The photoelectron spectra of the diazanaphthalenes

The high-resolution He 584 Å photoelectron spectra of ten diazanaphthalenes are presented. The ordering of the π orbitals and the nitrogen “lone-pair” orbitals is discussed. Several semi-empirical quantum-chemical calculation methods have been screened against the experimental evidence

Perfluoro effect in the photoelectron spectra of quinoline and isoquinoline

The high-resolution He 584Aophotoelectron spectra of heptafluoroquinoline and heptafluoroisoquinoline are compared with those of the parent compounds. Shifts in π ionisation potentials, due to the fluorine substitution, can be described with an inductive and a combined inductive-conjugative Hu¨ckel model

Photoelectron spectra of fluorine substituted diazanaphthalenes: “Even cases”

The high resolution He 584 Å photoelectron spectra of three diazanaphthalenes and some of their fluorine derivatives are presented. The qualitative model that is used frequently in the discussion of lone-pair level splittings is examined

Photoelectron spectra of some fluorine substituted diazanaphthalenes

The high resolution He 584 Å photoelectron spectra of fluorine substituted 1,2-diaza-, 1,3-diaza-, 1,4-diaza- and 2,3-diaza-naphthalene are presented. By means of fluorine substitution the analysis of the photoelectron spectra of the parent compounds can be made more definite. Unexpected shifts of the nitrogen “lone-pair” bands can be explained within the through-space and through-bond interaction model. From this explanation one can deduce that fluorine substitution can give experimental evidence about the symmetry character of the “lone-pair” molecular orbitals

Photoelectron spectra of fluorine-substituted diazabenzenes

The high resolution He 584 Å photoelectron spectra of ten fluorine-substituted diazabenzenes are presented. By means of fluorine substitution the analysis of the photoelectron spectra of the parent compounds can be made more definite. “Lone-pair” ionization potentials are shown to correlate well with data calculated by a modified and iterative version of the extended Hückel method

The Plant Propagation Algorithm on Timetables: First Results

One Stochastic HillClimber and two implementations of the Plant Propagation Algorithm (PPA-1 and PPA-2) are applied to an instance of the University Course Timetabling Problem from the Univer- sity of Amsterdam. After completing 10 runs of 200,000 objective function evaluations each, results show that PPA-1 outperforms the HillClimber, but PPA-2 makes the best timetables

Flow focusing through gels as a tool to generate 3D concentration profiles in hydrogel-filled microfluidic chips

Laminar flow patterning is an iconic microfluidic technology used to deliver chemicals to specific regions on a two-dimensional surface with high spatial fidelity. Here we present a novel extension of this technology using Darcy flow within a three-dimensional (3D) hydrogel. Our test device is a simple 3-inlet microfluidic channel, totally filled with collagen, a cured biological hydrogel, where the concentration profiles of solutes are manipulated via the inlet pressures. This method allows solutes to be delivered with 50 micron accuracy within the gel, as we evidence by controlling concentration profiles of 40 kDa and 1 kDa fluorescent polysaccharide dyes. Furthermore, we design and test a 3D-printed version of our device with an extra two inlets for control of the vertical position of the concentration profile, demonstrating that this method is easily extensible to control of the concentration profile in 3D

The sound of study:Student experiences of listening in the university soundscape

The students from three universities (Groningen, Oldenburg and the University of Applied Sciences in Utrecht) were surveyed on the experience of hearing and listening in their study. Included in the online survey were established questionnaires on hearing loss, tinnitus, hyperacusis, a subscale on psychosocial strain resulting from impaired hearing and a questionnaire about students’ perceptions of listening ease in study environments. Results from the 10,466 students who completed the survey (13% response rate) are highlighted, with particular attention to listening ease and measures proposed by students for improving it. A consequence from our findings is that more effective classroom practice may be won if study soundscapes can be improved, while universities might exercise greater inclusive responsibility for study as high quality sensory experience for the benefit of all students