40 resultados para BACKING STORAGE
em Universidad Politécnica de Madrid
Resumo:
Geological storage of CO2 is nowadays internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize its effects on the global climatology. One of the main options is to store the CO2 in deep saline aquifers at more than 800 m depth, because it achieves its supercritical state. Among the most important aspects concerning the performance assessment of a deep CO2 geological repository is the evaluation of the CO2 leakage rate from the chosen storage geological formation. Therefore, it is absolutely necessary to increase the knowledge on the interaction among CO2, storage and sealing formations, as well as on the flow paths for CO2 and the physico-mechanical resistance of the sealing formation. Furthermore, the quantification of the CO2 leakage rate is essential to evaluate its effects on the environment. One way to achieve this objective is to study of CO2 leakage on natural analogue systems, because they can provide useful information about the natural performance of the CO2, which can be applied to an artificial CO2 geological storage. This work is focused on the retention capacity of the cap-rock by measuring the diffuse soil CO2 flux in a site selected based on: i) the presence of a natural and deep CO2 accumulation; ii) its structural geological characteristics; and iii) the nature of the cap-rocks. This site is located in the so-called Mazarrón-Gañuelas Tertiary Basin, in the Guadalentin Valley, province of Murcia (Spain) Therefore the main objective of this investigation has been to detect the possible leakages of CO2 from a deep saline aquifer to the surface in order to understand the capability of this area as a natural analogue for Carbon Capture and Sequestration (CCS). The results obtained allow to conclude that the geological sealing formation of the basin seems to be appropriate to avoid CO2 leakages from the storage formation.
Resumo:
La pérdida de tensión por relajación en las armaduras activas afecta de forma importante a las estructuras de hormigón pretensado. Por ello se realizan ensayos de relajación de los alambres y cordones de pretensado tras su fabricación. Después, el material es enrollado y almacenado durante periodos que en ocasiones pueden superar el año de duración. Generalmente se desprecia la influencia que estas operaciones posteriores a la fabricación pueden tener sobre el material. Sin embargo, diversos fabricantes y suministradores han constatado experimentalmente que, en ocasiones, el material almacenado durante un periodo prolongado presenta pérdidas de relajación mayores que inmediatamente tras su fabricación. En este trabajo se realizan ensayos de laboratorio para comprobar la influencia que el radio de enrollamiento y el periodo de almacenamiento tienen sobre las pérdidas de relajación. También se propone un modelo analítico que permite predecir de manera razonablemente aproximada el valor del ensayo de relajación sobre un alambre sometido a un enrollamiento prolongado. Este modelo explica la evolución del perfil de tensiones durante el proceso de enrollamiento-almacenamiento-desenrollamiento, así como la influencia de las tensiones residuales
Resumo:
Arquitectura de almacenamiento para imágenes JPEG2000 basado en la fragmentación del fichero para poder almacenar los datos en diferentes discos para optimizar el almacenamiento en función de la calidad de los datos y posibilitar el aumento de transferencia.
Resumo:
With the rising prices of the retail electricity and the decreasing cost of the PV technology, grid parity with commercial electricity will soon become a reality in Europe. This fact, together with less attractive PV feed-in-tariffs in the near future and incentives to promote self-consumption suggest, that new operation modes for the PV Distributed Generation should be explored; differently from the traditional approach which is only based on maximizing the exported electricity to the grid. The smart metering is experiencing a growth in Europe and the United States but the possibilities of its use are still uncertain, in our system we propose their use to manage the storage and to allow the user to know their electrical power and energy balances. The ADSM has many benefits studied previously but also it has important challenges, in this paper we can observe and ADSM implementation example where we propose a solution to these challenges. In this paper we study the effects of the Active Demand-Side Management (ADSM) and storage systems in the amount of consumed local electrical energy. It has been developed on a prototype of a self-sufficient solar house called “MagicBox” equipped with grid connection, PV generation, lead–acid batteries, controllable appliances and smart metering. We carried out simulations for long-time experiments (yearly studies) and real measures for short and mid-time experiments (daily and weekly studies). Results show the relationship between the electricity flows and the storage capacity, which is not linear and becomes an important design criterion.
Resumo:
A total of 72 eggs from a group of 100 white laying hens housed in standard cages were analyzed. Thirty-six eggs were retired when the hens had 44 week of age and the other 36 eggs were retired eight weeks afterwards. Each group of 36 eggs was radomly divided in three groups of 12 eggs. First group was analyzed at once (storage system C); second one was kept during one week in the refrigerator (5ºC) (storage system R), and third group were kept also one week but on ambient temperature (25ºC) (storage system ET). The hen age, egg weight and storage system had not significant (P>0.05) effect on shell thickness. The specific gravity (SG) has a positive relation with shell quality. The egg class and storage system significantly (P<0,05) affected to SG, while no influence of bird age on this variable was observed. The yolk color increased with hen age but storage system had not effect on this variable. The increase of the hen age and the R and AT storage systems significantly (P<0.05) reduced albumen height (H) and the interaction hen age x storage system was significant (P<0.025) for this variable. The reduction of the H due to R and ET storage systems was higher in the eggs from hens with 52 weeks of age than in those from hens with 44 weeks of age. The Haugh units (HU) was significantly (P<0.05) affected by hen age, egg class and storage system. The hen age increase reduced HU and the R and ET eggs had lower HU than C eggs. It is concluded that the bird age and storage system with high temperatures reduced the egg quality.
Resumo:
A total of 108 eggs from a group of 100 brown laying hens housed in standard cages were analyzed. Thirty-six eggs were retired when the hens had 30 week of age, other 36 eggs were retired when the hens had 35 week of age and the remaining 36 eggs were retired five weeks afterwards. Each group of 36 eggs was radomly divided in three groups of 12 eggs. First group was analyzed at once, second group one was kept during one week in the refrigerator (5°C) and third group was kept also one week but on ambient temperature (25°C). Shell color, shell thickness, specific gravity, albumen height and Haugh units wre obtained. The bird age had significant effect on shell color and shell thickness, but the storage system had not influence on such variables. The hen age had not effect on specific gravity, but the storage system affected to this variable. Hen age and storage system had significant influence (P<0.05) on albumen height and Haugh units, and the interaction age × storage system was significant for these variables. The specific gravity had positive relations with shell thickness, yolk color, albumen height and Haugh units. It is concluded that bird age and storage system under high temperatures reduced the egg quality.
Resumo:
Massive integration of renewable energy sources in electrical power systems of remote islands is a subject of current interest. The increasing cost of fossil fuels, transport costs to isolated sites and environmental concerns constitute a serious drawback to the use of conventional fossil fuel plants. In a weak electrical grid, as it is typical on an island, if a large amount of conventional generation is substituted by renewable energy sources, power system safety and stability can be compromised, in the case of large grid disturbances. In this work, a model for transient stability analysis of an isolated electrical grid exclusively fed from a combination of renewable energy sources has been studied. This new generation model will be installed in El Hierro Island, in Spain. Additionally, an operation strategy to coordinate the generation units (wind, hydro) is also established. Attention is given to the assessment of inertial energy and reactive current to guarantee power system stability against large disturbances. The effectiveness of the proposed strategy is shown by means of simulation results.
Resumo:
Prestressed structures are susceptible to relaxation losses which are of significant importance in structural design. After being manufactured, prestressing wires are coiled to make their storage and transportation easier. The possible deleterious effects of this operation on the stress relaxation behavior of prestressing steel wires are usually neglected, though it has been noticed by manufacturers and contractors that when relaxation tests are carried out after a long-time storage, on occasions relaxation losses are higher than those measured a short time after manufacturing. The influence of coiling on the relaxation losses is checked by means of experimental work and confirmed with a simple analytical model. The results show that some factors like initial residual stresses, excessively long-time storage or storage at high temperatures,can trigger or accentuate this damage. However, it is also shown that if the requirements of standards are fulfilled (minimum coiling diameters) these effects can be neglected.
Resumo:
La pérdida de tensión por relajación en las armaduras activas afecta de forma importante a las estructuras de hormigón pretensado. Por ello se realizan ensayos de relajación de los alambres y cordones de pretensado tras su fabricación. Después, el material es enrollado y almacenado durante periodos que en ocasiones pueden superar el año de duración. Generalmente se desprecia la influencia que estas operaciones posteriores a la fabricación pueden tener sobre el material. Sin embargo, diversos fabricantes y suministradores han constatado experimentalmente que, en ocasiones, el material almacenado durante un periodo prolongado presenta pérdidas de relajación mayores que inmediatamente tras su fabricación. En este trabajo se realizan ensayos de laboratorio para comprobar la influencia que el radio de enrollamiento y el periodo de almacenamiento tienen sobre las pérdidas de relajación. También se propone un modelo analítico que permite predecir de manera razonablemente aproximada el valor del ensayo de relajación sobre un alambre sometido a un enrollamiento prolongado. Este modelo explica la evolución del perfil de tensiones durante el proceso de enrollamiento- almacenamiento-desenrollamiento, así como la influencia de las tensiones residuales.Stress relaxation losses on active reinforcement have significant impact on prestressed concrete structures. This is why relaxation tests are carried out on prestressing steel wires and strands after being manufactured. Then, these materials are coiled and stored for a long-term period, sometimes in excess of one year. The influence of these operations, carried out after manufacturing, is usually neglected. Nevertheless, some manufacturers and contractors have noticed that, sometimes, when relaxation tests are carried out after a long-term storage, the relaxation losses found are higher than those measured immediately after manufacturing. In this work, lab tests are performed to check the influence of the coiling radius and the period of storage on the relaxation test. In addition to this, an analytical model is presented to predict the results of a relaxation
Resumo:
Samples of "Golden" and "Granny Smith" apples and "Conference" and "Doyenne of Cornice" pears have been tested. A great effect of storage conditions has been detected for pear but not for apple varieties. Both apple cultivars show to be equally resistant to quasi-static and to dinamic loading while pear varieties show great differences. All these effects can be quantified in order to describe mathematically species and varieties behavior.
Resumo:
Diseases that affect garlic during storage can lead to severe economic losses for farmers worldwide. One causal agent of clove rot is Fusarium proliferatum. Here, the progress of clove rot caused by F. proliferatum and its dependence on different storage conditions and cultivar type were studied. The effect of temperature on mycelial growth, conidial viability, and fungal survival during garlic commercial storage was documented. Samples of 50 bulbs from a randomized field trial with three different clonal generations for purple garlic (F3, F4 and F5) and the F4 clonal generation for white garlic were labeled and stored for two months (short-term storage). In addition, another sample of the F5 clonal generation of purple garlic was stored for 6 months after harvest (long-term storage). The presence of the pathogen and the percentage of symptomatic cloves were evaluated. A notable difference in the rot severity index (RSI) of different garlic varieties was observed. In all studied cases, clove rot increased with storage time at 20 ◦ C, and the white garlic variety had a higher index of rot severity after two months of storage. Additionally, there were clear differences between the growth rates of F. proliferatum isolates. Studies conducted on the temperature responses of the pathogen propagules showed that expo- sure for at least 20 min at 50 ◦ C was highly effective in significantly reducing the viability of fungal conidia. Pathogenicity studies showed that the fungus is pathogenic in all commercial varieties. However, there were significant differences in varietal susceptibility between Chinese and white garlic type cultivars (81.84 ± 16.44% and 87.5 ± 23.19% symptomatic cloves, respectively) and purple cultivars (49.06 ± 13.42% symptomatic cloves)
Resumo:
CO2 Emission from two old mine drillings (Mt. Amiata, Central Italy) as a possible example of storage and leakage of deep-seated CO2
Resumo:
Definition and study of the innovative façade Natura, made of independent pre-vegetated and water storage type panels
Resumo:
In just a few years cloud computing has become a very popular paradigm and a business success story, with storage being one of the key features. To achieve high data availability, cloud storage services rely on replication. In this context, one major challenge is data consistency. In contrast to traditional approaches that are mostly based on strong consistency, many cloud storage services opt for weaker consistency models in order to achieve better availability and performance. This comes at the cost of a high probability of stale data being read, as the replicas involved in the reads may not always have the most recent write. In this paper, we propose a novel approach, named Harmony, which adaptively tunes the consistency level at run-time according to the application requirements. The key idea behind Harmony is an intelligent estimation model of stale reads, allowing to elastically scale up or down the number of replicas involved in read operations to maintain a low (possibly zero) tolerable fraction of stale reads. As a result, Harmony can meet the desired consistency of the applications while achieving good performance. We have implemented Harmony and performed extensive evaluations with the Cassandra cloud storage on Grid?5000 testbed and on Amazon EC2. The results show that Harmony can achieve good performance without exceeding the tolerated number of stale reads. For instance, in contrast to the static eventual consistency used in Cassandra, Harmony reduces the stale data being read by almost 80% while adding only minimal latency. Meanwhile, it improves the throughput of the system by 45% while maintaining the desired consistency requirements of the applications when compared to the strong consistency model in Cassandra.
Resumo:
In professional video production, users have to access to huge multimedia files simultaneously in an error-free environment, this restriction force the use of expensive disk architectures for video servers. Previous researches proposed different RAID systems for each specific task (ingest, editing, file, play-out, etc.). Video production companies have to acquire different servers with different RAIDs systems in order to support each task in the production workflow. The solution has multiples disadvantages, duplicated material in several RAIDs, duplicated material for different qualities, transfer and transcoding processes, etc. In this work, an architecture for video servers based on the spreading of JPEG200 data in different RAIDs is presented, each individual part of the data structure goes to a specific RAID type depending on the effect that produces the data on the overall image quality, the method provide a redundancy correlated with the data rank. The global storage can be used in all the different tasks of the production workflow saving disk space, redundant files and transfers procedures.