Materials Genome in Action: Identifying the Performance Limits of Physical Hydrogen Storage

Science.gov (United States)

2017-01-01

The Materials Genome is in action: the molecular codes for millions of materials have been sequenced, predictive models have been developed, and now the challenge of hydrogen storage is targeted. Renewably generated hydrogen is an attractive transportation fuel with zero carbon emissions, but its storage remains a significant challenge. Nanoporous adsorbents have shown promising physical adsorption of hydrogen approaching targeted capacities, but the scope of studies has remained limited. Here the Nanoporous Materials Genome, containing over 850 000 materials, is analyzed with a variety of computational tools to explore the limits of hydrogen storage. Optimal features that maximize net capacity at room temperature include pore sizes of around 6 Å and void fractions of 0.1, while at cryogenic temperatures pore sizes of 10 Å and void fractions of 0.5 are optimal. Our top candidates are found to be commercially attractive as “cryo-adsorbents”, with promising storage capacities at 77 K and 100 bar with 30% enhancement to 40 g/L, a promising alternative to liquefaction at 20 K and compression at 700 bar. PMID:28413259

Capacity retention in hydrogen storage alloys

Science.gov (United States)

Anani, A.; Visintin, A.; Srinivasan, S.; Appleby, A. J.; Reilly, J. J.; Johnson, J. R.

1992-01-01

Results of our examination of the properties of several candidate materials for hydrogen storage electrodes and their relation to the decrease in H-storage capacity upon open-circuit storage over time are reported. In some of the alloy samples examined to date, only about 10 percent of the hydrogen capacity was lost upon storage for 20 days, while in others, this number was as high as 30 percent for the same period of time. This loss in capacity is attributed to two separate mechanisms: (1) hydrogen desorbed from the electrode due to pressure differences between the cell and the electrode sample; and (2) chemical and/or electrochemical degradation of the alloy electrode upon exposure to the cell environment. The former process is a direct consequence of the equilibrium dissociation pressure of the hydride alloy phase and the partial pressure of hydrogen in the hydride phase in equilibrium with that in the electrolyte environment, while the latter is related to the stability of the alloy phase in the cell environment. Comparison of the equilibrium gas-phase dissociation pressures of these alloys indicate that reversible loss of hydrogen capacity is higher in alloys with P(eqm) greater than 1 atm than in those with P(eqm) less than 1 atm.

46 CFR 112.55-15 - Capacity of storage batteries.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Capacity of storage batteries. 112.55-15 Section 112.55... LIGHTING AND POWER SYSTEMS Storage Battery Installation § 112.55-15 Capacity of storage batteries. (a) A storage battery for an emergency lighting and power system must have the capacity— (1) To close all...

Polyaniline-polypyrrole composites with enhanced hydrogen storage capacities.

Science.gov (United States)

Attia, Nour F; Geckeler, Kurt E

2013-06-13

A facile method for the synthesis of polyaniline-polypyrrole composite materials with network morphology is developed based on polyaniline nanofibers covered by a thin layer of polypyrrole via vapor phase polymerization. The hydrogen storage capacity of the composites is evaluated at room temperature exhibits a twofold increase in hydrogen storage capacity. The HCl-doped polyaniline nanofibers exhibit a storage capacity of 0.46 wt%, whereas the polyaniline-polypyrrole composites could store 0.91 wt% of hydrogen gas. In addition, the effect of the dopant type, counteranion size, and the doping with palladium nanoparticles on the storage properties are also investigated. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The optimal retailer's ordering policies with trade credit financing and limited storage capacity in the supply chain system

Science.gov (United States)

Yen, Ghi-Feng; Chung, Kun-Jen; Chen, Tzung-Ching

2012-11-01

The traditional economic order quantity model assumes that the retailer's storage capacity is unlimited. However, as we all know, the capacity of any warehouse is limited. In practice, there usually exist various factors that induce the decision-maker of the inventory system to order more items than can be held in his/her own warehouse. Therefore, for the decision-maker, it is very practical to determine whether or not to rent other warehouses. In this article, we try to incorporate two levels of trade credit and two separate warehouses (own warehouse and rented warehouse) to establish a new inventory model to help the decision-maker to make the decision. Four theorems are provided to determine the optimal cycle time to generalise some existing articles. Finally, the sensitivity analysis is executed to investigate the effects of the various parameters on ordering policies and annual costs of the inventory system.

Hydrogen storage capacity of titanium met-cars

International Nuclear Information System (INIS)

Akman, N; Durgun, E; Yildirim, T; Ciraci, S

2006-01-01

The adsorption of hydrogen molecules on the titanium metallocarbohedryne (met-car) cluster has been investigated by using the first-principles plane wave method. We have found that, while a single Ti atom at the corner can bind up to three hydrogen molecules, a single Ti atom on the surface of the cluster can bind only one hydrogen molecule. Accordingly, a Ti 8 C 12 met-car can bind up to 16 H 2 molecules and hence can be considered as a high-capacity hydrogen storage medium. Strong interaction between two met-car clusters leading to the dimer formation can affect H 2 storage capacity slightly. Increasing the storage capacity by directly inserting H 2 into the met-car or by functionalizing it with an Na atom have been explored. It is found that the insertion of neither an H 2 molecule nor an Na atom could further promote the H 2 storage capacity of a Ti 8 C 12 cluster. We have also tested the stability of the H 2 -adsorbed Ti 8 C 12 met-car with ab initio molecular dynamics calculations which have been carried out at room temperature

Capacity Expansion Modeling for Storage Technologies

Energy Technology Data Exchange (ETDEWEB)

Hale, Elaine; Stoll, Brady; Mai, Trieu

2017-04-03

The Resource Planning Model (RPM) is a capacity expansion model designed for regional power systems and high levels of renewable generation. Recent extensions capture value-stacking for storage technologies, including batteries and concentrating solar power with storage. After estimating per-unit capacity value and curtailment reduction potential, RPM co-optimizes investment decisions and reduced-form dispatch, accounting for planning reserves; energy value, including arbitrage and curtailment reduction; and three types of operating reserves. Multiple technology cost scenarios are analyzed to determine level of deployment in the Western Interconnection under various conditions.

Have We Overestimated Saline Aquifer CO2 Storage Capacities?

International Nuclear Information System (INIS)

Thibeau, S.; Mucha, V.

2011-01-01

During future, large scale CO 2 geological storage in saline aquifers, fluid pressure is expected to rise as a consequence of CO 2 injection, but the pressure build up will have to stay below specified values to ensure a safe and long term containment of the CO 2 in the storage site. The pressure build up is the result of two different effects. The first effect is a local overpressure around the injectors, which is due to the high CO 2 velocities around the injectors, and which can be mitigated by adding CO 2 injectors. The second effect is a regional scale pressure build up that will take place if the storage aquifer is closed or if the formation water that flows away from the pressurised area is not large enough to compensate volumetrically the CO 2 injection. This second effect cannot be mitigated by adding additional injectors. In the first section of this paper, we review some major global and regional assessments of CO 2 storage capacities in deep saline aquifers, in term of mass and storage efficiency. These storage capacities are primarily based on a volumetric approach: storage capacity is the volumetric sum of the CO 2 that can be stored through various trapping mechanisms. We then discuss in Section 2 storage efficiencies derived from a pressure build up approach, as stated in the CO2STORE final report (Chadwick A. et al. (eds) (2008) Best Practice for the Storage of CO 2 in Saline Aquifers, Observations and Guidelines from the SACS and CO2STORE Projects, Keyworth, Nottingham, BGS Occasional Publication No. 14) and detailed by Van der Meer and Egberts (van der Meer L.G.H., Egberts P.J.P. (2008) A General Method for Calculating Subsurface CO 2 Storage Capacity, OTC Paper 19309, presented at the OTC Conference held in Houston, Texas, USA, 5-8 May). A quantitative range of such storage efficiency is presented, based on a review of orders of magnitudes of pore and water compressibilities and allowable pressure increase. To illustrate the relevance of this

Increasing hydrogen storage capacity using tetrahydrofuran.

Science.gov (United States)

Sugahara, Takeshi; Haag, Joanna C; Prasad, Pinnelli S R; Warntjes, Ashleigh A; Sloan, E Dendy; Sum, Amadeu K; Koh, Carolyn A

2009-10-21

Hydrogen hydrates with tetrahydrofuran (THF) as a promoter molecule are investigated to probe critical unresolved observations regarding cage occupancy and storage capacity. We adopted a new preparation method, mixing solid powdered THF with ice and pressurizing with hydrogen at 70 MPa and 255 +/- 2 K (these formation conditions are insufficient to form pure hydrogen hydrates). All results from Raman microprobe spectroscopy, powder X-ray diffraction, and gas volumetric analysis show a strong dependence of hydrogen storage capacity on THF composition. Contrary to numerous recent reports that claim it is impossible to store H(2) in large cages with promoters, this work shows that, below a THF mole fraction of 0.01, H(2) molecules can occupy the large cages of the THF+H(2) structure II hydrate. As a result, by manipulating the promoter THF content, the hydrogen storage capacity was increased to approximately 3.4 wt % in the THF+H(2) hydrate system. This study shows the tuning effect may be used and developed for future science and practical applications.

Energy efficiency and capacity retention of Ni–MH batteries for storage applications

International Nuclear Information System (INIS)

Zhu, Wenhua H.; Zhu, Ying; Davis, Zenda; Tatarchuk, Bruce J.

2013-01-01

Highlights: ► Ni–MH battery energy efficiency was evaluated at full and partial state-of-charge. ► State-of-charge and state-of-recharge were studied by voltage changes and capacity measurement. ► Capacity retention of the NiMH-B2 battery was 70% after fully charge and 1519 h of storage. ► The inefficient charge process started at ca. 90% of rated capacity when charged at ⩽0.2 C rate. ► Battery durability and low self-discharge strategies are analyzed and discussed for energy storage needs. - Abstract: The Ni–MH batteries were tested for battery energy storage characteristics, including the effects of battery charge or discharge at different rates. The battery energy efficiency and capacity retention were evaluated through measuring the charge/discharge capacities and energies during full and partial state-of-charge (SoC) operations. Energy efficiency results were obtained at various charge input levels and different charge and discharge rates. The inefficient charging process started to take place at ca. 90% state-of-recharge (SoR) when charged at no more than 0.2 C rate. For the NiMH-B2 battery after an approximately full charge (∼100% SoC at 120% SoR and a 0.2 C charge/discharge rate), the capacity retention was obtained as 83% after 360 h of storage, and 70% after 1519 h of storage. The energy efficiency was decreased from 74.0% to 50% after 1519 h of storage time. The Coulomb efficiency was initially 83.34%, and was reduced to 57.95% after 1519 h of storage. The battery has relatively higher energy efficiency at approximately 50% SoC. The energy efficiency was calculated to be more than 92% when the NiMH-C3 battery was charged to 30–70% SoC then discharged to 0% SoC at a 0.2 C charge/discharge rate. In consideration of energy efficiency, charge acceptance, capacity retention rate, and power output needs, as well as Nelson’s analysis on HEV power requirements, the Ni–MH battery is appropriate to work at ca. 50 ± 10% SoC with an

Assessing European capacity for geological storage of carbon dioxide-the EU GeoCapacity project

NARCIS (Netherlands)

Vangkilde-Pedersen, T.; Anthonsen, K.L.; Smith, N.; Kirk, K.; Neele, F.; Meer, B. van der; Le Gallo, Y. le; Bossie-Codreanu, D.; Wojcicki, A.; Nindre, Y.-M. le; Hendriks, C.; Dalhoff, F.; Peter Christensen, N.

2009-01-01

The focus of the GeoCapacity project is GIS mapping of CO2 point sources, infrastructure and geological storage in Europe. The main objective is to assess the European capacity for geological storage of CO2 in deep saline aquifers, oil and gas structures and coal beds. Other priorities are further

A concept of an electricity storage system with 50 MWh storage capacity

Directory of Open Access Journals (Sweden)

Józef Paska

2012-06-01

Full Text Available Electricity storage devices can be divided into indirect storage technology devices (involving electricity conversion into another form of energy, and direct storage (in an electric or magnetic fi eld. Electricity storage technologies include: pumped-storage power plants, BES Battery Energy Storage, CAES Compressed Air Energy Storage, Supercapacitors, FES Flywheel Energy Storage, SMES Superconducting Magnetic Energy Storage, FC Fuel Cells reverse or operated in systems with electrolysers and hydrogen storage. These technologies have diff erent technical characteristics and economic parameters that determine their usability. This paper presents two concepts of an electricity storage tank with a storage capacity of at least 50 MWh, using the BES battery energy storage and CAES compressed air energy storage technologies.

Reracking to increase spent fuel storage capacity

International Nuclear Information System (INIS)

1980-05-01

Many utilities have already increased their spent fuel pool storage capacity by replacing aluminum racks having storage densities as low as 0.2 MTU/ft 2 with stainless steel racks which can more than double storage densities. Use of boron-stainless steel racks or thin stainless steel cans containing reassembled fuel rods allows even higher fuel storage densities (up to approximately 1.25 MTU/ft 2 ). This report evaluates the economics of smaller storage gains that occur if pools, already converted to high density storage, are further reracked

Water storage capacity, stemflow and water funneling in Mediterranean shrubs

Science.gov (United States)

Garcia-Estringana, P.; Alonso-Blázquez, N.; Alegre, J.

2010-08-01

SummaryTo predict water losses and other hydrological and ecological features of a given vegetation, its water storage capacity and stemflow need to be accurately determined. Vast areas of the Mediterranean region are occupied by shrublands yet there is scarce data available on their rainwater interception capacity. In this study, simulated rainfall tests were conducted in controlled conditions on nine Mediterranean shrubs of varying anatomic and morphological features to determine water storage capacity, stemflow and the funneling ratio. After assessing correlations between these hydrological variables and the biometric characteristics of the shrubs, we compared two methods of determining storage capacity: rainfall simulation and immersion. Mean water storage capacity was 1.02 mm (0.35-3.24 mm), stemflow was 16% (3.8-26.4%) and the funneling ratio was 104 (30-260). Per unit biomass, mean storage capacity was 0.66 ml g -1 and ranged from 0.23 ml g -1 for Cistus ladanifer to 2.26 ml g -1 for Lavandula latifolia. Despite their small size, shrubs may generate high water losses to the atmosphere when they form dense communities and this can have a significant impact in regions where water is scarce. When considered the whole shrubs in absolute terms (ml per plant), water storage capacity and stemflow were correlated to biomass and the dendrometric characteristics of the shrubs, yet in relative terms (expressed per surface area unit or as %), anatomic features such as pubescence, branch rigidity or leaf insertion angle emerged as determining factors. The use of a simple procedure to assess storage capacity was inefficient. The immersion method underestimated storage capacity to a different extent for each species. Some shrubs returned high stemflow values typical of their adaptation to the semiarid climate. In contrast, other shrubs seem to have structures that promote stemflow yet have developed other drought-adaptation mechanisms. In this report, we discuss the

Declarative and Procedural Working Memory: Common Principles, Common Capacity Limits?

Directory of Open Access Journals (Sweden)

Klus Oberauer

2010-10-01

Full Text Available Working memory is often described as a system for simultaneous storage and processing. Much research – and most measures of working-memory capacity – focus on the storage component only, that is, people's ability to recall or recognize items after short retention intervals. The mechanisms of processing information are studied in a separate research tradition, concerned with the selection and control of actions in simple choice situations, dual-task constellations, or task-switching setups. both research traditions investigate performance based on representations that are temporarily maintained in an active, highly accessible state, and constrained by capacity limits. In this article an integrated theoretical framework of declarative and procedural working memory is presented that relates the two domains of research to each other. Declarative working memory is proposed to hold representations available for processing (including recall and recognition, whereas procedural working memory holds representations that control processing (i. e., task sets, stimulus-response mappings, and executive control settings. The framework motivates two hypotheses: Declarative and procedural working memory have separate capacity limits, and they operate by analogous principles. The framework also suggests a new characterization of executive functions as the subset of processes governed by procedural working memory that has as its output a change in the conditions of operation of the working-memory system.

Interference and memory capacity limitations.

Science.gov (United States)

Endress, Ansgar D; Szabó, Szilárd

2017-10-01

Working memory (WM) is thought to have a fixed and limited capacity. However, the origins of these capacity limitations are debated, and generally attributed to active, attentional processes. Here, we show that the existence of interference among items in memory mathematically guarantees fixed and limited capacity limits under very general conditions, irrespective of any processing assumptions. Assuming that interference (a) increases with the number of interfering items and (b) brings memory performance to chance levels for large numbers of interfering items, capacity limits are a simple function of the relative influence of memorization and interference. In contrast, we show that time-based memory limitations do not lead to fixed memory capacity limitations that are independent of the timing properties of an experiment. We show that interference can mimic both slot-like and continuous resource-like memory limitations, suggesting that these types of memory performance might not be as different as commonly believed. We speculate that slot-like WM limitations might arise from crowding-like phenomena in memory when participants have to retrieve items. Further, based on earlier research on parallel attention and enumeration, we suggest that crowding-like phenomena might be a common reason for the 3 major cognitive capacity limitations. As suggested by Miller (1956) and Cowan (2001), these capacity limitations might arise because of a common reason, even though they likely rely on distinct processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Economic performance of water storage capacity expansion for food security

Science.gov (United States)

Gohar, Abdelaziz A.; Ward, Frank A.; Amer, Saud A.

2013-03-01

SummaryContinued climate variability, population growth, and rising food prices present ongoing challenges for achieving food and water security in poor countries that lack adequate water infrastructure. Undeveloped storage infrastructure presents a special challenge in northern Afghanistan, where food security is undermined by highly variable water supplies, inefficient water allocation rules, and a damaged irrigation system due three decades of war and conflict. Little peer-reviewed research to date has analyzed the economic benefits of water storage capacity expansions as a mechanism to sustain food security over long periods of variable climate and growing food demands needed to feed growing populations. This paper develops and applies an integrated water resources management framework that analyzes impacts of storage capacity expansions for sustaining farm income and food security in the face of highly fluctuating water supplies. Findings illustrate that in Afghanistan's Balkh Basin, total farm income and food security from crop irrigation increase, but at a declining rate as water storage capacity increases from zero to an amount equal to six times the basin's long term water supply. Total farm income increases by 21%, 41%, and 42% for small, medium, and large reservoir capacity, respectively, compared to the existing irrigation system unassisted by reservoir storage capacity. Results provide a framework to target water infrastructure investments that improve food security for river basins in the world's dry regions with low existing storage capacity that face ongoing climate variability and increased demands for food security for growing populations.

Working memory is not fixed-capacity: More active storage capacity for real-world objects than for simple stimuli.

Science.gov (United States)

Brady, Timothy F; Störmer, Viola S; Alvarez, George A

2016-07-05

Visual working memory is the cognitive system that holds visual information active to make it resistant to interference from new perceptual input. Information about simple stimuli-colors and orientations-is encoded into working memory rapidly: In under 100 ms, working memory ‟fills up," revealing a stark capacity limit. However, for real-world objects, the same behavioral limits do not hold: With increasing encoding time, people store more real-world objects and do so with more detail. This boost in performance for real-world objects is generally assumed to reflect the use of a separate episodic long-term memory system, rather than working memory. Here we show that this behavioral increase in capacity with real-world objects is not solely due to the use of separate episodic long-term memory systems. In particular, we show that this increase is a result of active storage in working memory, as shown by directly measuring neural activity during the delay period of a working memory task using EEG. These data challenge fixed-capacity working memory models and demonstrate that working memory and its capacity limitations are dependent upon our existing knowledge.

Efficient Control of Energy Storage for Increasing the PV Hosting Capacity of LV Grids

DEFF Research Database (Denmark)

Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob

2016-01-01

grid is usually limited by overvoltage, and the efficient control of distributed electrical energy storage systems (EESSs) can considerably increase this capacity. In this paper, a new control approach based on the voltage sensitivity analysis is proposed to prevent overvoltage and increase the PV......Photovoltaic (PV) systems are among the renewable sources that electrical energy systems are adopting with increasing frequency. The majority of already-installed PV systems are decentralized units that are usually connected to lowvoltage (LV) distribution grids. The PV hosting capacity of an LV...... hosting capacity of LV grids by determining dynamic set points for EESS management. The method has the effectiveness of central control methods and can effectively decrease the energy storage required for overvoltage prevention, yet it eliminates the need for a broadband and fast communication. The net...

Prospects and Limits of Energy Storage in Batteries.

Science.gov (United States)

Abraham, K M

2015-03-05

Energy densities of Li ion batteries, limited by the capacities of cathode materials, must increase by a factor of 2 or more to give all-electric automobiles a 300 mile driving range on a single charge. Battery chemical couples with very low equivalent weights have to be sought to produce such batteries. Advanced Li ion batteries may not be able to meet this challenge in the near term. The state-of-the-art of Li ion batteries is discussed, and the challenges of developing ultrahigh energy density rechargeable batteries are identified. Examples of ultrahigh energy density battery chemical couples include Li/O2, Li/S, Li/metal halide, and Li/metal oxide systems. Future efforts are also expected to involve all-solid-state batteries with performance similar to their liquid electrolyte counterparts, biodegradable batteries to address environmental challenges, and low-cost long cycle-life batteries for large-scale energy storage. Ultimately, energy densities of electrochemical energy storage systems are limited by chemistry constraints.

Rocky Mountain Regional CO{sub 2} Storage Capacity and Significance

Energy Technology Data Exchange (ETDEWEB)

Laes, Denise; Eisinger, Chris; Esser, Richard; Morgan, Craig; Rauzi, Steve; Scholle, Dana; Matthews, Vince; McPherson, Brian

2013-08-30

The purpose of this study includes extensive characterization of the most promising geologic CO{sub 2} storage formations on the Colorado Plateau, including estimates of maximum possible storage capacity. The primary targets of characterization and capacity analysis include the Cretaceous Dakota Formation, the Jurassic Entrada Formation and the Permian Weber Formation and their equivalents in the Colorado Plateau region. The total CO{sub 2} capacity estimates for the deep saline formations of the Colorado Plateau region range between 9.8 metric GT and 143 metric GT, depending on assumed storage efficiency, formations included, and other factors.

Beyond peak reservoir storage? A global estimate of declining water storage capacity in large reservoirs

NARCIS (Netherlands)

Wisser, D.; Frolking, S.; Hagen, Stephen; Bierkens, M.F.P.|info:eu-repo/dai/nl/125022794

2013-01-01

Water storage is an important way to cope with temporal variation in water supply anddemand. The storage capacity and the lifetime of water storage reservoirs can besignificantly reduced by the inflow of sediments. A global, spatially explicit assessment ofreservoir storage loss in conjunction with

Storage capacity of hydrogen in gas hydrates

International Nuclear Information System (INIS)

Tsuda, Takaaki; Ogata, Kyohei; Hashimoto, Shunsuke; Sugahara, Takeshi; Sato, Hiroshi; Ohgaki, Kazunari

2010-01-01

The storage capacity of H 2 in the THF, THT, and furan hydrates was studied by p-V-T measurements. We confirmed that the storage and release processes of H 2 in all hydrates could be performed reversibly by pressure swing without destroying of hydrate cages. H 2 absorption in both THT and furan hydrates is much faster than THF hydrate in spite of same unit-cell structure. On the other hand, the storage amounts of H 2 are coincident in the all additive hydrates and would reach at about 1.0 mass% asymptotically.

Required storage capacity to increase the value of renewable energy

International Nuclear Information System (INIS)

Nacht, T.

2014-01-01

The effort to achieve a more eco - friendly production of energy leads to larger shares of renewables in the electricity sector, resulting in more supply - dependency and volatility. This results in a time shift between production and consumption. In order to gain an upper hand, possibilities for transferring renewable energies from the time of production to the time when the demand occurs are researched. Energy storage systems will play a big role in this process, with pumped storage plants being the most developed and most common technology nowadays. As a first part of this thesis, the renewables in Germany are studied through the use of models on the basis of hourly measured values of the primary energy carriers for the corresponding technology. For these data series many years’ worth of measurements were considered, resulting in data for the hourly production values of the renewable energy sources. The results show a strong dependency between production and the seasons of the year. Furthermore a very small secured contribution of renewable production during times of peak load is registered, leading to the conclusion that energy storages are indeed necessary. Different strategies for the dispatch of the storage technologies pumped hydro storage, compressed air storage and hydrogen storage are developed for the region of Germany, which will be dispatched outside the energy - only market. The different strategies for the storage dispatch have the reduction of the resulting load in common, by preferably transferring renewable energy from times when it is not needed to those times with high loads. This resulting load needs to be covered by thermal power plants. The required capacities of the different storage technologies are evaluated and compared. By using pumped storage plants the increase in the value of renewables, as measured by the secure contribution during peak load hours, is determined. An analysis of different compositions of renewable production allows

Soil Phosphorus Storage Capacity for Environmental Risk Assessment

Directory of Open Access Journals (Sweden)

Vimala D. Nair

2014-01-01

Full Text Available Reliable techniques must be developed to predict phosphorus (P storage and release from soils of uplands, ditches, streams, and wetlands in order to better understand the natural, anthropogenic, and legacy sources of P and their impact on water quality at a field/plot as well as larger scales. A concept called the “safe” soil phosphorus storage capacity (SPSC that is based on a threshold phosphorus saturation ratio (PSR has been developed; the PSR is the molar ratio of P to Fe and Al, and SPSC is a PSR-based calculation of the remaining soil P storage capacity that captures risks arising from previous loading as well as inherently low P sorption capacity of a soil. Zero SPSC amounts to a threshold value below which P runoff or leaching risk increases precipitously. In addition to the use of the PSR/SPSC concept for P risk assessment and management, and its ability to predict isotherm parameters such as the Langmuir strength of bonding, KL, and the equilibrium P concentration, EPC0, this simple, cost-effective, and quantitative approach has the potential to be used as an agronomic tool for more precise application of P for plant uptake.

Parametric Study on the Dynamic Heat Storage Capacity of Building Elements

DEFF Research Database (Denmark)

Artmann, Nikolai; Manz, H.; Heiselberg, Per

2007-01-01

as their interrelation. The potential of increasing thermal mass by using phase change materials (PCM) was estimated assuming increased thermal capacity. The results show a significant impact of the heat transfer coefficient on heat storage capacity, especially for thick, thermally heavy elements. The storage capacity...... of onedimensional heat conduction in a slab with convective boundary condition was applied to quantify the dynamic heat storage capacity of a particular building element. The impact of different parameters, such as slab thickness, material properties and the heat transfer coefficient was investigated, as well......In modern, extensively glazed office buildings, due to high solar and internal loads and increased comfort expectations, air conditioning systems are often used even in moderate and cold climates. Particularly in this case, passive cooling by night-time ventilation seems to offer considerable...

Subgrid Parameterization of the Soil Moisture Storage Capacity for a Distributed Rainfall-Runoff Model

Directory of Open Access Journals (Sweden)

Weijian Guo

2015-05-01

Full Text Available Spatial variability plays an important role in nonlinear hydrologic processes. Due to the limitation of computational efficiency and data resolution, subgrid variability is usually assumed to be uniform for most grid-based rainfall-runoff models, which leads to the scale-dependence of model performances. In this paper, the scale effect on the Grid-Xinanjiang model was examined. The bias of the estimation of precipitation, runoff, evapotranspiration and soil moisture at the different grid scales, along with the scale-dependence of the effective parameters, highlights the importance of well representing the subgrid variability. This paper presents a subgrid parameterization method to incorporate the subgrid variability of the soil storage capacity, which is a key variable that controls runoff generation and partitioning in the Grid-Xinanjiang model. In light of the similar spatial pattern and physical basis, the soil storage capacity is correlated with the topographic index, whose spatial distribution can more readily be measured. A beta distribution is introduced to represent the spatial distribution of the soil storage capacity within the grid. The results derived from the Yanduhe Basin show that the proposed subgrid parameterization method can effectively correct the watershed soil storage capacity curve. Compared to the original Grid-Xinanjiang model, the model performances are quite consistent at the different grid scales when the subgrid variability is incorporated. This subgrid parameterization method reduces the recalibration necessity when the Digital Elevation Model (DEM resolution is changed. Moreover, it improves the potential for the application of the distributed model in the ungauged basin.

Storage capacity and retrieval time of small-world neural networks

International Nuclear Information System (INIS)

Oshima, Hiraku; Odagaki, Takashi

2007-01-01

To understand the influence of structure on the function of neural networks, we study the storage capacity and the retrieval time of Hopfield-type neural networks for four network structures: regular, small world, random networks generated by the Watts-Strogatz (WS) model, and the same network as the neural network of the nematode Caenorhabditis elegans. Using computer simulations, we find that (1) as the randomness of network is increased, its storage capacity is enhanced; (2) the retrieval time of WS networks does not depend on the network structure, but the retrieval time of C. elegans's neural network is longer than that of WS networks; (3) the storage capacity of the C. elegans network is smaller than that of networks generated by the WS model, though the neural network of C. elegans is considered to be a small-world network

The EPQ model under conditions of two levels of trade credit and limited storage capacity in supply chain management

Science.gov (United States)

Chung, Kun-Jen

2013-09-01

An inventory problem involves a lot of factors influencing inventory decisions. To understand it, the traditional economic production quantity (EPQ) model plays rather important role for inventory analysis. Although the traditional EPQ models are still widely used in industry, practitioners frequently question validities of assumptions of these models such that their use encounters challenges and difficulties. So, this article tries to present a new inventory model by considering two levels of trade credit, finite replenishment rate and limited storage capacity together to relax the basic assumptions of the traditional EPQ model to improve the environment of the use of it. Keeping in mind cost-minimisation strategy, four easy-to-use theorems are developed to characterise the optimal solution. Finally, the sensitivity analyses are executed to investigate the effects of the various parameters on ordering policies and the annual total relevant costs of the inventory system.

Estimation of energy storage capacity in power system in japan under future demand and supply factors

International Nuclear Information System (INIS)

Kurihara, Ikuo; Tanaka, Toshikatsu

1996-01-01

The desirable capacity of future energy storage facility in power system in Japan is discussed in this paper, putting emphasis on future new electric demand/supply factors such as CO 2 emission problems and social structure change. The two fundamental demand scenarios are considered; one is base case scenario which extrapolates the trend until now and the other is social structure change scenario. The desirable capacity of the energy storage facility is obtained from the result of optimum generation mix which minimizes the yearly expenses of the target year (2030 and 2050). The result shows that the optimum capacity of energy storage facility is about 10 to 15%. The social structure change and demand side energy storage have great influences on the optimum capacity of supply side storage. The former increases storage capacity. The latter reduces it and also contributes to the reduction of generation cost. Suppression of CO 2 emission basically affects to reduce the storage capacity. The load following operation of nuclear plant also reduces the optimum storage capacity in the case it produces surplus energy at night. Though there exist many factors which increase or decrease the capacity of energy storage facility, as a whole, it is concluded that the development of new energy storage technology is necessary for future. (author)

A thermal storage capacity market for non dispatchable renewable energies

Science.gov (United States)

Bennouna, El Ghali; Mouaky, Ammar; Arrad, Mouad; Ghennioui, Abdellatif; Mimet, Abdelaziz

2017-06-01

Due to the increasingly high capacity of wind power and solar PV in Germany and some other European countries and the high share of variable renewable energy resources in comparison to fossil and nuclear capacity, a power reserve market structured by auction systems was created to facilitate the exchange of balance power capacities between systems and even grid operators. Morocco has a large potential for both wind and solar energy and is engaged in a program to deploy 2000MW of wind capacity by 2020 and 3000 MW of solar capacity by 2030. Although the competitiveness of wind energy is very strong, it appears clearly that the wind program could be even more ambitious than what it is, especially when compared to the large exploitable potential. On the other hand, heavy investments on concentrated solar power plants equipped with thermal energy storage have triggered a few years ago including the launching of the first part of the Nour Ouarzazate complex, the goal being to reach stable, dispatchable and affordable electricity especially during evening peak hours. This paper aims to demonstrate the potential of shared thermal storage capacity between dispatchable and non dispatchable renewable energies and particularly CSP and wind power. Thus highlighting the importance of a storage capacity market in parallel to the power reserve market and the and how it could enhance the development of both wind and CSP market penetration.

Operational limits of a three level neutral point clamped converter used for controlling a hybrid energy storage system

International Nuclear Information System (INIS)

Etxeberria, A.; Vechiu, I.; Camblong, H.; Kreckelbergh, S.; Bacha, S.

2014-01-01

Highlights: • The control of a hybrid storage system using a Three Level NPC converter is analysed. • A sinusoidal PWM with an offset injection is used to control the storage system. • The operation of the selected converter is analysed in its entire operation range. • The operational limits of the Three Level NPC converter are defined. - Abstract: This work analyses the use of a Three-Level Neutral Point Clamped (3LNPC) converter to control the power flow of a Hybrid Energy Storage System (HESS) and at the same time interconnect it with the common AC bus of a microgrid. Nowadays there is not any storage technology capable of offering a high energy storage capacity, a high power capacity and a fast response at the same time. Therefore, the necessity of hybridising more than one storage technology is a widely accepted idea in order to satisfy the mentioned requirements. This work shows how the operational limits of the 3LNPC converter can be calculated and integrated in a control structure to facilitate an optimal use of the HESS according to the rules fixed by the user

Reducing a cortical network to a Potts model yields storage capacity estimates

Science.gov (United States)

Naim, Michelangelo; Boboeva, Vezha; Kang, Chol Jun; Treves, Alessandro

2018-04-01

An autoassociative network of Potts units, coupled via tensor connections, has been proposed and analysed as an effective model of an extensive cortical network with distinct short- and long-range synaptic connections, but it has not been clarified in what sense it can be regarded as an effective model. We draw here the correspondence between the two, which indicates the need to introduce a local feedback term in the reduced model, i.e. in the Potts network. An effective model allows the study of phase transitions. As an example, we study the storage capacity of the Potts network with this additional term, the local feedback w, which contributes to drive the activity of the network towards one of the stored patterns. The storage capacity calculation, performed using replica tools, is limited to fully connected networks, for which a Hamiltonian can be defined. To extend the results to the case of intermediate partial connectivity, we also derive the self-consistent signal-to-noise analysis for the Potts network; and finally we discuss the implications for semantic memory in humans.

Assessing materials handling and storage capacities in port terminals

Science.gov (United States)

Dinu, O.; Roşca, E.; Popa, M.; Roşca, M. A.; Rusca, A.

2017-08-01

Terminals constitute the factual interface between different modes and, as a result, buffer stocks are unavoidable whenever transport flows with different discontinuities meet. This is the reason why assessing materials handling and storage capacities is an important issue in the course of attempting to increase operative planning of logistic processes in terminals. Proposed paper starts with a brief review of the compatibilities between different sorts of materials and corresponding transport modes and after, a literature overview of the studies related to ports terminals and their specialization is made. As a methodology, discrete event simulation stands as a feasible technique for assessing handling and storage capacities at the terminal, taking into consideration the multi-flows interaction and the non-uniform arrivals of vessels and inland vehicles. In this context, a simulation model, that integrates the activities of an inland water terminal and describes the essential interactions between the subsystems which influence the terminal capacity, is developed. Different scenarios are simulated for diverse sorts of materials, leading to bottlenecks identification, performance indicators such as average storage occupancy rate, average dwell or transit times estimations, and their evolution is analysed in order to improve the transfer operations in the logistic process

Study on increasing spent fuel storage capacity at Juragua NPP

International Nuclear Information System (INIS)

Guerra Valdes, R.; Lopez Aldama, D.; Rodriguez Gual, M.; Garcia Yip, F.

1999-01-01

The delay in decision about the final disposal of the spent fuel, led to longer interim storage. The reracking og the storage pools was an economical and feasible option to increase the storage capacity on the site. Reracking of the storage facility led to the analysis of the new conditions for criticality, shielding, residual heat removal and mechanical loads over the structures. This paper includes a summary of the studies on criticality and dose rate changes in the vicinity of the storage pool of Juragua NPP

Achieving increased spent fuel storage capacity at the High Flux Isotope Reactor (HFIR)

International Nuclear Information System (INIS)

Cook, D.H.; Chang, S.J.; Dabs, R.D.; Freels, J.D.; Morgan, K.A.; Rothrock, R.B.; Griess, J.C.

1994-01-01

The HFIR facility was originally designed to store approximately 25 spent cores, sufficient to allow for operational contingencies and for cooling prior to off-site shipment for reprocessing. The original capacity has now been increased to 60 positions, of which 53 are currently filled (September 1994). Additional spent cores are produced at a rate of about 10 or 11 per year. Continued HFIR operation, therefore, depends on a significant near-term expansion of the pool storage capacity, as well as on a future capability of reprocessing or other storage alternatives once the practical capacity of the pool is reached. To store the much larger inventory of spent fuel that may remain on-site under various future scenarios, the pool capacity is being increased in a phased manner through installation of a new multi-tier spent fuel rack design for higher density storage. A total of 143 positions was used for this paper as the maximum practical pool capacity without impacting operations; however, greater ultimate capacities were addressed in the supporting analyses and approval documents. This paper addresses issues related to the pool storage expansion including (1) seismic effects on the three-tier storage arrays, (2) thermal performance of the new arrays, (3) spent fuel cladding corrosion concerns related to the longer period of pool storage, and (4) impacts of increased spent fuel inventory on the pool water quality, water treatment systems, and LLLW volume

Consensus based scheduling of storage capacities in a virtual microgrid

DEFF Research Database (Denmark)

Brehm, Robert; Top, Søren; Mátéfi-Tempfli, Stefan

2017-01-01

We present a distributed, decentralized method for coordinated scheduling of charge/discharge intervals of storage capacities in a utility grid integrated microgrid. The decentralized algorithm is based on a consensus scheme and solves an optimisation problem with the objective of minimising......, by use of storage capacities, the power flow over a transformer substation from/to the utility grid integrated microgrid. It is shown that when using this coordinated scheduling algorithm, load profile flattening (peak-shaving) for the utility grid is achieved. Additionally, mutual charge...

Influence of Distributed Residential Energy Storage on Voltage in Rural Distribution Network and Capacity Configuration

Science.gov (United States)

Liu, Lu; Tong, Yibin; Zhao, Zhigang; Zhang, Xuefen

2018-03-01

Large-scale access of distributed residential photovoltaic (PV) in rural areas has solved the voltage problem to a certain extent. However, due to the intermittency of PV and the particularity of rural residents’ power load, the problem of low voltage in the evening peak remains to be resolved. This paper proposes to solve the problem by accessing residential energy storage. Firstly, the influence of access location and capacity of energy storage on voltage distribution in rural distribution network is analyzed. Secondly, the relation between the storage capacity and load capacity is deduced for four typical load and energy storage cases when the voltage deviation meets the demand. Finally, the optimal storage position and capacity are obtained by using PSO and power flow simulation.

Visual long-term memory has a massive storage capacity for object details.

Science.gov (United States)

Brady, Timothy F; Konkle, Talia; Alvarez, George A; Oliva, Aude

2008-09-23

One of the major lessons of memory research has been that human memory is fallible, imprecise, and subject to interference. Thus, although observers can remember thousands of images, it is widely assumed that these memories lack detail. Contrary to this assumption, here we show that long-term memory is capable of storing a massive number of objects with details from the image. Participants viewed pictures of 2,500 objects over the course of 5.5 h. Afterward, they were shown pairs of images and indicated which of the two they had seen. The previously viewed item could be paired with either an object from a novel category, an object of the same basic-level category, or the same object in a different state or pose. Performance in each of these conditions was remarkably high (92%, 88%, and 87%, respectively), suggesting that participants successfully maintained detailed representations of thousands of images. These results have implications for cognitive models, in which capacity limitations impose a primary computational constraint (e.g., models of object recognition), and pose a challenge to neural models of memory storage and retrieval, which must be able to account for such a large and detailed storage capacity.

Spent fuel storage capacities. An update of DOE/RL-84-1

International Nuclear Information System (INIS)

1985-10-01

Spent fuel storage capacities at some commercial light water reactors (LWRs) are inadequate to handle projected spent fuel discharges. This report presents estimates of potential near-term requirements for additional LWR spent fuel storage capacity, based on information supplied by utilities operating commercial nuclear power plants. These estimates provide information needed for planning the Department of Energy's (DOE) activities to be carried out under the DOE's Commercial Spent Fuel Management (CSFM) Program, in conjunction with the requirements of the Nuclear Waste Policy Act of 1982. The estimates in this report cover the period from the present through the year 2000. Although the DOE objective is to begin accepting spent fuel for final disposal in 1998, types of fuel and the receipt rates to be shipped are not yet known. Hence, this report makes no assumption regarding such fuel shipments. The resport also assesses the possible impacts of increased fuel exposure and spent fuel transhipment on the requirements for additional storage capacity

Storage capacity of attractor neural networks with depressing synapses

International Nuclear Information System (INIS)

Torres, Joaquin J.; Pantic, Lovorka; Kappen, Hilbert J.

2002-01-01

We compute the capacity of a binary neural network with dynamic depressing synapses to store and retrieve an infinite number of patterns. We use a biologically motivated model of synaptic depression and a standard mean-field approach. We find that at T=0 the critical storage capacity decreases with the degree of the depression. We confirm the validity of our main mean-field results with numerical simulations

The storage capacity of cocoa seeds (Theobroma cacao L.) through giving Polyethylene Glycol (PEG) in the various of storage container

Science.gov (United States)

Lahay, R. R.; Misrun, S.; Sipayung, R.

2018-02-01

Cocoa is plant which it’s seed character is recalcitrant. Giving PEG and using various of storage containers was hoped to increase storage capacity of cocoa seeds as long as period of saving. The reseach was aimed to identify the storage capacity of cocoa seeds through giving PEG in the various of storage containers. Research took place in Hataram Jawa II, Kabupaten Simalungun, Propinsi Sumatera Utara, Indonesia. The method of this research is spit-split plot design with 3 replication. Storage period was put on main plot which was consisted of 4 level, PEG concentration was put on sub plot, consisted of 4 level and storage container was put on the sub sub plot consisted of 3 types. The results showed that until 4 days at storage with 45 % PEG concentration at all storage container, percentage of seed germination at storage can be decreased to be 2.90 %, and can be defensed until 16 days with 45 % PEG concentration at perforated plastic storage container. Percentage of molded seeds and seed moisture content were increased with added period of storage but seed moisture content was increased until 12 days at storage and was decreased at 16 days in storage.

Effects of thinning intensities on soil infiltration and water storage capacity in a Chinese pine-oak mixed forest.

Science.gov (United States)

Chen, Lili; Yuan, Zhiyou; Shao, Hongbo; Wang, Dexiang; Mu, Xingmin

2014-01-01

Thinning is a crucial practice in the forest ecosystem management. The soil infiltration rate and water storage capacity of pine-oak mixed forest under three different thinning intensity treatments (15%, 30%, and 60%) were studied in Qinling Mountains of China. The thinning operations had a significant influence on soil infiltration rate and water storage capacity. The soil infiltration rate and water storage capacity in different thinning treatments followed the order of control (nonthinning): soil infiltration rate and water storage capacity of pine-oak mixed forest in Qinling Mountains. The soil initial infiltration rate, stable infiltration rate, and average infiltration rate in thinning 30% treatment were significantly increased by 21.1%, 104.6%, and 60.9%, compared with the control. The soil maximal water storage capacity and noncapillary water storage capacity in thinning 30% treatment were significantly improved by 20.1% and 34.3% in contrast to the control. The soil infiltration rate and water storage capacity were significantly higher in the surface layer (0~20 cm) than in the deep layers (20~40 cm and 40~60 cm). We found that the soil property was closely related to soil infiltration rate and water storage capacity.

High-Capacity Hydrogen-Based Green-Energy Storage Solutions For The Grid Balancing

Science.gov (United States)

D'Errico, F.; Screnci, A.

One of the current main challenges in green-power storage and smart grids is the lack of effective solutions for accommodating the unbalance between renewable energy sources, that offer intermittent electricity supply, and a variable electricity demand. Energy management systems have to be foreseen for the near future, while they still represent a major challenge. Integrating intermittent renewable energy sources, by safe and cost-effective energy storage systems based on solid state hydrogen is today achievable thanks to recently some technology breakthroughs. Optimized solid storage method made of magnesium-based hydrides guarantees a very rapid absorption and desorption kinetics. Coupled with electrolyzer technology, high-capacity storage of green-hydrogen is therefore practicable. Besides these aspects, magnesium has been emerging as environmentally friend energy storage method to sustain integration, monitoring and control of large quantity of GWh from high capacity renewable generation in the EU.

Evolution of antioxidant capacity during storage of selected fruits and vegetables.

Science.gov (United States)

Kevers, Claire; Falkowski, Michael; Tabart, Jessica; Defraigne, Jean-Olivier; Dommes, Jacques; Pincemail, Joël

2007-10-17

Interest in the consumption of fresh fruits and vegetables is, to a large extent, due to its content of bioactive nutrients and their importance as dietary antioxidants. Among all of the selected fruits and vegetables, strawberries and black grapes have relatively high antioxidant capacities associated with high contents of total phenolic compounds, ascorbic acid, and flavonols. More interesting, the results of this study indicated that in most fruits and vegetables storage did not affect negatively the antioxidant capacity. Better, in some cases, an increase of the antioxidant capacity was observed in the days following their purchase, accompanied by an increase in phenolic compounds. In general, fruits and vegetables visually spoil before any significant antioxidant capacity loss occurs except in banana and broccoli. When ascorbic acid or flavonoids (aglycons of flavonols and anthocyanins) were concerned, the conclusions were similar. Their content was generally stable during storage.

Development and evaluation of a low-cost and high-capacity DICOM image data storage system for research.

Science.gov (United States)

Yakami, Masahiro; Ishizu, Koichi; Kubo, Takeshi; Okada, Tomohisa; Togashi, Kaori

2011-04-01

Thin-slice CT data, useful for clinical diagnosis and research, is now widely available but is typically discarded in many institutions, after a short period of time due to data storage capacity limitations. We designed and built a low-cost high-capacity Digital Imaging and COmmunication in Medicine (DICOM) storage system able to store thin-slice image data for years, using off-the-shelf consumer hardware components, such as a Macintosh computer, a Windows PC, and network-attached storage units. "Ordinary" hierarchical file systems, instead of a centralized data management system such as relational database, were adopted to manage patient DICOM files by arranging them in directories enabling quick and easy access to the DICOM files of each study by following the directory trees with Windows Explorer via study date and patient ID. Software used for this system was open-source OsiriX and additional programs we developed ourselves, both of which were freely available via the Internet. The initial cost of this system was about $3,600 with an incremental storage cost of about $900 per 1 terabyte (TB). This system has been running since 7th Feb 2008 with the data stored increasing at the rate of about 1.3 TB per month. Total data stored was 21.3 TB on 23rd June 2009. The maintenance workload was found to be about 30 to 60 min once every 2 weeks. In conclusion, this newly developed DICOM storage system is useful for research due to its cost-effectiveness, enormous capacity, high scalability, sufficient reliability, and easy data access.

Cycloaddition in peptides for high-capacity optical storage

DEFF Research Database (Denmark)

Lohse, Brian; Berg, Rolf Henrik; Hvilsted, Søren

2006-01-01

Photodimerization of chromophores attached to a short peptide chain is investigated for high-capacity optical digital storage with UV lasers. The length and rigidity of the peptide chain assure an optimal distance and orientation of the chromophores for effective photodimerization. Using a theory...... developed by Tomlinson, the absorption cross section for the dimerization process in a uracil-ornithine-based hexamer is determined to be 9 x 10(-20) cm(2). A large change in the transmission due to irradiation in the UV area may make it possible to realize multilevel storage in a thin film of the peptides....

Melton Valley Storage Tanks Capacity Increase Project, Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1995-04-01

The US Department of Energy (DOE) proposes to construct and maintain additional storage capacity at Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee, for liquid low-level radioactive waste (LLLW). New capacity would be provided by a facility partitioned into six individual tank vaults containing one 100,000 gallon LLLW storage tank each. The storage tanks would be located within the existing Melton Valley Storage Tank (MVST) facility. This action would require the extension of a potable water line approximately one mile from the High Flux Isotope Reactor (HFIR) area to the proposed site to provide the necessary potable water for the facility including fire protection. Alternatives considered include no-action, cease generation, storage at other ORR storage facilities, source treatment, pretreatment, and storage at other DOE facilities

The Potential for Energy Storage to Provide Peaking Capacity in California under Increased Penetration of Solar Photovoltaics: Report Summary

Energy Technology Data Exchange (ETDEWEB)

Denholm, Paul L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-03-12

Opportunities to provide peaking capacity with low-cost energy storage are emerging. But adding storage changes the ability of subsequent storage additions to meet peak demand. Increasing photovoltaic (PV) deployment also affects storage's ability to provide peak capacity. This study examines storage's potential to replace conventional peak capacity in California.

A first-principles study of hydrogen storage capacity based on Li-Na-decorated silicene.

Science.gov (United States)

Sheng, Zhe; Wu, Shujing; Dai, Xianying; Zhao, Tianlong; Hao, Yue

2018-05-23

Surface decoration with alkali metal adatoms has been predicted to be promising for silicene to obtain high hydrogen storage capacity. Herein, we performed a detailed study of the hydrogen storage properties of Li and Na co-decorated silicene (Li-Na-decorated silicene) based on first-principles calculations using van der Waals correction. The hydrogen adsorption behaviors, including the adsorption order, the maximum capacity, and the corresponding mechanism were analyzed in detail. Our calculations show that up to three hydrogen molecules can firmly bind to each Li atom and six for each Na atom, respectively. The hydrogen storage capacity is estimated to be as high as 6.65 wt% with a desirable average adsorption energy of 0.29 eV/H2. It is confirmed that both the charge-induced electrostatic interaction and the orbital hybridizations play a great role in hydrogen storage. Our results may enhance our fundamental understanding of the hydrogen storage mechanism, which is of great importance for the practical application of Li-Na-decorated silicene in hydrogen storage.

Canopy storage capacity and wettability of leaves and needles: The effect of water temperature changes

Science.gov (United States)

Klamerus-Iwan, Anna; Błońska, Ewa

2018-04-01

The canopy storage capacity (S) is a major component of the surface water balance. We analysed the relationship between the tree canopy water storage capacity and leaf wettability under changing simulated rainfall temperature. We estimated the effect of the rain temperature change on the canopy storage capacity and contact angle of leave and needle surfaces based on two scenarios. Six dominant forest trees were analysed: English oak (Quercus roburL.), common beech (Fagus sylvatica L.), small-leaved lime (Tilia cordata Mill), silver fir (Abies alba), Scots pine (Pinus sylvestris L.),and Norway spruce (Picea abies L.). Twigs of these species were collected from Krynica Zdrój, that is, the Experimental Forestry unit of the University of Agriculture in Cracow (southern Poland). Experimental analyses (simulations of precipitation) were performed in a laboratory under controlled conditions. The canopy storage capacity and leaf wettability classification were determined at 12 water temperatures and a practical calculator to compute changes of S and contact angles of droplets was developed. Among all species, an increase of the rainfall temperature by 0.7 °C decreases the contact angle between leave and needle surfaces by 2.41° and increases the canopy storage capacity by 0.74 g g-1; an increase of the rain temperature by 2.7 °C decreases the contact angle by 9.29° and increases the canopy storage capacity by 2.85 g g-1. A decreased contact angle between a water droplet and leaf surface indicates increased wettability. Thus, our results show that an increased temperature increases the leaf wettability in all examined species. The comparison of different species implies that the water temperature has the strongest effect on spruce and the weakest effect on oak. These data indicate that the rainfall temperature influences the canopy storage capacity.

Surface water storage capacity of twenty tree species in Davis, California

Science.gov (United States)

Qingfu Xiao; E. Gregory. McPherson

2016-01-01

Urban forestry is an important green infrastructure strategy because healthy trees can intercept rainfall, reducing stormwater runoff and pollutant loading. Surface saturation storage capacity, defined as the thin film of water that must wet tree surfaces before flow begins, is the most important variable influencing rainfall interception processes. Surface storage...

Storage capacity of multi-layered neural networks with binary weights

International Nuclear Information System (INIS)

Tarkowski, W.; Hemmen, J.L. van

1997-01-01

Using statistical physics methods we investigate two-layered perceptrons which consist of N binary input neurons, K hidden units and a single output node. Four basic types of such networks are considered: the so-called Committee, Parity, and AND Machines which makes a decision based on a majority, parity, and the logical AND rules, respectively (for these cases the weights that connect hidden units and output node are taken to be equal to one), and the General Machine where one allows all the synaptic couplings to vary. For these kinds of network we examine two types of architecture: fully connected and three-connected ones (with overlapping and non-overlapping receptive fields, respectively). All the above mentioned machines heave binary weights. Our basic interest is focused on the storage capabilities of such networks which realize p= αN random, unbiased dichotomies (α denotes the so-called storage ratio). The analysis is done using the annealed approximation and is valid for all values of K. The critical (maximal) storage capacity of the fully connected Committee Machine reads α c =K, while in the case of the three-structure one gets α c =1, independent of K. The results obtained for the Parity Machine are exactly the same as those for the Committee network. The optimal storage of the AND Machine depends on distribution of the outputs for the patterns. These associations are studied in detail. We have found also that the capacity of the General Machines remains the same as compared to systems with fixed weights between intermediate layer and the output node. Some of the findings (especially those concerning the storage capacity of the Parity Machine) are in a good agreement with known numerical results. (author)

Methods for expanding the capacity of spent fuel storage facilities

International Nuclear Information System (INIS)

1990-06-01

At the beginning of 1989 more than 55,000 metric tonnes of heavy metal (MTHM) of spent Light Water Reactor (LWR) and Heavy Water Reactor (HWR) fuel had been discharged worldwide from nuclear power plants. Only a small fraction of this fuel has been reprocessed. The majority of the spent fuel assemblies are currently held at-reactor (AR) or away-from-reactor (AFR) in storage awaiting either chemical processing or final disposal depending on the fuel concept chosen by individual countries. Studies made by NEA and IAEA have projected that annual spent fuel arising will reach about 10,000 t HM in the year 2000 and cumulative arising will be more than 200,000 t HM. Taking into account the large quantity of spent fuel discharged from NPP and that the first demonstrations of the direct disposal of spent fuel or HLW are expected only after the year 2020, long-term storage will be the primary option for management of spent fuel until well into the next century. There are several options to expand storage capacity: (1) to construct new away-from-reactor storage facilities, (2) to transport spent fuel from a full at-reactor pool to another site for storage in a pool that has sufficient space to accommodate it, (3) to expand the capacity of existing AR pools by using compact racks, double-tierce, rod consolidation and by increasing the dimensions of existing pools. The purpose of the meeting was: to exchange new information on the international level on the subject connected with the expansion of storage capacities for spent fuel; to elaborate the state-of-the-art of this problem; to define the most important areas for future activity; on the basis of the above information to give recommendations to potential users for selection and application of the most suitable methods for expanding spent fuel facilities taking into account the relevant country's conditions. Refs, figs and tabs

Self-consistent signal-to-noise analysis of the statistical behavior of analog neural networks and enhancement of the storage capacity

Science.gov (United States)

Shiino, Masatoshi; Fukai, Tomoki

1993-08-01

Based on the self-consistent signal-to-noise analysis (SCSNA) capable of dealing with analog neural networks with a wide class of transfer functions, enhancement of the storage capacity of associative memory and the related statistical properties of neural networks are studied for random memory patterns. Two types of transfer functions with the threshold parameter θ are considered, which are derived from the sigmoidal one to represent the output of three-state neurons. Neural networks having a monotonically increasing transfer function FM, FM(u)=sgnu (||u||>θ), FM(u)=0 (||u||memory patterns), implying the reduction of the number of spurious states. The behavior of the storage capacity with changing θ is qualitatively the same as that of the Ising spin neural networks with varying temperature. On the other hand, the nonmonotonic transfer function FNM, FNM(u)=sgnu (||u||=θ) gives rise to remarkable features in several respects. First, it yields a large enhancement of the storage capacity compared with the Amit-Gutfreund-Sompolinsky (AGS) value: with decreasing θ from θ=∞, the storage capacity αc of such a network is increased from the AGS value (~=0.14) to attain its maximum value of ~=0.42 at θ~=0.7 and afterwards is decreased to vanish at θ=0. Whereas for θ>~1 the storage capacity αc coincides with the value αc~ determined by the SCSNA as the upper bound of α ensuring the existence of retrieval solutions, for θr≠0 (i.e., finite width of the local field distribution), which is implied by the order-parameter equations of the SCSNA, disappears at a certain critical loading rate α0, and for αr=0+). As a consequence, memory retrieval without errors becomes possible even in the saturation limit α≠0. Results of the computer simulations on the statistical properties of the novel phase with αstorage capacity is also analyzed for the two types of networks. It is conspicuous for the networks with FNM, where the self-couplings increase the stability of

Regeneration limit of classical Shannon capacity

Science.gov (United States)

Sorokina, M. A.; Turitsyn, S. K.

2014-05-01

Since Shannon derived the seminal formula for the capacity of the additive linear white Gaussian noise channel, it has commonly been interpreted as the ultimate limit of error-free information transmission rate. However, the capacity above the corresponding linear channel limit can be achieved when noise is suppressed using nonlinear elements; that is, the regenerative function not available in linear systems. Regeneration is a fundamental concept that extends from biology to optical communications. All-optical regeneration of coherent signal has attracted particular attention. Surprisingly, the quantitative impact of regeneration on the Shannon capacity has remained unstudied. Here we propose a new method of designing regenerative transmission systems with capacity that is higher than the corresponding linear channel, and illustrate it by proposing application of the Fourier transform for efficient regeneration of multilevel multidimensional signals. The regenerative Shannon limit—the upper bound of regeneration efficiency—is derived.

A new probability density function for spatial distribution of soil water storage capacity leads to SCS curve number method

OpenAIRE

Wang, Dingbao

2018-01-01

Following the Budyko framework, soil wetting ratio (the ratio between soil wetting and precipitation) as a function of soil storage index (the ratio between soil wetting capacity and precipitation) is derived from the SCS-CN method and the VIC type of model. For the SCS-CN method, soil wetting ratio approaches one when soil storage index approaches infinity, due to the limitation of the SCS-CN method in which the initial soil moisture condition is not explicitly represented. However, for the ...

Synthesis of NiPS3 and CoPS and its hydrogen storage capacity

International Nuclear Information System (INIS)

Ismail, N.; Madian, M.; El-Meligi, A.A.

2014-01-01

Highlights: • Preparation of NiPS 3 and CoPS using solid state reaction. • Characterization of compounds using XRD, TEM, SEM and IR. • Measuring the compounds thermal stability. • Estimation of the hydrogen storage capacity. -- Abstract: Prepared CoPS and NiPS 3 are studied as new materials for hydrogen energy storage. Single phase of CoPS and NiPS 3 were grown separately in evacuated silicatube via solid state reaction at 650 °C with controlled heating rate 1 °C/min. X-ray diffraction patterns confirm the formation of the desired compounds. Both CoPS and NiPS 3 exhibited high thermal stability up to 700 °C and 630 °C, respectively. The morphology of the prepared samples was investigated using scanning electron microscopy and folded sheets appeared in the transmission electron microscopy. The samples were exposed to 20 bar applied hydrogen pressure at 80 K. Both compounds appear to have feasible hydrogen storage capacity. CoPS was capable to adsorb 1.7 wt% while NiPS 3 storage capacity reached 1.2 wt%

Performance of phase change materials on storage capacity of trombe wall

International Nuclear Information System (INIS)

Al-Karaghouli, A.A.; Mujally, L.

2006-01-01

Two types of phase change materials were used as storage media in a Trombe Wall; namely paraffin wax (N-Eicoseue C 20 H 42 ) and Glaubers Salt (Na 2 SO 4 10H 2 O). To investigate the performance of these materials, a theoretical model and a simulation programme were developed. The wall temperature, the amount of heat stored, and the optimum wall thickness were calculated for both types. The study found that using two sheets of glass on the outside wall increased the surface wall temperature by around 50 degree C. It also found that Glauber salt was a much better storage material than paraffin wax. For a selected winter day at a location of 32 o N latitude, the storage capacity of the salt was more than twice that of the paraffin wax. The salt storage capacity was 32816 kJ/m 3 at an optimum wall thickness of 16 cm. this value for paraffin was 14464 kJ/m 3 at 13 cm optimum thickness. The study also concluded that according to this high heating value the wall uses, Glauber salt as a storage medium could supply its heat to the surrounding for a much longer period at night

Distributed coordination of energy-storage capacities in virtual microgrids

DEFF Research Database (Denmark)

Brehm, Robert; Ramezani, Hossein; Jouffroy, Jerome

cooperation is incorported, storage capacities can be operated as a virtual microgrid. The cooperation between nodes is based on the formulation of a simple objective function for coordination. The cooperation objective is then combined with each node’s local objective, which is the increase of self...

Superconducting magnetic energy storage, possibilities and limitations

International Nuclear Information System (INIS)

Bace, M.; Knapp, V.

1981-01-01

Energy storage is of great importance for the exploitation of new energy sources as well as for the better utilisation of conventional ones. Several proposals in recent years have suggested that superconducting magnets could be used as energy storage in large electricity networks. It is a purpose of this note to point out that the requirements which have to be met by energy storage in a large electricity network place serious limitation on the possible use of superconducting energy storage. (author)

CO2 sequestration: Storage capacity guideline needed

Science.gov (United States)

Frailey, S.M.; Finley, R.J.; Hickman, T.S.

2006-01-01

Petroleum reserves are classified for the assessment of available supplies by governmental agencies, management of business processes for achieving exploration and production efficiency, and documentation of the value of reserves and resources in financial statements. Up to the present however, the storage capacity determinations made by some organizations in the initial CO2 resource assessment are incorrect technically. New publications should thus cover differences in mineral adsorption of CO2 and dissolution of CO2 in various brine waters.

High Capacity Hydrogen Storage on Nanoporous Biocarbon

Science.gov (United States)

Burress, Jacob; Wood, Mikael; Gordon, Michael; Parilla, Phillip; Benham, Michael; Wexler, Carlos; Hawthorne, Fred; Pfeifer, Peter

2008-03-01

The Alliance for Collaborative Research in Alternative Fuel Technology (http://all-craft.missouri.edu) has been optimizing nanoporous biocarbon for high capacity hydrogen storage. The hydrogen storage was measured gravimetrically and volumetrically (Sievert's apparatus). These measurements have been validated by NREL and Hiden Isochema. Sample S-33/k, our current best performer, stores 73-91 g H2/kg carbon at 77 K and 47 bar, and 1.0-1.6 g H2/kg carbon at 293 K and 47 bar. Hydrogen isotherms run by Hiden Isochema have given experimental binding energies of 8.8 kJ/mol compared to the binding energy of graphite of 5 kJ/mol. Results from a novel boron doping technique will also be presented. The benefits and validity of using boron-doping on carbon will also be discussed.

Identification and capacity quantification of CO{sub 2} storage sites

Energy Technology Data Exchange (ETDEWEB)

Bachu, Stefan [Energy Resources Conservation Board (Canada)

2008-07-15

In this presentation the subject of scales of evaluation of the sites of CO{sub 2} storage is commented. Also the criteria to identify river basins and sites appropriated for the CO{sub 2} storage are analyzed and finally the matter of the estimation of the capacities of CO{sub 2} storage is analyzed. [Spanish] En esta presentacion se comenta sobre las escalas de evaluacion de los sitios de almacenamiento de CO{sub 2}. Tambien se analizan los criterios para identificar cuencas y lugares adecuados para el almacenamiento de CO{sub 2} y por ultimo se habla sobre la estimacion de las capacidades de almacenamiento de CO{sub 2}.

Energy density and storage capacity cost comparison of conceptual solid and liquid sorption seasonal heat storage systems for low-temperature space heating

NARCIS (Netherlands)

Scapino, L.; Zondag, H.A.; Van Bael, J.; Diriken, J.; Rindt, C.C.M.

Sorption heat storage can potentially store thermal energy for long time periods with a higher energy density compared to conventional storage technologies. A performance comparison in terms of energy density and storage capacity costs of different sorption system concepts used for seasonal heat

The effect of oxygen storage capacity on the dynamic characteristics of an automotive catalytic converter

International Nuclear Information System (INIS)

Shamim, Tariq

2008-01-01

Automotive catalytic converters, which are employed to reduce engine exhaust emissions, are subjected to highly transient conditions during a typical driving cycle. These transient conditions arise from changes in driving mode, the hysteresis and flow lags of the feedback control system, and result in fluctuations of air-fuel ratio, exhaust gas flow rates and temperatures. The catalyst performance is also strongly influenced by the oxygen storage capacity. This paper presents a computational investigation of the effect of oxygen storage capacity on the dynamic behavior of an automotive catalytic converter subjected to modulations in exhaust gases. The modulations are generated by forcing the temporal variations in exhaust gases air-fuel ratio, gas flow rates and temperatures. The study employs a single-channel based, one-dimensional, non-adiabatic model. The results show that the imposed modulations cause a significant departure in the catalyst behavior from its steady behavior, and the oxygen storage capacity plays an important role in determining the catalyst's response to the imposed modulations. Modulations and oxygen storage capacity are found to have relatively greater influence on the catalyst's performance near stoichiometric conditions

Assessment of Factors Influencing Effective CO₂ Storage Capacity and Injectivity in Eastern Gas Shales

Energy Technology Data Exchange (ETDEWEB)

Godec, Michael [Advanced Resources International, Inc., Arlington, VA (United States)

2013-06-30

Building upon advances in technology, production of natural gas from organic-rich shales is rapidly developing as a major hydrocarbon supply option in North America and around the world. The same technology advances that have facilitated this revolution - dense well spacing, horizontal drilling, and hydraulic fracturing - may help to facilitate enhanced gas recovery (EGR) and carbon dioxide (CO₂) storage in these formations. The potential storage of CO₂ in shales is attracting increasing interest, especially in Appalachian Basin states that have extensive shale deposits, but limited CO₂ storage capacity in conventional reservoirs. The goal of this cooperative research project was to build upon previous and on-going work to assess key factors that could influence effective EGR, CO₂ storage capacity, and injectivity in selected Eastern gas shales, including the Devonian Marcellus Shale, the Devonian Ohio Shale, the Ordovician Utica and Point Pleasant shale and equivalent formations, and the late Devonian-age Antrim Shale. The project had the following objectives: (1) Analyze and synthesize geologic information and reservoir data through collaboration with selected State geological surveys, universities, and oil and gas operators; (2) improve reservoir models to perform reservoir simulations to better understand the shale characteristics that impact EGR, storage capacity and CO₂ injectivity in the targeted shales; (3) Analyze results of a targeted, highly monitored, small-scale CO₂ injection test and incorporate into ongoing characterization and simulation work; (4) Test and model a smart particle early warning concept that can potentially be used to inject water with uniquely labeled particles before the start of CO₂ injection; (5) Identify and evaluate potential constraints to economic CO₂ storage in gas shales, and propose development approaches that overcome these constraints

Charge Modulation in Graphitic Carbon Nitride as a Switchable Approach to High-Capacity Hydrogen Storage.

Science.gov (United States)

Tan, Xin; Kou, Liangzhi; Tahini, Hassan A; Smith, Sean C

2015-11-01

Electrical charging of graphitic carbon nitride nanosheets (g-C4 N3 and g-C3 N4 ) is proposed as a strategy for high-capacity and electrocatalytically switchable hydrogen storage. Using first-principle calculations, we found that the adsorption energy of H2 molecules on graphitic carbon nitride nanosheets is dramatically enhanced by injecting extra electrons into the adsorbent. At full hydrogen coverage, the negatively charged graphitic carbon nitride achieves storage capacities up to 6-7 wt %. In contrast to other hydrogen storage approaches, the storage/release occurs spontaneously once extra electrons are introduced or removed, and these processes can be simply controlled by switching on/off the charging voltage. Therefore, this approach promises both facile reversibility and tunable kinetics without the need of specific catalysts. Importantly, g-C4 N3 has good electrical conductivity and high electron mobility, which can be a very good candidate for electron injection/release. These predictions may prove to be instrumental in searching for a new class of high-capacity hydrogen storage materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sc-Decorated Porous Graphene for High-Capacity Hydrogen Storage: First-Principles Calculations.

Science.gov (United States)

Chen, Yuhong; Wang, Jing; Yuan, Lihua; Zhang, Meiling; Zhang, Cairong

2017-08-02

The generalized gradient approximation (GGA) function based on density functional theory is adopted to investigate the optimized geometrical structure, electron structure and hydrogen storage performance of Sc modified porous graphene (PG). It is found that the carbon ring center is the most stable adsorbed position for a single Sc atom on PG, and the maximum number of adsorbed H₂ molecules is four with the average adsorption energy of -0.429 eV/H₂. By adding a second Sc atom on the other side of the system, the hydrogen storage capacity of the system can be improved effectively. Two Sc atoms located on opposite sides of the PG carbon ring center hole is the most suitable hydrogen storage structure, and the hydrogen storage capacity reach a maximum 9.09 wt % at the average adsorption energy of -0.296 eV/H₂. The adsorption of H₂ molecules in the PG system is mainly attributed to orbital hybridization among H, Sc, and C atoms, and Coulomb attraction between negatively charged H₂ molecules and positively charged Sc atoms.

Biphase Cobalt-Manganese Oxide with High Capacity and Rate Performance for Aqueous Sodium-Ion Electrochemical Energy Storage

Energy Technology Data Exchange (ETDEWEB)

Shan, Xiaoqiang [Univ. of New Hampshire, Durham, NH (United States). Dept. of Chemical Engineering; Charles, Daniel S. [Univ. of New Hampshire, Durham, NH (United States). Dept. of Chemical Engineering; Xu, Wenqian [Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS). X-ray Science Division; Feygenson, Mikhail [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical and Engineering Materials Division and Spallation Neutron Source (SNS) outstation Juelich Centre for Neutron Science (JCNS), Forschungszentrum Juelich GmbH; Su, Dong [Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN); Teng, Xiaowei [Univ. of New Hampshire, Durham, NH (United States). Dept. of Chemical Engineering

2017-11-22

Manganese-based metal oxide electrode materials are of great importance in electrochemical energy storage for their favorable redox behavior, low cost and environmental-friendliness. However, their storage capacity and cycle life in aqueous Na-ion electrolytes is not satisfactory. In this paper, we report the development of a bi-phase cobalt-manganese oxide (Co-Mn-O) nanostructured electrode material, comprised of a layered MnO₂.H₂O birnessite phase and a (Co_0.83Mn_0.13Va_0.04)tetra(Co_0.38Mn_1.62)_octaO_3.72 (Va: vacancy; tetra: tetrahedral sites; octa: octahedral sites) spinel phase, verified by neutron total scattering and pair distribution function analyses. The bi-phase Co-Mn-O material demonstrates an excellent storage capacity towards Na-ions in an aqueous electrolyte (121 mA h g^-1 at a scan rate of 1 mV s^-1 in the half-cell and 81 mA h g^-1 at a current density of 2 A g^-1 after 5000 cycles in full-cells), as well as high rate performance (57 mA h g^-1 a rate of 360 C). Electro-kinetic analysis and in situ X-ray diffraction measurements further confirm that the synergistic interaction between the spinel and layered phases, as well as the vacancy of the tetrahedral sites of spinel phase, contribute to the improved capacity and rate performance of the Co-Mn-O material by facilitating both diffusion-limited redox and capacitive charge storage processes.

Effects of Thinning Intensities on Soil Infiltration and Water Storage Capacity in a Chinese Pine-Oak Mixed Forest

OpenAIRE

Chen, Lili; Yuan, Zhiyou; Shao, Hongbo; Wang, Dexiang; Mu, Xingmin

2014-01-01

Thinning is a crucial practice in the forest ecosystem management. The soil infiltration rate and water storage capacity of pine-oak mixed forest under three different thinning intensity treatments (15%, 30%, and 60%) were studied in Qinling Mountains of China. The thinning operations had a significant influence on soil infiltration rate and water storage capacity. The soil infiltration rate and water storage capacity in different thinning treatments followed the order of control (nonthinning):

The effect of oxygen storage capacity on the dynamic characteristics of an automotive catalytic converter

Energy Technology Data Exchange (ETDEWEB)

Shamim, Tariq [Department of Mechanical Engineering, The University of Michigan-Dearborn, Dearborn, MI 48128-2406 (United States)

2008-11-15

Automotive catalytic converters, which are employed to reduce engine exhaust emissions, are subjected to highly transient conditions during a typical driving cycle. These transient conditions arise from changes in driving mode, the hysteresis and flow lags of the feedback control system, and result in fluctuations of air-fuel ratio, exhaust gas flow rates and temperatures. The catalyst performance is also strongly influenced by the oxygen storage capacity. This paper presents a computational investigation of the effect of oxygen storage capacity on the dynamic behavior of an automotive catalytic converter subjected to modulations in exhaust gases. The modulations are generated by forcing the temporal variations in exhaust gases air-fuel ratio, gas flow rates and temperatures. The study employs a single-channel based, one-dimensional, non-adiabatic model. The results show that the imposed modulations cause a significant departure in the catalyst behavior from its steady behavior, and the oxygen storage capacity plays an important role in determining the catalyst's response to the imposed modulations. Modulations and oxygen storage capacity are found to have relatively greater influence on the catalyst's performance near stoichiometric conditions. (author)

The capacity limitations of orientation summary statistics

Science.gov (United States)

Attarha, Mouna; Moore, Cathleen M.

2015-01-01

The simultaneous–sequential method was used to test the processing capacity of establishing mean orientation summaries. Four clusters of oriented Gabor patches were presented in the peripheral visual field. One of the clusters had a mean orientation that was tilted either left or right while the mean orientations of the other three clusters were roughly vertical. All four clusters were presented at the same time in the simultaneous condition whereas the clusters appeared in temporal subsets of two in the sequential condition. Performance was lower when the means of all four clusters had to be processed concurrently than when only two had to be processed in the same amount of time. The advantage for establishing fewer summaries at a given time indicates that the processing of mean orientation engages limited-capacity processes (Experiment 1). This limitation cannot be attributed to crowding, low target-distractor discriminability, or a limited-capacity comparison process (Experiments 2 and 3). In contrast to the limitations of establishing multiple summary representations, establishing a single summary representation unfolds without interference (Experiment 4). When interpreted in the context of recent work on the capacity of summary statistics, these findings encourage reevaluation of the view that early visual perception consists of summary statistic representations that unfold independently across multiple areas of the visual field. PMID:25810160

The Potential for Energy Storage to Provide Peaking Capacity in California Under Increased Penetration of Solar Photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Denholm, Paul L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-03-14

In this report, we examine the potential for replacing conventional peaking capacity in California with energy storage, including analysis of the changing technical potential with increased storage deployment and the effect of PV deployment. We examine nine years of historic load data, a range of storage durations (2-8 hours), and a range of PV penetration levels (0%-30%). We demonstrate how PV increases the ability of storage to reduce peak net demand. In the scenarios analyzed, the expected penetration of PV in California in 2020 could more than double the potential for 4-hour energy storage to provide capacity services.

Estimation of Potential Carbon Dioxide Storage Capacities of Onshore Sedimentary Basins in Republic of Korea

Science.gov (United States)

Park, S.; Kim, J.; Lee, Y.

2010-12-01

The potential carbon dioxide storage capacities of the five main onshore sedimentary basins (Chungnam, Gyeongsang, Honam, Mungyeong, and Taebaeksan Basins) in Republic of Korea are estimated based on the methods suggested by the United States National Energy Technology Laboratory (NETL). The target geologic formations considered for geologic storage of carbon dioxide in the sedimentary basins are sandstone and coal beds. The density of carbon dioxide is set equal to 446.4 kg/m3. The adsorption capacity and density of coal (anthracite) are set equal to 2.71 × 10-2 kg/kg and 1.82 × 103 kg/m3, respectively. The average storage efficiency factors for sandstone and coal are set equal to 2.5% and 34.0%, respectively. The Chungnam Basin has the sandstone volume of 72 km3 and the coal volume of 1.24 km3. The average porosity of sandstone in the Chungnam Basin is 3.8%. As a result, the potential carbon dioxide storage capacities of sandstone and coal in the Chungnam Basin are estimated to be 31 Mton and 21 Mton, respectively. The Gyeongsang Basin has the sandstone volume of 1,960 km3. The average porosity of sandstone in the Gyeongsang Basin is 4.6%. As a result, the potential carbon dioxide storage capacity of sandstone in the Gyeongsang Basin is estimated to be 1,011 Mton. The Honam Basin has the sandstone volume of 8 km3 and the coal volume of 0.27 km3. The average porosity of sandstone in the Honam Basin is 1.9%. As a result, the potential carbon dioxide storage capacities of sandstone and coal in the Honam Basin are estimated to be 2 Mton and 5 Mton, respectively. The Mungyeong Basin has the sandstone volume of 60 km3 and the coal volume of 0.66 km3. The average porosity of sandstone in the Mungyeong Basin is 2.0%. As a result, the potential carbon dioxide storage capacities of sandstone and coal in the Mungyeong Basin are estimated to be 13 Mton and 11 Mton, respectively. The Taebaeksan Basin has the sandstone volume of 71 km3 and the coal volume of 0.73 km3. The

Sc-Decorated Porous Graphene for High-Capacity Hydrogen Storage: First-Principles Calculations

Directory of Open Access Journals (Sweden)

Yuhong Chen

2017-08-01

Full Text Available The generalized gradient approximation (GGA function based on density functional theory is adopted to investigate the optimized geometrical structure, electron structure and hydrogen storage performance of Sc modified porous graphene (PG. It is found that the carbon ring center is the most stable adsorbed position for a single Sc atom on PG, and the maximum number of adsorbed H2 molecules is four with the average adsorption energy of −0.429 eV/H2. By adding a second Sc atom on the other side of the system, the hydrogen storage capacity of the system can be improved effectively. Two Sc atoms located on opposite sides of the PG carbon ring center hole is the most suitable hydrogen storage structure, and the hydrogen storage capacity reach a maximum 9.09 wt % at the average adsorption energy of −0.296 eV/H2. The adsorption of H2 molecules in the PG system is mainly attributed to orbital hybridization among H, Sc, and C atoms, and Coulomb attraction between negatively charged H2 molecules and positively charged Sc atoms.

Multi-Stage Transportation Problem With Capacity Limit

Directory of Open Access Journals (Sweden)

I. Brezina

2010-06-01

Full Text Available The classical transportation problem can be applied in a more general way in practice. Related problems as Multi-commodity transportation problem, Transportation problems with different kind of vehicles, Multi-stage transportation problems, Transportation problem with capacity limit is an extension of the classical transportation problem considering the additional special condition. For solving such problems many optimization techniques (dynamic programming, linear programming, special algorithms for transportation problem etc. and heuristics approaches (e.g. evolutionary techniques were developed. This article considers Multi-stage transportation problem with capacity limit that reflects limits of transported materials (commodity quantity. Discussed issues are: theoretical base, problem formulation as way as new proposed algorithm for that problem.

Increased Hydrologic Connectivity: Consequences of Reduced Water Storage Capacity in the Delmarva Peninsula (U.S.)

Science.gov (United States)

Mclaughlin, D. L.; Jones, C. N.; Evenson, G. R.; Golden, H. E.; Lane, C.; Alexander, L. C.; Lang, M.

2017-12-01

Combined geospatial and modeling approaches are required to fully enumerate wetland hydrologic connectivity and downstream effects. Here, we utilized both geospatial analysis and hydrologic modeling to explore drivers and consequences of modified surface water connectivity in the Delmarva Peninsula, with particular focus on increased connectivity via pervasive wetland ditching. Our geospatial analysis quantified both historical and contemporary wetland storage capacity across the region, and suggests that over 70% of historical storage capacity has been lost due to this ditching. Building upon this analysis, we applied a catchment-scale model to simulate implications of reduced storage capacity on catchment-scale hydrology. In short, increased connectivity (and concomitantly reduced wetland water storage capacity) decreases catchment inundation extent and spatial heterogeneity, shortens cumulative residence times, and increases downstream flow variation with evident effects on peak and baseflow dynamics. As such, alterations in connectivity have implications for hydrologically mediated functions in catchments (e.g., nutrient removal) and downstream systems (e.g., maintenance of flow for aquatic habitat). Our work elucidates such consequences in Delmarva Peninsula while also providing new tools for broad application to target wetland restoration and conservation. Views expressed are those of the authors and do not necessarily reflect policies of the US EPA or US FWS.

WORKING MEMORY CAPACITY TEST REVEALS SUBJECTS DIFFICULTIES MANAGING LIMITED CAPACITY

Directory of Open Access Journals (Sweden)

R V Ershova

2016-12-01

Full Text Available Free recall consists of two separate stages: the emptying of working memory and reactivation [5]. The Tarnow Unchunkable Test (TUT, [7] uses double integer items to separate out only the first stage by making it difficult to reactivate items due to the lack of intra-item relationships.193 Russian college students were tested via the internet version of the TUT. The average number of items remembered in the 3 item test was 2.54 items. In the 4 item test, the average number of items decreased to 2.38. This, and a number of other qualitative distribution differences between the 3 and 4 item tests, indicate that the average capacity limit of working memory has been reached at 3 items. This provides the first direct measurement of the unchunkable capacity limit of number items.Difficulties in managing working memory occurred as most subjects remembered less as the number of items increased beyond capacity and failed to remember a single item in at least one out of three 4 item trials. The Pearson correlation between the total recall of 3 and 4 items was a small 38%.

Simulation of Porous Medium Hydrogen Storage - Estimation of Storage Capacity and Deliverability for a North German anticlinal Structure

Science.gov (United States)

Wang, B.; Bauer, S.; Pfeiffer, W. T.

2015-12-01

Large scale energy storage will be required to mitigate offsets between electric energy demand and the fluctuating electric energy production from renewable sources like wind farms, if renewables dominate energy supply. Porous formations in the subsurface could provide the large storage capacities required if chemical energy carriers such as hydrogen gas produced during phases of energy surplus are stored. This work assesses the behavior of a porous media hydrogen storage operation through numerical scenario simulation of a synthetic, heterogeneous sandstone formation formed by an anticlinal structure. The structural model is parameterized using data available for the North German Basin as well as data given for formations with similar characteristics. Based on the geological setting at the storage site a total of 15 facies distributions is generated and the hydrological parameters are assigned accordingly. Hydraulic parameters are spatially distributed according to the facies present and include permeability, porosity relative permeability and capillary pressure. The storage is designed to supply energy in times of deficiency on the order of seven days, which represents the typical time span of weather conditions with no wind. It is found that using five injection/extraction wells 21.3 mio sm³ of hydrogen gas can be stored and retrieved to supply 62,688 MWh of energy within 7 days. This requires a ratio of working to cushion gas of 0.59. The retrievable energy within this time represents the demand of about 450000 people. Furthermore it is found that for longer storage times, larger gas volumes have to be used, for higher delivery rates additionally the number of wells has to be increased. The formation investigated here thus seems to offer sufficient capacity and deliverability to be used for a large scale hydrogen gas storage operation.

Final Project Report for DOE/EERE High-Capacity and Low-Cost Hydrogen-Storage Sorbents for Automotive Applications

Energy Technology Data Exchange (ETDEWEB)

Zhou, Hong-Cai [Texas A & M Univ., College Station, TX (United States); Liu, Di-Jia [Texas A & M Univ., College Station, TX (United States)

2017-12-01

This report provides a review of the objectives, progress, and milestones of the research conducted during this project on the topic of developing innovative metal-organic frameworks (MOFs) and porous organic polymers (POPs) for high-capacity and low-cost hydrogen-storage sorbents in automotive applications.1 The objectives of the proposed research were to develop new materials as next-generation hydrogen storage sorbents that meet or exceed DOE’s 2017 performance targets of gravimetric capacity of 0.055 kg H₂/kg_system and volumetric capacity of 0.040 kg H₂/L_system at a cost of $400/kg H_{2 stored}. Texas A&M University (TAMU) and Argonne National Laboratory (ANL) collaborated in developing low-cost and high-capacity hydrogen-storage sorbents with appropriate stability, sorption kinetics, and thermal conductivity. The research scope and methods developed to achieve the project’s goals include the following: Advanced ligand design and synthesis to construct MOF sorbents with optimal hydrogen storage capacities, low cost and high stability; Substantially improve the hydrogen uptake capacity and chemical stability of MOF-based sorbents by incorporating high valent metal ions during synthesis or through the post-synthetic metal metathesis oxidation approach; Enhance sorbent storage capacity through material engineering and characterization; Generate a better understanding of the H₂-sorbent interaction through advanced characterization and simulation. Over the course of the project 5 different MOFs were developed and studied: PCN-250, PCN-12, PCN-12’, PCN-608 and PCN-609.2-3 Two different samples were submitted to the National Renewable Energy Laboratory (NREL) in order to validate their hydrogen adsorption capacity, PCN-250 and PCN-12. Neither of these samples reached the project’s Go/No-Go requirements but the data obtained did further prove the hypothesis that the presence of open metal

High-capacity hydrogen storage in Li-adsorbed g-C{sub 3}N{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Wei, Jianfeng; Huang, Chengxi; Wu, Haiping, E-mail: mrhpwu@njust.edu.cn; Kan, Erjun, E-mail: ekan@njust.edu.cn

2016-09-01

Since hydrogen is a kind of potential source of efficient and pollution-free energy, it has attracted great research interests in recent years. However, the lack of safe and efficient hydrogen storage materials has blocked the rapid development of hydrogen energy. Here, we explored the possibility of Li-decorated g-C{sub 3}N{sub 4} as a kind of potential hydrogen storage materials based on first-principles calculations. Our results demonstrated that the adsorption energy of Li atoms on g-C{sub 3}N{sub 4} is much larger than the cohesive energy of bulk Li. Importantly, we find that the binding energy of each H{sub 2} molecule is about 0.29 eV, which is quite suitable for hydrogen storage. Furthermore, the estimated hydrogen storage capacity is around 9.2 wt %, which beyonds the goal of DOE. Thus, we predicted that Li-decorated g-C{sub 3}N{sub 4} may act as the potential hydrogen storage materials. - Highlights: • We explored the possibility of Li-decorated g-C{sub 3}N{sub 4} as a kind of potential hydrogen storage material. • We demonstrated the binding energy of each H{sub 2} molecule is 0.29 eV, which is quite suitable for hydrogen storage materials. • The hydrogen storage capacity is estimated around 9.2 wt %.

Limited capacity for contour curvature in iconic memory.

Science.gov (United States)

Sakai, Koji

2006-06-01

We measured the difference threshold for contour curvature in iconic memory by using the cued discrimination method. The study stimulus consisting of 2 to 6 curved contours was briefly presented in the fovea, followed by two lines as cues. Subjects discriminated the curvature of two cued curves. The cue delays were 0 msec. and 300 msec. in Exps. 1 and 2, respectively, and 50 msec. before the study offset in Exp. 3. Analysis of data from Exps. 1 and 2 showed that the Weber fraction rose monotonically with the increase in set size. Clear set-size effects indicate that iconic memory has a limited capacity. Moreover, clear set-size effect in Exp. 3 indicates that perception itself has a limited capacity. Larger set-size effects in Exp. 1 than in Exp. 3 suggest that iconic memory after perceptual process has limited capacity. These properties of iconic memory at threshold level are contradictory to the traditional view that iconic memory has a high capacity both at suprathreshold and categorical levels.

A Novel Method for Fast Configuration of Energy Storage Capacity in Stand-Alone and Grid-Connected Wind Energy Systems

Directory of Open Access Journals (Sweden)

Haixiang Zang

2016-12-01

Full Text Available In this paper, a novel method is proposed and applied to quickly calculate the capacity of energy storage for stand-alone and grid-connected wind energy systems, according to the discrete Fourier transform theory. Based on practical wind resource data and power data, which are derived from the American Wind Energy Technology Center and HOMER software separately, the energy storage capacity of a stand-alone wind energy system is investigated and calculated. Moreover, by applying the practical wind power data from a wind farm in Fujian Province, the energy storage capacity for a grid-connected wind system is discussed in this paper. This method can also be applied to determine the storage capacity of a stand-alone solar energy system with practical photovoltaic power data.

Activation of hydrogen storage materials in the Li-Mg-N-H system: Effect on storage properties

International Nuclear Information System (INIS)

Yang, Jun; Sudik, Andrea; Wolverton, C.

2007-01-01

We investigate the thermodynamics, kinetics, and capacity of the hydrogen storage reaction: Li 2 Mg(NH) 2 + 2H 2 ↔ Mg(NH 2 ) 2 + 2LiH. Starting with LiNH 2 and MgH 2 , two distinct procedures have been previously proposed for activating samples to induce the reversible storage reaction. We clarify here the impact of these two activation procedures on the resulting capacity for the Li-Mg-N-H reaction. Additionally, we measure the temperature-dependent kinetic absorption data for this hydrogen storage system. Finally, our experiments confirm the previously reported formation enthalpy (ΔH), hydrogen capacity, and pressure-composition-isotherm (PCI) data, and suggest that this system represents a kinetically (but not thermodynamically) limited system for vehicular on-board storage applications

Locational Prices in Capacity Subscription Market Considering Transmission Limitations

Directory of Open Access Journals (Sweden)

S. Babaeinejad Sarookolaee

2013-06-01

Full Text Available This study focuses on one of the most effective type of capacity markets named Capacity Subscription (CS market which is predicted to be widely used in the upcoming smart grids. Despite variant researches done about the mechanism and structure of capacity markets, their performances have been rarely tested in the presence of network constraints. Considering this deficiency, we tried to propose a new method to determine capacity prices in the network considering the transmission line flow limitations named Local capacity Prices (LP. This method is quite new and has not been tried before in any other similar researches. The philosophy of the proposed method is to determine capacity prices considering each consumer share of total peak demand. The first advantage of LP is that the consumers who benefit from the transmission facilities and are the responsible for transmission congestions, pay higher capacity prices than those whom their needed electricity is prepared locally. The second advantage of LP is that consumers connected to the same bus do not have to pay same capacity price due to their different shares of total peak demand. For more clarification, two other different methods named Branches Flow limit as a Global Limit (BFGL and Locational Capacity Prices (LCP are proposed and compared to the LP method in order to show LP method efficiency. The numerical results obtained from case studies show that the LP method follows more justice market procedure which results in more efficient capacity prices in comparison to BFGL and LCP methods.

Social exclusion weakens storage capacity and attentional filtering ability in visual working memory.

Science.gov (United States)

Xu, Mengsi; Qiao, Lei; Qi, Senqing; Li, Zhiai; Diao, Liuting; Fan, Lingxia; Zhang, Lijie; Yang, Dong

2018-01-01

Social exclusion has been found to impair visual working memory (WM), while the underlying neural processes are currently unclear. Using two experiments, we tested whether the poor WM performance caused by exclusion was due to reduced storage capacity, impaired attentional filtering ability or both. The Cyberball game was used to manipulate social exclusion. Seventy-four female participants performed WM tasks while event-related potentials were recorded. In Experiment 1, participants were made to remember the orientations of red rectangles while ignoring salient green rectangles. Results showed that exclusion impaired the ability to filter out irrelevant items from WM, as reflected by the similar contralateral delay activity (CDA) amplitudes for one-target-one-distractor condition and two-targets condition, as well as the similar CDA amplitudes for two-targets-two-distractors condition and four-targets condition in excluded individuals. In Experiment 2, participants were asked to remember 1-5 colored squares. Results showed that exclusion reduced storage capacity, as the CDA amplitudes reached asymptote at loads of two items for exclusion group and at loads of three items for inclusion group. Together, these two experiments provided complementary evidence that WM deficits caused by social exclusion were due to reduced storage capacity and impaired attentional filtering ability. © The Author (2017). Published by Oxford University Press.

Delay-Limited Capacity in the Low Power Regime

KAUST Repository

Rezki, Zouheir

2016-02-11

Outage performance of the M-block fading with additive white Gaussian noise (BF-AWGN) is investigated in the low-power regime. We consider delay-constrained constant-rate communications with perfect channel state information (CSI) at both the transmitter and the receiver (CSI-TR), under a shortterm power constraint (STPC) and a long-term power constraint (LTPC). Subject to STPC, we show that selection diversity that allocates all the power to the strongest block is asymptotically optimal. Then, we provide a simple characterization of the outage probability in the regime of interest. We quantify the reward due to CSI-TR over the constant-rate constant-power scheme and show that this reward increases with the delay constraint. For instance, for Rayleigh fading, we find that a power gain up to 4.3 dB is achievable. Subject to LTPC, we show that the above guidelines still holds and that the outage performance improves due to the flexibility of the LTPC over the STPC. More interestingly, we prove that LTPC allows zero-outage communication even at low SNR and characterize the delaylimited capacity at low SNR in a simple form. More precisely, we establish that the delay-limited capacity scales linearly with the power constraint, for a given M < 1. Our framework highlights the benefit of fading at low SNR as the delay-limited capacity may outperform the AWGN capacity. For instance, for Rayleigh fading and with M = 3, the delay-limited capacity is 16% higher than the capacity of an AWGN channel.

Development of high-capacity antimatter storage

International Nuclear Information System (INIS)

Howe, Steven D.; Smith, Gerald A.

2000-01-01

Space is vast. Over the next few decades, humanity will strive to send probes farther and farther into space to establish long baselines for interferometry, to visit the Kuiper Belt, to identify the heliopause, or to map the Oort cloud. In order to solve many of the mysteries of the universe or to explore the solar system and beyond, one single technology must be developed--high performance propulsion. In essence, future missions to deep space will require specific impulses between 50,000 and 200,000 seconds and energy densities greater than 10 14 j/kg in order to accomplish the mission within the career lifetime of an individual, 40 years. Only two technologies available to mankind offer such performance--fusion and antimatter. Currently envisioned fusion systems are too massive. Alternatively, because of the high energy density, antimatter powered systems may be relatively compact. The single key technology that is required to enable the revolutionary concept of antimatter propulsion is safe, reliable, high-density storage. Under a grant from the NASA Institute of Advanced Concepts, we have identified two potential mechanisms that may enable high capacity antimatter storage systems to be built. We will describe planned experiments to verify the concepts. Development of a system capable of storing megajoules per gram will allow highly instrumented platforms to make fast missions to great distances. Such a development will open the universe to humanity

Short-term storage capacity for visual objects depends on expertise

DEFF Research Database (Denmark)

Sørensen, Thomas Alrik; Kyllingsbæk, Søren

2012-01-01

Visual short-term memory (VSTM) has traditionally been thought to have a very limited capacity of around 3–4 objects. However, recently several researchers have argued that VSTM may be limited in the amount of information retained rather than by a specific number of objects. Here we present a study...... of the effect of long-term practice on VSTM capacity. We investigated four age groups ranging from pre-school children to adults and measured the change in VSTM capacity for letters and pictures. We found a clear increase in VSTM capacity for letters with age but not for pictures. Our results indicate that VSTM...

A solar receiver-storage modular cascade based on porous ceramic structures for hybrid sensible/thermochemical solar energy storage

OpenAIRE

Agrafiotis, Christos; de Oliveira, Lamark; Roeb, Martin; Sattler, Christian

2016-01-01

The current state-of-the-art solar heat storage concept in air-operated Solar Tower Power Plants is to store the solar energy provided during on-sun operation as sensible heat in porous solid materials that operate as recuperators during off-sun operation. The technology is operationally simple; however its storage capacity is limited to 1.5 hours. An idea for extending this capacity is to render this storage concept from “purely” sensible to “hybrid” sensible/ thermochemical one, via coating...

Dynamics of social contagions with limited contact capacity.

Science.gov (United States)

Wang, Wei; Shu, Panpan; Zhu, Yu-Xiao; Tang, Ming; Zhang, Yi-Cheng

2015-10-01

Individuals are always limited by some inelastic resources, such as time and energy, which restrict them to dedicate to social interaction and limit their contact capacities. Contact capacity plays an important role in dynamics of social contagions, which so far has eluded theoretical analysis. In this paper, we first propose a non-Markovian model to understand the effects of contact capacity on social contagions, in which each adopted individual can only contact and transmit the information to a finite number of neighbors. We then develop a heterogeneous edge-based compartmental theory for this model, and a remarkable agreement with simulations is obtained. Through theory and simulations, we find that enlarging the contact capacity makes the network more fragile to behavior spreading. Interestingly, we find that both the continuous and discontinuous dependence of the final adoption size on the information transmission probability can arise. There is a crossover phenomenon between the two types of dependence. More specifically, the crossover phenomenon can be induced by enlarging the contact capacity only when the degree exponent is above a critical degree exponent, while the final behavior adoption size always grows continuously for any contact capacity when degree exponent is below the critical degree exponent.

Shared filtering processes link attentional and visual short-term memory capacity limits.

Science.gov (United States)

Bettencourt, Katherine C; Michalka, Samantha W; Somers, David C

2011-09-30

Both visual attention and visual short-term memory (VSTM) have been shown to have capacity limits of 4 ± 1 objects, driving the hypothesis that they share a visual processing buffer. However, these capacity limitations also show strong individual differences, making the degree to which these capacities are related unclear. Moreover, other research has suggested a distinction between attention and VSTM buffers. To explore the degree to which capacity limitations reflect the use of a shared visual processing buffer, we compared individual subject's capacities on attentional and VSTM tasks completed in the same testing session. We used a multiple object tracking (MOT) and a VSTM change detection task, with varying levels of distractors, to measure capacity. Significant correlations in capacity were not observed between the MOT and VSTM tasks when distractor filtering demands differed between the tasks. Instead, significant correlations were seen when the tasks shared spatial filtering demands. Moreover, these filtering demands impacted capacity similarly in both attention and VSTM tasks. These observations fail to support the view that visual attention and VSTM capacity limits result from a shared buffer but instead highlight the role of the resource demands of underlying processes in limiting capacity.

Evaluating the Cost of Line Capacity Limitations in Aggregations of Commercial Buildings

DEFF Research Database (Denmark)

Ziras, Charalampos; Delikaraoglou, Stefanos; Kazempour, Jalal

2017-01-01

-ahead optimization strategy to assess the cost of imposing capacity limitations in the total consumption of individual buildings, as well as aggregations of buildings. We show that such capacity limitations lead to an increase for the buildings operational costs, which can be interpreted as the value...... of these limitations. Based on such calculations, the aggregator can value capacity-limitation services to the distribution system operator. Moreover, the value of aggregation is also highlighted, since it leads to lower costs than imposing the same total capacity limitation on individual buildings....

Oxygen- and capacity-limited thermal tolerance

DEFF Research Database (Denmark)

Jutfelt, Fredrik; Norin, Tommy; Ern, Rasmus

2018-01-01

The Commentary by Pörtner, Bock and Mark (Pörtner et al., 2017) elaborates on the oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis. Journal of Experimental Biology Commentaries allow for personal and controversial views, yet the journal also mandates that ‘opinion and fact must b...

Review of private sector treatment, storage, and disposal capacity for radioactive waste. Revision 1

International Nuclear Information System (INIS)

Smith, M.; Harris, J.G.; Moore-Mayne, S.; Mayes, R.; Naretto, C.

1995-01-01

This report is an update of a report that summarized the current and near-term commercial and disposal of radioactive and mixed waste. This report was capacity for the treatment, storage, dating and written for the Idaho National Engineering Laboratory (INEL) with the objective of updating and expanding the report entitled ''Review of Private Sector Treatment, Storage, and Disposal Capacity for Radioactive Waste'', (INEL-95/0020, January 1995). The capacity to process radioactively-contaminated protective clothing and/or respirators was added to the list of private sector capabilities to be assessed. Of the 20 companies surveyed in the previous report, 14 responded to the request for additional information, five did not respond, and one asked to be deleted from the survey. One additional company was identified as being capable of performing LLMW treatability studies and six were identified as providers of laundering services for radioactively-contaminated protective clothing and/or respirators

Review of private sector treatment, storage, and disposal capacity for radioactive waste. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Smith, M.; Harris, J.G.; Moore-Mayne, S.; Mayes, R.; Naretto, C.

1995-04-14

This report is an update of a report that summarized the current and near-term commercial and disposal of radioactive and mixed waste. This report was capacity for the treatment, storage, dating and written for the Idaho National Engineering Laboratory (INEL) with the objective of updating and expanding the report entitled ``Review of Private Sector Treatment, Storage, and Disposal Capacity for Radioactive Waste``, (INEL-95/0020, January 1995). The capacity to process radioactively-contaminated protective clothing and/or respirators was added to the list of private sector capabilities to be assessed. Of the 20 companies surveyed in the previous report, 14 responded to the request for additional information, five did not respond, and one asked to be deleted from the survey. One additional company was identified as being capable of performing LLMW treatability studies and six were identified as providers of laundering services for radioactively-contaminated protective clothing and/or respirators.

Modelling transport-limited discharge capacity of lithium-sulfur cells

International Nuclear Information System (INIS)

Zhang, Teng; Marinescu, Monica; Walus, Sylwia; Offer, Gregory J.

2016-01-01

Highlights: • We modelled the rate capability of a Li-S cell based on mass-transport limitation • The model predicts a discharged Li-S cell to regain capacity upon short relaxation • Modelled rate capability and capacity recovery effect validated with measurements - Abstract: Lithium-sulfur (Li-S) battery could bring a step-change in battery technology with a potential specific energy density of 500 - 600 Wh/kg. A key challenge for further improving the specific energy-density of Li-S cells is to understand the mechanisms behind reduced sulfur utilisation at low electrolyte loadings and high discharge currents. While several Li-S models have been developed to explore the discharge mechanisms of Li-S cells, they so far fail to capture the discharge profiles at high currents. In this study, we propose that the slow ionic transport in concentrated electrolyte is limiting the rate capability of Li-S cells. This transport-limitation mechanism is demonstrated through a one-dimensional Li-S model which qualitatively captures the discharge capacities of a sulfolane-based Li-S cell at different currents. Furthermore, our model predicts that a discharged Li-S cell is able regain some capacity with a short period of relaxation. This capacity recovery phenomenon is validated experimentally for different discharge currents and relaxation durations. The transport-limited discharge behavior of Li-S cells highlights the importance of optimizing the electrolyte loading and electrolyte transport property in Li-S cells.

Effects of reducing temperatures on the hydrogen storage capacity of double-walled carbon nanotubes with Pd loading.

Science.gov (United States)

Sheng, Qu; Wu, Huimin; Wexler, David; Liu, Huakun

2014-06-01

The effects of different temperatures on the hydrogen sorption characteristics of double-walled carbon nanotubes (DWCNTs) with palladium loading have been investigated. When we use different temperatures, the particle sizes and specific surface areas of the samples are different, which affects the hydrogen storage capacity of the DWCNTs. In this work, the amount of hydrogen storage capacity was determined (by AMC Gas Reactor Controller) to be 1.70, 1.85, 2.00, and 1.93 wt% for pristine DWCNTS and for 2%Pd/DWCNTs-300 degrees C, 2%Pd/DWCNTs-400 degrees C, and 2%Pd/DWCNTs-500 degrees C, respectively. We found that the hydrogen storage capacity can be enhanced by loading with 2% Pd nanoparticles and selecting a suitable temperature. Furthermore, the sorption can be attributed to the chemical reaction between atomic hydrogen and the dangling bonds of the DWCNTs.

Remote Sensing Insights into Storage Capacities among Plains Village Horticulturalists

Science.gov (United States)

Wiewel, Adam S.

Maize was a fundamental component of the diet and economy of Middle Missouri Plains Village groups, sedentary farmers with settlements along the Missouri River during the last millennia. More than a century of study has contributed to our understanding of agricultural production among these peoples, but little effort has been made to consider temporal variation in production. Such an understanding is crucial to examining changes that occurred before and after the arrival of colonists and their trade goods in the seventeenth century. Plains archaeologists have suggested that the storage capacity of Middle Missouri villages increased during the sixteenth through the eighteenth centuries. In fact, the number and size of subterranean storage pits, ubiquitous features within most settlements, are thought to have grown during these centuries, which reflects greater agricultural production. To further examine changes in production and storage capacity during this centuries-long period, I combine information from historical documents, excavations, and geophysical investigations. At Huff Village, a fifteenth-century community, excavations and magnetic gradiometry surveys reveal the size and distribution of storage pits. Their number and average volume suggest the villagers grew immense amounts of food and contributed to widespread intertribal trade. Furthermore, storage pit excavation data from 20 regional sites, dating from the thirteenth to the nineteenth century, indicate pit volumes increased through the seventeenth century. A sharp decrease subsequently occurred during the eighteenth century due to epidemic disease. However, mean pit volumes were significantly larger during the nineteenth century, evidence of the resilience of Mandans, Hidatsas, and Arikaras and the continued significance of maize. In fact, historical documents and remote sensing data suggest the Mandans and Arikaras, successive occupants of an earthlodge village near the American Fur Company's Fort

Capacity enhancement of aqueous borohydride fuels for hydrogen storage in liquids

International Nuclear Information System (INIS)

Schubert, David; Neiner, Doinita; Bowden, Mark; Whittemore, Sean; Holladay, Jamie; Huang, Zhenguo; Autrey, Tom

2015-01-01

Highlights: • Adjusting ratio of Q = Na/B will maximize H 2 storage capacity of liquid carrier. • Mixtures of hydrolysis products are desirable to maximize solubility. • 6.5 wt.% hydrogen and remains liquid from beginning to end. - Abstract: In this work we demonstrate enhanced hydrogen storage capacities through increased solubility of sodium borate product species in aqueous media achieved by adjusting the sodium (NaOH) to boron (B(OH) 3 ) ratio, i.e., M/B, to obtain a distribution of polyborate anions. For a 1:1 mol ratio of NaOH to B(OH) 3 , M/B = 1, the ratio of the hydrolysis product formed from NaBH 4 hydrolysis, the sole borate species formed and observed by 11 B NMR is sodium metaborate, NaB(OH) 4 . When the ratio is 1:3 NaOH to B(OH) 3 , M/B = 0.33, a mixture of borate anions is formed and observed as a broad peak in the 11 B NMR spectrum. The complex polyborate mixture yields a metastable solution that is difficult to crystallize. Given the enhanced solubility of the polyborate mixture formed when M/B = 0.33 it should follow that the hydrolysis of sodium octahydrotriborate, NaB 3 H 8 , can provide a greater storage capacity of hydrogen for fuel cell applications compared to sodium borohydride while maintaining a single phase. Accordingly, the hydrolysis of a 23 wt.% NaB 3 H 8 solution in water yields a solution having the same complex polyborate mixture as formed by mixing a 1:3 M ratio of NaOH and B(OH) 3 and releases >8 eq of H 2 . By optimizing the M/B ratio a complex mixture of soluble products, including B 3 O 3 (OH) 5 2− , B 4 O 5 (OH) 4 2− , B 3 O 3 (OH) 4 − , B 5 O 6 (OH) 4 − and B(OH) 3 , can be maintained as a single liquid phase throughout the hydrogen release process. Consequently, hydrolysis of NaB 3 H 8 can provide a 40% increase in H 2 storage density compared to the hydrolysis of NaBH 4 given the decreased solubility of sodium metaborate

Conductive Boron-Doped Graphene as an Ideal Material for Electrocatalytically Switchable and High-Capacity Hydrogen Storage.

Science.gov (United States)

Tan, Xin; Tahini, Hassan A; Smith, Sean C

2016-12-07

Electrocatalytic, switchable hydrogen storage promises both tunable kinetics and facile reversibility without the need for specific catalysts. The feasibility of this approach relies on having materials that are easy to synthesize, possessing good electrical conductivities. Graphitic carbon nitride (g-C 4 N 3 ) has been predicted to display charge-responsive binding with molecular hydrogen-the only such conductive sorbent material that has been discovered to date. As yet, however, this conductive variant of graphitic carbon nitride is not readily synthesized by scalable methods. Here, we examine the possibility of conductive and easily synthesized boron-doped graphene nanosheets (B-doped graphene) as sorbent materials for practical applications of electrocatalytically switchable hydrogen storage. Using first-principle calculations, we find that the adsorption energy of H 2 molecules on B-doped graphene can be dramatically enhanced by removing electrons from and thereby positively charging the adsorbent. Thus, by controlling charge injected or depleted from the adsorbent, one can effectively tune the storage/release processes which occur spontaneously without any energy barriers. At full hydrogen coverage, the positively charged BC 5 achieves high storage capacities up to 5.3 wt %. Importantly, B-doped graphene, such as BC 49 , BC 7 , and BC 5 , have good electrical conductivity and can be easily synthesized by scalable methods, which positions this class of material as a very good candidate for charge injection/release. These predictions pave the route for practical implementation of electrocatalytic systems with switchable storage/release capacities that offer high capacity for hydrogen storage.

Theoretical storage capacity for solar air pretreatment liquid collector/regenerator

Energy Technology Data Exchange (ETDEWEB)

Peng, Donggen; Zhang, Xiaosong; Yin, Yonggao [School of Energy and Environment, Southeast University, Nanjing 210096 (China)

2008-08-15

A new liquid regeneration equipment - solar air pretreatment collector/regenerator for liquid desiccant cooling system is put forward in this paper, which is preferable to solution regeneration in hot and moist climate in South China. The equipment can achieve liquid regeneration in lower temperature. When the solution and the air are in ''match'' state in collector/regenerator, a match air to salt mass ratio ASMR* is found by theoretical study in which there is the largest theoretical storage capacity SC{sub max}. At T{sub r} = 60{sup o}C and X{sub in} 2.33 kg/kg, theoretical calculation discovers when Y{sub in} drops from 29 to 14 g/kg, the SC{sub max} increase 50% compared with ASMR{sup *} being around 26-27. After two new concepts of the effective solution proportion (EPS) and the effective storage capacity (ESC) are defined, it is found by theoretical calculation that when ESP drops from 100% to 67%, ESC raises lowly, not drops and liquid outlet concentration C{sub str.sol} increases from 40% to 49% in which its increment totals to 90%. All these data explain fully that air pretreatment liquid regeneration equipment enables to improve the performance of liquid desiccant cooling system. (author)

External electric field: An effective way to prevent aggregation of Mg atoms on γ-graphyne for high hydrogen storage capacity

International Nuclear Information System (INIS)

Liu, Ping-Ping; Zhang, Hong; Cheng, Xin-Lu; Tang, Yong-Jian

2016-01-01

Highlights: • Due to large pores in the sheet of γ-graphyne, it should be a potential materials for energy storage applications. Our calculations might motivate active experimental efforts in designing high-efficiency hydrogen storage media. • For the first time, we use an applied external electric field to prevent Mg atoms from clustering using density functional theory (DFT) calculations. • The results demonstrate that, for Mg-G after electric field (F = 0.05 V/nm) treatment, ten H_2 molecules per Mg atom can be adsorbed and the hydrogen storage capacities reach to 10.64 wt%, with the average binding energies of 0.28 eV/H_2. - Abstract: In this article, we investigate the hydrogen storage capacity of Mg-decorated γ-graphyne (Mg-G) based on DFT calculations. Our results indicate that an external electric field can effectively prevent Mg atoms aggregating on γ-graphyne sheet. The Mg-G, after electric field (F = 0.05 V/nm) treatment, can store up to ten H_2 molecules and the hydrogen storage capacity is 10.64 wt%, with the average adsorption energy of 0.28 eV/H_2. Our calculations demonstrate that Mg-G is a potential material for hydrogen storage with high capacity and might motivate active experimental efforts in designing hydrogen storage media.

Antioxidant capacity of fresh and stored breast milk: is -80°C optimal temperature for freeze storage?

Science.gov (United States)

Sari, Fatma Nur; Akdag, Arzu; Dizdar, Evrim Alyamac; Uras, Nurdan; Erdeve, Omer; Erel, Ozcan; Dilmen, Ugur

2012-06-01

To determine total antioxidant capacity and total oxidation status in fresh and freeze stored (at -80°C) breast milk during the stages of lactation. Samples of colostrum, transitional and mature milk were collected from 44 healthy women at 3, 8 and 30 days after birth. The total milk volume collected (6 ml) was divided in two aliquot parts: 3 ml for the fresh analysis which was done immediately after the extraction and 3 ml for storage under freezing conditions at -80°C for two months. The antioxidant status and oxidative stress of the fresh and stored breast milk were assessed via determination of total antioxidant capacity and total oxidation status. Antioxidant capacity of transitional and mature milk decreased (p = 0.0001, p = 0.028, respectively); however, antioxidant capacity of colostrum did not change by storage at -80°C (p > 0.05). Total antioxidant capacity of fresh and stored breast milk significantly decreased during the stages of lactation (p Total oxidation status showed no significant difference in fresh and stored breast milk during the stages of lactation (p > 0.05). Freeze storage of breast milk at -80°C for two months seems not to be the optimal condition to preserve the antioxidant capacity of breast milk.

The Nature of the Capacity Limitations in Visual Short-Term Memory

DEFF Research Database (Denmark)

Sørensen, Thomas Alrik; Kyllingsbæk, Søren

Several studies have explored the nature and in particular the limitations of human visual short-term memory (VSTM) (e.g. Luck & Vogel, 1997). A VSTM capacity limit of about 3 to 4 objects has been found, thus confirming results from earlier studies (e.g. Sperling, 1960). However, Alvarez...... either Arabic or Japanese. Our results indicate that VSTM capacity for familiar items - compared to unfamiliar - is larger, irrespective of their visual complexity, hereby suggesting that visual long-term memory representation and training play an important role in regard to the capacity limitations...

Climate controls how ecosystems size the root zone storage capacity at catchment scale

NARCIS (Netherlands)

Gao, H.; Hrachowitz, M.; Schymanski, S.J.; Fenicia, F.F.; Sriwongsitanon, N.; Savenije, H.H.G.

2014-01-01

The root zone moisture storage capacity (SR) of terrestrial ecosystems is a buffer providing vegetation continuous access to water and a critical factor controlling land-atmospheric moisture exchange, hydrological response, and biogeochemical processes. However, it is impossible to observe directly

Hydrological properties of bark of selected forest tree species. Part 2: Interspecific variability of bark water storage capacity

Directory of Open Access Journals (Sweden)

Ilek Anna

2017-06-01

Full Text Available The subject of the present research is the water storage capacity of bark of seven forest tree species: Pinus sylvestris L., Larix decidua Mill., Abies alba Mill., Pinus sylvestris L., Quercus robur L., Betula pendula Ehrh. and Fagus sylvatica L. The aim of the research is to demonstrate differences in the formation of bark water storage capacity between species and to identify factors influencing the hydrological properties of bark. The maximum water storage capacity of bark was determined under laboratory conditions by performing a series of experiments simulating rainfall and by immersing bark samples in containers filled with water. After each single experiment, the bark samples were subjected to gravity filtration in a desiccator partially filled with water. The experiments lasted from 1084 to 1389 hours, depending on the bark sample. In all the studied species, bark sampled from the thinnest trees is characterized by the highest water storage capacity expressed in mm H2O · cm-3, while bark sampled from the thickest trees - by the lowest capacity. On the other hand, bark sampled from the thickest trees is characterized by the highest water storage capacity expressed in H2O · cm-2 whereas bark from the thinnest trees - by the lowest capacity. In most species tested, as the tree thickness and thus the bark thickness and the coefficient of development of the interception surface of bark increase, the sorption properties of the bark decrease with bark depth, and the main role in water retention is played by the outer bark surface. The bark of European beech is an exception because of the smallest degree of surface development and because the dominant process is the absorption of water. When examining the hydrological properties of bark and calculating its parameters, one needs to take into account the actual surface of the bark of trees. Disregarding the actual bark surface may lead to significant errors in the interpretation of research

Bathymetry and Sediment-Storage Capacity Change in Three Reservoirs on the Lower Susquehanna River, 1996-2008

Science.gov (United States)

Langland, Michael J.

2009-01-01

The Susquehanna River transports a substantial amount of the sediment and nutrient load to the Chesapeake Bay. Upstream of the bay, three large dams and their associated reservoirs trap a large amount of the transported sediment and associated nutrients. During the fall of 2008, the U.S. Geological Survey in cooperation with the Pennsylvania Department of Environmental Protection completed bathymetric surveys of three reservoirs on the lower Susquehanna River to provide an estimate of the remaining sediment-storage capacity. Previous studies indicated the upper two reservoirs were in equilibrium with long-term sediment storage; only the most downstream reservoir retained capacity to trap sediments. A differential global positioning system (DGPS) instrument was used to provide the corresponding coordinate position. Bathymetry data were collected using a single beam 210 kHz (kilohertz) echo sounder at pre-defined transects that matched previous surveys. Final horizontal (X and Y) and vertical (Z) coordinates of the geographic positions and depth to bottom were used to create bathymetric maps of the reservoirs. Results indicated that from 1996 to 2008 about 14,700,000 tons of sediment were deposited in the three reservoirs with the majority (12,000,000 tons) being deposited in Conowingo Reservoir. Approximately 20,000 acre-feet or 30,000,000 tons of remaining storage capacity is available in Conowingo Reservoir. At current transport (3,000,000 tons per year) and deposition (2,000,000 tons per year) rates and with no occurrence of major scour events due to floods, the remaining capacity may be filled in 15 to 20 years. Once the remaining sediment-storage capacity in the reservoirs is filled, sediment and associated phosphorus loads entering the Chesapeake Bay are expected to increase.

Dietary Probiotic Bacillus subtilis Strain fmbj Increases Antioxidant Capacity and Oxidative Stability of Chicken Breast Meat during Storage

Science.gov (United States)

Bai, Wen Kai; Zhang, Fei Jing; He, Tian Jin; Su, Peng Wei; Ying, Xiong Zhi; Zhang, Li Li; Wang, Tian

2016-01-01

This study was aimed to measure the dietary effects of probiotic Bacillus subtilis strain fmbj (BS fmbj) on antioxidant capacity and oxidative stability of chicken breast meat during storage. Treatment groups were fed the basal diet with BS fmbj at 0 g/kg (CON), 0.2 g/kg (BS-1), 0.3 g/kg (BS-2), or 0.4 g/kg (BS-3) doses without antibiotics. During 8 days of storage at 4°C, BS-2 group showed a significant improvement (P Cooking loss, Shear force, color L*, a*, b*), free radical scavenging activity (DPPH, ABTS+, H2O2), tissues antioxidant enzyme capacity (SOD, CAT, GSH-Px, GSH, T-SH), mitochondria antioxidant enzyme capacity (MnSOD, GPx, GSH), mRNA expression of antioxidant genes (Nrf2, HO-1, SOD, CAT, GSH-Px) and mitochondrial function genes (avUCP, NRF1, NRF2, TFAM, PGC-1α), oxidative damage index (MDA, ROS, PC, 8-OHdG), and MMP level in chicken breast meat as compared to the CON group. These results indicate that dietary BS fmbj in broiler diets can protect breast meat against the storage-induced oxidative stress by improving their free radical scavenging capacity and antioxidant activity during 8 days of storage at 4°C. PMID:27907152

The Baltic Basin: structure, properties of reservoir rocks, and capacity for geological storage of CO2

Directory of Open Access Journals (Sweden)

Vaher, Rein

2009-12-01

Full Text Available Baltic countries are located in the limits of the Baltic sedimentary basin, a 700 km long and 500 km wide synclinal structure. The axis of the syneclise plunges to the southwest. In Poland the Precambrian basement occurs at a depth of 5 km. The Baltic Basin includes the Neoproterozoic Ediacaran (Vendian at the base and all Phanerozoic systems. Two aquifers, the lower Devonian and Cambrian reservoirs, meet the basic requirements for CO2 storage. The porosity and permeability of sandstone decrease with depth. The average porosity of Cambrian sandstone at depths of 80–800, 800–1800, and 1800–2300 m is 18.6, 14.2, and 5.5%, respectively. The average permeability is, respectively, 311, 251, and 12 mD. Devonian sandstone has an average porosity of 26% and permeability in the range of 0.5–2 D. Prospective Cambrian structural traps occur only in Latvia. The 16 largest ones have CO2 storage capacity in the range of 2–74 Mt, with total capacity exceeding 400 Mt. The structural trapping is not an option for Lithuania as the uplifts there are too small. Another option is utilization of CO2 for enhanced oil recovery (EOR. The estimated total EOR net volume of CO2 (part of CO2 remaining in the formation in Lithuania is 5.6 Mt. Solubility and mineral trapping are a long-term option. The calculated total solubility trapping capacity of the Cambrian reservoir is as high as 11 Gt of CO2 within the area of the supercritical state of carbon dioxide.

Optimizing Capacities of Distributed Generation and Energy Storage in a Small Autonomous Power System Considering Uncertainty in Renewables

Directory of Open Access Journals (Sweden)

Ying-Yi Hong

2015-03-01

Full Text Available This paper explores real power generation planning, considering distributed generation resources and energy storage in a small standalone power system. On account of the Kyoto Protocol and Copenhagen Accord, wind and photovoltaic (PV powers are considered as clean and renewable energies. In this study, a genetic algorithm (GA was used to determine the optimal capacities of wind-turbine-generators, PV, diesel generators and energy storage in a small standalone power system. The investment costs (installation, unit and maintenance costs of the distributed generation resources and energy storage and the cost of fuel for the diesel generators were minimized while the reliability requirement and CO2 emission limit were fulfilled. The renewable sources and loads were modeled by random variables because of their uncertainties. The equality and inequality constraints in the genetic algorithms were treated by cumulant effects and cumulative probability of random variables, respectively. The IEEE reliability data for an 8760 h load profile with a 150 kW peak load were used to demonstrate the applicability of the proposed method.

40 CFR 273.53 - Storage time limits.

Science.gov (United States)

2010-07-01

...) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Universal Waste Transporters § 273.53 Storage time limits. (a) A universal waste transporter may only store the universal waste at a universal waste transfer facility for ten days or less. (b) If a universal waste transporter stores universal waste for...

Core--strategy leading to high reversible hydrogen storage capacity for NaBH4.

Science.gov (United States)

Christian, Meganne L; Aguey-Zinsou, Kondo-François

2012-09-25

Owing to its high storage capacity (10.8 mass %), sodium borohydride (NaBH(4)) is a promising hydrogen storage material. However, the temperature for hydrogen release is high (>500 °C), and reversibility of the release is unachievable under reasonable conditions. Herein, we demonstrate the potential of a novel strategy leading to high and stable hydrogen absorption/desorption cycling for NaBH(4) under mild pressure conditions (4 MPa). By an antisolvent precipitation method, the size of NaBH(4) particles was restricted to a few nanometers (hydrogen at 400 °C. Further encapsulation of these nanoparticles upon reaction of nickel chloride at their surface allowed the synthesis of a core--shell nanostructure, NaBH(4)@Ni, and this provided a route for (a) the effective nanoconfinement of the melted NaBH(4) core and its dehydrogenation products, and (b) reversibility and fast kinetics owing to short diffusion lengths, the unstable nature of nickel borohydride, and possible modification of reaction paths. Hence at 350 °C, a reversible and steady hydrogen capacity of 5 mass % was achieved for NaBH(4)@Ni; 80% of the hydrogen could be desorbed or absorbed in less than 60 min, and full capacity was reached within 5 h. To the best of our knowledge, this is the first time that such performances have been achieved with NaBH(4). This demonstrates the potential of the strategy in leading to major advancements in the design of effective hydrogen storage materials from pristine borohydrides.

Capacity enhancement of aqueous borohydride fuels for hydrogen storage in liquids

Energy Technology Data Exchange (ETDEWEB)

Schubert, David; Neiner, Doinita [U.S. Borax Inc., Rio Tinto, Greenwood Village, CO (United States); Bowden, Mark [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA (United States); Whittemore, Sean; Holladay, Jamie [Pacific Northwest National Laboratory, Richland, WA (United States); Huang, Zhenguo [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2500 (Australia); Autrey, Tom [Pacific Northwest National Laboratory, Richland, WA (United States)

2015-10-05

Highlights: • Adjusting ratio of Q = Na/B will maximize H{sub 2} storage capacity of liquid carrier. • Mixtures of hydrolysis products are desirable to maximize solubility. • 6.5 wt.% hydrogen and remains liquid from beginning to end. - Abstract: In this work we demonstrate enhanced hydrogen storage capacities through increased solubility of sodium borate product species in aqueous media achieved by adjusting the sodium (NaOH) to boron (B(OH){sub 3}) ratio, i.e., M/B, to obtain a distribution of polyborate anions. For a 1:1 mol ratio of NaOH to B(OH){sub 3}, M/B = 1, the ratio of the hydrolysis product formed from NaBH{sub 4} hydrolysis, the sole borate species formed and observed by {sup 11}B NMR is sodium metaborate, NaB(OH){sub 4}. When the ratio is 1:3 NaOH to B(OH){sub 3}, M/B = 0.33, a mixture of borate anions is formed and observed as a broad peak in the {sup 11}B NMR spectrum. The complex polyborate mixture yields a metastable solution that is difficult to crystallize. Given the enhanced solubility of the polyborate mixture formed when M/B = 0.33 it should follow that the hydrolysis of sodium octahydrotriborate, NaB{sub 3}H{sub 8}, can provide a greater storage capacity of hydrogen for fuel cell applications compared to sodium borohydride while maintaining a single phase. Accordingly, the hydrolysis of a 23 wt.% NaB{sub 3}H{sub 8} solution in water yields a solution having the same complex polyborate mixture as formed by mixing a 1:3 M ratio of NaOH and B(OH){sub 3} and releases >8 eq of H{sub 2}. By optimizing the M/B ratio a complex mixture of soluble products, including B{sub 3}O{sub 3}(OH){sub 5}{sup 2−}, B{sub 4}O{sub 5}(OH){sub 4}{sup 2−}, B{sub 3}O{sub 3}(OH){sub 4}{sup −}, B{sub 5}O{sub 6}(OH){sub 4}{sup −} and B(OH){sub 3}, can be maintained as a single liquid phase throughout the hydrogen release process. Consequently, hydrolysis of NaB{sub 3}H{sub 8} can provide a 40% increase in H{sub 2} storage density compared to the hydrolysis

European transition to a low carbon electricity system using a mix of variable renewable energies: carbon saving trajectories as functions of production and storage capacity.

Science.gov (United States)

Francois, Baptiste; Creutin, Jean-Dominique

2016-04-01

Today, most of the produced energy is generated from fossil energy sources (i.e. coal, petroleum). As a result, the energy sector is still the main source of greenhouse gas in the atmosphere. For limiting greenhouse gas emission, a transition from fossil to renewable energy is required, increasing gradually the fraction energy coming from variable renewable energy (i.e. solar power, wind power and run-of-the river hydropower, hereafter denoted as VRE). VRE penetration, i.e. the percentage of demand satisfied by variable renewables assuming no storage capacity, is hampered by their variable and un-controllable features. Many studies show that combining different VRE over space smoothes their variability and increases their global penetration by a better match of demand fluctuations. When the demand is not fully supplied by the VRE generation, backup generation is required from stored energy (mostly from dams) or fossil sources, the latter being associated with high greenhouse gas emission. Thus the VRE penetration is a direct indicator of carbon savings and basically depends on the VRE installed capacity, its mix features, and on the installed storage capacity. In this study we analyze the European transition to a low carbon electricity system. Over a selection of representative regions we analyze carbon saving trajectories as functions of VRE production and storage capacities for different scenarios mixing one to three VRE with non-renewables. We show substantial differences between trajectories when the mix of sources is far from the local optimums, when the storage capacity evolves. We bring new elements of reflection about the effect of transport grid features from local independent systems to a European "copper plate". This work is part of the FP7 project COMPLEX (Knowledge based climate mitigation systems for a low carbon economy; Project FP7-ENV-2012 number: 308601; http://www.complex.ac.uk/).

Flower-like SnO2/graphene composite for high-capacity lithium storage

International Nuclear Information System (INIS)

Liu Hongdong; Huang Jiamu; Li Xinlu; Liu Jia; Zhang Yuxin; Du Kun

2012-01-01

Flower-like SnO 2 /graphene composite is synthesized by a simple hydrothermal method for high-capacity lithium storage. The as-prepared products are characterized by XRD, FTIR, FESEM, TGA and Nitrogen adsorption/desorption. The electrochemical performance of the flower-like SnO 2 /graphene composite is measured by cyclic voltammetry and galvanostatic charge/discharge cycling. The results show that the flower-like SnO 2 nanorod clusters are 800 nm in size and homogeneously adhere on graphene sheets. The flower-like SnO 2 /graphene composite displays superior Li-battery performance with large reversible capacity, excellent cyclic performance and good rate capability.

Assessing storage adequacy

International Nuclear Information System (INIS)

Amirault, P.

2004-01-01

Government policy encourages the use of natural gas. It is expected that liquefied natural gas (LNG) and Arctic gas will make up 20 to 25 per cent of supply. This presentation provided an outlook of storage value based on a technical analysis by the National Petroleum Counsel (NPC) report. A moderately robust growth is expected in the residential and commercial load which may be partially offset by robust growth in electricity. The net result is an increase in storage requirements. It was concluded that there is a strong case for growth in storage demand but a lack of good sites for additional capacity. This will lead to higher storage values. The NPC sees the need for 1 Tcf more storage use by 2025, of which 700 Bcf will need to come from new storage. In particular, current storage levels may not be sufficient to meet a colder than normal winter, and deliverability is affected by field inventory. Most storage capacity was built before 1985, mostly by regulated entities. It is expected that only 250 to 400 Bcf will be added over the next 25 years in North America. If storage becomes scarce, prices will move to the marginal cost of new additions, and the upper limit on price will be determined by salt cavern storage. An increase of $1.00 in the price of leasing storage would add about $0.11 to the average price of consumed gas. tabs., figs

Experimental and Numerical Study of Effect of Thermal Management on Storage Capacity of the Adsorbed Natural Gas Vessel

KAUST Repository

Ybyraiymkul, Doskhan; Ng, Kim Choon; Кaltayev, Aidarkhan

2017-01-01

One of the main challenges in the adsorbed natural gas (ANG) storage system is the thermal effect of adsorption, which significantly lowers storage capacity. These challenges can be solved by efficient thermal management system. In this paper

Experimental and Numerical Study of Effect of Thermal Management on Storage Capacity of the Adsorbed Natural Gas Vessel

KAUST Repository

Ybyraiymkul, Doskhan

2017-07-08

One of the main challenges in the adsorbed natural gas (ANG) storage system is the thermal effect of adsorption, which significantly lowers storage capacity. These challenges can be solved by efficient thermal management system. In this paper, influence of thermal management on storage capacity of the ANG vessel was studied experimentally and numerically. 3D numerical model was considered in order to understand heat transfer phenomena and analyze influence of thermal control comprehensively. In addition, a detailed 2D axisymmetric unit cell model of adsorbent layer with heat exchanger was developed, followed by optimization of heat exchanging device design to minimize volume occupied by fins and tubes. Heat transfer, mass transfer and adsorption kinetics, which occur in ANG vessel during charging process, are accounted for in models. Nelder-Mead method is implemented to obtain the geometrical parameters, which lead to the optimal characteristics of heat exchange. A new optimized configuration of ANG vessel was developed with compact heat exchanger. Results show that storage capacity of the ANG vessel increased significantly due to lowering of heat exchanger volume for 3 times from 13.5% to 4.3% and effective temperature control.

A risk management approach to double-shell tank waste volume versus storage capacity

Energy Technology Data Exchange (ETDEWEB)

Coles, G.A. [Westinghouse Hanford Co., Richland, WA (United States); Thurkow, T.J.; Fritz, R.L.; Nuhlestein, L.O.; Allen, M.R.; Stuart, R.J. [ARES Corp. (United States)

1996-01-01

A risk-based assessment of the overall waste volume versus double-shell tank storage capacity was conducted to develop fallback positions for projections where the waste volume was at a high risk of exceeding capacity. This study was initiated to provide that assessment. A working simulation model was the primary deliverable of this study. The model validates the approach and demonstrates that simulation analysis can provide a method of tracking uncertainties in available data, assessing probabilities, and serves as a tool to be used by management to determine the consequences of various off-normal occurrences.

A risk management approach to double-shell tank waste volume versus storage capacity

International Nuclear Information System (INIS)

Coles, G.A.; Thurkow, T.J.; Fritz, R.L.; Nuhlestein, L.O.; Allen, M.R.; Stuart, R.J.

1996-01-01

A risk-based assessment of the overall waste volume versus double-shell tank storage capacity was conducted to develop fallback positions for projections where the waste volume was at a high risk of exceeding capacity. This study was initiated to provide that assessment. A working simulation model was the primary deliverable of this study. The model validates the approach and demonstrates that simulation analysis can provide a method of tracking uncertainties in available data, assessing probabilities, and serves as a tool to be used by management to determine the consequences of various off-normal occurrences

Antioxidant capacity, phenolic and vitamin C contents of quinoa (Chenopodium quinoa Willd. as affected by sprouting and storage conditions

Directory of Open Access Journals (Sweden)

Maura N. Laus

2017-03-01

Full Text Available Antioxidant capacity (AC of quinoa (Chenopodium quinoa Willd. cv. Real seeds and sprouts obtained after 4 days of seed germination at 20°C and 70% humidity was evaluated using trolox equivalent antioxidant capacity (TEAC and oxygen radical absorbance capacity (ORAC assays, able to highlight reducing activity and peroxyl radical scavenging capacity, respectively; phenolic content (PC was also measured. Both TEAC and ORAC assays revealed a significantly higher (about 2- and 2.8-fold, respectively AC of 4-day-old sprouts compared to seeds; consistently, also PC values of sprouts resulted about 2.6 times higher than seeds. In order to investigate the influence of storage on AC and PC, as well as on vitamin C content (VCC, 4-day-old sprouts were subjected for 7 days at 5°C to three different conditions of controlled atmosphere storage (CAS compared with air. Interestingly, whatever the CAS conditions, storage of quinoa sprouts up to 7 days induced an increase of AC evaluated in terms of reducing activity by TEAC assay. Consistently, an increase of PC and VCC was measured during storage, positively correlated to TEAC values. Moreover, a decrease of peroxyl radical scavenging activity, measured by ORAC, was observed after 7 days of storage, in accordance with a shift of AC towards the reducing activity component. Overall, these findings indicate that sprouting approach using quinoa may provide highly antioxidant-enriched seedlings that may improve nutritional quality of diet or of functional foods. Interestingly, antioxidant properties of quinoa sprouts may be deeply influenced by storage, able to increase reducing activity by increasing phenols and vitamin C.

Model predictive control for power flows in networks with limited capacity

DEFF Research Database (Denmark)

Biegel, Benjamin; Stoustrup, Jakob; Bendtsen, Jan Dimon

2012-01-01

this problem can be formulated as an optimization problem, leading directly to the design of a model predictive controller. Using this scheme, we are able to incorporate predictions of future consumption and exploit knowledge of link limitations such that the intelligent consumers are utilized ahead of time......We consider an interconnected network of consumers powered through an electrical grid of limited capacity. A subset of the consumers are intelligent consumers and have the ability to store energy in a controllable fashion; they can be filled and emptied as desired under power and capacity...... limitations. We address the problem of maintaining power balance between production and consumption using the intelligent consumers to ensure smooth power consumption from the grid. Further, certain capacity limitations to the links interconnecting the consumers must be honored. In this paper, we show how...

Hydrogen Storage Capacity of Tetrahydrofuran and Tetra-N-Butylammonium Bromide Hydrates Under Favorable Thermodynamic Conditions

Directory of Open Access Journals (Sweden)

Joshua T. Weissman

2017-08-01

Full Text Available An experimental study was conducted to evaluate the feasibility of employing binary hydrates as a medium for H2 storage. Two reagents, tetrahydrofuran (THF and tetra-n-butylammonium bromide (TBAB, which had been reported previously to have potential to form binary hydrates with H2 under favorable conditions (i.e., low pressures and high temperatures, were investigated using differential scanning calorimetry and Raman spectroscopy. A scale-up facility was employed to quantify the hydrogen storage capacity of THF binary hydrate. Gas chromatography (GC and pressure drop analyses indicated that the weight percentages of H2 in hydrate were less than 0.1%. The major conclusions of this investigation were: (1 H2 can be stored in binary hydrates at relatively modest pressures and temperatures which are probably feasible for transportation applications; and (2 the storage capacity of H2 in binary hydrate formed from aqueous solutions of THF over a concentration range extending from 2.78 to 8.34 mol % and at temperatures above 263 K and pressures below 11 MPa was <0.1 wt %.

Distributed generation, storage, demand response and energy efficiency as alternatives to grid capacity enhancement

International Nuclear Information System (INIS)

Poudineh, Rahmatallah; Jamasb, Tooraj

2014-01-01

The need for investment in capital intensive electricity networks is on the rise in many countries. A major advantage of distributed resources is their potential for deferring investments in distribution network capacity. However, utilizing the full benefits of these resources requires addressing several technical, economic and regulatory challenges. A significant barrier pertains to the lack of an efficient market mechanism that enables this concept and also is consistent with business model of distribution companies under an unbundled power sector paradigm. This paper proposes a market-oriented approach termed as “contract for deferral scheme” (CDS). The scheme outlines how an economically efficient portfolio of distributed generation, storage, demand response and energy efficiency can be integrated as network resources to reduce the need for grid capacity and defer demand driven network investments. - Highlights: • The paper explores a practical framework for smart electricity distribution grids. • The aim is to defer large capital investments in the network by utilizing and incentivising distributed generation, demand response, energy efficiency and storage as network resources. • The paper discusses a possible new market model that enables integration of distributed resources as alternative to grid capacity enhancement

Enhanced hydrogen storage capacity of Ni/Sn-coated MWCNT nanocomposites

Science.gov (United States)

Varshoy, Shokufeh; Khoshnevisan, Bahram; Behpour, Mohsen

2018-02-01

The hydrogen storage capacity of Ni-Sn, Ni-Sn/multi-walled carbon nanotube (MWCNT) and Ni/Sn-coated MWCNT electrodes was investigated by using a chronopotentiometry method. The Sn layer was electrochemically deposited inside pores of nanoscale Ni foam. The MWCNTs were put on the Ni-Sn foam with nanoscale porosities using an electrophoretic deposition method and coated with Sn nanoparticles by an electroplating process. X-ray diffraction and energy dispersive spectroscopy results indicated that the Sn layer and MWCNTs are successfully deposited on the surface of Ni substrate. On the other hand, a field-emission scanning electron microscopy technique revealed the morphology of resulting Ni foam, Ni-Sn and Ni-Sn/MWCNT electrodes. In order to measure the hydrogen adsorption performed in a three electrode cell, the Ni-Sn, Ni-Sn/MWCNT and Ni/Sn-coated MWCNT electrodes were used as working electrodes whereas Pt and Ag/AgCl electrodes were employed as counter and reference electrodes, respectively. Our results on the discharge capacity in different electrodes represent that the Ni/Sn-coated MWCNT has a maximum discharge capacity of ˜30 000 mAh g-1 for 20 cycles compared to that of Ni-Sn/MWCNT electrodes for 15 cycles (˜9500 mAh g-1). By increasing the number of cycles in a constant current, the corresponding capacity increases, thereby reaching a constant amount for 20 cycles.

The role of storage capacity in coping with intra-annual runoff variability on a global scale

Science.gov (United States)

Gaupp, Franziska; Hall, Jim; Dadson, Simon

2015-04-01

Intra-annual variability poses a risk to water security in many basins as runoff is unevenly distributed over the year. Areas such as Northern Africa, Australia and the South-Western USA are characterized by a high coefficient of variability of monthly runoff. Analyzing the global risk of water scarcity, this study examines 680 basin-country units (BCUs) (403 river basins divided by country borders). By calculating the water balance for each BCU, the interplay of runoff on the one hand and domestic, industrial and environmental water needs on the other hand is shown. In contrast to other studies on average water scarcity, this work focuses on variability of water supply as metrics based on annual average water availability and demand can underestimate the risk of scarcity. The model is based on the assumption that each country-basin with sub-basins and tributaries can be treated as one single reservoir with storage capacity aggregated over that BCU. It includes surface runoff and the possibility to withdraw groundwater as water supply. The storage capacity of each BCU represents the ability to transfer water from wet months to dry months in order to buffer and cope with intra-annual water supply variability and to meet total water demand. Average monthly surface runoff per country-basin for the period 1979 to 2012 is derived from outcomes of the hydrological model Mac-PDM. Mac-PDM is forced with monthly ERAI-Interim reanalysis climate data on a one degree resolution. Groundwater withdrawal capacity, total water demand and storage capacity are taken from the IMPACT model provided by the International Food Research Institute (IFPRI). Storage refers to any kind of surface reservoir whose water can be managed and used for human activities in the industrial, domestic and agricultural sectors. Groundwater withdrawal capacity refers to the technological capacity to pump water rather than the amount of groundwater available. Total water demand includes consumptive water

Limited communication capacity unveils strategies for human interaction

Science.gov (United States)

Miritello, Giovanna; Lara, Rubén; Cebrian, Manuel; Moro, Esteban

2013-06-01

Connectivity is the key process that characterizes the structural and functional properties of social networks. However, the bursty activity of dyadic interactions may hinder the discrimination of inactive ties from large interevent times in active ones. We develop a principled method to detect tie de-activation and apply it to a large longitudinal, cross-sectional communication dataset (~19 months, ~20 million people). Contrary to the perception of ever-growing connectivity, we observe that individuals exhibit a finite communication capacity, which limits the number of ties they can maintain active in time. On average men display higher capacity than women, and this capacity decreases for both genders over their lifespan. Separating communication capacity from activity reveals a diverse range of tie activation strategies, from stable to exploratory. This allows us to draw novel relationships between individual strategies for human interaction and the evolution of social networks at global scale.

An information capacity limitation of visual short-term memory.

Science.gov (United States)

Sewell, David K; Lilburn, Simon D; Smith, Philip L

2014-12-01

Research suggests that visual short-term memory (VSTM) has both an item capacity, of around 4 items, and an information capacity. We characterize the information capacity limits of VSTM using a task in which observers discriminated the orientation of a single probed item in displays consisting of 1, 2, 3, or 4 orthogonally oriented Gabor patch stimuli that were presented in noise for 50 ms, 100 ms, 150 ms, or 200 ms. The observed capacity limitations are well described by a sample-size model, which predicts invariance of ∑(i)(d'(i))² for displays of different sizes and linearity of (d'(i))² for displays of different durations. Performance was the same for simultaneous and sequentially presented displays, which implicates VSTM as the locus of the observed invariance and rules out explanations that ascribe it to divided attention or stimulus encoding. The invariance of ∑(i)(d'(i))² is predicted by the competitive interaction theory of Smith and Sewell (2013), which attributes it to the normalization of VSTM traces strengths arising from competition among stimuli entering VSTM. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Analysis of the Storage Capacity in an Aggregated Heat Pump Portfolio

DEFF Research Database (Denmark)

Nielsen, Kirsten Mølgaard; Andersen, Palle; Pedersen, Tom Søndergård

2015-01-01

Energy storages connected to the power grid will be of great importance in the near future. A pilot project has investigated more than 100 single family houses with heat pumps all connected to the internet. The houses have large heat capacities and it is possible to move energy consumption to sui...... (scheduling) algorithm. The properties of this scheduling are investigated in the paper especially the flexibility and ability to trade on the intra-day regulating market is in focus....

PC-Cluster based Storage System Architecture for Cloud Storage

OpenAIRE

Yee, Tin Tin; Naing, Thinn Thu

2011-01-01

Design and architecture of cloud storage system plays a vital role in cloud computing infrastructure in order to improve the storage capacity as well as cost effectiveness. Usually cloud storage system provides users to efficient storage space with elasticity feature. One of the challenges of cloud storage system is difficult to balance the providing huge elastic capacity of storage and investment of expensive cost for it. In order to solve this issue in the cloud storage infrastructure, low ...

Capacity Optimization of Renewable Energy Sources and Battery Storage in an Autonomous Telecommunication Facility

DEFF Research Database (Denmark)

Dragicevic, Tomislav; Pandžić, Hrvoje; Škrlec, Davor

2014-01-01

This paper describes a robust optimization approach to minimize the total cost of supplying a remote telecommunication station exclusively by renewable energy sources (RES). Due to the intermittent nature of RES, such as photovoltaic (PV) panels and small wind turbines, they are normally supported...... by a central energy storage system (ESS), consisting of a battery and a fuel cell. The optimization is carried out as a robust mixed-integer linear program (RMILP), and results in different optimal solutions, depending on budgets of uncertainty, each of which yields different RES and storage capacities...

CO2 point sources and subsurface storage capacities for CO2 in aquifers in Norway

International Nuclear Information System (INIS)

Boee, Reidulv; Magnus, Christian; Osmundsen, Per Terje; Rindstad, Bjoern Ivar

2002-01-01

The GESTCO project comprises a study of the distribution and coincidence of thermal CO 2 emission sources and location/quality of geological storage capacity in Europe. Four of the most promising types of geological storage are being studied. 1. Onshore/offshore saline aquifers with or without lateral seal. 2. Low entalpy geothermal reservoirs. 3. Deep methane-bearing coal beds and abandoned coal and salt mines. 4. Exhausted or near exhausted hydrocarbon structures. In this report we present an inventory of CO 2 point sources in Norway (1999) and the results of the work within Study Area C: Deep saline aquifers offshore/near shore Northern and Central Norway. Also offshore/near shore Southern Norway has been included while the Barents Sea is not described in any detail. The most detailed studies are on the Tilje and Aare Formations on the Troendelag Platform off Mid-Norway and on the Sognefjord, Fensfjord and Krossfjord Formations, southeast of the Troll Field off Western Norway. The Tilje Formation has been chosen as one of the cases to be studied in greater detail (numerical modelling) in the project. This report shows that offshore Norway, there are concentrations of large CO 2 point sources in the Haltenbanken, the Viking Graben/Tampen Spur area, the Southern Viking Graben and the central Trough, while onshore Norway there are concentrations of point sources in the Oslofjord/Porsgrund area, along the coast of western Norway and in the Troendelag. A number of aquifers with large theoretical CO 2 storage potential are pointed out in the North Sea, the Norwegian Sea and in the Southern Barents Sea. The storage capacity in the depth interval 0.8 - 4 km below sea level is estimated to be ca. 13 Gt (13000000000 tonnes) CO 2 in geological traps (outside hydrocarbon fields), while the storage capacity in aquifers not confined to traps is estimated to be at least 280 Gt CO 2 . (Author)

Nuclear waste: Is there a need for federal interim storage

International Nuclear Information System (INIS)

1989-01-01

The Congress created the Monitored Retrievable Storage Review Commission to provide a report on the need for a Federal monitored retrievable storage facility (MRS) as part of the Nation's nuclear waste management system. The Commission concludes that the MRS as presently described in the law, which links the capacity and schedule of operation of the MRS to a permanent geologic repository, cannot be justified. The Commission finds, however, that while no single factor would favor an MRS over the No-MRS option, cumulatively the advantages of an MRS would justify the building of an MRS if: there were no linkages between the MRS and the repository; the MRS could be constructed at an early date; and the opening of the repository were delayed considerably beyond its presently scheduled date of operation. The Commission therefore recommends that the Congress take the following actions: Authorize construction of a Federal Emergency Storage facility with a capacity limit of 2,000 metric tons of uranium; Authorize construction of a User-Funded Interim Storage facility with a capacity limit of 5,000 metric tons of uranium; Reconsider the subject of interim storage by the year 2000

Collateral and the limits of debt capacity: theory and evidence

NARCIS (Netherlands)

Giambona, E.; Mello, A.S.; Riddiough, T.

2012-01-01

This paper considers how collateral is used to finance a going concern, and demonstrates with theory and evidence that there are effective limits to debt capacity and the kinds of claims that are issued to deploy that debt capacity. The theory shows that firms with (unobservably) better quality

Anthocyanins, phenolics and antioxidant capacity after fresh storage of blueberry treated with edible coatings.

Science.gov (United States)

Chiabrando, Valentina; Giacalone, Giovanna

2015-05-01

The influence of different edible coatings on total phenolic content, total anthocyanin and antioxidant capacity in highbush blueberry (Vaccinium corymbosum L. cv Berkeley and O'Neal) was investigated, mainly for industrial applications. Also titratable acidity, soluble solids content, firmness and weight loss of berries were determined at harvest and at 15-day intervals during 45 storage days at 0 °C, in order to optimize coating composition. Application of chitosan coating delayed the decrease in anthocyanin content, phenolic content and antioxidant capacity. Coating samples showed no significant reduction in the weight loss during storage period. In cv Berkeley, the use of alginate coating showed a positive effect on firmness, titratable acidity and maintained surface lightness of treated berries. In cv O'Neal, no significant differences in total soluble solids content were found, and the chitosan-coated berries showed the minimum firmness losses. In both cultivars, the addition of chitosan to coatings decreases the microbial growth rate.

Multi-Stage Transportation Problem With Capacity Limit

OpenAIRE

I. Brezina; Z. Čičková; J. Pekár; M. Reiff

2010-01-01

The classical transportation problem can be applied in a more general way in practice. Related problems as Multi-commodity transportation problem, Transportation problems with different kind of vehicles, Multi-stage transportation problems, Transportation problem with capacity limit is an extension of the classical transportation problem considering the additional special condition. For solving such problems many optimization techniques (dynamic programming, linear programming, special algor...

Short-Term Memory Limitations in Children: Capacity or Processing Deficits?

Science.gov (United States)

Chi, Michelene T. H.

1976-01-01

Evaluates the assertion that short-term memory (STM) capacity increases with age and concludes that the STM capacity limitation in children is due to the deficits in the processing strategies and speeds, which presumably improve with age through cumulative learning. (JM) Available from: Memory and Cognition, Psychonomic Society, 1018 West 34…

Carbon hybridized halloysite nanotubes for high-performance hydrogen storage capacities

Science.gov (United States)

Jin, Jiao; Fu, Liangjie; Yang, Huaming; Ouyang, Jing

2015-01-01

Hybrid nanotubes of carbon and halloysite nanotubes (HNTs) with different carbon:HNTs ratio were hydrothermally synthesized from natural halloysite and sucrose. The samples display uniformly cylindrical hollow tubular structure with different morphologies. These hybrid nanotubes were concluded to be promising medium for physisorption-based hydrogen storage. The hydrogen adsorption capacity of pristine HNTs was 0.35% at 2.65 MPa and 298 K, while that of carbon coated HNTs with the pre-set carbon:HNTs ratio of 3:1 (3C-HNTs) was 0.48% under the same condition. This carbon coated method could offer a new pattern for increasing the hydrogen adsorption capacity. It was also possible to enhance the hydrogen adsorption capacity through the spillover mechanism by incorporating palladium (Pd) in the samples of HNTs (Pd-HNTs) and 3C-HNTs (Pd-3C-HNTs and 3C-Pd-HNTs are the samples with different location of Pd nanoparticles). The hydrogen adsorption capacity of the Pd-HNTs was 0.50% at 2.65 MPa and 298 K, while those of Pd-3C-HNTs and 3C-Pd-HNTs were 0.58% and 0.63%, respectively. In particular, for this spillover mechanism of Pd-carbon-HNTs ternary system, the bidirectional transmission of atomic and molecular hydrogen (3C-Pd-HNTs) was concluded to be more effective than the unidirectional transmission (Pd-3C-HNTs) in this work for the first time. PMID:26201827

Dynamic Heat Storage and Cooling Capacity of a Concrete Deck with PCM and Thermally Activated Building System

DEFF Research Database (Denmark)

Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

2012-01-01

This paper presents a heat storage and cooling concept that utilizes a phase change material (PCM) and a thermally activated building system (TABS) implemented in a hollow core concrete deck. Numerical calculations of the dynamic heat storage capacity of the hollow core concrete deck element...... in the article highlight the potential of using TABS and PCM in a prefabricated concrete deck element....

Estimates of Storage Capacity of Multilayer Perceptron with Threshold Logic Hidden Units.

Science.gov (United States)

Kowalczyk, Adam

1997-11-01

We estimate the storage capacity of multilayer perceptron with n inputs, h(1) threshold logic units in the first hidden layer and 1 output. We show that if the network can memorize 50% of all dichotomies of a randomly selected N-tuple of points of R(n) with probability 1, then Nmemory capacity (in the sense of Cover) between nh(1)+1 and 2(nh(1)+1) input patterns and for the most efficient networks in this class between 1 and 2 input patterns per connection. Comparing these results with the recent estimates of VC-dimension we find that in contrast to a single neuron case, the VC-dimension exceeds the capacity for a sufficiently large n and h(1). The results are based on the derivation of an explicit expression for the number of dichotomies which can be implemented by such a network for a special class of N-tuples of input patterns which has a positive probability of being randomly chosen.

NV Energy Electricity Storage Valuation

Energy Technology Data Exchange (ETDEWEB)

Ellison, James F.; Bhatnagar, Dhruv; Samaan, Nader A.; Jin, Chunlian

2013-06-30

This study examines how grid-level electricity storage may benet the operations of NV Energy in 2020, and assesses whether those benets justify the cost of the storage system. In order to determine how grid-level storage might impact NV Energy, an hourly production cost model of the Nevada Balancing Authority (\\BA") as projected for 2020 was built and used for the study. Storage facilities were found to add value primarily by providing reserve. Value provided by the provision of time-of-day shifting was found to be limited. If regulating reserve from storage is valued the same as that from slower ramp rate resources, then it appears that a reciprocating engine generator could provide additional capacity at a lower cost than a pumped storage hydro plant or large storage capacity battery system. In addition, a 25-MW battery storage facility would need to cost $650/kW or less in order to produce a positive Net Present Value (NPV). However, if regulating reserve provided by storage is considered to be more useful to the grid than that from slower ramp rate resources, then a grid-level storage facility may have a positive NPV even at today's storage system capital costs. The value of having storage provide services beyond reserve and time-of-day shifting was not assessed in this study, and was therefore not included in storage cost-benefit calculations.

Carrying capacity: the tradition and policy implications of limits

Directory of Open Access Journals (Sweden)

Virginia Deane Abernethy

2001-01-01

Full Text Available ABSTRACT: Within just the last few centuries, science and technology have enlarged human capabilities and population size until humans now take, for their own use, nearly half of the Earth's net terrestrial primary production. An ethical perspective suggests that potentials to alter, or further increase, humanity's use of global resources should be scrutinized through the lenses of self-interested foresightedness and respect for non-human life. Without overtly invoking ethics, studies of the carrying capacity achieve just this objective. Carrying capacity is an ecological concept that expresses the relationship between a population and the natural environment on which it depends for ongoing sustenance. Carrying capacity assumes limits on the number of individuals that can be supported at a given level of consumption without degrading the environment and, therefore, reducing future carrying capacity. That is, carrying capacity addresses long-term sustainability. Worldviews differ in the importance accorded to the carrying capacity concept. This paper addresses three worldviews - ecological, romantic, and entrepreneurial - and explores the ethics and the policy implications of their contrasting perspectives.

Boar sperm storage capacity of BTS and Androhep Plus: viability, motility, capacitation, and tyrosine phosphorylation.

Science.gov (United States)

Dubé, Charlotte; Beaulieu, Martin; Reyes-Moreno, Carlos; Guillemette, Christine; Bailey, Janice L

2004-09-01

Androhep Plus, a long-term extender (up to 7 days) and Beltsville Thawing Solution (BTS), a short-term extender (up to 3 days), are commonly used for liquid storage of porcine semen. To test the hypothesis that modifications in sperm viability, motility, chlortetracycline (CTC) fluorescence patterns, and protein tyrosine phosphorylation occur during semen storage in extenders, we compared these end points at different periods of storage in either Androhep Plus or BTS. Sperm from five boars were assessed daily over 12 days of storage (n = 5 ejaculates from different boars). Viability was not different (P extenders, except on Day 2, when Androhep Plus maintained better viability. Differences in the percentage of motile (total) sperm due to extender were evident on Days 2, 4, 5, and 6, when Androhep Plus was superior to BTS (P extender as early as Day 2; storage in Androhep Plus induced higher levels of pattern B sperm (P extenders; these may affect the fertilizing capacity of the semen.

Analysis of the influence of input data uncertainties on determining the reliability of reservoir storage capacity

Directory of Open Access Journals (Sweden)

Marton Daniel

2015-12-01

Full Text Available The paper contains a sensitivity analysis of the influence of uncertainties in input hydrological, morphological and operating data required for a proposal for active reservoir conservation storage capacity and its achieved values. By introducing uncertainties into the considered inputs of the water management analysis of a reservoir, the subsequent analysed reservoir storage capacity is also affected with uncertainties. The values of water outflows from the reservoir and the hydrological reliabilities are affected with uncertainties as well. A simulation model of reservoir behaviour has been compiled with this kind of calculation as stated below. The model allows evaluation of the solution results, taking uncertainties into consideration, in contributing to a reduction in the occurrence of failure or lack of water during reservoir operation in low-water and dry periods.

Engineering program in order to increase the irradiated fuel storage capacity in pool facilities of Juragua

International Nuclear Information System (INIS)

Rodriguez R, J.

1996-01-01

In 1993, a technical program in the spent fuel storage area of Nuclear Plant Juragua was launched. Such a program tries to carry out an engineering assessment of the possibility of increasing the spent fuel storage capacity in pool storage facilities by using high density racks (re-racking) instead of the original (non-compact) ones. The purpose of the above-mentioned program is to evaluate possible solutions that can be applied to the construction works prior to plant operation. The first stage of the program for the 1994-95 period is an ongoing Engineering-Economic Feasibility Study (EEFS), which endeavors to examine the capabilities of the reloading pool in Unit-1 Reactor building and long-term storage pool in auxiliary building in high density storage conditions. Technical details of the EEFS and reached results and difficulties are described. (author). 5 refs., 2 figs

Technology Assessment of High Capacity Data Storage Systems: Can We Avoid a Data Survivability Crisis?

Science.gov (United States)

Halem, M.; Shaffer, F.; Palm, N.; Salmon, E.; Raghavan, S.; Kempster, L.

1998-01-01

This technology assessment of long-term high capacity data storage systems identifies an emerging crisis of severe proportions related to preserving important historical data in science, healthcare, manufacturing, finance and other fields. For the last 50 years, the information revolution, which has engulfed all major institutions of modem society, centered itself on data-their collection, storage, retrieval, transmission, analysis and presentation. The transformation of long term historical data records into information concepts, according to Drucker, is the next stage in this revolution towards building the new information based scientific and business foundations. For this to occur, data survivability, reliability and evolvability of long term storage media and systems pose formidable technological challenges. Unlike the Y2K problem, where the clock is ticking and a crisis is set to go off at a specific time, large capacity data storage repositories face a crisis similar to the social security system in that the seriousness of the problem emerges after a decade or two. The essence of the storage crisis is as follows: since it could take a decade to migrate a peta-byte of data to a new media for preservation, and the life expectancy of the storage media itself is only a decade, then it may not be possible to complete the transfer before an irrecoverable data loss occurs. Over the last two decades, a number of anecdotal crises have occurred where vital scientific and business data were lost or would have been lost if not for major expenditures of resources and funds to save this data, much like what is happening today to solve the Y2K problem. A pr-ime example was the joint NASA/NSF/NOAA effort to rescue eight years worth of TOVS/AVHRR data from an obsolete system, which otherwise would have not resulted in the valuable 20-year long satellite record of global warming. Current storage systems solutions to long-term data survivability rest on scalable architectures

Burnup credit in a dry storage module

International Nuclear Information System (INIS)

Thornton, J.R.

1989-01-01

Comparison of spent fuel storage expansion options available to Oconee Nuclear Station revealed that dry storage could be economically competitive with transshipment and rod consolidation. Economic competitiveness, however, mandated large unit capacity while existing cask handling facilities at Oconee severely limited size and weight. The dry storage concept determined to best satisfy these conflicting criteria is a 24 pressurized water reactor (PWR) fuel assembly capacity NUTECH Horizontal Modular Storage (NUHOMS) system. The Oconee version of the NUHOMS system takes advantage of burnup credit in demonstrating criticality safety. The burnup credit criticality analysis was performed by Duke Power Company's Design Engineering Department. This paper was prepared to summarize the criticality control design features employed in the Oconee NUHOMS-24P DSC basket and to describe the incentives for pursuing a burnup credit design. Principal criticality design parameters, criteria, and analysis methodology are also presented

Nuclear heat-load limits for above-grade storage of solid transuranium wastes

International Nuclear Information System (INIS)

Clontz, B.G.

1978-06-01

Nuclear safety and heat load limits were established for above-grade storage of transuranium (TRU) wastes. Nuclear safety limits were obtained from a study by J.L. Forstner and are summarized. Heat load limits are based on temperature calculations for TRU waste drums stored in concrete containers (hats), and results are summarized. Waste already in storage is within these limits. The limiting factors for individual drum heat load limits were (1) avoidance of temperatures in excess of 190 0 F (decomposition temperature of anion resin) when anion resin is present in a concrete hat, and (2) avoidance of temperatures in excess of 450 0 F (ignition temperature of paper) at any point inside a waste drum. The limiting factor for concrete had heat load limits was avoidance of temperatures in excess of 265 0 F (melt point of high density polyethylene) at the drum liners. A temperature profile for drums and hats filled to recommended limits is shown. Equations and assumptions used were conservative

Traceable components of terrestrial carbon storage capacity in biogeochemical models.

Science.gov (United States)

Xia, Jianyang; Luo, Yiqi; Wang, Ying-Ping; Hararuk, Oleksandra

2013-07-01

Biogeochemical models have been developed to account for more and more processes, making their complex structures difficult to be understood and evaluated. Here, we introduce a framework to decompose a complex land model into traceable components based on mutually independent properties of modeled biogeochemical processes. The framework traces modeled ecosystem carbon storage capacity (Xss ) to (i) a product of net primary productivity (NPP) and ecosystem residence time (τE ). The latter τE can be further traced to (ii) baseline carbon residence times (τ'E ), which are usually preset in a model according to vegetation characteristics and soil types, (iii) environmental scalars (ξ), including temperature and water scalars, and (iv) environmental forcings. We applied the framework to the Australian Community Atmosphere Biosphere Land Exchange (CABLE) model to help understand differences in modeled carbon processes among biomes and as influenced by nitrogen processes. With the climate forcings of 1990, modeled evergreen broadleaf forest had the highest NPP among the nine biomes and moderate residence times, leading to a relatively high carbon storage capacity (31.5 kg cm(-2) ). Deciduous needle leaf forest had the longest residence time (163.3 years) and low NPP, leading to moderate carbon storage (18.3 kg cm(-2) ). The longest τE in deciduous needle leaf forest was ascribed to its longest τ'E (43.6 years) and small ξ (0.14 on litter/soil carbon decay rates). Incorporation of nitrogen processes into the CABLE model decreased Xss in all biomes via reduced NPP (e.g., -12.1% in shrub land) or decreased τE or both. The decreases in τE resulted from nitrogen-induced changes in τ'E (e.g., -26.7% in C3 grassland) through carbon allocation among plant pools and transfers from plant to litter and soil pools. Our framework can be used to facilitate data model comparisons and model intercomparisons via tracking a few traceable components for all terrestrial carbon

Short-term storage evaluation of quality and antioxidant capacity in chestnut-wheat bread.

Science.gov (United States)

Rinaldi, Massimiliano; Paciulli, Maria; Dall'Asta, Chiara; Cirlini, Martina; Chiavaro, Emma

2015-01-01

Bread traditionally made from wheat is now often supplemented with alternative functional ingredients as chestnut flours; no data have been previously published about the staling of chestnut-containing bread. Thus short-term storage (3 days) for chestnut flour-supplemented soft wheat bread is evaluated by means of selected physicochemical properties (i.e. water dynamics, texture, colour, crumb grain characteristic, total antioxidant capacity). Bread prepared with a 20:80 ratio of chestnut:soft wheat flours maintained its moisture content in both crust and crumb. Crumb hardness, after baking, was found to be significantly higher than that of the soft wheat bread; it did not change during storage, whereas it significantly increased in the control bread until the end of the shelf life. The supplemented bread presented a heterogeneous crumb structure, with a significant decrease in the largest pores during shelf life, relative to the shrinkage of crumb grain. The control exhibited a significant redistribution of crumb holes, with a decrease in the smallest grain classes and an increase in the intermediate ones, most likely caused by cell wall thickening. The colour of the crumb remained unaltered in both breads. The crust of the control presented a significant decrease of a* (redness) and that of the supplemented bread exhibited a decrease of b* (yellowness). The antioxidant capacity was detected after day 1 of storage in the chestnut flour bread only. Chestnut flour supplementation could represent a feasible way of producing bread with improved characteristics, not only just after baking but also during shelf life. © 2014 Society of Chemical Industry.

Seasonal evolution of diffusional limitations and photosynthetic capacity in olive under drought.

Science.gov (United States)

Diaz-Espejo, Antonio; Nicolás, Emilio; Fernández, José Enrique

2007-08-01

This study tests the hypothesis that diffusional limitation of photosynthesis, rather than light, determines the distribution of photosynthetic capacity in olive leaves under drought conditions. The crowns of four olive trees growing in an orchard were divided into two sectors: one sector absorbed most of the radiation early in the morning (MS) while the other absorbed most in the afternoon (AS). When the peak of radiation absorption was higher in MS, air vapour pressure deficit (VPD) was not high enough to provoke stomatal closure. In contrast, peak radiation absorption in AS coincided with the daily peak in VPD. In addition, two soil water treatments were evaluated: irrigated trees (I) and non-irrigated trees (nI). The seasonal evolution of leaf water potential, leaf gas exchange and photosynthetic capacity were measured throughout the tree crowns in spring and summer. Results showed that stomatal conductance was reduced in nI trees in summer as a consequence of soil water stress, which limited their net assimilation rate. Olive leaves displayed isohydric behaviour and no important differences in the diurnal course of leaf water potentials among treatments and sectors were found. Seasonal diffusional limitation of photosynthesis was mainly increased in nI trees, especially as a result of stomatal limitation, although mesophyll conductance (g(m)) was found to decrease in summer in both treatments and sectors. A positive relationship between leaf nitrogen content with both leaf photosynthetic capacity and the daily integrated quantum flux density was found in spring, but not in summer. The relationship between photosynthetic capacity and g(m) was curvilinear. Leaf temperature also affected to g(m) with an optimum temperature at 29 degrees C. AS showed larger biochemical limitation than MS in August in both treatments. All these suggest that both diffusional limitation and the effect of leaf temperature could be involved in the seasonal reduction of photosynthetic

Assessing the adequacy of water storage infrastructure capacity under hydroclimatic variability and water demands in the United States

Science.gov (United States)

Ho, M. W.; Devineni, N.; Cook, E. R.; Lall, U.

2017-12-01

As populations and associated economic activity in the US evolve, regional demands for water likewise change. For regions dependent on surface water, dams and reservoirs are critical to storing and managing releases of water and regulating the temporal and spatial availability of water in order to meet these demands. Storage capacities typically range from seasonal storage in the east to multi-annual and decadal-scale storage in the drier west. However, most dams in the US were designed with limited knowledge regarding the range, frequency, and persistence of hydroclimatic extremes. Demands for water supplied by these dams have likewise changed. Furthermore, many dams in the US are now reaching or have already exceeded their economic design life. The converging issues of aging dams, improved knowledge of hydroclimatic variability, and evolving demands for dam services result in a pressing need to evaluate existing reservoir capacities with respect to contemporary water demands, long term hydroclimatic variability, and service reliability into the future. Such an effort is possible given the recent development of two datasets that respectively address hydroclimatic variability in the conterminous United States over the past 555 years and human water demand related water stress over the same region. The first data set is a paleoclimate reconstruction of streamflow variability across the CONUS region based on a tree-ring informed reconstruction of the Palmer Drought Severity Index. This streamflow reconstruction suggested that wet spells with shorter drier spells were a key feature of 20th century streamflow compared with the preceding 450 years. The second data set in an annual cumulative drought index that is a measure of water balance based on water supplied through precipitation and water demands based on evaporative demands, agricultural, urban, and industrial demands. This index identified urban and regional hotspots that were particularly dependent on water

A practical approach for calculating the settlement and storage capacity of landfills based on the space and time discretization of the landfilling process.

Science.gov (United States)

Gao, Wu; Xu, Wenjie; Bian, Xuecheng; Chen, Yunmin

2017-11-01

The settlement of any position of the municipal solid waste (MSW) body during the landfilling process and after its closure has effects on the integrity of the internal structure and storage capacity of the landfill. This paper proposes a practical approach for calculating the settlement and storage capacity of landfills based on the space and time discretization of the landfilling process. The MSW body in the landfill was divided into independent column units, and the filling process of each column unit was determined by a simplified complete landfilling process. The settlement of a position in the landfill was calculated with the compression of each MSW layer in every column unit. Then, the simultaneous settlement of all the column units was integrated to obtain the settlement of the landfill and storage capacity of all the column units; this allowed to obtain the storage capacity of the landfill based on the layer-wise summation method. When the compression of each MSW layer was calculated, the effects of the fluctuation of the main leachate level and variation in the unit weight of the MSW on the overburdened effective stress were taken into consideration by introducing the main leachate level's proportion and the unit weight and buried depth curve. This approach is especially significant for MSW with a high kitchen waste content and landfills in developing countries. The stress-biodegradation compression model was used to calculate the compression of each MSW layer. A software program, Settlement and Storage Capacity Calculation System for Landfills, was developed by integrating the space and time discretization of the landfilling process and the settlement and storage capacity algorithms. The landfilling process of the phase IV of Shanghai Laogang Landfill was simulated using this software. The maximum geometric volume of the landfill error between the calculated and measured values is only 2.02%, and the accumulated filling weight error between the

First-principles investigation of hydrogen storage capacity of Y-decorated porous graphene

Energy Technology Data Exchange (ETDEWEB)

Yuan, Lihua, E-mail: yuanlh@lut.cn [State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); School of Sciences, Lanzhou University of Technology, Lanzhou 730050 (China); Chen, Yuhong, E-mail: chenyh@lut.cn [State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); School of Sciences, Lanzhou University of Technology, Lanzhou 730050 (China); Kang, Long [State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); Zhang, Cairong [State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China); School of Sciences, Lanzhou University of Technology, Lanzhou 730050 (China); Wang, Daobin; Wang, Chunni [School of Sciences, Lanzhou University of Technology, Lanzhou 730050 (China); Zhang, Meiling [School of Sciences, Lanzhou University of Technology, Lanzhou 730050 (China); School of Nuclear Science and Technology, Lanzhou university, 73000 (China); Wu, Xiaojuan [State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals, Lanzhou University of Technology, Lanzhou 730050 (China)

2017-03-31

Highlights: • The bridge of C–C bond is favorable site for a Y atom on the single side of PG and six H{sub 2} can be absorbed around it. • Two Y atoms can be stably adsorbed on the same side of one unit cell of PG, but there isn’t sufficient space for H{sub 2} absorbing around each Y atom. • The maximum number of absorbed Y atoms is two for double side of PG unit cell. • Fourteen H{sub 2} can be absorbed on the both sides of PG, and the hydrogen storage capacity is 7.87 wt.%. - Abstract: Based on first-principles method, the electron structure of porous graphene (PG) and adsorption ability of H{sub 2} molecular on Y-decorated porous graphene are investigated using CASTEP code. It is found that the bridge of C–C bond which connects two C hexagons is favorable site for a Y atom adsorbed on the single side of PG, and six H{sub 2} molecules can be absorbed around a Y atom with average adsorption energy of −0.297 eV/H{sub 2} computed by GGA-PBE functional. Though two Y atoms can be stably adsorbed on the same side of one unit cell of PG, there isn’t sufficient space for H{sub 2} absorbing around each Y atom. To improve capability of hydrogen storage, the unit cell of PG with single side should only contain one Y atom. For the case of double side of porous graphene, two Y atoms are preferably located above the center of the different C hexagon. Fourteen H{sub 2} molecules can be absorbed on both sides of PG, and the gravimetric hydrogen storage capacity is 7.87 wt.% with the average adsorption energy of −0.23 eV/H{sub 2}.

Dynamic sizing of energy storage for hedging wind power forecast uncertainty

DEFF Research Database (Denmark)

Pinson, Pierre; Papefthymiou, George; Klöckl, Bernd

2009-01-01

In market conditions where program responsible parties are penalized for deviations from proposed bids, energy storage can be used for compensating the energy imbalances induced by limited predictability of wind power. The energy storage capacity necessary for performing this task will differ bet...

Optimal Power Flow in Microgrids with Energy Storage

DEFF Research Database (Denmark)

Levron, Yoash; Guerrero, Josep M.; Beck, Yuval

2013-01-01

Energy storage may improve power management in microgrids that include renewable energy sources. The storage devices match energy generation to consumption, facilitating a smooth and robust energy balance within the microgrid. This paper addresses the optimal control of the microgrid’s energy...... storage devices. Stored energy is controlled to balance power generation of renewable sources to optimize overall power consumption at the microgrid point of common coupling. Recent works emphasize constraints imposed by the storage device itself, such as limited capacity and internal losses. However...

Capacity Prediction Model Based on Limited Priority Gap-Acceptance Theory at Multilane Roundabouts

Directory of Open Access Journals (Sweden)

Zhaowei Qu

2014-01-01

Full Text Available Capacity is an important design parameter for roundabouts, and it is the premise of computing their delay and queue. Roundabout capacity has been studied for decades, and empirical regression model and gap-acceptance model are the two main methods to predict it. Based on gap-acceptance theory, by considering the effect of limited priority, especially the relationship between limited priority factor and critical gap, a modified model was built to predict the roundabout capacity. We then compare the results between Raff’s method and maximum likelihood estimation (MLE method, and the MLE method was used to predict the critical gaps. Finally, the predicted capacities from different models were compared, with the observed capacity by field surveys, which verifies the performance of the proposed model.

Enriching the hydrogen storage capacity of carbon nanotube doped with polylithiated molecules

Science.gov (United States)

Panigrahi, P.; Naqvi, S. R.; Hankel, M.; Ahuja, R.; Hussain, T.

2018-06-01

In a quest to find optimum materials for efficient storage of clean energy, we have performed first principles calculations to study the structural and energy storage properties of one-dimensional carbon nanotubes (CNTs) functionalized with polylithiated molecules (PLMs). Van der Waals corrected calculations disclosed that various PLMs like CLi, CLi2, CLi3, OLi, OLi2, OLi3, bind strongly to CNTs even at high doping concentrations ensuring a uniform distribution of dopants without forming clusters. Bader charge analysis reveals that each Li in all the PLMs attains a partial positive charge and transform into Li+ cations. This situation allows multiple H2 molecules adsorbed with each Li+ through the polarization of incident H2 molecules via electrostatic and van der Waals type of interaction. With a maximum doping concentration, that is 3CLi2/3CLi3 and 3OLi2/3OLi3 a maximum of 36 H2 molecules could be adsorbed that corresponds to a reasonably high H2 storage capacity with the adsorption energies in the range of -0.33 to -0.15 eV/H2. This suits the ambient condition applications.

Fuel Assemblies Thermal Analysis in the New Spent Fuel Storage Facility at Inshass Site

International Nuclear Information System (INIS)

Khattab, M.; Mariy, Ahmed

1999-01-01

New Wet Storage Facility (NSF) is constructed at Inshass site to solve the problem of spent fuel storage capacity of ETRR-1 reactor . The Engineering Safety Heat Transfer Features t hat characterize the new facility are presented. Thermal analysis including different scenarios of pool heat load and safety limits are discussed . Cladding temperature limit during handling and storage process are specified for safe transfer of fuel

Significance of the Capacity Recovery Effect in Pouch Lithium-Sulfur Battery Cells

DEFF Research Database (Denmark)

Knap, Vaclav; Zhang, Teng; Stroe, Daniel Loan

2016-01-01

Lithium-Sulfur (Li-S) batteries are an emerging energy storage technology, which is technically-attractive due to its high theoretical limits; practically, it is expected that Li-S batteries will result into lighter energy storage devices with higher capacities than traditional Lithium-ion...... batteries. One of the actual disadvantages for this technology is the highly pronounced rate capacity effect, which reduces the available capacity to be discharged when high currents are used. This drawback might be addressed by the use of the capacity recovery effect, which by introducing relaxation...... periods between consecutive pulse discharges of the battery, increases the available discharge capacity of the cell. The capacity recovery effect of the Li-S cell is studied in this paper using the pulse discharge technique, considering its dependence on the applied current, discharge step length...

A consistent approach to CO{sub 2} storage capacity estimation for deep saline formations

Energy Technology Data Exchange (ETDEWEB)

Dose, T. [DEA Mineraloel AG, Hamburg (Germany)

2008-10-23

Whereas the methodology of assessing pore volume is well established, a consistent methodology for calculating the pore volume efficiency (PVE) needs to be applied, e.g., as proposed in this paper. (1) Numerical simulations show, that CO{sub 2} storage sites are not restricted to geologic traps like anticlines. Also synclines and flat structures provide feasible storage structures, as long as no shortcut to the surface like leaking faults or wells exist. (2) Among active forces induced by CO{sub 2} injection, differential injection pressure and static pressure increase may turn out to be critical. This can lead to overlap with capillary displacement pressure, fracturing pressure, and exceeding the fault friction limit. (3) If differential injection pressure turns out to be critical, this can be balanced technically. Fault slippage can be avoided by selecting appropriate sites. (4) For the CO{sub 2} storage system to stay in balance, it is required that the static pressure increase stays below the capillary displacement pressure. (5) With this limiting conditions, scenarios show PVEs of 0.1-0.65% for a hydraulic system, mostly dependant on caprock quality and total compressibility. (6) Likely several possible storage sites exist for a hydraulic system. It is almost sure that the sum of the local storage potential will exceed the storage potential of the hydraulic system. (7) Regional pressure effects of CO{sub 2} storage can be significant. Different storage sites injecting at high rates into the same hydraulic system will need large distances between them. (9) Due to likely interference of storage sites and other fluid operations within a hydraulic system, close cooperations between operators may become necessary. (orig.)

A complete NUHOMS {sup registered} solution for storage and transport of high burnup spent fuel

Energy Technology Data Exchange (ETDEWEB)

Bondre, J. [Transnuclear, Inc. (AREVA Group), Fremont, CA (United States)

2004-07-01

The discharge burnups of spent fuel from nuclear power plants keep increasing with plants discharging or planning to discharge fuel with burnups in excess of 60,000 MWD/MTU. Due to limited capacity of spent fuel pools, transfer of older cooler spent fuel from fuel pool to dry storage, and very limited options for transport of spent fuel, there is a critical need for dry storage of high burnup, higher heat load spent fuel so that plants could maintain their full core offload reserve capability. A typical NUHOMS {sup registered} solution for dry spent fuel storage is shown in the Figure 1. Transnuclear, Inc. offers two advanced NUHOMS {sup registered} solutions for the storage and transportation of high burnup fuel. One includes the NUHOMS {sup registered} 24PTH system for plants with 90.7 Metric Ton (MT) crane capacity; the other offers the higher capacity NUHOMS {sup registered} 32PTH system for higher crane capacity. These systems include NUHOMS {sup registered} - 24PTH and -32PTH Transportable Canisters stored in a concrete storage overpack (HSM-H). These canisters are designed to meet all the requirements of both storage and transport regulations. They are designed to be transported off-site either directly from the spent fuel pool or from the storage overpack in a suitable transport cask.

A Bayesian hierarchical model for the measurement of working memory capacity

NARCIS (Netherlands)

Morey, Richard D.

Working memory is the memory system that allows for conscious storage and manipulation of information. The capacity of working memory is extremely limited. Measurements of this limit, and what affects it, are critical to understanding working memory. Cowan (2001) and Pashler (1988) suggested

Capacity limits introduced by data fusion on cooperative spectrum sensing under correlated environments

DEFF Research Database (Denmark)

Pratas, Nuno; Marchetti, Nicola; Rodrigues, Antonio

2010-01-01

spectrum sensing scheme, by measuring the perceived capacity limits introduced by the use of data fusion on cooperative sensing schemes. The analysis is supported by evaluation metrics which account for the perceived capacity limits. The analysis is performed along the data fusion chain, comparing several...... scenarios encompassing different degree of environment correlation between the cluster nodes, number of cluster nodes and sensed channel occupation statistics. Through this study we motivate that to maximize the perceived capacity by the cooperative spectrum sensing, the use of data fusion needs...

Redox Flow Batteries, Hydrogen and Distributed Storage.

Science.gov (United States)

Dennison, C R; Vrubel, Heron; Amstutz, Véronique; Peljo, Pekka; Toghill, Kathryn E; Girault, Hubert H

2015-01-01

Social, economic, and political pressures are causing a shift in the global energy mix, with a preference toward renewable energy sources. In order to realize widespread implementation of these resources, large-scale storage of renewable energy is needed. Among the proposed energy storage technologies, redox flow batteries offer many unique advantages. The primary limitation of these systems, however, is their limited energy density which necessitates very large installations. In order to enhance the energy storage capacity of these systems, we have developed a unique dual-circuit architecture which enables two levels of energy storage; first in the conventional electrolyte, and then through the formation of hydrogen. Moreover, we have begun a pilot-scale demonstration project to investigate the scalability and technical readiness of this approach. This combination of conventional energy storage and hydrogen production is well aligned with the current trajectory of modern energy and mobility infrastructure. The combination of these two means of energy storage enables the possibility of an energy economy dominated by renewable resources.

Effects of storage and cooking on the antioxidant capacity of laying hen eggs.

Science.gov (United States)

Nimalaratne, Chamila; Schieber, Andreas; Wu, Jianping

2016-03-01

The aromatic amino acids and carotenoids are the major contributors to the antioxidant properties of egg yolk. This study aimed to evaluate the effect of simulated retail storage and domestic cooking on the antioxidant activity as well as on the aromatic amino acid and carotenoid contents in ordinary table eggs, omega 3/lutein (n-3/lutein) enriched eggs, and eggs from heritage chicken breeds. The oxygen radical scavenging capacity (ORAC) was the highest in n-3/lutein enriched eggs (161.4μmolTE/gsample), while eggs from heritage white leghorns (HW) showed the lowest levels (127.6μmolTE/gsample). Six weeks of storage at refrigerated temperature did not change the ORAC values, as well as the contents of free amino acid, carotenoid, and malondialdehyde (MDA) in egg yolk. Boiling and frying however, significantly reduced the ORAC value, and the contents of free amino acid, lutein and zeaxanthin, and increased the MDA content in eggs. Our results showed that the antioxidant activity is stable during six weeks of simulated retail storage. Copyright © 2015 Elsevier Ltd. All rights reserved.

Theoretical maximal storage of hydrogen in zeolitic frameworks.

Science.gov (United States)

Vitillo, Jenny G; Ricchiardi, Gabriele; Spoto, Giuseppe; Zecchina, Adriano

2005-12-07

Physisorption and encapsulation of molecular hydrogen in tailored microporous materials are two of the options for hydrogen storage. Among these materials, zeolites have been widely investigated. In these materials, the attained storage capacities vary widely with structure and composition, leading to the expectation that materials with improved binding sites, together with lighter frameworks, may represent efficient storage materials. In this work, we address the problem of the determination of the maximum amount of molecular hydrogen which could, in principle, be stored in a given zeolitic framework, as limited by the size, structure and flexibility of its pore system. To this end, the progressive filling with H2 of 12 purely siliceous models of common zeolite frameworks has been simulated by means of classical molecular mechanics. By monitoring the variation of cell parameters upon progressive filling of the pores, conclusions are drawn regarding the maximum storage capacity of each framework and, more generally, on framework flexibility. The flexible non-pentasils RHO, FAU, KFI, LTA and CHA display the highest maximal capacities, ranging between 2.86-2.65 mass%, well below the targets set for automotive applications but still in an interesting range. The predicted maximal storage capacities correlate well with experimental results obtained at low temperature. The technique is easily extendable to any other microporous structure, and it can provide a method for the screening of hypothetical new materials for hydrogen storage applications.

A solar receiver-storage modular cascade based on porous ceramic structures for hybrid sensible/thermochemical solar energy storage

Science.gov (United States)

Agrafiotis, Christos; de Oliveira, Lamark; Roeb, Martin; Sattler, Christian

2016-05-01

The current state-of-the-art solar heat storage concept in air-operated Solar Tower Power Plants is to store the solar energy provided during on-sun operation as sensible heat in porous solid materials that operate as recuperators during off-sun operation. The technology is operationally simple; however its storage capacity is limited to 1.5 hours. An idea for extending this capacity is to render this storage concept from "purely" sensible to "hybrid" sensible/ thermochemical one, via coating the porous heat exchange modules with oxides of multivalent metals for which their reduction/oxidation reactions are accompanied by significant heat effects, or by manufacturing them entirely of such oxides. In this way solar heat produced during on-sun operation can be used (in addition to sensibly heating the porous solid) to power the endothermic reduction of the oxide from its state with the higher metal valence to that of the lower; the thermal energy can be entirely recovered by the reverse exothermic oxidation reaction (in addition to sensible heat) during off-sun operation. Such sensible and thermochemical storage concepts were tested on a solar-irradiated receiver- heat storage module cascade for the first time. Parametric studies performed so far involved the comparison of three different SiC-based receivers with respect to their capability of supplying solar-heated air at temperatures sufficient for the reduction of the oxides, the effect of air flow rate on the temperatures achieved within the storage module, as well as the comparison of different porous storage media made of cordierite with respect to their sensible storage capacity.

Dynamical Origin of the Effective Storage Capacity in the Brain's Working Memory

Science.gov (United States)

Bick, Christian; Rabinovich, Mikhail I.

2009-11-01

The capacity of working memory (WM), a short-term buffer for information in the brain, is limited. We suggest a model for sequential WM that is based upon winnerless competition amongst representations of available informational items. Analytical results for the underlying mathematical model relate WM capacity and relative lateral inhibition in the corresponding neural network. This implies an upper bound for WM capacity, which is, under reasonable neurobiological assumptions, close to the “magical number seven.”

Genetic algorithm for chromaticity correction in diffraction limited storage rings

Directory of Open Access Journals (Sweden)

M. P. Ehrlichman

2016-04-01

Full Text Available A multiobjective genetic algorithm is developed for optimizing nonlinearities in diffraction limited storage rings. This algorithm determines sextupole and octupole strengths for chromaticity correction that deliver optimized dynamic aperture and beam lifetime. The algorithm makes use of dominance constraints to breed desirable properties into the early generations. The momentum aperture is optimized indirectly by constraining the chromatic tune footprint and optimizing the off-energy dynamic aperture. The result is an effective and computationally efficient technique for correcting chromaticity in a storage ring while maintaining optimal dynamic aperture and beam lifetime.

From Fundamental Understanding To Predicting New Nanomaterials For High Capacity Hydrogen/Methane Storage and Carbon Capture

Energy Technology Data Exchange (ETDEWEB)

Yildirim, Taner [Univ. of Pennsylvania, Philadelphia, PA (United States)

2015-03-03

On-board hydrogen/methane storage in fuel cell-powered vehicles is a major component of the national need to achieve energy independence and protect the environment. The main obstacles in hydrogen storage are slow kinetics, poor reversibility and high dehydrogenation temperatures for the chemical hydrides; and very low desorption temperatures/energies for the physisorption materials (MOF’s, porous carbons). Similarly, the current methane storage technologies are mainly based on physisorption in porous materials but the gravimetric and volumetric storage capacities are below the target values. Finally, carbon capture, a critical component of the mitigation of CO2 emissions from industrial plants, also suffers from similar problems. The solid-absorbers such as MOFs are either not stable against real flue-gas conditions and/or do not have large enough CO2 capture capacity to be practical and cost effective. In this project, we addressed these challenges using a unique combination of computational, synthetic and experimental methods. The main scope of our research was to achieve fundamental understanding of the chemical and structural interactions governing the storage and release of hydrogen/methane and carbon capture in a wide spectrum of candidate materials. We studied the effect of scaffolding and doping of the candidate materials on their storage and dynamics properties. We reviewed current progress, challenges and prospect in closely related fields of hydrogen/methane storage and carbon capture.[1-5] For example, for physisorption based storage materials, we show that tap-densities or simply pressing MOFs into pellet forms reduce the uptake capacities by half and therefore packing MOFs is one of the most important challenges going forward. For room temperature hydrogen storage application of MOFs, we argue that MOFs are the most promising scaffold materials for Ammonia-Borane (AB) because of their unique interior active metal-centers for AB binding and well

Spent fuel storage requirements

International Nuclear Information System (INIS)

Fletcher, J.

1982-06-01

Spent fuel storage requirements, as projected through the year 2000 for U.S. LWRs, were calculated using information supplied by the utilities reflecting plant status as of December 31, 1981. Projections through the year 2000 combined fuel discharge projections of the utilities with the assumed discharges of typical reactors required to meet the nuclear capacity of 165 GWe projected by the Energy Information Administration (EIA) for the year 2000. Three cases were developed and are summarized. A reference case, or maximum at-reactor (AR) capacity case, assumes that all reactor storage pools are increased to their maximum capacities as estimated by the utilities for spent fuel storage utilizing currently licensed technologies. The reference case assumes no transshipments between pools except as currently licensed by the Nuclear Regulatory Commission (NRC). This case identifies an initial requirement for 13 MTU of additional storage in 1984, and a cumulative requirement for 14,490 MTU additional storage in the year 2000. The reference case is bounded by two alternative cases. One, a current capacity case, assumes that only those pool storage capacity increases currently planned by the operating utilities will occur. The second, or maximum capacity with transshipment case, assumes maximum development of pool storage capacity as described above and also assumes no constraints on transshipment of spent fuel among pools of reactors of like type (BWR, PWR) within a given utility. In all cases, a full core discharge capability (full core reserve or FCR) is assumed to be maintained for each reactor, except that only one FCR is maintained when two reactors share a common pool. For the current AR capacity case the indicated storage requirements in the year 2000 are indicated to be 18,190 MTU; for the maximum capacity with transshipment case they are 11,320 MTU

Adsorptive storage of natural gas

International Nuclear Information System (INIS)

Yan, Song; Lang, Liu; Licheng, Ling

2001-01-01

The Adsorbed Natural Gas (ANG) storage technology is reviewed. The present status, theoretical limits and operational problems are discussed. Natural gas (NG) has a considerable advantage over conventional fuels both from an environmental point of view and for its natural abundance. However, as well known, it has a two fold disadvantage compared with liquid fuels: it is relatively expensive to transport from the remote areas, and its energy density (heat of combustion/volume) is low. All these will restrict its use. Compressed natural gas (CNG) may be a solution, but high pressures are needed (up to 25 MPa) for use in natural-gas fueled vehicles, and the large cost of the cylinders for storage and the high-pressure facilities necessary limit the practical use of CNG. Alternatively, adsorbed natural gas (ANG) at 3 - 4 MPa offers a very high potential for exploitation in both transport and large-scale applications. At present, research about this technology mainly focuses on: to make adsorbents with high methane adsorption capacity; to make clear the effects of heat of adsorption and the effect of impurities in natural gas on adsorption and desorption capacity. This paper provides an overview of current technology and examines the relations between fundamentals of adsorption and ANG storage. (authors)

The H_6_0Si_6C_5_4 heterofullerene as high-capacity hydrogen storage medium

International Nuclear Information System (INIS)

Yong, Yongliang; Zhou, Qingxiao; Li, Xiaohong; Lv, Shijie

2016-01-01

With the great success in Si atoms doped C_6_0 fullerene and the well-established methods for synthesis of hydrogenated carbon fullerenes, this leads naturally to wonder whether Si-doped fullerenes are possible for special applications such as hydrogen storage. Here by using first-principles calculations, we design a novel high-capacity hydrogen storage material, H_6_0Si_6C_5_4 heterofullerene, and confirm its geometric stability. It is found that the H_6_0Si_6C_5_4 heterofullerene has a large HOMO-LUMO gap and a high symmetry, indicating it is high chemically stable. Further, our finite temperature simulations indicate that the H_6_0Si_6C_5_4 heterofullerene is thermally stable at 300 K. H_2 molecules would enter into the cage from the Si-hexagon ring because of lower energy barrier. Through our calculation, a maximum of 21 H_2 molecules can be stored inside the H_6_0Si_6C_5_4 cage in molecular form, leading to a gravimetric density of 11.11 wt% for 21H_2@H_6_0Si_6C_5_4 system, which suggests that the hydrogenated Si_6C_5_4 heterofullerene could be suitable as a high-capacity hydrogen storage material.

Higher-capacity lithium ion battery chemistries for improved residential energy storage with micro-cogeneration

International Nuclear Information System (INIS)

Darcovich, K.; Henquin, E.R.; Kenney, B.; Davidson, I.J.; Saldanha, N.; Beausoleil-Morrison, I.

2013-01-01

Highlights: • Characterized two novel high capacity electrode materials for Li-ion batteries. • A numerical discharge model was run to characterize Li-ion cell behavior. • Engineering model of Li-ion battery pack developed from cell fundamentals. • ESP-r model integrated micro-cogeneration and high capacity Li-ion storage. • Higher capacity batteries shown to improve micro-cogeneration systems. - Abstract: Combined heat and power on a residential scale, also known as micro-cogeneration, is currently gaining traction as an energy savings practice. The configuration of micro-cogeneration systems is highly variable, as local climate, energy supply, energy market and the feasibility of including renewable type components such as wind turbines or photovoltaic panels are all factors. Large-scale lithium ion batteries for electrical storage in this context can provide cost savings, operational flexibility, and reduced stress on the distribution grid as well as a degree of contingency for installations relying upon unsteady renewables. Concurrently, significant advances in component materials used to make lithium ion cells offer performance improvements in terms of power output, energy capacity, robustness and longevity, thereby enhancing their prospective utility in residential micro-cogeneration installations. The present study evaluates annual residential energy use for a typical Canadian home connected to the electrical grid, equipped with a micro-cogeneration system consisting of a Stirling engine for supplying heat and power, coupled with a nominal 2 kW/6 kW h lithium ion battery. Two novel battery cathode chemistries, one a new Li–NCA material, the other a high voltage Ni-doped lithium manganate, are compared in the residential micro-cogeneration context with a system equipped with the presently conventional LiMn 2 O 4 spinel-type battery

Integrated project for increasing the capacity of spent fuel pools at Cofrentes NPP

International Nuclear Information System (INIS)

Rebollo Garcia, C.; Arana, S.

1996-01-01

The current storage capacity of the Cofrentes NPP will have reached its limit by the end of its 15th cycle, in the year 2005. The works performed by Empresarios Agrupados for IBERDROLA show that it is possible to increase this capacity in successive phases, so as to make the Power Plant self-sufficient for 16 more years (up to 2021) in the case of compact storage, or for 50 more years (2055) in the case of consolidated storage or second level storage. Optimisation of the management of high-activity wastes goes with a series of tasks which come under the group referred to as Integrated Project for Increasing the Capacity of Spent Fuel Pools. The main activities of the project can be summarised under the following three items: increase of storage capacity (feasibility study, specification for the purchase of racks, manufacture, assembly and tests), improvement of the capacity of the pool cooling system and modification of the components and accessories located inside the pools which interfere with the new racks. Another series of activities with less technical and economic impact are: modification of fuel handling machines, management of generated radwaste, licensing and modification of plant documentation (seismic analysis, radiation areas, as-built drawings and verification of the validation of purification and HVAC systems). (Author)

The next generation mass storage devices - Physical principles and current status

Science.gov (United States)

Wang, L.; Gai, S.

2014-04-01

The amount of digital data today has been increasing at a phenomenal rate due to the widespread digitalisation service in almost every industry. The need to store such ever-increasing data aggressively triggers the requirement to augment the storage capacity of the conventional storage technologies. Unfortunately, the physical limitations that conventional forms face have severely handicapped their potential to meet the storage need from both consumer and industry point of view. The focus has therefore been switched into the development of the innovative data storage technologies such as scanning probe memory, nanocrystal memory, carbon nanotube memory, DNA memory, and organic memory. In this paper, we review the physical principles of these emerging storage technologies and their superiorities as the next generation data storage device, as well as their respective technical challenges on further enhancing the storage capacity. We also compare these novel technologies with the mainstream data storage means according to the technology roadmap on areal density.

Increased charge storage capacity of titanium nitride electrodes by deposition of boron-doped nanocrystalline diamond films

DEFF Research Database (Denmark)

Meijs, Suzan; McDonald, Matthew; Sørensen, Søren

2015-01-01

The aim of this study was to investigate the feasibility of depositing a thin layer of boron-doped nanocrystalline diamond (B-NCD) on titanium nitride (TiN) coated electrodes and the effect this has on charge injection properties. The charge storage capacity increased by applying the B-NCD film...

Optimal Capacity Estimation Method of the Energy Storage Mounted on a Wireless Railway Train for Energy-Sustainable Transportation

Directory of Open Access Journals (Sweden)

Jaewon Kim

2018-04-01

Full Text Available Although electric railway systems have gone through many technological innovations in their electrical, mechanical and structural engineering since the energy paradigm conversion to electrical energy, the conventional feeding system based on the catenary contact is still being applied. In order to solve the problems of the contact-based feeding system that arise and to build up the energy-sustainable electric railway system simultaneously, this paper considers the wireless railway train (WRT, which is fed by storages mounted on the board without catenary contact during driving and charged at a platform during a stop. In order to maximize the energy improvement of WRTs’ operation, the optimal power and storage capacity estimation method considering the increased weight of the additional storage devices is proposed. Through case studies of the electrical and topographical conditions of the actual operating railway route, compared with the electrical performance of the existing railway trains, it is verified that the application of WRTs leads to facility capacity margin enlargement through the peak power reduction, and cost-effectiveness improvement through the reduction of catenary loss and driving energy.

Economic performance of irrigation capacity development to adapt to climate in the American Southwest

Science.gov (United States)

Ward, Frank A.; Crawford, Terry L.

2016-09-01

additional storage, removal of constraints on weak transportation capacity, limited production scale, poor information access, weak risk-bearing capacity, limited management skills, scarce labor supply, low food processing capacity, and absolute scale constraints, all can raise the economic value of additional irrigation capacity development. Our results light a path forward to policy makers, water administrators, and farm managers, who bear the burden of protecting farm income, food and water security, and rural economic development in the world's dry regions faced by the need to adapt to climate variability.

DISCHARGE OXIDE STORAGE CAPACITY AND VOLTAGE LOSS IN LI-AIR BATTERY

International Nuclear Information System (INIS)

Wang, Yun; Wang, Zhe; Yuan, Hao; Li, Tianqi

2015-01-01

Air cathodes, where oxygen reacts with Li ions and electrons with discharge oxide stored in their pore structure, are often considered as the most challenging component in nonaqueous Lithium-air batteries. In non-aqueous electrolytes, discharge oxides are usually insoluble and hence precipitate at local reaction site, raising the oxygen transport resistance in the pore network. Due to their low electric conductivity, their presence causes electrode passivation. This study aims to investigate the air cathode’s performance through analytically obtaining oxygen profiles, modeling electrode passivation, evaluating the transport polarization raised by discharge oxide precipitate, and developing analytical formulas for insoluble Li oxides storage capacity. The variations of cathode quantities, including oxygen content and temperature, are evaluated and related to a single dimensionless parameter — the Damköhler Number (Da). An approximate model is developed to predict discharge voltage loss, along with validation against two sets of experimental data. Air cathode properties, including tortuosity, surface coverage factor and the Da number, and their effects on the cathode’s capacity of storing Li oxides are formulated and discussed.

Limitations of Human Visual Working Memory

OpenAIRE

Wesenick, Maria-Barbara

2004-01-01

The present empirical study investigates limitations of human visual working memory (VWM). The experiments of the present work involve the experimental paradigm of change detection using simple geometrical objects in the form of rectangles of different colour, length, and orientation. It can be shown, that a limited performance in the temporary storage of visual information has multiple sources. Limitations of VWM can be attributed to a limited capacity or a limited duration, but also to limi...

Capacity enhancement of aqueous borohydride fuels for hydrogen storage in liquids

Energy Technology Data Exchange (ETDEWEB)

Schubert, David [U.S. Borax Inc., Rio Tinto, CO (United States); Neiner, Doinita [U.S. Borax Inc., Rio Tinto, CO (United States); Bowden, Mark [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Whittemore, Sean [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Holladay, Jamie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Huang, Zhenguo [Univ. of Wollongong, NSW (Australia); Autrey, Tom [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-10-01

In this work we demonstrate enhanced hydrogen storage capacities through increased solubility of sodium borate product species in aqueous media achieved by adjusting the sodium (NaOH) to boron (B(OH)₃) ratio, i.e., M/B, to obtain a distribution of polyborate anions. For a 1:1 mole ratio of NaOH to B(OH)₃, M/B = 1, the ratio of the hydrolysis product formed from NaBH₄ hydrolysis, the sole borate species formed and observed by 11B NMR is sodium metaborate, NaB(OH)₄. When the ratio is 1:3 NaOH to B(OH)₃, M/B = 0.33, a mixture of borate anions is formed and observed as a broad peak in the 11B NMR spectrum. The complex polyborate mixture yields a metastable solution that is difficult to crystallize. Given the enhanced solubility of the polyborate mixture formed when M/B = 0.33 it should follow that the hydrolysis of sodium octahydrotriborate, NaB₃H₈, can provide a greater storage capacity of hydrogen for fuel cell applications compared to sodium borohydride while maintaining a single phase. Accordingly, the hydrolysis of a 23 wt% NaB₃H₈ solution in water yields a solution having the same complex polyborate mixture as formed by mixing a 1:3 molar ratio of NaOH and B(OH)₃ and releases >8 eq of H₂. By optimizing the M/B ratio a complex mixture of soluble products, including B₃O₃(OH)₅^2-, B₄O₅(OH)₄^2-, B₃O₃(OH)^4-, B₅O₆(OH)^4- and B(OH)₃, can be maintained as a single liquid phase throughout the hydrogen release process. Consequently, hydrolysis of NaB₃H₈ can provide a 40% increase in H₂ storage density compared to the hydrolysis of NaBH₄ given the decreased solubility of sodium metaborate. The authors would like to thank Jim Sisco and Paul Osenar of

Graphene oxide/metal nanocrystal multilaminates as the atomic limit for safe and selective hydrogen storage.

Science.gov (United States)

Cho, Eun Seon; Ruminski, Anne M; Aloni, Shaul; Liu, Yi-Sheng; Guo, Jinghua; Urban, Jeffrey J

2016-02-23

Interest in hydrogen fuel is growing for automotive applications; however, safe, dense, solid-state hydrogen storage remains a formidable scientific challenge. Metal hydrides offer ample storage capacity and do not require cryogens or exceedingly high pressures for operation. However, hydrides have largely been abandoned because of oxidative instability and sluggish kinetics. We report a new, environmentally stable hydrogen storage material constructed of Mg nanocrystals encapsulated by atomically thin and gas-selective reduced graphene oxide (rGO) sheets. This material, protected from oxygen and moisture by the rGO layers, exhibits exceptionally dense hydrogen storage (6.5 wt% and 0.105 kg H2 per litre in the total composite). As rGO is atomically thin, this approach minimizes inactive mass in the composite, while also providing a kinetic enhancement to hydrogen sorption performance. These multilaminates of rGO-Mg are able to deliver exceptionally dense hydrogen storage and provide a material platform for harnessing the attributes of sensitive nanomaterials in demanding environments.

Oxygen Storage Capacity and Oxygen Mobility of Co-Mn-Mg-Al Mixed Oxides and Their Relation in the VOC Oxidation Reaction

Directory of Open Access Journals (Sweden)

María Haidy Castaño

2015-05-01

Full Text Available Co-Mn-Mg-Al oxides were synthesized using auto-combustion and co-precipitation techniques. Constant ratios were maintained with (Co + Mn + Mg/Al equal to 3.0, (Co + Mn/Mg equal to 1.0 and Co/Mn equal to 0.5. The chemical and structural composition, redox properties, oxygen storage capacity and oxygen mobility were analyzed using X-ray fluorescence (XRF, X-ray diffraction (XRD, Raman spectroscopy, scanning electron microscopy (SEM, temperature-programmed reduction of hydrogen (H2-TPR, oxygen storage capacity (OSC, oxygen storage complete capacity (OSCC and isotopic exchange, respectively. The catalytic behavior of the oxides was evaluated in the total oxidation of a mixture of 250 ppm toluene and 250 ppm 2-propanol. The synthesis methodology affected the crystallite size, redox properties, OSC and oxide oxygen mobility, which determined the catalytic behavior. The co-precipitation method got the most active oxide in the oxidation of the volatile organic compound (VOC mixture because of the improved mobility of oxygen and ability to favor redox processes in the material structure.

Storage of platelets: effects associated with high platelet content in platelet storage containers.

Science.gov (United States)

Gulliksson, Hans; Sandgren, Per; Sjödin, Agneta; Hultenby, Kjell

2012-04-01

A major problem associated with platelet storage containers is that some platelet units show a dramatic fall in pH, especially above certain platelet contents. The aim of this study was a detailed investigation of the different in vitro effects occurring when the maximum storage capacity of a platelet container is exceeded as compared to normal storage. Buffy coats were combined in large-volume containers to create primary pools to be split into two equal aliquots for the preparation of platelets (450-520×10(9) platelets/unit) in SSP+ for 7-day storage in two containers (test and reference) with different platelet storage capacity (n=8). Exceeding the maximum storage capacity of the test platelet storage container resulted in immediate negative effects on platelet metabolism and energy supply, but also delayed effects on platelet function, activation and disintegration. Our study gives a very clear indication of the effects in different phases associated with exceeding the maximum storage capacity of platelet containers but throw little additional light on the mechanism initiating those negative effects. The problem appears to be complex and further studies in different media using different storage containers will be needed to understand the mechanisms involved.

Analysis of Paralleling Limited Capacity Voltage Sources by Projective Geometry Method

Directory of Open Access Journals (Sweden)

Alexandr Penin

2014-01-01

Full Text Available The droop current-sharing method for voltage sources of a limited capacity is considered. Influence of equalizing resistors and load resistor is investigated on uniform distribution of relative values of currents when the actual loading corresponds to the capacity of a concrete source. Novel concepts for quantitative representation of operating regimes of sources are entered with use of projective geometry method.

Hydrogen Storage Materials for Mobile and Stationary Applications: Current State of the Art.

Science.gov (United States)

Lai, Qiwen; Paskevicius, Mark; Sheppard, Drew A; Buckley, Craig E; Thornton, Aaron W; Hill, Matthew R; Gu, Qinfen; Mao, Jianfeng; Huang, Zhenguo; Liu, Hua Kun; Guo, Zaiping; Banerjee, Amitava; Chakraborty, Sudip; Ahuja, Rajeev; Aguey-Zinsou, Kondo-Francois

2015-09-07

One of the limitations to the widespread use of hydrogen as an energy carrier is its storage in a safe and compact form. Herein, recent developments in effective high-capacity hydrogen storage materials are reviewed, with a special emphasis on light compounds, including those based on organic porous structures, boron, nitrogen, and aluminum. These elements and their related compounds hold the promise of high, reversible, and practical hydrogen storage capacity for mobile applications, including vehicles and portable power equipment, but also for the large scale and distributed storage of energy for stationary applications. Current understanding of the fundamental principles that govern the interaction of hydrogen with these light compounds is summarized, as well as basic strategies to meet practical targets of hydrogen uptake and release. The limitation of these strategies and current understanding is also discussed and new directions proposed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of capacity limits, memory loss, and sound type in change deafness.

Science.gov (United States)

Gregg, Melissa K; Irsik, Vanessa C; Snyder, Joel S

2017-11-01

Change deafness, the inability to notice changes to auditory scenes, has the potential to provide insights about sound perception in busy situations typical of everyday life. We determined the extent to which change deafness to sounds is due to the capacity of processing multiple sounds and the loss of memory for sounds over time. We also determined whether these processing limitations work differently for varying types of sounds within a scene. Auditory scenes composed of naturalistic sounds, spectrally dynamic unrecognizable sounds, tones, and noise rhythms were presented in a change-detection task. On each trial, two scenes were presented that were same or different. We manipulated the number of sounds within each scene to measure memory capacity and the silent interval between scenes to measure memory loss. For all sounds, change detection was worse as scene size increased, demonstrating the importance of capacity limits. Change detection to the natural sounds did not deteriorate much as the interval between scenes increased up to 2,000 ms, but it did deteriorate substantially with longer intervals. For artificial sounds, in contrast, change-detection performance suffered even for very short intervals. The results suggest that change detection is generally limited by capacity, regardless of sound type, but that auditory memory is more enduring for sounds with naturalistic acoustic structures.

Extended storage of spent fuel

International Nuclear Information System (INIS)

1992-10-01

This document is the final report on the IAEA Co-ordinated Research Programme on the Behaviour of Spent Fuel and Storage Facility Components during Long Term Storage (BEFAST-II, 1986-1991). It contains the results on wet and dry spent fuel storage technologies obtained from 16 organizations representing 13 countries who participated in the co-ordinated research programme. Considerable quantities of spent fuel continue to arise and accumulate. Many countries are investigating the option of extended spent fuel storage prior to reprocessing or fuel disposal. Wet storage continues to predominate as an established technology with the construction of additional away-from-reactor storage pools. However, dry storage is increasingly used with most participants considering dry storage concepts for the longer term. Depending on the cladding type options of dry storage in air or inert gas are proposed. Dry storage is becoming widely used as a supplement to wet storage for zirconium alloy clad oxide fuels. Storage periods as long as under wet conditions appear to be feasible. Dry storage will also continue to be used for Al clad and Magnox type fuel. Enhancement of wet storage capacity will remain an important activity. Rod consolidation to increase wet storage capacity will continue in the UK and is being evaluated for LWR fuel in the USA, and may start in some other countries. High density storage racks have been successfully introduced in many existing pools and are planned for future facilities. For extremely long wet storage (≥50 years), there is a need to continue work on fuel integrity investigations and LWR fuel performance modelling. it might be that pool component performance in some cases could be more limiting than the FA storage performance. It is desirable to make concerted efforts in the field of corrosion monitoring and prediction of fuel cladding and poll component behaviour in order to maintain good experience of wet storage. Refs, figs and tabs

Environmental capacity and the limits of predictive science

International Nuclear Information System (INIS)

Taylor, P.

1991-01-01

This paper examines the failure of pollution control and hazardous waste management strategies in the light of rapid environmental degradation observed in the decade of the 1980s. It focuses upon the central role of predictive science and assimilative capacity concepts in that failure and the development, a s a consequence, of a paradigm shift in approach, utilising the principles of precautionary action with regard to all substances, programmes of clean production applied to all industrial sectors, and source reduction applied to dissipative activities giving rise to hazardous waste. The past 'assimilative capacity' approaches are criticised as an inadequate foundation for development. In particular the nuclear regulatory concepts of 'justification', 'optimisation' and 'dose-limitation' are seriously deficient. New assessment procedures under development in the London dumping convention are discussed in the light of the precautionary principle. (au)

Congestion patterns of electric vehicles with limited battery capacity

Science.gov (United States)

2018-01-01

The path choice behavior of battery electric vehicle (BEV) drivers is influenced by the lack of public charging stations, limited battery capacity, range anxiety and long battery charging time. This paper investigates the congestion/flow pattern captured by stochastic user equilibrium (SUE) traffic assignment problem in transportation networks with BEVs, where the BEV paths are restricted by their battery capacities. The BEV energy consumption is assumed to be a linear function of path length and path travel time, which addresses both path distance limit problem and road congestion effect. A mathematical programming model is proposed for the path-based SUE traffic assignment where the path cost is the sum of the corresponding link costs and a path specific out-of-energy penalty. We then apply the convergent Lagrangian dual method to transform the original problem into a concave maximization problem and develop a customized gradient projection algorithm to solve it. A column generation procedure is incorporated to generate the path set. Finally, two numerical examples are presented to demonstrate the applicability of the proposed model and the solution algorithm. PMID:29543875

Congestion patterns of electric vehicles with limited battery capacity.

Science.gov (United States)

Jing, Wentao; Ramezani, Mohsen; An, Kun; Kim, Inhi

2018-01-01

The path choice behavior of battery electric vehicle (BEV) drivers is influenced by the lack of public charging stations, limited battery capacity, range anxiety and long battery charging time. This paper investigates the congestion/flow pattern captured by stochastic user equilibrium (SUE) traffic assignment problem in transportation networks with BEVs, where the BEV paths are restricted by their battery capacities. The BEV energy consumption is assumed to be a linear function of path length and path travel time, which addresses both path distance limit problem and road congestion effect. A mathematical programming model is proposed for the path-based SUE traffic assignment where the path cost is the sum of the corresponding link costs and a path specific out-of-energy penalty. We then apply the convergent Lagrangian dual method to transform the original problem into a concave maximization problem and develop a customized gradient projection algorithm to solve it. A column generation procedure is incorporated to generate the path set. Finally, two numerical examples are presented to demonstrate the applicability of the proposed model and the solution algorithm.

The storage capacity of Potts models for semantic memory retrieval

Science.gov (United States)

Kropff, Emilio; Treves, Alessandro

2005-08-01

We introduce and analyse a minimal network model of semantic memory in the human brain. The model is a global associative memory structured as a collection of N local modules, each coding a feature, which can take S possible values, with a global sparseness a (the average fraction of features describing a concept). We show that, under optimal conditions, the number cM of modules connected on average to a module can range widely between very sparse connectivity (high dilution, c_{M}/N\\to 0 ) and full connectivity (c_{M}\\to N ), maintaining a global network storage capacity (the maximum number pc of stored and retrievable concepts) that scales like pc~cMS2/a, with logarithmic corrections consistent with the constraint that each synapse may store up to a fraction of a bit.

Effects of Scandinavian hydro power on storage needs in a fully renewable European power system for various transmission capacity scenarios

Science.gov (United States)

Kies, Alexander; Nag, Kabitri; von Bremen, Lueder; Lorenz, Elke; Heinemann, Detlev

2015-04-01

The penetration of renewable energies in the European power system has increased in the last decades (23.5% share of renewables in the gross electricity consumption of the EU-28 in 2012) and is expected to increase further up to very high shares close to 100%. Planning and organizing this European energy transition towards sustainable power sources will be one of the major challenges of the 21st century. It is very likely that in a fully renewable European power system wind and photovoltaics (pv) will contribute the largest shares to the generation mix followed by hydro power. However, feed-in from wind and pv is due to the weather dependant nature of their resources fluctuating and non-controllable. To match generation and consumption several solutions and their combinations were proposed like very high backup-capacities of conventional power generation (e.g. fossile or nuclear), storages or the extension of the transmission grid. Apart from those options hydro power can be used to counterbalance fluctuating wind and pv generation to some extent. In this work we investigate the effects of hydro power from Norway and Sweden on residual storage needs in Europe depending on the overlaying grid scenario. High temporally and spatially resolved weather data with a spatial resolution of 7 x 7 km and a temporal resolution of 1 hour was used to model the feed-in from wind and pv for 34 investigated European countries for the years 2003-2012. Inflow into hydro storages and generation by run-of-river power plants were computed from ERA-Interim reanalysis runoff data at a spatial resolution of 0.75° x 0.75° and a daily temporal resolution. Power flows in a simplified transmission grid connecting the 34 European countries were modelled minimizing dissipation using a DC-flow approximation. Previous work has shown that hydro power, namely in Norway and Sweden, can reduce storage needs in a renewable European power system by a large extent. A 15% share of hydro power in Europe

Peak reduction for commercial buildings using energy storage

Science.gov (United States)

Chua, K. H.; Lim, Y. S.; Morris, S.

2017-11-01

Battery-based energy storage has emerged as a cost-effective solution for peak reduction due to the decrement of battery’s price. In this study, a battery-based energy storage system is developed and implemented to achieve an optimal peak reduction for commercial customers with the limited energy capacity of the energy storage. The energy storage system is formed by three bi-directional power converter rated at 5 kVA and a battery bank with capacity of 64 kWh. Three control algorithms, namely fixed-threshold, adaptive-threshold, and fuzzy-based control algorithms have been developed and implemented into the energy storage system in a campus building. The control algorithms are evaluated and compared under different load conditions. The overall experimental results show that the fuzzy-based controller is the most effective algorithm among the three controllers in peak reduction. The fuzzy-based control algorithm is capable of incorporating a priori qualitative knowledge and expertise about the load characteristic of the buildings as well as the useable energy without over-discharging the batteries.

Alternatives for water basin spent fuel storage using pin storage

International Nuclear Information System (INIS)

Viebrock, J.M.; Carlson, R.W.

1979-09-01

The densest tolerable form for storing spent nuclear fuel is storage of only the fuel rods. This eliminates the space between the fuel rods and frees the hardware to be treated as non-fuel waste. The storage density can be as much as 1.07 MTU/ft 2 when racks are used that just satisfy the criticality and thermal limitations. One of the major advantages of pin storage is that it is compatible with existing racks; however, this reduces the storage density to 0.69 MTU/ft 2 . Even this is a substantial increase over the 0.39 MTU/ft 2 that is achievable with current high capacity stainless steel racks which have been selected as the bases for comparison. Disassembly requires extensive operation on the fuel assembly to remove the upper end fitting and to extract the fuel rods from the assembly skeleton. These operations will be performed with the aid of an elevator to raise the assembly where each fuel rod is grappled. Lowering the elevator will free the fuel rod for transfer to the storage canister. A storage savings of $1510 per MTU can be realized if the pin storage concept is incorporated at a new away-from-reactor facility. The storage cost ranges from $3340 to $7820 per MTU of fuel stored with the lower cost applying to storage at an existing away-from-reactor storage facility and the higher cost applying to at-reactor storage

Evaluation of limiting mechanisms for long-term spent fuel dry storage

International Nuclear Information System (INIS)

Rashid, J.; Machiels, A.

2001-01-01

Several failure mechanisms have been postulated that could become limiting for spent fuel in dry storage. These are: stress Corrosion Cracking (SCC), Delayed Hydride Cracking (DHC) and Creep Rupture (CR). These mechanisms are examined in some detail from two perspectives: their initial environments in which they were developed and applied, and in relation to their applicability to dry storage. Extrapolation techniques are used to transfer the mechanisms from their initial in-reactor and laboratory domains to out-of-reactor spent fuel dry storage environments. This transfer is accomplished both qualitatively where necessary and quantitatively when possible, with fracture toughness used as the transfer function. In this regard, the paper provides useful information on cladding fracture toughness estimates that recognize the specific physical conditions of the cladding, which would not be found elsewhere in the literature. The arguments presented in this paper confirm the general technical consensus that creep is the governing mechanism for spent fuel in long-term dry storage. (author)

Evaluation of limiting mechanisms for long-term spent fuel dry storage

Energy Technology Data Exchange (ETDEWEB)

Rashid, J. [ANATECH Research Corp., San Diego, CA (United States); Machiels, A. [EPRI, Palo Alto, CA (United States)

2001-07-01

Several failure mechanisms have been postulated that could become limiting for spent fuel in dry storage. These are: stress Corrosion Cracking (SCC), Delayed Hydride Cracking (DHC) and Creep Rupture (CR). These mechanisms are examined in some detail from two perspectives: their initial environments in which they were developed and applied, and in relation to their applicability to dry storage. Extrapolation techniques are used to transfer the mechanisms from their initial in-reactor and laboratory domains to out-of-reactor spent fuel dry storage environments. This transfer is accomplished both qualitatively where necessary and quantitatively when possible, with fracture toughness used as the transfer function. In this regard, the paper provides useful information on cladding fracture toughness estimates that recognize the specific physical conditions of the cladding, which would not be found elsewhere in the literature. The arguments presented in this paper confirm the general technical consensus that creep is the governing mechanism for spent fuel in long-term dry storage. (author)

Analyzing the Impact of Storage Shortage on Data Availability in Decentralized Online Social Networks

Directory of Open Access Journals (Sweden)

Songling Fu

2014-01-01

Full Text Available Maintaining data availability is one of the biggest challenges in decentralized online social networks (DOSNs. The existing work often assumes that the friends of a user can always contribute to the sufficient storage capacity to store all data. However, this assumption is not always true in today’s online social networks (OSNs due to the fact that nowadays the users often use the smart mobile devices to access the OSNs. The limitation of the storage capacity in mobile devices may jeopardize the data availability. Therefore, it is desired to know the relation between the storage capacity contributed by the OSN users and the level of data availability that the OSNs can achieve. This paper addresses this issue. In this paper, the data availability model over storage capacity is established. Further, a novel method is proposed to predict the data availability on the fly. Extensive simulation experiments have been conducted to evaluate the effectiveness of the data availability model and the on-the-fly prediction.

High storage capacity in the Hopfield model with auto-interactions—stability analysis

International Nuclear Information System (INIS)

Rocchi, Jacopo; Saad, David; Tantari, Daniele

2017-01-01

Recent studies point to the potential storage of a large number of patterns in the celebrated Hopfield associative memory model, well beyond the limits obtained previously. We investigate the properties of new fixed points to discover that they exhibit instabilities for small perturbations and are therefore of limited value as associative memories. Moreover, a large deviations approach also shows that errors introduced to the original patterns induce additional errors and increased corruption with respect to the stored patterns. (paper)

High storage capacity in the Hopfield model with auto-interactions—stability analysis

Science.gov (United States)

Rocchi, Jacopo; Saad, David; Tantari, Daniele

2017-11-01

Recent studies point to the potential storage of a large number of patterns in the celebrated Hopfield associative memory model, well beyond the limits obtained previously. We investigate the properties of new fixed points to discover that they exhibit instabilities for small perturbations and are therefore of limited value as associative memories. Moreover, a large deviations approach also shows that errors introduced to the original patterns induce additional errors and increased corruption with respect to the stored patterns.

Aluminum and silicon based phase change materials for high capacity thermal energy storage

International Nuclear Information System (INIS)

Wang, Zhengyun; Wang, Hui; Li, Xiaobo; Wang, Dezhi; Zhang, Qinyong; Chen, Gang; Ren, Zhifeng

2015-01-01

Six compositions of aluminum (Al) and silicon (Si) based materials: 87.8Al-12.2Si, 80Al–20Si, 70Al–30Si, 60Al–40Si, 45Al–40Si–15Fe, and 17Al–53Si–30Ni (atomic ratio), were investigated for potentially high thermal energy storage (TES) application from medium to high temperatures (550–1200 °C) through solid–liquid phase change. Thermal properties such as melting point, latent heat, specific heat, thermal diffusivity and thermal conductivity were investigated by differential scanning calorimetry and laser flash apparatus. The results reveal that the thermal storage capacity of the Al–Si materials increases with increasing Si concentration. The melting point and latent heat of 45Al–40Si–15Fe and 17Al–53Si–30Ni are ∼869 °C and ∼562 J g −1 , and ∼1079 °C and ∼960 J g −1 , respectively. The measured thermal conductivity of Al–Si binary materials depend on Si concentration and is higher than 80 W m −1  K −1 from room temperature to 500 °C, which is almost two orders of magnitude higher than those of salts that are commonly used phase change material for thermal energy storage. - Highlights: • Six kinds of materials were investigated for thermal energy storage (550–1200 °C). • Partial melting of Al–Si materials show progressively changing temperatures. • Studied materials can be used in three different working temperature ranges. • Materials are potentially good candidates for thermal energy storage applications.

Storage at -80°C preserves the antioxidant capacity of preterm human milk.

Science.gov (United States)

Akdag, Arzu; Sari, Fatma Nur; Dizdar, Evrim Alyamac; Uras, Nurdan; Isikoglu, Semra; Erel, Ozcan; Dilmen, Ugur

2014-09-01

It is essential to establish optimum parameters for maintaining the quality of stored milk until the moment of consumption with minimal deterioration of its properties. The aim of the study was to evaluate total antioxidant capacity (TAC) and total oxidation status (TOS) of fresh and freeze-stored samples (at -80°C) of preterm human milk (HM). Samples of colostrum were collected from 98 healthy women within the first 4 days after delivery. The total milk volume collected (6 ml) was divided in two aliquot parts: 3 ml for the fresh analysis which was done immediately after the extraction and 3 ml for storage under freezing conditions at -80°C for three months. The antioxidant status and oxidative stress of the fresh and stored breast milk were assessed via determination of TAC and TOS levels. The mean gestational age and the birth weight of the infants were 31.26 ± 2.93 weeks and 1620 ± 581.91 g; respectively. There were no significant correlations between maternal age, route of delivery and milk oxidative stress. There was no significant difference between the levels of TAC, TOS and the oxidative stress index in fresh and freeze-stored samples of colostrum in preterm HM (p > 0.05). Freeze storage of preterm HM at -80°C for three months preserves the antioxidant capacity without changing oxidative status of HM, which could be noteworthy for the preterm infant nutrition. © 2014 Wiley Periodicals, Inc.

A strategy for load balancing in distributed storage systems

CERN Multimedia

CERN. Geneva

2012-01-01

Distributed storage systems are critical to the operation of the WLCG. These systems are not limited to fulfilling the long term storage requirements. They also serve data for computational analysis and other computational jobs. Distributed storage systems provide the ability to aggregate the storage and IO capacity of disks and tapes, but at the end of the day IO rate is still bound by the capabilities of the hardware, in particular the hard drives. Throughput of hard drives has increased dramatically over the decades, however for computational analysis IOPS is typically the limiting factor. To maximize return of investment, balancing IO load over available hardware is crucial. The task is made complicated by the common use of heterogeneous hardware and software environments that results from combining new and old hardware into a single storage system. This paper describes recent advances made in load balancing in the dCache distributed storage system. We describe a set of common requirements for load balan...

Metal oxide-carbon composites for energy conversion and storage

Science.gov (United States)

Perera, Sanjaya Dulip

The exponential growth of the population and the associated energy demand requires the development of new materials for sustainable energy conversion and storage. Expanding the use of renewable energy sources to generate electricity is still not sufficient enough to fulfill the current energy demand. Electricity generation by wind and solar is the most promising alternative energy resources for coal and oil. The first part of the dissertation addresses an alternative method for preparing TiO2 nanotube based photoanodes for DSSCs. This would involve smaller diameter TiO2 nanotubes (˜10 nm), instead of nanoparticles or electrochemically grown larger nanotubes. Moreover, TiO2 nanotube-graphene based photocatalysts were developed to treat model pollutants. In the second part of this dissertation, the development of electrical energy storage systems, which provide high storage capacity and power output using low cost materials are discussed. Among different types of energy storage systems, batteries are the most convenient method to store electrical energy. However, the low power performance of batteries limits the application in different types of electrical energy storage. The development of electrical energy storage systems, which provide high storage capacity and power output using low cost materials are discussed.

New technology and possible advances in energy storage

International Nuclear Information System (INIS)

Baker, John

2008-01-01

Energy storage technologies may be electrical or thermal. Electrical energy stores have an electrical input and output to connect them to the system of which they form part, while thermal stores have a thermal input and output. The principal electrical energy storage technologies described are electrochemical systems (batteries and flow cells), kinetic energy storage (flywheels) and potential energy storage, in the form of pumped hydro and compressed air. Complementary thermal storage technologies include those based on the sensible and latent heat capacity of materials, which include bulk and smaller-capacity hot and cold water storage systems, ice storage, phase change materials and specific bespoke thermal storage media. For the majority of the storage technologies considered here, the potential for fundamental step changes in performance is limited. For electrochemical systems, basic chemistry suggests that lithium-based technologies represent the pinnacle of cell development. This means that the greatest potential for technological advances probably lies in the incremental development of existing technologies, facilitated by advances in materials science, engineering, processing and fabrication. These considerations are applicable to both electrical and thermal storage. Such incremental developments in the core storage technologies are likely to be complemented and supported by advances in systems integration and engineering. Future energy storage technologies may be expected to offer improved energy and power densities, although, in practice, gains in reliability, longevity, cycle life expectancy and cost may be more significant than increases in energy/powerdensity per se

A study on the development of hypo-stoichiometric Zr-based hydrogen storage alloys with ultra-high capacity for anode material of Ni/MH secondary battery

Energy Technology Data Exchange (ETDEWEB)

Lee, S.-M.; Lee, H.; Kim, J.-H.; Lee, P.S.; Lee, J.-Y. [Korea Advanced Inst. of Science and Technology, Taejon (Korea). Dept. of Materials Science and Engineering

2000-08-10

Some hypo-stoichiometric Zr-based Laves phase alloys were prepared and studied from a viewpoint of discharge capacity for electrochemical application. After careful alloy design of ZrMn{sub 2}-based hydrogen storage alloys through changing their stoichiometry while substituting or adding some alloying elements, the Zr(Mn{sub 0.2}V{sub 0.2}Ni{sub 0.6}){sub 1.8} alloy reveals relatively good properties with regard to hydrogen storage capacity, hydrogen equilibrium pressure and electrochemical discharge capacity. In order to improve the discharge capacity and rate-capability, Zr is partially replaced by Ti. The discharge capacity of Zr{sub 1-x}Ti{sub x}(Mn{sub 0.2}V{sub 0.2}Ni{sub 0.6}){sub 1.8} (x=0.0, 0.2, 0.3, 0.4, 0.6) alloy electrodes at 30 C reaches a maximum value and decreases as the Ti fraction increases. In view of electrochemical and thermodynamic characteristics, the occurrence of a maximal phenomenon of the electrochemical discharge capacity of the alloy is attributed to a competition between decreasing hydrogen storage capacity and increasing rate-capability with Ti fraction. However, as the Ti fraction increases, the discharge capacity decreases drastically with repeated electrochemical cycling. Judging from the analysis of surface composition by Auger electron spectroscopy (AES), the rapid degradation with increasing Ti fraction in Zr-based alloy is ascribed to the fast growth of the oxygen-penetrated layer with cycling. Therefore, it is assured that the stoichiometry and Ti fraction should be optimized to obtain a good cycle life of the electrode maintaining high discharge capacity. On the basis of above results, the hydrogen storage capacity of the alloy with optimized composition (Zr{sub 0.65}Ti{sub 0.35}(Mn{sub 0.3}V{sub 0.14}Cr{sub 0.11}Ni{sub 0.65}){sub 1.76}) is about 1.68 wt% under 10 atm of equilibrium hydrogen pressure. (orig.)

Are carbon nanostructures an efficient hydrogen storage medium?

NARCIS (Netherlands)

Hirscher, M.; Becher, M.; Haluska, M.; Zeppelin, von F.; Chen, X.; Dettlaff-Weglikowska, U.; Roth, S.

2003-01-01

Literature data on the storage capacities of hydrogen in carbon nanostructures show a scatter over several orders of magnitude which cannot be solely explained by the limited quantity or purity of these novel nanoscale materials. With this in mind, this article revisits important experiments.

System Capacity Limits Introduced by Data Fusion on Cooperative Spectrum Sensing under Correlated Environments

DEFF Research Database (Denmark)

Pratas, Nuno; Marchetti, Nicola; Prasad, Neeli R.

2010-01-01

on cooperative sensing schemes. The analysis is supported by evaluation metrics which accounts for the perceived capacity limits. The analysis is performed along the data fusion chain, comparing several scenarios encompassing different degrees of environment correlation between the cluster nodes, number......Spectrum sensing, the cornerstone of the Cognitive Radio paradigm, has been the focus of intensive research, from which the main conclusion was that its performance can be greatly enhanced through the use of cooperative sensing schemes. Nevertheless, if a proper design of the cooperative scheme...... is not followed, then the use of cooperative schemes will introduce some limitations in the network perceived capacity. In this paper, we analyze the performance of a cooperative spectrum sensing scheme based on Data Fusion, by measuring the perceived capacity limits introduced by the use of Data Fusion...

Mental schemas hamper memory storage of goal-irrelevant information

NARCIS (Netherlands)

Sweegers, C.C.G.; Coleman, G.A.; van Poppel, E.A.M.; Cox, R.; Talamini, L.M.

2015-01-01

Mental schemas exert top-down control on information processing, for instance by facilitating the storage of schema-related information. However, given capacity-limits and competition in neural network processing, schemas may additionally exert their effects by suppressing information with low

Electricity storage using a thermal storage scheme

Energy Technology Data Exchange (ETDEWEB)

White, Alexander, E-mail: ajw36@cam.ac.uk [Hopkinson Laboratory, Cambridge University Engineering Department, Trumpington Street, Cambridge. CB2 1PZ (United Kingdom)

2015-01-22

The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater demand for large-scale electricity storage schemes. For example, the expanding fraction of electricity produced by wind turbines will require either backup or storage capacity to cover extended periods of wind lull. This paper describes a recently proposed storage scheme, referred to here as Pumped Thermal Storage (PTS), and which is based on “sensible heat” storage in large thermal reservoirs. During the charging phase, the system effectively operates as a high temperature-ratio heat pump, extracting heat from a cold reservoir and delivering heat to a hot one. In the discharge phase the processes are reversed and it operates as a heat engine. The round-trip efficiency is limited only by process irreversibilities (as opposed to Second Law limitations on the coefficient of performance and the thermal efficiency of the heat pump and heat engine respectively). PTS is currently being developed in both France and England. In both cases, the schemes operate on the Joule-Brayton (gas turbine) cycle, using argon as the working fluid. However, the French scheme proposes the use of turbomachinery for compression and expansion, whereas for that being developed in England reciprocating devices are proposed. The current paper focuses on the impact of the various process irreversibilities on the thermodynamic round-trip efficiency of the scheme. Consideration is given to compression and expansion losses and pressure losses (in pipe-work, valves and thermal reservoirs); heat transfer related irreversibility in the thermal reservoirs is discussed but not included in the analysis. Results are presented demonstrating how the various loss parameters and operating conditions influence the overall performance.

Analysis of multi cloud storage applications for resource constrained mobile devices

Directory of Open Access Journals (Sweden)

Rajeev Kumar Bedi

2016-09-01

Full Text Available Cloud storage, which can be a surrogate for all physical hardware storage devices, is a term which gives a reflection of an enormous advancement in engineering (Hung et al., 2012. However, there are many issues that need to be handled when accessing cloud storage on resource constrained mobile devices due to inherent limitations of mobile devices as limited storage capacity, processing power and battery backup (Yeo et al., 2014. There are many multi cloud storage applications available, which handle issues faced by single cloud storage applications. In this paper, we are providing analysis of different multi cloud storage applications developed for resource constrained mobile devices to check their performance on the basis of parameters as battery consumption, CPU usage, data usage and time consumed by using mobile phone device Sony Xperia ZL (smart phone on WiFi network. Lastly, conclusion and open research challenges in these multi cloud storage apps are discussed.

Small Form Factor Information Storage Devices for Mobile Applications in Korea

Science.gov (United States)

Park, Young-Pil; Park, No-Cheol; Kim, Chul-Jin

Recently, the ubiquitous environment in which anybody can reach a lot of information data without any limitations on the place and time has become an important social issue. There are two basic requirements in the field of information storage devices which have to be satisfied; the first is the demand for the improvement of memory capacity to manage the increased data capacity in personal and official purposes. The second is the demand for new development of information storage devices small enough to be applied to mobile multimedia digital electronics, including digital camera, PDA and mobile phones. To summarize, for the sake of mobile applications, it is necessary to develop information storage devices which have simultaneously a large capacity and a small size. Korea possesses the necessary infrastructure for developing such small sized information storage devices. It has a good digital market, major digital companies, and various research institutes. Nowadays, many companies and research institutes including university cooperate together in the research on small sized information storage devices. Thus, it is expected that small form factor optical disk drives will be commercialized in the very near future in Korea.

Magnesium mechanical alloys for hydrogen storage

International Nuclear Information System (INIS)

Ivanov, E.; Konstanchuk, I.; Stepanov, A.; Boldyrev, V.

1985-01-01

Metal hybrides are currently being used to store and handle hydrogen and its isotopes. They are also being tested in hydrogen compressors and in heat energy, refrigerators and in hydrogen and thermal storage devices. Metal hydrides have been proposed as one of the possible media for hydrogen storage to overcome the limitations of other techniques in regard to safety hydrogen weight and volume ration. The suitability of metal hybrides as a hydrogen storage media depends on a number of factors such as storage capacity, reactivity with hydrogen at various pressures and temperatures, and the cost of base materials. Magnesium based alloys are promising materials for storing hydrogen. They are generally made by argon melting and no attention has been payed to other fabrication techniques such as mechanical alloying or powder technique

Massive Memory Revisited: Limitations on Storage Capacity for Object Details in Visual Long-Term Memory

Science.gov (United States)

Cunningham, Corbin A.; Yassa, Michael A.; Egeth, Howard E.

2015-01-01

Previous work suggests that visual long-term memory (VLTM) is highly detailed and has a massive capacity. However, memory performance is subject to the effects of the type of testing procedure used. The current study examines detail memory performance by probing the same memories within the same subjects, but using divergent probing methods. The…

The H{sub 60}Si{sub 6}C{sub 54} heterofullerene as high-capacity hydrogen storage medium

Energy Technology Data Exchange (ETDEWEB)

Yong, Yongliang, E-mail: ylyong@haust.edu.cn [College of Physics and Engineering, Henan University of Science and Technology, Luoyang 471003 (China); Department of Physics, Zhejiang University, Hangzhou 310027 (China); Zhou, Qingxiao; Li, Xiaohong; Lv, Shijie [College of Physics and Engineering, Henan University of Science and Technology, Luoyang 471003 (China)

2016-07-15

With the great success in Si atoms doped C{sub 60} fullerene and the well-established methods for synthesis of hydrogenated carbon fullerenes, this leads naturally to wonder whether Si-doped fullerenes are possible for special applications such as hydrogen storage. Here by using first-principles calculations, we design a novel high-capacity hydrogen storage material, H{sub 60}Si{sub 6}C{sub 54} heterofullerene, and confirm its geometric stability. It is found that the H{sub 60}Si{sub 6}C{sub 54} heterofullerene has a large HOMO-LUMO gap and a high symmetry, indicating it is high chemically stable. Further, our finite temperature simulations indicate that the H{sub 60}Si{sub 6}C{sub 54} heterofullerene is thermally stable at 300 K. H{sub 2} molecules would enter into the cage from the Si-hexagon ring because of lower energy barrier. Through our calculation, a maximum of 21 H{sub 2} molecules can be stored inside the H{sub 60}Si{sub 6}C{sub 54} cage in molecular form, leading to a gravimetric density of 11.11 wt% for 21H{sub 2}@H{sub 60}Si{sub 6}C{sub 54} system, which suggests that the hydrogenated Si{sub 6}C{sub 54} heterofullerene could be suitable as a high-capacity hydrogen storage material.

Influence of capacity- and time-constrained intermediate storage in two-stage food production systems

DEFF Research Database (Denmark)

Akkerman, Renzo; van Donk, Dirk Pieter; Gaalman, Gerard

2007-01-01

In food processing, two-stage production systems with a batch processor in the first stage and packaging lines in the second stage are common and mostly separated by capacity- and time-constrained intermediate storage. This combination of constraints is common in practice, but the literature hardly...... of systems like this. Contrary to the common sense in operations management, the LPT rule is able to maximize the total production volume per day. Furthermore, we show that adding one tank has considerable effects. Finally, we conclude that the optimal setup frequency for batches in the first stage...... pays any attention to this. In this paper, we show how various capacity and time constraints influence the performance of a specific two-stage system. We study the effects of several basic scheduling and sequencing rules in the presence of these constraints in order to learn the characteristics...

APPLIED OPTICS. Overcoming Kerr-induced capacity limit in optical fiber transmission.

Science.gov (United States)

Temprana, E; Myslivets, E; Kuo, B P-P; Liu, L; Ataie, V; Alic, N; Radic, S

2015-06-26

Nonlinear optical response of silica imposes a fundamental limit on the information transfer capacity in optical fibers. Communication beyond this limit requires higher signal power and suppression of nonlinear distortions to prevent irreversible information loss. The nonlinear interaction in silica is a deterministic phenomenon that can, in principle, be completely reversed. However, attempts to remove the effects of nonlinear propagation have led to only modest improvements, and the precise physical mechanism preventing nonlinear cancellation remains unknown. We demonstrate that optical carrier stability plays a critical role in canceling Kerr-induced distortions and that nonlinear wave interaction in silica can be substantially reverted if optical carriers possess a sufficient degree of mutual coherence. These measurements indicate that fiber information capacity can be notably increased over previous estimates. Copyright © 2015, American Association for the Advancement of Science.

Discrete capacity limits and neuroanatomical correlates of visual short-term memory for objects and spatial locations.

Science.gov (United States)

Konstantinou, Nikos; Constantinidou, Fofi; Kanai, Ryota

2017-02-01

Working memory is responsible for keeping information in mind when it is no longer in view, linking perception with higher cognitive functions. Despite such crucial role, short-term maintenance of visual information is severely limited. Research suggests that capacity limits in visual short-term memory (VSTM) are correlated with sustained activity in distinct brain areas. Here, we investigated whether variability in the structure of the brain is reflected in individual differences of behavioral capacity estimates for spatial and object VSTM. Behavioral capacity estimates were calculated separately for spatial and object information using a novel adaptive staircase procedure and were found to be unrelated, supporting domain-specific VSTM capacity limits. Voxel-based morphometry (VBM) analyses revealed dissociable neuroanatomical correlates of spatial versus object VSTM. Interindividual variability in spatial VSTM was reflected in the gray matter density of the inferior parietal lobule. In contrast, object VSTM was reflected in the gray matter density of the left insula. These dissociable findings highlight the importance of considering domain-specific estimates of VSTM capacity and point to the crucial brain regions that limit VSTM capacity for different types of visual information. Hum Brain Mapp 38:767-778, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

40 CFR Table 1 to Subpart Bbbbbb... - Applicability Criteria, Emission Limits, and Management Practices for Storage Tanks

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 14 2010-07-01 2010-07-01 false Applicability Criteria, Emission Limits, and Management Practices for Storage Tanks 1 Table 1 to Subpart BBBBBB of Part 63 Protection of... Criteria, Emission Limits, and Management Practices for Storage Tanks If you own or operate Then you must 1...

Intergranular Cracking as a Major Cause of Long-Term Capacity Fading of Layered Cathodes.

Science.gov (United States)

Liu, Hao; Wolf, Mark; Karki, Khim; Yu, Young-Sang; Stach, Eric A; Cabana, Jordi; Chapman, Karena W; Chupas, Peter J

2017-06-14

Capacity fading has limited commercial layered Li-ion battery electrodes to NCA) electrode change after capacity fade following months of slow charge-discharge. The changes in the reactions that underpin energy storage after long-term cycling directly correlate to the capacity loss; heterogeneous reaction kinetics observed during extended cycles quantitatively account for the capacity loss. This reaction heterogeneity is ultimately attributed to intergranular fracturing that degrades the connectivity of subsurface grains within the polycrystalline NCA aggregate.

Hydrogen storage in clathrate hydrates: Current state of the art and future directions

International Nuclear Information System (INIS)

Veluswamy, Hari Prakash; Kumar, Rajnish; Linga, Praveen

2014-01-01

Hydrogen is looked upon as the next generation clean energy carrier, search for an efficient material and method for storing hydrogen has been pursued relentlessly. Improving hydrogen storage capacity to meet DOE targets has been challenging and research efforts are continuously put forth to achieve the set targets and to make hydrogen storage a commercially realizable process. This review comprehensively summarizes the state of the art experimental work conducted on the storage of hydrogen as hydrogen clathrates both at the molecular level and macroscopic level. It identifies future directions and challenges for this exciting area of research. Hydrogen storage capacities of different clathrate structures – sI, sII, sH, sVI and semi clathrates have been compiled and presented. In addition, promising new approaches for increasing hydrogen storage capacity have been described. Future directions for achieving increased hydrogen storage and process scale up have been outlined. Despite few limitations in storing hydrogen in the form of clathrates, this domain receives prominent attention due to more environmental-friendly method of synthesis, easy recovery of molecular hydrogen with minimum energy requirement, and improved safety of the process

Carbon materials for H{sub 2} storage

Energy Technology Data Exchange (ETDEWEB)

Zubizarreta, L.; Arenillas, A.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

2009-05-15

In this work a series of carbons with different structural and textural properties were characterised and evaluated for their application in hydrogen storage. The materials used were different types of commercial carbons: carbon fibers, carbon cloths, nanotubes, superactivated carbons, and synthetic carbons (carbon nanospheres and carbon xerogels). Their textural properties (i.e., surface area, pore size distribution, etc.) were related to their hydrogen adsorption capacities. These H{sub 2} storage capacities were evaluated by various methods (i.e., volumetric and gravimetric) at different temperatures and pressures. The differences between both methods at various operating conditions were evaluated and related to the textural properties of the carbon-based adsorbents. The results showed that temperature has a greater influence on the storage capacity of carbons than pressure. Furthermore, hydrogen storage capacity seems to be proportional to surface area, especially at 77 K. The micropore size distribution and the presence of narrow micropores also notably influence the H{sub 2} storage capacity of carbons. In contrast, morphological or structural characteristics have no influence on gravimetric storage capacity. If synthetic materials are used, the textural properties of carbon materials can be tailored for hydrogen storage. However, a larger pore volume would be needed in order to increase storage capacity. It seems very difficult approach to attain the DOE and EU targets only by physical adsorption on carbon materials. Chemical modification of carbons would seem to be a promising alternative approach in order to increase the capacities. (author)

Correction: Conceptual design of tetraazaporphyrin- and subtetraazaporphyrin-based functional nanocarbon materials: electronic structures, topologies, optical properties, and methane storage capacities.

Science.gov (United States)

Belosludov, Rodion V; Rhoda, Hannah M; Zhdanov, Ravil K; Belosludov, Vladimir R; Kawazoe, Yoshiyuki; Nemykin, Victor N

2017-08-02

Correction for 'Conceptual design of tetraazaporphyrin- and subtetraazaporphyrin-based functional nanocarbon materials: electronic structures, topologies, optical properties, and methane storage capacities' by Rodion V. Belosludov et al., Phys. Chem. Chem. Phys., 2016, 18, 13503-13518.

The meaning of different limiters relations for definig public transport routes capacity

OpenAIRE

Adam MOLECKI

2007-01-01

The mutual affecting of different limiters of capacity is a very important feature, which makes difficult the right appreciation of the transport systems. In most cases, there is no way to use procedures which define relations by correlation coefficients etc. Completely divergent character of limiters induce that only way of effective appreciation is modeling by Monte Carlo simulations.

Entropy, pricing and macroeconomics of pumped-storage systems

Science.gov (United States)

Karakatsanis, Georgios; Mamassis, Nikos; Koutsoyiannis, Demetris; Efstratiadis, Andreas

2014-05-01

We propose a pricing scheme for the enhancement of macroeconomic performance of pumped-storage systems, based on the statistical properties of both geophysical and economic variables. The main argument consists in the need of a context of economic values concerning the hub energy resource; defined as the resource that comprises the reference energy currency for all involved renewable energy sources (RES) and discounts all related uncertainty. In the case of pumped-storage systems the hub resource is the reservoir's water, as a benchmark for all connected intermittent RES. The uncertainty of all involved natural and economic processes is statistically quantifiable by entropy. It is the relation between the entropies of all involved RES that shapes the macroeconomic state of the integrated pumped-storage system. Consequently, there must be consideration on the entropy of wind, solar and precipitation patterns, as well as on the entropy of economic processes -such as demand preferences on either current energy use or storage for future availability. For pumped-storage macroeconomics, a price on the reservoir's capacity scarcity should also be imposed in order to shape a pricing field with upper and lower limits for the long-term stability of the pricing range and positive net energy benefits, which is the primary issue of the generalized deployment of pumped-storage technology. Keywords: Entropy, uncertainty, pricing, hub energy resource, RES, energy storage, capacity scarcity, macroeconomics

Improving hydrogen storage in Ni-doped carbon nanospheres

Energy Technology Data Exchange (ETDEWEB)

Zubizarreta, L.; Menendez, J.A.; Pis, J.J.; Arenillas, A. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

2009-04-15

The effect of nickel distribution and content in Ni-doped carbon nanospheres on hydrogen storage capacity under conditions of moderate temperature and pressure was studied. It was found that the nickel distribution, obtained by using different doping techniques and conditions, has a noticeable influence on hydrogen storage capacity. The samples with the most homogeneous nickel distribution, obtained by pre-oxidising the carbon nanospheres, displayed the highest storage capacity. In addition, storage capacity is influenced by the amount of nickel. It was found a higher storage capacity in samples containing 5 wt.% of Ni. This is due to the greater interactions between the nickel and the support that produce a higher activation of the solid through a spillover effect. (author)

Infection capacity of the pathogens Penicillium italicum and P. Expansum in orange during storage

Directory of Open Access Journals (Sweden)

Veljović Sonja P.

2017-01-01

Full Text Available Penicillium italicum and P. expansum are important pathogens causing decay in most fruits and vegetables. In this study, orange fruits were inoculated with these two species of fungus and stored 14 days with or without bagging, in a cold room for 11 days and 3 days at room temperature to determine the effect of bagging and infection capacities of both molds on oranges during storage. The results indicated that P. expansum can grow on orange peel with smaller colony diameter than P. italicum in bagged and unbagged fruits. Total soluble solids (TSS and firmness were not affected by bag. Gas composition of the bags showed low oxygen and high carbon dioxide concentration after fourteen days of storage. Bagged fruits decreased decay caused by P. italicum and weight loss, and delayed changes in firmness, TSS and acidity compared with control fruits. The study suggests that bagging may be a promising option for controlling decay, maintaining fruit quality and extending shelf-life of oranges.

Compact spent fuel storage at the Atucha I nuclear power plant

International Nuclear Information System (INIS)

Antonaccio, Carlos; Conde, Alberto; Flores, Alexis; Masciotra, Humberto; Sala, Guillermo; Zanni, Pablo

2000-01-01

The object of this report is to verify the possibility to increase the available storage of irradiated fuel assemblies, placed in the spent fuel pools of the Atucha I nuclear power plant. There is intends the realization of structural modifications in the storage bracket-suspension beam (single and double) for the upper and lower level of the four spent fuel pools. With these modifications that increase the storage capacity 25%, would arrive until the year 2014, it dates dear for the limit of the commercial operation of nuclear power plant. The increase of the capacity in function of the permissible stress for the supports of the bracket-suspension beam. They should be carried out 5000 re-accommodations of irradiated fuel assemblies. The task would demand approximately 3 years. (author)

FINAL REPORT: Room Temperature Hydrogen Storage in Nano-Confined Liquids

Energy Technology Data Exchange (ETDEWEB)

VAJO, JOHN

2014-06-12

DOE continues to seek solid-state hydrogen storage materials with hydrogen densities of ≥6 wt% and ≥50 g/L that can deliver hydrogen and be recharged at room temperature and moderate pressures enabling widespread use in transportation applications. Meanwhile, development including vehicle engineering and delivery infrastructure continues for compressed-gas hydrogen storage systems. Although compressed gas storage avoids the materials-based issues associated with solid-state storage, achieving acceptable volumetric densities has been a persistent challenge. This project examined the possibility of developing storage materials that would be compatible with compressed gas storage technology based on enhanced hydrogen solubility in nano-confined liquid solvents. These materials would store hydrogen in molecular form eliminating many limitations of current solid-state materials while increasing the volumetric capacity of compressed hydrogen storage vessels. Experimental methods were developed to study hydrogen solubility in nano-confined liquids. These methods included 1) fabrication of composites comprised of volatile liquid solvents for hydrogen confined within the nano-sized pore volume of nanoporous scaffolds and 2) measuring the hydrogen uptake capacity of these composites without altering the composite composition. The hydrogen storage capacities of these nano-confined solvent/scaffold composites were compared with bulk solvents and with empty scaffolds. The solvents and scaffolds were varied to optimize the enhancement in hydrogen solubility that accompanies confinement of the solvent. In addition, computational simulations were performed to study the molecular-scale structure of liquid solvent when confined within an atomically realistic nano-sized pore of a model scaffold. Confined solvent was compared with similar simulations of bulk solvent. The results from the simulations were used to formulate a mechanism for the enhanced solubility and to guide the

Increasing Sucrose Uptake Capacity of Wheat Grains Stimulates Storage Protein Synthesis1[W

Science.gov (United States)

Weichert, Nicola; Saalbach, Isolde; Weichert, Heiko; Kohl, Stefan; Erban, Alexander; Kopka, Joachim; Hause, Bettina; Varshney, Alok; Sreenivasulu, Nese; Strickert, Marc; Kumlehn, Jochen; Weschke, Winfriede; Weber, Hans

2010-01-01

Increasing grain sink strength by improving assimilate uptake capacity could be a promising approach toward getting higher yield. The barley (Hordeum vulgare) sucrose transporter HvSUT1 (SUT) was expressed under control of the endosperm-specific Hordein B1 promoter (HO). Compared with the wild type, transgenic HOSUT grains take up more sucrose (Suc) in vitro, showing that the transgene is functional. Grain Suc levels are not altered, indicating that Suc fluxes are influenced rather than steady-state levels. HOSUT grains have increased percentages of total nitrogen and prolamins, which is reflected in increased levels of phenylalanine, tyrosine, tryptophan, isoleucine, and leucine at late grain development. Transcript profiling indicates specific stimulation of prolamin gene expression at the onset of storage phase. Changes in gene expression and metabolite levels related to carbon metabolism and amino acid biosynthesis suggest deregulated carbon-nitrogen balance, which together indicate carbon sufficiency and relative depletion of nitrogen. Genes, deregulated together with prolamin genes, might represent candidates, which respond positively to assimilate supply and are related to sugar-starch metabolism, cytokinin and brassinosteroid functions, cell proliferation, and sugar/abscisic acid signaling. Genes showing inverse expression patterns represent potential negative regulators. It is concluded that HvSUT1 overexpression increases grain protein content but also deregulates the metabolic status of wheat (Triticum aestivum) grains, accompanied by up-regulated gene expression of positive and negative regulators related to sugar signaling and assimilate supply. In HOSUT grains, alternating stimulation of positive and negative regulators causes oscillatory patterns of gene expression and highlights the capacity and great flexibility to adjust wheat grain storage metabolism in response to metabolic alterations. PMID:20018590

Massive memory revisited: Limitations on storage capacity for object details in visual long-term memory

OpenAIRE

Cunningham, Corbin A.; Yassa, Michael A.; Egeth, Howard E.

2015-01-01

Previous work suggests that visual long-term memory (VLTM) is highly detailed and has a massive capacity. However, memory performance is subject to the effects of the type of testing procedure used. The current study examines detail memory performance by probing the same memories within the same subjects, but using divergent probing methods. The results reveal that while VLTM representations are typically sufficient to support performance when the procedure probes gist-based information, they...

The meaning of different limiters relations for definig public transport routes capacity

Directory of Open Access Journals (Sweden)

Adam MOLECKI

2007-01-01

Full Text Available The mutual affecting of different limiters of capacity is a very important feature, which makes difficult the right appreciation of the transport systems. In most cases, there is no way to use procedures which define relations by correlation coefficients etc. Completely divergent character of limiters induce that only way of effective appreciation is modeling by Monte Carlo simulations.

Nanoscale Chemical Processes Affecting Storage Capacities and Seals during Geologic CO2 Sequestration.

Science.gov (United States)

Jun, Young-Shin; Zhang, Lijie; Min, Yujia; Li, Qingyun

2017-07-18

Geologic CO 2 sequestration (GCS) is a promising strategy to mitigate anthropogenic CO 2 emission to the atmosphere. Suitable geologic storage sites should have a porous reservoir rock zone where injected CO 2 can displace brine and be stored in pores, and an impermeable zone on top of reservoir rocks to hinder upward movement of buoyant CO 2 . The injection wells (steel casings encased in concrete) pass through these geologic zones and lead CO 2 to the desired zones. In subsurface environments, CO 2 is reactive as both a supercritical (sc) phase and aqueous (aq) species. Its nanoscale chemical reactions with geomedia and wellbores are closely related to the safety and efficiency of CO 2 storage. For example, the injection pressure is determined by the wettability and permeability of geomedia, which can be sensitive to nanoscale mineral-fluid interactions; the sealing safety of the injection sites is affected by the opening and closing of fractures in caprocks and the alteration of wellbore integrity caused by nanoscale chemical reactions; and the time scale for CO 2 mineralization is also largely dependent on the chemical reactivities of the reservoir rocks. Therefore, nanoscale chemical processes can influence the hydrogeological and mechanical properties of geomedia, such as their wettability, permeability, mechanical strength, and fracturing. This Account reviews our group's work on nanoscale chemical reactions and their qualitative impacts on seal integrity and storage capacity at GCS sites from four points of view. First, studies on dissolution of feldspar, an important reservoir rock constituent, and subsequent secondary mineral precipitation are discussed, focusing on the effects of feldspar crystallography, cations, and sulfate anions. Second, interfacial reactions between caprock and brine are introduced using model clay minerals, with focuses on the effects of water chemistries (salinity and organic ligands) and water content on mineral dissolution and

Titanium-decorated graphene for high-capacity hydrogen storage studied by density functional simulations

International Nuclear Information System (INIS)

Liu Yali; Ren Ling; He Yao; Cheng Haiping

2010-01-01

We present results of density functional theory (DFT) calculations of the adsorption of hydrogen molecules on Ti-decorated graphene. Our results indicate that the binding energies of molecular hydrogen on Ti-decorated graphene can be dramatically enhanced to 0.23-0.60 eV. The hybridization of the Ti 3d orbitals with the H 2 σ and σ* orbitals plays a central role in the enhanced binding. There is also a contribution from the attractive interaction between the surface dipole and the dipole of polarized H 2 . It can be expected that Ti-decorated graphene could be considered as a potential high-capacity hydrogen storage medium.

Low pressure storage of natural gas on activated carbon

Science.gov (United States)

Wegrzyn, J.; Wiesmann, H.; Lee, T.

The introduction of natural gas to the transportation energy sector offers the possibility of displacing imported oil with an indigenous fuel. The barrier to the acceptance of natural gas vehicles (NGV) is the limited driving range due to the technical difficulties of on-board storage of a gaseous fuel. In spite of this barrier, compressed natural gas (CNG) vehicles are today being successfully introduced into the market place. The purpose of this work is to demonstrate an adsorbent natural gas (ANG) storage system as a viable alternative to CNG storage. It can be argued that low pressure ANG has reached near parity with CNG, since the storage capacity of CNG (2400 psi) is rated at 190 V/V, while low pressure ANG (500 psi) has reached storage capacities of 180 V/V in the laboratory. A program, which extends laboratory results to a full-scale vehicle test, is necessary before ANG technology will receive widespread acceptance. The objective of this program is to field test a 150 V/V ANG vehicle in FY 1994. As a start towards this goal, carbon adsorbents have been screened by Brookhaven for their potential use in a natural gas storage system. This paper reports on one such carbon, trade name Maxsorb, manufactured by Kansai Coke under an Amoco license.

Content of Total Phenolics, Flavan-3-Ols and Proanthocyanidins, Oxidative Stability and Antioxidant Capacity of Chocolate During Storage

Science.gov (United States)

Komes, Draženka; Gorjanović, Stanislava; Belščak-Cvitanović, Ana; Pezo, Lato; Pastor, Ferenc; Ostojić, Sanja; Popov-Raljić, Jovanka; Sužnjević, Desanka

2016-01-01

Summary Antioxidant (AO) capacity of chocolates with 27, 44 and 75% cocoa was assessed after production and during twelve months of storage by direct current (DC) polarographic assay, based on the decrease of anodic current caused by the formation of hydroxo-perhydroxyl mercury(II) complex (HPMC) in alkaline solutions of hydrogen peroxide at potentials of mercury oxidation, and two spectrophotometric assays. Relative antioxidant capacity index (RACI) was calculated by taking the average value of the AO assay (the sample mass in all assays was identical). Oxidative stability of chocolate fat was determined by differential scanning calorimetry. Measured parameters and RACI were correlated mutually and with the content of total phenols (Folin-Ciocalteu assay), flavan-3-ols (vanillin and p-dimethylaminocinnamaldehyde assay) and proanthocyanidins (modified Bate-Smith assay). During storage, the studied functional and health-related characteristics remained unchanged. Amongst applied AO assays, the DC polarographic one, whose validity was confirmed by two-way ANOVA and F-test, correlated most significantly with oxidative stability (oxidation onset temperature and induction time). In addition, principal component analysis was applied to characterise chocolate types. PMID:27904388

Content of Total Phenolics, Flavan-3-Ols and Proanthocyanidins, Oxidative Stability and Antioxidant Capacity of Chocolate During Storage

Directory of Open Access Journals (Sweden)

Draženka Komes

2016-01-01

Full Text Available Antioxidant (AO capacity of chocolates with 27, 44 and 75 % cocoa was assessed after production and during twelve months of storage by direct current (DC polarographic assay, based on the decrease of anodic current caused by the formation of hydroxo-perhydroxyl mercury(II complex (HPMC in alkaline solutions of hydrogen peroxide at potentials of mercury oxidation, and two spectrophotometric assays. Relative antioxidant capacity index (RACI was calculated by taking the average value of the AO assay (the sample mass in all assays was identical. Oxidative stability of chocolate fat was determined by differential scanning calorimetry. Measured parameters and RACI were correlated mutually and with the content of total phenols (Folin-Ciocalteu assay, flavan-3-ols (vanillin and p-dimethylaminocinnamaldehyde assay and proanthocyanidins (modified Bate-Smith assay. During storage, the studied functional and health-related characteristics remained unchanged. Amongst applied AO assays, the DC polarographic one, whose validity was confirmed by two-way ANOVA and F-test, correlated most significantly with oxidative stability (oxidation onset temperature and induction time. In addition, principal component analysis was applied to characterise chocolate types.

Electrode surface engineering by atomic layer deposition: A promising pathway toward better energy storage

KAUST Repository

Ahmed, Bilal

2016-04-29

Research on electrochemical energy storage devices including Li ion batteries (LIBs), Na ion batteries (NIBs) and supercapacitors (SCs) has accelerated in recent years, in part because developments in nanomaterials are making it possible to achieve high capacities and energy and power densities. These developments can extend battery life in portable devices, and open new markets such as electric vehicles and large-scale grid energy storage. It is well known that surface reactions largely determine the performance and stability of electrochemical energy storage devices. Despite showing impressive capacities and high energy and power densities, many of the new nanostructured electrode materials suffer from limited lifetime due to severe electrode interaction with electrolytes or due to large volume changes. Hence control of the surface of the electrode material is essential for both increasing capacity and improving cyclic stability of the energy storage devices.Atomic layer deposition (ALD) which has become a pervasive synthesis method in the microelectronics industry, has recently emerged as a promising process for electrochemical energy storage. ALD boasts excellent conformality, atomic scale thickness control, and uniformity over large areas. Since ALD is based on self-limiting surface reactions, complex shapes and nanostructures can be coated with excellent uniformity, and most processes can be done below 200. °C. In this article, we review recent studies on the use of ALD coatings to improve the performance of electrochemical energy storage devices, with particular emphasis on the studies that have provided mechanistic insight into the role of ALD in improving device performance. © 2016 Elsevier Ltd.

Utilizing ZFS for the Storage of Acquired Data

International Nuclear Information System (INIS)

Pugh, C.; Henderson, P.; Silber, K.; Carroll, T.; Ying, K.

2009-01-01

Every day, the amount of data that is acquired from plasma experiments grows dramatically. It has become difficult for systems administrators to keep up with the growing demand for hard drive storage space. In the past, project storage has been supplied using UNIX filesystem (ufs) partitions. In order to increase the size of the disks using this system, users were required to discontinue use of the disk, so the existing data could be transferred to a disk of larger capacity or begin use of a completely new and separate disk, thus creating a segmentation of data storage. With the application of ZFS pools, the data capacity woes are over. ZFS provides simple administration that eliminates the need to unmount to resize, or transfer data to a larger disk. With a storage limit of 16 Exabytes (1018), ZFS provides immense scalability. Utilizing ZFS as the new project disk file system, users and administrators can eliminate time wasted waiting for data to transfer from one hard drive to another, and also enables more efficient use of disk space, as system administrators need only allocate what is presently required. This paper will discuss the application and benefits of using ZFS as an alternative to traditional data access and storage in the fusion environment.

Towards the Fourier limit on the super-ACO Storage Ring FEL

International Nuclear Information System (INIS)

Couprie, M.E.; De Ninno, G.; Moneron, G.; Nutarelli, D.; Hirsch, M.; Garzella, D.; Renault, E.; Roux, R.; Thomas, C.

2001-01-01

Systematic studies on the Free Electron Laser (FEL) line and micropulse have been performed on the Super-ACO storage ring FEL with a monochromator and a double-sweep streak camera under various conditions of operation (detuning, 'CW' and Q-switched mode). From these data, it appears that the FEL is usually operated very close to the Fourier limit

Towards the Fourier limit on the super-ACO Storage Ring FEL

CERN Document Server

Couprie, Marie Emmanuelle; Garzella, D; Hirsch, M; Moneron, G; Nutarelli, D; Renault, E; Roux, R; Thomas, C

2001-01-01

Systematic studies on the Free Electron Laser (FEL) line and micropulse have been performed on the Super-ACO storage ring FEL with a monochromator and a double-sweep streak camera under various conditions of operation (detuning, 'CW' and Q-switched mode). From these data, it appears that the FEL is usually operated very close to the Fourier limit.

Hydrogen transport and storage in engineered glass microspheres

Energy Technology Data Exchange (ETDEWEB)

Rambach, G.D.

1994-04-20

New, high-strength, hollow, glass microspheres filled with pressurized hydrogen exhibit storage densities which make them attractive for bulk hydrogen storage and transport. The hoop stress at failure of our engineered glass microspheres is about 150,000 psi, permitting a three-fold increase in pressure limit and storage capacity above commercial microspheres, which fail at wall stresses of 50,000 psi. For this project, microsphere material and structure will be optimized for storage capacity and charge/discharge kinetics to improve their commercial practicality. Microsphere production scale up will be performed, directed towards large-scale commercial use. Our analysis relating glass microspheres for hydrogen transport with infrastructure and economics` indicate that pressurized microspheres can be economically competitive with other forms of bulk rail and truck transport such as hydride beds, cryocarbons and pressurized tube transports. For microspheres made from advanced materials and processes, analysis will also be performed to identify the appropriate applications of the microspheres considering property variables, and different hydrogen infrastructure, end use, production and market scenarios. This report presents some of the recent modelling results for large beds of glass microspheres in hydrogen storage applications. It includes plans for experiments to identify the properties relevant to large-bed hydrogen transport and storage applications, of the best, currently producible, glass microspheres. This work began in March, 1994. Project successes will be manifest in the matching of cur-rent glass microspheres with a useful application in hydrogen bulk transport and storage, and in developing microsphere materials and processes that increase the storage density and reduce the storage energy requirement.

Rejuvenation capacity of red blood cells in additive solutions over long-term storage.

Science.gov (United States)

Meyer, Erin K; Dumont, Deborah F; Baker, Sharry; Dumont, Larry J

2011-07-01

Red blood cells (RBCs) are Food and Drug Administration (FDA)-approved for 42-day storage with the use of additive solutions (ASs). However, adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG) levels in the RBCs decline over this time. These constituents may be restored by treatment with rejuvenation (REJ) solutions. This study was done to assess the response capability of RBCs from 30 to 120 days of storage in three FDA-licensed RBC storage solutions after incubation with a rejuvenating solution of pyruvate, inosine, phosphate, and adenine. Three units each of RBCs in approved AS (AS-1 [Adsol, Fenwal, Inc.], AS-3 [Nutricel, Medsep Corp.], and AS-5 [Optisol, Terumo Corp.]) were stored under standard conditions at 1 to 6°C for up to 120 days. Aliquots (4 mL) on Days 30, 42, 60, 80, 100, and 120 (± 2 days) were REJ by incubating with Rejuvesol (Encyte Corp.). Control untreated and REJ aliquots were extracted using perchloric acid and stored at -80°C until assayed for 2,3-DPG and ATP. RBCs responded to REJ by increasing DPG and ATP contents. The response declined linearly at 0.070 ± 0.008 µmol DPG/g hemoglobin (Hb)/day and 0.035 ± 0.004 µmol ATP/g Hb/day with no differences between ASs. We conclude that Rejuvesol is able to restore ATP and 2,3-DPG levels in RBCs stored up to 120 days in AS. The response diminishes as storage time increases. This rejuvenation (REJ) capability does not seem useful for routine assessment of RBC anabolic capacity in research programs, but may be useful to the investigator when studying unique and novel treatment methods. © 2011 American Association of Blood Banks.

A Model To Estimate Carbon Dioxide Injectivity and Storage Capacity for Geological Sequestration in Shale Gas Wells.

Science.gov (United States)

Edwards, Ryan W J; Celia, Michael A; Bandilla, Karl W; Doster, Florian; Kanno, Cynthia M

2015-08-04

Recent studies suggest the possibility of CO2 sequestration in depleted shale gas formations, motivated by large storage capacity estimates in these formations. Questions remain regarding the dynamic response and practicality of injection of large amounts of CO2 into shale gas wells. A two-component (CO2 and CH4) model of gas flow in a shale gas formation including adsorption effects provides the basis to investigate the dynamics of CO2 injection. History-matching of gas production data allows for formation parameter estimation. Application to three shale gas-producing regions shows that CO2 can only be injected at low rates into individual wells and that individual well capacity is relatively small, despite significant capacity variation between shale plays. The estimated total capacity of an average Marcellus Shale well in Pennsylvania is 0.5 million metric tonnes (Mt) of CO2, compared with 0.15 Mt in an average Barnett Shale well. Applying the individual well estimates to the total number of existing and permitted planned wells (as of March, 2015) in each play yields a current estimated capacity of 7200-9600 Mt in the Marcellus Shale in Pennsylvania and 2100-3100 Mt in the Barnett Shale.

Development of hydrogen storage systems using sodium alanate

Energy Technology Data Exchange (ETDEWEB)

Lozano Martinez, Gustavo Adolfo

2010-12-06

the model for numerical predictions. This approach describes the material as a mixture composed of different types of reacting materials, which avoids the use of correction terms for the experimental capacities, as it is commonly done in other empirical sorption models for metal hydrides. To study cycling, kinetics and heat transfer in hydride tanks up to kg scale, a hydrogen tank station was designed and constructed. The sorption behaviour of sodium alanate storage tanks was evaluated, and it was confirmed, that the addition of expanded graphite improves the heat transfer resulting in faster hydrogenation kinetics. The hydrogen sorption process of practical systems based on hydride beds was modelled for the simultaneous sub-processes of hydrogen transport, intrinsic reaction and heat transfer. Based on the modelling equations, a comparative resistance analysis was developed in order to quantify the effect of each sub-process on the overall sorption kinetics in sodium alanate beds. It was found that large size systems are mainly heat transfer limited. Moreover, on the basis of the modelling equations, a numerical simulation was developed. The simulation was validated with the experimental results obtained in this work. Optimisation of the volumetric hydrogen storage capacity of sodium alanate based hydrogen storage tanks is experimentally demonstrated by powder compaction. Quite interesting results are discovered on the sorption behaviour of these manufactured compacts: sorption improvement and volumetric expansion of the pellets through cycling as well as enhanced volumetric and gravimetric hydrogen storage capacity of the material. To conclude the work, a tubular tank filled with sodium alanate material was theoretically optimised towards its gravimetric hydrogen storage capacity using the developed simulation and the results obtained during this investigation. The optimisation process includes the evaluation of compaction, the addition of expanded graphite and

Analysis on applicable error-correcting code strength of storage class memory and NAND flash in hybrid storage

Science.gov (United States)

Matsui, Chihiro; Kinoshita, Reika; Takeuchi, Ken

2018-04-01

A hybrid of storage class memory (SCM) and NAND flash is a promising technology for high performance storage. Error correction is inevitable on SCM and NAND flash because their bit error rate (BER) increases with write/erase (W/E) cycles, data retention, and program/read disturb. In addition, scaling and multi-level cell technologies increase BER. However, error-correcting code (ECC) degrades storage performance because of extra memory reading and encoding/decoding time. Therefore, applicable ECC strength of SCM and NAND flash is evaluated independently by fixing ECC strength of one memory in the hybrid storage. As a result, weak BCH ECC with small correctable bit is recommended for the hybrid storage with large SCM capacity because SCM is accessed frequently. In contrast, strong and long-latency LDPC ECC can be applied to NAND flash in the hybrid storage with large SCM capacity because large-capacity SCM improves the storage performance.

Spent fuel storage requirements 1993--2040

International Nuclear Information System (INIS)

1994-09-01

Historical inventories of spent fuel are combined with U.S. Department of Energy (DOE) projections of future discharges from commercial nuclear reactors in the United States to provide estimates of spent fuel storage requirements through the year 2040. The needs are estimated for storage capacity beyond that presently available in the reactor storage pools. These estimates incorporate the maximum capacities within current and planned in-pool storage facilities and any planned transshipments of spent fuel to other reactors or facilities. Existing and future dry storage facilities are also discussed. The nuclear utilities provide historical data through December 1992 on the end of reactor life are based on the DOE/Energy Information Administration (EIA) estimates of future nuclear capacity, generation, and spent fuel discharges

Evaluating the use of biomass energy with carbon capture and storage in low emission scenarios

Science.gov (United States)

Vaughan, Naomi E.; Gough, Clair; Mander, Sarah; Littleton, Emma W.; Welfle, Andrew; Gernaat, David E. H. J.; van Vuuren, Detlef P.

2018-04-01

Biomass Energy with Carbon Capture and Storage (BECCS) is heavily relied upon in scenarios of future emissions that are consistent with limiting global mean temperature increase to 1.5 °C or 2 °C above pre-industrial. These temperature limits are defined in the Paris Agreement in order to reduce the risks and impacts of climate change. Here, we explore the use of BECCS technologies in a reference scenario and three low emission scenarios generated by an integrated assessment model (IMAGE). Using these scenarios we investigate the feasibility of key implicit and explicit assumptions about these BECCS technologies, including biomass resource, land use, CO2 storage capacity and carbon capture and storage (CCS) deployment rate. In these scenarios, we find that half of all global CO2 storage required by 2100 occurs in USA, Western Europe, China and India, which is compatible with current estimates of regional CO2 storage capacity. CCS deployment rates in the scenarios are very challenging compared to historical rates of fossil, renewable or nuclear technologies and are entirely dependent on stringent policy action to incentivise CCS. In the scenarios, half of the biomass resource is derived from agricultural and forestry residues and half from dedicated bioenergy crops grown on abandoned agricultural land and expansion into grasslands (i.e. land for forests and food production is protected). Poor governance of the sustainability of bioenergy crop production can significantly limit the amount of CO2 removed by BECCS, through soil carbon loss from direct and indirect land use change. Only one-third of the bioenergy crops are grown in regions associated with more developed governance frameworks. Overall, the scenarios in IMAGE are ambitious but consistent with current relevant literature with respect to assumed biomass resource, land use and CO2 storage capacity.

A shared, flexible neural map architecture reflects capacity limits in both visual short-term memory and enumeration.

Science.gov (United States)

Knops, André; Piazza, Manuela; Sengupta, Rakesh; Eger, Evelyn; Melcher, David

2014-07-23

Human cognition is characterized by severe capacity limits: we can accurately track, enumerate, or hold in mind only a small number of items at a time. It remains debated whether capacity limitations across tasks are determined by a common system. Here we measure brain activation of adult subjects performing either a visual short-term memory (vSTM) task consisting of holding in mind precise information about the orientation and position of a variable number of items, or an enumeration task consisting of assessing the number of items in those sets. We show that task-specific capacity limits (three to four items in enumeration and two to three in vSTM) are neurally reflected in the activity of the posterior parietal cortex (PPC): an identical set of voxels in this region, commonly activated during the two tasks, changed its overall response profile reflecting task-specific capacity limitations. These results, replicated in a second experiment, were further supported by multivariate pattern analysis in which we could decode the number of items presented over a larger range during enumeration than during vSTM. Finally, we simulated our results with a computational model of PPC using a saliency map architecture in which the level of mutual inhibition between nodes gives rise to capacity limitations and reflects the task-dependent precision with which objects need to be encoded (high precision for vSTM, lower precision for enumeration). Together, our work supports the existence of a common, flexible system underlying capacity limits across tasks in PPC that may take the form of a saliency map. Copyright © 2014 the authors 0270-6474/14/349857-10$15.00/0.

Solvothermal and electrochemical synthetic method of HKUST-1 and its methane storage capacity

Science.gov (United States)

Wahyu Lestari, Witri; Adreane, Marisa; Purnawan, Candra; Fansuri, Hamzah; Widiastuti, Nurul; Budi Rahardjo, Sentot

2016-02-01

A comparison synthetic strategy of Metal-Organic Frameworks, namely, Hongkong University of Techhnology-1 {HKUST-1[Cu3(BTC)]2} (BTC = 1,3,5-benzene-tri-carboxylate) through solvothermal and electrochemical method in ethanol:water (1:1) has been conducted. The obtained material was analyzed using powder X-ray diffraction, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermo-Gravimetric Analysis (TGA) and Surface Area Analysis (SAA). While the voltage in the electrochemical method are varied, ranging from 12 to 15 Volt. The results show that at 15 V the texture of the material has the best degree of crystallinity and comparable with solvothermal product. This indicated from XRD data and supported by the SEM image to view the morphology. The thermal stability of the synthesized compounds is up to 320 °C. The shape of the nitrogen sorption isotherm of the compound corresponds to type I of the IUPAC adsorption isotherm classification for microporous materials with BET surface area of 629.2 and 324.3 m2/g (for solvothermal and electrochemical product respectively) and promising for gas storage application. Herein, the methane storage capacities of these compounds are also tested.

Block Storage Service: Status and Performance

CERN Document Server

Van der Ster, Daniel

2014-01-01

This memo summarizes the current status of the Ceph block storage service as it is used for OpenStack Cinder Volumes and Glance Images as of May 2014. We present the block storage activity on the current cluster, measuring IOPS and latencies, and present a cost/benefit analysis of using SSDs to optimize the cost and performance efficiency of the service. During tests in collaboration with IT-CF, we have concluded that by adding SSDs as the synchronous write journals (used to guarantee data durability), we are able increase the IOPS capacity by 4-5 times, at a cost of decreasing the available volume by 20%. Further, the testing has shown that the Ceph implementation is able to operate at the limit of the hardware performance; software-induced performance limitations were not yet observed in either the spinning disk or SSD configurations. In addition, we believe that increasing small write performance with SSDs is applicable only to the block storage use-case; high-bandwidth use-cases such as physics data stora...

The limits to solar thermal electricity

International Nuclear Information System (INIS)

Trainer, Ted

2014-01-01

The potential and limits of solar thermal power systems depend primarily on their capacity to meet electricity demand in mid-winter, and the associated cost, storage and other implications. Evidence on output and costs is analysed. Most attention is given to central receivers. Problems of low radiation levels, embodied energy costs, variability and storage are discussed and are found to set significant difficulties for large scale solar thermal supply in less than ideal latitudes and seasons. It is concluded that for solar thermal systems to meet a large fraction of anticipated global electricity demand in winter would involve prohibitive capital costs. - Highlights: • Output and capital cost data for various solar thermal technologies is examined. • Special attention is given to performance in winter. • Attention is also given to the effect of solar intermittency. • Implications for storage are considered. • It is concluded that there are significant limits to solar thermal power

The frontal eye fields limit the capacity of visual short-term memory in rhesus monkeys.

Science.gov (United States)

Lee, Kyoung-Min; Ahn, Kyung-Ha

2013-01-01

The frontal eye fields (FEF) in rhesus monkeys have been implicated in visual short-term memory (VSTM) as well as control of visual attention. Here we examined the importance of the area in the VSTM capacity and the relationship between VSTM and attention, using the chemical inactivation technique and multi-target saccade tasks with or without the need of target-location memory. During FEF inactivation, serial saccades to targets defined by color contrast were unaffected, but saccades relying on short-term memory were impaired when the target count was at the capacity limit of VSTM. The memory impairment was specific to the FEF-coded retinotopic locations, and subject to competition among targets distributed across visual fields. These results together suggest that the FEF plays a crucial role during the entry of information into VSTM, by enabling attention deployment on targets to be remembered. In this view, the memory capacity results from the limited availability of attentional resources provided by FEF: The FEF can concurrently maintain only a limited number of activations to register the targets into memory. When lesions render part of the area unavailable for activation, the number would decrease, further reducing the capacity of VSTM.

Development of a global electricity supply model and investigation of electricity supply by renewable energies with a focus on energy storage requirements for Europe

Energy Technology Data Exchange (ETDEWEB)

Troendle, Tobias Wolfgang

2014-12-12

Electricity supply at present requires about 38% of the global primary energy demand and it is likely to rise further in the coming decades. Facing major problems, such as limited resources of fuels and an ongoing anthropogenic climate change, a sustainable electricity supply based on renewable energies is absolutely vital. Wind and solar power will play an extensive role in future supplies but require energy storage capacities to meet electricity demand. To investigate the relationship of power plant mix and required energy storage capacity, a computer model based on global weather data has been developed to enable the simulation of electricity supply scenarios by up to ten different power plant types for various regions. The focus of the investigation has been on the energy storage requirements of an electricity supply for Europe by wind and solar power. The minimum required energy storage capacity for a totally weather dependent electricity supply occurs at a ratio of 30% wind and 70% photovoltaic (PV) power plant capacity installed. Thus, the required energy storage capacity rises from a transition of to-day's electricity supply to the afore-mentioned 100% renewable wind and PV scenario exponentially to about 150 TWh (3.8% of the annual electricity demand). The installation of additional excess wind and PV power plant capacity was seen to be an efficient way to reduce the required energy storage. Already 10% excess capacity lead to a reduction by 50% of the required storage capacity. To use different storage technologies in an optimised way in terms of storage capacity and efficiency, the storage tasks can be separated into a daily and a seasonal usage. While the seasonal storage capacity has to be about two orders of magnitude larger than the required capacity of the storage for the daily cycle, the sum of stored energy during one year is almost equal for the long and short time storage. In summary, an electricity supply by wind and PV power was shown to

Development of a global electricity supply model and investigation of electricity supply by renewable energies with a focus on energy storage requirements for Europe

International Nuclear Information System (INIS)

Troendle, Tobias Wolfgang

2014-01-01

Electricity supply at present requires about 38% of the global primary energy demand and it is likely to rise further in the coming decades. Facing major problems, such as limited resources of fuels and an ongoing anthropogenic climate change, a sustainable electricity supply based on renewable energies is absolutely vital. Wind and solar power will play an extensive role in future supplies but require energy storage capacities to meet electricity demand. To investigate the relationship of power plant mix and required energy storage capacity, a computer model based on global weather data has been developed to enable the simulation of electricity supply scenarios by up to ten different power plant types for various regions. The focus of the investigation has been on the energy storage requirements of an electricity supply for Europe by wind and solar power. The minimum required energy storage capacity for a totally weather dependent electricity supply occurs at a ratio of 30% wind and 70% photovoltaic (PV) power plant capacity installed. Thus, the required energy storage capacity rises from a transition of to-day's electricity supply to the afore-mentioned 100% renewable wind and PV scenario exponentially to about 150 TWh (3.8% of the annual electricity demand). The installation of additional excess wind and PV power plant capacity was seen to be an efficient way to reduce the required energy storage. Already 10% excess capacity lead to a reduction by 50% of the required storage capacity. To use different storage technologies in an optimised way in terms of storage capacity and efficiency, the storage tasks can be separated into a daily and a seasonal usage. While the seasonal storage capacity has to be about two orders of magnitude larger than the required capacity of the storage for the daily cycle, the sum of stored energy during one year is almost equal for the long and short time storage. In summary, an electricity supply by wind and PV power was shown to

The HYDROMED model and its application to semi-arid Mediterranean catchments with hill reservoirs 3: Reservoir storage capacity and probability of failure model

Directory of Open Access Journals (Sweden)

R. Ragab

2001-01-01

Full Text Available This paper addresses the issue of "what reservoir storage capacity is required to maintain a yield with a given probability of failure?". It is an important issue in terms of construction and cost. HYDROMED offers a solution based on the modified Gould probability matrix method. This method has the advantage of sampling all years data without reference to the sequence and is therefore particularly suitable for catchments with patchy data. In the HYDROMED model, the probability of failure is calculated on a monthly basis. The model has been applied to the El-Gouazine catchment in Tunisia using a long rainfall record from Kairouan together with the estimated Hortonian runoff, class A pan evaporation data and estimated abstraction data. Generally, the probability of failure differed from winter to summer. Generally, the probability of failure approaches zero when the reservoir capacity is 500,000 m3. The 25% probability of failure (75% success is achieved with a reservoir capacity of 58,000 m3 in June and 95,000 m3 in January. The probability of failure for a 240,000 m3 capacity reservoir (closer to storage capacity of El-Gouazine 233,000 m3, is approximately 5% in November, December and January, 3% in March, and 1.1% in May and June. Consequently there is no high risk of El-Gouazine being unable to meet its requirements at a capacity of 233,000 m3. Subsequently the benefit, in terms of probability of failure, by increasing the reservoir volume of El-Gouazine to greater than the 250,000 m3 is not high. This is important for the design engineers and the funding organizations. However, the analysis is based on the existing water abstraction policy, absence of siltation rate data and on the assumption that the present climate will prevail during the lifetime of the reservoir. Should these conditions change, a new analysis should be carried out. Keywords: HYDROMED, reservoir, storage capacity, probability of failure, Mediterranean

High capacity hydrogen storage nanocomposite materials

Science.gov (United States)

Zidan, Ragaiy; Wellons, Matthew S.

2017-12-12

A novel hydrogen absorption material is provided comprising a mixture of a lithium hydride with a fullerene. The subsequent reaction product provides for a hydrogen storage material which reversibly stores and releases hydrogen at temperatures of about 270.degree. C.

Electrochemically fabricated polypyrrole-cobalt-oxygen coordination complex as high-performance lithium-storage materials.

Science.gov (United States)

Guo, Bingkun; Kong, Qingyu; Zhu, Ying; Mao, Ya; Wang, Zhaoxiang; Wan, Meixiang; Chen, Liquan

2011-12-23

Current lithium-ion battery (LIB) technologies are all based on inorganic electrode materials, though organic materials have been used as electrodes for years. Disadvantages such as limited thermal stability and low specific capacity hinder their applications. On the other hand, the transition metal oxides that provide high lithium-storage capacity by way of electrochemical conversion reaction suffer from poor cycling stability. Here we report a novel high-performance, organic, lithium-storage material, a polypyrrole-cobalt-oxygen (PPy-Co-O) coordination complex, with high lithium-storage capacity and excellent cycling stability. Extended X-ray absorption fine structure and Raman spectroscopy and other physical and electrochemical characterizations demonstrate that this coordination complex can be electrochemically fabricated by cycling PPy-coated Co(3)O(4) between 0.0 V and 3.0 V versus Li(+)/Li. Density functional theory (DFT) calculations indicate that each cobalt atom coordinates with two nitrogen atoms within the PPy-Co coordination layer and the layers are connected with oxygen atoms between them. Coordination weakens the C-H bonds on PPy and makes the complex a novel lithium-storage material with high capacity and high cycling stability. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electricity Storage. Technology Brief

Energy Technology Data Exchange (ETDEWEB)

Simbolotti, G. [Italian National Agency for New Technologies, Energy and Sustainable Economic Development ENEA, Rome (Italy); Kempener, R. [International Renewable Energy Agency IRENA, Bonn (Germany)

2012-04-15

Electricity storage is a key technology for electricity systems with a high share of renewables as it allows electricity to be generated when renewable sources (i.e. wind, sunlight) are available and to be consumed on demand. It is expected that the increasing price of fossil fuels and peak-load electricity and the growing share of renewables will result in electricity storage to grow rapidly and become more cost effective. However, electricity storage is technically challenging because electricity can only be stored after conversion into other forms of energy, and this involves expensive equipment and energy losses. At present, the only commercial storage option is pumped hydro power where surplus electricity (e.g. electricity produced overnight by base-load coal or nuclear power) is used to pump water from a lower to an upper reservoir. The stored energy is then used to produce hydropower during daily high-demand periods. Pumped hydro plants are large-scale storage systems with a typical efficiency between 70% and 80%, which means that a quarter of the energy is lost in the process. Other storage technologies with different characteristics (i.e. storage process and capacity, conversion back to electricity and response to power demand, energy losses and costs) are currently in demonstration or pre-commercial stages and discussed in this brief report: Compressed air energy storage (CAES) systems, Flywheels; Electrical batteries; Supercapacitors; Superconducting magnetic storage; and Thermal energy storage. No single electricity storage technology scores high in all dimensions. The technology of choice often depends on the size of the system, the specific service, the electricity sources and the marginal cost of peak electricity. Pumped hydro currently accounts for 95% of the global storage capacity and still offers a considerable expansion potential but does not suit residential or small-size applications. CAES expansion is limited due to the lack of suitable

Flexible Grouping for Enhanced Energy Utilization Efficiency in Battery Energy Storage Systems

Directory of Open Access Journals (Sweden)

Weiping Diao

2016-06-01

Full Text Available As a critical subsystem in electric vehicles and smart grids, a battery energy storage system plays an essential role in enhancement of reliable operation and system performance. In such applications, a battery energy storage system is required to provide high energy utilization efficiency, as well as reliability. However, capacity inconsistency of batteries affects energy utilization efficiency dramatically; and the situation becomes more severe after hundreds of cycles because battery capacities change randomly due to non-uniform aging. Capacity mismatch can be solved by decomposing a cluster of batteries in series into several low voltage battery packs. This paper introduces a new analysis method to optimize energy utilization efficiency by finding the best number of batteries in a pack, based on capacity distribution, order statistics, central limit theorem, and converter efficiency. Considering both battery energy utilization and power electronics efficiency, it establishes that there is a maximum energy utilization efficiency under a given capacity distribution among a certain number of batteries, which provides a basic analysis for system-level optimization of a battery system throughout its life cycle. Quantitative analysis results based on aging data are illustrated, and a prototype of flexible energy storage systems is built to verify this analysis.

Optimizing areal capacities through understanding the limitations of lithium-ion electrodes

Energy Technology Data Exchange (ETDEWEB)

Gallagher, Kevin G.; Trask, Stephen E.; Bauer, Christoph; Woehrle, Thomas; Lux, Simon; Tschech, Matthias; Polzin, Bryant J.; Ha, Seungbum; Long, Brandon R.; Wu, Qingliu; Lu, Wenquan; Dees, Dennis W.; Jansen, Andrew N.

2016-01-01

Increasing the areal capacity or electrode thickness in lithium ion batteries is one possible means to increase pack level energy density while simultaneously lowering cost. The physics that limit use of high areal capacity as a function of battery power to energy ratio are poorly understood and thus most currently produced automotive lithium ion cells utilize modest loadings to ensure long life over the vehicle battery operation. Here we show electrolyte transport limits the utilization of the positive electrode at critical C-rates during discharge; whereas, a combination of electrolyte transport and polarization lead to lithium plating in the graphite electrode during charge. Experimental measurements are compared with theoretical predictions based on concentrated solution and porous electrode theories. An analytical expression is derived to provide design criteria for long lived operation based on the physical properties of the electrode and electrolyte. Finally, a guideline is proposed that graphite cells should avoid charge current densities near or above 4 mA/cm2 unless additional precautions have been made to avoid deleterious side reaction.

Design of double containment canister cask storage system

International Nuclear Information System (INIS)

Asami, M.; Matsumoto, T.; Oohama, T.; Kuriyama, K.; Kawakami, K.

2004-01-01

Spent fuels discharged from Japanese LWR will be stored as recycled-fuel-resources in interim storage facilities. The concrete cask storage system is one of important forms for the spent fuel interim storage. In Japan, the interim storage facility will be located near the coast, therefore it is important to prevent SCC (Stress Corrosion Cracking) caused by sea salt particles and to assure the containment integrity of the canister which contains spent fuels. KEPCO, NFT and OCL have designed the double containment canister cask storage system that can assure the long-term containment integrity and monitor the containment performance without storage capacity decrease. Major features of the combined canister cask system are shown as follows: This system can survey containment integrity of dual canisters by monitoring the pressure of the gap between canisters. The primary canister has dual lids sealed by welding. The secondary canister has single lid tightened by bolts and sealed by metallic gaskets. The primary canister is contained in the transport cask during transportation, and the gap between the primary canister and the transport cask is filled with He gas. Under storage condition in the concrete cask, the primary canister is contained in the secondary canister, and the gap between these canisters is filled with helium gas. Hence this system can prevent the primary canister to contact sea salt particle in the air and from SCC. Decrease of cooling performance because of the double canister is compensated by fins fitted on the secondary canister surface. Then, this system can prevent the decrease of storage capacity determined by the fuel temperature limit. This system can assure that the primary canister will keep intact for long term storage. Therefore, in the case of pressure down of the gap between canisters, it can be considered that the secondary canister containment is damaged, and the primary canister will be transferred to another secondary canister at the

Present states and views on vault storage systems

International Nuclear Information System (INIS)

Yoshimura, Eiji

2003-01-01

Storage capacity of spent nuclear fuel storage pools in nuclear power station is reaching to a condition near its limit, and under a condition inevitable on delay of the Pu-thermal utilization plan importance on interim storage of the spent nuclear fuels is further rising. In U.S.A., Germany, and so on, a condition incapable of presenting nuclear energy business itself without its intermediate storage is approaching, so in Japan it will also be a key to smoothly promote the nuclear energy business how the interim storage is used and operated. Under such condition, in Japan storage facilities using a system called by 'metal cask' are established at areas of nuclear power stations to begin their operations. As on the system expensive metal containers are used for storage in themselves, it has a demerit of its high cost. On the other hand, on foreign countries, a storing system called by concrete cask, horizontal silo, or vault is occupying its main stream. Here was introduced present states and future views on vault storage system. (G. K)

Hybrid Storage Market Assessment: A JISEA White Paper

Energy Technology Data Exchange (ETDEWEB)

Ericson, Sean J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rose, Eric [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jayaswal, Harshit [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cole, Wesley J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Engel-Cox, Jill [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Logan, Jeffery [National Renewable Energy Laboratory (NREL), Golden, CO (United States); McLaren, Joyce A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Anderson, Katherine H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Arent, Douglas J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Glassmire, John [HOMER Energy, Boulder, CO (United States); Klawiter, Steffi [HOMER Energy, Boulder, CO (United States); Rajasekaran, Dhiwaakar [HOMER Energy, Boulder, CO (United States)

2017-10-09

This white paper evaluates which markets are best suited for battery storage and storage hybrids and reviews regulations and incentives that support or impede the implementation of standalone storage and battery hybrids. The costs of battery storage technologies have dropped in recent years, resulting in a seven-fold increase in installed capacity over the last decade (1). These technologies offer an attractive rate of return in some locations; however, cost and regulatory barriers still limit the market for storage. Hybridizing a battery (combining the battery with a generator) can in some instances reduce total system costs and increase value compared to separate installations. The fast ramping and dispatchability of a battery can complement the generator to provide services that neither battery nor generator could provide alone. Battery hybrids also benefit from some policy incentives and may be better able to meet market and regulatory requirements.

Researchers wrangle petabytes of data storage with NAS, tape

CERN Multimedia

Pariseau, Beth

2007-01-01

"Much is made in the enterprise data storage industry about the performance of disk systems over tape drives, but the managers of one data center that has eached the far limits of capacity say otherwise. Budget and performance demands forced them to build access protocols and data management tools for disk systems from scratch."

Concrete Materials with Ultra-High Damage Resistance and Self- Sensing Capacity for Extended Nuclear Fuel Storage Systems

Energy Technology Data Exchange (ETDEWEB)

Li, Mo [Univ. of California, Irvine, CA (United States); Nakshatrala, Kalyana [Univ. of Houston, TX (United States); William, Kasper [Univ. of Houston, TX (United States); Xi, Yungping [Univ. of Colorado, Boulder, CO (United States)

2017-02-08

The objective of this project is to develop a new class of multifunctional concrete materials (MSCs) for extended spent nuclear fuel (SNF) storage systems, which combine ultra-high damage resistance through strain-hardening behavior with distributed multi-dimensional damage self-sensing capacity. The beauty of multifunctional concrete materials is two-fold: First, it serves as a major material component for the SNF pool, dry cask shielding and foundation pad with greatly improved resistance to cracking, reinforcement corrosion, and other common deterioration mechanisms under service conditions, and prevention from fracture failure under extreme events (e.g. impact, earthquake). This will be achieved by designing multiple levels of protection mechanisms into the material (i.e., ultrahigh ductility that provides thousands of times greater fracture energy than concrete and normal fiber reinforced concrete; intrinsic cracking control, electrochemical properties modification, reduced chemical and radionuclide transport properties, and crack-healing properties). Second, it offers capacity for distributed and direct sensing of cracking, strain, and corrosion wherever the material is located. This will be achieved by establishing the changes in electrical properties due to mechanical and electrochemical stimulus. The project will combine nano-, micro- and composite technologies, computational mechanics, durability characterization, and structural health monitoring methods, to realize new MSCs for very long-term (greater than 120 years) SNF storage systems.

Storage is absolutely necessary to balance supply and demand

International Nuclear Information System (INIS)

Anon.

2009-01-01

Before liberalization, gas storage was built to balance supply and demand (on a seasonal basis), as well as for broader security of supply concerns. With liberalization, companies started to use storage in a more flexible way as they were no longer obliged to prioritize security of supply. The decline in swing production in the North Sea should have triggered an increase in storage capacity. However, in the UK, investment in storage was neglected until too late. The major points of interest in continental Europe are as follows: due to geological constraints, Latvia is the only Baltic state to have underground storage; storage capacity represents 49% of annual Austria demand; Germany has the biggest European storage facility; in Belgium, Bulgaria, Hungary, Poland and Portugal, just one company in each country has all the storage capacity; in Romania, Romgaz has 92% of storage capacity; in the Czech Republic, RWE owns 75% of the storage; in Slovakia, GDF SUEZ and E.ON have most of the capacity; and storage in Ukraine represents a huge opportunity with a capacity of 34 bcm (billion cubic meters). In oil, strategic stocks are a reality and have been used but in gas, strategic stocks do not exist except 5.1 bcm in Italy, 1 bcm in Spain and 1.2 bcm are being built in Hungary. Some possible EU changes could have an impact on the entire European gas market. Just outside EU-27, Ukraine has a form of strategic storage which represents 10% of its suppliers' annual supplies

Optimization of basic parameters of cyclic operation of underground gas storages

Directory of Open Access Journals (Sweden)

Віктор Олександрович Заєць

2015-04-01

Full Text Available The problem of optimization of process parameters of cyclic operation of underground gas storages in gas mode is determined in the article. The target function is defined, expressing necessary capacity of compressor station for gas injection in the storage. Its minimization will find the necessary technological parameters, such as flow and reservoir pressure change over time. Limitations and target function are reduced to a linear form. Solution of problems is made by the simplex method

Structure and oxygen storage capacity of Pr-doped Ce0.26Zr0.74O2 mixed oxides

Institute of Scientific and Technical Information of China (English)

RAN Rui; WENG Duan; WU Xiaodong; FAN Jun; WANG Lei; WU Xiaodi

2011-01-01

Binary Ce-Zr (CZ),Pr-Zr (PZ) and ternary Ce-Zr-Pr (CZP) mixed oxides were prepared by an ammonia-aided co-precipitation method,and were aged in a steam/air flow at 1050 ℃.X-my diffraction (XRD),Raman spectra,X-photon spectra (XPS) and CO temperature programmed reduction (TPR) were carried out to characterize the micro-structure and reducibility of catalysts.The oxygen storage capacity (OSC) was evaluated with CO serving as probe gas.The results showed that a pseudo cubic structure was formed for the Zr-rich ceria-zirconia mixed oxides with Pr doping.The insertion of Pr prevented the phase segregation of the mixed oxides during the hydrothermal ageing.The Pr doped samples showed better redox performances in comparison with CZ,and the sample doped with 5 wt.％ Pr showed the most remarkably promoted dynamic oxygen storage capacity.This phenomenon was closely related to both the reducibility and oxygen mobility of the mixed oxides.The introduction of praseodymium into ceria-zirconia could accelerate the oxygen migration by increasing the amount of oxygen vacancies,although it was difficult for Pr3+ ions themselves to participate in the oxygen exchange process.

Fast storage of nuclear quadrupole resonance signals

International Nuclear Information System (INIS)

Anferov, V.P.; Molchanov, S.V.; Levchun, O.D.

1988-01-01

Fast multichannel storage of nuclear quadrupole resonance (NQR) signals is described. Analog-to-digital converter, arithmetic-logical unit, internal memory device (IMD) selection-storage unit and control unit are the storage main units. The storage is based on 43 microcircuits and provides for record and storage of NQR-signals at the contributed operation with Mera-60 microcomputer. Time of analog-to-digital conversion and signal recording into IMD is ∼ 1 mks. Capacity of analog-to-digital converter constitutes 8-10 bits. IMD capacity is 4 K bitsx16. Number of storage channels is 4

The frontal eye fields limit the capacity of visual short-term memory in rhesus monkeys.

Directory of Open Access Journals (Sweden)

Kyoung-Min Lee

Full Text Available The frontal eye fields (FEF in rhesus monkeys have been implicated in visual short-term memory (VSTM as well as control of visual attention. Here we examined the importance of the area in the VSTM capacity and the relationship between VSTM and attention, using the chemical inactivation technique and multi-target saccade tasks with or without the need of target-location memory. During FEF inactivation, serial saccades to targets defined by color contrast were unaffected, but saccades relying on short-term memory were impaired when the target count was at the capacity limit of VSTM. The memory impairment was specific to the FEF-coded retinotopic locations, and subject to competition among targets distributed across visual fields. These results together suggest that the FEF plays a crucial role during the entry of information into VSTM, by enabling attention deployment on targets to be remembered. In this view, the memory capacity results from the limited availability of attentional resources provided by FEF: The FEF can concurrently maintain only a limited number of activations to register the targets into memory. When lesions render part of the area unavailable for activation, the number would decrease, further reducing the capacity of VSTM.

Modular dry storage of spent fuel

International Nuclear Information System (INIS)

Baxter, J.W.

1982-01-01

Long term uncertainties in US spent fuel reprocessing and storage policies and programs are forcing the electric utilities to consider means of storing spent fuel at the reactor site in increasing quantitities and for protracted periods. Utilities have taken initial steps in increasing storage capacity. Existing wet storage pools have in many cases been reracked to optimize their capacity for storing spent fuel assemblies

Which way for Europe's gas storage market?

International Nuclear Information System (INIS)

Hureau, Geoffroy; Cornot-Gandolphe, Sylvie

2013-06-01

This slide show presents in a first part the 2013 Situation of the European gas storage market (Capacity, Gas Demand vs. Gas Storage, Spreads and Volatility, LNG effect, Storage Price, Utilization of Storage Facilities, Security of supply). The future of European Gas Demand and Supply are presented in a second part (Demand and Supply Factors, Market Liberalization, Estimates of European UGS Needs by 2030, Planned Working Gas Capacities in Europe)

X-ray nanoprobes and diffraction-limited storage rings: opportunities and challenges of fluorescence tomography of biological specimens

Energy Technology Data Exchange (ETDEWEB)

Jonge, Martin D. de, E-mail: martin.dejonge@synchrotron.org.au [Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168 (Australia); Ryan, Christopher G. [CSIRO Earth Science and Research Engineering, Clayton, Victoria 3168 (Australia); Jacobsen, Chris J. [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Department of Physics, Chemistry of Life Processes Institute, Northwestern University, 2170 Campus Drive, Evanston, IL 60208 (United States); Chemistry of Life Processes Institute, Northwestern University, 2170 Campus Drive, Evanston, IL 60208 (United States)

2014-08-27

Nanoscale X-ray scanning microscopes, or X-ray nanoprobes, will benefit greatly from diffraction-limited storage rings. Here the requirements for nanoscale fluorescence tomography are explored to gain insight into the scientific opportunities and technical challenges that such sources offer. X-ray nanoprobes require coherent illumination to achieve optic-limited resolution, and so will benefit directly from diffraction-limited storage rings. Here, the example of high-resolution X-ray fluorescence tomography is focused on as one of the most voracious demanders of coherent photons, since the detected signal is only a small fraction of the incident flux. Alternative schemes are considered for beam delivery, sample scanning and detectors. One must consider as well the steps before and after the X-ray experiment: sample preparation and examination conditions, and analysis complexity due to minimum dose requirements and self-absorption. By understanding the requirements and opportunities for nanoscale fluorescence tomography, one gains insight into the R&D challenges in optics and instrumentation needed to fully exploit the source advances that diffraction-limited storage rings offer.

Templated assembly of photoswitches significantly increases the energy-storage capacity of solar thermal fuels.

Science.gov (United States)

Kucharski, Timothy J; Ferralis, Nicola; Kolpak, Alexie M; Zheng, Jennie O; Nocera, Daniel G; Grossman, Jeffrey C

2014-05-01

Large-scale utilization of solar-energy resources will require considerable advances in energy-storage technologies to meet ever-increasing global energy demands. Other than liquid fuels, existing energy-storage materials do not provide the requisite combination of high energy density, high stability, easy handling, transportability and low cost. New hybrid solar thermal fuels, composed of photoswitchable molecules on rigid, low-mass nanostructures, transcend the physical limitations of molecular solar thermal fuels by introducing local sterically constrained environments in which interactions between chromophores can be tuned. We demonstrate this principle of a hybrid solar thermal fuel using azobenzene-functionalized carbon nanotubes. We show that, on composite bundling, the amount of energy stored per azobenzene more than doubles from 58 to 120 kJ mol(-1), and the material also maintains robust cyclability and stability. Our results demonstrate that solar thermal fuels composed of molecule-nanostructure hybrids can exhibit significantly enhanced energy-storage capabilities through the generation of template-enforced steric strain.

Experimental Research and Control Strategy of Pumped Storage Units Dispatching in the Taiwan Power System Considering Transmission Line Limits

Directory of Open Access Journals (Sweden)

Ming-Tse Kuo

2013-07-01

Full Text Available Taiwan’s power system is isolated and not supported by other interconnected systems. Consequently, the system frequency immediately reflects changes in the system loads. Pumped storage units are crucial for controlling power frequency. These units provide main or auxiliary capacities, reducing the allocation of frequency-regulating reserve (FRR and further reducing generation costs in system operations. Taiwan’s Longmen Nuclear Power Plant is set to be converted for commercial operations, which will significantly alter the spinning reserves in the power system. Thus, this study proposes a safe and economic pumped storage unit dispatch strategy. This strategy is used to determine the optimal FRR capacity and 1-min recovery frequency in a generator failure occurrence at the Longmen Power Plant. In addition, this study considered transmission capacity constraints and conducted power flow analysis of the power systems in Northern, Central, and Southern Taiwan. The results indicated that, in the event of a failure at Longmen Power Plant, the proposed strategy can not only recover the system frequency to an acceptable range to prevent underfrequency load-shedding, but can also mitigate transmission line overloading.

Criticality impacts on LWR fuel storage efficiency

International Nuclear Information System (INIS)

Napolitano, D.

1992-01-01

This presentation discusses the criticality impacts throughout storage of fuel onsite including new fuel storage, spent fuel storage, consolidation, and dry storage. The general principles for criticality safety are also be discussed. There is first an introduction which explains today's situation for criticality safety concerns. This is followed by a discussion of criticality safety Regulatory Guides, safety limits and fundamental principles. Design objectives for criticality safety in the 1990's include higher burnups, longer cycles, and higher enrichments which impact the criticality safety design. Criticality safety for new fuel storage, spent fuel storage, fuel consolidation, and dry storage are followed by conclusions. Today's situation is one in which the US does not reprocess, and does not have an operating MRS facility or repository. High density fuel storage rack designs of the 1980s, are filling up. Dry cask storage systems for spent fuel storage are being utilized. Enrichments continue to increase PWR fuel assemblies with enrichments of 4.5 to 5.0 weight percent U-235 and BWR fuel assemblies with enrichments of 3.25 to 3.5 weight percent U-235 are common. Criticality concerns affect the capacity and the economics of light water reactor (LWR) fuel storage arrays by dictating the spacing of fuel assemblies in a storage system, or the use of poisons or exotic materials in the storage system design

Considerations on the need for electricity storage requirements: Power versus energy

International Nuclear Information System (INIS)

Belderbos, Andreas; Virag, Ana; D’haeseleer, William; Delarue, Erik

2017-01-01

Highlights: • General storage principles are analyzed. • Storage units have different limitations (power versus energy). • Storage power and energy are required, dependent on residual profile. • Relationship between residual profile and optimal storage portfolio is derived. • Broadly applicable rules regarding optimal storage investments are presented. - Abstract: Different storage technologies enable an increasing share of variable renewable generation in the electricity system by reducing the temporal mismatch between generation and demand. Two storage ratings are essential to time-shift delivery of electricity to loads: electric power, or instantaneous electricity flow [W], and electric energy, or power integrated over time [Wh]. An optimal storage portfolio is likely composed of multiple technologies, each having specific power and energy ratings. This paper derives and explains the link between the shape of the time-varying demand and generation profiles and the amount of desirably installed storage capacity, both energy and power. An analysis is performed for individual storage technologies first, showing a link between the necessary power and energy capacity and the demand and generation profile. Then combinations of storage technologies are analyzed to reveal their mutual interaction in a storage portfolio. Results show an increase in desirability for storage technologies with low cost power ratings when the mismatch between generation and demand occurs in daily to weekly cycles. Storage technologies with low cost energy ratings are preferred when this mismatch occurs in monthly to seasonal cycles. The findings of this work can help energy system planners and policy makers to explain results from generation expansion planning studies and to isolate the storage benefits accountable to temporal arbitrage in broader electricity storage studies.

Impact of sea-level rise on Everglades carbon storage capacity in the Holocene

Science.gov (United States)

Jones, M.; Bernhardt, C. E.; Wingard, G. L. L.; Keller, K.; Stackhouse, B.; Landacre, B.

2017-12-01

storage capacity of the Florida Everglades could decrease significantly if the freshwater Everglades accretion rate cannot outpace SLR. Further, the expansion and persistence of high-accumulating Rhizophora peat is limited by elevated SLR, impacting coastline stability and wildlife habitat.

Depth of cinder deposits and water-storage capacity at Cinder Lake, Coconino County, Arizona

Science.gov (United States)

Macy, Jamie P.; Amoroso, Lee; Kennedy, Jeff; Unema, Joel

2012-01-01

The 2010 Schultz fire northeast of Flagstaff, Arizona, burned more than 15,000 acres on the east side of San Francisco Mountain from June 20 to July 3. As a result, several drainages in the burn area are now more susceptible to increased frequency and volume of runoff, and downstream areas are more susceptible to flooding. Resultant flooding in areas downgradient of the burn has resulted in extensive damage to private lands and residences, municipal water lines, and roads. Coconino County, which encompasses Flagstaff, has responded by deepening and expanding a system of roadside ditches to move flood water away from communities and into an area of open U.S. Forest Service lands, known as Cinder Lake, where rapid infiltration can occur. Water that has been recently channeled into the Cinder Lake area has infiltrated into the volcanic cinders and could eventually migrate to the deep regional groundwater-flow system that underlies the area. How much water can potentially be diverted into Cinder Lake is unknown, and Coconino County is interested in determining how much storage is available. The U.S. Geological Survey conducted geophysical surveys and drilled four boreholes to determine the depth of the cinder beds and their potential for water storage capacity. Results from the geophysical surveys and boreholes indicate that interbedded cinders and alluvial deposits are underlain by basalt at about 30 feet below land surface. An average total porosity for the upper 30 feet of deposits was calculated at 43 percent for an area of 300 acres surrounding the boreholes, which yields a total potential subsurface storage for Cinder Lake of about 4,000 acre-feet. Ongoing monitoring of storage change in the Cinder Lake area was initiated using a network of gravity stations.

The recycling of domestic waste water. A study of the factors influencing the storage capacity and the simulation of the usage patterns

Energy Technology Data Exchange (ETDEWEB)

Fewkes, A; Ferris, S A

1982-01-01

The flushing of toilets with recycled domestic waste water makes a significant saving in the use of potable water. The size of the storage tank is a critical factor in the design of such a system; the inputs to the storage, which are random, are influenced by the size of family and individual washing and bathing habits. The demand from the storage tank is random in time but the volume is constant at each occurrence. A method of generating these waste water time series, with their inherent stochastic nature, is described. These simulated event patterns are then used to investigate the operation of a single-tank waste water storage system. The computer model determines the percentage of water conserved for several combinations of storage capacity and family size: the effect of changes in design parameters and operating conditions on the system performance is also assessed.

Estimating restorable wetland water storage at landscape scales

Science.gov (United States)

Jones, Charles Nathan; Evenson, Grey R.; McLaughlin, Daniel L.; Vanderhoof, Melanie; Lang, Megan W.; McCarty, Greg W.; Golden, Heather E.; Lane, Charles R.; Alexander, Laurie C.

2018-01-01

Globally, hydrologic modifications such as ditching and subsurface drainage have significantly reduced wetland water storage capacity (i.e., volume of surface water a wetland can retain) and consequent wetland functions. While wetland area has been well documented across many landscapes and used to guide restoration efforts, few studies have directly quantified the associated wetland storage capacity. Here, we present a novel raster-based approach to quantify both contemporary and potential (i.e., restorable) storage capacities of individual depressional basins across landscapes. We demonstrate the utility of this method by applying it to the Delmarva Peninsula, a region punctuated by both depressional wetlands and drainage ditches. Across the entire peninsula, we estimated that restoration (i.e., plugging ditches) could increase storage capacity by 80%. Focusing on an individual watershed, we found that over 59% of restorable storage capacity occurs within 20 m of the drainage network, and that 93% occurs within 1 m elevation of the drainage network. Our demonstration highlights widespread ditching in this landscape, spatial patterns of both contemporary and potential storage capacities, and clear opportunities for hydrologic restoration. In Delmarva and more broadly, our novel approach can inform targeted landscape-scale conservation and restoration efforts to optimize hydrologically mediated wetland functions.

Archival storage solutions for PACS

Science.gov (United States)

Chunn, Timothy

1997-05-01

While they are many, one of the inhibitors to the wide spread diffusion of PACS systems has been robust, cost effective digital archive storage solutions. Moreover, an automated Nearline solution is key to a central, sharable data repository, enabling many applications such as PACS, telemedicine and teleradiology, and information warehousing and data mining for research such as patient outcome analysis. Selecting the right solution depends on a number of factors: capacity requirements, write and retrieval performance requirements, scaleability in capacity and performance, configuration architecture and flexibility, subsystem availability and reliability, security requirements, system cost, achievable benefits and cost savings, investment protection, strategic fit and more.This paper addresses many of these issues. It compares and positions optical disk and magnetic tape technologies, which are the predominant archive mediums today. Price and performance comparisons will be made at different archive capacities, plus the effect of file size on storage system throughput will be analyzed. The concept of automated migration of images from high performance, high cost storage devices to high capacity, low cost storage devices will be introduced as a viable way to minimize overall storage costs for an archive. The concept of access density will also be introduced and applied to the selection of the most cost effective archive solution.

Proceedings of the 1979 workshop on beam current limitations in storage rings, July 16-27, 1979

International Nuclear Information System (INIS)

Pellegrini, C.

1979-01-01

The Workshop on Beam Current Limitations in Storage Rings was held at Brookhaven National Laboratory from July 16 to 27, 1979. The purpose of this Workshop was to discuss the physical mechanisms limiting the beam current or current density in accelerators or storage rings. Many of these machines are now being built or planned for a variety of applications, such as colliding beam experiments, synchrotron light production, heavy ion beams. This diversity was reflected in the Workshop and in the papers which have been contributed to these Proceedings. The twenty-one papers from the workshop were incorporated individually in the data base

High levels of time contraction in young children in dual tasks are related to their limited attention capacities.

Science.gov (United States)

Hallez, Quentin; Droit-Volet, Sylvie

2017-09-01

Numerous studies have shown that durations are judged shorter in a dual-task condition than in a simple-task condition. The resource-based theory of time perception suggests that this is due to the processing of temporal information, which is a demanding cognitive task that consumes limited attention resources. Our study investigated whether this time contraction in a dual-task condition is greater in younger children and, if so, whether this is specifically related to their limited attention capacities. Children aged 5-7years were given a temporal reproduction task in a simple-task condition and a dual-task condition. In addition, different neuropsychological tests were used to assess not only their attention capacities but also their capacities in terms of working memory and information processing speed. The results showed a shortening of perceived time in the dual task compared with the simple task, and this increased as age decreased. The extent of this shortening effect was directly linked to younger children's limited attentional capacities; the lower their attentional capacities, the greater the time contraction. This study demonstrated that children's errors in time judgments are linked to their cognitive capacities rather than to capacities that are specific to time. Copyright © 2017 Elsevier Inc. All rights reserved.

Prospects for hydrogen storage in graphene.

Science.gov (United States)

Tozzini, Valentina; Pellegrini, Vittorio

2013-01-07

Hydrogen-based fuel cells are promising solutions for the efficient and clean delivery of electricity. Since hydrogen is an energy carrier, a key step for the development of a reliable hydrogen-based technology requires solving the issue of storage and transport of hydrogen. Several proposals based on the design of advanced materials such as metal hydrides and carbon structures have been made to overcome the limitations of the conventional solution of compressing or liquefying hydrogen in tanks. Nevertheless none of these systems are currently offering the required performances in terms of hydrogen storage capacity and control of adsorption/desorption processes. Therefore the problem of hydrogen storage remains so far unsolved and it continues to represent a significant bottleneck to the advancement and proliferation of fuel cell and hydrogen technologies. Recently, however, several studies on graphene, the one-atom-thick membrane of carbon atoms packed in a honeycomb lattice, have highlighted the potentialities of this material for hydrogen storage and raise new hopes for the development of an efficient solid-state hydrogen storage device. Here we review on-going efforts and studies on functionalized and nanostructured graphene for hydrogen storage and suggest possible developments for efficient storage/release of hydrogen under ambient conditions.

International long-term interim storage for spent fuel. An independent storage service investor model

International Nuclear Information System (INIS)

Leister, P.

1999-01-01

Thinking globally the obvious world-wide demands for large storage capacities for spent fuel within the next decades and the newly arising demands for long-term interim storage of spent fuel urges to respond by international interim storage facilities of high capacity. Low cost storage can be achieved only by arranging the storage facility underground in a suitable host rock formation and by selecting the geographical are by an international competition under those countries, who are willing to offer their land. The investor and operator of an international storage facility selected and realised by a competition on the free market as well as the country where the storage is built are both bound by two different kinds of contacts. The main contract is between the offering country/region and the independent operator. The independent operator has in addition a series of contracts with various utilities, which are interested to have their spent fuel stored for a longer period

76 FR 283 - International Fisheries; Pacific Tuna Fisheries; Vessel Capacity Limit in the Purse Seine Fishery...

Science.gov (United States)

2011-01-04

... of implementing a capacity management regime, the United States chose to further limit its fleet... Inter-American Tropical Tuna Commission (IATTC) Resolution on the Capacity of the Tuna Fleet Operating.... industry consistent with the IATTC management framework. DATES: These regulations become effective on...

Can ionophobic nanopores enhance the energy storage capacity of electric-double-layer capacitors containing nonaqueous electrolytes?

International Nuclear Information System (INIS)

Lian, Cheng; University of California, Riverside, CA; Liu, Honglai; Henderson, Douglas; Wu, Jianzhong

2016-01-01

The ionophobicity effect of nanoporous electrodes on the capacitance and the energy storage capacity of nonaqueous-electrolyte supercapacitors is studied by means of the classical density functional theory (DFT). It has been hypothesized that ionophobic nanopores may create obstacles in charging, but they store energy much more efficiently than ionophilic pores. In this paper, we find that, for both ionic liquids and organic electrolytes, an ionophobic pore exhibits a charging behavior different from that of an ionophilic pore, and that the capacitance–voltage curve changes from a bell shape to a two-hump camel shape when the pore ionophobicity increases. For electric-double-layer capacitors containing organic electrolytes, an increase in the ionophobicity of the nanopores leads to a higher capacity for energy storage. Without taking into account the effects of background screening, the DFT predicts that an ionophobic pore containing an ionic liquid does not enhance the supercapacitor performance within the practical voltage ranges. However, by using an effective dielectric constant to account for ion polarizability, the DFT predicts that, like an organic electrolyte, an ionophobic pore with an ionic liquid is also able to increase the energy stored when the electrode voltage is beyond a certain value. We find that the critical voltage for an enhanced capacitance in an ionic liquid is larger than that in an organic electrolyte. Finally, our theoretical predictions provide further understanding of how chemical modification of porous electrodes affects the performance of supercapacitors.

Carbon storage capacity of semi-arid grassland soils and sequestration potentials in northern China.

Science.gov (United States)

Wiesmeier, Martin; Munro, Sam; Barthold, Frauke; Steffens, Markus; Schad, Peter; Kögel-Knabner, Ingrid

2015-10-01

Organic carbon (OC) sequestration in degraded semi-arid environments by improved soil management is assumed to contribute substantially to climate change mitigation. However, information about the soil organic carbon (SOC) sequestration potential in steppe soils and their current saturation status remains unknown. In this study, we estimated the OC storage capacity of semi-arid grassland soils on the basis of remote, natural steppe fragments in northern China. Based on the maximum OC saturation of silt and clay particles soils (grazing land, arable land, eroded areas) were estimated. The analysis of natural grassland soils revealed a strong linear regression between the proportion of the fine fraction and its OC content, confirming the importance of silt and clay particles for OC stabilization in steppe soils. This relationship was similar to derived regressions in temperate and tropical soils but on a lower level, probably due to a lower C input and different clay mineralogy. In relation to the estimated OC storage capacity, degraded steppe soils showed a high OC saturation of 78-85% despite massive SOC losses due to unsustainable land use. As a result, the potential of degraded grassland soils to sequester additional OC was generally low. This can be related to a relatively high contribution of labile SOC, which is preferentially lost in the course of soil degradation. Moreover, wind erosion leads to substantial loss of silt and clay particles and consequently results in a direct loss of the ability to stabilize additional OC. Our findings indicate that the SOC loss in semi-arid environments induced by intensive land use is largely irreversible. Observed SOC increases after improved land management mainly result in an accumulation of labile SOC prone to land use/climate changes and therefore cannot be regarded as contribution to long-term OC sequestration. © 2015 John Wiley & Sons Ltd.

Mobility and Congestion in Dynamical Multilayer Networks with Finite Storage Capacity

Science.gov (United States)

Manfredi, S.; Di Tucci, E.; Latora, V.

2018-02-01

Multilayer networks describe well many real interconnected communication and transportation systems, ranging from computer networks to multimodal mobility infrastructures. Here, we introduce a model in which the nodes have a limited capacity of storing and processing the agents moving over a multilayer network, and their congestions trigger temporary faults which, in turn, dynamically affect the routing of agents seeking for uncongested paths. The study of the network performance under different layer velocities and node maximum capacities reveals the existence of delicate trade-offs between the number of served agents and their time to travel to destination. We provide analytical estimates of the optimal buffer size at which the travel time is minimum and of its dependence on the velocity and number of links at the different layers. Phenomena reminiscent of the slower is faster effect and of the Braess' paradox are observed in our dynamical multilayer setup.

Hydrogen isotope storage in zircaloy scrap

Energy Technology Data Exchange (ETDEWEB)

Lee, H. S.; Kuk, I. H.; Chung, H.; Paek, S. W.; Kang, H. S

1999-08-01

8 MCi of tritium a year will be produced after wolsong TRF is in operation. The metal hydride form is one of useful tritium storage. The metals in use for metal hydride are uranium, titanium, etc., however uranium is limited to use by regulation, and titanium is relatively costly. Both metals are not produced in country but whole amount is imported. On the other hand 2,000kg of zircaloy scrap is produced by CANDU nuclear fuel fabrication process, which is also useful for hydrogen storage. The purpose of this study is to evaluation of hydrogen absorption capacity for zircaloy scrap that is produced as waste by CANDU nuclear fuel fabrication process. The sample evacuated for an hour at 1000 deg C. The strip showed higher capacity : 0.7 at 25 deg C, 2.0 at 200 deg C, 2.0 at 200 deg C, 2.0 at 400 deg C, respectively. The H/M values for commercial zircaloy sponge were 2.0 at 25 deg C and 2.0 at 400 deg C.

Hydrogen isotope storage in zircaloy scrap

International Nuclear Information System (INIS)

Lee, H. S.; Kuk, I. H.; Chung, H.; Paek, S. W.; Kang, H. S.

1999-08-01

8 MCi of tritium a year will be produced after wolsong TRF is in operation. The metal hydride form is one of useful tritium storage. The metals in use for metal hydride are uranium, titanium, etc., however uranium is limited to use by regulation, and titanium is relatively costly. Both metals are not produced in country but whole amount is imported. On the other hand 2,000kg of zircaloy scrap is produced by CANDU nuclear fuel fabrication process, which is also useful for hydrogen storage. The purpose of this study is to evaluation of hydrogen absorption capacity for zircaloy scrap that is produced as waste by CANDU nuclear fuel fabrication process. The sample evacuated for an hour at 1000 deg C. The strip showed higher capacity : 0.7 at 25 deg C, 2.0 at 200 deg C, 2.0 at 200 deg C, 2.0 at 400 deg C, respectively. The H/M values for commercial zircaloy sponge were 2.0 at 25 deg C and 2.0 at 400 deg C

On the Secrecy Capacity of the Multiple-Antenna Wiretap Channel with Limited CSI Feedback

KAUST Repository

Hyadi, Amal; Rezki, Zouheir; Alouini, Mohamed-Slim

2015-01-01

We study the ergodic secrecy capacity of a block fading wiretap channel when there are multiple antennas at the transmitter, the legitimate receiver and the eavesdropper. We consider that the receivers are aware of their respective channel matrices while the transmitter is only provided by a B-bits feedback of the main channel state information. The feedback bits are sent by the legitimate receiver, at the beginning of each fading block, over an error free public link with limited capacity. Assuming an average transmit power constraint, we provide an upper and a lower bounds on the ergodic secrecy capacity. Then, we present a framework to design the optimal codebooks for feedback and transmission. In addition, we show that the proposed lower and upper bounds coincide asymptotically as the capacity of the feedback link becomes large; hence, fully characterizing the secrecy capacity in this case.

On the Secrecy Capacity of the Multiple-Antenna Wiretap Channel with Limited CSI Feedback

KAUST Repository

Hyadi, Amal

2015-12-01

We study the ergodic secrecy capacity of a block fading wiretap channel when there are multiple antennas at the transmitter, the legitimate receiver and the eavesdropper. We consider that the receivers are aware of their respective channel matrices while the transmitter is only provided by a B-bits feedback of the main channel state information. The feedback bits are sent by the legitimate receiver, at the beginning of each fading block, over an error free public link with limited capacity. Assuming an average transmit power constraint, we provide an upper and a lower bounds on the ergodic secrecy capacity. Then, we present a framework to design the optimal codebooks for feedback and transmission. In addition, we show that the proposed lower and upper bounds coincide asymptotically as the capacity of the feedback link becomes large; hence, fully characterizing the secrecy capacity in this case.

Spent fuel storage requirements, 1991--2040

International Nuclear Information System (INIS)

1991-12-01

Historical inventories of spent fuel are combined with US Department of Energy (DOE) projections of future discharges from commercial nuclear reactors in the United States to provide estimates of spent fuel storage requirements over the next 50 years, through the year 2040. The needs for storage capacity beyond that presently available in the pools are estimated. These estimates incorporate the maximum capacities within current and planned in-pool storage facilities and any planned transshipments of fuel to other reactors or facilities. Existing and future dry storage facilities are also discussed. Historical data through December 1990 are derived from the 1991 Form RW-859 data survey of nuclear utilities. Projected discharges through the end of reactor life are based on DOE estimates of future nuclear capacity, generation, and spent fuel discharges

Lithium decoration of three dimensional boron-doped graphene frameworks for high-capacity hydrogen storage

International Nuclear Information System (INIS)

Wang, Yunhui; Meng, Zhaoshun; Liu, Yuzhen; You, Dongsen; Wu, Kai; Lv, Jinchao; Wang, Xuezheng; Deng, Kaiming; Lu, Ruifeng; Rao, Dewei

2015-01-01

Based on density functional theory and the first principles molecular dynamics simulations, a three-dimensional B-doped graphene-interconnected framework has been constructed that shows good thermal stability even after metal loading. The average binding energy of adsorbed Li atoms on the proposed material (2.64 eV) is considerably larger than the cohesive energy per atom of bulk Li metal (1.60 eV). This value is ideal for atomically dispersed Li doping in experiments. From grand canonical Monte Carlo simulations, high hydrogen storage capacities of 5.9 wt% and 52.6 g/L in the Li-decorated material are attained at 298 K and 100 bars

Low-crystallinity molybdenum sulfide nanosheets assembled on carbon nanotubes for long-life lithium storage: Unusual electrochemical behaviors and ascending capacities

Energy Technology Data Exchange (ETDEWEB)

Li, Xiaodan, E-mail: xiaodan_li@yeah.net [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Wu, Gaoxiang, E-mail: wgxjimmy@126.com [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Chen, Jiewei, E-mail: kzscjw@126.com [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Li, Meicheng, E-mail: mcli@ncepu.edu.cn [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Chongqing Materials Research Institute, Chongqing 400707 (China); Li, Wei, E-mail: wei.li@inl.int [International Iberian Nanotechnology Laboratory (INL), Braga 4715-330 (Portugal); Wang, Tianyue, E-mail: 1355796015@qq.com [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Jiang, Bing, E-mail: BingJiang@ncepu.edu.cn [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); He, Yue, E-mail: 947667748@qq.com [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China ElectricPower University, Beijing, 102206 (China); Mai, Liqiang, E-mail: mlq518@whut.edu.cn [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

2017-01-15

Highlights: • Low-crystallinity molybdenum sulfide coated on carbon nanotubes were synthesized. • This anode material has unusual electrochemical behaviors compared to typical MoS{sub 2}. • It exhibits noticable ascending trends in capacity and superior rate performance. • The ascending performance can effectively extend the circulation life of batteries. - Abstract: Low-crystallinity molybdenum sulfide (LCMS, Mo:S = 1:2.75) nanosheets synthesized by a facile and low temperature solvothermal method is now reported. The as-prepared LCMS anode material is composited of MoS{sub 2} layers mixed with amorphous MoS{sub 3}, which leads to an unusual electrochemical process for lithium storage compared to typical MoS{sub 2} anode. The existence of MoS{sub 3} and Mo (VI) provide strong adsorption and binding sites for polar polysulphides, which compels abundant sulfur to turn into new-formed MoS{sub 3} rather than diffuse into electrolyte. To fully utilize this novel electrochemical process, LCMS is decorated on carbon nanotubes, obtaining well-dispersed CNTs@LCMS. As electrode material for lithium storage, CNTs@LCMS exhibits a noticable ascending trend in capacity from 820 mA h g{sup −1} to 1350 mA h g{sup −1} at 100 mA g{sup −1} during 130 cycles. The persistent ascending capacity is ascribed to the increasing lithium storage caused by new-formed MoS{sub 3}, combined with the reduced volume change benifiting from well-dispersed CNTs@LCMS. Furthermore, the ascending performance is proved to be able to effectively extend the circulation life (up to 200%) for lithium-ion batteries by mathematical modeling and calculation. Accordingly, the CNTs@LCMS composite is a promising anode material for long-life lithium-ion batteries.

Electron-beam irradiation effects on phytochemical constituents and antioxidant capacity of pecan kernels [ Carya illinoinensis (Wangenh.) K. Koch] during storage.

Science.gov (United States)

Villarreal-Lozoya, Jose E; Lombardini, Leonardo; Cisneros-Zevallos, Luis

2009-11-25

Pecans kernels (Kanza and Desirable cultivars) were irradiated with 0, 1.5, and 3.0 kGy using electron-beam (E-beam) irradiation and stored under accelerated conditions [40 degrees C and 55-60% relative humidity (RH)] for 134 days. Antioxidant capacity (AC) using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays, phenolic (TP) and condensed tannin (CT) content, high-performance liquid chromatography (HPLC) phenolic profile, tocopherol content, peroxide value (PV), and fatty acid profiles were determined during storage. Irradiation decreased TP and CT with no major detrimental effects in AC. Phenolic profiles after hydrolysis were similar among treatments (e.g., gallic and ellagic acid, catechin, and epicatechin). Tocopherol content decreased with irradiation (>21 days), and PV increased at later stages (>55 days), with no change in fatty acid composition among treatments. Color lightness decreased, and a reddish brown hue developed during storage. A proposed mechanism of kernel oxidation is presented, describing the events taking place. In general, E-beam irradiation had slight effects on phytochemical constituents and could be considered a potential tool for pecan kernel decontamination.

On the secrecy capacity of the broadcast wiretap channel with limited CSI feedback

KAUST Repository

Hyadi, Amal

2016-10-27

In this paper, we investigate the problem of secure broadcasting over block-fading channels with limited channel knowledge at the transmitter. More particularly, we analyze the effect of having imperfect channel state information (CSI) via a finite rate feedback on the throughput of a broadcast channel where the transmission is intended for multiple legitimate receivers in the presence of an eavesdropper. First, we partially characterize the ergodic secrecy capacity of the system when the source broadcasts the same information to all the receivers, i.e., common message transmission. Then, we look at the independent messages case, where the transmitter broadcasts multiple independent messages to the legitimate receivers. For this case, we present lower and upper bounds on the ergodic secrecy sum-capacity. In both scenarios, we show that the proposed lower and upper bounds coincide asymptotically as the capacity of the feedback links becomes large, hence, fully characterizing the secrecy capacity in this case.

On the secrecy capacity of the broadcast wiretap channel with limited CSI feedback

KAUST Repository

Hyadi, Amal; Rezki, Zouheir; Alouini, Mohamed-Slim

2016-01-01

In this paper, we investigate the problem of secure broadcasting over block-fading channels with limited channel knowledge at the transmitter. More particularly, we analyze the effect of having imperfect channel state information (CSI) via a finite rate feedback on the throughput of a broadcast channel where the transmission is intended for multiple legitimate receivers in the presence of an eavesdropper. First, we partially characterize the ergodic secrecy capacity of the system when the source broadcasts the same information to all the receivers, i.e., common message transmission. Then, we look at the independent messages case, where the transmitter broadcasts multiple independent messages to the legitimate receivers. For this case, we present lower and upper bounds on the ergodic secrecy sum-capacity. In both scenarios, we show that the proposed lower and upper bounds coincide asymptotically as the capacity of the feedback links becomes large, hence, fully characterizing the secrecy capacity in this case.

Hydropower generation and storage, transmission constraints and market power

International Nuclear Information System (INIS)

Johnsen, T.A.

2001-01-01

We study hydropower generation and storage in the presence of uncertainty about future inflows, market power and limited transmission capacity to neighboring regions. Within our simple two-period model, market power leads to too little storage. The monopolist finds it profitable to produce more than the competitive amount in the first period and thereby stores little water in the first of two periods in order to become import constrained in the second period. In addition, little storage reduces the probability of becoming export constrained in the second period, even if the second period exhibits large inflow. Empirical findings for an area in the western part of Norway with only hydropower and high ownership concentration at the supply side, fit well to our theoretical model. We apply a numerical model to examine various policies to reduce the inefficiencies created by the local monopoly. Transmission investments have two effects. First, the export possibilities in the first period increase. More export leads to lower storage in the first period. Second, larger import capacity reduces the market power problem in the second period. The two opposite effects of transmission investments in a case with market power may be unique to hydropower systems. Introducing financial transmission rights enhance the market power of the monopolist in our model. Price caps in both or in the second period only, reduce the strategic value of water storage. (Author)

Reservoir operations under climate change: Storage capacity options to mitigate risk

Science.gov (United States)

Ehsani, Nima; Vörösmarty, Charles J.; Fekete, Balázs M.; Stakhiv, Eugene Z.

2017-12-01

Observed changes in precipitation patterns, rising surface temperature, increases in frequency and intensity of floods and droughts, widespread melting of ice, and reduced snow cover are some of the documented hydrologic changes associated with global climate change. Climate change is therefore expected to affect the water supply-demand balance in the Northeast United States and challenge existing water management strategies. The hydrological implications of future climate will affect the design capacity and operating characteristics of dams. The vulnerability of water resources systems to floods and droughts will increase, and the trade-offs between reservoir releases to maintain flood control storage, drought resilience, ecological flow, human water demand, and energy production should be reconsidered. We used a Neural Networks based General Reservoir Operation Scheme to estimate the implications of climate change for dams on a regional scale. This dynamic daily reservoir module automatically adapts to changes in climate and re-adjusts the operation of dams based on water storage level, timing, and magnitude of incoming flows. Our findings suggest that the importance of dams in providing water security in the region will increase. We create an indicator of the Effective Degree of Regulation (EDR) by dams on water resources and show that it is expected to increase, particularly during drier months of year, simply as a consequence of projected climate change. The results also indicate that increasing the size and number of dams, in addition to modifying their operations, may become necessary to offset the vulnerabilities of water resources systems to future climate uncertainties. This is the case even without considering the likely increase in future water demand, especially in the most densely populated regions of the Northeast.

Panorama 2014 - The importance of underground storage in the security of European gas supplies

International Nuclear Information System (INIS)

Cornot-Gandolphe, Sylvie

2013-12-01

While European capacity for underground gas storage has increased by 16% over the last three years, levels of stock at the beginning of the 2013/2014 winter, in relation to capacity, are the lowest that have been seen since 2010; they represent only 84% of storage capacity. The suppliers of gas have no incentive to reserve storage capacity, for which the cost is considered too high in relation to the spread, currently very low, between the price of gas in winter and in summer. They also rely on sufficient gas supply thanks to other sources of flexibility available on the market: flexibility of production or imports, spot LNG purchases, purchases in the spot market... or even use of the storage capacities of neighbouring countries via European network interconnections. Yet, the 2013/2014 winter is beginning in a gas supply context in Europe that is more difficult: imports of LNG, which had already dropped sharply in 2012, have continued to contract, faced with increased competition from Asian buyers on the international LNG market. Gas imports from Norway are also declining following production limits in that country. Only Russia has strongly increased its exports to Europe in 2013. However, the dispute between Ukraine and Russia about the price of Russian gas delivered to Ukraine still raises the spectre of a threat to the European supply of Russian gas, nearly 60% of which transits via Ukraine. Under these circumstances, as demonstrated by the gas crises of 2006 and 2009 and the cold conditions of February 2012 and March/April 2013, storage is the most efficient means of securing the supply of gas providing, of course, that the storage sites are filled at the beginning of winter. (author)

Hydrogen storage in complex hydrides

International Nuclear Information System (INIS)

Lupu, D.; Biris, A. R.; Misan, I.

2005-01-01

Full text: Hydrogen storage is a key enabling technology for the advancement of hydrogen and fuel cell power technologies in mobile and stationary applications. A relevant role of the fuel cell powered vehicles on the market of the transportation systems will be achieved only if the research and development of on-board vehicular hydrogen storage are able to allow a driving range of at least 500 km. The on-board hydrogen storage systems are more challenging due to the space, weight and cost limitations. This range of autonomy between refueling requires materials able to store at least 6.5% weight hydrogen, available at moderate pressures, at the working temperature of the fuel cells and with acceptable cycling stability. The intensive research on the hydrogen storage in alloys and intermetallic of the LaNi 5 , FeTi or Laves phase type compounds, which started more than three decades ago did not resulted in materials of more than about 3% H storage capacities. The 7.5% H content of the Mg hydride is still of attracting interest but though the absorption has been achieved at lower temperatures by ball milling magnesium with various amounts of nickel, the desorption can not be attained at 1 bar H 2 below 280 deg. C and the kinetics of the process is too slow. In the last decade, the attention is focused on another class of compounds, the complex hydrides of aluminum with alkali metals (alanates), due to their high hydrogen content. It was found that doping with Ti-based catalysts improve the hydrogenation/dehydrogenation conditions of NaAlH 4 . Later on, it was shown that ball milling with solid state catalysts greatly improve the hydrogen desorption kinetics of NaAlH 4 , and this also helps to the rehydriding process. The hydrogen desorption from NaAlH 4 occurs in three steps, it shows a reversible storage capacity of 5.5% H and this led to further research work for a better knowledge of its application relating properties. In this work, ball milling experiments on Na

Multiplexed optical data storage and vectorial ray tracing

Directory of Open Access Journals (Sweden)

Foreman M.R.

2010-06-01

Full Text Available With the motivation of creating a terabyte-sized optical disk, a novel imaging technique is implemented. This technique merges two existing technologies: confocal microscopy and Mueller matrix imaging. Mueller matrix images from a high numerical space are obtained. The acquisition of these images makes the exploration of polarisation properties in a sample possible. The particular case of optical data storage is used as an example in this presentation. Since we encode information into asymmetric datapits (see Figure 1, the study of the polarisation of the scattered light can then be used to recover the orientation of the pit. It is thus possible to multiplex information by changing the angle of the mark. The storage capacity in the system is hence limited by the number of distinct angles that the optical system can resolve. This presentation thus answers the question; what is the current storage capacity of a polarisation sensitive optical disk? After a brief introduction to polarisation, the decoding method and experimental results are presented so as to provide an answer to this question. With the aim of understanding high NA focusing, an introduction to vectorial ray tracing is then given.

Economical evaluation on spent fuel storage technology away from reactor

International Nuclear Information System (INIS)

Itoh, Chihiro; Nagano, Koji; Saegusa, Toshiari

2000-01-01

Concerning the spent fuel storage away from reactor, economical comparison was carried out between metal cask and water pool storage technology. The economic index was defined by levelized cost (Unit storage cost) calculated on the assumption that the storage cost is paid at the receipt of the spent fuel at the storage facility. It is found that the cask storage is economical for small and large storage capacity. Unit storage cost of pool storage, however, is getting close to that of cask storage in case of storage capacity of 10,000 ton. Then, the unit storage cost is converted to power generation cost using data of the burn up of the fuel, etc. The cost is obtained as yen 0.09/kWh and yen 0. 15/kWh for cask storage and pool storage, respectively in case of the capacity of 5,000 tonU and the cooling time of 5 years. (author)

Hydrogen storage capacity of lithium-doped KOH activated carbons

International Nuclear Information System (INIS)

Minoda, Ai; Oshima, Shinji; Iki, Hideshi; Akiba, Etsuo

2014-01-01

Highlights: • The hydrogen adsorption of lithium-doped KOH activated carbons has been studied. • Lithium doping improves their hydrogen adsorption affinity. • Lithium doping is more effective for materials with micropores of 0.8 nm or smaller. • Lithium reagent can alter the pore structure, depending on the raw material. • Optimizing the pore size and functional group is needed for better hydrogen uptake. - Abstract: The authors have studied the hydrogen adsorption performance of several types of lithium-doped KOH activated carbons. In the case of activated cokes, lithium doping improves their hydrogen adsorption affinity from 5.02 kg/m 3 to 5.86 kg/m 3 at 303 K. Hydrogen adsorption density increases by around 17% after lithium doping, likely due to the fact that lithium doping is more effective for materials with micropores of 0.8 nm or smaller. The effects of lithium on hydrogen storage capacity vary depending on the raw material, because the lithium reagent can react with the material and alter the pore structure, indicating that lithium doping has the effect of plugging or filling the micropores and changing the structures of functional groups, resulting in the formation of mesopores. Despite an observed decrease in hydrogen uptake, lithium doping was found to improve hydrogen adsorption affinity. Lithium doping increases hydrogen uptake by optimizing the pore size and functional group composition

Saline Cavern Adiabatic Compressed Air Energy Storage Using Sand as Heat Storage Material

Directory of Open Access Journals (Sweden)

Martin Haemmerle

2017-03-01

Full Text Available Adiabatic compressed air energy storage systems offer large energy storage capacities and power outputs beyond 100MWel. Salt production in Austria produces large caverns which are able to hold pressure up to 100 bar, thus providing low cost pressurized air storage reservoirs for adiabatic compressed air energy storage plants. In this paper the results of a feasibility study is presented, which was financed by the Austrian Research Promotion Agency, with the objective to determine the adiabatic compressed air energy storage potential of Austria’s salt caverns. The study contains designs of realisable plants with capacities between 10 and 50 MWel, applying a high temperature energy storage system currently developed at the Institute for Energy Systems and Thermodynamics in Vienna. It could be shown that the overall storage potential of Austria’s salt caverns exceeds a total of 4GWhel in the year 2030 and, assuming an adequate performance of the heat exchanger, that a 10MWel adiabatic compressed air energy storage plant in Upper Austria is currently feasible using state of the art thermal turbomachinery which is able to provide a compressor discharge temperature of 400 °C.

Maximum Throughput in a C-RAN Cluster with Limited Fronthaul Capacity

OpenAIRE

Duan , Jialong; Lagrange , Xavier; Guilloud , Frédéric

2016-01-01

International audience; Centralized/Cloud Radio Access Network (C-RAN) is a promising future mobile network architecture which can ease the cooperation between different cells to manage interference. However, the feasibility of C-RAN is limited by the large bit rate requirement in the fronthaul. This paper study the maximum throughput of different transmission strategies in a C-RAN cluster with transmission power constraints and fronthaul capacity constraints. Both transmission strategies wit...

Monitored Retrievable Storage conceptual system study: metal storage casks

International Nuclear Information System (INIS)

Unterzuber, R.; Cross, T.E.; Krasicki, B.R.

1983-08-01

A description of the metal cask storage facility concept is presented with the operations required to handle the spent fuel or high-level wastes and transuranic wastes. A generic Receiving and Handling Facility, provided by PNL, has been used for this study. Modifications to the storage delivery side of the handling facility, necessary to couple the Receiving and Handling Facility with the storage facility, are described. The equipment and support facilities needed for the storage facility are also described. Two separate storage facilities are presented herein: one for all spent fuel storage, and one for storage of high-level waste (HLW) and transuranic waste (TRU). Each facility is described for the capacities and rates defined by PNL in the Concept Technical Performance Criteria and Base Assumptions (see Table 1.3-1). Estimates of costs and time-distributions of expenditures have been developed to construct, operate, and decommission the conceptual MRS facilities in mid-1983 dollars, for the base cases given using the cost categories and percentages provided by PNL. Cost estimates and time-distributions of expenditures have also been developed to expand the facility throughput rate from 1800 MTU to 3000 MTU, and to expand the facility storage capacity from 15,000 MTU to 72,00 MTU. The life cycle cost of the facility for the bounding cases of all spent fuel and all HLW and TRU, using the time-distributions of costs developed above and assuming a two percent per year discount rate, are also presented. 3 references, 16 figures, 18 tables

Hydrogen transport and storage in engineered glass microspheres

Energy Technology Data Exchange (ETDEWEB)

Rambach, G.D.

1995-02-28

New, high strength glass microspheres filled with pressurized hydrogen exhibit densities which make them attractive for bulk hydrogen storage and transport. The membrane tensile stress at failure for engineered glass microspheres is about 150,000 psi, permitting a three-fold increase in pressure limit and storage capacity above commercial microspheres, which have been studied a decade ago and have been shown to fail at membrane stresses of 50,000 psi. This analysis relating glass microspheres for hydrogen transport with infrastructure and economics, indicate that pressurized microspheres can be economically competitive with other forms of bulk rail and truck transport such as pressurized tube transports and liquid hydrogen trailers. This paper will describe the matching of current glass microspheres with the useful application in commercial hydrogen bulk transport and storage.

Hydrogen transport and storage in engineered glass microspheres

Energy Technology Data Exchange (ETDEWEB)

Rambach, G.D.

1995-04-18

New, high strength glass microspheres filled with pressurized hydrogen exhibit densities which make them attractive for bulk hydrogen storage and transport. The membrane tensile stress at failure for our engineered glass microspheres is about 150,000 psi, permitting a threefold increase in pressure limit and storage capacity above commercial microspheres, which have been studied a decade ago and have been shown to fail at membrane stresses of 50,000 psi. Our analysis relating glass microspheres for hydrogen transport with infrastructure and economics, indicate that pressurized microspheres can be economically competitive with other forms of bulk rail and truck transport such as pressurized tube transports and liquid hydrogen trailers.

Hydrogen storage in carbon nanotubes.

Science.gov (United States)

Hirscher, M; Becher, M

2003-01-01

The article gives a comprehensive overview of hydrogen storage in carbon nanostructures, including experimental results and theoretical calculations. Soon after the discovery of carbon nanotubes in 1991, different research groups succeeded in filling carbon nanotubes with some elements, and, therefore, the question arose of filling carbon nanotubes with hydrogen by possibly using new effects such as nano-capillarity. Subsequently, very promising experiments claiming high hydrogen storage capacities in different carbon nanostructures initiated enormous research activity. Hydrogen storage capacities have been reported that exceed the benchmark for automotive application of 6.5 wt% set by the U.S. Department of Energy. However, the experimental data obtained with different methods for various carbon nanostructures show an extreme scatter. Classical calculations based on physisorption of hydrogen molecules could not explain the high storage capacities measured at ambient temperature, and, assuming chemisorption of hydrogen atoms, hydrogen release requires temperatures too high for technical applications. Up to now, only a few calculations and experiments indicate the possibility of an intermediate binding energy. Recently, serious doubt has arisen in relation to several key experiments, causing considerable controversy. Furthermore, high hydrogen storage capacities measured for carbon nanofibers did not survive cross-checking in different laboratories. Therefore, in light of today's knowledge, it is becoming less likely that at moderate pressures around room temperature carbon nanostructures can store the amount of hydrogen required for automotive applications.

Spent fuel storage requirements, 1990--2040

International Nuclear Information System (INIS)

Walling, R.; Bierschbach, M.

1990-11-01

Historical inventories of spent fuel are combined with US Department of Energy (DOE) projections of future discharges from commercial nuclear reactors in the United States to provide estimates of spent fuel storage requirements over the next 51 years, through the year 2040. The needs for storage capacity beyond that presently available in the pools are estimated. These estimates incorporate the maximum capacities within current and planned in-pool storage facilities and any planned transshipments of fuel to other reactors or facilities. Existing and future dry storage facilities are also discussed. Historical data through December 1989 are derived from the 1990 Form RW-859 data survey of nuclear utilities. Projected discharges through the end of reactor life are based on DOE estimates of future nuclear capacity, generation, and spent fuel discharges. 15 refs., 3 figs., 11 tabs

Analysis of Optical CDMA Signal Transmission: Capacity Limits and Simulation Results

Directory of Open Access Journals (Sweden)

Lawrence R. Chen

2005-06-01

Full Text Available We present performance limits of the optical code-division multiple-access (OCDMA networks. In particular, we evaluate the information-theoretical capacity of the OCDMA transmission when single-user detection (SUD is used by the receiver. First, we model the OCDMA transmission as a discrete memoryless channel, evaluate its capacity when binary modulation is used in the interference-limited (noiseless case, and extend this analysis to the case when additive white Gaussian noise (AWGN is corrupting the received signals. Next, we analyze the benefits of using nonbinary signaling for increasing the throughput of optical CDMA transmission. It turns out that up to a fourfold increase in the network throughput can be achieved with practical numbers of modulation levels in comparison to the traditionally considered binary case. Finally, we present BER simulation results for channel coded binary and M-ary OCDMA transmission systems. In particular, we apply turbo codes concatenated with Reed-Solomon codes so that up to several hundred concurrent optical CDMA users can be supported at low target bit error rates. We observe that unlike conventional OCDMA systems, turbo-empowered OCDMA can allow overloading (more active users than is the length of the spreading sequences with good bit error rate system performance.

Analysis of Optical CDMA Signal Transmission: Capacity Limits and Simulation Results

Science.gov (United States)

Garba, Aminata A.; Yim, Raymond M. H.; Bajcsy, Jan; Chen, Lawrence R.

2005-12-01

We present performance limits of the optical code-division multiple-access (OCDMA) networks. In particular, we evaluate the information-theoretical capacity of the OCDMA transmission when single-user detection (SUD) is used by the receiver. First, we model the OCDMA transmission as a discrete memoryless channel, evaluate its capacity when binary modulation is used in the interference-limited (noiseless) case, and extend this analysis to the case when additive white Gaussian noise (AWGN) is corrupting the received signals. Next, we analyze the benefits of using nonbinary signaling for increasing the throughput of optical CDMA transmission. It turns out that up to a fourfold increase in the network throughput can be achieved with practical numbers of modulation levels in comparison to the traditionally considered binary case. Finally, we present BER simulation results for channel coded binary and[InlineEquation not available: see fulltext.]-ary OCDMA transmission systems. In particular, we apply turbo codes concatenated with Reed-Solomon codes so that up to several hundred concurrent optical CDMA users can be supported at low target bit error rates. We observe that unlike conventional OCDMA systems, turbo-empowered OCDMA can allow overloading (more active users than is the length of the spreading sequences) with good bit error rate system performance.

Use of burnup credit for transportation and storage

International Nuclear Information System (INIS)

Sanders, T.L.; Ewing, R.I.; Lake, W.H.

1991-01-01

Burnup credit is the application of the effects of fuel burnup to nuclear criticality design. When burnup credit is considered in the design of storage facilities and transportation casks for spent fuel, the objectives are to reduce the requirements for storage space and to increase the payload of casks with acceptable nuclear criticality safety margins. The spent-fuel carrying capacities of previous-generation transport casks have been limited primarily by requirements to remove heat and/or to provide shielding. Shielding and heat transfer requirements for casks designed to transport older spent fuel with longer decay times are reduced significantly. Thus a considerable weight margin is available to the designer for increasing the payload capacity. One method to achieve an increase in capacity is to reduce fuel assembly spacing. The amount of reduction in assembly spacing is limited by criticality and fuel support structural concerns. The optimum fuel assembly spacing provides the maximum cask loading within a basket that has adequate criticality control and sufficient structural integrity for regulatory accident scenarios. The incorporation of burnup credit in cask designs could result in considerable benefits in the transport of spent fuel. The acceptance of burnup credit for the design of transport casks depends on the resolution of system safety issues and the uncertainties that affect the determination of criticality safety margins. The remainder of this report will examine these issues and the integrated approach under way to resolve them. 20 refs., 2 figs

Developing new transportable storage casks for interim dry storage

International Nuclear Information System (INIS)

Hayashi, K.; Iwasa, K.; Araki, K.; Asano, R.

2004-01-01

Transportable storage metal casks are to be consistently used during transport and storage for AFR interim dry storage facilities planning in Japan. The casks are required to comply with the technical standards of regulations for both transport (hereinafter called ''transport regulation'') and storage (hereafter called ''storage regulation'') to maintain safety functions (heat transfer, containment, shielding and sub-critical control). In addition to these requirements, it is not planned in normal state to change the seal materials during storage at the storage facility, therefore it is requested to use same seal materials when the casks are transported after storage period. The dry transportable storage metal casks that satisfy the requirements have been developed to meet the needs of the dry storage facilities. The basic policy of this development is to utilize proven technology achieved from our design and fabrication experience, to carry out necessary verification for new designs and to realize a safe and rational design with higher capacity and efficient fabrication

Future Hard Disk Storage: Limits & Potential Solutions

Science.gov (United States)

Lambeth, David N.

2000-03-01

For several years the hard disk drive technology pace has raced along at 60-100products this year and laboratory demonstrations approaching what has been estimated as a physical thermal stability limit of around 40 Gbit/in2. For sometime now the data storage industry has recogniz d that doing business as usually will not be viable for long and so both incremental evolutionary and revolutionary technologies are being explored. While new recording head materials or thermal recording techniques may allow higher coercivity materials to be recorded upon, and while high sensitivity spin transport transducer technology may provide sufficient signals to extend beyond the 100 Gigabit/in2 regime, conventional isotropic longitudinal media will show large data retention problems at less than 1/2 of this value. We have recently developed a simple model which indicates that while thermal instability issues may appear at different areal densities, they are non-discriminatory as to the magnetic recording modality: longitudinal, perpendicular, magnetooptic, near field, etc. The model indicates that a strong orientation of the media tends to abate the onset of the thermal limit. Hence, for the past few years we have taken an approach of controlled growth of the microstructure of thin film media. This knowledge has lead us to believe that epitaxial growth of multiple thin film layers on single crystalline Si may provide a pathway to nearly perfect crystallites of various, highly oriented, thin film textures. Here we provide an overview of the recording system media challenges, which are useful for the development of a future media design philosophy and then discuss materials issues and processing techniques for multi-layered thin film material structures which may be used to achieve media structures which can easy exceed the limits predicted for isotropic media.

Near-surface storage facilities for vitrified high-level wastes

International Nuclear Information System (INIS)

Kondrat'ev, A.N.; Kulichenko, V.V.; Kryukov, I.I.; Krylova, N.V.; Paramoshkin, V.I.; Strakhov, M.V.

1980-01-01

Concurrently with the development of methods for solidifying liquid radioactive wastes, reliable and safe methods for the storage and disposal of solidified wastes are being devised in the USSR and other countries. One of the main factors affecting the choice of storage conditions for solidified wastes originating from the vitrification of high-level liquid wastes from fuel reprocessing plants is the problem of removing the heat produced by radioactive decay. In order to prevent the temperature of solidified wastes from exceeding the maximum permissible level for the material concerned, it is necessary to limit either the capacity of waste containers or the specific heat release of the wastes themselves. In order that disposal of high-level wastes in geological formations should be reliable and economic, solidified wastes undergo interim storage in near-surface storage facilities with engineered cooling systems. The paper demonstrates the relative influences of specific heat release, of the maximum permissible storage temperature for vitrified wastes and of the methods chosen for cooling wastes in order for the dimensions of waste containers to be reduced to the extent required. The effect of concentrating wastes to a given level in the vitrification process on the cost of storage in different types of storage facility is also examined. Calculations were performed for the amount of vitrified wastes produced by a reprocessing plant with a capacity of five tonnes of uranium per 24 hours. Fuel elements from reactors of the water-cooled, water-moderated type are sent for reprocessing after having been held for about two years. The dimensions of the storage facility are calculated on the assumption that it will take five years to fill

The potential of geological storage of CO2 in Austria: a techno-economic assessment

Science.gov (United States)

Brüstle, Anna Katharina; Welkenhuysen, Kris; Bottig, Magdalena; Piessens, Kris; Ramirez, Andrea; Swenner, Rudy

2014-05-01

economic uncertainties. Results indicate a significant potential for CCS in Austria and a very high probability for any CO2 storage activity. The assessment of the average practical capacity of the whole country is 120Mt at 15€/tCO2 of storage budget, while the average matched national capacity is 40Mt. Concerning the individual reservoirs, reservoir development probabilities generally lie between 20 and 30%. These numbers served as basis for a reservoir exploration ranking. Compared to current emissions, total storage capacity is at the low end, which is likely the main technical limiting factor for CCS deployment in Austria. Also, current policy seems not in favour of CCS. Storage capacity is however high enough to provide a significant contribution to the reduction of CO2 emissions in the country, in the order of a few million tonnes per year. Opportunities to combine CO2 geological storage and geothermal energy seem promising, but require additional evaluation. Welkenhuysen, K., Ramirez, A., Swennen, R. & Piessens, K., 2013. Ranking potential CO2 storage reservoirs: an exploration priority list for Belgium. International Journal of Greenhouse Gas Control, 17, p. 431-449

Volume Holographic Storage of Digital Data Implemented in Photorefractive Media

Science.gov (United States)

Heanue, John Frederick

A holographic data storage system is fundamentally different from conventional storage devices. Information is recorded in a volume, rather than on a two-dimensional surface. Data is transferred in parallel, on a page-by -page basis, rather than serially. These properties, combined with a limited need for mechanical motion, lead to the potential for a storage system with high capacity, fast transfer rate, and short access time. The majority of previous volume holographic storage experiments have involved direct storage and retrieval of pictorial information. Success in the development of a practical holographic storage device requires an understanding of the performance capabilities of a digital system. This thesis presents a number of contributions toward this goal. A description of light diffraction from volume gratings is given. The results are used as the basis for a theoretical and numerical analysis of interpage crosstalk in both angular and wavelength multiplexed holographic storage. An analysis of photorefractive grating formation in photovoltaic media such as lithium niobate is presented along with steady-state expressions for the space-charge field in thermal fixing. Thermal fixing by room temperature recording followed by ion compensation at elevated temperatures is compared to simultaneous recording and compensation at high temperature. In particular, the tradeoff between diffraction efficiency and incomplete Bragg matching is evaluated. An experimental investigation of orthogonal phase code multiplexing is described. Two unique capabilities, the ability to perform arithmetic operations on stored data pages optically, rather than electronically, and encrypted data storage, are demonstrated. A comparison of digital signal representations, or channel codes, is carried out. The codes are compared in terms of bit-error rate performance at constant capacity. A well-known one-dimensional digital detection technique, maximum likelihood sequence estimation, is

Capacity market design and renewable energy: Performance incentives, qualifying capacity, and demand curves

Energy Technology Data Exchange (ETDEWEB)

Botterud, Audun; Levin, Todd; Byers, Conleigh

2018-01-01

A review of capacity markets in the United States in the context of increasing levels of variable renewable energy finds substantial differences with respect to incentives for operational performance, methods to calculate qualifying capacity for variable renewable energy and energy storage, and demand curves for capacity. The review also reveals large differences in historical capacity market clearing prices. The authors conclude that electricity market design must continue to evolve to achieve cost-effective policies for resource adequacy.

Downlink Multicell Processing with Limited-Backhaul Capacity

Directory of Open Access Journals (Sweden)

O. Simeone

2009-01-01

Full Text Available Multicell processing in the form of joint encoding for the downlink of a cellular system is studied under the assumption that the base stations (BSs are connected to a central processor (CP via finitecapacity links (finite-capacity backhaul. To obtain analytical insight into the impact of finite-capacity backhaul on the downlink throughput, the investigation focuses on a simple linear cellular system (as for a highway or a long avenue based on theWyner model. Several transmission schemes are proposed that require varying degrees of knowledge regarding the system codebooks at the BSs. Achievable rates are derived in closed-form and compared with an upper bound. Performance is also evaluated in asymptotic regimes of interest (high backhaul capacity and extreme signal-to-noise ratio, SNR and further corroborated by numerical results. The major finding of this work is that even in the presence of oblivious BSs (that is, BSs with no information about the codebooks multicell processing is able to provide ideal performance with relatively small backhaul capacities, unless the application of interest requires high data rate (i.e., high SNR and the backhaul capacity is not allowed to increase with the SNR. In these latter cases, some form of codebook information at the BSs becomes necessary.

Mathematical Model of (R,Q Inventory Policy under Limited Storage Space for Continuous and Periodic Review Policies with Backlog and Lost Sales

Directory of Open Access Journals (Sweden)

Kanokwan Singha

2017-01-01

Full Text Available This paper involves developing new mathematical expressions to find reorder point and order quantity for inventory management policies that explicitly consider storage space capacity. Both continuous and periodic reviews, as well as backlogged and lost demand during stockout, are considered. With storage space capacity, when on-hand inventory exceeds the capacity, the over-ordering cost of storage at an external warehouse is charged on a per-unit-period basis. The objective is to minimize the total cost, consisting of ordering, shortage, holding, and over-ordering costs. Demand and lead time are stochastic and discrete in nature. Demand during varying lead time is modeled using an empirical distribution so that the findings are not subject to assumptions of demand and lead time probability distributions. Due to the complexity of the developed mathematical expressions, the problems are solved using an iterative method. The method is tested with problem instances that use real data from industry. Optimal solutions of the problem instance are determined by performing exhaustive search. The proposed method can effectively find optimal solutions for continuous review policies and near optimal solutions for periodic review policies. Fundamental insights about the inventory policies are reported from a comparison between continuous review and periodic review solutions, as well as a comparison between backlog and lost sales cases.

Inventory of future power and heat production technologies. Partial report Energy storage; Inventering av framtidens el- och vaermeproduktionstekniker. Delrapport Energilagring

Energy Technology Data Exchange (ETDEWEB)

Messing, Lars; Lindahl, Sture [Gothia Power AB, Goeteborg (Sweden)

2008-12-15

In this report a survey of different techniques for storage of electrical energy. The following alternatives are described regarding method, characteristics, potential and economy. Batteries; Capacitors; Flywheels; Pump storage hydro power plants; Hydrogen gas generation; Air compression. Regarding evaluation of methods for storage of electrical energy. Battery storage: The development of Lithium-ion batteries are of great interest. In the present situation it is however difficult of classify battery storage as a good alternation in applications with frequent re-charging cycles and re-charging of large energy volumes. The batteries have limited life length compared to other alternatives. Also the power is limited at charging and discharging. Energy storage in capacitors: 'Super-capacitors' having large power capacity is considered to be of interest in applications where fast control of power is necessary. The ongoing development of based on carbon-nanotubes will increase the energy storage capacity compared with the today existing super-capacitors. This can in the future be an alternative to battery storage. Of further interest is also the idea to combine battery and capacitor based storage to achieve longer life-time of the batteries and faster power control. Flywheel energy storage: The energy storage capacity is relatively limited but power control can be fast. This system can be an alternative to capacitor based energy storage. Pump-storage hydro power plant: This type of energy storage is well suited and proven for time frame up to some days. In the Swedish power system there is today not any large demand of energy storage in this time frame as there is a large capacity in conventional hydro power plants with storage capacity. Pump-storage can however be of interest in the southern part of Sweden. In some operation stages the grid is loaded up to its limit due to large power transmission from the north. The pump-storage can reduce this power transfer during

Inventory of future power and heat production technologies. Partial report Energy storage; Inventering av framtidens el- och vaermeproduktionstekniker. Delrapport Energilagring

Energy Technology Data Exchange (ETDEWEB)

Messing, Lars; Lindahl, Sture (Gothia Power AB, Goeteborg (Sweden))

2008-12-15

In this report a survey of different techniques for storage of electrical energy. The following alternatives are described regarding method, characteristics, potential and economy. Batteries; Capacitors; Flywheels; Pump storage hydro power plants; Hydrogen gas generation; Air compression. Regarding evaluation of methods for storage of electrical energy. Battery storage: The development of Lithium-ion batteries are of great interest. In the present situation it is however difficult of classify battery storage as a good alternation in applications with frequent re-charging cycles and re-charging of large energy volumes. The batteries have limited life length compared to other alternatives. Also the power is limited at charging and discharging. Energy storage in capacitors: 'Super-capacitors' having large power capacity is considered to be of interest in applications where fast control of power is necessary. The ongoing development of based on carbon-nanotubes will increase the energy storage capacity compared with the today existing super-capacitors. This can in the future be an alternative to battery storage. Of further interest is also the idea to combine battery and capacitor based storage to achieve longer life-time of the batteries and faster power control. Flywheel energy storage: The energy storage capacity is relatively limited but power control can be fast. This system can be an alternative to capacitor based energy storage. Pump-storage hydro power plant: This type of energy storage is well suited and proven for time frame up to some days. In the Swedish power system there is today not any large demand of energy storage in this time frame as there is a large capacity in conventional hydro power plants with storage capacity. Pump-storage can however be of interest in the southern part of Sweden. In some operation stages the grid is loaded up to its limit due to large power transmission from the north. The pump-storage can reduce this power transfer

Uncertainties in criticality analysis which affect the storage and transportation of LWR fuel

International Nuclear Information System (INIS)

Napolitani, D.G.

1989-01-01

Satisfying the design criteria for subcriticality with uncertainties affects: the capacity of LWR storage arrays, maximum allowable enrichment, minimum allowable burnup and economics of various storage options. There are uncertainties due to: calculational method, data libraries, geometric limitations, modelling bias, the number and quality of benchmarks performed and mechanical uncertainties in the array. Yankee Atomic Electric Co. (YAEC) has developed and benchmarked methods to handle: high density storage rack designs, pin consolidation, low density moderation and burnup credit. The uncertainties associated with such criticality analysis are quantified on the basis of clean criticals, power reactor criticals and intercomparison of independent analysis methods

Analysis of ice cool thermal storage for a clinic building in Kuwait

International Nuclear Information System (INIS)

Sebzali, M.J.; Rubini, P.A.

2006-01-01

In Kuwait, air conditioning (AC) systems consume 61% and 40% of the peak electrical load and total electrical energy, respectively. This is due to a very high ambient temperature for the long summer period extended from April to October and the low energy cost. This paper gives an overview of the electrical peak and energy consumption in Kuwait, and it has been found that the average increase in the annual peak electrical demand and energy consumption for the year 1998-2002 was 6.2% and 6.4%, respectively. One method of reducing the peak electrical demand of AC systems during the day period is by incorporating an ice cool thermal storage (ICTS) with the AC system. A clinic building has been selected to study the effects of using an ICTS with different operation strategies such as partial (load levelling), partial (demand limiting) and full storage operations on chiller and storage sizes, reduction of peak electrical demand and energy consumption of the chiller for selected charging and discharging hours. It has been found that the full storage operation has the largest chiller and storage capacities, energy consumption and peak electrical reduction. However, partial storage (load levelling) has the smallest chiller and storage capacities and peak electrical reduction. This paper also provides a detailed comparison of using ICTS operating strategies with AC and AC systems without ICTS

Mechanisms limiting glycogen storage in muscle during prolonged insulin stimulation

DEFF Research Database (Denmark)

Richter, Erik; Hansen, S A; Hansen, B F

1988-01-01

increased muscle glycogen concentrations to maximal values 2, 3, and 3.5 times above normal fed levels in fast-twitch white, slow-twitch red, and fast-twitch red fibers, respectively. Glucose uptake decreased (mean +/- SE) from 34.9 +/- 1.2 mumol.g-1.h-1 at 0 h to 7.5 +/- 0.7 after 7 h of perfusion. During...... compared with initial values. Total muscle water concentration decreased during glycogen loading of the muscles. Mechanisms limiting glycogen storage under maximal insulin stimulation include impaired insulin-stimulated membrane transport of glucose as well as impaired intracellular glucose disposal....

ANTIOXIDANT CAPACITY OF PEQUI (Caryocar brasiliense Camb. PULP IS PRESERVED BY FREEZE-DRYING AND LIGHT-RESISTANT PACKAGING

Directory of Open Access Journals (Sweden)

NARA RÚBIA RODRIGUES DO NASCIMENTO

Full Text Available ABSTRACT Pequi (Caryocar brasiliense Camb. pulp is rich in bioactive compounds. However, seasonality and perishability limit its availability in the market. This work aimed to determine the physicochemical characteristics, including phenolic compounds and carotenoid concentrations, as well as the antioxidant capacity of lyophilized pequi pulp during storage in various packaging materials for 180 days. Pequi fruits were pulped, ground, freeze-dried and then vacuum packaged in transparent polyethylene (TP, polyethylene coated by aluminum foil (PA and laminated foil (LA, respectively. The samples were stored under controlled temperature, humidity and luminosity. Proximate composition, phenolic compounds and carotenoids concentrations, and antioxidant capacity (DPPH• assay were determined at the beginning of the study and the end of each month, during 180 days. Lyophilized pequi pulp had 48.87, 6.17, and 4.20 g.100 g-1 lipids, proteins, and total dietary fiber, respectively, and 556.79 kcal.100 g-1 energy. PA and LA had similar effects against light-induced carotenoid oxidation. Negative correlations between the phenolic compound concentration and storage period, and antioxidant capacity and storage period; and a positive correlation between antioxidant capacity and phenolic compound content were observed. Light-resistant packaging decreased the carotenoid loss. Among the packaging, LA preserved the phenolic compounds and antioxidant capacity most effectively.

Depressive thoughts limit working memory capacity in dysphoria.

Science.gov (United States)

Hubbard, Nicholas A; Hutchison, Joanna L; Turner, Monroe; Montroy, Janelle; Bowles, Ryan P; Rypma, Bart

2016-01-01

Dysphoria is associated with persistence of attention on mood-congruent information. Longer time attending to mood-congruent information for dysphoric individuals (DIs) detracts from goal-relevant information processing and should reduce working memory (WM) capacity. Study 1 showed that DIs and non-DIs have similar WM capacities. Study 2 embedded depressive information into a WM task. Compared to non-DIs, DIs showed significantly reduced WM capacity for goal-relevant information in this task. Study 3 replicated results from Studies 1 and 2, and further showed that DIs had a significantly greater association between processing speed and recall on the depressively modified WM task compared to non-DIs. The presence of inter-task depressive information leads to DI-related decreased WM capacity. Results suggest dysphoria-related WM capacity deficits when depressive thoughts are present. WM capacity deficits in the presence of depressive thoughts are a plausible mechanism to explain day-to-day memory and concentration difficulties associated with depressed mood.

The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information.

Science.gov (United States)

Miller, George A.

1994-01-01

Capacity limitations in absolute judgment tasks are discussed in relation to information theory. Information theory can provide a quantitative way of resolving questions about limitations on the amount of information we can receive and the process of recoding. (SLD)

Delay-limited capacity of fading multiple access and broadcast channels in the low power regime

KAUST Repository

Rezki, Zouheir

2015-09-11

We study delay-limited (also called zero-outage) capacity region of the fading multi-access channel (MAC) with Gaussian noise and perfect channel state information (CSI) at the receiver and at the transmitters (CSI-TR), in the low-power regime. We show that for fading channels where the MAC capacity region is strictly positive, it has a multidimensional rectangle structure and thus is simply characterized by single user capacity points. More specifically, we show that at low power, the boundary surface of the capacity region shrinks to a single point corresponding to the sum-rate maximizer and that the coordinates of this point coincide with single user capacity bounds. Using the duality of the Gaussian MAC and broadcast channels (BC), we show that time-sharing (or time division multiple access (TDMA)) is asymptotically optimal. © 2015 IEEE.

Storage capacity assessment of liquid fuels production by solar gasification in a packed bed reactor using a dynamic process model

International Nuclear Information System (INIS)

Kaniyal, Ashok A.; Eyk, Philip J. van; Nathan, Graham J.

2016-01-01

of syngas throughput that could be maintained over a full year by 74%, to 5.9 kmol/day. Importantly, a larger heliostat field collection area was calculated to reduce the required storage capacity to approximately halve 35 days, which in absolute terms corresponds to 3.0 tons of syngas. Nevertheless, a requirement for this capacity of storage suggests that the use of the packed bed solar gasification reactor for FT liquids production is unlikely to be viable without substantial changes to the design and operation of the reactor and/or downstream processing plant.

Storage tank stratification/rollover alarm management. Liquefied natural gas

Energy Technology Data Exchange (ETDEWEB)

Versluijs, Pieter [Waertsilae France SAS, Calais (France). Waertsilae Whessoe PCT

2011-03-21

Liquefied natural gas (LNG) terminals need to be able to store multiple grades of LNG, and to have sufficient storage capacity available for all of them. Managing storage to ensure availability and to optimise the use of storage capacity is, therefore, essential. This article discusses ways of achieving these aims.

Diffused holographic information storage and retrieval using photorefractive optical materials

Science.gov (United States)

McMillen, Deanna Kay

Holography offers a tremendous opportunity for dense information storage, theoretically one bit per cubic wavelength of material volume, with rapid retrieval, of up to thousands of pages of information simultaneously. However, many factors prevent the theoretical storage limit from being reached, including dynamic range problems and imperfections in recording materials. This research explores new ways of moving closer to practical holographic information storage and retrieval by altering the recording materials, in this case, photorefractive crystals, and by increasing the current storage capacity while improving the information retrieved. As an experimental example of the techniques developed, the information retrieved is the correlation peak from an optical recognition architecture, but the materials and methods developed are applicable to many other holographic information storage systems. Optical correlators can potentially solve any signal or image recognition problem. Military surveillance, fingerprint identification for law enforcement or employee identification, and video games are but a few examples of applications. A major obstacle keeping optical correlators from being universally accepted is the lack of a high quality, thick (high capacity) holographic recording material that operates with red or infrared wavelengths which are available from inexpensive diode lasers. This research addresses the problems from two positions: find a better material for use with diode lasers, and reduce the requirements placed on the material while maintaining an efficient and effective system. This research found that the solutions are new dopants introduced into photorefractive lithium niobate to improve wavelength sensitivities and the use of a novel inexpensive diffuser that reduces the dynamic range and optical element quality requirements (which reduces the cost) while improving performance. A uniquely doped set of 12 lithium niobate crystals was specified and

Oxygen storage capacity and structural properties of Ni-doped LaMnO3 perovskites

International Nuclear Information System (INIS)

Ran, Rui; Wu, Xiaodong; Weng, Duan; Fan, Jun

2013-01-01

Graphical abstract: Dynamic OSC of (a) fresh and (b) aged LaMn 1−x Ni x O 3 perovskites (0.1 Hz). Aged condition: 1050 °C, 5 h, 7% steam in air. The LaMn 1−x Ni x O 3 perovskites exhibit considerable dynamic OSC in comparison to CeO 2 –ZrO 2 (CZ), even after 1050 °C hydrothermal ageing for 5 h. Highlights: •Ni-doped LaMnO 3 perovskites exhibit very large dynamic OSC and high oxygen storage rate. •Mn 4+ is favourable to the releasable oxygen. •Doping of Ni ions increase the Mn 4+ content and the oxygen vacancies. •Doping of Ni ions reduce the BO 6 distortion in the LaMnO 3 perovskites. -- Abstract: A series of Ni doped LaMnO 3 perovskites were prepared by a sol–gel method as oxygen storage materials. Powder X-ray diffraction (XRD), X-ray adsorption fine structure (XAFS), oxygen storage capacity (OSC) and H 2 -temperature program reduction (TPR) measurements were performed to investigate the OSC of the perovskites as well as the effects of Ni on the structural properties. The results showed that the Ni-doped LaMnO 3 perovskite exhibited very large dynamic OSC and high oxygen release rate, which provided a possibility to serve as an oxygen storage material candidate in three-way catalysts. The available oxygen species below 500 °C primarily originated from the redox reaction between Mn 4+ and Mn 3+ , and the more Mn 4+ were favourable to the releasable oxygen. The doping of appropriate Ni ions promoted the OSC of the LaMnO 3 perovskites by increasing the Mn 4+ content and adjusting the structural defects. On the other hand, the doped Ni ions could make the BO 6 distortion disappearing in the LaMnO 3 perovskites to reduce the lattice oxygen activity

Methane storage capacity of the early martian cryosphere

Science.gov (United States)

Lasue, Jeremie; Quesnel, Yoann; Langlais, Benoit; Chassefière, Eric

2015-11-01

Methane is a key molecule to understand the habitability of Mars due to its possible biological origin and short atmospheric lifetime. Recent methane detections on Mars present a large variability that is probably due to relatively localized sources and sink processes yet unknown. In this study, we determine how much methane could have been abiotically produced by early Mars serpentinization processes that could also explain the observed martian remanent magnetic field. Under the assumption of a cold early Mars environment, a cryosphere could trap such methane as clathrates in stable form at depth. The extent and spatial distribution of these methane reservoirs have been calculated with respect to the magnetization distribution and other factors. We calculate that the maximum storage capacity of such a clathrate cryosphere is about 2.1 × 1019-2.2 × 1020 moles of CH4, which can explain sporadic releases of methane that have been observed on the surface of the planet during the past decade (∼1.2 × 109 moles). This amount of trapped methane is sufficient for similar sized releases to have happened yearly during the history of the planet. While the stability of such reservoirs depends on many factors that are poorly constrained, it is possible that they have remained trapped at depth until the present day. Due to the possible implications of methane detection for life and its influence on the atmospheric and climate processes on the planet, confirming the sporadic release of methane on Mars and the global distribution of its sources is one of the major goals of the current and next space missions to Mars.

Complex Hydride Compounds with Enhanced Hydrogen Storage Capacity

Energy Technology Data Exchange (ETDEWEB)

Mosher, Daniel A.; Opalka, Susanne M.; Tang, Xia; Laube, Bruce L.; Brown, Ronald J.; Vanderspurt, Thomas H.; Arsenault, Sarah; Wu, Robert; Strickler, Jamie; Anton, Donald L.; Zidan, Ragaiy; Berseth, Polly

2008-02-18

The United Technologies Research Center (UTRC), in collaboration with major partners Albemarle Corporation (Albemarle) and the Savannah River National Laboratory (SRNL), conducted research to discover new hydride materials for the storage of hydrogen having on-board reversibility and a target gravimetric capacity of ≥ 7.5 weight percent (wt %). When integrated into a system with a reasonable efficiency of 60% (mass of hydride / total mass), this target material would produce a system gravimetric capacity of ≥ 4.5 wt %, consistent with the DOE 2007 target. The approach established for the project combined first principles modeling (FPM - UTRC) with multiple synthesis methods: Solid State Processing (SSP - UTRC), Solution Based Processing (SBP - Albemarle) and Molten State Processing (MSP - SRNL). In the search for novel compounds, each of these methods has advantages and disadvantages; by combining them, the potential for success was increased. During the project, UTRC refined its FPM framework which includes ground state (0 Kelvin) structural determinations, elevated temperature thermodynamic predictions and thermodynamic / phase diagram calculations. This modeling was used both to precede synthesis in a virtual search for new compounds and after initial synthesis to examine reaction details and options for modifications including co-reactant additions. The SSP synthesis method involved high energy ball milling which was simple, efficient for small batches and has proven effective for other storage material compositions. The SBP method produced very homogeneous chemical reactions, some of which cannot be performed via solid state routes, and would be the preferred approach for large scale production. The MSP technique is similar to the SSP method, but involves higher temperature and hydrogen pressure conditions to achieve greater species mobility. During the initial phases of the project, the focus was on higher order alanate complexes in the phase space

Thermodynamically Tuned Nanophase Materials for reversible Hydrogen storage

Energy Technology Data Exchange (ETDEWEB)

Ping Liu; John J. Vajo

2010-02-28

This program was devoted to significantly extending the limits of hydrogen storage technology for practical transportation applications. To meet the hydrogen capacity goals set forth by the DOE, solid-state materials consisting of light elements were developed. Many light element compounds are known that have high capacities. However, most of these materials are thermodynamically too stable, and they release and store hydrogen much too slowly for practical use. In this project we developed new light element chemical systems that have high hydrogen capacities while also having suitable thermodynamic properties. In addition, we developed methods for increasing the rates of hydrogen exchange in these new materials. The program has significantly advanced (1) the application of combined hydride systems for tuning thermodynamic properties and (2) the use of nanoengineering for improving hydrogen exchange. For example, we found that our strategy for thermodynamic tuning allows both entropy and enthalpy to be favorably adjusted. In addition, we demonstrated that using porous supports as scaffolds to confine hydride materials to nanoscale dimensions could improve rates of hydrogen exchange by > 50x. Although a hydrogen storage material meeting the requirements for commercial development was not achieved, this program has provided foundation and direction for future efforts. More broadly, nanoconfinment using scaffolds has application in other energy storage technologies including batteries and supercapacitors. The overall goal of this program was to develop a safe and cost-effective nanostructured light-element hydride material that overcomes the thermodynamic and kinetic barriers to hydrogen reaction and diffusion in current materials and thereby achieve > 6 weight percent hydrogen capacity at temperatures and equilibrium pressures consistent with DOE target values.

Hydrogen Storage Performance in Pd/Graphene Nanocomposites.

Science.gov (United States)

Zhou, Chunyu; Szpunar, Jerzy A

2016-10-05

We have developed a Pd-graphene nanocomposite for hydrogen storage. The spherically shaped Pd nanoparticles of 5-45 nm in size are homogeneously distributed over the graphene matrix. This new hydrogen storage system has favorable features like desirable hydrogen storage capacity, ambient conditions of hydrogen uptake, and low temperature of hydrogen release. At a hydrogen charging pressure of 50 bar, the material could yield a gravimetric density of 6.7 wt % in the 1% Pd/graphene nanocomposite. As we increased the applied pressure to 60 bar, the hydrogen uptake capacity reached 8.67 wt % in the 1% Pd/graphene nanocomposite and 7.16 wt % in the 5% Pd/graphene nanocomposite. This system allows storage of hydrogen in amounts that exceed the capacity of the gravimetric target announced by the U.S. Department of Energy (DOE).

Activity release during the dry storage of fuel assemblies

International Nuclear Information System (INIS)

Valentine, M.K.; Fettel, W.; Gunther, H.

1991-01-01

This paper reports that wet storage is the predominant storage method in the USA for spent fuel assemblies. Nevertheless, most utilities have stretched their storage capacities and several reactors will lose their full-core reserve in the 90's. A great variety of out-of-pool storage methods already exist, including the FUELSTOR vault-type dry storage concept. A FUELSTOR vault relies on double containment of the spent fuel (intact cladding as the primary containment and sealing of assemblies in canisters filled with an inert gas as the secondary containment) to reduce radiation levels at the outside wall of the vault to less than site boundary levels. Investigation of accident scenarios reveals that radiation release limits are only exceeded following complete failure of all canisters and simultaneous cladding breach for more than 40% of the rods (or for more than 1% of failed rods if massive fuel oxidation occurs following cladding failure). Such failures are considered highly improbable. Thus, it can be concluded that this type of dry storage is safe and individual canister monitoring is not required in the facility

Hydrogen storage in microwave-treated multi-walled carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Geng, Hong-Zhang [BK21 Physics Division, Department of Energy Science, Center for Nanotubes and Nanostructured Composites, Sungkyunkwan Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon 440-746 (Korea); School of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China); Kim, Tae Hyung; Lim, Seong Chu; Jeong, Hae-Kyung; Jin, Mei Hua; Jo, Young Woo; Lee, Young Hee [BK21 Physics Division, Department of Energy Science, Center for Nanotubes and Nanostructured Composites, Sungkyunkwan Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon 440-746 (Korea)

2010-03-15

Multiwalled carbon nanotubes (MWCNTs) treated by microwave and heat treatment were used for hydrogen storage. Their storage capacity was measured using a quadruple quartz crystal microbalance in a moisture-free chamber at room temperature and at relatively low pressure (0.5 MPa). Deuterium was also used to monitor the presence of moisture. The hydrogen storage capacity of the microwave-treated MWCNTs was increased to nearly 0.35 wt% over 0.1 wt% for the pristine sample and increased further to 0.4 wt%, with improved stability after subsequent heat-treatment. The increase in the storage capacity by the microwave treatment was mostly attributed to the introduction of micropore surfaces, while the stability improvement after the subsequent heat treatment was related to the removal of functional groups. We also propose a measurement method that eliminates the moisture effect by measuring the storage capacity with hydrogen and deuterium gas. (author)

Dry spent fuel storage licensing

International Nuclear Information System (INIS)

Sturz, F.C.

1995-01-01

In the US, at-reactor-site dry spent fuel storage in independent spent fuel storage installations (ISFSI) has become the principal option for utilities needing storage capacity outside of the reactor spent fuel pools. Delays in the geologic repository operational date at or beyond 2010, and the increasing uncertainty of the US Department of Energy's (DOE) being able to site and license a Monitored Retrievable Storage (MRS) facility by 1998 make at-reactor-site dry storage of spent nuclear fuel increasingly desirable to utilities and DOE to meet the need for additional spent fuel storage capacity until disposal, in a repository, is available. The past year has been another busy year for dry spent fuel storage licensing. The licensing staff has been reviewing 7 applications and 12 amendment requests, as well as participating in inspection-related activities. The authors have licensed, on a site-specific basis, a variety of dry technologies (cask, module, and vault). By using certified designs, site-specific licensing is no longer required. Another new cask has been certified. They have received one new application for cask certification and two amendments to a certified cask design. As they stand on the brink of receiving multiple applications from DOE for the MPC, they are preparing to meet the needs of this national program. With the range of technical and licensing options available to utilities, the authors believe that utilities can meet their need for additional spent fuel storage capacity for essentially all reactor sites through the next decade

Lithium ion storage between graphenes

Directory of Open Access Journals (Sweden)

Chan Yue

2011-01-01

Full Text Available Abstract In this article, we investigate the storage of lithium ions between two parallel graphene sheets using the continuous approximation and the 6-12 Lennard-Jones potential. The continuous approximation assumes that the carbon atoms can be replaced by a uniform distribution across the surface of the graphene sheets so that the total interaction potential can be approximated by performing surface integrations. The number of ion layers determines the major storage characteristics of the battery, and our results show three distinct ionic configurations, namely single, double, and triple ion forming layers between graphenes. The number densities of lithium ions between the two graphenes are estimated from existing semi-empirical molecular orbital calculations, and the graphene sheets giving rise to the triple ion layers admit the largest storage capacity at all temperatures, followed by a marginal decrease of storage capacity for the case of double ion layers. These two configurations exceed the maximum theoretical storage capacity of graphite. Further, on taking into account the charge-discharge property, the double ion layers are the most preferable choice for enhanced lithium storage. Although the single ion layer provides the least charge storage, it turns out to be the most stable configuration at all temperatures. One application of the present study is for the design of future high energy density alkali batteries using graphene sheets as anodes for which an analytical formulation might greatly facilitate rapid computational results.

Facile ultrasonic synthesis of CoO quantum dot/graphene nanosheet composites with high lithium storage capacity.

Science.gov (United States)

Peng, Chengxin; Chen, Bingdi; Qin, Yao; Yang, Shihe; Li, Chunzhong; Zuo, Yuanhui; Liu, Siyang; Yang, Jinhu

2012-02-28

In this paper, we report a facile ultrasonic method to synthesize well-dispersed CoO quantum dots (3-8 nm) on graphene nanosheets at room temperature by employing Co(4)(CO)(12) as cobalt precursor. The prepared CoO/graphene composites displayed high performance as an anode material for lithium-ion battery, such as high reversible lithium storage capacity (1592 mAh g(-1) after 50 cycles), high Coulombic efficiency (over 95%), excellent cycling stability, and high rate capability (1008 mAh g(-1) with a total retention of 77.6% after 50 cycles at a current density of 1000 mA g(-1), dramatically increased from the initial 50 mA g(-1)). The extraordinary performance arises from the structure advantages of the composites: the nanosized CoO quantum dots with high dispersity on conductive graphene substrates supply not only large quantity of accessible active sites for lithium-ion insertion but also good conductivity and short diffusion length for lithium ions, which are beneficial for high capacity and rate capability. Meanwhile, the isolated CoO quantum dots anchored tightly on the graphene nanosheets can effectively circumvent the volume expansion/contraction associated with lithium insertion/extraction during discharge/charge processes, which is good for high capacity as well as cycling stability. Moreover, regarding the anomalous behavior of capacity increase with cycles (activation effect) observed, we proposed a tentative hypothesis stressing the competition between the conductivity increase and the amorphorization of the composite electrodes during cycling in determining the trends of the capacity, in the hope to gain a fuller understanding of the inner working of the novel nanostructured electrode-based lithium-ion batteries.

Spent fuel storage requirements 1989--2020

International Nuclear Information System (INIS)

1989-10-01

Historical inventories of spent fuel are combined with Department of Energy (DOE) projections of future discharges from commercial nuclear reactors in the US to provide estimates of spent fuel storage requirements over the next 32 years, through the year 2020. The needs for storage capacity beyond that presently available in the pools are estimated. These estimates incorporate the maximum capacities within current and planned in-pool storage facilities and any planned transshipments of fuel to other reactors or facilities. Historical data through December 1988 are derived from the 1989 Form RW-859 data survey of nuclear utilities. Projected discharges through the end of reactor life are based on DOE estimates of future nuclear capacity, generation, and spent fuel discharges. 14 refs., 3 figs., 28 tabs

Chemical-clathrate hybrid hydrogen storage: storage in both guest and host.

Science.gov (United States)

Strobel, Timothy A; Kim, Yongkwan; Andrews, Gary S; Ferrell, Jack R; Koh, Carolyn A; Herring, Andrew M; Sloan, E Dendy

2008-11-12

Hydrogen storage from two independent sources of the same material represents a novel approach to the hydrogen storage problem, yielding storage capacities greater than either of the individual constituents. Here we report a novel hydrogen storage scheme in which recoverable hydrogen is stored molecularly within clathrate cavities as well as chemically in the clathrate host material. X-ray diffraction and Raman spectroscopic measurements confirm the formation of beta-hydroquinone (beta-HQ) clathrate with molecular hydrogen. Hydrogen within the beta-HQ clathrate vibrates at considerably lower frequency than hydrogen in the free gaseous phase and rotates nondegenerately with splitting comparable to the rotational constant. Compared with water-based clathrate hydrate phases, the beta-HQ+H2 clathrate shows remarkable stability over a range of p-T conditions. Subsequent to clathrate decomposition, the host HQ was used to directly power a PEM fuel cell. With one H2 molecule per cavity, 0.61 wt % hydrogen may be stored in the beta-HQ clathrate cavities. When this amount is combined with complete dehydrogenation of the host hydroxyl hydrogens, the maximum hydrogen storage capacity increases nearly 300% to 2.43 wt %.

Electrical Energy Storage Systems Feasibility; the Case of Terceira Island

Directory of Open Access Journals (Sweden)

Ana Rodrigues

2017-07-01

Full Text Available The Azores Regional Government, through the Sustainable Energy Action Plan for the Azorean Islands, assumed that by the year 2018, 60% of electricity would be generated from renewable energy sources. Nevertheless, by increasing renewable energy sources share in the electricity mix, peak energy that exceeds grid capacity cannot be used unless when considering energy storage systems. Therefore, this article aims at determining, among batteries and Pumped Hydro Systems, the most cost-effective energy storage system to deploy in Terceira Island, along with geothermal, wind, thermal and bio waste energy, while considering demand and supply constraints. It is concluded that a pumped hydro system sited in Serra do Morião-Nasce Água is the best option for storage of the excess generated energy when compared with batteries. However, further studies should analyze environmental constraints. It is demonstrated that by increasing the storage power capacity, a pumped hydro system improves its cost efficiency when compared with batteries. It is also demonstrated that, to ensure quality, economic feasibility, reliability and a reduction of external costs, it is preferable to replace fuel-oil by wind to generate electricity up to a conceivable technical limit, while building a pumped hydro system, or dumping the excess peak energy generated.

Simulation of CO2 Sequestration at Rock Spring Uplift, Wyoming: Heterogeneity and Uncertainties in Storage Capacity, Injectivity and Leakage

Energy Technology Data Exchange (ETDEWEB)

Deng, Hailin [Los Alamos National Laboratory; Dai, Zhenxue [Los Alamos National Laboratory; Jiao, Zunsheng [Wyoming State Geological Survey; Stauffer, Philip H. [Los Alamos National Laboratory; Surdam, Ronald C. [Wyoming State Geological Survey

2011-01-01

Many geological, geochemical, geomechanical and hydrogeological factors control CO{sub 2} storage in subsurface. Among them heterogeneity in saline aquifer can seriously influence design of injection wells, CO{sub 2} injection rate, CO{sub 2} plume migration, storage capacity, and potential leakage and risk assessment. This study applies indicator geostatistics, transition probability and Markov chain model at the Rock Springs Uplift, Wyoming generating facies-based heterogeneous fields for porosity and permeability in target saline aquifer (Pennsylvanian Weber sandstone) and surrounding rocks (Phosphoria, Madison and cap-rock Chugwater). A multiphase flow simulator FEHM is then used to model injection of CO{sub 2} into the target saline aquifer involving field-scale heterogeneity. The results reveal that (1) CO{sub 2} injection rates in different injection wells significantly change with local permeability distributions; (2) brine production rates in different pumping wells are also significantly impacted by the spatial heterogeneity in permeability; (3) liquid pressure evolution during and after CO{sub 2} injection in saline aquifer varies greatly for different realizations of random permeability fields, and this has potential important effects on hydraulic fracturing of the reservoir rock, reactivation of pre-existing faults and the integrity of the cap-rock; (4) CO{sub 2} storage capacity estimate for Rock Springs Uplift is 6614 {+-} 256 Mt at 95% confidence interval, which is about 36% of previous estimate based on homogeneous and isotropic storage formation; (5) density profiles show that the density of injected CO{sub 2} below 3 km is close to that of the ambient brine with given geothermal gradient and brine concentration, which indicates CO{sub 2} plume can sink to the deep before reaching thermal equilibrium with brine. Finally, we present uncertainty analysis of CO{sub 2} leakage into overlying formations due to heterogeneity in both the target saline

Developing new transportable storage casks for interim dry storage

Energy Technology Data Exchange (ETDEWEB)

Hayashi, K.; Iwasa, K.; Araki, K.; Asano, R. [Hitachi Zosen Diesel and Engineering Co., Ltd., Tokyo (Japan)

2004-07-01

Transportable storage metal casks are to be consistently used during transport and storage for AFR interim dry storage facilities planning in Japan. The casks are required to comply with the technical standards of regulations for both transport (hereinafter called ''transport regulation'') and storage (hereafter called ''storage regulation'') to maintain safety functions (heat transfer, containment, shielding and sub-critical control). In addition to these requirements, it is not planned in normal state to change the seal materials during storage at the storage facility, therefore it is requested to use same seal materials when the casks are transported after storage period. The dry transportable storage metal casks that satisfy the requirements have been developed to meet the needs of the dry storage facilities. The basic policy of this development is to utilize proven technology achieved from our design and fabrication experience, to carry out necessary verification for new designs and to realize a safe and rational design with higher capacity and efficient fabrication.

Underground gas storage in the World - Cedigaz survey

International Nuclear Information System (INIS)

Benquey, R.

2010-01-01

The 2010 edition of 'Underground Gas Storage in the World' provides an update to the previous survey released by CEDIGAZ in 2006. At that time, 610 underground gas storage (UGS) facilities were in operation worldwide, with a working capacity of 319 billion cubic metres (bcm). As of 1 January 2010, this number had reached 642 facilities with a working gas capacity of 333 bcm, or 10.8% of world gas consumption. By 2020, the global UGS demand is expected to grow at a pace of 3.3% per year, and according to the projects identified, more than 760 UGS sites could be active in the world with a total working capacity of approximately 465 bcm. In this survey, CEDIGAZ analyses the following trends which characterise the rapid development of underground gas storage in the world: - the strong dynamics of the European storage market, where 127 projects could add 75 bcm of working capacity by 2020, - the continued development of the UGS market in the United States (49 projects), encouraged by market-based rates allowed by the FERC, and rapid permitting processes, - the development of facilities in countries with little or no storage capacities at present, in Asia/Oceania, the C.I.S., and Eastern Europe in particular. This survey provides an analysis of the recent evolutions in the technic-economic aspects of the underground gas storage business, as well as an overview of the UGS markets and their developments in the world, country by country. A specific section is dedicated to the analysis of future UGS needs in Europe by 2020: - Technic-economic aspects of UGS: This part of the survey analyses the latest technical improvements and research axes in the field of underground gas storage. As it is more difficult to build greenfield storage facilities, a lot of work has been done to improve the performance and flexibility of existing storage sites. This section also deals with the evolution of investment and operational costs in storage over the last few years. Furthermore, the

Ice XVII as a Novel Material for Hydrogen Storage

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Leonardo del Rosso

2017-02-01

Full Text Available Hydrogen storage is one of the most addressed issues in the green-economy field. The latest-discovered form of ice (XVII, obtained by application of an annealing treatment to a H 2 -filled ice sample in the C 0 -phase, could be inserted in the energy-storage context due to its surprising capacity of hydrogen physisorption, when exposed to even modest pressure (few mbars at temperature below 40 K, and desorption, when a thermal treatment is applied. In this work, we investigate quantitatively the adsorption properties of this simple material by means of spectroscopic and volumetric data, deriving its gravimetric and volumetric capacities as a function of the thermodynamic parameters, and calculating the usable capacity in isothermal conditions. The comparison of ice XVII with materials with a similar mechanism of hydrogen adsorption like metal-organic frameworks shows interesting performances of ice XVII in terms of hydrogen content, operating temperature and kinetics of adsorption-desorption. Any application of this material to realistic hydrogen tanks should take into account the thermodynamic limit of metastability of ice XVII, i.e., temperatures below about 130 K.

Determination of Optimum Performance Strategy of Energy Storage in Power System

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Mohammad Hosein Ranjbari

2016-06-01

Full Text Available Determination of optimal capacity for today energy storages has been specially noticed. The delay in increasing storage production capacity is one of the applications for energy storage supplies in which utilization from energy storage supplies along with improvement in the power status at peak hours of consumption may postpone the demand for installation of a new power plant module. In this essay, the optimal capacity of energy storage is determined in order to reduce exploitation costs by second-order non linear programming. This method expresses this problem with a target quadratic function based on the produced power of units and capacity of energy storage supply. The requirements have been modeled as linear equality and inequality equations. The related constraints for produced power and incremental and decremental power ratio in generators have been considered as well.

Expansion of capacity of spent fuel pools and associated problems

International Nuclear Information System (INIS)

Francisco, J.L. De; Lopez-Cotarelo, J.; Ramos, J.M.

1978-01-01

Expanding the spent fuel storage pool capacity is a good solution for utilities facing the current shortage in fuel reprocessing capacity. The problems more likely to be found when expanding a spent fuel storage facility by using high density storage racks are reviewed. Basically three types of problems arise: 1) Problems related with the characteristics of the new facility. 2) Problems related with the works of expansion. 3) Problems related with the long term storage of large quantities of spent fuel. (author)

Cycling capacity recovery effect: A coulombic efficiency and post-mortem study

Science.gov (United States)

Wilhelm, Jörn; Seidlmayer, Stefan; Keil, Peter; Schuster, Jörg; Kriele, Armin; Gilles, Ralph; Jossen, Andreas

2017-10-01

The analysis of lithium-ion battery aging relies on correct differentiation between irreversible and reversible capacity changes. Anode overhang regions have been observed to influence Coulombic Efficiency (CE) measurements through lithium diffusion into and out of these areas, complicating precise capacity determination. This work presents an analysis of the extent of graphite anode overhang lithiation after calendar storage by means of local X-ray diffraction (XRD), CE measurements, and color change analysis. We found LiC12 lithiation of the anode overhang area after 20 month storage at 40 °C at high state of charge (SoC) and partial lithiation (LiC18) at medium SoC storage at 40 °C and 25 °C. Graphite color changes in the overhang areas are observed and consistent with the state of lithiation measured by XRD. Coulombic efficiencies greater than unity and increasing capacity during 1200 h of cycling are detected for high SoC storage cells. The capacity difference between high and low storage SoC batteries decreases by up to 40 mAh (3.6% of nominal capacity) after cycling compared to tests directly after storage. Consequently, the size of the anode overhang areas as well as the battery storage temperature and duration need to be considered in CE analysis and state of health assessment.

Study and project of the new rack with boron for storage of fuel elements burned in the IEA-R1 research reactor

International Nuclear Information System (INIS)

Rodrigues, Antonio Carlos Iglesias; Madi Filho, Tufic; Silva, Davilson Gomes da

2017-01-01

The IEA-R1 research reactor works 40h weekly with 4.5 Mw power. The storage rack for spent fuel elements has less than half of its initial capacity. Under these conditions (current conditions of reactor operation 32h weekly will have 3 spend fuel by year, then, approximately 3 utilization rate Positions/year). Thus, we will have only about six years of capacity for storage. Whereas the desired service life of the IEA-R1 is at least another 20 years, it will be necessary to increase the storage capacity of spent fuel. Hence, it is necessary to double the wet storage capacity (storage in the IEA-R1 reactor's pool). After reviewing the literature about materials available for use in the construction of the new storage rack with absorber of neutrons, the BoralcanTM (manufactured by 3TMhis) was chosen due to its properties. This work presents studies: (a) for the construction of new storages racks with double of the current capacity using the same place of current storages racks and (b) criticality analysis using the MCNP-5 code. Two American Nuclear Data Library were used: ENDF / B-VI and ENDF / B-VII, and the results obtained for each data bases were compared. These analyzes confirm the possibility of doubling the storage capacity of fuel elements burned in the same place occupied by the current storage rack attending to the IEA-R1 reactor needs and attending the safety requirements according to the National Nuclear Energy Commission - CNEN and the International Atomic Energy Agency (IAEA). To calculate the k eff were considered new fuel elements (maximum possible reactivity) used in full charge of the storage rack. With the results obtained in the simulation we can conclude that doubling the amount of racks for spent fuel elements are complied with safety limits established in the IAEA standards and CNEN of criticality (keff < 0.95). (author)

Study and project of the new rack with boron for storage of fuel elements burned in the IEA-R1 research reactor

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Antonio Carlos Iglesias; Madi Filho, Tufic; Silva, Davilson Gomes da, E-mail: acirodri@ipen.br, E-mail: tmfilho@usp.br, E-mail: dgsilva@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

2017-07-01

The IEA-R1 research reactor works 40h weekly with 4.5 Mw power. The storage rack for spent fuel elements has less than half of its initial capacity. Under these conditions (current conditions of reactor operation 32h weekly will have 3 spend fuel by year, then, approximately 3 utilization rate Positions/year). Thus, we will have only about six years of capacity for storage. Whereas the desired service life of the IEA-R1 is at least another 20 years, it will be necessary to increase the storage capacity of spent fuel. Hence, it is necessary to double the wet storage capacity (storage in the IEA-R1 reactor's pool). After reviewing the literature about materials available for use in the construction of the new storage rack with absorber of neutrons, the BoralcanTM (manufactured by 3TMhis) was chosen due to its properties. This work presents studies: (a) for the construction of new storages racks with double of the current capacity using the same place of current storages racks and (b) criticality analysis using the MCNP-5 code. Two American Nuclear Data Library were used: ENDF / B-VI and ENDF / B-VII, and the results obtained for each data bases were compared. These analyzes confirm the possibility of doubling the storage capacity of fuel elements burned in the same place occupied by the current storage rack attending to the IEA-R1 reactor needs and attending the safety requirements according to the National Nuclear Energy Commission - CNEN and the International Atomic Energy Agency (IAEA). To calculate the k{sub eff} were considered new fuel elements (maximum possible reactivity) used in full charge of the storage rack. With the results obtained in the simulation we can conclude that doubling the amount of racks for spent fuel elements are complied with safety limits established in the IAEA standards and CNEN of criticality (keff < 0.95). (author)

Design assessment for the Melton Valley Storage Tanks capacity increase at Oak Ridge National Laboratory under the Federal Facility Agreement, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1995-11-01

This project was initiated to find ways to increase storage capacity for the liquid low-level waste (LLLW) system at the Oak Ridge National Laboratory and satisfy the Federal Facility Agreement (FFA) requirement for the transfer of LLW from existing tank systems not in full FFA compliance

Changes in water-soluble vitamins and antioxidant capacity of fruit juice-milk beverages as affected by high-intensity pulsed electric fields (HIPEF) or heat during chilled storage.

Science.gov (United States)

Salvia-Trujillo, Laura; Morales-de la Peña, Mariana; Rojas-Graü, Alejandra; Martín-Belloso, Olga

2011-09-28

The effect of high-intensity pulsed electric fields (HIPEF) or thermal processes and refrigerated storage on water-soluble vitamins and antioxidant capacity of beverages containing fruit juices and whole (FJ-WM) or skim milk (FJ-SM) was assessed. Peroxidase (POD) and lipoxygenase (LOX) inactivation as well as color changes were also studied. High vitamin C retention was observed in HIPEF and thermally treated beverages, but a significant depletion of the vitamin during storage occurred, which was correlated with antioxidant capacity. HIPEF treatment did not affect the concentration of group B vitamins, which also remained constant over time, but thermally treated beverages showed lower riboflavin (vitamin B2) concentration. With regard to enzyme activity, thermal processing was more effective than HIPEF on POD and LOX inactivation. The color of the beverages was maintained after HIPEF processing and during storage. Consequently, HIPEF processing could be a feasible technology to attain beverages with fruit juices and milk with high vitamin content and antioxidant potential.

Impaired left ventricular systolic function reserve limits cardiac output and exercise capacity in HFpEF patients due to systemic hypertension.

Science.gov (United States)

Henein, Michael; Mörner, Stellan; Lindmark, Krister; Lindqvist, Per

2013-09-30

Heart failure (HF) patients with preserved left ventricular (LV) ejection fraction (EF) (HFpEF) due to systemic hypertension (SHT) are known to have limited exercise tolerance. Despite having normal EF at rest, we hypothesize that these patients have abnormal systolic function reserve limiting their exercise capacity. Seventeen patients with SHT (mean age 68 ± 9 years) but no valve disease and 14 healthy individuals (mean age of 65 ± 10 years) underwent resting and peak exercise echocardiography using conventional, tissue Doppler and speckle tracking techniques. The differences between resting and peak exercise values were also analyzed (Δ). Exercise capacity was determined as the workload divided by body surface area. Resting values for left atrial (LA) volume/BSA (r=-0.66, pexercise capacity. LVEF increased during exercise in normals (mean Δ EF=10 ± 8%) but failed to do so in patients (mean Δ EF=0.6 ± 9%, pexercise in patients, to the same extent as it did in normals (0.2 ± 0.2 vs. 0.6 ± 0.3 1/s, pexercise (Δ) in LV lateral wall systolic velocity from tissue Doppler (s') (0.71, pexercise capacity independent of changes in heart rate. HFpEF patients with hypertensive LV disease have significantly limited exercise capacity which is related to left atrial enlargement as well as compromised LV systolic function at the time of the symptoms. The limited myocardial systolic function reserve seems to be underlying important explanation for their limited exercise capacity. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Global distribution of grid connected electrical energy storage systems

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Katja Buss

2016-06-01

Full Text Available This article gives an overview of grid connected electrical energy storage systems worldwide, based on public available data. Technologies considered in this study are pumped hydroelectric energy storage (PHES, compressed air energy storage (CAES, sodium-sulfur batteries (NaS, lead-acid batteries, redox-flow batteries, nickel-cadmium batteries (NiCd and lithium-ion batteries. As the research indicates, the worldwide installed capacity of grid connected electrical energy storage systems is approximately 154 GW. This corresponds to a share of 5.5 % of the worldwide installed generation capacity. Furthermore, the article gives an overview of the historical development of installed and used storage systems worldwide. Subsequently, the focus is on each considered technology concerning the current storage size, number of plants and location. In summary it can be stated, PHES is the most commonly used technology worldwide, whereas electrochemical technologies are increasingly gaining in importance. Regarding the distribution of grid connected storage systems reveals the share of installed storage capacity is in Europe and Eastern Asia twice as high as in North America.

Assessment of Hanford burial grounds and interim TRU storage

International Nuclear Information System (INIS)

Geiger, J.F.; Brown, D.J.; Isaacson, R.E.

1977-08-01

A review and assessment is made of the Hanford low level solid radioactive waste management sites and facilities. Site factors considered favorable for waste storage and disposal are (1) limited precipitation, (2) a high deficiency of moisture in the underlying sediments (3) great depth to water table, all of which minimize radionuclide migration by water transport, and (4) high sorbtive capacity of the sediments. Facilities are in place for 20 year retrievable storage of transuranic (TRU) wastes and for disposal of nontransuranic radioactive wastes. Auxiliary facilities and services (utilities, roads, fire protection, shops, etc.) are considered adequate. Support staffs such as engineering, radiation monitoring, personnel services, etc., are available and are shared with other operational programs. The site and associated facilities are considered well suited for solid radioactive waste storage operations. However, recommendations are made for study programs to improve containment, waste package storage life, land use economy, retrievability and security of TRU wastes

Surface analytical investigations of the interaction between the getter material ZrCo and hydrogen and the influence of different contamination gases on the hydrogen storage capacity

International Nuclear Information System (INIS)

Glasbrenner, H.

1991-11-01

In this work the results of surface analytical investigations of the alloy ZrCo used for hydrogen storage as well as of the interaction of the alloy with hydrogen and various contamination gases present in a nuclear fusion reactor will be presented and discussed with respect to the application of ZrCo as getter material for tritium. The characterization of the ZrCo alloy showed that on the surface a stable ZrO 2 -layer is formed, which is, however, inhomogeneous. On the phase boundary solid / gas of samples exposed to hydrogen up to the stoichiometrical composition ZrCoH 2.8 a Co enrichment was observed. If the alloy ZrCo is activated before hydrogen take-up in the same way as other getter materials by heating under vacuum, the hydrogenation occurs faster and nearly complete. Zirconium is the alloy component responsible for the hydrogen storage. If a gas reacts nearly exclusively with the alloy component Co, a smaller decrease in the hydrogen storage capacity will be noticed. By exposition to CO and CO 2 mainly compounds with cobalt are formed. However, if the gas produces compounds with Zr like carbide, nitride, or oxide, the result is a strong decrease of the hydrogen storage capacity of the getter. (orig./MM) [de

Storage of phase-coded patterns via STDP in fully-connected and sparse network: a study of the network capacity

Directory of Open Access Journals (Sweden)

Silvia Scarpetta

2010-08-01

Full Text Available We study the storage and retrieval of phase-coded patterns as stable dynamical attractors in recurrent neural networks, for both an analog and a integrate-and-fire spiking model. The synaptic strength is determined by a learning rule based on spike-time-dependent plasticity, with an asymmetric time window depending on the relative timing between pre- and post-synaptic activity. We store multiple patterns and study the network capacity. For the analog model, we find that the network capacity scales linearly with the network size, and that both capacity and the oscillation frequency of the retrieval state depend on the asymmetry of the learning time window. In addition to fully-connected networks, we study sparse networks, where each neuron is connected only to a small number $zll N$ of other neurons. Connections can be short range, between neighboring neurons placed on a regular lattice, or long range, between randomly chosen pairs of neurons. We find that a small fraction of long range connections is able to amplify the capacity of the network. This imply that a small-world-network topology is optimal, as a compromise between the cost of long range connections and the capacity increase. Also in the spiking integrate and fire model the crucial result of storing and retrieval of multiple phase-coded patterns is observed. The capacity of the fully-connected spiking network is investigated, together with the relation between oscillation frequency of retrieval state and window asymmetry.

Concept of a large-capacity irradiated-fuel-reprocessing plant

International Nuclear Information System (INIS)

Buck, C.; Couture, J.; Issel, W.; Mamelle, J.

The processing of LWR fuels in recent years has run into difficulties due to the adaptation of the Purex process to these fuels with a high irradiation rate. This has led to development of new technological techniques. High-capacity plants should, in the future, limit their discharge of liquid and gaseous effluents to values comparable to those of nuclear electric stations. Investment costs necessary for processing the effluents and for temporary storage of the wastes are part of the total cost of these plants. However, the investments remain within acceptable limits. The 1500-ton/year plant presented is an example of what can be done in the 1980's

Storage method for spent fuel assembly