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In the search for low greenhouse gas propulsion, the dual fuel engine provides a solution to use low carbon fuel at diesel-like high efficiency. Also a lower emission of NOx and particles can be achieved by replacing a substantial part of the diesel fuel by for example natural gas. Limitations can be found in excessively high heat release rate (combustion-knock), and high methane emissions. These
In partially premixed combustion engines high octane number fuels are injected into the cylinder during the late part of the compression cycle, giving the fuel and oxidizer enough time to mix into a desirable stratified mixture. If ignited by auto-ignition such a gas composition can react in a combustion mode dominated by ignition wave propagation. 3D-CFD modeling of such a combustion mode is chal
Methanol is a genuine candidate on the alternative fuel market for internal combustion engines, especially within the heavy-duty transportation sector. Partially premixed combustion (PPC) engine concept, known for its high efficiency and low emission rates, can be promoted further with methanol fuel due to its unique thermo-physical properties. The low stoichiometric air to fuel ratio allows to ut
The present work describes the numerical modeling of medium-speed marine engines, operating in a fumigated dual-fuel mode, i.e. with the second fuel injected in the ports. This engine technology allows reducing engine-out emissions while maintaining the engine efficiency and can be fairly easily retrofitted from current diesel engines. The main premixed fuel that is added can be a low-carbon one a
Although references to China were few and fragmentary, the example of a ‘stationary’ East Asian Empire featured importantly in Scottish Enlightenment ideas about religion and political economy. David Hume considered whether the apparently long-flourishing system of Chinese government, grounded in rationally deduced deistic ethics, could provide an example for Western nations. Later in the eighteen
Focusing on artful, embodied listening as a method of analysing the emotional intensities of place, this article calls for academic geographers to listen to practitioners of nonacademic geography. It explores an ethical and methodological agenda for understanding how pop musicians have heard the world, and for taking them seriously as creative geographers who contribute sophisticated interpretatio
Purpose To study the epidemiology of Dupuytren disease and evaluate treatment outcome of collagenase injections using a modified method.Patients and methods Paper I is a register-based study. From the general population of Skåne region (1.3 million) in southern Sweden, we identified all residents aged ≥20 years who had been diagnosed with Dupuytren disease during a 16-year period and identified tr
This paper examines the place of women’s geographical reading in a centre of Enlightenment: Edinburgh, 1770–1810. It analyses two sets of booksellers’ records to identify key sites – women’s private libraries, Georgian domestic spaces, and women’s schools and boarding houses – in which women engaged with the geographical materials sold in the city’s bookshops: maps, globes, travel accounts, gazett
In this paper, computation fluid dynamics (CFD) simulations are performed to describe the effect of in-cylinder flow structures on the formation and oxidation of soot in a swirl-supported light-duty diesel engine. The focus of the paper is on the effect of swirl motion and injection pressure on late cycle soot oxidation. The structure of the flow at different swirl numbers is studied to investigat
Two-particle correlations in high-energy collision experiments enable the extraction of particle source radii by using the Bose-Einstein enhancement of pion production at low relative momentum q ∝ 1/R. It was previously observed that in pp collisions at s = 7TeV the average pair transverse momentum kT range of such analyses is limited due to large background correlations which were attributed to m
Two-color ionization is a powerful method for characterizing light fields and investigating atomic and molecular physics with attosecond sources based on High Harmonic Generation (HHG). Depending on the time duration of the light fields, two main techniques have been established: streaking [1], appropriate in the regime where a single attosecond pulse is generated, and RABBIT, used instead when a
Ultrashort laser pulses have become an indispensable tool in physics, chemistry and engineering. Their numerous applications call for accurate and robust characterization techniques able to reliably retrieve the pulse's intensity profile. Different methods, such as FROG [1] or SPIDER [2] and their variants, have been developed in past decades and are now common in many laboratories. More novel app
The interaction of atoms with intense laser radiation leads to the generation of high-order harmonics of the laser field. In the time domain, this corresponds to a train of pulses in the extreme ultraviolet range and with attosecond duration. This tutorial will introduce the physics of high-order harmonic generation and attosecond pulses.
Efficient, diode-pumped high energy femtosecond laser systems around 1 μm based on Yb-gain media are readily commercially available. However, owing to the gain bandwidth limitations, the pulses generated in such lasers are substantially longer than the ones generated in Ti:Sapphire systems. A simple, energy-scalable pulse self-compression scheme for the pulses around 1 μm thus would be of great in
Manipulation of electrons by light forms the basis for future optoelectronic devices targeting switching speeds close to optical frequencies. Specifically, nanolocalized optical and plasmonic fields play a key role as they reduce the interaction region down to few nanometers and thus the time electrons require to traverse the fields. In this context, the precise knowledge of the localized fields i
The ever-increasing worldwide environmental awareness has prompted much effort to minimize humanity's ecological footprint. This has led to increased demands for reliable technologies for assessing the current situation as well as the efficiency of new policies and interventions. In particular, CO2-monitoring has attracted lots of attention as CO2 is the greenhouse gas that is emitted in the large
