146 research outputs found
Effect of a Modified Isoindole Backbone on the Electrical Optical and Physical Properties of the Isoindole Organised Semiconductor System
Primarily it was endeavoured to synthesise conducting polymers bearing a modified isoindole backbone with potentially enhanced electrical, optical and physical properties. The addition of electron donating methoxy groups on to the N-methylisoindole system results in alternations to the resultant polymer’s optical and physical properties. The synthesis of the new compounds 5-methoxy-N-methylisoindole and 5, 6-dimethoxy-N-methylisoindole was carried out via a devised route. Characterisation of the two new monomers 5-methoxy-N-methylisoindole and 5,6-dimethoxy-N-methylisoindole and the parent N-methylisoindole and their corresponding polymers has also been carried out initially by cyclic voltammetry studies. The oxidation of the monomers and corresponding polymers occurs at decreasing positive potentials with the addition of the methoxy groups. Variation in the dopant anion incorporated into the polymer has also lead to alteration of the polymer properties. The novel poly-5, 6 dimethoxy-N-methylisoindole appears to be potentially a soluble organics conductor with rather interesting electrical properties. Subsequent characterisation of these materials to obtain an insight to their mechanistic properties was carried out. Along with cyclic voltammetry, the nucleation process occurring during polymerisation was studied with current vs time transients. Also cation exchange studies have been carried out. Finally in situ spectroelectrochemical properties of polymers are studied and analysed using the Nernst equation. The band gap of the neutral poly-5-methoxy-N-methylisoindole and poly-5, 6-dimethoxy-N-methylisoindole was determined to be ~2.36 eV and ~2.38 eV respectively
I Believe I Can φ
We propose a new analysis of ability modals. After briefly criticizing extant approaches, we turn our attention to the venerable but vexed conditional analysis of ability ascriptions. We give an account that builds on the conditional analysis, but avoids its weaknesses by incorporating a layer of quantification over a contextually supplied set of actions
Discrete Effects in Stellar Feedback: Individual Supernovae, Hypernovae, and IMF Sampling in Dwarf Galaxies
Using high-resolution simulations from the FIRE-2 (Feedback In Realistic
Environments) project, we study the effects of discreteness in stellar feedback
processes on the evolution of galaxies and the properties of the interstellar
medium (ISM). We specifically consider the discretization of supernovae (SNe),
including hypernovae (HNe), and sampling the initial mass function (IMF). We
study these processes in cosmological simulations of dwarf galaxies with
stellar masses (halo masses ). We show that the discrete nature of individual SNe
(as opposed to a model in which their energy/momentum deposition is continuous
over time, similar to stellar winds) is crucial in generating a reasonable ISM
structure and galactic winds and in regulating dwarf stellar masses. However,
once SNe are discretized, accounting for the effects of IMF sampling on
continuous mechanisms such as radiative feedback and stellar mass-loss (as
opposed to adopting IMF-averaged rates) has weak effects on galaxy-scale
properties. We also consider the effects of rare HNe events with energies . The effects of HNe are similar to the effects of clustered
explosions of SNe -- which are already captured in our default simulation setup
-- and do not quench star formation (provided that the HNe do not dominate the
total SNe energy budget), which suggests that HNe yield products should be
observable in ultra-faint dwarfs today.Comment: 9 pages, 4 figure
- …