Search results for "trap"
showing 10 items of 2144 documents
Space Charge and Carrier Trapping Effects on the Transient Photocurrents of Organic Materials Using the Time-of-Flight Technique
2007
We apply the time-of-flight (TOF) technique to study space charge and carrier trapping effects in the organic materials N,N'-diphenyl-N,N'-bis(3- methylphenyl)-1,1-biphenyl-4,4'-diamine (TPD) and tris(8-hydroxyquinolato) aluminum (Alq3). This is carried out by changing the applied electric field, the laser pulse intensity, and the repetition rate together with environmental conditions in air or in vacuum. We report for the first time, to the best of our knowledge, a clearly nondispersive electron transport in TPD due to the absence of deep traps. Conversely, Alq3 exhibits a dispersive electron transport. However, this can be partially recovered by leaving the sample in high vacuum for sever…
Electron correlation effects on the calculated 13C NMR spectra of vinyl cations
1997
Abstract A study of calculated 13C NMR chemical shifts in vinyl cations is presented. The sensitivity of predicted isotropic shifts to correlation, basis set and geometry effects is explored. In order to obtain accurate estimates that are reasonably well converged with respect to further improvements in theory, it appears that the CCSD(T) method must be used with a basis of triple-zeta plus polarization quality on the carbon atoms. Second-order many-body perturbation theory performs adequately for all carbons except for that bearing the formal positive charge, while the self-consistent field approximation cannot be relied upon to predict even the correct qualitative ordering in the spectrum…
Carbon nanotubes as electrodes for dielectrophoresis of DNA
2006
Dielectrophoresis can potentially be used as an efficient trapping tool in the fabrication of molecular devices. For nanoscale objects, however, the Brownian motion poses a challenge. We show that the use of carbon nanotube electrodes makes it possible to apply relatively low trapping voltages and still achieve high enough field gradients for trapping nanoscale objects, e.g., single molecules. We compare the efficiency and other characteristics of dielectrophoresis between carbon nanotube electrodes and lithographically fabricated metallic electrodes, in the case of trapping nanoscale DNA molecules. The results are analyzed using finite element method simulations and reveal information abou…
Dielectrophoretic trapping of DNA origami.
2008
In this thesis three-dimensional tube-shaped DNA-origamis were dielectrophoretically trapped within lithographically fabricated nanoelectrodes. The origamis had been premade while the electrodes were fabricated specifically for these experiments with two different gapsizes, 150 nm and 400 nm. The aim of the work was to capture individual nanotubes in the gap between the electrodes by utilizing the dielectrophoretic forces present in the structure when a solution containing the origamis was put onto the electrodes and a voltage was applied. It was observed during the experiments that the success of the dielectrophoretic trapping depended strongly on the trapping conditions. This caused the t…
Study of the Fragmentation of D-Glucose and Alkylmonoglycosides in the Presence of Sodium Ions in an Ion-Trap Mass Spectrometer
2009
Abstract Using electrospray ion-trap mass spectrometry, the fragmentation of D-glucose and alkylmonoglycopyranosides (alkyl-GPs) was studied. In the presence of Na+, B1 and 0,2A fragmentations were observed. The alkyl-GPs also showed a 2,5Afragmentation. A cluster containing no carbon atoms and adducts of this cluster with neutral molecules were observed. Standards of alkylmonoglycofuranosides (alkyl-GFs) were not available; however, their fragmentation was studied by high-performace liquid chromatography–mass spectrometry (HPLC-MS) and HPLC-MS2 using an industrial mixture of alkylpolyglycosides. The cluster and its adducts were more easily formed by the alkyl-GPs than by the alkyl-GFs, but…
Fragmentations and reactions of some isotopically labelled dimethyl methyl phosphono and trimethyl phosphoro thiolates and thionates studied by elect…
2005
In this paper, studies on electrospray ionisation ion trap mass spectrometry of organophosphates are extended to a series of dimethyl methylphosphono and trimethyl phosphoro thionates and thiolates and some deuterated isotopomers. Of particular, interest is the comparison of the collision-induced fragmentation of ions from these compounds with those of the non-sulphur containing analogues reported previously. The thiono and thiolo isomeric structures of the sulphur containing ions analogous to I and II (see below) have very similar energies and undergo a ready interconversion. In the case of the phosphono compounds, the electronic structure calculations show that the methyl migration implic…
Nanoelectrospray with ion-trap mass spectrometry for the determination of beta-casomorphins in derived milk products.
2009
Beta-casomorphins (b-CMs) are bioactive peptides derived from casein with opioid agonist effects similar to morphine. The use of electrospray (ESI) with quadrupole ion-trap mass spectrometry (QIT-MS) for these compounds in two matrices, cheese and milk, was examined. It was compared to a liquid chromatography (LC) coupled to mass spectrometry (LC-MS), and a "soft" ionisation technique, NanoMate, with selected ion monitoring (SIM), which are unreliable for the determination of trace casomorphins in derived milk products. b-CM mass fragmentation pathways were done for the four most common b-CMs: beta-casomorphin (1-5) bovine (b-CM-5), beta-casomorphin (1-7) bovine (b-CM-7), [D-Ala2, D-Pro4,Ty…
Musiikki katsojan odotuksia muovaavana tekijänä Michael Haneken elokuvassa Funny Games (1997)
2016
Tämän tutkimuksen tarkoituksena oli tarkastella musiikin vaikutusta katsojan tulkintaan ja odotusten syntymiseen elokuvan Funny Games (1997) avauskohtauksen kautta. Kohtauksessa soiva musiikki on nähty kuvastavan elokuvan yleistä tunnelmaa ja juonta erittäin hyvin ja tämän vuoksi musiikin on nähty viestivän katsojalle sisällöltään epämukavasta elokuvasta. Tutkimusta varten haastateltiin yhteensä kolmea yliopisto-opiskelijaa, jotka katsoivat lyhyen ja pitkän version kohtauksesta ja sen pohjalta kertoivat näkemyksistään elokuvan jatkosta ja kohtauksen sisällöstä. Haastatteluaineisto analysoitiin teoriaohjaavan sisällönanalyysin keinoin. Tulosten myötä kävi ilmi, että musiikilla on merkitystä …
Structural Source of the Trap of ICT Advancement - Lessons from World ICT Top Leaders
2014
In light of the significant consequence of the trap of dramatic advancement of information and communication technology (ICT) in the global economy, both nations and firms that have been compelling their productivity decline. This resulted in great stagnation of ICT advanced economies and therefore its structural sources were analyzed. Based on an empirical analysis tracing, the trend in marginal productivity of ICT and its subsequent prices among the top ICT leaders in the world over the last two decades correlating with the effects of ICT, two faces of ICT advancement were identified. On one side, advancement of ICT contributes to its prices increase by new functionality development, its …
Productivity of wastewater treatment plants in the Valencia Region of Spain
2017
Abstract This study analyses the evolution of productivity over the 2008–2012 period for a homogenous set of 199 wastewater treatment plants that are located in the Valencia Region of Spain and utilize the same treatment technology, using the smoothed bootstrap Malmquist productivity index based on Data Envelopment Analysis (DEA). The results reveal a negative trend in productivity that is mainly the result of resource management rather than an inappropriate level of innovation or use of new technologies. In addition, the effect of exogenous factors on productivity is analysed using the Kruskal-Wallis (KW) test, finding that productivity levels were affected by the quality of the influent w…