Search results for "note"
showing 10 items of 10709 documents
Liquid structure of a choline chloride-water natural deep eutectic solvent: A molecular dynamics characterization
2021
The liquid structure of a representative of the first water-in-salt (WiS) Natural Deep Eutectic Solvents (NADES), hereinafter indicated as aquoline, a mixture of choline chloride (ChCl) and water with molar ratio 1:3.33, is ex- plored at ambient conditions. Using Molecular Dynamics (MD) simulation tools, we extract structural informa- tion at atomistic level on the nature of inter-correlations between the different moieties. Despite being a very fluid liquid, with much lower viscosity than other common ChCl-based DES, aquoline turns out to be very struc- tured. Computed X-ray and neutron weighted scattering patterns (the latter also on selectively deuterated mix- tures) highlight the existe…
Enhancing the luminescence efficiency of silicon-nanocrystals by interaction with H+ions
2018
The emission of silicon nanocrystals (Si-NCs), synthesized by pulsed laser ablation in water, was investigated on varying the pH of the solution. These samples emit μs decaying orange photoluminescence (PL) associated with radiative recombination of quantum-confined excitons. Time-resolved spectra reveal that both the PL intensity and the lifetime increase by a factor of ∼20 when the pH decreases from 10 to 1 thus indicating that the emission quantum efficiency increases by inhibiting nonradiative decay rates. Infrared (IR) absorption and electron paramagnetic resonance (EPR) experiments allow addressing the origin of defects on which the excitons nonradiatively recombine. The linear correl…
Synthesis and self-assembly of a PEGylated-graphene aerogel
2016
Abstract In the frame of this work, we present, for the first time, the synthesis and self-assembly of an aerogel built by graphene oxide-polyethylene glycol. The synthetic route involves at first the coupling of GO with an amino-terminated polyethylene glycol sample by carbodiimide in aqueous environment, and the subsequent conversion of the hydrogel achieved into an aerogel via freeze-drying. The 3D PEGylated graphene-based aerogel, characterized by spectroscopic, morphological, structural and mechanical analyses, displays an ultralight and highly porous (99.7%) network and possesses high mechanical properties together with a good biocompatibility.
Comprensión pública de la nanociencia y la nanotecnología. Informe de los resultados de un estudio Delphi
2013
Según datos de los Eurobarómetros que periódicamente realiza la Comisión Europea y de estudios recientes más específicos, los niveles de cultura científica de la sociedad española se encuentran entre los más bajos de Europa. En el caso de la nanotecnología el desconocimiento es especialmente significativo. El presente informe recoge los principales resultados de una investigación realizada entre expertos sobre comprensión pública de la nanociencia y la nanotecnología. el objetivo del estudio ha sido el de estructurar un conjunto de información básica que pueda ser utilizada para facilitar el acercamiento del conocimiento de la nanociencia y la nanotecnología a la sociedad española y, en tal…
Non-linear optical, electrochemical and spectroelectrochemical properties of amphiphilic inner salt porphyrinic systems
2016
Three zwitterionic meso-substituted A3B- and AB2C-porphyrins containing one sulfonato alkylpyridinium substituent and three or two alkoxy-substituted phenyl groups were synthesized in good yield and fully characterized as to their physicochemical properties by a variety of techniques. This new series of inner salt donor-acceptor meso-substituted porphyrin derivatives were prepared for possible application as amphiphilic probes for membrane insertion in the area of combined second-harmonic and two-photon fluorescence cellular microscopy. To this end, the linear and nonlinear optical properties of the compounds were characterized, together with their electrochemical and spectroelectrochemica…
3-4 gadu vecu bērnu dialoģiskās runas sekmēšana didaktiskajās spēlē
2018
Darba autors: Justīne Druvaskalne Darba vadītājs: Mg. paed. Aija Kalve Darba tēma: 3-4 gadu vecu bērnu diloģiskās runas sekmēšana didaktiskajās spēlēs. Darba veids: Kvalifikācijas darbs Studiju programma: Pirmsskolas izglītības skolotājs Darba apjoms: 43 lpp. Mērķis: Pētīt 3-4 gadu vecu bērna dialoģiskās runas sekmēšanas iespējas didaktiskajās spēlēs. Darba saturs: Pirmjā daļā tiek apkopota informācija par dialoģisko runu, vecumposmu raksturojus, kā arī tiek pētīta literatūra par didaktiskajām spēlēm un kā didaktiskās spēles sekmē bērnu runu. Otrajā daļā tika izvirzīti kritēriji dialoģiskās runas sekmēšanai, kā arī bērni tika novēroti pēc šiem kritērijiem. Tika izstrādāts pedagoģiskais izmē…
Ricerca e Innovazione Responsabili in didattica. Il progetto IRRESISTIBLE
2016
Polytetrafluoroethylene Films in Rigid Polyurethane Foams' Dielectric Permittivity Measurements with a One-Side Access Capacitive Sensor.
2021
As a non-metallic composite material, widely applied in industry, rigid polyurethane (PUR) foams require knowledge of their dielectric properties. In experimental determination of PUR foams’ dielectric properties protection of one-side capacitive sensor’s active area from adverse effects caused by the PUR foams’ test objects has to be ensured. In the given study, the impact of polytetrafluoroethylene (PTFE) films, thickness 0.20 mm and 0.04 mm, in covering or simulated coating the active area of one-side access capacitive sensor’ electrodes on the experimentally determined true dielectric permittivity spectra of rigid PUR foams is estimated. Penetration depth of the low frequency excitation…
DNA-based applications in molecular electronics
2011
This thesis is mainly focused on DNA molecules and especially on self-assembled DNA constructs and their potential applications in nanotechnology and molecular electronics. In the field of molecular electronics the conductivity of DNA is a crucial - yet open - question, and it is of great concern, since DNA is a very promising molecule in a context of bottom-up based nanodevices due to its superior selfassembly characteristics. A key tool in all the experiments presented in this thesis is a dielectrophoretic trapping technique, which was exploited in spatial manipulation of individualDNA molecules, DNA constructs and also semiconducting quantum dots. In the case of DNA, the technique provid…
Baltkrievijas 2020. gada prezidentālās vēlēšanas - atainojums Krievijas medijos
2021
Pētnieciskā darba nosaukums ir: “Baltkrievijas 2020. gada prezidentālās vēlēšanas – atainojums Krievijas mediju dienaskārtībā”. Pētījuma ietvaros izvirzītie mērķi ir sekojoši – 1) izpētīt, kā tika atainotas Baltkrievijas prezidentālās vēlēšanas un ar to saistītie notikumi Krievijas medijos 2020. gada augusta, septembra, oktobra mēnešos; 2) izpētīt Krievijas Federācijas sabiedrības attieksmi par Baltkrievijas prezidentālām vēlēšanām un ar vēlēšanām saistītiem notikumiem. Empīriskie dati pētījumā tika iegūti izmantojot kvalitatīvu kontenta analīzi, sabiedriskās domas aptauju un padziļināto interviju analīzi. Pētījuma rezultātā tika izsecināts, ka Krievijas mediju dienaskārtība ietekmēja Kriev…