Search results for "LUMO"
showing 10 items of 164 documents
Motivational sources of practical nursing students at risk of dropping out from vocational education and training
2019
The aim of this study was to contribute to the understanding of the reasons for low or high academic motivation among practical nursing students at risk of dropping out from vocational education and training. The research data consisted of semi-structured interviews with 14 Finnish students, which were analysed by qualitative content analysis. The analysis identified six motivational sources. Two of these sources – Responsible agency and Completing out of necessity – were related to engagement in studying, whereas two other sources – Exhaustion from learning challenges and Tight-roping between competing responsibilities – were related to disengagement from studying. Emotional drive and Soci…
Synthesis and molecular and electronic structures of a series of Mo3CoSe4 cluster complexes with three different metal electron populations.
2008
The synthesis, crystal structure, and magnetic properties of [Mo 3(CoCO)Se 4(dmpe) 3Cl 3] ( 1), [Mo 3(CoCl)Se 4(dmpe) 3Cl 3] ( 2), and [Mo 3(CoCl)Se 4(dmpe) 3Cl 3](TCNQ) ([ 2](TCNQ)) (dmpe = 1,2-bis(dimethylphosphanyl)ethane; TCNQ = 7,7,8,8-tetracyanoquinomethane) cubane-type complexes with 16, 15, and 14 metal electrons, respectively, are reported. These compounds complete the series of cobalt-containing Mo 3CoQ 4 (Q = S, Se) cubane-type complexes, which allows a complete analysis of the consequences of replacing the inner chalcogen and the metal electron count on the structural, magnetic, and electrochemical properties. The experimental evidence is theoretically supported and rationalized…
The Role of Emission Layer Morphology on the Enhanced Performance of Light-Emitting Diodes Based on Quantum Dot-Semiconducting Polymer Hybrids
2016
The influence of the morphology of quantum dot (QD)-semiconducting polymer hybrid emission layers on the performance of quantum dot-based light emitting diodes (QLEDs) is systematically investigated. Chemically grafted QD-semiconducting polymer hybrids are fabricated by the ligand exchange procedure between CdSe/CdxZn1−xS QDs and a new block copolymer consisting of a carbazole-based electroactive block with a low highest occupied molecular orbital level and a disulfide-based anchor block. The performance of QLEDs with hybrid emission layers is compared with QLEDs utilizing QD-only and physically mixed QD/polymer emission layers. It is shown that only in the emission layers formed by chemica…
Influence of hole transport material ionization energy on the performance of perovskite solar cells
2019
Halide perovskites have shown excellent photophysical properties for solar cell applications which led to a rapid increase of the device efficiency. Understanding the charge carrier dynamics within the active perovskite absorber and at its interfaces will be key to further progress in their development. Here we present a series of fully evaporated devices employing hole transport materials with different ionization energies. The open circuit voltage of the devices, along with their ideality factors, confirm that the former is mainly determined by the bulk and surface recombination in the perovskite, rather than by the energetic offset between the valence band of the perovskite and the highe…
Optimistit opintiellä : opinnoissaan menestyvien nuorten hyvinvointi lukiosta jatko-opintoihin
2007
Sirpa Vahtera tutki väitöstyössään opinnoissaan menestyvien nuorten ajattelu- ja toimintastrategioita ja psyykkistä hyvinvointia lukiosta jatko-opintoihin. - Lukioissa kannattaa vaalia oppimisen ja yhdessä tekemisen iloa. Optimistinen suhtautuminen tulevaisuuteen ja omien tietojen ja taitojen positiivinen arviointi ovat lukiolaisen psyykkistä hyvinvointia varsinkin Suomessa, jossa jatko-opintoihin siirtyminen on monelle nuorelle pitkä ja raskas prosessi, Vahtera kertoo. Vahtera etsi tutkimuksessaan nuorten psyykkistä hyvinvointia ja opiskelua parhaiten tukevia ajattelu- ja toimintatapoja. Opinnoissaan menestyvät nuoret käyttivät optimistista ajattelu- ja toimintastrategiaa. Optimistinen str…
Nonfullerene Polymer Solar Cells Reaching a 9.29% Efficiency Using a BODIPY-Thiophene Backboned Donor Material
2018
A conjugated polymer donor containing BODIPY-thiophene dyads in the backbone, P(BdP-EHT), combined with a low bandgap nonfullerene acceptor (SMDPP) consisting of carbazole and diketopyrrolopyrrole units linked with a tetracyanobutadiene acceptor π-linker, was used to design bulk heterojunction polymer solar cells. After the optimization of the donor to acceptor weight ratio and solvent vapor annealing of the P(BdP-EHT):SMDPP active layer, the resulting polymer solar cell showed an overall power conversion efficiency of 9.29%, which is significantly higher than that for the polymer solar cell based on PC71BM (7.41%) processed under identical conditions. This improved power conversion efficie…
Valokuvatriennaali Lumo 2001 kulttuurituotantona : työryhmän toiminta projektinhallinnan näkökulmasta
2004
Spin state, electronic structure and bonding on C-scorpionate [Fe(II)Cl2(tpm)] catalyst: An experimental and computational study
2020
Abstract The Fe(II) spin state in the condensed phase of [Fe(II)Cl2(tpm)] (tpm = [tris(pyrazol-1-yl)methane]; 1) catalyst has been determined through a combined experimental and theoretical investigation of X-Ray Absorption Spectroscopy (XAS) at the FeL2,3-edges and NK-edge. Results indicated that in this phase a mixed singlet/triplet state is plausible. These results have been compared with the already know Fe singlet spin state of the same complex in water solution. A detailed analysis of the electronic structure and bonding mechanism of the catalyst showed that the preference for the low-spin diamagnetic ground state, strongly depends upon the ligands, the bulk solvent and the interactio…
Tunnetyön kuormittavuus terveydenhuoltoalalla : palvelumotivaatio ja transformationaalinen johtajuus puskuroivina voimavaroina
2015
Tämän pro gradu -tutkielman tavoitteena oli kartoittaa tunnetyön kuormittavuutta suomalaisella terveydenhuoltoalalla. Työn vaatimusten ja voimavarojen mallia (JD-R) hyödyntäen tutkimme, kuinka tunnetyön kuormittavuus työn vaatimustekijänä ja transformationaalinen johtajuus sekä palvelumotivaatio työn voimavaratekijöinä ovat yhteydessä työuupumukseen. Tutkimusaineistoon valikoitui 1450 hoitotyöntekijää, joiden tunnetyön kuormittavuutta (mitattuna emotionaalisella dissonanssilla), palvelumotivaatioita, koettua transformationaalista johtajuutta ja työuupumusta (mitattuna uupumusasteisena väsymyksenä) kartoitettiin kyselylomakkeen avulla. Tutkimushypoteeseina oli, että tunnetyön kuormittavuus o…