1,372 research outputs found
Escayola reforzada por acción sinérgica entre aditivos del hormigón (fluidificantes, superfluidificantes y aireantes-plastificantes) y fibras de vidrio E
Through the analysis of the different compounds (plaster + additives + E glass fibres) we pretend to demostrate that a synergic action is present between certain concrete additives (superfluidifiers, fluidiflers, and airingplasticizers) and E glass fibre, on the basis of the flection resistance of plaster matrix based compound materials.Mediante el análisis de diferentes compuestos (escayola + aditivos + fibras de vidrio E) se pretende demostrar que existe una acción sinérgica entre ciertos aditivos del hormigón (superfluidificantes, fluidificantes y aireantes-plastificantes) y los refuerzos a base de fibras de vidrio E, sobre la resistencia a flexión de los materiales compuestos de matriz principal escayola
Stand-alone renewable energy auctions: The case of Peru
Electrification policies are crucial to improve the welfare of rural populationsworldwide. In this context, auctions for the deployment of stand-alone solar home systems (SASHS) are an appropriate alternative to facilitate access to electricity in rural areas. The aim of this paper is to analyze the design elements and functioning of the SASHS auction in Peru in order to derive lessons for the effective and efficient design of those auctions. Based on an analytical framework developed elsewhere, this article draws on official documents and data, secondary material and interviews with stakeholders. Our results show that some design elements are particularly suitable in this regard. In contrast to renewable electricity auctions in general, for which the volume auctioned is usually set as capacity (MW) or generation (MWh), the volume of SASHS auctions should be set in terms of the number of SASHS providing an electricity service.Geographical diversity,with different auctions per region, would ensure the adoption of a minimum amount of SASHS in a given geographical area. Financial solvency, but not technical reputation, should be required. Otherwise, only the incumbents would be able to participate in the auction. The choice of technology-specific, price-only, sealed-bid, single-item auctions brings benefits in terms of economies of scale, lower support or transaction costs and a greater transparency or simplicity. A correction factor on the remuneration which accounts for the quality of the service, as applied in the Peru auction, is suitable for this type of auctions. Finally, provision of technical information, which facilitates the participation in the auction, and the implementation of a non-disclosed ceiling price are deemed appropriate. In contrast, given the lowpresence of local companies in the Peruvian PV market, the adoption of local content requirements would lead to higher support costs without significantly increasing the local development potential.The authors would like to acknowledge Mr. Julio Eisman Valdés forhis guidance and support and Mr. Mats Marquardt (Factor) for editingsupport. Dr. Cabeza would like to thank the Catalan Government forthe quality accreditation given to her research group GREiA (2017 SGR1537). GREiA is certified agent TECNIO in the category of technology de-velopers from the Government of Catalonia. This work is partially sup-ported by ICREA under the ICREA Academia progra
Recommended from our members
Coenzyme Q10 deficiencies: pathways in yeast and humans.
Coenzyme Q (ubiquinone or CoQ) is an essential lipid that plays a role in mitochondrial respiratory electron transport and serves as an important antioxidant. In human and yeast cells, CoQ synthesis derives from aromatic ring precursors and the isoprene biosynthetic pathway. Saccharomyces cerevisiae coq mutants provide a powerful model for our understanding of CoQ biosynthesis. This review focusses on the biosynthesis of CoQ in yeast and the relevance of this model to CoQ biosynthesis in human cells. The COQ1-COQ11 yeast genes are required for efficient biosynthesis of yeast CoQ. Expression of human homologs of yeast COQ1-COQ10 genes restore CoQ biosynthesis in the corresponding yeast coq mutants, indicating profound functional conservation. Thus, yeast provides a simple yet effective model to investigate and define the function and possible pathology of human COQ (yeast or human gene involved in CoQ biosynthesis) gene polymorphisms and mutations. Biosynthesis of CoQ in yeast and human cells depends on high molecular mass multisubunit complexes consisting of several of the COQ gene products, as well as CoQ itself and CoQ intermediates. The CoQ synthome in yeast or Complex Q in human cells, is essential for de novo biosynthesis of CoQ. Although some human CoQ deficiencies respond to dietary supplementation with CoQ, in general the uptake and assimilation of this very hydrophobic lipid is inefficient. Simple natural products may serve as alternate ring precursors in CoQ biosynthesis in both yeast and human cells, and these compounds may act to enhance biosynthesis of CoQ or may bypass certain deficient steps in the CoQ biosynthetic pathway
Enhanced Parallel Generation of Tree Structures for the Recognition of 3D Images
Segmentations of a digital object based on a connectivity
criterion at n-xel or sub-n-xel level are useful tools in image topological
analysis and recognition. Working with cell complex analogous of digital
objects, an example of this kind of segmentation is that obtained from
the combinatorial representation so called Homological Spanning Forest
(HSF, for short) which, informally, classifies the cells of the complex as
belonging to regions containing the maximal number of cells sharing the
same homological (algebraic homology with coefficient in a field) information.
We design here a parallel method for computing a HSF (using
homology with coefficients in Z/2Z) of a 3D digital object. If this object
is included in a 3D image of m1 × m2 × m3 voxels, its theoretical time
complexity order is near O(log(m1 + m2 + m3)), under the assumption
that a processing element is available for each voxel. A prototype implementation
validating our results has been written and several synthetic,
random and medical tridimensional images have been used for testing.
The experiments allow us to assert that the number of iterations in which
the homological information is found varies only to a small extent from
the theoretical computational time.Ministerio de Economía y Competitividad MTM2016-81030-
Analysis of the Spanish Catches of White Hake (Urophycis tenuis) in NAFO Regulatory Area, 2000-2003
The Spanish fleet that operates in NAFO Regulatory Area has captured white hake in a regular way during the last
years. Before 2002, the level of catches of this species has not been very high (300 tons per year) and these catches
were part of the by-catch of the different fisheries that Spanish fleet carries out in NAFO Area (Greenland halibut,
skates, redfish). Catches have been increased substantially in the last two years, being captured in the year 2003
more than 1 800 tons.
The Spanish fishery directed to white hake began in the year 2002 and it is developed mainly in the Div. 3O among
the depths 200-500 meters. The biggest catches are carried out during the third quarter, and more than 80% of the
catches, in abundance and biomass, are mature
Description of the Spanish Pelagic Fishery of Oceanic Redfish (Sebastes mentella Travin) in the North Atlantic (2000-2004)
The period analyzed in this paper is 2000-2004. Data from the Spanish commercial fishery (hauls, positions, CPUE
and length distributions) were recorded on board by scientific observers of the national sampling network. The effort
data come from the Fisheries National Administration (SGPM).
The Spanish pelagic redfish fishery in ICES areas XII and XIV and in the NAFO Div. 1F and 2J showed a
significant seasonal pattern in terms of its geographical and depth distribution. The fishing season occurs mainly
during the 2nd and 3rd quarter of every year.
In the second quarter the fleet works in area XIV, between the Greenland and Iceland EEZs, in depths deeper than
500 m capturing fish of great size. Proportion of females in the catches is greater than the males. The catches length
distributions present two modes that move along the time.
In third quarter the fleet moves toward the south west to ICES Division XII and NAFO Div. 1F and 2J and depth of
hauls is less than 500 m. The length distributions of the catches are smaller than those of the second quarter and
show only one mode rather stable in time. Proportion of the males in the catches is bigger than the females. The
yields in these Divisions are smaller than in Division XIV.
The fishery in NAFO area 1F and 2J is quite similar to that one carry out in ICES Division XII, particularly in the
characteristics of the hauls (depth, season) and in the catches (distributions of sizes, sex ratio, etc)
Harmonically Trapped Quantum Gases
We solve the problem of a Bose or Fermi gas in -dimensions trapped by mutually perpendicular harmonic oscillator potentials. From the
grand potential we derive their thermodynamic functions (internal energy,
specific heat, etc.) as well as a generalized density of states. The Bose gas
exhibits Bose-Einstein condensation at a nonzero critical temperature
if and only if , and a jump in the specific heat at if and
only if . Specific heats for both gas types precisely coincide as
functions of temperature when . The trapped system behaves like an
ideal free quantum gas in dimensions. For we recover
all known thermodynamic properties of ideal quantum gases in dimensions,
while in 3D for 1, 2 and 3 one simulates behavior reminiscent of
quantum {\it wells, wires}and{\it dots}, respectively.Comment: 14 pages including 3 figures and 3 table
Evidence for early Pliocene and late Miocene transgressions in southern Patagonia (Argentina): 87Sr/86Sr ages of the pectinid “Chlamys” actinodes (Sowerby)
AbstractNumerical ages based on 87Sr/86Sr dating of calcitic shells belonging to the pectinid “Chlamys” actinodes (Sowerby) document the only late Miocene (Tortonian) sea flooding event in the Austral Basin at Cabo Buentiempo (8.95 ± 0.82 Ma, 2 s.e.), and provide evidence of the first documented early Pliocene (Zanclean) transgression in Argentina recorded at Cañadón Darwin (5.15 ± 0.18 Ma, 2 s.e., Austral Basin) and at Terraces of Cerro Laciar (5.10 ± 0.21 Ma, 2 s.e.), southern San Jorge Basin). The sedimentary rocks deposited during the Tortonian are correlated with the youngest beds deposited by the “Entrerriense Sea” that covered northern Patagonia. The Zanclean marine episode is correlated with the long-term cycle represented in the Southern Hemisphere by the flooding events recorded in Cockburn and James Ross Islands (Antarctica) and in North-Central Chile
- …