967 resultados para PCM wall
Resumo:
The impact of disruptions in JET became even more important with the replacement of the previous Carbon Fiber Composite (CFC) wall with a more fragile full metal ITER-like wall (ILW). The development of robust disruption mitigation systems is crucial for JET (and also for ITER). Moreover, a reliable real-time (RT) disruption predictor is a pre-requisite to any mitigation method. The Advance Predictor Of DISruptions (APODIS) has been installed in the JET Real-Time Data Network (RTDN) for the RT recognition of disruptions. The predictor operates with the new ILW but it has been trained only with discharges belonging to campaigns with the CFC wall. 7 realtime signals are used to characterize the plasma status (disruptive or non-disruptive) at regular intervals of 1 ms. After the first 3 JET ILW campaigns (991 discharges), the success rate of the predictor is 98.36% (alarms are triggered in average 426 ms before the disruptions). The false alarm and missed alarm rates are 0.92% and 1.64%.
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This paper explains a procedure for the choice of ballast modules used for the design of direct continuous foundation in karst terrain. The presence of dangerous cavities is introduced in this procedure thereby evaluating risk failure. It also provides pertinent guidelines to direct the geotechnical survey of the terrain.
Resumo:
This paper explains a procedure for the choice of ballast modules used for the design of direct continuous foundation in karst terrain. The presence of dangerous cavities is introduced in this procedure thereby evaluating risk failure. It also provides pertinent guidelines to direct the geotechnical survey of the terrain.
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Growth and biomechanics of etiolated hypocotyls from Arabidopsis thaliana lines overexpressing xyloglucan endotransglucosylase/hydrolase AtXTH18, AtXTH19, AtXTH20, and PttXET16-34 were studied. Overexpression of AtXTH18, AtXTH19, and AtXTH20 stimulated growth of hypocotyls, while PttXET16-34 overexpression did not show this effect. In vitro extension of frozen/thawed hypocotyls measured by a constant-load extensiometer started from a high-amplitude initial deformation followed by a slow time-dependent creep. Creep of growing XTH-overexpressing (OE) hypocotyls was more linear in time compared with the wild type at pH 5.0, reflecting their higher potential for long-term extension. XTH-OE plants deposited 65?84% more cell wall material per hypocotyl cross-sectional area than wild-type plants. As a result, their wall stress under each external load was lower than in the wild-type. Growing XTH-OE hypocotyls had higher values of initial deformation·stress?1 compared with the wild type. Plotting creep rates for each line under different loads against the respective wall stress values gave straight lines. Their slopes and intercepts with the abscissa correspond to ? (in vitro cell wall extensibility) and y (in vitro cell wall yield threshold) values characterizing cell wall material properties. The wall material in XTH-OE lines was more pliant than in the wild type due to lower y values. In contrast, the acid-induced wall extension in vitro resulted from increasing ? values. Thus, three factors contributed to the XTH-OE-stimulated growth in Arabidopsis hypocotyls: their more linear creep, higher values of initial deformation·stress?1, and lower y values.
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It is known that a green wall brings some advantages to a building. It constitutes a barrier against solar radiation, thus decreasing and delaying the incoming heat flux. The aim of this study is to quantify such advantages through analytical comparison between two facades, a vegetal facade and a conventional facade. Both were highly insulated (U-value = 0.3 W/m2K) and installed facing south on the same building in the central territory of Spain. In order to compare their thermal trend, a series of sensors were used to register superficial and indoor air temperature. The work was carried out between 17th August 2012 and 1st October 2012, with a temperature range of 12°C-36°C and a maximum horizontal radiation of 1020 W/m2. Results show that the indoor temperature of the green wall module was lower than the other. Besides, comparing superficial outdoor and indoor temperatures of the two walls to outdoor air temperatures, it was noticed that, due to the shading plants, the green wall superficial temperature was 5 °C lower on the facade, while the bare wall temperature was 15 °C higher. The living wall module temperature was 1.6 °C lower than the outdoor, while the values of the conventional one were similar to the outdoor air temperature.
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Sugarcane leaf shows the classical arrangement of cells which defines a C4 species. Vascular bundles consist of xylem, phloem and fibres, surrounded by an outer layer of sclereids and an inner ring of stone cells associated with the phloem. Some sclereids located below and above the vascular bundles act as docking cells and connect the vascular bundle to the internal surfaces of upper and lower layers of the epidermis. A compact mass of sclereids occupies the total internal volume of the leaf edge. Neither docking cells nor the internal mass of sclereids in the edge were markedly coloured by acriflavin or phloroglucinol, indicating the absence of lignin in their cell walls. However, such staining indicated that fibres of the vascular bundle and the external layer of sclereids were strongly lignified. Incubation of leaf discs with an elicitor produced by the pathogen Sporisorium scitamineum increased the thickness of the lignified cell walls of sclereids as well as the mid and small xylem vessels, as a possible mechanical defense response to the potential entry of the pathogen.
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The plant cuticle has traditionally been conceived as an independent hydrophobic layer that covers the external epidermal cell wall. Due to its complexity, the existing relationship between cuticle chemical composition and ultra-structure remains unclear to date. This study aimed to examine the link between chemical composition and structure of isolated, adaxial leaf cuticles of Eucalyptus camaldulensis and E. globulus by the gradual extraction and identification of lipid constituents (cutin and soluble lipids), coupled to spectroscopic and microscopic analyses. The soluble compounds and cutin monomers identified could not be assigned to a concrete internal cuticle ultra-structure. After cutin depolymerization, a cellulose network resembling the cell wall was observed, with different structural patterns in the regions ascribed to the cuticle proper and cuticular layer, respectively. Our results suggest that the current cuticle model should be revised, stressing the presence and major role of cell wall polysaccharides. It is concluded that the cuticle may be interpreted as a modified cell wall region which contains additional lipids. The major heterogeneity of the plant cuticle makes it difficult to establish a direct link between cuticle chemistry and structure with the existing methodologies.
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An approximate procedure for studying harmonic soil-structure interaction problems is presented. The presence of Rayleigh waves is considered and the resulting governing equations of the dynamic soil-structure system are solved in the time domain. With this method the transient and steady states of a vibratory motion and also the nonlinear behaviour of the soil can be studied. As an example, the dynamic earth pressure against a rigid retaining wall is investigated. The loads are assumed to be harmonic Rayleigh waves with both static and dynamic surface surcharges. The dependence of the results on the excitation frequency is shown.
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The design of containment walls suffering seismic loads traditionally has been realized with methods based on pseudoanalitic procedures such as Mononobe- Okabe's method, which it has led in certain occasions to insecure designs, that they have produced the ruin of many containment walls suffering the action of an earthquake. A method is proposed in this papers for the design of containment walls in different soils, suffering to the action of an earthquake, based on the Performance-Based Seismic Design.
Resumo:
The design of containment walls suffering seismic loads traditionally has been realized with methods based on pseudoanalitic procedures such as Mononobe-Okabe's method, which it has led in certain occasions to insecure designs, that they have produced the ruin of many containment walls suffering the action of an earthquake. The recommendations gathered in Mononobe-Okabe's theory have been included in numerous Codes of Seismic Design. It is clear that a revision of these recommendations must be done. At present there is taking place an important review of the design methods of anti-seismic structures such as containment walls placed in an area of numerous earthquakes, by means of the introduction at the beginning of the decade of 1990 the Displacement Response Spectrum (DRS) and the Capacity Demand Diagram (CDD) that suppose an important change in the way of presenting the Elastic Response Spectrum (ERS). On the other hand in case of action of an earthquake, the dynamic characteristics of a soil have been referred traditionally to the speed of the shear waves that can be generated in a site, together with the characteristics of plasticity and damping of the soil. The Principle of the energy conservation explains why a shear upward propagating seismic wave can be amplified when travelling from a medium with high shear wave velocity (rock) to other medium with lower velocity (soil deposit), as it happened in the earthquake of Mexico of 1985. This amplification is a function of the speed gradient or of the contrast of impedances in the border of both types of mediums. A method is proposed in this paper for the design of containment walls in different soils, suffering to the action of an earthquake, based on the Performance-Based Seismic Design.
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This paper presents an extensive and useful comparison of existing formulas to estimate wave forces on crown walls. The paper also provides valuable insights into crown wall behaviour, suggesting the use of formulas for prior sizing and recommending, in any case, tests on a physical model in order to confirm the final design. The authors helpfully advise to use more than one method to obtain results closer to reality, always taking into account the test conditions under which each formula was developed
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La edificación es un sector de enorme influencia en la evolución del consumo de energía y las emisiones de CO2. Teniendo en cuenta que en estos momentos hay 3,5 millones de viviendas vacías y que los próximos años no va a haber un aumento en la demanda de vivienda nueva, la rehabilitación sostenible del parque residencial existente es una tarea prioritaria y sobre la que hay que prestar especial interés. Dado que aún queda mucho donde actuar, es necesario hacer una reflexión sobre cómo se está rehabilitando para poder mejorar en el futuro. Por ello, el objetivo del presente trabajo es analizar algunas estrategias adoptadas hasta ahora en el parque inmobiliario y su aplicación en un caso de estudio, mediante la mejora de la fachada de un edificio de viviendas situado en Madrid.
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Plant resistance to pathogens relies on a complex network of constitutive and inducible defensive barriers. The plant cell wall is one of the barriers that pathogens need to overcome to successfully colonize plant tissues. The traditional view of the plant cell wall as a passive barrier has evolved to a concept that considers the wall as a dynamic structure that regulates both constitutive and inducible defense mechanisms, and as a source of signaling molecules that trigger immune responses. The secondary cell walls of plants also represent a carbon-neutral feedstock (lignocellulosic biomass) for the production of biofuels and biomaterials. Therefore, engineering plants with improved secondary cell wall characteristics is an interesting strategy to ease the processing of lignocellulosic biomass in the biorefinery. However, modification of the integrity of the cell wall by impairment of proteins required for its biosynthesis or remodeling may impact the plants resistance to pathogens. This review summarizes our understanding of the role of the plant cell wall in pathogen resistance with a focus on the contribution of lignin to this biological process.
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En la coleorriza en semillas de Brachypodium son abundantes los mananos y estos van desapareciendo conforme progresa la germinación (entre 12-27 h), al mismo tiempo se observa un pico de actividad endo-beta-mananasa. Se ha establecido que de los 6 miembros de la familia MAN en B. distachyon 3 se expresan en el embrión en germinación y BdMAN3 también es abundante en la aleurona.
Resumo:
The cell wall is a dynamic structure that regulates both constitutive and inducible plant defence responses. Different molecules o DAMPs (damage-associated molecular patterns) can be released from plant cell walls upon pathogen infection or wounding and can trigger immune responses. To further characterize the function of cell wall on the regulation of these immune responses, we have performed a biased resistance screening of putative/well-characterized primary/secondary Arabidopsis thaliana cell wall mutants (cwm). In this screening we have identified more than 20 cwm mutants with altered susceptibility/resistance to at least one of the following pathogens: the necrotrophic fungi Plectosphaerella cucumerina, the vascular bacterium Ralstonia solanacearum, the biotrophic oomycete Hyaloperonospora arabidopsidis and the powdery mildew fungus Erisyphe cruciferarum. We found that cell wall extracts from some of these cwm plants contain novel DAMPs that activate immune responses and conferred enhanced resistance to particular pathogens when they were applied to wild-type plants. Using glycomic profiling we have performed an initial characterization of the active carbohydrate structures present in these cwm wall fractions, and we have determined the signalling pathways regulated by thesse fractions. . The data generated with this collection of wall mutants support the existence of specific correlations between cell wall structure/composition, resistance to particular type of pathogens and plant fitness. Remarkably, we have identified specific cwm mutations that uncoupled resistance to pathogens from plant trade-offs, further indicating the plasticity of wall structures in the regulation of plant immune responses.