A Numerical Study on the Effects of the Geometry and Location of an Inserted Wire on Methane–Air Flames in a Micro–Burner

The effects of the diameter and location of an inserted wire on methane–air flame characteristics in a micro-burner, with a backward-facing step, were investigated numerically. Our goal was to shed light on the parameters that the authors had not already considered in the previous study. To do so, the effects of the studied parameters on the flame location and distribution of temperature, H, and OH species, were scrutinized. It was shown that increasing the inserted wire’s diameter and relocating the inserted wire towards the outlet had polynomial and linear effects on the flame location in the burner, respectively. Although changing these two parameters did not have any obvious effects on the maximum temperature of the auxiliary axis in the burner or the external wall, effects on the peak values of the hot-flame critical chemical species of OH and H were recognized. Furthermore, it was shown that the temperature distribution on the outer surface of the burner was more influenced by the wire’s axial location in the burner, rather than the wire’s diameter. This effect may be of interest for designing micro-TPVs or micro-TEGs.

ON THE STABILITY OF FAST FERRY IN DAMAGE SCENARIOS

The ro-ro ships are characterized by a large garage compartment extending from stern to bow. Damage conditions, heavy weather and large floodable spaces could create serious accidents, with the loss of life and goods at sea, both for conventional ferries and fast ferries. The occurred accidents showed the need of a more accurate approach to the damaged ship stability in waves, also in head sea and following sea conditions, because of the great movements of water on the car deck. With this aim a tool for analysing the ship response in wave with damaged compartments has been developed and applied on a typical fast ferry. The ship dynamic is simulated in time domain, including non-linear effects, taking into account critical scenarios on the damaged ship. The applications regard ship grounding, assuming head sea, modelled by regular wave. In addition to that, also the particularly critical condition of a transversal wind heeling moment has been applied to compute non symmetrical behaviour. Moreover the stability problems arising from the presence of trapped water in the garage compartment are investigated assuming the same environmental scenarios.

Bilingual experiences induce dynamic structural changes to basal ganglia and the thalamus

Bilingualism has been linked to structural adaptations of subcortical brain regions that are important nodes in controlling of multiple languages. However, research on the location and extent of these adaptations has yielded variable patterns. Existing literature on bilingualism-induced brain adaptations has so far largely overseen evidence from other domains that experience-based structural neuroplasticity often triggers non-linear adaptations which follow expansion-renormalisation trajectories. Here we use generalised additive mixed models (GAMMs) to investigate the non-linear effects of quantified bilingual experiences on the basal ganglia and thalamus in a sample of bilinguals with wide range of bilingual experiences. Our results revealed that volumes of bilateral caudate nuclei and accumbens were positively related to bilingual experiences in a non-linear pattern, with increases followed by decreases, in the most experienced bilinguals, suggesting a return to baseline volume at higher levels of bilingual experience. Moreover, volumes of putamen and thalamus were positively linearly predicted by bilingual experiences. The results offer the first direct evidence that bilingualism, similarly to other cognitively demanding skills, leads to dynamic subcortical structural adaptations which can be nonlinear, in line with expansion-renormalisation models of experience-dependent neuroplasticity.

Effects of Mode Dispersion on Cross-phase modulation on Mode Division Multiplexed Optical Fibers

<div>The concept of mode division multiplexing also known as space division multiplexing was introduced as an alternative to combat the approaching capacity crunch in single mode fibers. Just like single mode fibers, space division multiplexed fibers will experience non-linearity at a different level and studies have shown that some linear effects can be beneficial in combating the nonlinear interference. This study aims to identify the benefits accrued when these linear effects are implemented by exploring the already existing models defined in the literature.</div>

Effects of Mode Dispersion on Cross-phase modulation on Mode Division Multiplexed Optical Fibers

<div>The concept of mode division multiplexing also known as space division multiplexing was introduced as an alternative to combat the approaching capacity crunch in single mode fibers. Just like single mode fibers, space division multiplexed fibers will experience non-linearity at a different level and studies have shown that some linear effects can be beneficial in combating the nonlinear interference. This study aims to identify the benefits accrued when these linear effects are implemented by exploring the already existing models defined in the literature.</div>

Smallest remnants of early matter domination

The evolution of the universe prior to Big Bang Nucleosynthesis could have gone through a phase of early matter domination which enhanced the growth of small-scale dark matter structure. If this period was long enough, self-gravitating objects formed prior to reheating. We study the evolution of these dense early halos through reheating. At the end of early matter domination, the early halos undergo rapid expansion and eventually eject their matter. We find that this process washes out structure on scales much larger than naively expected from the size of the original halos. We compute the density profiles of the early halo remnants and use them to construct late-time power spectra that include these non-linear effects. We evolve the resulting power spectrum to estimate the properties of microhalos that would form after matter-radiation equality. Surprisingly, cosmologies with a short period of early matter domination lead to an earlier onset of microhalo formation compared to those with a long period. In either case, dark matter structure formation begins much earlier than in the standard cosmology, with most dark matter bound in microhalos in the late universe.