243 research outputs found
Aerobic biodegradation of a mixture of monosubstituted phenols in a sequencing batch reactor
A sequencing batch reactor (SBR) was inoculated with p-nitrophenol-degrading activated sludge to biodegrade a mixture of monosubstituted phenols: p-nitrophenol (PNP), PNP and o-cresol; and PNP, o-cresol and o-chlorophenol. Settling times were progressively decreased to promote biomass granulation. PNP was completely biodegraded. The PNP and o-cresol mixture was also biodegraded although some transitory accumulation of intermediates occurred (mainly hydroquinone and catechol). o-Chlorophenol was not biodegraded and resulted in inhibition of o-cresol and PNP biodegradation and complete failure of the SBR within a few days. The biomass had very good settling properties when a settling time of 1 min was applied: sludge volume index (SVI₅) below 50 mL g⁻¹, SVI₅/SVI₃₀ ratio of 1 and average particle size of 200 μm
Inhibition of the anammox activity by aromatic compounds
The short-term effect of several aromatic compounds (o-cresol, p-nitrophenol, o-chlorophenol and quinoline) was evaluated over granular anammox sludge cultivated over 2 years in a Sequencing Batch Reactor (SBR). The anammox granular sludge had an average size of 1.0 ± 0.2 mmand was enriched in Brocadia sp. Specific Anammox Activity (SAA) batch tests with this granular biomass were carried out in the presence of o-cresol, p-nitrophenol, o-chlorophenol, quinoline and their mixtures. The anammox biomass was never exposed to the tested aromatic compounds, prior to the SAA tests. The concentration and the mixture of aromatic compounds had a strong effect over the loss of the anammox activity. The higher the concentrations of the aromatic compounds, the higher the reduction of the SAA. Quinoline and p-nitrophenol have a lower negative effect compared to o-cresol and o- chlorophenol. The Luong inhibition model seems to adjust better the inhibition of anammox biomass by the tested aromatic compounds. Depending on the aromatic compound, toxic or inhibitory effect was measured. o-Cresol and o-chlorophenol caused a toxic effect whereas p-nitrophenol and quinoline produced an inhibitory effect. In general, synergistic effects were observed when mixtures of aromatic compounds were studied
A New Approach To Expandable Structures: Crossed Expandable Frames (X-Frames)
The use of expandable structures in the field of building began in the 1960s, based on the pioneering work of Emilio Pérez Piñero. They underwent significant developments at the end of the 20th century, with typologies based on scissors or bundle modules. Until now, this typology has not been further enhanced, despite some very interesting contributions.
These studies are usually based on straight bar expandable structures, although there are some interesting proposals based on the deployability of parallel arc systems, even in real buildings. However, other possible types of expandable structures have not been explored to date.
In this paper, a new system for expandable structures is proposed, which opens new and interesting design possibilities based on the same folding principle. The system consists of deploying elements such as arches or frames with multiple intersections. Solutions for cylindrical vaults with horizontal axis joints and more complex geometries such as conoids are proposed, as well as domes with vertical and horizontal axis joints. Finally, other structures with special kinematic compatibility difficulties, such as concentric domes or toroids, are also studied.MINECO; BIA2016-79459-
Highly-sensitive anisotropic porous silicon based optical sensors
The modeling, fabrication and characterization of PSi fabricated from both (110) and (100) surface oriented silicon for optical sensing is thoroughly reported. First, based on the generalized Bruggeman method, the birefringence and sensitivity of the fabricated membranes were calculated as a function of the fabrication parameters such as porosity and pore sizes; and external effects, such as the pores surface oxidation. Thereafter we report on the fabrication of PSi membranes from (110) and (100) surface oriented silicon with pore sizes in the range of 50-80 nm, and the characterization of their birefringence using a polarimetric setup. Their sensitivities were determined by filling the pores with several liquids having different refractive index. As a result, sensitivities as high as 1407 nm/RIU were obtained for the (110) samples at a 1500 nm wavelength and 382 nm/RIU for the (100) samples at the same wavelength
Handling missing values in trait data
Aim: Trait data are widely used in ecological and evolutionary phylogenetic comparative studies, but often values are not available for all species of interest. Traditionally, researchers have excluded species without data from analyses, but estimation of missing values using imputation has been proposed as a better approach. However, imputation methods have largely been designed for randomly missing data, whereas trait data are often not missing at random (e.g., more data for bigger species). Here, we evaluate the performance of approaches for handling missing values when considering biased datasets. Location: Any. Time period: Any. Major taxa studied: Any. Methods: We simulated continuous traits and separate response variables to test the performance of nine imputation methods and complete-case analysis (excluding missing values from the dataset) under biased missing data scenarios. We characterized performance by estimating the error in imputed trait values (deviation from the true value) and inferred trait–response relationships (deviation from the true relationship between a trait and response). Results: Generally, Rphylopars imputation produced the most accurate estimate of missing values and best preserved the response–trait slope. However, estimates of missing data were still inaccurate, even with only 5% of values missing. Under severe biases, errors were high with every approach. Imputation was not always the best option, with complete-case analysis frequently outperforming Mice imputation and, to a lesser degree, BHPMF imputation. Mice, a popular approach, performed poorly when the response variable was excluded from the imputation model. Main conclusions: Imputation can handle missing data effectively in some conditions but is not always the best solution. None of the methods we tested could deal effectively with severe biases, which can be common in trait datasets. We recommend rigorous data checking for biases before and after imputation and propose variables that can assist researchers working with incomplete datasets to detect data biases and minimize errors.Fil: Johnson, Thomas F.. University of Reading; Reino UnidoFil: Isaac, Nick J. B.. Centre For Ecology And Hydrology; Reino UnidoFil: Paviolo, Agustin Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina. Centro de Investigaciones del Bosque Atlántico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: González Suárez, Manuela. University of Reading; Reino Unid
Temperature Sensor Based on Colloidal Quantum Dots PMMA Nanocomposite Waveguides
In this paper, integrated temperature sensors based on active nanocomposite planar waveguides are presented. The nanocomposites consist of cadmium selenide (CdSe) and cadmium telluride (CdTe) quantum dots (QDs) embedded in a polymethylmethacrylate (PMMA) matrix. When the samples are heated in a temperature range from 25 to 50 , the waveguided photoluminescence of QDs suffers from a strong intensity decrease, which is approximately quadratic dependent on temperature. Moreover, the wavelength peak of the waveguided emission spectrum of CdTe-PMMA shows a blue shift of 0.25 , whereas it remains constant in the case of CdSe-PMMA. A temperature resolution of 0.1 is obtained. QD waveguides have great potential for the development of photonic sensors because of their integration, multiplexing, and roll-to-roll fabrication capabilities.Manuscript received February 21, 2012; revised May 8, 2012; accepted July 18, 2012. Date of publication July 24, 2012; date of current version August 9, 2012. This work was supported in part by the Spanish MICINN and Generalitat Valenciana under Grant TEC-2011-06756-C03-03 and Grant PROMETEO/2009/074, the Plan Nacional I + D under Project TEC2011-29120-C05-01 and Project TEC2011-29120-C05-05, and the Infraestructura FEDER UPVOV08-3E-008. The associate editor coordinating the review of this paper and approving it for publication was Prof. E. H. Yang.Bueno Martínez, A.; Suárez Álvarez, I.; Abargues, R.; Sales Maicas, S.; J. MARTÍNEZ-PASTOR (2012). Temperature Sensor Based on Colloidal Quantum Dots PMMA Nanocomposite Waveguides. IEEE Sensors Journal. 12(10):3069-3074. https://doi.org/10.1109/JSEN.2012.2210037S30693074121
Single Step Deposition of an Interacting Layer of Perovskite Matrix with Embedded Quantum Dots
Hybrid lead halide perovskite (PS) derivatives have emerged as very promising materials for the development of optoelectronic devices in the last few years. At the same time, inorganic nanocrystals with quantum confinement (QDs) possess unique properties that make them suitable materials for the development of photovoltaics, imaging and lighting applications, among others. In this work, we report on a new methodology for the deposition of high quality, large grain size and pinhole free PS films (CH3NH3PbI3) with embedded PbS and PbS/CdS core/shell Quantum Dots (QDs). The strong interaction between both semiconductors is revealed by the formation of an exciplex state, which is monitored by photoluminescence and electroluminescence experiments. The radiative exciplex relaxation is centered in the near infrared region (NIR), ≈1200 nm, which corresponds to lower energies than the corresponding band gap of both perovskite (PS) and QDs. Our approach allows the fabrication of multi-wavelength light emitting diodes (LEDs) based on a PS matrix with embedded QDs, which show considerably low turn-on potentials. The presence of the exciplex state of PS and QDs opens up a broad range of possibilities with important implications in both LEDs and solar cells.Generalitat Valenciana
PROMETEOII/2014/020
PROMETEOII/2014/059
ISIC/2012/008
Spanish MINECO (Ministry of Economy and Competitiveness)
MAT2013-47192-C3-1-R
MAT2015-70611-ERC
TEC2014-53727-C2-1-R
Spanish MINEC
A New Type of Reciprocal Structures: Deployable Yurts for Emergency Situations
[Abstract] Deployable structures are a good solution for emergency buildings due to their lightweight and compact characteristics that allow them to be transported to wherever they are needed, especially in emergency situations. Generally, folding structures have been designed with modules comprised of straight bars, forming a scissor joint. They are efficient systems, although they have the disadvantage of being excessively deformable, requiring the use of large and consequently heavier sections.
Recently, interesting proposals have been made based on deployable systems with parallel arches and also with arches or frames with multiple intersections. Dome solutions have been proposed with vertical and horizontal axis joints with reciprocal support in the linkages that increase their efficiency.
In this document, a new system is proposed for deployable structures based on a similar system of multiple intersections, but composed of straight bars. This allows them to be applied to a traditional and highly effective design, the yurt. The deployable yurts developed have multiple applications for common types of structures used in emergency situations.This study is part of the research project "Deployable and modular constructions for situations of humanitarian catastrophe", funded by the Ministry of Economy and Competitiveness of the Kingdom of Spain with reference BIA2016-79459-R
A new reciprocal linkage for expandable emergency structures
Expandable structures have certain qualities in terms of lightness and transportability which make them very useful as emergency buildings, a research line that is being developed by the authors. However, these structures have some disadvantages due to their reduced rigidity and great deformability, issues that could limit their use. This paper analyzes a reciprocal linkage that considerably improves one of the main problems of expandable structures, which is their lack of rigidity. The extremely strict geometrical conditions for this proposed linkage and the mechanical behaviour are examined. Two series of tests were carried out, with specimens formed by four bars supported reciprocally around the proposed linkage. In the first case, the bars had their ends simply resting on the base and in the second one displacement was restricted at their ends. Theoretical analysis and the experimental tests results are also included. The tests make it possible to define the failure patterns of the different elements of the linkages, bars or bolts. The theoretical models and the experimental results show that the proposed reciprocal linkages are highly effective. Tests of plane scissor meshes were also carried out using reciprocal linkages, showing a very significant reduction in their displacements.MINECO: BIA2016-79459-
Deployable Cylindrical Vaults With Reciprocal Linkages for Emergency Buildings
Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract]
Deployable bar structures are especially useful for emergency buildings. These structures require simplicity and ease of assembly and their performance can be improve by using reciprocal linkage at their bars ends. This reciprocal configuration determines singular constructive conditions that allow all types of cylindrical vaults. This article develops this new system, from a previously theoretical analysis to a test campaign that allows verifying the validity of the proposal. Comparing these results with those resulting from construction systems with straight scissor-like elements or imposed curvature, shows the adequacy of this new proposal, verifying the advantages of the reciprocal joints in cylindrical vaults configurations.This study is part of the research project “Deployable and modular constructions for situations of humanitarian catastrophe”, funded by the Ministry of Economy and Competitiveness of the Kingdom of Spain with reference BIA2016-79459-R. Funding for open access charge: Universidade da Coruña/CISU
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