16 research outputs found
Evaluating University-Business Collaboration at Science Parks: a Business Perspective
The evaluation of the companies’ performance at University Science Parks (SPs) becomes essential in identifying the needs of the companies and the feasibility of the University-Business Collaboration (ubc). The companies’ real needs are also of interest for universities and SPs, since they face the challenge of designing strategies that best help them to transfer knowledge more effectively. This research article focuses on Key Performance Indicators (kpis) in ubc, needs and business objectives of companies co-located at SPs in Spain and Mexico. This article (i) aims to identify the kpis in ubc used by co-located companies at SPs, and (ii) explore the kpis in ubc and critical success factors of SPs. This article focuses on the perspective of companies, with a secondary focus on the perspectives of SPs and universities. For this study, data was collected through online company surveys in Spain and Mexico.Postprint (published version
Operando NAP-XPS studies of a ceria-supported Pd catalyst for CO oxidation
Supported Pd/CeO2 catalytic systems have been widely investigated in the low-temperature oxidation of CO (LTO CO) due to the unique oxygen storage capacity and redox properties of the ceria support, which highly influence the structural, chemical and electronic state of Pd species. Herein, operando near-ambient pressure XPS (NAP-XPS) technique has allowed the study of a conventional Pd/CeO2 catalyst surface during the CO oxidation reaction under experimental conditions closer to the actual catalytic reaction, unfeasible with other surface science techniques that demand UHV conditions. SEM, HRTEM and XRD analyses of the powder catalyst, prepared by conventional incipient wetness impregnation, reveal uniformly CeO2-loaded Pd NPs of less than 2 nm size, which generated an increase in oxygen vacancies with concomitant ceria reduction, as indicated by H2-TPR and Raman measurements. Adsorbed peroxide (O22-) species on the catalyst surface could also be detected by Raman spectra. Operando NAP-XPS results obtained at the ALBA Synchrotron Light Source revealed two kinds of Pd species under reaction conditions, namely PdOx and PdII ions in a PdxCe1-xO2-d solution, the latter one appearing to be crucial for the CO oxidation. By means of a non-destructive depth profile analysis using variable synchrotron excitation energies, the location and the role of these palladium species in the CO oxidation reaction could be clarified: PdOx was found to prevail on the upper surface layers of the metallic Pd supported NPs under CO, while under reaction mixture it was rapidly depleted from the surface, leaving a greater amount in the subsurface layers (7% vs. 12%, respectively). On the contrary, the PdxCe1-xO2-d phase, which was created at the Pd–CeO2 interface in contact with the gas environment, appeared to be predominant on the surface of the catalyst. Its presence was crucial for CO oxidation evolution, acting as a route through which active oxygen species could be transferred from ceria to Pd species for CO oxidation.Peer ReviewedPostprint (published version
Enhanced hydrothermal resistance of Y-TZP ceramics through colloidal processing
Two commercial zirconia powders with 3 mol% of yttria
(TZ3YE and TZ3YS, labeled as ZE and ZS, respectively) sup-
plied by Tosoh (Japan) were used for this study. Maximum
colloidal stability for ZE was achieved by dispersing the pow-
ders in a mixture of water/ethanol of 90:10 (wt/wt) using a
sonication probe. The rheological behavior of the suspensions
was optimized in terms of solids content ranging from 20 to
33 vol% and sonication time (0
–
6 min), the best results being
obtained after 2 min. ZS samples were prepared to a solids
loading of 30 vol% in water dispersing with 2 min-sonication.
Samples obtained by slip casting in plaster molds were used for
dynamic sintering studies, and fully dense and nanostructured
specimens were obtained at temperatures of 1300
°
C
–
1350
°
C
(ZE samples) and 1400
°
C per 2 h (ZS samples). The Hardness
(
H
) and Young’s Modulus (
E
) properties of the specimens were
studied by nanoindentation technique giving 17 and 250 GPa
mean values for
H
and
E
, respectively. The specimens were
then forced to a low-temperature degradation (LTD) treatment
at 130
°
C for 240 h in steps of 60 h. Raman spectroscopy and
nanoindentation results of hydrothermally treated samples
showed the absence of transformation from tetragonal to
monoclinic phase until 180 h whereas the mechanical properties
maintained constant even at the sample surface. After 240 h of
LTD, the monoclinic phase was detected on all specimens by
Raman peaks centered at 180, 191, and 383 cm
1
. The nanoin-
dentation study revealed an important loss of mechanical fea-
tures reaching 10 and 175 GPa for
H
and
E
, respectively. In
the case of the ZS specimens, no monoclinic phase is detected
after 240 h of LTD treatment and no decay of
E
or
H
is
detected. The free defect microstructure reached for the ZS
specimen revealed a higher hydrothermal resistance so that it is
concluded that the excellent behavior against thermal degrada-
tion is possible due to the large uniformity obtained by colloi-
dal processing rather than the particle size of the starting
powdersPeer Reviewe
Nectar antimicrobial compounds and their potential effects on pollinators
Nectar is a sugary, aqueous solution that plants offer as a reward to animal mutualists for visitation. Since nectars are so nutrient-rich, they often harbor significant microbial communities, which can be pathogenic, benign, or even sometimes beneficial to plant fitness. Through recent advances, it is now clear that these microbes alter nectar chemistry, which in turn influences mutualist behavior (e.g. pollinator visitation). To counteract unwanted microbial growth, nectars often contain antimicrobial compounds, especially in the form of proteins, specialized (secondary) metabolites, and metals. This review covers our current understanding of nectar antimicrobials, as well as their interplay with both microbes and insect visitors