118 research outputs found
Interaction with Nearly Environment and Old Structure for a Deep Excavation. Case History in Bucharest
The paper presents the influence of a deep excavation performed in Bucharest on the adjacent ground and on some old buildings around it; the damages and effects appeared during the excavation and the remedial measures are presented in detail, too. The excavation was designed to be 16.15 meters deep, sustained by a slurry wall enclosure of 60 cm thickness and pre-stressed anchors, and steel struts. Due to an accident that occured to the trench walls, a thorough monitoring by instrumentation started. The results of this monitoring are shown
Utilizarea procesului de ierarhizare analitică în selectarea celor mai importante produse forestiere nelemnoase din judeţul Iaşi
In Romania, the non-wood forest products are mainly represented by the fauna of hunting interest, forest fruits, truffles and edible mushrooms and medicinal plants. The aim of this research was to study the most important non-wood forest products from Iaşi County. The analyze model used in similar studies done in the case of other counties across Romania was taken into account. The Analytic Hierarchy Process (AHP) was used to assess the performance of selected alternatives by means of pairwise comparisons. The analyses were carried out using the Expert Choice Desktop software package. Honey and pheasant were the most promising non-wood forest products, while the less promising was the European elderberry. According to the results of this study, we conclude that Iaşi County has a great potential for harvesting and marketing of NWFPs
Sudden drop of fractal dimension of electromagnetic emissions recorded prior to significant earthquake
The variation of fractal dimension and entropy during a damage evolution
process, especially approaching critical failure, has been recently
investigated. A sudden drop of fractal dimension has been proposed as a
quantitative indicator of damage localization or a likely precursor of an
impending catastrophic failure. In this contribution, electromagnetic emissions
recorded prior to significant earthquake are analysed to investigate whether
they also present such sudden fractal dimension and entropy drops as the main
catastrophic event is approaching. The pre-earthquake electromagnetic time
series analysis results reveal a good agreement to the theoretically expected
ones indicating that the critical fracture is approaching
Comment on opinion paper: Forest management and biodiversity : The role of protected areas is greater than the sum of its number of species
No abstract available
Hydrogen blending effect on fiscal and metrological instrumentation: A review
A green hydrogen (H2) economy requires a sustainable, efficient, safe, and widespread infrastructure for transporting and distributing H2 from production to consumption sites. Transporting a hydrogen/natural gas (H2NG) mixture, including pure H2, through the existing European natural gas (NG) infrastructure is considered a cost-effective solution, particularly in the transitional phase. Several reasons justify the H2NG blending option. The NG infrastructure can be efficiently repurposed to transport H2, by blending H2 with NG, to operate as H2 daily storage, matching production and demand and to enable large-scale seasonal H2 storage. Although many benefits exist, the potential of existing NG grids for transporting and distributing green H2 may face limitations due to technical, economic, or normative concerns. This paper focuses on the state of the art of the European NG transmission and distribution metrology normative framework and identifies the gaps to be filled in case of H2NG flowing into the existing grids. The paper was revised to provide a comprehensive analysis of the practical implications resulting from the H2NG blend option
Gas exchange at whole plant level shows that a less conservative water use is linked to a higher performance in three ecologically distinct pine species
Increasing temperatures and decreasing precipitation in large areas of the planet as a consequence of
global warming will affect plant growth and survival. However, the impact of climatic conditions will
differ across species depending on their stomatal response to increasing aridity, as this will ultimately
affect the balance between carbon assimilation and water loss. In this study, we monitored gas
exchange, growth and survival in saplings of three widely distributed European pine species (Pinus
halepensis, P. nigra and P. sylvestris) with contrasting distribution and ecological requirements in
order to ascertain the relationship between stomatal control and plant performance. The experiment
was conducted in a common garden environment resembling rainfall and temperature conditions
that two of the three species are expected to encounter in the near future. In addition, gas exchange
was monitored both at the leaf and at the whole-plant level using a transient-state closed chamber,
which allowed us to model the response of the whole plant to increased air evaporative demand
(AED). P. sylvestris was the species with lowest survival and performance. By contrast, P. halepensis
showed no mortality, much higher growth (two orders of magnitude), carbon assimilation (ca. 14
fold higher) and stomatal conductance and water transpiration (ca. 4 fold higher) than the other two
species. As a consequence, P. halepensis exhibited higher values of water-use efficiency than the rest of
the species even at the highest values of AED. Overall, the results strongly support that the weaker
stomatal control of P. halepensis, which is linked to lower stem water potential, enabled this species to
maximize carbon uptake under drought stress and ultimately outperform the more water
conservative P. nigra and P. sylvestris. These results suggest that under a hotter drought scenario
P. nigra and P. sylvestris would very likely suffer increased mortality, whereas P. halepensis could
maintain gas exchange and avoid water-induced growth limitation. This might ultimately foster an
expansion of P. halepensis to higher latitudes and elevations.This work was supported by the projects ECOLPIN
(AGL2011–24296) and Remedinal 3 (S2013/ MAE-
2719) of the Madrid Government, by a FPU fellowship
from the Spanish Ministry of Education, Culture
and Sport (FPU13/03410) to DS and by EU Marie
Curie (FP7–2013-IOF-625988) fellowship to EPSC
Concentric double hollow grid cathode discharges. Spectral investigations and phenomenological approach
A discharge plasma is created by simultaneously biasing two concentric spherical grids with
axisymmetric orifices. In this geometry, space charge structures in the form of multiple
quasi-spherical luminous plasma bodies appear simultaneously inside and around the
cathodes. The plasma formations are highly interdependent supplying each other with the
particle flow and current closure necessary for the maintenance of the discharge. To diagnose
these structures, space-resolved cold Langmuir probe measurements and optical emission
spectroscopy investigations were performed in the axial direction allowing for the mapping of
the axial profiles of plasma potential, electron temperature and density, ion density and optical
emission. The existence of an accelerating double layer in the vicinity of the holes has been
confirmed here, and in previous research (Teodorescu-Soare C T et al 2016 Phys. Scr. 91
034002; Schrittwieser R W et al 2017 Phys. Scr. 92 044001; Teodorescu-Soare C T et al 2019
Int. J. Mass Spectrom. 436 83). Besides the assessment of the relationship between discharge
conditions and plasma parameters in the novel cathode system, the importance of a multiple
concentric cathode discharge configuration is revealed for deposition applications
Pore-opening mechanism in trimeric P2X receptor channels
The opening of ion channels in response to ligand binding, voltage or membrane stretch underlies electrical and chemical signalling throughout biology. Two structural classes of pore-opening mechanisms have been established, including bending of pore-lining helices in the case of tetrameric cation channels, or tilting of such helices in mechanosensitive channels. In this paper, we explore how the structure of the pore changes during opening in P2X receptors by measuring the modification of introduced cysteine residues in transmembrane helices by thiol-reactive reagents, and by engineering metal bridges. Our results are consistent with the X-ray structure of the closed state, and demonstrate that expansion of the gate region in the external pore is accompanied by a significant narrowing of the inner pore, indicating that pore-forming helices straighten on ATP binding to open the channel. This unique pore-opening mechanism has fundamental implications for the role of subunit interfaces in the gating mechanism of P2X receptors and points to a role of the internal pore in ion permeation
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