538 research outputs found
The relative importance of individual, job-related and organisational characteristics in explaining differences in earnings.
Abstract: This paper focuses on a number of key research questions: (1) What is the relative importance of individual, job-related and organizational characteristics in explaining differences in earnings? (2) Do job characteristics such as hierarchical level and functional domain exercise a significant influence on pay differentials if we control for the traditional human capital factors? (3) Do organizational characteristics such as size and the sector in which the company is active exercise a significant influence on pay differentials if we control for the traditional human capital factors and job-related pay determinants? In order to assess the relative importance of these pay determinants, use is made of linear regression and analysis of variance. The analysis draws on data from the Salary Survey, which generated pay details for a total of more than 15,000 Belgian white-collar workers. Based on the analysis, we come to the conclusion that the five main determinants, in order of importance, are number of years' work experience; level of education; hierarchical level; sector of employment; and the nationality of the parent company. A further striking feature is that more than 50% of the total explained variance can be attributed to the three features which receive a great deal of attention in traditional human capital approaches to pay differentials: level of education, work experience and gender.Implications; Characteristics;
ESR evidence for disordered magnetic phase from ultra-small carbon nanotubes embedded in zeolite nanochannels
A multi-frequency electron spin resonance (ESR) study provides evidence for
the occurrence of low temperature ferromagnetic/spin-glass behavior in aligned
arrays of sub-nanometer single walled carbon nanotubes confined in zeolite
nano-channels, owing to sp2-type non-bonding carbon associated localized states
with density of ~3 x 1019 /g. Features related to the much anticipated
conduction ESR are not detected. In the paramagnetic phase, the ESR linewidth
is found to be weakly dependent on microwave frequency.Comment: Accepted to be published in EuroPhysics Letter
Shape-selective zeolite catalysis for bioplastics production
Biodegradable and renewable polymers, such as polylactic acid, are benign alternatives for petrochemical-based plastics. Current production of polylactic acid via its key building block lactide, the cyclic dimer of lactic acid, is inefficient in terms of energy, time, and feedstock use. We present a direct zeolite-based catalytic process, which converts lactic acid into lactide. The shape-selective properties of zeolites are essential to attain record lactide yields, outperforming those of the current multistep process by avoiding both racemization and side-product formation. The highly productive process is strengthened by facile recovery and practical reactivation of the catalyst, which remains structurally fit during at least six consecutive reactions, and by the ease of solvent and side-product recycling
Cu-ZSM-5: A biomimetic inorganic model for methane oxidation
The present work highlights recent advances in elucidating the methane oxidation mechanism of inorganic Cu-ZSM-5 biomimic and in identifying the reactive intermediates that are involved. Such molecular understanding is important in view of upgrading abundantly available methane, but also to comprehend the working mechanism of genuine Cu-containing oxidation enzymes
Oxygen precursor to the reactive intermediate in methanol synthesis by Cu-ZSM-5
The reactive oxidizing species in the selective oxidation of methane to methanol in oxygen activated Cu-ZSM-5 was recently defined to be a bent mono(ÎŒ-oxo)dicopper(II) species, [Cu_2O]^(2+). In this communication we report the formation of an O_2-precursor of this reactive site with an associated absorption band at 29,000 cm^(-1). Laser excitation into this absorption feature yields a resonance Raman (rR) spectrum characterized by ^(18)O_2 isotope sensitive and insensitive vibrations, ÎœO-O and ÎœCu-Cu, at 736 (Î^(18)O_2 = 41 cm^(-1)) and 269 cm^(-1), respectively. These define the precursor to be a ÎŒ-(η^2:η^2) peroxo dicopper(II) species, [Cu_2(O_2)]^(2+). rR experiments in combination with UV-vis absorption data show that this [Cu_2(O_2)]^(2+) species transforms directly into the [Cu_2O]^(2+) reactive site. Spectator Cu^+ sites in the zeolite ion-exchange sites provide the two electrons required to break the peroxo bond in the precursor. O_2-TPD experiments with ^(18)O_2 show the incorporation of the second ^(18)O atom into the zeolite lattice in the transformation of [Cu_2(O_2)]^(2+) into [Cu_2O]^(2+). This study defines the mechanism of oxo-active site formation in Cu-ZSM-5
Perceived responsiveness in suicidal ideation: An experience sampling study in psychiatric patients
Introduction: Perceived responsiveness, or the extent to which one feels understood, validated and cared for by close others, plays a crucial role in people's wellâbeing. Can this interpersonal process also protect people at risk? We assessed whether fluctuations in suicidal ideation were associated with fluctuations in the degree of perceived responsiveness that psychiatric patients (admitted in the context of suicide or indicating suicidal ideation) experienced in daily interactions immediately after discharge.
Methods: Fiftyâseven patients reported on suicidal ideation (5 times a day) and perceived responsiveness (daily) for four consecutive weeks. The effects of established risk factorsâthwarted belongingness, perceived burdensomeness, and hopelessnessâwere assessed as well.
Results: The more patients felt that close others had been responsive to them, the less suicidal ideation they reported. At low levels of thwarted belongingness, perceived burdensomeness, or hopelessness, perceived responsiveness seemed to play a protective role, negatively coâoccurring with suicidal ideation. When thwarted belongingness, perceived burdensomeness, and hopelessness were high, perceived responsiveness did not have an effect.
Conclusion: Perceived responsiveness could be a protective factor for suicidal ideation for people at risk only when they are experiencing low levels of negative perceptions. When experiencing highly negative perceptions, however, perceived responsiveness seems to matter less
Ligand migration from cluster to support: a crucial factor for catalysis by Thiolate-protected gold clusters
Thiolate
protected
metal
clusters
are valuable
precursors
for the
design
of tailored
nanosized
catalysts.
Their
performance
can
be tuned
precisely
at atomic
level,
e.g. by the configuration/
type
of ligands
or by partial/complete
removal
of the ligand
shell
through
controlled
pre-treatment
steps.
However,
the
interaction
between
the ligand
shell
and
the oxide
support,
as
well
as ligand
removal
by oxidative
pre-treatment,
are
still
poorly
understood.
Typically,
it was
assumed
that
the thiolate
ligands
are simply
converted
into
SO
2
, CO
2
and
H
2
O. Herein,
we
report
the first
detailed
observation
of sulfur
ligand
migration
from
Au to the oxide
support
upon
deposition
and
oxidative
pre-treatment,
employing
mainly
S K-edge
XANES.
Conse-
quently,
thiolate
ligand
migration
not only
produces
clean
Au
cluster
surfaces
but
also
the
surrounding
oxide
support
is
modified
by sulfur-containing
species,
with
pronounced
effects
on catalytic
propertiesPeer ReviewedPostprint (published version
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