Search results for "amine"
showing 10 items of 7299 documents
Improving Password Memorability, While Not Inconveniencing the User
2019
Passwords are the most frequently used authentication mechanism. However, due to increased password numbers, there has been an increase in insecure password behaviors (e.g., password reuse). Therefore, new and innovative ways are needed to increase password memorability and security. Typically, users are asked to input their passwords once in order to access the system, and twice to verify the password, when they create a new account. But what if users were asked to input their passwords three or four times when they create new accounts? In this study, three groups of participants were asked to verify their passwords once (control group), twice, and three times (two experimental groups). Ps…
Tensions of student voice in higher education : Involving students in degree programme curricula design
2020
This paper considers the direct involvement of students in degree programme curricula design, specifically four computer science teacher students designing new curricula for the Faculty of Information Technology of the University of Jyväskylä. They participated in a project to make recommendations for the 2017–2020 master’s and bachelor’s programme curricula. We examined how these recommendations were implemented in the new curricula and what hindered student voice. The project led to major changes: making basic studies in mathematics optional, adding three new courses, and defining new learning goal descriptions for two master’s programmes. Several factors hindered student voice: insuffici…
Oligo(phenylenevinylene)s with reactive side chains: amine- and amide-bound alkoxysilanes
2002
Strongly luminescent oligo(phenylenevinylene) chromophores with monodisperse chain lengths are connected via short spacers containing a secondary amine or amide with di- and tri-ethoxysilane groups. The alkoxysilanes can be hydrolysed and condensed to cyclic and linear oligomers with high film forming capability and are also interesting functional units for hybrid materials for electro-optical applications. The luminescence properties in the solid state are influenced by hydrogen bonding of the amides resulting in strong hypsochromic shifts. The synthesis of the title compounds, their oligomerisation and the electronic spectra in the solution and solid state are presented.
Properties of trialkylamines as catalysts of resoles synthesis
2000
A series of the syntheses of phenol–formaldehyde resoles was carried out in the presence of trimethyl-, triethyl-, tripropyl-, and tributylamines and sodium hydroxide as catalysts for this process. The rate constants were calculated for the partial reactions identified in the synthesis. Also, the performance properties of the resins obtained and the hardened resin samples were estimated in simple tests. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 898–902, 2000
Synthesis of large-pore ordered mesoporous silicas containing aminopropyl groups
2005
Ordered mesoporous silicas with large-pore diameters incorporating aminopropyl groups in variable quantity have been synthesized via the co-condensation of tetraethyl orthosilicate (TEOS) and 3-tert-butyloxycarbonylaminopropyltriethoxysilane templated with nonionic surfactant P123 under acidic conditions. The deprotection of amino groups was then quantitatively achieved either by thermal treatment or acid hydrolysis followed by Et3N treatment, both routes leading to exactly the same materials. We showed that the free amino centers are fully accessible, by using the condensation of the amine function with benzaldehyde.
Association between DRD2/DRD4 interaction and conduct disorder: a potential developmental pathway to alcohol dependence
2013
1 Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil 2 King’s College London, Institute of Psychiatry, MRC Social Genetic and Developmental Psychiatry Centre, London, United Kingdom, UK 3 Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany 4 Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands 5 Psychology Department, National University of Singapore, Singapore, Singapore 6 Department of Psychiatry, Donders Institute for Brain, Cognition an…
Attention-deficit hyperactivity disorder (ADHD), substance use disorders, and criminality: a difficult problem with complex solutions.
2014
Abstract The association between attention-deficit hyperactivity disorder (ADHD) and criminality has been increasingly recognized as an important societal concern. Studies conducted in different settings have revealed high rates of ADHD among adolescent offenders. The risk for criminal behavior among individuals with ADHD is increased when there is psychiatric comorbidity, particularly conduct disorder and substance use disorder. In the present report, it is aimed to systematically review the literature on the epidemiological, neurobiological, and other risk factors contributing to this association, as well as the key aspects of the assessment, diagnosis, and treatment of ADHD among offende…
Self-assembly in surfactant-based liquid mixtures: Octanoic acid/Bis(2-ethylhexyl)amine systems
2012
Abstract The physico-chemical properties of Bis(2-ethylhexyl)amine (BEEA) plus octanoic acid (OA) mixtures have been investigated by IR, SAXS, WAXS, viscosimetry, and AC complex impedance spectroscopy in the whole composition range. Mainly driven by proton transfer from the acidic OA to the basic BEEA, the formation of stoichiometrically well-defined adducts takes place in the mixtures. This causes the slowing down of molecular dynamics and the increase in charge carrier number density. Interestingly, while the pure components possess no significant conductivity (about 10−12 S cm−1 at 25 °C), their mixtures show a composition-dependent enhanced conductivity (up to about 10−5 S cm−1), i.e., …
Liquid Crystalline Orientation of Semiconducting Nanorods in a Semiconducting Matrix
2008
This paper describes the synthesis of narrowly distributed block copolymers consisting of a hole conducting triarylamine block and an anchor block via RAFT polymerization. The anchor block is thereby introduced via a reactive ester approach. Block copolymers with dopamine anchor groups bind to oxidic semiconductors like TiO 2 , SnO 2 , and ZnO. Thus, it becomes possible to cover inorganic electron conducting (acceptor) nanomaterials with a corona of an organic hole conducting (donor) polymer like poly(triphenylamine), giving new hybrid materials. The poly(triphenylamine) grafted to inorganic nanorods allows the preparation of stable nanorod dispersions in appropriate solvents. At higher con…
Melamine induced conformational change of ethyl resorcinarene in solid state
2000
When ethyl resorcinarene (1) and melamine (2) are co-crystallised, all intramolecular hydrogen bonds keeping the resorcinarene in crown conformation are broken causing an unexpected conformational change to boat, and a highly ordered hydrogen bonded network is formed.