375 research outputs found
Bond behavior of fiber reinforced polymer bars under direct pullout conditions
This paper examines the behavior of Eurocrete fiber-reinforced polymer (FRP) bars (glass, carbon, aramid, and hybrid) in concrete under direct pullout conditions. More than 130 cube specimens were tested in direct pullout where no splitting was allowed to develop. In normal concrete, the mode of bond failure of FRP bars was found to differ substantially from that of deformed steel bars because of damage to the resin rich surface of the bar when pullout takes place. Bond strengths developed by carbon fiber-reinforced polymer and glass fiber-reinforced polymer bars appear to be very similar and just below what is expected from deformed steel bars under similar experimental conditions. The load slip curves highlight some of the fundamental differences between steel and FRP materials. This paper reports in detail on the influence of various parameters that affect bond strength and development such as the embedment length, type, shape, surface characteristics, and diameter of the bar as well as concrete strength. The testing arrangement is also shown to influence bond strength because of the âwedging effectâ of the bars
Word-level Symbolic Trajectory Evaluation
Symbolic trajectory evaluation (STE) is a model checking technique that has
been successfully used to verify industrial designs. Existing implementations
of STE, however, reason at the level of bits, allowing signals to take values
in {0, 1, X}. This limits the amount of abstraction that can be achieved, and
presents inherent limitations to scaling. The main contribution of this paper
is to show how much more abstract lattices can be derived automatically from
RTL descriptions, and how a model checker for the general theory of STE
instantiated with such abstract lattices can be implemented in practice. This
gives us the first practical word-level STE engine, called STEWord. Experiments
on a set of designs similar to those used in industry show that STEWord scales
better than word-level BMC and also bit-level STE.Comment: 19 pages, 3 figures, 2 tables, full version of paper in International
Conference on Computer-Aided Verification (CAV) 201
The dysbindin-containing complex (BLOC-1) in brain: developmental regulation, interaction with SNARE proteins and role in neurite outgrowth.
Previous studies have implicated DTNBP1 as a schizophrenia susceptibility gene and its encoded protein, dysbindin, as a potential regulator of synaptic vesicle physiology. In this study, we found that endogenous levels of the dysbindin protein in the mouse brain are developmentally regulated, with higher levels observed during embryonic and early postnatal ages than in young adulthood. We obtained biochemical evidence indicating that the bulk of dysbindin from brain exists as a stable component of biogenesis of lysosome-related organelles complex-1 (BLOC-1), a multi-subunit protein complex involved in intracellular membrane trafficking and organelle biogenesis. Selective biochemical interaction between brain BLOC-1 and a few members of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) superfamily of proteins that control membrane fusion, including SNAP-25 and syntaxin 13, was demonstrated. Furthermore, primary hippocampal neurons deficient in BLOC-1 displayed neurite outgrowth defects. Taken together, these observations suggest a novel role for the dysbindin-containing complex, BLOC-1, in neurodevelopment, and provide a framework for considering potential effects of allelic variants in DTNBP1--or in other genes encoding BLOC-1 subunits--in the context of the developmental model of schizophrenia pathogenesis
Key factors controlling the post-fire hydrological and erosive response at micro-plot scale in a recently burned Mediterranean forest
The impacts of wildfires on the hydrological and erosive response of forest ecosystems have been extensively
studied worldwide. Nevertheless, few studies have measured post-fire runoff and erosion over large time scales
in Mediterranean-climate type environments and even fewer studies considered the effects of pre-fire land
management practices on post-fire hydrological and erosive processes. In a previous study in the Colmeal
study area, Vieira et al. (2016) revealed that post-fire runoff and erosion may not follow the classic window of
disturbance model, since the peak of post-fire response occurred in the second and third years after fire. This previous study also showed that pre-fire land management can substantially influence the post-fire response, since
annual runoff and erosion were lower in pre-fire unplowed than plowed sites. In this follow-up work, a multiple
regression model (MRM) analysis was performed to understand how several key factors influence the hydrological and erosive response of a burned Mediterranean forest, taking into account the wildfire; pre-fire land
management practices (unplowed, downslope plowed, and contour plowed) and soil moisture conditions.
Based on the results of the present study, post-fire runoff was largely explained by rainfall amounts and soil water
repellency (SWR)-related variables, whereas erosion processes were better explained by rainfall intensity and
ground cover variables. Fewer factors were found to control the hydrological response of plowed sites when compared to the unplowed site. Aside from rainfall intensity, which was the major factor controlling sediment losses,
bare soil cover also seems to have been important for erosion processes at the unplowed site, whereas at the
plowed sites stone cover was the second most relevant factor. Rainfall-related variables (rainfall and maximum
30-min rainfall intensity) were more important for explaining runoff and erosion under dry conditions than
under wet conditions. The results of the MRM analysis are an important contribution to understand the dynamics
of burned forest areas and should be considered when adapting hydrological and erosion models to post-fire
environments.publishe
Los términos "bonum ordinis" y la "bonum moris" y la noción de moralidad estudio en Santo Tomås
This study constitutes a contribution to the metaphysical fundamentation of
the moral order.
The chapter dealing with «The Notion of Creation and the Metaphysical Situation
of Created Beingo lays down the metaphysical basis for the study of
the terms bonum ordinis -good of order- and bonum moris -moral good.
The chapter on «The Causeof the Order in the Universeo offers the point of
departure for passing away from the object of Metaphysics towards that of
Morals. It is interesting to find out what constitutes the cause of the order
found in the Universe and which can be captured in a first appreciation of
reality as being multiple and ordained: a unit of order which calls for an
investigation of its cause and a reduction of its real multiplicity to the unit
level. From this, there derives the necessity of distinguishing between the predicamental
and transcendental levels, and al so the introduction of the concept
of participation and of its logical vision, the analogia entis.
In this manner, we reach the problem of Being and of beings, of transcendental
causality and of the presence of Being in the nature of beings -« The Founding
Presence of Godo. From the fullness of perfection found in God as Pure Act of
Being, we can deduce explicit notions of the being and manner of operating
of God which are present in all posterior developments of the present work,
for example, good of order, divine government, etc. By this way only is it
possible for us to give the notion of morality a sound and sol id metaphysical
basis.
The chapter devoted to .God and the Created Universe» permits us to
affirm that the formal constitutive element of morality is to be found in the
ordaining or relating of human acts towards man's ultimate end. Now, morality
is to be found to be metaphysical because of its formal object, insofar as
it studies an aspect of the being as such, the good, which entails an ordination
towards that end -«Being and Perfection»- which constitutes the bonum
ordinis. For this reason, the passing from being as such to being as good,
and of the ordo rerum to ordo ad bonum, has a real metaphysical basis. The
ordo ad bonum is, as a consequence, ordinatio in Deum as a result of creation.
The ordinatio in finem is a necessary relation found in creatures and
in the divine creative action -given the free wll of God to create. It is based
upon the esse and has for its subject the supposed subsistent. It is an esse
a Deo and ad Deum, since the Final Cause is the very first of all causes.
The Final Cause -the ultimate end- is the principie of all order, including
the moral order. This is so because God gave their being to all creatures
with order, according to the plan sketched out in His Divine Providence -eternal
law- and conducts them towards their end through the execution of
His plan -divine government- and wanted to count with the rational creature,
making him partial to the eternal law and to the divine government in a
different manner than that of irrational creatures. The moral natural law is
that participation of the eternal law in man which can be known by way of
natural reason and which can be wished by free will. In this manner, man
participates in the divine government and is capable of governing himself as
well as others, of carrying out the divine order wished by God, wanting what
God Himself wants and in the same manner in which He wants it. He can
give to the good of order a new dimension: the moral dimensiono The first
basis, therefore, of the moral order is Godo The objective basis of morality is
the ordaining of everything to Godo But its subjective basis is created freedom:
thanks to it, man is capable of ordaining himself, on his own, to Godo
The ordaining to God is a good, a participation in the eternal law which
in man acquires a moral dimension, the moral goodo The moral order is the
divine order found in the rational creatureo
The moral law is universal, objective, immutable and inherent to man:
it has been given to him in agreement with his own nature, with his proper
mode of being -rational being- and his own mode of being ordained to
Godo And, as a consequence, man's freedom is not the cause of his ordaining
to God, nor its measure, but rather is created according to the eternal
law of Godo
To say that the constitutive element of morality is to be found in the
good of order is to refer to to good of order in man, because the constitutive
element or essence of morality is rather to be found in that relation,
ordinance, or proportion of human acts with regard to the endo This relation
towards the end -that is, towards God- is a necessary accident, consequent
to the divine creative actiono In human acts, however, that accident
is put forth as a determination of the operation, as an intention of the end,
or as an identification with the plan of Godo In order for that to happen
-for man to attain through his own acts the fullness of goodness to which
he is ordained- integrity is necessary in the three principies which are present
in the mora lit y of all human acts: the object, the end, and the circumstances
Causal Modeling of Soil Processes for Improved Generalization
Measuring and monitoring soil organic carbon is critical for agricultural productivity and for addressing critical environmental problems. Soil organic carbon not only enriches nutrition in soil, but also has a gamut of co-benefits such as improving water storage and limiting physical erosion. Despite a litany of work in soil organic carbon estimation, current approaches do not generalize well across soil conditions and management practices. We empirically show that explicit modeling of cause and-effect relationships among the soil processes improves the out-of-distribution generalizability of prediction models. We provide a comparative analysis of soil organic carbon estimation models where the skeleton is estimated using causal discovery methods. Our framework provide an average improvement of 81% in test mean squared error and 52% in test mean absolute error
The effects of wildfire frequency on post-fire soil surface water dynamics
Increasing wildfire frequency in the Mediterranean Basin could affect future plant-soilâwater-dynamics. The capacity of soils to retain water is a key parameter affecting plant post-fire regeneration. Yet, few research has looked at how different soil properties related to water retention is affected by increasing wildfire frequency. This study aimed at understanding the relationship between wildfire frequency, soilâwater-related properties and the dynamics of surface water in soils. To this, after a 2012-summer wildfire in Portugal, three sets of three replicate maritime pine stands with contrasted wildfire frequency were selected (0 vs. 1 vs. 4 fires since 1975). At each of the nine study sites, three re-sprouter shrubs and neighbouring bare soil were chosen (54 microsites). There, soil cover, soilâwater retention curves and surface (0â5 cm) soilâwater-related properties (texture, bulk density, organic matter content, soil moisture, soil surface water repellency) were monitored for one year. Furthermore, records of post-fire soil moisture dynamics were analysed continuously using 72 probes installed at 2.5 and 7.5 cm depth. The hillslopes affected by 1 fire showed higher plant recovery than the 4 fires hillslopes. During the dry season, the threshold for water stress was reached 17 days sooner in the 4 fires hillslopes, and also 10 days sooner on bare microsites. Periods of plant water stress were longer and bare soil patches size bigger. The increase in wildfire frequency promoted high soil organic matter contents but less available water content, stressing the importance of soil organic matter quality characterization in water-related properties.Open access funding provided by FCT|FCCN (b-on). This work was funded and performed within the scope of the CASCADE-PROJECT (Catastrophic shifts in drylands: how can we prevent ecosystem degradation? Grant agreement: 28306), funded by the European Commission (FP7-ENV.2011.2.1.4-2-Behaviour o ecosystems, thresholds and tipping points). We acknowledge financial support to CESAM by FCT/MCTES thought national funds (UIDP/50017/2020+UIDB/50017/2020+LA/P/0094/2020). We also acknowledge financial support the University of Aveiro through the assistant research contract of Oscar GonzĂĄlez-Pelayo (CDL-CTTRI-97-ARH/2018 (REF. 190-97-ARH/2018), and to the MED & CHANGE-University of Ăvora through the auxiliary research contract (Ref. UIDB/05183/2020). Thanks are also due to FCT for the research contract of SĂ©rgio Prats (CDL-CTTRI-88-ARH/2018 REF.-138-88-ARH/2018) and auxiliary research contract (CEECIND/01473/2020), and Maruxa Malvar (SFRH/BPD/97977/2013), and the IF research grant of Jacob Keizer (IF/01465/2015) funded by national funds (OE), through the Portuguese Foundation for Science and Technology (FCT/MCTES)
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