Search results for "AA"

Thiourea Organocatalysts as Emerging Chiral Pollutants: En Route to Porphyrin-Based (Chir)Optical Sensing

2021

Environmental pollution with chiral organic compounds is an emerging problem requiring innovative sensing methods. Amino-functionalized thioureas, such as 2-(dimethylamino)cyclohexyl-(3,5-bis(trifluoromethyl)phenyl)thiourea (Takemoto’s catalyst), are widely used organocatalysts with virtually unknown environmental safety data. Ecotoxicity studies based on the Vibrio fischeri luminescence inhibition test reveal significant toxicity of Takemoto’s catalyst (EC50 = 7.9 mg/L) and its NH2-substituted analog (EC50 = 7.2–7.4 mg/L). The observed toxic effect was pronounced by the influence of the trifluoromethyl moiety. En route to the porphyrin-based chemosensing of Takemoto-type thioureas, their s…

Kuoleman arvoituksesta elämän mysteeriin : Paul Austerin City of Glass salapoliisiromaanin parodiana

1999

Rethinking Civil Society in Development: Scales and Situated Hegemonies

2016

Ethnic residential segregation is often explained with the claim that ‘immigrants don’t want to integrate—they prefer to stick together with co-ethnics’. By contrast, mixed neighbourhoods are seen as crucial for achieving social cohesion. In line with spatial assimilation theory there is a normative assumption that people interact with those living nearby. From interviews on neighbourhood qualities and locations valued by Oslo residents of Turkish, Somali and Polish backgrounds, we raise questions about the validity of two assumptions: that most immigrants want to live in the same neighbourhoods as co-ethnics; and that they want to live close to co-ethnics because they do not want to integr…

Visual literacy practices in higher education: what, why and how?

2019

A bilingual five-year-old girl is trying to explain to her mother what she was doing at gymnastics class. Despite her best efforts to overcome the excitement, speaking a mixture of two languages an...

Extended music education enhances the quality of school life

2013

The claim of whether music education can create social benefits in the school environment was tested in 10 Finnish schools with an extended music curricular class and control classes. The quality of school life (QSL) was assessed by a representative sample (N=735) of pupils at years 3 and 6 (9- and 12-years-olds). The results showed that extended music education enhances the QSL, particularly in areas related to general satisfaction about the school and a sense of achievement and opportunity for students. Differences related to the schools and gender did not account for the results. A follow-up study examined whether the increase in critical QSL variables was related to music. This analysis…

Systematisation of Systems Solving Physics Boundary Value Problems

2020

A general conservation law that defines a class of physical field theories is constructed. First, the notion of a general field is introduced as a formal sum of differential forms on a Minkowski manifold. By the action principle the conservation law is defined for such a general field. By construction, particular field notions of physics, e.g., magnetic flux, electric field strength, stress, strain etc. become instances of the general field. Hence, the differential equations that constitute physical field theories become also instances of the general conservation law. The general field and the general conservation law together correspond to a large class of relativistic hyperbolic physical …

Disorder and interactions in systems out of equilibrium : the exact independent-particle picture from density functional theory

2017

Density functional theory (DFT) exploits an independent-particle-system construction to replicate the densities and current of an interacting system. This construction is used here to access the exact effective potential and bias of non-equilibrium systems with disorder and interactions. Our results show that interactions smoothen the effective disorder landscape, but do not necessarily increase the current, due to the competition of disorder screening and effective bias. This puts forward DFT as a diagnostic tool to understand disorder screening in a wide class of interacting disordered systems.

A two-phase problem with Robin conditions on the free boundary

2020

We study for the first time a two-phase free boundary problem in which the solution satisfies a Robin boundary condition. We consider the case in which the solution is continuous across the free boundary and we prove an existence and a regularity result for minimizers of the associated variational problem. Finally, in the appendix, we give an example of a class of Steiner symmetric minimizers. peerReviewed

Impact of chaotic dynamics on the performance of metaheuristic optimization algorithms : An experimental analysis

2022

Random mechanisms including mutations are an internal part of evolutionary algorithms, which are based on the fundamental ideas of Darwin's theory of evolution as well as Mendel's theory of genetic heritage. In this paper, we debate whether pseudo-random processes are needed for evolutionary algorithms or whether deterministic chaos, which is not a random process, can be suitably used instead. Specifically, we compare the performance of 10 evolutionary algorithms driven by chaotic dynamics and pseudo-random number generators using chaotic processes as a comparative study. In this study, the logistic equation is employed for generating periodical sequences of different lengths, which are use…

Approximating hidden chaotic attractors via parameter switching.

2018

In this paper, the problem of approximating hidden chaotic attractors of a general class of nonlinear systems is investigated. The parameter switching (PS) algorithm is utilized, which switches the control parameter within a given set of values with the initial value problem numerically solved. The PS-generated attractor approximates the attractor obtained by averaging the control parameter with the switched values, which represents the hidden chaotic attractor. The hidden chaotic attractors of a generalized Lorenz system and the Rabinovich-Fabrikant system are simulated for illustration. In Refs. 1–3, it is proved that the attractors of a chaotic system, considered as the unique numerical …