Investigations on spark pre-chamber ignition and subsequent turbulent jet main chamber ignition in a novel optically accessible test rig

2021 ◽  
pp. 146808742110198
Author(s):  
Walter Vera-Tudela ◽  
Christophe Barro ◽  
Konstantinos Boulouchos
Keyword(s):  
Boundary Conditions ◽  
Heat Release ◽  
Turbulent Jet ◽  
The Other ◽  
Frame Rate ◽  
Main Chamber ◽  
Test Rig ◽  
Other Hand ◽  
Wide Range ◽  
Ignition And Combustion

Turbulent jet ignition (TJI) is a promising strategy to ignite diluted air-fuel mixtures; this is usually generated by igniting a fraction of the mixture inside a small pre-chamber. Nevertheless, the processes that take place inside the pre-chamber, as well as the injection of the turbulent jet into the main chamber and its subsequent re-ignition are not fully understood. The current work presents an experimental investigation that studies the effects of the nozzle size, turbulence level, and air-fuel mixture on the pre-chamber ignition and main chamber re-ignition and combustion. To accomplish this, a series of experiments have been carried out under different boundary conditions. To understand the phenomena taking place in the pre- and main chamber, two different approaches were taken: On one hand, (1) pressure-based diagnostics were applied by fitting a pressure sensor in each of the chambers. This was done to trace the pressure evolution during the whole combustion event and to calculate the heat-release. On the other hand, (2) optical diagnostics were setup on both combustion chambers, using dual schlieren setups synchronized at the same frame rate. The optically accessible test rig and the combination of schlieren in the pre-chamber (PC) & main-chamber (MC) allows to visualize the ignition, flame propagation, quenching mechanisms and re-ignition under a wide range of boundary conditions. This combined with the pressure traces and heat-release give a full understanding of the ignition and combustion processes. Higher turbulence levels and equivalence ratios increase the propagation of the flame front and the peak pressure in the pre-chamber. The resulting higher nozzle-exit velocities lead, on one hand, to faster mixing and therefore to a larger portion of main chamber fuel within the jet, which decrease the main chamber combustion duration. On the other hand, to high quenching and longer re-ignition times, which show the adverse effect.

scholarly journals The Synergy of Two Biofuel Additives on Combustion Process to Simultaneously Reduce NOx and PM Emissions

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2784
Author(s):  
Jerzy Cisek ◽  
Szymon Lesniak ◽  
Winicjusz Stanik ◽  
Włodzimierz Przybylski
Keyword(s):  
Heat Release ◽  
Combustion Rate ◽  
Combustion Process ◽  
The Other ◽  
Fuel Additive ◽  
Exhaust Gas ◽  
Synergy Effect ◽  
Engine Exhaust ◽  
Other Hand ◽  
Heat Released

The article presents the results of research on the influence of two fuel additives that selectively affect the combustion process in a diesel engine cylinder. The addition of NitrON® reduces the concentration of nitrogen oxides (NOx), due to a reduction in the kinetic combustion rate, at the cost of a slight increase in the concentration of particulate matter (PM) in the engine exhaust gas. The Reduxco® additive reduces PM emissions by increasing the diffusion combustion rate, while slightly increasing the NOx concentration in the engine exhaust gas. Research conducted by the authors confirmed that the simultaneous use of both of these additives in the fuel not only reduced both NOx and PM emissions in the exhaust gas but additionally the reduction of NOx and PM emissions was greater than the sum of the effects of these additives—the synergy effect. Findings indicated that the waveforms of the heat release rate (dQ/dα) responsible for the emission of NOx and PM in the exhaust gas differed for the four tested fuels in relation to the maximum value (selectively and independently in the kinetic and diffusion stage), and they were also phase shifted. Due to this, the heat release process Q(α) was characterized by a lower amount of heat released in the kinetic phase compared to fuel with NitrON® only and a greater amount of heat released in the diffusion phase compared to fuel with Reduxco® alone, which explained the lowest NOx and PM emissions in the exhaust gas at that time. For example for the NOx concentration in the engine exhaust: the Nitrocet® fuel additive (in the used amount of 1500 ppm) reduces the NOx concentration in the exhaust gas by 18% compared to the base fuel. The addition of a Reduxco® catalyst to the fuel (1500 ppm) unfortunately increases the NOx concentration by up to 20%. On the other hand, the combustion of the complete tested fuel, containing both additives simultaneously, is characterized, thanks to the synergy effect, by the lowest NOx concentration (reduction by 22% in relation to the base). For example for PM emissions: the Nitrocet® fuel additive does not significantly affect the PM emissions in the engine exhaust (up to a few per cent compared to the base fuel). The addition of a Reduxco® catalyst to the fuel greatly reduces PM emissions in the engine exhaust, up to 35% compared to the base fuel. On the other hand, the combustion of the complete tested fuel containing both additives simultaneously is characterized by the synergy effect with the lowest PM emission (reduction of 39% compared to the base fuel).

Reactions of polar dienes with o-quinones

1989 ◽  
Vol 67 (8) ◽  
pp. 1354-1358 ◽  
Author(s):  
Jacques Paquet ◽  
Paul Brassard
Keyword(s):  
The Other ◽  
Other Hand ◽  
Wide Range ◽  
Ketene Acetal

The behaviour of various types of polar dienes towards halogenated ortho quinones has been investigated in a number of representative cases. As compared to the commonly used para analogues, o-quinones provide a wide range of products that indicate a keener response to the nature, number, and position of substituents on both reactants. 3-Halogenated-o-naphthoquinones 1 and 2 react smoothly with a representative vinologous ketene acetal 3, vinylketene acetals 4 and 5, and a monooxygenated diene 6 to provide variously substituted phenanthrenequinones 7–11. Only monooxygenated dienes on the other hand add to o-benzoquinones 14–16 and give convenient syntheses of the corresponding o-naphthoquinones 18–20. Keywords: cycloaddition, o-naphthoquinones, phenanthrenequinones, regiospecificity.

The Council of Trent Revisited

2002 ◽  
Vol 55 (1) ◽  
pp. 1-37 ◽  
Author(s):  
Craig A. Monson
Keyword(s):  
The Other ◽  
Council Of Trent ◽  
Local Authorities ◽  
Other Hand ◽  
Wide Range ◽  
Official Status

Abstract Reexamination of a wide range of documents surrounding the twenty-second, twenty-fourth, and twenty-fifth sessions of the Council of Trent reveals that delegates strived officially to say as little as possible about music: only that secular or impure elements should be eliminated and that specific issues should be settled locally, by individual bishops and provincial synods. But, beginning with Gustave Reese, several scholars have misleadingly strung together a preliminary canon, stressing textual intelligibility, which was never approved in the general congregations, and the few lines that actually supplanted it, concerned only with the elimination of lasciviousness. On the other hand, a largely unrecognized or misunderstood attack on church polyphony did occur at the less familiar twenty-fifth session, when Gabriele Paleotti may have attempted to suppress elaborate music in female monasteries. Although this attempt was rejected in the general congregations, its restrictions were subsequently revived by local authorities such as Paleotti and Carlo Borromeo in their own dioceses. In the Council's immediate aftermath, reformers such as Paleotti and Borromeo once again focused on the issue of intelligibility, affording it a quasi-official status that seems to have quickly become widely accepted as “iuxta formam concilii.”

Diversification of α–Ketoamides via Transamidation Reactions with Alkyl and Benzyl Amines at Room Temperature

2021 ◽  
Author(s):  
Shweta Singh ◽  
Sureshbabu Popuri ◽  
Qazi Mohammad Junaid ◽  
Sabiah Shahul Hameed ◽  
Jeyakumar Kandasamy
Keyword(s):  
Room Temperature ◽  
The Other ◽  
Alkyl Amines ◽  
Other Hand ◽  
Wide Range

A wide range of N-tosyl α–ketoamides underwent transamidation with various alkyl amines in the absence of catalyst, base, or additives. On the other hand, transamidation in N-Boc α–ketoamides is achieved...

scholarly journals Złożenie skargi przez konsumenta za pośrednictwem ODR (Online Dispute Resolution) – internetowego systemu rozstrzygania sporów

2019 ◽  
Vol 17 (1) ◽  
pp. 183-194
Author(s):  
Anna Rogacka-Łukasik
Keyword(s):  
Dispute Resolution ◽  
Alternative Dispute Resolution ◽  
The Other ◽  
Online Dispute Resolution ◽  
Other Hand ◽  
Resolution System ◽  
Wide Range ◽  
Technical Innovations ◽  
Modern Form ◽  
Dispute Resolution System

ADR (Alternative Dispute Resolution), as a non-judicial resolution of disputes, is a wide range of mechanisms that aim to put an end to a conflict without the need of conducting a trial before the court. On the other hand, the modern form of ADR is ODR (Online Dispute Resolution) – an online dispute resolution system that is the expression of the newest means of communication and technical innovations in order to help in non-judicial dispute resolving. The goal of this publication is to present the ODR platform and, in particular, to describe the process of filing a complaint by the consumer by means of it.

Linear Stability of a Plasma Diode

1969 ◽  
Vol 24 (8) ◽  
pp. 1235-1243 ◽  
Author(s):  
M Dobrowolny ◽  
F Engelmann ◽  
A Sestero
Keyword(s):  
Boundary Conditions ◽  
Linear Stability ◽  
Plane Waves ◽  
The Other ◽  
Other Hand ◽  
Free Particles ◽  
Plasma Diode ◽  
The Stability

AbstractThe stability of a plasma diode with respect to longitudinal oscillations is investigated. If there are free particles emitted by the electrodes, the perturbations do not have the same dynamics as they would in an infinite plasma, contrary to the case where only particles trapped in the diode are present. This can be interpreted as due to a coupling of plane waves of different wave lengths, introduced by the boundary conditions at the electrodes. The occurrence of resonant-particle effects, on the other hand, is subjected to precisely the same conditions as in an infinite plasma.

scholarly journals Hegel’s Lectures on the History of Modern Philosophy

2017 ◽  
Author(s):  
Karin de Boer
Keyword(s):  
Modern Philosophy ◽  
History Of Philosophy ◽  
The Other ◽  
Other Hand ◽  
Wide Range ◽  
History Of ◽  
Methodological Principles ◽  
The One

This chapter examines Hegel’s lectures on the history of modern philosophy in view of the tension between, on the one hand, his ambition to grasp philosophy’s past in a truly philosophical way and, on the other hand, the necessity to account for the actual particularities of a wide range of philosophical systems. Hegel’s lectures are put in relief by comparing their methodological principles to those put forward by his Kantian predecessor Tennemann. After discussing Hegel’s conception of modern philosophy as a whole, the chapter turns to his reading of Locke, Leibniz, and, in particular, Kant. In this context, it also compares Hegel’s assessment of Kant’s achievements to that of Tennemann. The chapter concludes by considering Hegel’s account of the final moment of the history of philosophy.

The Political Function of the Poro. (Part II.)

Africa ◽  
1966 ◽  
Vol 36 (1) ◽  
pp. 62-72 ◽  
Author(s):  
Kenneth Little
Keyword(s):  
The Other ◽  
The Political ◽  
Other Hand ◽  
Political Function ◽  
Wide Range ◽  
Opening Paragraph

Opening ParagraphIn the concluding paragraphs of Part I of this article it was pointed out that in addition to its judicial functions the Poro society possessed some important powers of administration. On the other hand, there was also evidence to suggest that the society carried on this wide range of activities, amounting almost to government of the country, as an instrument of the chiefs.

scholarly journals Orientation-Based Interaction on Mobile Devices and Desktops - An Evaluation

2017 ◽  
Vol 869 ◽  
pp. 244-262
Author(s):  
Johannes Schwank ◽  
Franca Alexandra Rupprecht ◽  
Sebastian Schöffel
Keyword(s):  
Mobile Devices ◽  
Mobile Device ◽  
The Other ◽  
Hand Tracking ◽  
Full Potential ◽  
Pilot Studies ◽  
Other Hand ◽  
Maximum Angle ◽  
Wide Range ◽  
Additional Input

Nowadays, mobile devices, such as smartphones, tablets or smartwatches, are essential items in our daily life. Further, more and more people use smart mobile devices in their everyday work for remote controlling, observing diagrams, performing web analytics, etc. However, the full potential of mobile devices is not tapped yet; built-in sensors such as accelerometers or gyroscopes offer a wide range of interaction capabilities, which are still often not fully used in nowadays mobile applications. On the other hand, desktops are still the dominating working device, but with significantly differing interaction means. With additional hand tracking devices capturing the user's gestures additional input possibilities are available but still often unused. In this paper, we investigate on a concept for orientation-based touch-less interaction. Depending on the type of device - traditional desktop or a mobile device - we use an interaction metaphor called "Waggle"; utilizing of tilting and turning of either the user's hand or the mobile device itself for additional input possibilities. Based on the results of two pilot studies for both environments, basic parameters for future design decisions are derived: on the one hand, the maximum angle for basic rotation axes are evaluated. On the other hand, different discretizations of tilt and turn angles are investigated. Based on the outcome of both studies the optimal configuration for the use of the Waggle interaction metaphor in future applications on both mobile and desktop environments are defined.

Indian Writing in English and the Discrepant Zones of World Literature

2017 ◽  
Vol 135 (1) ◽  
pp. 122-139
Author(s):  
Dirk Wiemann
Keyword(s):  
World Literature ◽  
The Other ◽  
International Visibility ◽  
Other Hand ◽  
Wide Range ◽  
Indian Writing In English ◽  
The One

AbstractFor world literature studies, Indian writing in English offers an exceptionally rich and variegated field of analysis: On the one hand, a set of prominent Indian or diasporic writers accrues substantial literary capital through metropolitan review circuits and award systems and thus maintains the high international visibility that Indian writing in English has acquired ever since the early 1980s. Addressing a readership that spans countries and continents, this kind of writing functions as a viable tributary to world literature. On the other hand, a new boom of Indian mass fiction in English has emerged that, while targeting a strictly domestic audience, is always already implicated in the dynamics of world literature as well, albeit in a very different way: As they deploy, appropriate and adopt a wide range of globally available templates of popular genres, these texts have globality inscribed into their very textures even if they do not circulate internationally.

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