60 research outputs found
The Impact of Traumatic Experience on Attitude Towards Future in Refugee Adolescents
Traumatic experience has overall far reaching consequences on personality. In particular,
it has significant impact on teenagers that are just approaching the phase of
solving their identity problems. This research examines the relation of traumatic experience
and attitude towards the future in two groups of adolescents. The first group consists
of 20 adolescents-refugees from the East Slavonia that were settled in Rijeka area
with their parents during the last six years. The second group consists of 20 adolescentâs
local inhabitants that were influenced by the war only indirectly. Results show significant
difference between refugees and non-refugees in expressed interpersonal trust, frustration
tolerance, and formation of close contacts, adaptability, precaution, bitterness,
and social desirability. Both groups show increased depression, pessimism and poor
self-control. This might be considered as general characteristic of society in war
Infrared spectroscopy of small-molecule endofullerenes
Hydrogen is one of the few molecules which has been incarcerated in the
molecular cage of C and forms endohedral supramolecular complex
H@C. In this confinement hydrogen acquires new properties. Its
translational motion becomes quantized and is correlated with its rotations. We
applied infrared spectroscopy to study the dynamics of hydrogen isotopologs
H, D and HD incarcerated in C. The translational and rotational
modes appear as side bands to the hydrogen vibrational mode in the mid infrared
part of the absorption spectrum. Because of the large mass difference of
hydrogen and C and the high symmetry of C the problem is
identical to a problem of a vibrating rotor moving in a three-dimensional
spherical potential. The translational motion within the C cavity breaks
the inversion symmetry and induces optical activity of H. We derive
potential, rotational, vibrational and dipole moment parameters from the
analysis of the infrared absorption spectra. Our results were used to derive
the parameters of a pairwise additive five-dimensional potential energy surface
for H@C. The same parameters were used to predict H energies
inside C[Xu et al., J. Chem. Phys., {\bf 130}, 224306 (2009)]. We
compare the predicted energies and the low temperature infrared absorption
spectra of H@C.Comment: Updated author lis
Information Visualisation for Project Management: Case Study of Bath Formula Student Project
This paper contributes to a better understanding and design of dashboards for monitoring of engineering projects based on the projectsâ digital footprint and user-centered design approach. The paper presents an explicit insight-based framework for the evaluation of dashboard visualisations and compares the performance of two groups of student engineering project managers against the framework: a group with the dashboard visualisations and a group without the dashboard. The results of our exploratory study demonstrate that student project managers who used the dashboard generated more useful information and exhibited more complex reasoning on the project progress, thus informing knowledge of the provision of information to engineers in support of their project understanding
Volatile and thermally stable polymeric tin trifluoroacetates
Tin trifluoroacetates are effective vapor phase single-source precursors for F-doped SnO2, but their structures have been poorly understood for decades. Here we undertook a comprehensive structural analysis of these compounds in both the solid and gas phases through a combined single-crystal X-ray crystallography, gas phase electron diffraction, and density functional theory investigation. Tin(II) bis(trifluoroacetate) (1) thermally decomposes into a 1:1 mixture of 1 and ditin(II) Ό-oxybis(Ό-trifluoroacetate) (2) during sublimation, which then polymerize into hexatin(II)-di-Ό3-oxyoctakis(Ό-trifluoroacetate) (3) upon solidification. Reversible depolymerization occurred readily upon heating, making 3 a useful vapor phase precursor itself. Tin(IV) tetrakis(trifluoroacetate) (5) was also found to be polymeric in the solid state, but it evaporated as a monomer over 130 °C lower than 3. This counterintuitive improvement in volatility by polymerization was possibly due to the large entropy change during sublimation, which offers a strategic new design feature for vapor phase deposition precursors
Atomic Layer Deposition of PbS Thin Films at Low Temperatures
doi: 10.1021/acs.chemmater.0c01887Atomic layer deposition (ALD) is a viable method for depositing functional, passivating, and encapsulating layers on top of halide perovskites. Studies in that area have only focused on metal oxides, despite a great number of materials that can be made with ALD. This work demonstrates that, in addition to oxides, other ALD processes can be compatible with the perovskites. We describe two new ALD processes for lead sulfide. These processes operate at low deposition temperatures (45-155 degrees C) that have been inaccessible to previous ALD PbS processes. Our processes rely on volatile and reactive lead precursors Pb(dbda) (dbda = rac-N-2,N-3-di-tertbutylbutane-2,3-diamide) and Pb(btsa)(2) (btsa = bis(trimethylsilyl)amide) as well as H2S. These precursors produce high quality PbS thin films that are uniform, crystalline, and pure. The films exhibit p- type conductivity and good mobilities of 10-70 cm(2) V-1 s(-1). Low deposition temperatures enable direct ALD of PbS onto a halide perovskite CH3NH3PbI3 (MAPI) without its decomposition. The stability of MAPI in ambient air is greatly improved by capping with ALD PbS. More generally, these new processes offer valuable alternatives for PbS-based devices, and we hope that this study will inspire more studies on ALD of non-oxides on halide perovskites.Peer reviewe
Dynamics of a stochastic excitable system with slowly adapting feedback
We study an excitable active rotator with slowly adapting nonlinear feedback
and noise. Depending on the adaptation and the noise level, this system may
display noise-induced spiking, noise-perturbed oscillations, or stochastic
busting. We show how the system exhibits transitions between these dynamical
regimes, as well as how one can enhance or suppress the coherence resonance, or
effectively control the features of the stochastic bursting. The setup can be
considered as a paradigmatic model for a neuron with a slow recovery variable
or, more generally, as an excitable system under the influence of a nonlinear
control mechanism. We employ a multiple timescale approach that combines the
classical adiabatic elimination with averaging of rapid oscillations and
stochastic averaging of noise-induced fluctuations by a corresponding
stationary Fokker-Planck equation. This allows us to perform a numerical
bifurcation analysis of a reduced slow system and to determine the parameter
regions associated with different types of dynamics. In particular, we
demonstrate the existence of a region of bistability, where the noise-induced
switching between a stationary and an oscillatory regime gives rise to
stochastic bursting
Foliar epidermis morphology in Quercus (subgenus Quercus, section Quercus) in Iran
The foliar morphology of trichomes, epicuticular waxes and stomata in Quercus cedrorum, Q. infectoria subsp. boissieri, Q. komarovii, Q. longipes, Q. macranthera, Q. petraea subsp. iberica and Q. robur subsp. pedunculiflora were studied by scanning electron microscopy. The trichomes are mainly present on abaxial leaf surface in most species, but rarely they appear on adaxial surface. Five trichome types are identified as simple uniseriate, bulbous, solitary, fasciculate and stellate. The stomata of all studied species are of the anomocytic type, raised on the epidermis. The stomata rim may or may not be covered with epicuticular. The epicuticular waxes are mostly of the crystalloid type but smooth layer wax is observed in Q. robur subsp. pedunculiflora. Statistical analysis revealed foliar micromorphological features as been diagnostic characters in Quercus
Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic
This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
Formation of coherent rotational wavepackets in small molecule-helium clusters using impulsive alignment
Length and width of guard cells and variation in the appearance of stomata pores in some species of genus Arum from the Eastern Slavonia and Baranya Region
Length and width of guard cells and variation in the appearance of stomata pores in the following Arum species: Arum italicum Mill., Arum maculatum var. maculatum L. and Arum maculatum var. immaculatum L. at ZablaÄe and Normanci location, and Arum alpinum var. pannonicum Terpo., Arum alpinum var. intermedium Schur. in Bilje at the eastern Slavonia and Baranya region were investigated. With regard to guard cells length and width and variation in the appearance of stomata pores, stomata of certain Arum species are considered to be of larger dimensions (âŻ38 ”m). Arum species grown at ZablaÄe had the longest and widest guard cells as well as the greatest variation in the appearance of stomata pores, followed by those at Normanci, whereas species at Bilje location had the lowest values. The average length and width of the guard cells and variation in the appearance of stomata pores were larger at the lower than at the upper epidermis among each examined Arum species at each location. A significant difference in guard cells length and width and variation in the appearance of stomata pores at both upper and lower epidermis was determined for ZablaÄe and Normanci location, whereas there was no significant difference in those parameters at Bilje location
- âŠ