, including Leidenfrost droplets and floating liquid marbles. In particular, we show that the floating state of liquid marbles is very sensitive to the tension of the particle-covered interface and suggest that this sensitivity may make such experiments a useful assay of the properties of these complex interfaces.Comment: 21 pages, 9 figures. Minor typos correcte

    Application of PROMETHEE method for demand side management (DSM) options ranking

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    Demand Side Management (DSM) is a method used to modify the electrical load profile of a consumer to reduce its electricity bill. There are various types of DSM options available but mostly involve costs to be incurred by consumers. Moreover, the effectiveness of a DSM option depends on various factors including investment cost, saved energy, payback period and more. Multi Criteria Decision Analysis (MCDA) is a tool that can be applied to make decision when a lot of factors to be taken into account. In DSM, Analytical Hierarchy Process (AHP) is one MCDA technique that is widely used in ranking the DSM options. However, AHP requires additive aggregation that may cause lost in detailed information. This paper presents another MDCA method; Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) to perform the ranking of DSM options. PROMETHEE (I and II) were used in a case study and the results shows that PROMETHEE give the same result as AHP. PROMETHEE has an advantage over AHP as it does not require additive aggregation even the problem is multi-dimensional and could provide visual analysis

    Diagnostic and prognostic values of antikeratin antibodies (AKA) and collagen III propeptides (PIIINP) in juvenile rheumatoid arthritis

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    Background: The need for specific and sensitive diagnostic as well as prognostic markers for juvenile rheumatoid arthritis (JRA) has urged  scientific research toward this field.Objective: We sought to assess the diagnostic and prognostic values of serum and synovial fluid collagen III propeptides (PIIINP) and antikeratin antibodies(AKA) in JRA.Methods :Thirty-one JRA patients with a mean age of 10.6±4.2 years were enrolled in the study. They were compared to 10 SLE patients with arthritis and 15 age and sex matched healthy children as control groups. All  patients were subjected at enrollment to laboratory evaluation by CBC,  ESR, CRP, serum PIIINP and AKA. Patients with knee effusion were  subjected to AKA and PIIINP analysis in their synovial fluid samples. Clinical evaluation was done by examination of joint swelling, tenderness and limitation of movement scores. Also, radiological evaluation by plain X-ray films for hands, knees and feet using modified Larsen score (MLS) was performed. Laboratory, clinical and radiological evaluation methods were re-performed after 3 months of proper treatment. A third radiological evaluation was done one year after the first evaluation.Results: Serum PIIINP was significantly elevated in JRA patients  (12.8±8.7) ìg/L in comparison to healthy controls (7.0±1.9 ìg/L, p<0.05). However, no significant difference was observed when compared to SLE patients. Reduction of serum PIIINP was observed after 3 months of treatment with no significant difference between JRA patients (10.5±8.8 ìg/L) and the healthy controls. Synovial fluid PIIINP (56.4±6.6 ìg/L) was significantly higher than that of the serum (p<0.05). Neither serum nor synovial fluid PIIINP correlated with any of the laboratory, clinical or radiological parameters. The serum AKA positivity rate was significantly higher in JRA patients (77% at the study onset and 90% after three months) as compared to the control group (7%, p<0.001). Serum AKA values recorded a sensitivity, specificity and diagnostic efficiency in JRA patients of 77%, 93% and 83% at the study onset. These values increased after 3 months to 90%, 93% and 91% respectively. Synovial AKA levels displayed no significant difference in comparison to that of the serum.Conclusion :AKA is a specific and sensitive diagnostic marker for JRA. Meanwhile, PIIINP was significantly elevated during JRA disease activity particularly in the synovial fluid. Neither AKA nor PIIINP proved to have prognostic values in JRA.Key words: juvenile rheumatoid, arthritis, antikeratin antibodies, collagen III propeptides, SLE

    1,3-Diallyl-5-chloro-1H-benzimidazol-2(3H)-one

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    The benzimidazolone part of the title mol­ecule, C13H13ClN2O, is almost planar (r.m.s. deviation = 0.006 Å) and its mean plane is aligned at dihedral angles of 62.5 (1) and 78.0 (1)° with respect to the mean planes of the allyl substituents

    3-Allyl-1,5-dibenzyl-1,5-benzodiazepine-2,4-dione

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    The title compound, C26H24N2O2, features a benzene ring fused with a seven-membered diazepine ring; the latter ring adopts a boat conformation (with the allyl­dimethyl­amino­methyl-bearing C atom as the prow and the fused-ring C atoms as the stern)

    1,3-Dibenzyl-6-bromo-1H-imidazo[4,5-b]pyridin-2(3H)-one

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    The imidazopyridine fused-ring in the title compound, C20H16BrN3O, is planar (r.m.s. deviation = 0.011 Å). The phenyl rings of the benzyl substitutents twist away from the central five-membered ring in opposite directions; the rings are aligned at 61.3 (1) and 71.2 (1)° with respect to this ring

    3-[(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]-1,5-dimethyl-1,5-benzodiazepine-2,4-dione

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    The title compound, C21H21N5O2, is a 1,4-dimethyl-1,2,3-triazole having dimethyl­benzodiazepindione and phenyl substituents on each methyl group; the substituents are positioned on opposite sides of the five-membered ring. The seven-membered fused-ring of the larger substituent adopts a boat-shaped conformation (with the methine C atom as the prow)

    DRIVER RESPOND TO PRE-COLLISION SCENARIO AT INTERSECTION IN AUTONOMOUS VEHICLE

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    Research on automation system development is attracting a lot of attention from researchers, automotive industry manufacturers and leading technology brands. This study focus is on SAE level 3, the vehicle steering, accelerator pedal and brake pedal are controlled autonomously. The decrement in controlling vehicle and driving task has the possibility to reduce the road crash resulted in an essential change in driver role from active to passive. The effect of role change leads to decrement of situation awareness and reduce driver abilities to control manual vehicle at the right time and manner. Therefore, research on recognition times in complex and actual situations are critical. The primary purpose was to analyze the driver’s ability to recognize pedestrian, bicycle and vehicle pre-collision at intersection in the automated vehicle. The road conditions were complicated and imitated a real driving scenario. The statistical tools used for analysis were the F-test, t-test and ANOVA method. This finding shows that the subject can instantaneously recognize unintended acceleration at a low velocity and relative velocity in a pre-collision scenario with pedestrian. The implication of these results is in developing an automated vehicle system related to driver recognition. These findings provide insights that can be useful in developing autonomous vehicles
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