572 research outputs found
Organic mulches as an alternative to conventional under-vine weed management in Mediterranean irrigated vineyards
Vineyard growth and grape yield can be significantly reduced by weeds, especially when
these are located in the under-vine zone. Traditional weed management consists of recurrent tillage,
which is associated with soil erosion and high fuel consumption, or herbicide applications, associated
with damage to the environment and human health. In order to find alternative weed management
methods, three field trials were carried out in Raimat (Lleida, NE Spain) with the aim of evaluating the
suppressive effect of four mulches against weeds. Treatments included (1) straw mulch of Medicago
sativa L., (2) straw mulch of Festuca arundinacea (L.) Schreb, (3) straw mulch of Hordeum vulgare L.,
(4) chopped pine wood mulch of Pinus sylvestris L., (5) mechanical cultivation and (6) herbicide
application. The results showed that all mulches were efficient at controlling weeds (<20% of weed
coverage) in the first year, compared with the two traditional methods, as long as the percentage of
soil covered by mulches was high (>75%). In this way, pine mulch stood out above the straw mulches,
as it achieved high soil cover during the three growing seasons of the study (>80%), with weed
coverage values under 18%. This, together with the multiple benefits of mulches (improvements in
the water balance and increases in soil organic matter, among others), make them a sustainable tool
to be considered as an alternative to traditional under-vine weed management in vineyards.This work has been supported by the Spanish State Research Agency (AEI) and the European Regional Development Fund (ERDF) through the project AGL2017-83325-C4-2-R, and also by MACMHER "Grups Operatius" promoted by the Department of Agriculture of the Catalan Government (DARP) in 2018. The first author obtained a PhD grant from the University of Lleida (PhD grants)
Device Performance of Emerging Photovoltaic Materials (Version 2)
Following the 1st release of the “Emerging photovoltaic (PV) reports”, the best achievements in the performance of emerging photovoltaic devices in diverse emerging photovoltaic research subjects are summarized, as reported in peer-reviewed articles in academic journals since August 2020. Updated graphs, tables, and analyses are provided with several performance parameters, e.g., power conversion efficiency, open-circuit voltage, short-circuit current density, fill factor, light utilization efficiency, and stability test energy yield. These parameters are presented as a function of the photovoltaic bandgap energy and the average visible transmittance for each technology and application and are put into perspective using, e.g., the detailed balance efficiency limit. The 2nd instalment of the “Emerging PV reports” extends the scope toward tandem solar cells and presents the current state-of-the-art in tandem solar cell performance for various material combinations
Deformation heterogeneity study of a 6061-T6 aluminum alloy processed by equal channel angular pressing
Among the severe plastic deformation techniques, the equal channel angular pressing
(ECAP) has drastically improved the mechanical properties of the processed alloys. However,
information regarding friction phenomenon, which modifies the deformation at the surface and the
heterogeneity microstrain state produced by the process itself, is still scarce. In the present work, the
deformation heterogeneity and the friction effect, at the surface in the bulk material of the 6061-T6
aluminum alloy processed by ECAP, is presented and discussed. The residual stress (RS)
measurements were performed by means of X-Ray diffraction. By means of synchrotron diffraction,
volumetric sections of the ECAPed samples were characterized. Finite element analysis showed a
good agreement with the experimentally obtained residual stress and microhardness mapping
results. The study also showed that the highest deformation zones were located at the outer parts of
the deformed samples (top and bottom), while the inner zone showed strain oscillations of up to
49±2 MPa.Peer ReviewedPostprint (author's final draft
On the uptake of cationic liposomes by cells: from changes in elasticity to internalization
In this study, we assessed the capacity of a previously reported engineered liposomal formulation, which had been tested against model membranes mimicking the lipid composition of the HeLa plasma membrane, to fuse and function as a nanocarrier in cells. We used atomic force microscopy to observe physicochemical changes on the cell surface and confocal microscopy to determine how the liposomes interact with cell membranes and released their load. In addition, we performed viability assays using methotrexate as an active drug to obtain proof of concept of the formulation´s capacity to function as a drug delivery-system. The interaction of engineered liposomes with living cells corroborates the information obtained using model membranes and supports the capacity of the engineered liposomal formulation to serve as a potential nanocarrier
Proyecto de consolidación y mejora urbano-rural en Pinares de Oriente, Medellín
La presente memoria ha sido elaborada entre julio y agosto de 2017 gracias al trabajo conjunto realizado entre estudiantes y profesores de la Universitat Politècnica de Catalunya y la Universidad Nacional de Colombia. Este proyecto de urbanización, reparcelación y estabilización del barrio de Pinares de Oriente se enmarca dentro de una campaña para el mejoramiento integral de barrios [MIB] que abarca aspectos no sólo de carácter físico-espacial sino también social, económico, educativo, ambiental y cultural.Postprint (published version
Surface Analysis of 4-Aminothiophenol Adsorption at Polycrystalline Platinum Electrodes
Formation of self-assembled monolayer (SAM) of 4-aminothiophenol (4-ATP) on polycrystalline platinum electrodes has been studied by surface analysis and electrochemistry techniques. The 4-ATP monolayer was characterized by cyclic voltammetry (CV), Raman spectroscopy, reflection absorption infrared (RAIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry (CV) experiments give an idea about the packing quality of the monolayer. RAIR and Raman spectra for 4-ATP modified platinum electrodes showed the characteristic adsorption bands for neat 4-ATP indicating the adsorption of 4-ATP molecules on platinum surface. The adsorption on platinum was also evidenced by the presence of sulfur and nitrogen peaks by XPS survey spectra of the modified platinum electrodes. High resolution XPS studies and RAIR spectrum for platinum electrodes modified with 4-ATP indicate that molecules are sulfur-bonded to the platinum surface. The formation of S-Pt bond suggests that ATP adsorption gives up an amino terminated SAM. Thickness of the monolayer was evaluated via angle-resolved XPS (AR-XPS) analyses. Derivatization of 4-ATP SAM was performed using 16-Br hexadecanoic acid
Galaxy clusters and groups in the ALHAMBRA Survey
We present a catalogue of 348 galaxy clusters and groups with
selected in the 2.78 ALHAMBRA Survey. The high precision of our
photometric redshifts, close to , and the wide spread of the seven
ALHAMBRA pointings ensure that this catalogue has better mass sensitivity and
is less affected by cosmic variance than comparable samples.
The detection has been carried out with the Bayesian Cluster Finder (BCF),
whose performance has been checked in ALHAMBRA-like light-cone mock catalogues.
Great care has been taken to ensure that the observable properties of the mocks
photometry accurately correspond to those of real catalogues. From our
simulations, we expect to detect galaxy clusters and groups with both
completeness and purity down to dark matter halo masses of
for . Cluster redshifts are
expected to be recovered with precision for . We also expect
to measure cluster masses with
precision down to , masses which are
smaller than those reached by similar work.
We have compared these detections with previous optical, spectroscopic and
X-rays work, finding an excellent agreement with the rates reported from the
simulations. We have also explored the overall properties of these detections
such as the presence of a colour-magnitude relation, the evolution of the
photometric blue fraction and the clustering of these sources in the different
ALHAMBRA fields. Despite the small numbers, we observe tentative evidence that,
for a fixed stellar mass, the environment is playing a crucial role at lower
redshifts (z0.5).Comment: Accepted for publication in MNRAS. Catalogues and figures available
online and under the following link:
http://bascaso.net46.net/ALHAMBRA_clusters.htm
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