Sample records for sink capacity faster

  1. Low Carbon sink capacity of Red Sea mangroves

    KAUST Repository

    Almahasheer, Hanan


    Mangroves forests of Avicennia marina occupy about 135 km2 in the Red Sea and represent one of the most important vegetated communities in this otherwise arid and oligotrophic region. We assessed the soil organic carbon (C-org) stocks, soil accretion rates (SAR; mm y(-1)) and soil C-org sequestration rates (g C-org m(-2) yr(-1)) in 10 mangrove sites within four locations along the Saudi coast of the Central Red Sea. Soil C-org density and stock in Red Sea mangroves were among the lowest reported globally, with an average of 4 +/- 0.3 mg Corg cm(-3) and 43 +/- 5 Mg C-org ha(-1) (in 1 m-thick soils), respectively. Sequestration rates of C-org, estimated at 3 +/- 1 and 15 +/- 1 g C-org m(-2) yr(-1) for the long (millennia) and short (last century) temporal scales, respectively, were also relatively low compared to mangrove habitats from more humid bioregions. In contrast, the accretion rates of Central Red Sea mangroves soils were within the range reported for global mangrove forests. The relatively low C-org sink capacity of Red Sea mangroves could be due to the extreme environmental conditions such as low rainfall, nutrient limitation and high temperature, reducing the growth rates of the mangroves and increasing soil respiration rates.

  2. Experimental investigation of a PCM-HP heat sink on its thermal performance and anti-thermal-shock capacity for high-power LEDs

    International Nuclear Information System (INIS)

    Wu, Yuxuan; Tang, Yong; Li, Zongtao; Ding, Xinrui; Yuan, Wei; Zhao, Xuezhi; Yu, Binhai


    Highlights: • A phase-change material (PCM) base heat pipe heat sink (PCM-HP heat sink) is designed. • The PCM-HP heat sink can significantly lower the LED heating rate and temperature. • The PCM-HP heat sink achieves a best anti-thermal-shock capacity in LED cyclic working modes. - Abstract: High-power LEDs demonstrate a number of benefits compared with conventional incandescent lamps and fluorescent lamps, including a longer lifetime, higher brightness and lower power consumption. However, owing to their severe high heat flux, it is difficult to develop effective thermal management of high-power LEDs, especially under cyclic working modes, which cause serious periodic thermal stress and limit further development. Focusing on the above problem, this paper designed a phase-change material (PCM) base heat pipe heat sink (PCM-HP heat sink) that consists of a PCM base, adapter plate, heat pipe and finned radiator. Different parameters, such as three types of interior materials to fill the heat sink, three LED power inputs and eight LED cyclic working modes, were separately studied to investigate the thermal performance and anti-thermal-shock capacity of the PCM-HP heat sink. The results show that the PCM-HP heat sink possesses remarkable thermal performance owing to the reduction of the LED heating rate and peak temperature. More importantly, an excellent anti-thermal-shock capacity of the PCM-HP heat sink is also demonstrated when applied in LED cyclic working modes, and this capacity demonstrates the best range.

  3. Determining the capacity and rate of advance of tunneling scoops during the sinking of shafts

    Energy Technology Data Exchange (ETDEWEB)

    Durov, E.M.


    Methods for calculating parameters and selecting tunneling rigs for deepening mine shafts and for determining their rate of advance are outlined. The output according to type of rig, scoop capacity and range of rate of advance in the shaft are determined firstly and then a graph of output in relation to the change of maximum rates of advance is constructed. The desired productivity is determined on the basis of output per working shift in loose soil. Having determined scoop capacity and rate of advance, the remaining parameters of the excavation may be determined.

  4. Effect of environmental factors (wave exposure and depth) and anthropogenic pressure in the C sink capacity of Posidonia oceanica meadows

    KAUST Repository

    Mazarrasa, Inés


    Seagrass are among the most important natural carbon sinks on Earth with Posidonia oceanica (Mediterranean Sea) considered as the most relevant species. Yet, the number of direct measurements of organic carbon burial rates in P. oceanica is still scarce and the effect of local environmental factors remains largely unexplored. In addition, P. oceanica meadows are declining due to the increase in anthropogenic pressure in coastal areas during the last century. The aim of this study is to assess the recent carbon sink capacity of P. oceanica and particularly the effect of human pressure and two environmental factors, water depth and exposure to wave energy (based on a fetch index), on the carbon burial rate since 1900. We conducted an extensive survey of sediment cores in meadows distributed across a gradient of depth, fetch, and human pressure around The Balearic Islands. Sediment and carbon accumulation rates were obtained from 210Pb concentrations profiles. Top-30 centimeters carbon stocks (6.1 ± 1.4 kg C m−2) and burial rates (26 ± 6 g C m−2 yr1) varied up to fivefold across meadows. No significant effect of water depth in carbon burial rates was observed. Although fetch was significantly correlated with sediment mean grain size, confirming the effect of wave exposure in the patterns of sedimentation, fetch alone could not explain the differences in carbon burial rates among the meadows examined. Human pressure affected carbon burial rates, leading to increased rates since the onset of the rise in anthropogenic pressure, particularly so in sheltered meadows supporting high human pressure.

  5. Wink Sink

    Energy Technology Data Exchange (ETDEWEB)

    Baumgardner, R.W. Jr.


    The Wink Sink formed on June 3, l980. Inferred precursor of the sinkhole was a solution cavity in the Permian Salado Formation formed either by natural dissolution or by water flow in an abandoned oil well. Correlation of well logs in the area indicates that the Salado Formation contains several dissolution zones. Dissolution in the middle of the Salado evaporite sequence may have resulted from ground-water flow along fractured anhydrite interbeds. The Wink Sink lies directly above the Permian Capitan reef on the margin of a natural salt dissolution trough. Other natural collapse features overlie the reef to the north. Hydraulic head of water in the reef is higher than the elevation of the Salado Formation but lower than the head in the Triassic Santa Rosa Sandstone, a near-surface freshwater aquifer. Fracture or cavernous permeability occurs above, within, and below the Salado Formation. Consequently, a brine-density flow may be operating: relatively fresh water moves upward through fractures under artesian pressure and dissolves salt; the denser brine moves downward under gravity flow. Alternatively, downward flow of water from freshwater aquifers above the salt may have caused dissolution. An oil well drilled into the Permian Yates Formation (with the aid of nitroglycerine) in 1928 was located within the sinkhole. The well initially produced about 80% saline water from the Permian Tansill Formation, which directly underlies the Salado. About 600 ft of casing was removed from the well when it was plugged and abandoned in 1964.

  6. Writing faster Python

    CERN Multimedia

    CERN. Geneva


    Did you know that Python preallocates integers from -5 to 257 ? Reusing them 1000 times, instead of allocating memory for a bigger integer, can save you a couple of milliseconds of code’s execution time. If you want to learn more about this kind of optimizations then, … well, probably this presentation is not for you :) Instead of going into such small details, I will talk about more "sane" ideas for writing faster code. After a very brief overview of how to optimize Python code (rule 1: don’t do this; rule 2: don’t do this yet; rule 3: ok, but what if I really want to do this ?), I will show simple and fast ways of measuring the execution time and finally, discuss examples of how some code structures could be improved. You will see: - What is the fastest way of removing duplicates from a list - How much faster your code is when you reuse the built-in functions instead of trying to reinvent the wheel - What is faster than the good ol’ for loop - If the lookup is faster in a list or a set (and w...

  7. Preparing for faster filling

    CERN Multimedia

    CERN Bulletin


    Following the programmed technical stop last week, operators focussed on preparing the machine for faster filling, which includes multibunch injection and a faster pre-cycle phase.   The LHC1 screen shot during the first multibunch injection operation. The LHC operational schedule incorporates a technical stop for preventive maintenance roughly every six weeks of stable operation, during which several interventions on the various machines are carried out. Last week these included the replacement of a faulty magnet in the SPS pre-accelerator, which required the subsequent re-setting of the system of particle extraction and transfer to the LHC. At the end of last week, all the machines were handed back for operation and work could start on accommodating all the changes made into the complex systems in order for normal operation to be resumed. These ‘recovery’ operations continued through the weekend and into this week. At the beginning of this week, operators succeeded in pro...

  8. Longer - Faster - Purer

    CERN Document Server

    Caroline Duc


    The MR-ToF-MS, a new ion trap, has been integrated into ISOLTRAP, the experiment that performs accurate mass measurements on short-lived nuclides produced at ISOLDE. When used as a mass separator and spectrometer, it extends ISOLTRAP’s experimental reach towards the limits of nuclear stability.   Susanne Kreim, the ISOLTRAP local group leader at CERN in front of a part of the ISOLTRAP device. When mass measurement experiments like ISOLTRAP* are placed in an on-line radioactive ion-beam facility they face a major challenge: the efficient and fast transfer of the nuclide of interest to the location where the mass measurement is performed. The biggest yield of one selected nuclide, without contaminants, needs to be transferred to the set-up as quickly as possible in order to measure its mass with the greatest precision. Recently, the ISOLTRAP collaboration installed a new device that provides a faster separation of isobars.** It has significantly improved ISOLTRAP’s purificat...

  9. Sinking towards destiny: High throughput measurement of phytoplankton sinking rates through time-resolved fluorescence plate spectroscopy. (United States)

    Bannon, Catherine C; Campbell, Douglas A


    Diatoms are marine primary producers that sink in part due to the density of their silica frustules. Sinking of these phytoplankters is crucial for both the biological pump that sequesters carbon to the deep ocean and for the life strategy of the organism. Sinking rates have been previously measured through settling columns, or with fluorimeters or video microscopy arranged perpendicularly to the direction of sinking. These side-view techniques require large volumes of culture, specialized equipment and are difficult to scale up to multiple simultaneous measures for screening. We established a method for parallel, large scale analysis of multiple phytoplankton sinking rates through top-view monitoring of chlorophyll a fluorescence in microtitre well plates. We verified the method through experimental analysis of known factors that influence sinking rates, including exponential versus stationary growth phase in species of different cell sizes; Thalassiosira pseudonana CCMP1335, chain-forming Skeletonema marinoi RO5A and Coscinodiscus radiatus CCMP312. We fit decay curves to an algebraic transform of the decrease in fluorescence signal as cells sank away from the fluorometer detector, and then used minimal mechanistic assumptions to extract a sinking rate (m d-1) using an RStudio script, SinkWORX. We thereby detected significant differences in sinking rates as larger diatom cells sank faster than smaller cells, and cultures in stationary phase sank faster than those in exponential phase. Our sinking rate estimates accord well with literature values from previously established methods. This well plate-based method can operate as a high throughput integrative phenotypic screen for factors that influence sinking rates including macromolecular allocations, nutrient availability or uptake rates, chain-length or cell size, degree of silification and progression through growth stages. Alternately the approach can be used to phenomically screen libraries of mutants.

  10. Sink-oriented Dynamic Location Service Protocol for Mobile Sinks with an Energy Efficient Grid-Based Approach

    Directory of Open Access Journals (Sweden)

    Hyunseung Choo


    Full Text Available Sensor nodes transmit the sensed information to the sink through wireless sensor networks (WSNs. They have limited power, computational capacities and memory. Portable wireless devices are increasing in popularity. Mechanisms that allow information to be efficiently obtained through mobile WSNs are of significant interest. However, a mobile sink introduces many challenges to data dissemination in large WSNs. For example, it is important to efficiently identify the locations of mobile sinks and disseminate information from multi-source nodes to the multi-mobile sinks. In particular, a stationary dissemination path may no longer be effective in mobile sink applications, due to sink mobility. In this paper, we propose a Sink-oriented Dynamic Location Service (SDLS approach to handle sink mobility. In SDLS, we propose an Eight-Direction Anchor (EDA system that acts as a location service server. EDA prevents intensive energy consumption at the border sensor nodes and thus provides energy balancing to all the sensor nodes. Then we propose a Location-based Shortest Relay (LSR that efficiently forwards (or relays data from a source node to a sink with minimal delay path. Our results demonstrate that SDLS not only provides an efficient and scalable location service, but also reduces the average data communication overhead in scenarios with multiple and moving sinks and sources.

  11. Sink-oriented Dynamic Location Service Protocol for Mobile Sinks with an Energy Efficient Grid-Based Approach. (United States)

    Jeon, Hyeonjae; Park, Kwangjin; Hwang, Dae-Joon; Choo, Hyunseung


    Sensor nodes transmit the sensed information to the sink through wireless sensor networks (WSNs). They have limited power, computational capacities and memory. Portable wireless devices are increasing in popularity. Mechanisms that allow information to be efficiently obtained through mobile WSNs are of significant interest. However, a mobile sink introduces many challenges to data dissemination in large WSNs. For example, it is important to efficiently identify the locations of mobile sinks and disseminate information from multi-source nodes to the multi-mobile sinks. In particular, a stationary dissemination path may no longer be effective in mobile sink applications, due to sink mobility. In this paper, we propose a Sink-oriented Dynamic Location Service (SDLS) approach to handle sink mobility. In SDLS, we propose an Eight-Direction Anchor (EDA) system that acts as a location service server. EDA prevents intensive energy consumption at the border sensor nodes and thus provides energy balancing to all the sensor nodes. Then we propose a Location-based Shortest Relay (LSR) that efficiently forwards (or relays) data from a source node to a sink with minimal delay path. Our results demonstrate that SDLS not only provides an efficient and scalable location service, but also reduces the average data communication overhead in scenarios with multiple and moving sinks and sources.

  12. Regulation of assimilate import into sink organs: Update on molecular drivers of sink strength

    Directory of Open Access Journals (Sweden)

    Saadia eBihmidine


    Full Text Available Recent developments have altered our view of molecular mechanisms that determine sink strength, defined here as the capacity of non-photosynthetic structures to compete for import of photoassimilates. We review new findings from diverse systems, including stems, seeds, flowers, and fruits. An important advance has been the identification of new transporters and facilitators with major roles in the accumulation and equilibration of sugars at a cellular level. Exactly where each exerts its effect varies among systems. Sugarcane and sweet sorghum stems, for example, both accumulate high levels of sucrose, but may do so via different paths. The distinction is central to strategies for targeted manipulation of sink strength using transporter genes, and shows the importance of system-specific analyses. Another major advance has been the identification of deep hypoxia as a feature of normal grain development. This means that molecular drivers of sink strength in endosperm operate in very low oxygen levels, and under metabolic conditions quite different than previously assumed. Successful enhancement of sink strength has nonetheless been achieved in grains by up-regulating genes for starch biosynthesis. Additionally, our understanding of sink strength is enhanced by awareness of the dual roles played by invertases (INV, not only in sucrose metabolism, but also in production of the hexose sugar signals that regulate cell-cycle and cell-division programs. These contributions of INV to cell expansion and division prove to be vital for establishment of young sinks ranging from flowers to fruit. Since INV genes are themselves sugar-responsive feast genes, they can mediate a feed-forward enhancement of sink strength when assimilates are abundant. Greater overall productivity and yield have thus been attained in key instances, indicating that even broader enhancements may be achievable as we discover the detailed molecular mechanisms that drive sink strength

  13. Zero bugs and program faster

    CERN Document Server

    Thompson, Kate


    A book about programming, improving skill, and avoiding mistakes. The author spent two years researching every bug avoidance technique she could find. This book contains the best of them. If you want to program faster, with fewer bugs, and write more secure code, buy this book! "This is the best book I have ever read." - Anonymous reviewer "Four score and seven years ago this book helped me debug my server code." -Abraham Lincoln "Would my Javascript have memory leaks without this book? Would fishes fly without water?" -Socrates "This book is the greatest victory since the Spanish Armada, and the best about programming." -Queen Elizabeth

  14. Energies and carbon sinks

    International Nuclear Information System (INIS)

    Riedacker, A.


    The Kyoto Protocol puts a lot of emphasis on carbon sinks. This emphasis almost obliterates the other potential contributions of biomass in the fight against climatic changes and toward sustainable development. Biomass represents an infinite supply of renewable energy sources which do not increase the levels of carbon in the atmosphere, contribute to energy savings resulting from the use of wood rather than other materials, the sustainable management of soils, the fight against drought, agroforestry from which the production of foods depends, the mitigating of certain extreme climatic occurrences and the protection of dams from increased silting. The industrial revolution contributed to the increase in greenhouse gas emissions. When discussing some of the finer points of the Kyoto Protocol, the focus was placed on carbon sinks. The author indicates that the biomass cycle had to be considered, both in situ and ex situ. Details to this effect are provided, and a section dealing with greenhouse gases other than carbon must be taken into account. The rural environment must be considered globally. The author indicates that in the future, the emissions resulting from the transportation of agricultural products will have to be considered. Within the realm of the policies on sustainable development, the fight against climatic change represents only one aspect. In arid and semi-arid regions, one must take into account meeting the energy needs of the populations, the fight against drought and the preservation of biodiversity. The planting of trees offers multiple advantages apart from being a carbon sink: roughage, wood for burning, protection of soils, etc. A few examples are provided. 8 refs., 3 figs

  15. Sinks as integrative elements of the anthropogenic metabolism (United States)

    Kral, Ulrich; Brunner, Paul H.


    The anthropogenic metabolism is an open system requiring exchange of materials and energy between the anthroposphere and the environment. Material and energy flows are taken from nature and become utilized by men. After utilization, the materials either remain in the anthroposphere as recycling products, or they leave the anthroposphere as waste and emission flows. To accommodate these materials without jeopardizing human and environmental health, limited natural sinks are available; thus, man-made sinks have to be provided where natural sinks are missing or overloaded. The oral presentation (1) suggests a coherent definition of the term "sink", encompassing natural and man-made processes, (2) presents a framework to analyse and evaluate anthropogenic material flows to sinks, based on the tool substance flow analysis and impact assessment methodology, and (3) applies the framework in a case study approach for selected substances such as Copper and Lead in Vienna and Perfluorooctane sulfonate in Switzerland. Finally, the numeric results are aggregated in terms of a new indicator that specifies on a regional scale which fractions of anthropogenic material flows to sinks are acceptable. The following results are obtained: In Vienna, 99% of Cu flows to natural and man-made sinks are in accordance with accepted standards. However, the 0.7% of Cu entering urban soils and the 0.3% entering receiving waters surpass the acceptable level. In the case of Pb, 92% of all flows into sinks prove to be acceptable, but 8% are disposed of in local landfills with limited capacity. For PFOS, 96% of all flows into sinks are acceptable. 4% cannot be evaluated due to a lack of normative criteria, despite posing a risk for human health and the environment. The case studies corroborate the need and constraints of sinks to accommodate inevitable anthropogenic material flows.

  16. Long-term decline of the Amazon carbon sink. (United States)

    Brienen, R J W; Phillips, O L; Feldpausch, T R; Gloor, E; Baker, T R; Lloyd, J; Lopez-Gonzalez, G; Monteagudo-Mendoza, A; Malhi, Y; Lewis, S L; Vásquez Martinez, R; Alexiades, M; Álvarez Dávila, E; Alvarez-Loayza, P; Andrade, A; Aragão, L E O C; Araujo-Murakami, A; Arets, E J M M; Arroyo, L; Aymard C, G A; Bánki, O S; Baraloto, C; Barroso, J; Bonal, D; Boot, R G A; Camargo, J L C; Castilho, C V; Chama, V; Chao, K J; Chave, J; Comiskey, J A; Cornejo Valverde, F; da Costa, L; de Oliveira, E A; Di Fiore, A; Erwin, T L; Fauset, S; Forsthofer, M; Galbraith, D R; Grahame, E S; Groot, N; Hérault, B; Higuchi, N; Honorio Coronado, E N; Keeling, H; Killeen, T J; Laurance, W F; Laurance, S; Licona, J; Magnussen, W E; Marimon, B S; Marimon-Junior, B H; Mendoza, C; Neill, D A; Nogueira, E M; Núñez, P; Pallqui Camacho, N C; Parada, A; Pardo-Molina, G; Peacock, J; Peña-Claros, M; Pickavance, G C; Pitman, N C A; Poorter, L; Prieto, A; Quesada, C A; Ramírez, F; Ramírez-Angulo, H; Restrepo, Z; Roopsind, A; Rudas, A; Salomão, R P; Schwarz, M; Silva, N; Silva-Espejo, J E; Silveira, M; Stropp, J; Talbot, J; ter Steege, H; Teran-Aguilar, J; Terborgh, J; Thomas-Caesar, R; Toledo, M; Torello-Raventos, M; Umetsu, R K; van der Heijden, G M F; van der Hout, P; Guimarães Vieira, I C; Vieira, S A; Vilanova, E; Vos, V A; Zagt, R J


    Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.

  17. The role of plantation sinks

    International Nuclear Information System (INIS)

    Read, Peter


    In this paper it is argued that in the long term biofuel should play a significant role in global climate policy. Recent technological developments, as well as sustainable development criteria, would favour growing biofuel in community- scale plantations in developing countries. It is also pointed out that the lead times involved in growing biofuels are so great that the inclusion of biofuel plantation sinks in the CDM for the first commitment period would be desirable. It is suggested that to meet opposition to the inclusion of plantation sinks in the first commitment period plantation, sinks should be linked to biofuels technology development and production, and a biofuels obligation for plantation sink projects in the CDM should be established. (Author)

  18. Sinking coastal cities (United States)

    Erkens, Gilles; Bucx, Tom; Dam, Rien; De Lange, Ger; Lambert, John


    In many coastal and delta cities land subsidence now exceeds absolute sea level rise up to a factor of ten. Without action, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal cities will sink below sea level. Land subsidence increases flood vulnerability (frequency, inundation depth and duration of floods), with floods causing major economic damage and loss of lives. In addition, differential land movement causes significant economic losses in the form of structural damage and high maintenance costs. This effects roads and transportation networks, hydraulic infrastructure - such as river embankments, sluice gates, flood barriers and pumping stations -, sewage systems, buildings and foundations. The total damage worldwide is estimated at billions of dollars annually. Excessive groundwater extraction after rapid urbanization and population growth is the main cause of severe land subsidence. In addition, coastal cities are often faced with larger natural subsidence, as they are built on thick sequences of soft soil. Because of ongoing urbanization and population growth in delta areas, in particular in coastal megacities, there is, and will be, more economic development in subsidence-prone areas. The impacts of subsidence are further exacerbated by extreme weather events (short term) and rising sea levels (long term).Consequently, detrimental impacts will increase in the near future, making it necessary to address subsidence related problems now. Subsidence is an issue that involves many policy fields, complex technical aspects and governance embedment. There is a need for an integrated approach in order to manage subsidence and to develop appropriate strategies and measures that are effective and efficient on both the short and long term. Urban (ground)water management, adaptive flood risk management and related spatial planning strategies are just examples of the options available. A major rethink is needed to deal with the 'hidden' but urgent

  19. FASTER Test Reactor Preconceptual Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Grandy, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Belch, H. [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, A. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Heidet, F. [Argonne National Lab. (ANL), Argonne, IL (United States); Hill, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hoffman, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Jin, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Mohamed, W. [Argonne National Lab. (ANL), Argonne, IL (United States); Moisseytsev, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Passerini, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Sienicki, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Sumner, T. [Argonne National Lab. (ANL), Argonne, IL (United States); Vilim, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hayes, S. [Argonne National Lab. (ANL), Argonne, IL (United States)


    The FASTER test reactor plant is a sodium-cooled fast spectrum test reactor that provides high levels of fast and thermal neutron flux for scientific research and development. The 120MWe FASTER reactor plant has a superheated steam power conversion system which provides electrical power to a local grid allowing for recovery of operating costs for the reactor plant.

  20. FASTER test reactor preconceptual design report summary

    Energy Technology Data Exchange (ETDEWEB)

    Grandy, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Belch, H. [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Heidet, F. [Argonne National Lab. (ANL), Argonne, IL (United States); Hill, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hoffman, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Jin, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Mohamed, W. [Argonne National Lab. (ANL), Argonne, IL (United States); Moisseytsev, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Passerini, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Sienicki, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Sumner, T. [Argonne National Lab. (ANL), Argonne, IL (United States); Vilim, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hayes, Steven [Argonne National Lab. (ANL), Argonne, IL (United States)


    The FASTER reactor plant is a sodium-cooled fast spectrum test reactor that provides high levels of fast and thermal neutron flux for scientific research and development. The 120MWe FASTER reactor plant has a superheated steam power conversion system which provides electrical power to a local grid allowing for recovery of operating costs for the reactor plant.

  1. Ocean carbon sinks and international climate policy

    NARCIS (Netherlands)

    Rehdanz, K.; Tol, R.S.J.; Wetzel, P.


    Terrestrial vegetation sinks have entered the Kyoto Protocol as offsets for anthropogenic greenhouse gas emissions, but ocean sinks have escaped attention. Ocean sinks are as unexplored and uncertain as were the terrestrial sinks at the time of negotiation of the Kyoto Protocol. It is not unlikely

  2. Section 2: Assessment of local and regional carbon sources and sinks (United States)

    This section of the book discusses assessment of local and regional carbon sinks. The chapters of Section 1 discuss the increase in the global CO2 concentration, the aggregate sum of all local and regional carbon sources, whereas those of Section 2 focus mostly on sinks: The terrestrial sinks of soils, grasses, and forest can become sources of CO2 when those sinks die or burn (plants) or erode (soils). Likewise, as ocean temperatures increase, the solubility of CO2 in the seas decreases, reducing the capacity of that sink. Additionally, although the terrestrial sequestration literature provides a wide range of new options, forest management and agricultural soils management—as Perry et al. and Mikhailova et al., respectively, discuss—can increase carbon storage capacity without a great deal of new research.

  3. How Low Can You Sink?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 2. How Low Can You Sink? In Search of Global Minima. Vivek S Borkar. General Article Volume 2 ... Author Affiliations. Vivek S Borkar1. Department of Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India ...

  4. Sink-source and sink-sink relations during reproductive development in Lolium perenne L.

    NARCIS (Netherlands)

    Warringa, J.W.; Marinissen, M.J.


    In greenhouse pot trials, L. perenne cv. Barlet plants were labelled with 13C at regular intervals from main spike emergence onwards in order to identify and measure the activity of source and sink organs during seed formation. The source activity of the various tiller groups within the plant

  5. Multi-lead heat sink (United States)

    Roose, L.D.


    The disclosure relates to a heat sink used to protect integrated circuits from the heat resulting from soldering them to circuit boards. A tubular housing contains a slidable member which engages somewhat inwardly extending connecting rods, each of which is rotatably attached at one end to the bottom of the housing. The other end of each rod is fastened to an expandable coil spring loop. As the member is pushed downward in the housing, its bottom edge engages and forces outward the connecting rods, thereby expanding the spring so that it will fit over an integrated circuit. After the device is in place, the member is slid upward and the spring contracts about the leads of the integrated circuit. Soldering is now conducted and the spring absorbs excess heat therefrom to protect the integrated circuit. The placement steps are repeated in reverse order to remove the heat sink for use again.

  6. Tropical Wetlands as Carbon Sinks (United States)

    Jones, M. B.; Saunders, M.


    This presentation focuses on the tropical wetlands of sub-Saharan Africa. These are an understudied ecosystem in which large emergent grasses and sedges normally dominate and which have the potential to sequester significant amounts of carbon. Measurements of Net Primary Production of these wetlands show that they are some of the highest values recorded for any ecosystem. We have used eddy covariance to measure Net Ecosystem Exchange of pristine and disturbed wetlands and show that pristine systems can have sink strengths as strong as tropical forests while disturbed systems that have been reclaimed for agricultural purposes have a very much reduced carbon sink activity and may be net carbon sources. The management issues surrounding the use of these wetlands illustrate a direct conflict between the production of food crops for the local population and the maintenance of carbon sequestration as an ecosystem service.

  7. Modelling fungal sink competitiveness with grains for assimilates in wheat infected by a biotrophic pathogen (United States)

    Bancal, Marie-Odile; Hansart, Amandine; Sache, Ivan; Bancal, Pierre


    Background and Aims Experiments have shown that biotrophic fungi divert assimilates for their growth. However, no attempt has been made either to account for this additional sink or to predict to what extent it competes with both grain filling and plant reserve metabolism for carbon. Fungal sink competitiveness with grains was quantified by a mixed experimental–modelling approach based on winter wheat infected by Puccinia triticina. Methods One week after anthesis, plants grown under controlled conditions were inoculated with varying loads. Sporulation was recorded while plants underwent varying degrees of shading, ensuring a range of both fungal sink and host source levels. Inoculation load significantly increased both sporulating area and rate. Shading significantly affected net assimilation, reserve mobilization and sporulating area, but not grain filling or sporulation rates. An existing carbon partitioning (source–sink) model for wheat during the grain filling period was then enhanced, in which two parameters characterize every sink: carriage capacity and substrate affinity. Fungal sink competitiveness with host sources and sinks was modelled by representing spore production as another sink in diseased wheat during grain filling. Key Results Data from the experiment were fitted to the model to provide the fungal sink parameters. Fungal carriage capacity was 0·56 ± 0·01 µg dry matter °Cd−1 per lesion, much less than grain filling capacity, even in highly infected plants; however, fungal sporulation had a competitive priority for assimilates over grain filling. Simulation with virtual crops accounted for the importance of the relative contribution of photosynthesis loss, anticipated reserve depletion and spore production when light level and disease severity vary. The grain filling rate was less reduced than photosynthesis; however, over the long term, yield loss could double because the earlier reserve depletion observed here would shorten the

  8. Multi-objective optimization of electronics heat sinks cooled by natural convection (United States)

    Lampio, K.; Karvinen, R.


    Fins and fin arrays with constant temperature at the fin base have known solutions for natural convection. However, in practical applications, no simple solution exists for maximum temperature of heat sink with many heat dissipating components located at the base plate. A calculation model is introduced here to solve this practical problem without time consuming CFD modelling of fluid flow and heat transfer. Solutions with the new model are compared with some simple analytical and CFD solutions to prove that the results are accurate enough for practical applications. Seminal here is that results are obtained many orders of magnitude faster than with CFD. This much shorter calculation time scale makes the model well suited for multi-objective optimization in, e.g., simultaneous minimization of heat sink maximum temperature, size, and mass. An optimization case is presented in which heat sink mass and size are significantly reduced over those of the original reference heat sink.

  9. Can Light Travel Faster than Light?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 11. Can Light Travel Faster than Light? Supurna Sinha. Research News Volume 5 Issue 11 November 2000 pp 90-93. Fulltext. Click here to view fulltext PDF. Permanent link: ...

  10. Faster, bigger, easier; Schneller, groesser, einfacher

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, Anja


    Time is money, so solar farms of the megawatt power range must get connected to the grid ever faster. This is achieved, among others, by clever new ways of fastening solar modules. Further, GPS-controlled ramming robots and giant modules are to speed up construction of solar cell arrays in open fields. (orig.)

  11. Verification of Carbon Sink Assessment. Can We Exclude Natural Sinks?

    International Nuclear Information System (INIS)

    Alexandrov, G.; Yamagata, Y


    Any human-induced terrestrial sink is susceptible to the effects of elevated atmospheric CO2 concentration, nitrogen deposition, climate variability and other natural or indirect human-induced factors. It has been suggested in climate negotiations that the effects of these factors should be excluded from estimates of carbon sequestration used to meet the emission reduction commitments under the Kyoto Protocol. This paper focuses on the methodologies for factoring out the effects of atmospheric and climate variability/change. We estimate the relative magnitude of the non-human induced effects by using two biosphere models and discuss possibilities for narrowing estimate uncertainty

  12. Investigation of internally finned LED heat sinks (United States)

    Li, Bin; Xiong, Lun; Lai, Chuan; Tang, Yumei


    A novel heat sink is proposed, which is composed of a perforated cylinder and internally arranged fins. Numerical studies are performed on the natural convection heat transfer from internally finned heat sinks; experimental studies are carried out to validate the numerical results. To compare the thermal performances of internally finned heat sinks and externally finned heat sinks, the effects of the overall diameter, overall height, and installation direction on maximum temperature, air flow and heat transfer coefficient are investigated. The results demonstrate that internally finned heat sinks show better thermal performance than externally finned heat sinks; the maximum temperature of internally finned heat sinks decreases by up to 20% compared with the externally finned heat sinks. The existence of a perforated cylinder and the installation direction of the heat sink affect the thermal performance significantly; it is shown that the heat transfer coefficient of the heat sink with the perforated cylinder is improved greater than that with the imperforated cylinder by up to 34%, while reducing the mass of the heat sink by up to 13%. Project supported by the Scientific Research Fund of Sichuan Provincial Education Department (No. 18ZB0516) and the Sichuan University of Arts and Science (No. 2016KZ009Y).

  13. Numerical study and optimizing on micro square pin-fin heat sink for electronic cooling

    International Nuclear Information System (INIS)

    Zhao, Jin; Huang, Shanbo; Gong, Liang; Huang, Zhaoqin


    Micro pin-fin heat sink, characterized by low thermal resistance, compact structure and uniform temperature distribution along the flow direction, is effective and valuable for thermal management of electronic devices. To enhance the cooling performance of the micro square pin-fin heat sink, a geometry optimizing method changing pin-fin porosity and pin-fin located angle is proposed in this paper. The flow and heat transfer characteristics were studied numerically and the geometry of the micro square pin-fin heat sink was optimized. To reveal the characteristics and advantages of the micro square pin-fin heat sink, the comparison between the square pin-fin and the column pin-fin was made. Numerical results indicate that both the pin-fin porosity and located angle are important for the cooling capacity and thermal performance of the micro square pin-fin heat sink; the optimal porosity and located angle for thermal performance are 0.75 and 30° respectively. Furthermore, micro heat sinks with the optimized square pin-fin present better thermal performance than micro column pin-fin heat sinks, which implies that there is great potential to employ micro square pin-fin heat sinks for thermal management on electronic devices with high energy density. - Highlights: • An optimization method on geometry is proposed for micro square pin-fin heat sink. • Pin-fin porosity and pin-fin located angle are important on thermal performance. • Heat sinks with optimized square pin-fin hold higher cooling capacity than column pin-fin.

  14. Faster than Nyquist signaling algorithms to silicon

    CERN Document Server

    Dasalukunte, Deepak; Rusek, Fredrik; Anderson, John B


    This book addresses the challenges and design trade-offs arising during the hardware design of Faster-than-Nyquist (FTN) signaling transceivers. The authors describe how to design for coexistence between the FTN system described and Orthogonal frequency-division multiplexing (OFDM) systems, enabling readers to design FTN specific processing blocks as add-ons to the conventional transceiver chain.   • Provides a comprehensive introduction to Faster-than-Nyquist (FTN) signaling transceivers, covering both theory and hardware implementation; • Enables readers to design systems that achieve bandwidth efficiency by making better use of the available spectrum resources; • Describes design techniques to achieve 2x improvement in bandwidth usage with similar performance as that of an OFDM system.  

  15. Pigeons home faster through polluted air


    Zhongqiu Li; Franck Courchamp; Daniel T. Blumstein


    Air pollution, especially haze pollution, is creating health issues for both humans and other animals. However, remarkably little is known about how animals behaviourally respond to air pollution. We used multiple linear regression to analyse 415 pigeon races in the North China Plain, an area with considerable air pollution, and found that while the proportion of pigeons successfully homed was not influenced by air pollution, pigeons homed faster when the air was especially polluted. Our resu...

  16. Faster than light, slower than time

    International Nuclear Information System (INIS)

    Rucker, R.


    The problem with faster-than-light travel is that, in the framework of Special Relativity, it is logically equivalent to time-travel. The problem with time-travel is that it leads to two types of paradoxes. The paradoxes, and the various means of skirting them, are all discussed here. Virtually all the examples are drawn from science-fiction novels, which are a large and neglected source of thought-experiments. (Auth.)

  17. Emission and Sink of Greenhouse Gases in Soils of Moscow (United States)

    Mozharova, N. V.; Kulachkova, S. A.; Lebed'-Sharlevich, Ya. I.


    The first inventory and zoning of the emission and sink of methane and carbon dioxide in the urban structure of greenhouse gases from soils and surface technogenic formations (STFs) (Technosols) on technogenic, recrementogenic, and natural sediments have been performed with consideration for the global warming potential under conditions of different formation rate of these gases, underflooding, and sealing. From gas geochemical criteria and anthropogenic pedogenesis features, the main sources of greenhouse gases, their intensity, and mass emission were revealed. The mass fractions of emissions from the sectors of waste and land use in the inventories of greenhouse gas emissions have been determined. New sources of gas emission have been revealed in the first sector, the emissions from which add tens of percent to the literature and state reports. In the second sector, emissions exceed the available data in 70 times. Estimation criteria based on the degree of manifestation and chemical composition of soil-geochemical anomalies and barrier capacities have been proposed. The sink of greenhouse gases from the atmosphere and the internal (latent) sink of methane in soils and STFs have been determined. Ecological functions of soils and STFs have been shown, and the share of latent methane sink has been calculated. The bacterial oxidation of methane in soils and STFs exceeds its emission to the atmosphere in almost hundred times.

  18. Compressing bitmap indexes for faster search operations

    International Nuclear Information System (INIS)

    Wu, Kesheng; Otoo, Ekow J.; Shoshani, Arie


    In this paper, we study the effects of compression on bitmap indexes. The main operations on the bitmaps during query processing are bitwise logical operations such as AND, OR, NOT, etc. Using the general purpose compression schemes, such as gzip, the logical operations on the compressed bitmaps are much slower than on the uncompressed bitmaps. Specialized compression schemes, like the byte-aligned bitmap code(BBC), are usually faster in performing logical operations than the general purpose schemes, but in many cases they are still orders of magnitude slower than the uncompressed scheme. To make the compressed bitmap indexes operate more efficiently, we designed a CPU-friendly scheme which we refer to as the word-aligned hybrid code (WAH). Tests on both synthetic and real application data show that the new scheme significantly outperforms well-known compression schemes at a modest increase in storage space. Compared to BBC, a scheme well-known for its operational efficiency, WAH performs logical operations about 12 times faster and uses only 60 percent more space. Compared to the uncompressed scheme, in most test cases WAH is faster while still using less space. We further verified with additional tests that the improvement in logical operation speed translates to similar improvement in query processing speed

  19. Compressing bitmap indexes for faster search operations

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kesheng; Otoo, Ekow J.; Shoshani, Arie


    In this paper, we study the effects of compression on bitmap indexes. The main operations on the bitmaps during query processing are bitwise logical operations such as AND, OR, NOT, etc. Using the general purpose compression schemes, such as gzip, the logical operations on the compressed bitmaps are much slower than on the uncompressed bitmaps. Specialized compression schemes, like the byte-aligned bitmap code(BBC), are usually faster in performing logical operations than the general purpose schemes, but in many cases they are still orders of magnitude slower than the uncompressed scheme. To make the compressed bitmap indexes operate more efficiently, we designed a CPU-friendly scheme which we refer to as the word-aligned hybrid code (WAH). Tests on both synthetic and real application data show that the new scheme significantly outperforms well-known compression schemes at a modest increase in storage space. Compared to BBC, a scheme well-known for its operational efficiency, WAH performs logical operations about 12 times faster and uses only 60 percent more space. Compared to the uncompressed scheme, in most test cases WAH is faster while still using less space. We further verified with additional tests that the improvement in logical operation speed translates to similar improvement in query processing speed.

  20. Sink-to-Sink Coordination Framework Using RPL: Routing Protocol for Low Power and Lossy Networks

    Directory of Open Access Journals (Sweden)

    Meer M. Khan


    Full Text Available RPL (Routing Protocol for low power and Lossy networks is recommended by Internet Engineering Task Force (IETF for IPv6-based LLNs (Low Power and Lossy Networks. RPL uses a proactive routing approach and each node always maintains an active path to the sink node. Sink-to-sink coordination defines syntax and semantics for the exchange of any network defined parameters among sink nodes like network size, traffic load, mobility of a sink, and so forth. The coordination allows sink to learn about the network condition of neighboring sinks. As a result, sinks can make coordinated decision to increase/decrease their network size for optimizing over all network performance in terms of load sharing, increasing network lifetime, and lowering end-to-end latency of communication. Currently, RPL does not provide any coordination framework that can define message exchange between different sink nodes for enhancing the network performance. In this paper, a sink-to-sink coordination framework is proposed which utilizes the periodic route maintenance messages issued by RPL to exchange network status observed at a sink with its neighboring sinks. The proposed framework distributes network load among sink nodes for achieving higher throughputs and longer network’s life time.

  1. Mechanical Determinants of Faster Change of Direction and Agility Performance in Female Basketball Athletes. (United States)

    Spiteri, Tania; Newton, Robert U; Binetti, Molly; Hart, Nicolas H; Sheppard, Jeremy M; Nimphius, Sophia


    Change of direction (COD) and agility require the integration of multiple components to produce a faster performance. However, the mechanisms contributing to a faster performance without the confounding factor of athlete expertise or gender is currently unknown. Therefore, the purpose of this study was to assess body composition, strength, and kinetic profile required for a faster COD and agility performance across multiple directional changes. Six faster and 6 slower (n = 12) elite female basketball athletes completed a maximal dynamic back squat; eccentric and concentric only back squat; isometric midthigh pull; whole-body scan to determine lean, fat, and total mass; 505 COD test; T-test; and a multidirectional agility test over in-ground force plates to obtain relevant kinetic measures. Group (faster and slower) by test (2 × 3) multivariate analyses of variance with follow-up analyses of variance were conducted to examine differences between faster and slower groups and each COD and agility test (p ≤ 0.05). Faster athletes during the 505 COD test produced significantly greater vertical force (p = 0.002) and eccentric and isometric strength capacity (p = 0.001). Faster agility and T-test athletes demonstrated significantly shorter contact times (p = 0.001), greater propulsive impulse (p = 0.02), isometric strength, and relative lean mass compared with slower athletes. Differences between faster athletes across each test seem to be attributed to the mechanical demands of the directional change, increasing force and impulse application as the degree of directional change increased. These findings indicate that different mechanical properties are required to produce a faster COD and agility performances, and the importance of a greater strength capacity to enable greater mechanical adjustment through force production and body control, during different directional changes.

  2. Moving multiple sinks through wireless sensor networks for lifetime maximization.

    Energy Technology Data Exchange (ETDEWEB)

    Petrioli, Chiara (Universita di Roma); Carosi, Alessio (Universita di Roma); Basagni, Stefano (Northeastern University); Phillips, Cynthia Ann


    Unattended sensor networks typically watch for some phenomena such as volcanic events, forest fires, pollution, or movements in animal populations. Sensors report to a collection point periodically or when they observe reportable events. When sensors are too far from the collection point to communicate directly, other sensors relay messages for them. If the collection point location is static, sensor nodes that are closer to the collection point relay far more messages than those on the periphery. Assuming all sensor nodes have roughly the same capabilities, those with high relay burden experience battery failure much faster than the rest of the network. However, since their death disconnects the live nodes from the collection point, the whole network is then dead. We consider the problem of moving a set of collectors (sinks) through a wireless sensor network to balance the energy used for relaying messages, maximizing the lifetime of the network. We show how to compute an upper bound on the lifetime for any instance using linear and integer programming. We present a centralized heuristic that produces sink movement schedules that produce network lifetimes within 1.4% of the upper bound for realistic settings. We also present a distributed heuristic that produces lifetimes at most 25:3% below the upper bound. More specifically, we formulate a linear program (LP) that is a relaxation of the scheduling problem. The variables are naturally continuous, but the LP relaxes some constraints. The LP has an exponential number of constraints, but we can satisfy them all by enforcing only a polynomial number using a separation algorithm. This separation algorithm is a p-median facility location problem, which we can solve efficiently in practice for huge instances using integer programming technology. This LP selects a set of good sensor configurations. Given the solution to the LP, we can find a feasible schedule by selecting a subset of these configurations, ordering them

  3. Variable food absorption by Antarctic krill: Relationships between diet, egestion rate and the composition and sinking rates of their fecal pellets (United States)

    Atkinson, A.; Schmidt, K.; Fielding, S.; Kawaguchi, S.; Geissler, P. A.


    The kinetics of food processing by zooplankton affects both their energy budgets and the biogeochemical fate of their fecal pellets. We sampled 40 schools of krill across the Scotia Sea during spring, summer and autumn and found that in all 3 seasons, every aspect of their absorption and defecation varied greatly. The C content of fecal pellets varied from 0.85% to 29% of their dry mass (median 9.8%) and C egestion rates varied 75-fold. C:N mass ratios of pellets ranged from 4.9 to 13.2 (median 7.8), higher than values of 3.9 in the krill and 5.4 in their food, pointing to enhanced uptake of N. Pellet sinking rates equated to 27-1218 m d -1 (median 304 m d -1), being governed mainly by pellet diameter (80-600 μm, mean 183 μm) and density (1.038-1.391 g cm -3, mean 1.121 g cm -3). Pellets showed little loss of C or N in filtered seawater over the first 2 days and were physically robust. When feeding rates were low, slow gut passage time and high absorption efficiency resulted in low egestion rates of pellets that were low in C and N content. These pellets were compact, dense and fast-sinking. Conversely, in good feeding conditions much food tended to pass quickly through the gut and was not efficiently absorbed, producing C and N-rich, slow-sinking pellets. Such "superfluous feeding" probably maximises the absolute rates of nutrient absorption. Food composition was also important: diatom-rich diets depressed the C content of the pellets but increased their sinking rates, likely due to silica ballasting. So depending on how krill process food, their pellets could represent both vehicles for rapid export and slow sinking, C and N-rich food sources for pelagic scavengers. C egestion rates by krill averaged 3.4% of summer primary production (and ingestion rates would be 2-10-fold higher than this) so whatever the fate of the pellets, krill are an important re-packager within the food web. While salp pellets tend to sink faster than those of krill, it is the latter

  4. Faster multiple emulsification with drop splitting. (United States)

    Abate, Adam R; Weitz, David A


    Microfluidic devices can form emulsions in which the drops have an intricate, controlled structure; however, a challenge is that the droplets are produced slowly, typically only a few millilitres per hour. Here, we present a simple technique to increase the production rate. Using a large drop maker, we produce large drops at a fast volumetric rate; by splitting these drops several times in a splitting array, we create drops of the desired small size. The advantage of this over forming the small drops directly using a small drop maker is that the drops can be formed at much faster rates. This can be applied to the production of single and multiple emulsions.

  5. Better Faster Noise with the GPU

    DEFF Research Database (Denmark)

    Wyvill, Geoff; Frisvad, Jeppe Revall

    Filtered noise [Perlin 1985] has, for twenty years, been a fundamental tool for creating functional texture and it has many other applications; for example, animating water waves or the motion of grass waving in the wind. Perlin noise suffers from a number of defects and there have been many atte...... attempts to create better or faster noise but Perlin’s ‘Gradient Noise’ has consistently proved to be the best compromise between speed and quality. Our objective was to create a better noise cheaply by use of the GPU....

  6. Forced air heat sink apparatus (United States)

    Rippel, Wally E. (Inventor)


    A high efficiency forced air heat sink assembly employs a split feed transverse flow configuration to minimize the length of the air flow path through at least two separated fin structures. Different embodiments use different fin structure material configurations including honeycomb, corrugated and serpentine. Each such embodiment uses a thermally conductive plate having opposed exterior surfaces; one for receiving a component to be cooled and one for receiving the fin structures. The serpentine structured fin embodiment employs a plurality of fin supports extending from the plate and forming a plurality of channels for receiving the fin structures. A high thermal conductivity bondant, such as metal-filled epoxy, may be used to bond the fin structures to either the plate or the fin supports. Dip brazing and soldering may also be employed depending upon the materials selected.

  7. Fracture as a material sink (United States)

    Volokh, K. Y.


    Cracks are created by massive breakage of molecular or atomic bonds. The latter, in its turn, leads to the highly localized loss of material, which is the reason why even closed cracks are visible by a naked eye. Thus, fracture can be interpreted as the local material sink. Mass conservation is violated locally in the area of material failure. We consider a theoretical formulation of the coupled mass and momenta balance equations for a description of fracture. Our focus is on brittle fracture and we propose a finite strain hyperelastic thermodynamic framework for the coupled mass-flow-elastic boundary value problem. The attractiveness of the proposed framework as compared to the traditional continuum damage theories is that no internal parameters (like damage variables, phase fields, etc.) are used while the regularization of the failure localization is provided by the physically sound law of mass balance.

  8. Development of the FASTER Wheeled Bevameter (United States)

    Richter, L.; Eder, V.; Hoheneder, W.; Imhof, B.; Lewinger, W.; Ransom, S.; Saaj, C.; Weclewski, P.; Waclavicek, R.,


    This paper describes the development of a Wheeled Bevameter (WB) within the FASTER project (Forward Acquisition of Soil and Terrain Data for Exploration Rovers), funded by the European Union's FP7 programme. In FASTER, novel and innovative concepts for in situ forward sensing of soil properties and terrain conditions in the planned path of a planetary rover are developed. Terrain strength measurements for assessment of the mobility of crosscountry vehicles have decades of heritage on Earth, but typically trafficability of terrains is only gauged by human operators ahead of vehicle operations rather than in-line by probes deployed from the vehicle itself, as is intended for FASTER. For FASTER, a Wheeled Bevameter (WB) has been selected as the terrain sensing instrument for the vehicle. Wheeled Bevameters are suitable for terrain measurements while driving but traditionally have mostly been employed on terrestrial vehicles to evaluate particular wheel designs. The WB as conceived in FASTER uses a dedicated, passive-rolling test wheel (‚test wheel') placed on the terrain as the loading device to enable to determine bearing strength, compressive strength and shear strength of the terrain immediately ahead of the vehicle, as well as rover-terrain interaction parameters used in semi-empirical vehicle-terrain traction models. The WB includes a placement mechanism for the test wheel. The test wheel would remain lowered onto the ground during nominal rover motion, including when climbing and descending slopes. During normal operations, the placement mechanism assumes the function of a passive suspension of the wheel, allowing it to follow the terrain contour. Quantities measured with the WB are: test wheel sinkage (through a laser sensor), test wheel vertical load, test wheel horizontal reaction force, and test wheel rotation rate. Measurements are performed while the rover is in motion. Measured test wheel rotation rate (with appropriate corrections for slight skid) can

  9. Economic optimization of heat sink design

    International Nuclear Information System (INIS)

    Ritzer, T.M.; Lau, P.G.


    This paper describes the analysis and derivation of an optimum heat sink design for maximizing the thermoelectric cooling performance of a laboratory liquid chiller. The methods employed consisted of certain key changes in the design of the heat sink in order to improve its thermal performance. Parametric studies were performed in order to determine the optimized cooling system design per dollar

  10. Thermoelectric heat sink modeling and optimization

    International Nuclear Information System (INIS)

    Buist, R.J.; Nagy, M.J.


    Proper design and optimization of a thermoelectric heat sinks has been neglected somewhat in the design of the thermoelectric cooling systems. TE Technology, Inc. has developed a model over a period of 30 hears. The use and application of this model through optimizing heat sink performance is presented

  11. Forest carbon sinks in the northern hemisphere

    NARCIS (Netherlands)

    Goodale, C.L.; Apps, M.J.; Birdsey, R.A.; Field, C.B.; Heath, L.S.; Houghton, R.A.; Jenkins, J.C.; Kohlmaier, G.H.; Kurz, W.; Liu, S.R.; Nabuurs, G.J.; Nilsson, S.; Shvidenko, A.Z.


    There is general agreement that terrestrial systems in the Northern Hemisphere provide a significant sink for atmospheric CO2; however, estimates of the magnitude and distribution of this sink vary greatly. National forest inventories provide strong, measuretment-based constraints on the magnitude

  12. Microbial communities evolve faster in extreme environments. (United States)

    Li, Sheng-Jin; Hua, Zheng-Shuang; Huang, Li-Nan; Li, Jie; Shi, Su-Hua; Chen, Lin-Xing; Kuang, Jia-Liang; Liu, Jun; Hu, Min; Shu, Wen-Sheng


    Evolutionary analysis of microbes at the community level represents a new research avenue linking ecological patterns to evolutionary processes, but remains insufficiently studied. Here we report a relative evolutionary rates (rERs) analysis of microbial communities from six diverse natural environments based on 40 metagenomic samples. We show that the rERs of microbial communities are mainly shaped by environmental conditions, and the microbes inhabiting extreme habitats (acid mine drainage, saline lake and hot spring) evolve faster than those populating benign environments (surface ocean, fresh water and soil). These findings were supported by the observation of more relaxed purifying selection and potentially frequent horizontal gene transfers in communities from extreme habitats. The mechanism of high rERs was proposed as high mutation rates imposed by stressful conditions during the evolutionary processes. This study brings us one stage closer to an understanding of the evolutionary mechanisms underlying the adaptation of microbes to extreme environments.

  13. Pigeons home faster through polluted air (United States)

    Li, Zhongqiu; Courchamp, Franck; Blumstein, Daniel T.


    Air pollution, especially haze pollution, is creating health issues for both humans and other animals. However, remarkably little is known about how animals behaviourally respond to air pollution. We used multiple linear regression to analyse 415 pigeon races in the North China Plain, an area with considerable air pollution, and found that while the proportion of pigeons successfully homed was not influenced by air pollution, pigeons homed faster when the air was especially polluted. Our results may be explained by an enhanced homing motivation and possibly an enriched olfactory environment that facilitates homing. Our study provides a unique example of animals’ response to haze pollution; future studies are needed to identify proposed mechanisms underlying this effect.


    Possible environmental sinks (wastewater effluents, biosolids, sediments) of macrolide antibiotics (i.e., azithromycin, roxithromycin and clarithromycin)are investigated using state-of-the-art analytical chemistry techniques. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews

  15. Mechanisms and rates of bacterial colonization of sinking aggregates

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Grossart, H.P.; Ploug, H.


    Quantifying the rate at which bacteria colonize aggregates is a key to understanding microbial turnover of aggregates. We used encounter models based on random walk and advection-diffusion considerations to predict colonization rates from the bacteria's motility patterns (swimming speed, tumbling...... (0 to 2 s(-1)). The rates at which these bacteria colonized artificial aggregates (stationary and sinking) largely agreed with model predictions. We report several findings. (i) Motile bacteria rapidly colonize aggregates, whereas nonmotile bacteria do not. 00 Flow enhances colonization rates. (iii......) Tumbling strains colonize aggregates enriched with organic substrates faster than unenriched aggregates, while a nontumbling strain did not. (iv) Once on the aggregates, the bacteria may detach and typical residence time is about 3 h. Thus, there is a rapid exchange between attached and free bacteria. (v...

  16. Ocean carbon sinks and international climate policy

    International Nuclear Information System (INIS)

    Rehdanz, Katrin; Tol, Richard S.J.; Wetzel, Patrick


    Terrestrial vegetation sinks have entered the Kyoto Protocol as offsets for anthropogenic greenhouse gas emissions, but ocean sinks have escaped attention. Ocean sinks are as unexplored and uncertain as were the terrestrial sinks at the time of negotiation of the Kyoto Protocol. It is not unlikely that certain countries will advocate the inclusion of ocean carbon sinks to reduce their emission reduction obligations in post-2012 negotiations. We use a simple model of the international market for carbon dioxide emissions to evaluate who would gain or loose from allowing for ocean carbon sinks. Our analysis is restricted to information on anthropogenic carbon sequestration within the exclusive economic zone of a country. We use information on the actual carbon flux and derive the human-induced uptake for the period from 1990 onwards. Like the carbon sequestration of business as usual forest management activities, natural ocean carbon sequestration applies at zero costs. The total amount of anthropogenic ocean carbon sequestration is large, also in the exclusive economic zones. As a consequence, it substantially alters the costs of emission reduction for most countries. Countries such as Australia, Denmark, France, Iceland, New Zealand, Norway and Portugal would gain substantially, and a large number of countries would benefit too. Current net exporters of carbon permits, particularly Russia, would gain less and oppose the inclusion of ocean carbon sinks

  17. Fast Physics Testbed for the FASTER Project

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W.; Liu, Y.; Hogan, R.; Neggers, R.; Jensen, M.; Fridlind, A.; Lin, Y.; Wolf, A.


    This poster describes the Fast Physics Testbed for the new FAst-physics System Testbed and Research (FASTER) project. The overall objective is to provide a convenient and comprehensive platform for fast turn-around model evaluation against ARM observations and to facilitate development of parameterizations for cloud-related fast processes represented in global climate models. The testbed features three major components: a single column model (SCM) testbed, an NWP-Testbed, and high-resolution modeling (HRM). The web-based SCM-Testbed features multiple SCMs from major climate modeling centers and aims to maximize the potential of SCM approach to enhance and accelerate the evaluation and improvement of fast physics parameterizations through continuous evaluation of existing and evolving models against historical as well as new/improved ARM and other complementary measurements. The NWP-Testbed aims to capitalize on the large pool of operational numerical weather prediction products. Continuous evaluations of NWP forecasts against observations at ARM sites are carried out to systematically identify the biases and skills of physical parameterizations under all weather conditions. The highresolution modeling (HRM) activities aim to simulate the fast processes at high resolution to aid in the understanding of the fast processes and their parameterizations. A four-tier HRM framework is established to augment the SCM- and NWP-Testbeds towards eventual improvement of the parameterizations.

  18. The Sinking Sequence of MV Estonia


    Kehren, Felix-Ingo


    This thesis reconstructs the sinking of the RoPax Ferry MV Estonia on September 28th 1994, with a strong focus on describing the chain of events that caused the eventual sinking, and how the ship sank. Once the sinking is understood, this thesis explores possible safety improvements that should be implemented in the design of new vessels of this type. The investigation is based on a combination of testimonies of survivors as well as numerical calculations based on the framework of the testimo...

  19. Biological control of the terrestrial carbon sink

    Directory of Open Access Journals (Sweden)

    E.-D. Schulze


    Full Text Available This lecture reviews the past (since 1964 when the International Biological Program began and the future of our understanding of terrestrial carbon fluxes with focus on photosynthesis, respiration, primary-, ecosystem-, and biome-productivity. Photosynthetic capacity is related to the nitrogen concentration of leaves, but the capacity is only rarely reached under field conditions. Average rates of photosynthesis and stomatal conductance are closely correlated and operate near 50% of their maximal rate, with light being the limiting factor in humid regions and air humidity and soil water the limiting factor in arid climates. Leaf area is the main factor to extrapolate from leaves to canopies, with maximum surface conductance being dependent on leaf level stomatal conductance. Additionally, gas exchange depends also on rooting depth which determines the water and nutrient availability and on mycorrhizae which regulate the nutrient status. An important anthropogenic disturbance is the nitrogen uptake from air pollutants, which is not balanced by cation uptake from roots and this may lead to damage and breakdown of the plant cover. Photosynthesis is the main carbon input into ecosystems, but it alone does not represent the ecosystem carbon balance, which is determined by respiration of various kinds. Plant respiration and photosynthesis determine growth (net primary production and microbial respiration balances the net ecosystem flux. In a spruce forest, 30% of the assimilatory carbon gain is used for respiration of needles, 20% is used for respiration in stems. Soil respiration is about 50% the carbon gain, half of which is root respiration, half is microbial respiration. In addition, disturbances lead to carbon losses, where fire, harvest and grazing bypass the chain of respiration. In total, the carbon balance at the biome level is only about 1% of the photosynthetic carbon input, or may indeed become negative. The recent observed increase in

  20. Mesoscale inversion of carbon sources and sinks

    International Nuclear Information System (INIS)

    Lauvaux, T.


    Inverse methods at large scales are used to infer the spatial variability of carbon sources and sinks over the continents but their uncertainties remain large. Atmospheric concentrations integrate the surface flux variability but atmospheric transport models at low resolution are not able to simulate properly the local atmospheric dynamics at the measurement sites. However, the inverse estimates are more representative of the large spatial heterogeneity of the ecosystems compared to direct flux measurements. Top-down and bottom-up methods that aim at quantifying the carbon exchanges between the surface and the atmosphere correspond to different scales and are not easily comparable. During this phD, a mesoscale inverse system was developed to correct carbon fluxes at 8 km resolution. The high resolution transport model MesoNH was used to simulate accurately the variability of the atmospheric concentrations, which allowed us to reduce the uncertainty of the retrieved fluxes. All the measurements used here were observed during the intensive regional campaign CERES of May and June 2005, during which several instrumented towers measured CO 2 concentrations and fluxes in the South West of France. Airborne measurements allowed us to observe concentrations at high altitude but also CO 2 surface fluxes over large parts of the domain. First, the capacity of the inverse system to correct the CO 2 fluxes was estimated using pseudo-data experiments. The largest fraction of the concentration variability was attributed to regional surface fluxes over an area of about 300 km around the site locations depending on the meteorological conditions. Second, an ensemble of simulations allowed us to define the spatial and temporal structures of the transport errors. Finally, the inverse fluxes at 8 km resolution were compared to direct flux measurements. The inverse system has been validated in space and time and showed an improvement of the first guess fluxes from a vegetation model

  1. A Possible Sink for Methane on Mars

    NARCIS (Netherlands)

    Nørnberg, P.; Jensen, S. J. K.; Skibsted, J.; Jakobsen, H. J.; ten Kate, I. L.; Gunnlaugsson, H. P.; Merrison, J. P.; Finster, K.; Bak, E.; Iversen, J. J.; Kondrup, J. C.


    Mechanical simulated wind activation of mineral surfaces act as a trap for Methane through formation of covalent Si-C bonds stable up to temperatures above 250 C. This mechanism is proposed as a Methane sink on Mars.

  2. Reduced growth due to belowground sink limitation is not fully explained by reduced photosynthesis. (United States)

    Campany, Courtney E; Medlyn, Belinda E; Duursma, Remko A


    Sink limitation is known to reduce plant growth, but it is not known how plant carbon (C) balance is affected, limiting our ability to predict growth under sink-limited conditions. We manipulated soil volume to impose sink limitation of growth in Eucalyptus tereticornis Sm. seedlings. Seedlings were grown in the field in containers of different sizes and planted flush to the soil alongside freely rooted (Free) seedlings. Container volume negatively affected aboveground growth throughout the experiment, and light saturated rates of leaf photosynthesis were consistently lower in seedlings in containers (-26%) compared with Free seedlings. Significant reductions in photosynthetic capacity in containerized seedlings were related to both reduced leaf nitrogen content and starch accumulation, indicating direct effects of sink limitation on photosynthetic downregulation. After 120 days, harvested biomass of Free seedlings was on average 84% higher than seedlings in containers, but biomass distribution in leaves, stems and roots was not different. However, the reduction in net leaf photosynthesis over the growth period was insufficient to explain the reduction in growth, so that we also observed an apparent reduction in whole-plant C-use efficiency (CUE) between Free seedlings and seedlings in containers. Our results show that sink limitation affects plant growth through feedbacks to both photosynthesis and CUE. Mass balance approaches to predicting plant growth under sink-limited conditions need to incorporate both of these feedbacks. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email:

  3. Sink Potential of Canadian Agricultural Soils

    International Nuclear Information System (INIS)

    Boehm, M.; Junkins, B.; Desjardins, R.; Lindwall, W.; Kulshreshtha, S.


    Net greenhouse gas (GHG) emissions from Canadian crop and livestock production were estimated for 1990, 1996 and 2001 and projected to 2008. Net emissions were also estimated for three scenarios (low (L), medium (M) and high (H)) of adoption of sink enhancing practices above the projected 2008 level. Carbon sequestration estimates were based on four sink-enhancing activities: conversion from conventional to zero tillage (ZT), reduced frequency of summerfallow (SF), the conversion of cropland to permanent cover crops (PC), and improved grazing land management (GM). GHG emissions were estimated with the Canadian Economic and Emissions Model for Agriculture (CEEMA). CEEMA estimates levels of production activities within the Canadian agriculture sector and calculates the emissions and removals associated with those levels of activities. The estimates indicate a decline in net emissions from 54 Tg CO2-Eq yr-1 in 1990 to 52 Tg CO2-Eq yr-1 in 2008. Adoption of the sink-enhancing practices above the level projected for 2008 resulted in further declines in emissions to 48 Tg CO2-Eq yr-1 (L), 42 Tg CO2-Eq yr-1 (M) or 36 Tg CO2-Eq yr-1 (H). Among the sink-enhancing practices, the conversion from conventional tillage to ZT provided the largest C sequestration potential and net reduction in GHG emissions among the scenarios. Although rates of C sequestration were generally higher for conversion of cropland to PC and adoption of improved GM, those scenarios involved smaller areas of land and therefore less C sequestration. Also, increased areas of PC were associated with an increase in livestock numbers and CH4 and N2O emissions from enteric fermentation and manure, which partially offset the carbon sink. The CEEMA estimates indicate that soil C sinks are a viable option for achieving the UNFCCC objective of protecting and enhancing GHG sinks and reservoirs as a means of reducing GHG emissions (UNFCCC, 1992)

  4. Carbon sink activity of managed grasslands (United States)

    Klumpp, Katja; Chabbi, Abad; Gastal, Francois; Senapati, Nimai; Charrier, Xavier; Darsonville, Olivier; Creme, Alexandra


    In agriculture, a large proportion of GHG emission saving potential may be achieved by means of soil C sequestration. Recent demonstrations of carbon sink activities however, often questioned the existence of C storing grasslands, as uncertainty surrounding estimates are often larger than the sink itself. Besides climate, key components of the carbon sink activity in grasslands are type and intensity of management practices. Here, we analysed long term data on C flux and soil organic carbon stocks for two long term (>13yrs) national observation sites in France (SOERE-ACBB). These sites comprise a number of grassland fields and managements options (i.e. permanent, sowing, grazing, mowing, and fertilization) offering an opportunity to study carbon offsets (i.e. compensation of CH4 and N2O emissions), climatic-management interactions and trade-offs concerning ecosystem services (e.g. production). Furthermore, for some grassland fields, the carbon sink activity was compared using two methods; repeated soil inventory and estimation of the ecosystem C budget by continuous measurement of CO2 exchange (i.e. eddy covariance) in combination with quantification of other C imports and exports, necessary to estimate net C storage. In general grasslands, were a potential sink of C (i.e. net ecosystem exchange, NEE), where grazed sites had lower NEE compared the cut site. However, when it comes to net C storage (NCS), mowing reduced markedly potential sink leading to very low NCS compared to grazed sites. Including non-CO2 fluxes (CH4 and N2O emission) in the budget, revealed that GHG emissions were offset by C sink activity.

  5. Development of Thermal Design Program for an Electronic Telecommunication System Using Heat Sink

    International Nuclear Information System (INIS)

    Lee, Jung Hwan; Kim, Jong Man; Chun, Ji Hwan; Bae, Chul Ho; Suh, Myung Won


    The purpose of this study is to investigate the cooling performance of heat sinks for an electronic telecommunication system by adequate natural convection. Heat generation rates of electronic components and the temperature distributions of heat sinks and surrounding air are analyzed experimentally and numerically. In order to perform the heat transfer analysis for the thermal design of telecommunication system, a program is developed. The program used the graphic user interface environment to determine the arrangement of heat sources, interior fan capacity, and heat sink configuration. The simulation results showed that the heat sinks were able to achieve a cooling capacity of up to 230W at the maximum temperature difference of 19 .deg. C. To verify the results from the numerical simulation, an experiment was conducted under the same condition as the numerical simulation, and their results were compared. The design program gave good prediction of the effects of various parameters involved in the design of a heat sinks for an electronic telecommunication system

  6. Landfills as sinks for (hazardous) substances. (United States)

    Scharff, Heijo


    The primary goal of waste regulations is to protect human health and the environment. This requires the removal from the material cycle of those materials that cannot be processed without harm. Policies to promote recycling hold a risk that pollutants are dispersed. Materials have an environmental impact during their entire life cycle from extraction through production, consumption and recycling to disposal. Essentially there are only two routes for pollutants that cannot be rendered harmless: storage in sinks or dispersion into the environment. Many sinks do not contain substances absolutely, but result in slow dispersion. Dispersion leads to exposure and impact to human health and the environment. It is therefore important to assess the impact of the release to the environment. Based on various sources this paper discusses important material flows and their potential impact. This is compared with the intentions and achievements of European environmental and resource policy. The polluter pays principle is being implemented in Europe, but lags behind implementation of waste management regulations. As long as producers are allowed to add hazardous substances to their products and don't take their products back, it is in society's best interest to carefully consider whether recycling or storage in a sink is the better solution. This requires further development of life-cycle assessment tools and harmonization of regulations. In many cases the sink is unavoidable. Landfills as sinks will be needed in the future. Fail-safe design and construction as well as sustainable management of landfills must be further developed.

  7. Pharmacological Properties of Faster-Acting Insulin Aspart. (United States)

    Biester, Torben; Kordonouri, Olga; Danne, Thomas


    Faster aspart is a new formulation of insulin aspart (IAsp) produced by adding the excipients niacinamide and L-arginine. As this new, "ultra-rapid insulin" is available in the EU-market and Canada, the pharmacokinetic and pharmacodynamics data is summarized. Faster aspart shows an earlier onset of appearance of insulin in the bloodstream after subcutaneous administration and an earlier onset of glucose-lowering action and a higher glycemic effect within the first 30 min. Faster aspart administered by pump is indeed faster than conventional aspart with a faster on (- 11 min), faster off (- 24 min), and more than 100% greater insulin action within the first 30 min. Tolerability of faster aspart is similar to that of Iasp; the same holds true for compatibility in pump use. Faster aspart shows a faster occurrence of insulin in the blood compared with IAsp in subcutaneous injection. Improvements over current analogs may be more pronounced in pumps than with injections. Data from phase IIIa studies confirm the reduction of postprandial glucose excursions that can be achieved with faster aspart.

  8. Topology Optimization of Thermal Heat Sinks

    DEFF Research Database (Denmark)

    Klaas Haertel, Jan Hendrik; Engelbrecht, Kurt; Lazarov, Boyan Stefanov


    In this paper, topology optimization is applied to optimize the cooling performance of thermal heat sinks. The coupled two-dimensional thermofluid model of a heat sink cooled with forced convection and a density-based topology optimization including density filtering and projection are implemented...... in COMSOL Multiphysics. The optimization objective is to minimize the heat sink’s temperature for a prescribed pressure drop and fixed heat generation. To conduct the optimization, COMSOL’s Optimization Module with GCMMA as the optimization method is used. The implementation of this topology optimization...

  9. Exploiting leaf starch synthesis as a transient sink to elevate photosynthesis, plant productivity and yields. (United States)

    Gibson, Kelly; Park, Jong-Sug; Nagai, Yasuko; Hwang, Seon-Kap; Cho, Young-Chan; Roh, Kyung-Hee; Lee, Si-Myung; Kim, Dong-Hern; Choi, Sang-Bong; Ito, Hiroyuki; Edwards, Gerald E; Okita, Thomas W


    Improvements in plant productivity (biomass) and yield have centered on increasing the efficiency of leaf CO(2) fixation and utilization of products by non-photosynthetic sink organs. We had previously demonstrated a correlation between photosynthetic capacity, plant growth, and the extent of leaf starch synthesis utilizing starch-deficient mutants. This finding suggested that leaf starch is used as a transient photosynthetic sink to recycle inorganic phosphate and, in turn, maximize photosynthesis. To test this hypothesis, Arabidopsis thaliana and rice (Oryza sativa L.) lines were generated with enhanced capacity to make leaf starch with minimal impact on carbon partitioning to sucrose. The Arabidopsis engineered plants exhibited enhanced photosynthetic capacity; this translated into increased growth and biomass. These enhanced phenotypes were displayed by similarly engineered rice lines. Manipulation of leaf starch is a viable alternative strategy to increase photosynthesis and, in turn, the growth and yields of crop and bioenergy plants. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Railway capacity


    Lavrič, Tadeja


    In the first part of the thesis, the concepts of railway capacity and capacity consumption are defined. Experts have in the past defined railway capacity in many different ways. This thesis outlines some definitions of railway capacity and capacity consumption, including the definition of railway capacity in accordance with the UIC code 406 (2004), given by the International Union of Railways in order to standardize the definition of railway capacity. Capacity and capacity consumption are dir...

  11. Regulation Effects of Water and Nitrogen on the Source-Sink Relationship in Potato during the Tuber Bulking Stage (United States)

    Li, Wenting; Xiong, Binglin; Wang, Shiwen; Deng, Xiping; Yin, Lina; Li, Hongbing


    The source-sink relationship determines crop yield, and it is largely regulated by water and nutrients in agricultural production. This has been widely investigated in cereals, but fewer studies have been conducted in root and tuber crops such as potato (Solanum tuberosum L.). The objective of this study was to investigate the source-sink relationship in potato and the regulation of water and nitrogen on the source-sink relationship during the tuber bulking stage. A pot experiment using virus-free plantlets of the Atlantic potato cultivar was conducted, using three water levels (50%, 70% and 90% of field capacity) and three nitrogen levels (0, 0.2, 0.4 g N∙kg−1 soil). The results showed that, under all water and nitrogen levels, plant source capacity were small at the end of the experiment, since photosynthetic activity in leaves were low and non-structural reserves in underground stems were completely remobilized. While at this time, there were very big differences in maximum and minimum tuber number and tuber weight, indicating that the sink tuber still had a large potential capacity to take in assimilates. These results suggest that the source-supplied assimilates were not sufficient enough to meet the demands of sink growth. Thus, we concluded that, unlike cereals, potato yield is more likely to be source-limited than sink-limited during the tuber bulking stage. Water and nitrogen are two key factors in potato production management. Our results showed that water level, nitrogen level and the interaction between water and nitrogen influence potato yield mainly through affecting source capacity via the net photosynthetic rate, total leaf area and leaf life span. Well-watered, sufficient nitrogen and well-watered combined with sufficient nitrogen increased yield mainly by enhancing the source capacity. Therefore, this suggests that increasing source capacity is more crucial to improve potato yield. PMID:26752657

  12. Regulation Effects of Water and Nitrogen on the Source-Sink Relationship in Potato during the Tuber Bulking Stage.

    Directory of Open Access Journals (Sweden)

    Wenting Li

    Full Text Available The source-sink relationship determines crop yield, and it is largely regulated by water and nutrients in agricultural production. This has been widely investigated in cereals, but fewer studies have been conducted in root and tuber crops such as potato (Solanum tuberosum L.. The objective of this study was to investigate the source-sink relationship in potato and the regulation of water and nitrogen on the source-sink relationship during the tuber bulking stage. A pot experiment using virus-free plantlets of the Atlantic potato cultivar was conducted, using three water levels (50%, 70% and 90% of field capacity and three nitrogen levels (0, 0.2, 0.4 g N∙kg-1 soil. The results showed that, under all water and nitrogen levels, plant source capacity were small at the end of the experiment, since photosynthetic activity in leaves were low and non-structural reserves in underground stems were completely remobilized. While at this time, there were very big differences in maximum and minimum tuber number and tuber weight, indicating that the sink tuber still had a large potential capacity to take in assimilates. These results suggest that the source-supplied assimilates were not sufficient enough to meet the demands of sink growth. Thus, we concluded that, unlike cereals, potato yield is more likely to be source-limited than sink-limited during the tuber bulking stage. Water and nitrogen are two key factors in potato production management. Our results showed that water level, nitrogen level and the interaction between water and nitrogen influence potato yield mainly through affecting source capacity via the net photosynthetic rate, total leaf area and leaf life span. Well-watered, sufficient nitrogen and well-watered combined with sufficient nitrogen increased yield mainly by enhancing the source capacity. Therefore, this suggests that increasing source capacity is more crucial to improve potato yield.

  13. Regulation Effects of Water and Nitrogen on the Source-Sink Relationship in Potato during the Tuber Bulking Stage. (United States)

    Li, Wenting; Xiong, Binglin; Wang, Shiwen; Deng, Xiping; Yin, Lina; Li, Hongbing


    The source-sink relationship determines crop yield, and it is largely regulated by water and nutrients in agricultural production. This has been widely investigated in cereals, but fewer studies have been conducted in root and tuber crops such as potato (Solanum tuberosum L.). The objective of this study was to investigate the source-sink relationship in potato and the regulation of water and nitrogen on the source-sink relationship during the tuber bulking stage. A pot experiment using virus-free plantlets of the Atlantic potato cultivar was conducted, using three water levels (50%, 70% and 90% of field capacity) and three nitrogen levels (0, 0.2, 0.4 g N∙kg-1 soil). The results showed that, under all water and nitrogen levels, plant source capacity were small at the end of the experiment, since photosynthetic activity in leaves were low and non-structural reserves in underground stems were completely remobilized. While at this time, there were very big differences in maximum and minimum tuber number and tuber weight, indicating that the sink tuber still had a large potential capacity to take in assimilates. These results suggest that the source-supplied assimilates were not sufficient enough to meet the demands of sink growth. Thus, we concluded that, unlike cereals, potato yield is more likely to be source-limited than sink-limited during the tuber bulking stage. Water and nitrogen are two key factors in potato production management. Our results showed that water level, nitrogen level and the interaction between water and nitrogen influence potato yield mainly through affecting source capacity via the net photosynthetic rate, total leaf area and leaf life span. Well-watered, sufficient nitrogen and well-watered combined with sufficient nitrogen increased yield mainly by enhancing the source capacity. Therefore, this suggests that increasing source capacity is more crucial to improve potato yield.

  14. 77 FR 64545 - Drawn Stainless Steel Sinks From China (United States)


    ... merchandise as ``drawn stainless steel sinks with single or multiple drawn bowls, with or without drain boards... finishing the vertical corners to form the bowls. Stainless steel sinks with fabricated bowls may sometimes...

  15. Limited Capacity for Faster Digestion in Larval Coral Reef Fish at an Elevated Temperature.

    Directory of Open Access Journals (Sweden)

    Ian M McLeod

    Full Text Available The prevalence of extreme, short-term temperature spikes in coastal regions during summer months is predicted to increase with ongoing climate change. In tropical systems, these changes are predicted to increase the metabolic demand of coral reef fish larvae while also altering the plankton communities upon which the larvae feed during their pelagic phase. The consequences of these predictions remain speculative in the absence of empirical data on the interactive effects of warm temperatures on the metabolism, postprandial processes and growth responses of coral reef fish larvae. Here, we tested the effect of increased temperature on the metabolism, postprandial performance and fine-scale growth patterns of a coral reef fish (Amphiprion percula in the latter half of its ~11-d larval phase. First, we measured the length and weight of fed versus fasted larvae (N = 340; mean body mass 4.1±0.05 mg across fine temporal scales at a typical current summer temperature (28.5°C and a temperature that is likely be encountered during warm summer periods later this century (31.5°C. Second, we measured routine metabolic rate (Mo2 routine and the energetics of the postprandial processes (i.e., digestion, absorption and assimilation of a meal; termed specific dynamic action (SDA at both temperatures. Larvae fed voraciously when provided with food for a 12-hour period and displayed a temperature-independent increase in mass of 40.1% (28.5°C and 42.6% (31.5°C, which was largely associated with the mass of prey in the gut. A subsequent 12-h fasting period revealed that the larvae had grown 21.2±4.8% (28.5°C and 22.8±8.8% (31.5°C in mass and 10.3±2.0% (28.5°C and 7.8±2.6% (31.5°C in length compared with pre-feeding values (no significant temperature effect. Mo2 routine was 55±16% higher at 31.5°C and peak Mo2 during the postprandial period was 28±11% higher at 31.5°C, yet elevated temperature had no significant effect on SDA (0.51±0.06 J at 28.5°C vs. 0.53±0.07 J at 31.5°C, SDA duration (6.0±0.6 h vs. 6.5±0.5 h, or the percent of total meal energy used for SDA (SDA coefficient: 10.1±1.3% vs. 13.0±1.7%. Our findings of higher Mo2 routine but similar SDA coefficient at high temperature provide the first empirical evidence that coral reef fish larvae may have to secure more food to attain similar growth rates during warm summer periods, and perhaps with chronically warmer conditions associated with climate change.

  16. Limited Capacity for Faster Digestion in Larval Coral Reef Fish at an Elevated Temperature. (United States)

    McLeod, Ian M; Clark, Timothy D


    The prevalence of extreme, short-term temperature spikes in coastal regions during summer months is predicted to increase with ongoing climate change. In tropical systems, these changes are predicted to increase the metabolic demand of coral reef fish larvae while also altering the plankton communities upon which the larvae feed during their pelagic phase. The consequences of these predictions remain speculative in the absence of empirical data on the interactive effects of warm temperatures on the metabolism, postprandial processes and growth responses of coral reef fish larvae. Here, we tested the effect of increased temperature on the metabolism, postprandial performance and fine-scale growth patterns of a coral reef fish (Amphiprion percula) in the latter half of its ~11-d larval phase. First, we measured the length and weight of fed versus fasted larvae (N = 340; mean body mass 4.1±0.05 mg) across fine temporal scales at a typical current summer temperature (28.5°C) and a temperature that is likely be encountered during warm summer periods later this century (31.5°C). Second, we measured routine metabolic rate (Mo2 routine) and the energetics of the postprandial processes (i.e., digestion, absorption and assimilation of a meal; termed specific dynamic action (SDA)) at both temperatures. Larvae fed voraciously when provided with food for a 12-hour period and displayed a temperature-independent increase in mass of 40.1% (28.5°C) and 42.6% (31.5°C), which was largely associated with the mass of prey in the gut. A subsequent 12-h fasting period revealed that the larvae had grown 21.2±4.8% (28.5°C) and 22.8±8.8% (31.5°C) in mass and 10.3±2.0% (28.5°C) and 7.8±2.6% (31.5°C) in length compared with pre-feeding values (no significant temperature effect). Mo2 routine was 55±16% higher at 31.5°C and peak Mo2 during the postprandial period was 28±11% higher at 31.5°C, yet elevated temperature had no significant effect on SDA (0.51±0.06 J at 28.5°C vs. 0.53±0.07 J at 31.5°C), SDA duration (6.0±0.6 h vs. 6.5±0.5 h), or the percent of total meal energy used for SDA (SDA coefficient: 10.1±1.3% vs. 13.0±1.7%). Our findings of higher Mo2 routine but similar SDA coefficient at high temperature provide the first empirical evidence that coral reef fish larvae may have to secure more food to attain similar growth rates during warm summer periods, and perhaps with chronically warmer conditions associated with climate change.

  17. Why do bubbles in Guinness sink? (United States)

    Benilov, E. S.; Cummins, C. P.; Lee, W. T.


    Stout beers show the counter-intuitive phenomena of sinking bubbles, while the beer is settling. Previous research suggests that this phenomenon is due to the small size of the bubbles in these beers and the presence of a circulatory current, directed downwards near the side of the wall and upwards in the interior of the glass. The mechanism by which such a circulation is established and the conditions under which it will occur has not been clarified. In this paper, we use simulations and experiments to demonstrate that the flow in a glass of stout beer depends on the shape of the glass. If it narrows downwards (as the traditional stout glass, the pint, does), the flow is directed downwards near the wall and upwards in the interior and sinking bubbles will be observed. If the container widens downwards, the flow is opposite to that described above and only rising bubbles will be seen.

  18. Source and sink nodes in absence seizures. (United States)

    Rodrigues, Abner C; Machado, Birajara S; Caboclo, Luis Otavio S F; Fujita, Andre; Baccala, Luiz A; Sameshima, Koichi


    As opposed to focal epilepsy, absence seizures do not exhibit a clear seizure onset zone or focus since its ictal activity rapidly engages both brain hemispheres. Yet recent graph theoretical analysis applied to absence seizures EEG suggests the cortical focal presence, an unexpected feature for this type of epilepsy. In this study, we explore the characteristics of absence seizure by classifying the nodes as to their source/sink natures via weighted directed graph analysis based on connectivity direction and strength estimation using information partial directed coherence (iPDC). By segmenting the EEG signals into relatively short 5-sec-long time windows we studied the evolution of coupling strengths from both sink and source nodes, and the network dynamics of absence seizures in eight patients.

  19. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to L-carnitine and faster recovery from muscle fatigue after exercise (ID 738, 1492, 1493), skeletal muscle tissue repair (ID 738, 1492, 1493), increase in endurance, capacity (ID 4305, 4684), maintenance of normal blood LDL-cholesterol concentrations (ID 1494, 4684), contribution to normal spermatogenesis (ID 1822), “energy metabolism” (ID 1821), and increasing L-carnitine concentrations and/or decreasing free fatty acids in blood during pregnancy (ID 1495) pursuant

    DEFF Research Database (Denmark)

    Tetens, Inge

    claims in relation to L-carnitine and faster recovery from muscle fatigue after exercise, skeletal muscle tissue repair, increase in endurance capacity, maintenance of normal blood LDL-cholesterol concentrations, contribution to normal spermatogenesis, “energy metabolism”, and increasing L-carnitine....... The food constituent that is the subject of the health claims is carnitine (as L-carnitine). The Panel considers that L-carnitine is sufficiently characterised.......Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on a list of health claims pursuant to Article 13 of Regulation (EC) No 1924/2006. This opinion addresses the scientific substantiation of health...

  20. Mine shaft sinking in recent decade

    Energy Technology Data Exchange (ETDEWEB)


    Between 1976 and 1985, 172 new shafts with a total depth of 74,166 m have been sunk in Chinese coal mines. Of the 172 new shafts, 89 were sunk by a conventional method while 83 were sunk by special shaft sinking methods. The shaft excavation technology and equipment in China is near to or has reached world advanced level. There are wide application of mechanisation and improvement in the various shaft excavation techniques. 3 tabs.

  1. 78 FR 21417 - Drawn Stainless Steel Sinks From China (United States)


    ... COMMISSION Drawn Stainless Steel Sinks From China Determinations On the basis of the record \\1\\ developed in... drawn stainless steel sinks from China, provided for in subheading 7324.10.00 of the Harmonized Tariff... notification of a preliminary determinations by Commerce that imports of drawn stainless steel sinks from China...

  2. Longevity of terrestrial Carbon sinks: effects of soil degradation on greenhouse gas emissions (United States)

    Kuhn, Nikolaus J.; Berger, Samuel; Kuonen, Samuel


    Soil erosion by water is a key process of soil and land degradation. In addition, significant amounts of nutrients and organic Carbon are moved from eroding source areas to landscape sinks. As a consequence, areas affected by erosion suffer a loss of fertility, while sinks experience the development of a stockpile of the deposited sediment, including soil organic matter and nutrients. The deposited nutrients are largely unavailable for the plants growing in these landscape sediment sinks once the thickness of the deposited layer is greater than the rooting depth of the plants. In addition, the deposited organic matter is decomposed slowly through the pack of sediment. At sites of erosion, nutrients have to be replaced and organic matter content of the soil declines due to a destruction of the A horizon. Over time, the risk of a significant reduction in productivity, for example caused by a loss of top soil with a sufficient water storage capacity for maximum plant growth, leads to a decline in CO2 uptake by photosynthesis. Soil organic matter at eroding sites therefore declines and consequently the sediment that is moved to landscape sinks also has a smaller organic matter content than sediment generated from the non-degraded soil. The sediment sinks, on the other hand, emit an increasing amount of greenhouse gases as a consequence of the increasing amount of organic matter deposited while the upslope area is eroded. Over time, the perceived sink effect of soil erosion for greenhouse gases is therefore replaced with a neutral or positive emission balance of erosion in agricultural landscapes. Such a switch from none or a negative emission balance of agricultural landscapes to a positive balance carries the risk of accelerating climate change. In this study, we tried to estimate the risk associated with ongoing soil degradation and closing landscape soil organic matter sinks. Currently observed global erosion rates were linked to known limitations of soil

  3. Cortex Matures Faster in Youths With Highest IQ (United States)

    ... NIH Cortex Matures Faster in Youths With Highest IQ Past Issues / Summer 2006 Table of Contents For ... on. Photo: Getty image (StockDisc) Youths with superior IQ are distinguished by how fast the thinking part ...

  4. An Optimization Model of Carbon Sinks in CDM Forestry Projects Based on Interval Linear Programming

    Directory of Open Access Journals (Sweden)

    Wenjin Zhao


    Full Text Available This study describes the first general optimization model for complex systems with uncertain parameters and decision variables represented as intervals in CDM forestry projects. We work through a specific example of the optimization method developed for a Clean Development Mechanism (CDM forestry project in Inner Mongolia, China. This model is designed to optimize the carbon sink capacity of the new forests, and can deal with uncertainties in the carbon sink capacity, average annual rainfall, ecological parameters, and biological characteristics of tree species. The uncertain inputs are presented in the form of intervals, as are several of the optimized output variables. Compared with the project’s originally recommended scheme, the optimized model will absorb and fix between 1,142 and 885,762 tonnes of extra carbon dioxide. Moreover, the ecological and environmental benefits of the project are also raised to various extents.

  5. Variation in heat sink shape for thermal analysis (United States)

    Wong, C. M.; Aziz, M. H. B. A.; Ong, N. R.; Alcain, J. B.; Sauli, Z.


    The concern about the thermal performance of microelectronics is on the increase due to recent over-heating induced failures which have led to product recalls. Removal of excess heat from microelectronic systems with the use of heat sinks could improve thermal efficiency of the system. The shape of the heat sink model with difference fin configuration has significant influence on cooling performances. This paper investigates the effect of change in heat sink geometry on an electronic package through COMSOL Multiphysics software as well as the thermal performance of difference heat sink geometry corresponding to various air inlet velocities. Based on this study, plate fin heat sink has better thermal performance than strip pin fin and circular pin fin heat sink due to less obstruction of the heat sink design.

  6. Nonuniform ocean acidification and attenuation of the ocean carbon sink (United States)

    Fassbender, Andrea J.; Sabine, Christopher L.; Palevsky, Hilary I.


    Surface ocean carbon chemistry is changing rapidly. Partial pressures of carbon dioxide gas (pCO2) are rising, pH levels are declining, and the ocean's buffer capacity is eroding. Regional differences in short-term pH trends primarily have been attributed to physical and biological processes; however, heterogeneous seawater carbonate chemistry may also be playing an important role. Here we use Surface Ocean CO2 Atlas Version 4 data to develop 12 month gridded climatologies of carbonate system variables and explore the coherent spatial patterns of ocean acidification and attenuation in the ocean carbon sink caused by rising atmospheric pCO2. High-latitude regions exhibit the highest pH and buffer capacity sensitivities to pCO2 increases, while the equatorial Pacific is uniquely insensitive due to a newly defined aqueous CO2 concentration effect. Importantly, dissimilar regional pH trends do not necessarily equate to dissimilar acidity ([H+]) trends, indicating that [H+] is a more useful metric of acidification.

  7. Global Modelling of the total OH reactivity: validation against measurements and atmospheric implications of the 'missing' sink (United States)

    Ferracci, Valerio; Archibald, Alexander T.; Pyle, John A.


    recently been studied in the laboratory. Results from the UM-UKCA model show that reaction with RO2 might represent a non-negligible OH sink in remote environments, but cannot reconcile field measurements of the total OH reactivity with the sum of the individual sinks. To address this, an unspecified additional sink was added to the model in a series of simulations reproducing different scenarios (e.g., different OH recycling probabilities through the oxidation of the additional sink) with a view to establishing the impact of the additional OH sink on the oxidative capacity of the lower atmosphere.

  8. Ethanol fuel improves pitfall traps through rapid sinking and death of captured orthopterans. (United States)

    Szinwelski, N; Yotoko, K S C; Solar, R; Seleme, L R; Sperber, C F


    The choice of killing solutions for pitfall traps can influence sampling and is highly dependent on the objectives of each study. It is becoming increasingly common, however, and is more environmentally friendly, to use the same organisms to extract information for different kinds of studies. The killing solution should, therefore, be able to sample local active organisms, as well as maintain the integrity of their organs, tissues, and macromolecules. In a previous work, we showed that using ethanol fuel as a killing solution maintains the integrity of the specimens and enhances the Orthoptera richness and abundance of samples. In the current study, we evaluated two explanations for this pattern. We set up a field experiment to test whether ethanol fuel is attractive for orthopterans, and we investigated in the laboratory whether individuals of Gryllus sp. sink or die faster in ethanol fuel than in other killing solutions. Our results allowed us to refute the hypotheses of attraction caused by ethanol fuel and showed that the higher sampling efficiency of ethanol fuel is directly linked to the specimens sinking and dying faster than in other killing solutions. Thus, in addition to taxonomic, anatomical, and molecular studies, we recommend ethanol fuel for sampling organisms active in the litter in ecological studies.


    Directory of Open Access Journals (Sweden)



    Full Text Available A total loss of all heat sinks is considered a severe accident with a low probability of occurrence. Following a total loss of all heat sinks, the degasser/condenser relief valves (DCRV become the sole means available for the depressurization of the primary heat transport system. If a nuclear power plant has a total loss of heat sinks accident, high-temperature steam and differential pressure between the primary heat transport system (PHTS and the steam generator (SG secondary side can cause a SG tube creep rupture. To protect the PHTS during a total loss of all heat sinks accident, a sufficient depressurization capability of the degasser/condenser relief valve and the SG tube integrity is very important. Therefore, an accurate estimation of the discharge through these valves is necessary to assess the impact of the PHTS overprotection and the SG tube integrity of the primary circuit. This paper describes the analysis of DCRV discharge capacity and the SG tube integrity under a total loss of all heat sink using the CATHENA code. It was found that the DCRV's discharge capacity is enough to protect the overpressure in the PHTS, and the SG tube integrity is maintained in a total loss of all heat accident.

  10. Steam Generator Tube Integrity Analysis of A Total Loss of all Heat Sinks Accident for Wolsong NPP Unit 1

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Heoksoon; Song, Taeyoung; Chi, Moongoo [Korea Htydro and Nuclear Power Co., Ltd., Daejeon (Korea, Republic of); Kim, Seoungrae [Nuclear Engineering Service and Solution, Daejeon (Korea, Republic of)


    A total loss of all heat sinks is considered a severe accident with a low probability of occurrence. Following a total loss of all heat sinks, the degasser/condenser relief valves (DCRV) become the sole means available for the depressurization of the primary heat transport system. If a nuclear power plant has a total loss of heat sinks accident, high-temperature steam and differential pressure between the primary heat transport system (PHTS) and the steam generator (SG) secondary side can cause a SG tube creep rupture. To protect the PHTS during a total loss of all heat sinks accident, a sufficient depressurization capability of the degasser/condenser relief valve and the SG tube integrity is very important. Therefore, an accurate estimation of the discharge through these valves is necessary to assess the impact of the PHTS overprotection and the SG tube integrity of the primary circuit. This paper describes the analysis of DCRV discharge capacity and the SG tube integrity under a total loss of all heat sink using the CATHENA code. It was found that the DCRV's discharge capacity is enough to protect the overpressure in the PHTS, and the SG tube integrity is maintained in a total loss of all heat accident.

  11. A faster switching regime for zenithal bistable nematic displays

    International Nuclear Information System (INIS)

    Rudin, J.


    A simpler and faster switching regime for Zenithal Bistable Nematic displays is reported. A cell, based on homeotropic alignment of nematic liquid crystal over a continuous blazed monograting on one surface, can be switched using bipolar pulses an order of magnitude faster than monopolar pulses of the same voltage. We propose that this regime relies on simple dielectric coupling to drive the cell into a higher energy state with a long pulse time, and the relaxation into a lower energy state after the creation of surface defects from a shorter applied pulse. Although flexoelectric effects are observed, they do not form the basis of state selection as was proposed for the monopolar pulses

  12. Geological characterization of the Prestige sinking area. (United States)

    Ercilla, Gemma; Córdoba, Diego; Gallart, Josep; Gràcia, Eulalia; Muñoz, Josep A; Somoza, Luis; Vázquez, Juan T; Vilas, Federico


    The tanker Prestige sank off NW Iberia on the 19th November 2002. The stern and bow of the Prestige wreck are located on the southwestern edge of the Galicia Bank, at 3565 m and 3830 m water depths, respectively. This bank is a structural high controlled by major faults with predominant N-S, NNE-SSW, and NNW-SEE trends. It is characterized by moderate to low seismic activity. The faults have controlled the local depositional architecture, deforming, fracturing, relocating and distributing sediments since the Valangian (early Cretaceous). The Prestige sinking area corresponds to an asymmetric half-graben structure with a N-S trend, which conditions the present-day morphology. The faulted flank outcrops and its activity and erosion have favoured the occurrence of mass-movements (slumps, slump debris, mass-flows and turbidity currents), building valleys and depositional lobes. Nearsurface sediments comprise mostly terrigenous and biogenous turbiditic muds and sands with a minor presence of hemipelagic muds, except on the fault scarp where pelagites predominate. Potential geological hazards resulting from tectonic and sedimentary processes affect almost the entire Prestige sinking area.

  13. Causes of sinks near Tucson, Arizona, USA (United States)

    Hoffmann, John P.; Pool, Donald R.; Konieczki, A. D.; Carpenter, Michael C.

    Land subsidence in the form of sinks has occurred on and near farmlands near Tucson, Pima County, Arizona, USA. The sinks occur in alluvial deposits along the flood plain of the Santa Cruz River, and have made farmlands dangerous and unsuitable for farming. More than 1700 sinks are confined to the flood plain of the Santa Cruz River and are grouped along two north-northwestward-trending bands that are approximately parallel to the river and other flood-plain drainages. An estimated 17,000m3 of sediment have been removed in the formation of the sinks. Thirteen trenches were dug to depths of 4-6m to characterize near-surface sediments in sink and nonsink areas. Sediments below about 2m included a large percentage of dispersive clays in sink areas. Sediments in nonsink areas contain a large component of medium- to coarse-grained, moderately to well sorted sand that probably fills a paleochannel. Electromagnetic surveys support the association of silts and clays in sink areas that are highly electrically conductive relative to sand in nonsink areas. Sinks probably are caused by the near-surface process of subsurface erosion of dispersive sediments along pre-existing cracks in predominantly silt and clay sediments. The pre-existing cracks probably result from desiccation or tension that developed during periods of water-table decline and channel incision during the past 100 years or in earlier periods. Résumé Des effondrements en forme d'entonnoir se sont produits sur et près d'exploitations agricoles de Pima (Arizona). Ces entonnoirs apparaissent dans les alluvions le long de la plaine d'inondation de la rivière Santa Cruz ; ils ont rendu ces terrains dangereux et inexploitables pour l'agriculture. Plus de 1700 entonnoirs existent dans la plaine d'inondation de la rivière Santa Cruz et sont groupés en deux bandes orientées nord-nord-ouest, approximativement parallèles à la rivière et aux autres chenaux de la plaine d'inondation. Un volume de sédiments estim

  14. Source-sink relationships in radish plant

    Directory of Open Access Journals (Sweden)

    Z. Starck


    Full Text Available The problem of source-sink relationships in di- and tetraploidal radish plants grown in. hydroponic cultures was investigated in two stages of their development: with intensively growing swollen hypocotyl and in the period of actively accumulating nutrients in the storage organ. It was found, that the proportion, between the mass of organs, their RGR and NAR was very similar in di- and tetraploidal populations, probably owing to a similar rate of photosynthesis and pattern of assimilates distribution. The high variability of swollen hypocotyls size is slightly correlated with the size of the whole aerial part and is not correlated with the rate of photosynthesis in leaves. Partial defoliation of radish plants did not affect the rate of photosynthesis of the remaining leaves. Only in the cotyledones the oldest donors of 14C-assimilates, a slight compensation of photosynthesis was reported. It may suggest, that the rate of photosynthesis in radish plants is not under the control of sink activity. The size of the storage organ have determined in some extent its attractive force and influenced the amount of 14C-assimilates exported from their donors. Translocation of photosynthates from the young, still growing leaves was conditioned mainly by their retention power. Therefore, in young radish plants cotyledons were the main donor of 14C-assimilates.

  15. Mechanisms and Control of Phloem Transport in Trees: Fast and Slow - Sink and Source (United States)

    Gessler, Arthur; Hagedorn, Frank; Galiano, Lucia; Schaub, Marcus; Joseph, Jobin; Arend, Matthias; Hommel, Robert; Kayler, Zachary


    Trees are large global stores of carbon that will be affected by increased carbon dioxide levels and climate change in the future. However, at present we cannot properly predict the carbon balance of forests as we lack knowledge on how plant physiological processes and especially the transport of carbon within the plant interact with environmental drivers and ecosystem-scale processes. The central conveyor belt for C allocation and distribution within the tree is the phloem and its functionality under environmental stress (esp. drought) is important for the avoidance of C starvation. This paper addresses the distribution of new assimilates within the plant, and sheds light on phloem transport mechanisms and transport control using 13C pulse labelling techniques. We provide experimental evidence that at least two mechanisms are employed to couple C sink processes to assimilation. We observed a fast increase of belowground respiration with the onset of photosynthesis, which we assume is induced by pressure concentration waves travelling through the phloem. A second, much later occurring peak in respiration is fueled by new 13C labeled assimilates. Moreover, we relate phloem transport velocity and intensity of labelled 13C assimilates to drought stress intensity and give indication how sink rather than source control might affect phloem transport in trees. During drought, net photosynthesis, soil respiration and the allocation of recent assimilates below ground were reduced. Carbohydrates accumulated in metabolically resting roots but not in leaves, indicating sink control of the tree carbon balance. After drought release, soil respiration recovered faster than assimilation and CO2 fluxes exceeded those in continuously watered trees for months. This stimulation was related to greater assimilate allocation to and metabolization in the rhizosphere. These findings show that trees prioritize the investment of assimilates below ground, probably to regain root functions

  16. The ocean carbon sink - impacts, vulnerabilities, and challenges (United States)

    Heinze, C.; Meyer, S.; Goris, N.; Anderson, L.; Steinfeldt, R.; Chang, N.; Le Quéré, C.; Bakker, D. C. E.


    Carbon dioxide (CO2) is, next to water vapour, considered to be the most important natural greenhouse gas on Earth. Rapidly rising atmospheric CO2 concentrations caused by human actions such as fossil-fuel burning, land-use change or cement production over the past 250 years have given cause for concern that changes in Earth's climate system may progress at a much faster pace and larger extent than during the past 20 000 years. Investigating global carbon cycle pathways and finding suitable mitigation strategies has, therefore, become of major concern in many research fields. The oceans have a key role in regulating atmospheric CO2 concentrations and currently take up about 25% of annual anthropogenic carbon emissions to the atmosphere. Questions that yet need to be answered are what the carbon uptake kinetics of the oceans will be in the future and how the increase in oceanic carbon load will affect its ecosystems and their services. This requires comprehensive investigations, including high-quality ocean carbon measurements on different spatial and temporal scales, the management of data in sophisticated data bases, the application of state-of-the-art Earth system models to provide future projections for given emission scenarios as well as a global synthesis and outreach to policy makers. In this paper, the current understanding of the ocean as an important carbon sink is reviewed with respect to these topics. Emphasis is placed on the complex interplay of different physical, chemical, and biological processes that yield both positive and negative air-sea flux values for natural and anthropogenic CO2 as well as on increased CO2 (uptake) as the regulating force of the radiative warming of the atmosphere and the gradual acidification of the oceans. Major future ocean carbon challenges in the fields of ocean observations, modelling, and process research as well as the relevance of other biogeochemical cycles and greenhouse gases are discussed.

  17. New analytical approaches for faster or greener phytochemical analyses

    NARCIS (Netherlands)

    Shen, Y.



    Chapter 1 provides a short introduction into the constraints of phytochemical analysis. In order to make them faster, less laborious and greener, there is a clear scope for miniaturized and simplified sample preparation, solvent-free extractions

  18. Increasing the Capital Income Tax Leads to Faster Growth

    NARCIS (Netherlands)

    Uhlig, H.F.H.V.S.; Yanagawa, N.


    This paper shows that under rather mild conditions, higher capital income taxes lead to faster growth in an overlapping generations economy with endogenous growth. Government expenditures are financed with labor income taxes as well as capital income taxes. Since capital income accrues to the old,

  19. Cooling characteristics of a strip fin heat sink

    International Nuclear Information System (INIS)

    Riu, Kap Jong; Park, Cheol Woo; Jang, Chung Sun; Kim, Hyun Woo


    Air-cooled heat sinks are employed in many electronic cooling applications since they provide significant heat transfer enhancement and operational flexibility. Strip-shaped fin heat sink is of interest and needs to be investigated as general cooling products for more applicability. The purposes of this study are to evaluate heat sink performance without bypass flow condition and to determine optimal heat sink geometries. The results show that the decreasing rate of thermal resistance of a heat sink decreases with increasing inlet air velocity, and the increasing rate of pressure drop increases with increasing inlet air velocity, but is not affected by input power. The increasing rate of optimal longitudinal fin spacing is larger than that of transverse fin spacing. The strip fin heat sink tested in this study showed better cooling performance compared to that of other plate fin type

  20. Forest Carbon Sinks and Biodiversity Conservation from China's Perspective


    Mingde Cao, Ying Chen


    The Kyoto Protocol established the use of forest carbon sinks as one way of compensating for forest ecological values. Forest carbon sinks can promote sustainable economic development and help developed nations reduce their GHG emissions. But without proper legal regulation they may influence the local ecological environment and, in particular, they may harm biodiversity. States need to make laws that regulate forest carbon sinks and protect biodiversity. Environmental law urgently needs to s...

  1. Structure emerges faster during cultural transmission in children than in adults. (United States)

    Kempe, Vera; Gauvrit, Nicolas; Forsyth, Douglas


    How does children's limited processing capacity affect cultural transmission of complex information? We show that over the course of iterated reproduction of two-dimensional random dot patterns transmission accuracy increased to a similar extent in 5- to 8-year-old children and adults whereas algorithmic complexity decreased faster in children. Thus, children require more structure to render complex inputs learnable. In line with the Less-Is-More hypothesis, we interpret this as evidence that children's processing limitations affecting working memory capacity and executive control constrain the ability to represent and generate complexity, which, in turn, facilitates emergence of structure. This underscores the importance of investigating the role of children in the transmission of complex cultural traits. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. The potential contribution of sinks to meeting Kyoto Protocol commitments

    DEFF Research Database (Denmark)

    Missfeldt, F.; Haites, E.


    scenario, at least some of the sinks have costs lower than the market price, so the larger the eligible sinks, the lower the compliance costs for industrialised countries. Greater use of sinks also reduces the net income received by the economies in transition and developing countries. Increased use......, a range of average costs is used with the lowest cost allowing maximum use of sinks. The effects considered are the impacts on compliance costs for OECD countries, economies in transition, and developing countries and the mix of actions used by industrialised countries to achieve compliance. In every...

  3. Effects of biofouling on the sinking behavior of microplastics (United States)

    Kaiser, David; Kowalski, Nicole; Waniek, Joanna J.


    Although plastic is ubiquitous in marine systems, our current knowledge of transport mechanisms is limited. Much of the plastic entering the ocean sinks; this is intuitively obvious for polymers such as polystyrene (PS), which have a greater density than seawater, but lower density polymers like polyethylene (PE) also occur in sediments. Biofouling can cause large plastic objects to sink, but this phenomenon has not been described for microplastics microplastic particles in estuarine and coastal waters to determine how biofouling changes their sinking behavior. Sinking velocities of PS increased by 16% in estuarine water (salinity 9.8) and 81% in marine water (salinity 36) after 6 weeks of incubation. Thereafter sinking velocities decreased due to lower water temperatures and reduced light availability. Biofouling did not cause PE to sink during the 14 weeks of incubation in estuarine water, but PE started to sink after six weeks in coastal water when sufficiently colonized by blue mussels Mytilus edulis, and its velocity continued to increase until the end of the incubation period. Sinking velocities of these PE pellets were similar irrespective of salinity (10 vs. 36). Biofilm composition differed between estuarine and coastal stations, presumably accounting for differences in sinking behavior. We demonstrate that biofouling enhances microplastic deposition to marine sediments, and our findings should improve microplastic transport models.

  4. Investigation of Heat Sink Efficiency for Electronic Component Cooling Applications

    DEFF Research Database (Denmark)

    Staliulionis, Ž.; Zhang, Zhe; Pittini, Riccardo


    of relatively simple heat sink application is performed using modeling based on finite element method, and also the potential of such analysis was demonstrated by real-world measurements and comparing obtained results. Thermal modeling was accomplished using finite element analysis software COMSOL and thermo-imaging......Research and optimisation of cooling of electronic components using heat sinks becomes increasingly important in modern industry. Numerical methods with experimental real-world verification are the main tools to evaluate efficiency of heat sinks or heat sink systems. Here the investigation...... camera was used to measure the thermal field distribution. Ideas for future research involving improvement of the experimental setup and modeling verification are given....

  5. Sink-source proximity affecting photosynthate distributive pattern in barley (Hordeum Vulgare L.)

    International Nuclear Information System (INIS)

    Nath-Kothiala, Neeta; Mishra, S.D.


    Yielding ability of cereals is an interplay of source-sink capacities and is controlled presumably by physiological events at different growth stages. The translocation of 14 C-sucrose from the flag leaf to the ears and other plant parts of the main tiller of barley (H. vulgare L. cv 292) were studied at its appearance (I), maturation (II) and senescence initiation (III) stages. At every stage, there was preferentially higher 14 C-translocation from the flag leaf to the ears in comparison to other plant parts, indicating thereby the crucial role played by sink-source proximity in PHS'ate(photosynthate) Partg(partitioning). In order to ascertain such Partg behaviour of the different leaves on the main tiller at stage-II, the leaves starting basipetally, from flag to the fifth leaf, were labelled with 14 C-sucrose and their relative translocation to the ears and roots were determined. There was a differential 14 C-translocation to the sinks due to the change in the sink-source proximity, viz. >90% 14 C were translocated to the ears from flag leaf, which declined to ≤5% only from the fifth leaf, the reverse being true for the roots. Further, spikelet's central grains preferentially accumulated more 14 C-assimilates than the peripheral ones, probably due to being in close proximity to the unloading points. Thus, the distributive pattern of photoassimilates showed stage-specific quantitative changes and that the sink-source proximity played a crucial role in the PHS'ate Partg. (author). 3 figs., 29 refs

  6. Sources and sinks of stratospheric water vapor

    International Nuclear Information System (INIS)

    Ellsaesser, H.W.


    A tutorial review of the understanding of stratospheric H 2 O and the processes controlling it is presented. Paradoxes posed by currently available observational data are cited and suggestions made as to how they might be resolved. Such resolution appears to require: that the bulk of our current data provides unrepresentative and misleading vertical and latitudinal H 2 O gradients immediately downstream from the tropical tropopause; and, that there exists within the troposphere a mechanism different from or in addition to the tropical tropopause cold trap for drying air to the mixing ratios found in the lower stratosphere. Satisfaction of these requirements will reconcile much heretofore puzzling observational data and will obviate the necessity for a stratospheric sink for H 2 O

  7. UHS, Ultimate Heat Sink Cooling Pond Analysis

    International Nuclear Information System (INIS)

    Codell, R.; Nuttle, W.K.


    1 - Description of program or function: Three programs model performance of an ultimate heat sink cooling pond. National Weather Service data is read and analyzed to predict periods of lowest cooling performance and highest evaporative loss. The data is compared to local site data for significant differences. Then the maximum pond temperature is predicted. Five programs model performance of an ultimate heat sink spray pond. The cooling performance, evaporative water loss, and drift water loss as a function of wind speed are estimated for a spray field. These estimates are used in conjunction with National Weather Service data to predict periods of lowest cooling performance and highest evaporative loss. This data is compared to local site data for significant differences. Then the maximum pond temperature is predicted. 2 - Method of solution: The transfer of heat and water vapor is modeled using an equilibrium temperature procedure for an UHS cooling pond. The UHS spray pond model considers heat, mass, and momentum transfer from a single water drop with the surrounding air, and modification of the surrounding air resulting from the heat, mass, and momentum transfer from many drops in different parts of a spray field. 3 - Restrictions on the complexity of the problem: The program SPRCO uses RANF, a uniform random number generator which is an intrinsic function on the CDC. All programs except COMET use the NAMELIST statement, which is non standard. Otherwise these programs conform to the ANSI Fortran 77 standard. The meteorological data scanning procedure requires tens of years of recorded data to be effective. The models and methods, provided as useful tool for UHS analyses of cooling ponds and spray ponds, are intended as guidelines only. Use of these methods does not automatically assure NRC approval, nor are they required procedures for nuclear-power-plant licensing

  8. Photosynthesis and sink activity of wasp-induced galls in Acacia pycnantha. (United States)

    Dorchin, Netta; Cramer, Michael D; Hoffmann, John H


    Although insect galls are widely known to influence source-sink relationships in plants, the relationship between photosynthesis and gall activity has not been extensively studied. In this study we used 14CO2, photosynthesis, and respiration measurements to examine the capacity of bud galls induced by the wasp Trichilogaster signiventris (Pteromalidae) as carbon sinks in Acacia pycnantha. Galls of this species develop either in vegetative or reproductive buds, depending on the availability of tissues at different times of the year, and effectively eliminate seed production by the plant. Photosynthetic rates in phyllodes subtending clusters of galls were greater than rates in control phyllodes, a result we attributed to photosynthesis compensating for increased carbon demand by the galls. Contrary to previous studies, we found that photosynthesis within galls contributed substantially to the carbon budgets of the galls, particularly in large, mature galls, which exhibited lower specific respiration rates allowing for a net carbon gain in the light. To determine the sink capacity and competitive potential of galls, we measured the proportion of specific radioactivity in galls originating from either vegetative or reproductive buds and found no difference between them. The proportion of the total amount of phyllode-derived 14C accumulated in both clustered and solitary galls was less than that in fruits. Galls and fruits were predominantly reliant on subtending rather than on distant phyllodes for photosynthate. Solitary galls that developed in vegetative buds constituted considerably stronger sinks than galls in clusters on inflorescences where there was competition between galls or fruits for resources from the subtending phyllode. Wasps developing in solitary vegetative galls were correspondingly significantly larger than those from clustered galls. We conclude that, in the absence of inflorescence buds during summer and fall, the ability of the wasps to cause gall

  9. Multiple Object Tracking Using the Shortest Path Faster Association Algorithm

    Directory of Open Access Journals (Sweden)

    Zhenghao Xi


    Full Text Available To solve the persistently multiple object tracking in cluttered environments, this paper presents a novel tracking association approach based on the shortest path faster algorithm. First, the multiple object tracking is formulated as an integer programming problem of the flow network. Then we relax the integer programming to a standard linear programming problem. Therefore, the global optimum can be quickly obtained using the shortest path faster algorithm. The proposed method avoids the difficulties of integer programming, and it has a lower worst-case complexity than competing methods but better robustness and tracking accuracy in complex environments. Simulation results show that the proposed algorithm takes less time than other state-of-the-art methods and can operate in real time.

  10. Adrenaline in cardiac arrest: Prefilled syringes are faster. (United States)

    Helm, Claire; Gillett, Mark


    Standard ampoules and prefilled syringes of adrenaline are widely available in Australasian EDs for use in cardiac arrest. We hypothesise that prefilled syringes can be administered more rapidly and accurately when compared with the two available standard ampoules. This is a triple arm superiority study comparing the time to i.v. administration and accuracy of dosing of three currently available preparations of adrenaline. In their standard packaging, prefilled syringes were on average more than 12 s faster to administer than the 1 mL 1:1000 ampoules and more than 16 s faster than the 10 mL 1:10,000 ampoules (P adrenaline utilising a Minijet (CSL Limited, Parkville, Victoria, Australia) is faster than using adrenaline in glass ampoules presented in their plastic packaging. Removing the plastic packaging from the 1 mL (1 mg) ampoule might result in more rapid administration similar to the Minijet. Resuscitation personnel requiring rapid access to adrenaline should consider storing it as either Minijets or ampoules devoid of packaging. These results might be extrapolatable to other clinical scenarios, including pre-hospital and anaesthesia, where other drugs are required for rapid use. © 2015 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

  11. 77 FR 23752 - Drawn Stainless Steel Sinks From China (United States)


    ... COMMISSION Drawn Stainless Steel Sinks From China Determinations On the basis of the record \\1\\ developed in... reason of imports from China of drawn stainless sinks, provided for in subheading 7324.10.00 of the... than fair value (LTFV) and subsidized by the Government of China. \\1\\ The record is defined in sec. 207...

  12. Copepods use chemical trails to find sinking marine snow aggregates

    DEFF Research Database (Denmark)

    Lombard, Fabien; Koski, Marja; Kiørboe, Thomas


    Copepods are major consumers of sinking marine particles and hence reduce the efficiency of the biological carbon pump. Their high abundance on marine snow suggests that they can detect sinking particles remotely. By means of laboratory observations, we show that the copepod Temora longicornis ca...

  13. Sinking in Quicksand: An Applied Approach to the Archimedes Principle (United States)

    Evans, G. M.; Evans, S. C.; Moreno-Atanasio, R.


    The objective of this paper is to present a laboratory experiment that explains the phenomenon of sinking in quicksand simulated as a fluidized bed. The paper demonstrates experimentally and theoretically that the proportion of a body that sinks in quicksand depends on the volume fraction of solids and the density of the body relative to the…

  14. Transcriptional profiling of mechanically and genetically sink-limited soybeans (United States)

    The absence of a reproductive sink causes physiological and morphological changes in soybean plants. These include increased accumulation of nitrogen and starch in the leaves and delayed leaf senescence. To identify transcriptional changes that occur in leaves of these sink-limited plants, we used R...

  15. Grain boundary strength as point defect sink strength

    International Nuclear Information System (INIS)

    Volobuev, A.V.; Gann, V.V.


    Sink strength of spherical grain boundary as an absolutely absorbing surface and as finite thickness wall consisting of the edge dislocations are considered. The values of the grain boundary sink strength are shown to be critically dependent on the point defect recombination degree

  16. Characterizing source-sink dynamics with genetic parentage assignments

    NARCIS (Netherlands)

    Peery, M. Zachariah; Beissinger, Steven R.; House, Roger F.; Berube, Martine; Hall, Laurie A.; Sellas, Anna; Palsboll, Per J.


    Source-sink dynamics have been suggested to characterize the population structure of many species, but the prevalence of source-sink systems in nature is uncertain because of inherent challenges in estimating migration rates among populations. Migration rates are often difficult to estimate directly

  17. Fire ants perpetually rebuild sinking towers (United States)

    Phonekeo, Sulisay; Mlot, Nathan; Monaenkova, Daria; Hu, David L.; Tovey, Craig


    In the aftermath of a flood, fire ants, Solenopsis invicta, cluster into temporary encampments. The encampments can contain hundreds of thousands of ants and reach over 30 ants high. How do ants build such tall structures without being crushed? In this combined experimental and theoretical study, we investigate the shape and rate of construction of ant towers around a central support. The towers are bell shaped, consistent with towers of constant strength such as the Eiffel tower, where each element bears an equal load. However, unlike the Eiffel tower, the ant tower is built through a process of trial and error, whereby failed portions avalanche until the final shape emerges. High-speed and novel X-ray videography reveal that the tower constantly sinks and is rebuilt, reminiscent of large multicellular systems such as human skin. We combine the behavioural rules that produce rafts on water with measurements of adhesion and attachment strength to model the rate of growth of the tower. The model correctly predicts that the growth rate decreases as the support diameter increases. This work may inspire the design of synthetic swarms capable of building in vertical layers.

  18. A Nonlinear Energy Sink with Energy Harvester (United States)

    Kremer, Daniel

    The transfer of energy between systems is a natural process, manifesting in many different ways. In engineering transferable energy can be considered wanted or unwanted. Specifically in mechanical systems, energy transfer can occur as unwanted vibrations, passing from a source to a receiver. In electrical systems, energy transfer can be desirable, where energy from a source may be used elsewhere. This work proposes a method to combine the two, converting unwanted mechanical energy into useable electrical energy. A nonlinear energy sink (NES) is a vibration absorber that passively localizes vibrational energy, removing mechanical energy from a primary system. Consisting of a mass-spring-damper such that the stiffness is essentially nonlinear, a NES can localize vibrational energy from a source and dissipate it through damping. Replacing the NES mass with a series of magnets surrounded by coils fixed to the primary mass, the dissipated energy can be directly converted to electrical energy. A NES with energy harvesting properties is constructed and introduced. The system parameters are identified, with the NES having an essentially cubic nonlinear stiffness. A transduction factor is quantified linking the electrical and mechanical systems. An analytic analysis is carried out studying the transient and harmonically excited response of the system. It is found that the energy harvesting does not reduce the vibrational absorption capabilities of the NES. The performance of the system in both transient and harmonically excited responses is found to be heavily influenced by input energies. The system is tested, with good match to analytic results.

  19. CSRtrack Faster Calculation of 3-D CSR Effects

    CERN Document Server

    Dohlus, Martin


    CSRtrack is a new code for the simulation of Coherent Synchrotron radiation effects on the beam dynamics of linear accelerators. It incorporates the physics of our previous code, TraFiC4, and adds new algorithms for the calculation of the CSR fields. A one-dimensional projected method allows quick estimates and a greens function method allows 3D calculations about ten times faster than with the `direct' method. The tracking code is written in standard FORTRAN77 and has its own parser for comfortable input of calculation parameters and geometry. Phase space input and the analysis of the traced particle distribution is done with MATLAB interface programs.

  20. Even Faster Web Sites Performance Best Practices for Web Developers

    CERN Document Server

    Souders, Steve


    Performance is critical to the success of any web site, and yet today's web applications push browsers to their limits with increasing amounts of rich content and heavy use of Ajax. In this book, Steve Souders, web performance evangelist at Google and former Chief Performance Yahoo!, provides valuable techniques to help you optimize your site's performance. Souders' previous book, the bestselling High Performance Web Sites, shocked the web development world by revealing that 80% of the time it takes for a web page to load is on the client side. In Even Faster Web Sites, Souders and eight exp

  1. Robustness of a bisimulation-type faster-than preorder

    Directory of Open Access Journals (Sweden)

    Katrin Iltgen


    Full Text Available TACS is an extension of CCS where upper time bounds for delays can be specified. Luettgen and Vogler defined three variants of bismulation-type faster-than relations and showed that they all three lead to the same preorder, demonstrating the robustness of their approach. In the present paper, the operational semantics of TACS is extended; it is shown that two of the variants still give the same preorder as before, underlining robustness. An explanation is given why this result fails for the third variant. It is also shown that another variant, which mixes old and new operational semantics, can lead to smaller relations that prove the same preorder.

  2. Natural Heat-Sinking Control Method for High-Speed Actuation of the SMA

    Directory of Open Access Journals (Sweden)

    Tamio Arai


    Full Text Available This paper describes two methodologies for increasing the actuation speed of the shape memory alloy (SMA actuator in ambient environment. The first method involves the implementation of a simple, light-weight heat sink, which consists only of a combination of an outer metal tube with the silicone grease, but able to cool the heated alloy effectively. The second method describes a high current pulse actuation that actuates the alloy fastly using pulses in the milliseconds order. We hypothesize that a fast actuation of the SMA results in small increase in temperature, due to energy transformation from heat energy to the kinetic energy in the SMA. This new heating method revolutionizes the actuation of the alloy for a significantly faster response.

  3. A large and persistent carbon sink in the world's forests (United States)

    Pan, Y.; Birdsey, R.A.; Fang, J.; Houghton, R.; Kauppi, P.E.; Kurz, W.A.; Phillips, O.L.; Shvidenko, A.; Lewis, S.L.; Canadell, J.G.; Ciais, P.; Jackson, R.B.; Pacala, S.W.; McGuire, A.D.; Piao, S.; Rautiainen, A.; Sitch, S.; Hayes, D.


    The terrestrial carbon sink has been large in recent decades, but its size and location remain uncertain. Using forest inventory data and long-term ecosystem carbon studies, we estimate a total forest sink of 2.4 ?? 0.4 petagrams of carbon per year (Pg C year-1) globally for 1990 to 2007. We also estimate a source of 1.3 ?? 0.7 Pg C year-1 from tropical land-use change, consisting of a gross tropical deforestation emission of 2.9 ?? 0.5 Pg C year-1 partially compensated by a carbon sink in tropical forest regrowth of 1.6 ?? 0.5 Pg C year-1. Together, the fluxes comprise a net global forest sink of 1.1 ?? 0.8 Pg C year-1, with tropical estimates having the largest uncertainties. Our total forest sink estimate is equivalent in magnitude to the terrestrial sink deduced from fossil fuel emissions and land-use change sources minus ocean and atmospheric sinks.

  4. A simple method to convert sink particles into stars (United States)

    Sormani, Mattia C.; Treß, Robin G.; Klessen, Ralf S.; Glover, Simon C. O.


    Hydrodynamical simulations of star formation often do not possess the dynamic range needed to fully resolve the build-up of individual stars and star clusters, and thus have to resort to sub-grid models. A popular way to do this is by introducing Lagrangian sink particles, which replace contracting high-density regions at the point where the resolution limit is reached. A common problem then is how to assign fundamental stellar properties to sink particles, such as the distribution of stellar masses. We present a new and simple statistical method to assign stellar contents to sink particles. Once the stellar content is specified, it can be used to determine a sink particle's radiative output, supernovae rate or other feedback parameters that may be required in the calculations. Advantages of our method are: (I) it is simple to implement; (II) it guarantees that the obtained stellar populations are good samples of the initial mass function; (III) it can easily deal with infalling mass accreted at later times; and (IV) it does not put restrictions on the sink particles' masses in order to be used. The method works very well for sink particles that represent large star clusters and for which the stellar mass function is well sampled, but can also handle the transition to sink particles that represent a small number of stars.

  5. Maximizing Lifetime of Wireless Sensor Networks with Mobile Sink Nodes

    Directory of Open Access Journals (Sweden)

    Yourong Chen


    Full Text Available In order to maximize network lifetime and balance energy consumption when sink nodes can move, maximizing lifetime of wireless sensor networks with mobile sink nodes (MLMS is researched. The movement path selection method of sink nodes is proposed. Modified subtractive clustering method, k-means method, and nearest neighbor interpolation method are used to obtain the movement paths. The lifetime optimization model is established under flow constraint, energy consumption constraint, link transmission constraint, and other constraints. The model is solved from the perspective of static and mobile data gathering of sink nodes. Subgradient method is used to solve the lifetime optimization model when one sink node stays at one anchor location. Geometric method is used to evaluate the amount of gathering data when sink nodes are moving. Finally, all sensor nodes transmit data according to the optimal data transmission scheme. Sink nodes gather the data along the shortest movement paths. Simulation results show that MLMS can prolong network lifetime, balance node energy consumption, and reduce data gathering latency under appropriate parameters. Under certain conditions, it outperforms Ratio_w, TPGF, RCC, and GRND.

  6. An Adaptive Clustering Approach Based on Minimum Travel Route Planning for Wireless Sensor Networks with a Mobile Sink (United States)

    Tang, Jiqiang; Yang, Wu; Zhu, Lingyun; Wang, Dong; Feng, Xin


    In recent years, Wireless Sensor Networks with a Mobile Sink (WSN-MS) have been an active research topic due to the widespread use of mobile devices. However, how to get the balance between data delivery latency and energy consumption becomes a key issue of WSN-MS. In this paper, we study the clustering approach by jointly considering the Route planning for mobile sink and Clustering Problem (RCP) for static sensor nodes. We solve the RCP problem by using the minimum travel route clustering approach, which applies the minimum travel route of the mobile sink to guide the clustering process. We formulate the RCP problem as an Integer Non-Linear Programming (INLP) problem to shorten the travel route of the mobile sink under three constraints: the communication hops constraint, the travel route constraint and the loop avoidance constraint. We then propose an Imprecise Induction Algorithm (IIA) based on the property that the solution with a small hop count is more feasible than that with a large hop count. The IIA algorithm includes three processes: initializing travel route planning with a Traveling Salesman Problem (TSP) algorithm, transforming the cluster head to a cluster member and transforming the cluster member to a cluster head. Extensive experimental results show that the IIA algorithm could automatically adjust cluster heads according to the maximum hops parameter and plan a shorter travel route for the mobile sink. Compared with the Shortest Path Tree-based Data-Gathering Algorithm (SPT-DGA), the IIA algorithm has the characteristics of shorter route length, smaller cluster head count and faster convergence rate. PMID:28445434

  7. Neuromuscular strategies contributing to faster multidirectional agility performance. (United States)

    Spiteri, Tania; Newton, Robert U; Nimphius, Sophia


    The aim of this study was to first determine differences in neuromuscular strategy between a faster and slower agility performance, and second compare differences in muscle activation strategy employed when performing two closely executed agility movements. Participants recruited from an elite female basketball team completed an ultrasound to determine quadriceps muscle-cross sectional area; reactive isometric mid-thigh pull to determine the rate of muscle activation, rate of force development, pre-motor time and motor time; and multidirectional agility tests completing two directional changes in response to a visual stimulus. Peak and average relative muscle activation of the rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinosus and gastrocnemius were measured 100ms prior to heel strike (pre-heel strike) and across stance phase for both directional changes. Faster agility performance was characterized by greater pre-heel strike muscle activity and greater anterior muscle activation during stance phase resulting in greater hip and knee extension increasing propulsive impulse. Differences between directional changes appear to result from processing speed, where a greater delay in refractory times during the second directional change resulted in greater anterior muscle activation, decelerating the body while movement direction was determined. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Faster quantum chemistry simulation on fault-tolerant quantum computers

    International Nuclear Information System (INIS)

    Cody Jones, N; McMahon, Peter L; Yamamoto, Yoshihisa; Whitfield, James D; Yung, Man-Hong; Aspuru-Guzik, Alán; Van Meter, Rodney


    Quantum computers can in principle simulate quantum physics exponentially faster than their classical counterparts, but some technical hurdles remain. We propose methods which substantially improve the performance of a particular form of simulation, ab initio quantum chemistry, on fault-tolerant quantum computers; these methods generalize readily to other quantum simulation problems. Quantum teleportation plays a key role in these improvements and is used extensively as a computing resource. To improve execution time, we examine techniques for constructing arbitrary gates which perform substantially faster than circuits based on the conventional Solovay–Kitaev algorithm (Dawson and Nielsen 2006 Quantum Inform. Comput. 6 81). For a given approximation error ϵ, arbitrary single-qubit gates can be produced fault-tolerantly and using a restricted set of gates in time which is O(log ϵ) or O(log log ϵ); with sufficient parallel preparation of ancillas, constant average depth is possible using a method we call programmable ancilla rotations. Moreover, we construct and analyze efficient implementations of first- and second-quantized simulation algorithms using the fault-tolerant arbitrary gates and other techniques, such as implementing various subroutines in constant time. A specific example we analyze is the ground-state energy calculation for lithium hydride. (paper)

  9. Safety and mission assurance in a better, faster, cheaper environment (United States)

    Gregory, Frederick D.


    To provide the American people with an exciting aeronautics and space program that provides more tangible value in products and services and more relevance to the public, NASA has developed a philosophy that emphasizes better, faster, and cheaper ways of conducting business. The integration of safety, reliability and quality assurance (SR&QA) products and services into all NASA's programs and projects, from beginning to end, and the implementation of progressive quality management and contracting practices are direct applications of this philosophy. NASA's new test effectiveness program integrates the oribital performance and reliability experience of prior spacecraft with new design processes and improved telemetry to achieve higher performance and reliability, faster, and at reduced cost. As United States government leaders for ISO 9000 implementation, NASA is promoting single quality systems for contractors, the use of advanced quality practices, and methods for the implementation of baseline quality systems with the appropriate oversight to further low cost, high performance programs in the future. To remain vital in today's era of fiscal constraint, NASA must be efficient, effective, and relevant. The innovative integration and application of SR&QA tools, techniques, and management approaches in all NASA's programs and projects will play an integral role in achieving this end.

  10. Implicit Negative Sub-Categorization and Sink Diversion for Object Detection. (United States)

    Li, Yu; Tang, Sheng; Lin, Min; Zhang, Yongdong; Li, Jintao; Yan, Shuicheng


    In this paper, we focus on improving the proposal classification stage in the object detection task and present implicit negative sub-categorization and sink diversion to lift the performance by strengthening loss function in this stage. First, based on the observation that the "background" class is generally very diverse and thus challenging to be handled as a single indiscriminative class in existing state-of-the-art methods, we propose to divide the background category into multiple implicit sub-categories to explicitly differentiate diverse patterns within it. Second, since the ground truth class inevitably has low-value probability scores for certain images, we propose to add a "sink" class and divert the probabilities of wrong classes to this class when necessary, such that the ground truth label will still have a higher probability than other wrong classes even though it has low probability output. Additionally, we propose to use dilated convolution, which is widely used in the semantic segmentation task, for efficient and valuable context information extraction. Extensive experiments on PASCAL VOC 2007 and 2012 data sets show that our proposed methods based on faster R-CNN implementation can achieve state-of-the-art mAPs, i.e., 84.1%, 82.6%, respectively, and obtain 2.5% improvement on ILSVRC DET compared with that of ResNet.

  11. ZKBoo: Faster Zero-Knowledge for Boolean Circuits

    DEFF Research Database (Denmark)

    Giacomelli, Irene; Madsen, Jesper; Orlandi, Claudio


    variants of IKOS, which highlights their pros and cons for practically rele- vant soundness parameters; ◦ A generalization and simplification of their approach, which leads to faster Σ-protocols (that can be made non-interactive using the Fiat-Shamir heuristic) for state- ments of the form “I know x...... such that y = φ (x)” (where φ is a circuit and y a public value); ◦ A case study, where we provide explicit protocols, implementations and benchmarking of zero-knowledge protocols for the SHA-1 and SHA-256 circuits.......In this paper we describe ZKBoo, a proposal for practically efficient zero-knowledge arguments especially tailored for Boolean circuits and report on a proof-of- concept implementation. As an highlight, we can generate (resp. verify) a non-interactive proof for the SHA-1 circuit in approximately 13...

  12. Climbing favours the tripod gait over alternative faster insect gaits (United States)

    Ramdya, Pavan; Thandiackal, Robin; Cherney, Raphael; Asselborn, Thibault; Benton, Richard; Ijspeert, Auke Jan; Floreano, Dario


    To escape danger or catch prey, running vertebrates rely on dynamic gaits with minimal ground contact. By contrast, most insects use a tripod gait that maintains at least three legs on the ground at any given time. One prevailing hypothesis for this difference in fast locomotor strategies is that tripod locomotion allows insects to rapidly navigate three-dimensional terrain. To test this, we computationally discovered fast locomotor gaits for a model based on Drosophila melanogaster. Indeed, the tripod gait emerges to the exclusion of many other possible gaits when optimizing fast upward climbing with leg adhesion. By contrast, novel two-legged bipod gaits are fastest on flat terrain without adhesion in the model and in a hexapod robot. Intriguingly, when adhesive leg structures in real Drosophila are covered, animals exhibit atypical bipod-like leg coordination. We propose that the requirement to climb vertical terrain may drive the prevalence of the tripod gait over faster alternative gaits with minimal ground contact.

  13. Genetic Algorithm Design of a 3D Printed Heat Sink

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tong [ORNL; Ozpineci, Burak [ORNL; Ayers, Curtis William [ORNL


    In this paper, a genetic algorithm- (GA-) based approach is discussed for designing heat sinks based on total heat generation and dissipation for a pre-specified size andshape. This approach combines random iteration processesand genetic algorithms with finite element analysis (FEA) to design the optimized heat sink. With an approach that prefers survival of the fittest , a more powerful heat sink can bedesigned which can cool power electronics more efficiently. Some of the resulting designs can only be 3D printed due totheir complexity. In addition to describing the methodology, this paper also includes comparisons of different cases to evaluate the performance of the newly designed heat sinkcompared to commercially available heat sinks.

  14. Efficient Information Dissemination in Wireless Sensor Networks using Mobile Sinks

    National Research Council Canada - National Science Library

    Vincze, Zoltan; Vidacs, Attila; Vida, Rolland


    ...; therefore, relaying information between sensors and a sink node, possibly over multiple wireless hops, in an energy-efficient manner is a challenging task that preoccupies the research community for some time now...

  15. DOE translation tool: Faster and better than ever

    International Nuclear Information System (INIS)

    El-Chakieh, T.; Vincent, C.


    CAE's constant push to advance power plant simulation practices involves continued investment in our technologies. This commitment has yielded many advances in our simulation technologies and tools to provide faster maintenance updates, easier process updates and higher fidelity models for power plant simulators. Through this quest, a comprehensive, self-contained and user-friendly DCS translation tool for plant control system emulation was created. The translation tool converts an ABB Advant AC160 and/or AC450 control system, used in both gas turbine-based, fossil and nuclear power plants, into Linux or Windows-based ROSE[reg] simulation schematics. The translation for a full combined-cycle gas turbine (CCGT) plant that comprises more than 5,300 function plans distributed over 15 nodes is processed in less than five hours on a dual 2.8Ghz Xeon Linux platform in comparison to the 12 hours required by CAE's previous translation tool. The translation process, using the plant configuration files, includes the parsing of the control algorithms, the databases, the graphic and the interconnection between nodes. A Linux or Windows API is then used to automatically populate the ROSE[reg] database. Without such a translation, tool or if ?stimulation? of real control system is not feasible or too costly, simulation of the DCS manually takes months of error prone manual coding. The translation can be performed for all the nodes constituting the configuration files of the whole plant DCS, or in order to provide faster maintenance updates and easier process updates, partial builds are possible at 3 levels: a. single schematic updates, b. multi-schematic updates and c. single node updates based on the user inputs into the Graphical User Interface. improvements including: - Process time reduction of over 60%; - All communication connections between nodes are fully automated; - New partial build for one schematic, a group of schematics or a single node; - Availability on PC

  16. Why genes evolve faster on secondary chromosomes in bacteria.

    Directory of Open Access Journals (Sweden)

    Vaughn S Cooper


    Full Text Available In bacterial genomes composed of more than one chromosome, one replicon is typically larger, harbors more essential genes than the others, and is considered primary. The greater variability of secondary chromosomes among related taxa has led to the theory that they serve as an accessory genome for specific niches or conditions. By this rationale, purifying selection should be weaker on genes on secondary chromosomes because of their reduced necessity or usage. To test this hypothesis we selected bacterial genomes composed of multiple chromosomes from two genera, Burkholderia and Vibrio, and quantified the evolutionary rates (dN and dS of all orthologs within each genus. Both evolutionary rate parameters were faster among orthologs found on secondary chromosomes than those on the primary chromosome. Further, in every bacterial genome with multiple chromosomes that we studied, genes on secondary chromosomes exhibited significantly weaker codon usage bias than those on primary chromosomes. Faster evolution and reduced codon bias could in turn result from global effects of chromosome position, as genes on secondary chromosomes experience reduced dosage and expression due to their delayed replication, or selection on specific gene attributes. These alternatives were evaluated using orthologs common to genomes with multiple chromosomes and genomes with single chromosomes. Analysis of these ortholog sets suggested that inherently fast-evolving genes tend to be sorted to secondary chromosomes when they arise; however, prolonged evolution on a secondary chromosome further accelerated substitution rates. In summary, secondary chromosomes in bacteria are evolutionary test beds where genes are weakly preserved and evolve more rapidly, likely because they are used less frequently.

  17. Cost Estimates Of Concentrated Photovoltaic Heat Sink Production (United States)


    water heating , but the majority of installed solar systems , are PV (EIA, 2015). Solar power generation has great benefits for the DON considering the...Current CPV systems use basic heat sink designs to increase efficiency. Modern heat sink design can achieve greater overall efficiencies of electricity...professionally developed cost analysis of adding optimized cooling technologies to concentrated photovoltaic (CPV) systems . Current CPV systems use basic heat

  18. A large and persistent carbon sink in the world's forests (United States)

    Yude Pan; Richard A. Birdsey; Jingyun Fang; Richard Houghton; Pekka E. Kauppi; Werner A. Kurz; Oliver L. Phillips; Anatoly Shvidenko; Simon L. Lewis; Josep G. Canadell; Philippe Ciais; Robert B. Jackson; Stephen W. Pacala; A. David McGuire; Shilong Piao; Aapo Rautiainen; Stephen Sitch; Daniel. Hayes


    The terrestrial carbon sink has been large in recent decades, but its size and location remain uncertain. Using forest inventory data and long-term ecosystem carbon studies, we estimate a total forest sink of 2.4 ± 0.4 petagrams of carbon per year (Pg C year-1) globally for 1990 to 2007. We also estimate a source of 1.3 ± 0.7 Pg...

  19. Innovations for competitiveness: European views on "better-faster-cheaper" (United States)

    Atzei, A.; Groepper, P.; Novara, M.; Pseiner, K.


    The paper elaborates on " lessons learned" from two recent ESA workshops, one focussing on the role of Innovation in the competitiveness of the space sector and the second on technology and engineering aspects conducive to better, faster and cheaper space programmes. The paper focuses primarily on four major aspects, namely: a) the adaptations of industrial and public organisations to the global market needs; b) the understanding of the bottleneck factors limiting competitiveness; c) the trends toward new system architectures and new engineering and production methods; d) the understanding of the role of new technology in the future applications. Under the pressure of market forces and the influence of many global and regional players, applications of space systems and technology are becoming more and more competitive. It is well recognised that without major effort for innovation in industrial practices, organisations, R&D, marketing and financial approaches the European space sector will stagnate and loose its competence as well as its competitiveness. It is also recognised that a programme run according to the "better, faster, cheaper" philosophy relies on much closer integration of system design, development and verification, and draws heavily on a robust and comprehensive programme of technology development, which must run in parallel and off-line with respect to flight programmes. A company's innovation capabilities will determine its future competitive advantage (in time, cost, performance or value) and overall growth potential. Innovation must be a process that can be counted on to provide repetitive, sustainable, long-term performance improvements. As such, it needs not depend on great breakthroughs in technology and concepts (which are accidental and rare). Rather, it could be based on bold evolution through the establishment of know-how, application of best practices, process effectiveness and high standards, performance measurement, and attention to

  20. Population growth and earth's human carrying capacity. (United States)

    Cohen, J E


    Earth's capacity to support people is determined both by natural constraints and by human choices concerning economics, environment, culture (including values and politics), and demography. Human carrying capacity is therefore dynamic and uncertain. Human choice is not captured by ecological notions of carrying capacity that are appropriate for nonhuman populations. Simple mathematical models of the relation between human population growth and human carrying capacity can account for faster-than-exponential population growth followed by a slowing population growth rate, as observed in recent human history.

  1. A Lifetime Optimization Algorithm Limited by Data Transmission Delay and Hops for Mobile Sink-Based Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Yourong Chen


    Full Text Available To improve the lifetime of mobile sink-based wireless sensor networks and considering that data transmission delay and hops are limited in actual system, a lifetime optimization algorithm limited by data transmission delay and hops (LOA_DH for mobile sink-based wireless sensor networks is proposed. In LOA_DH, some constraints are analyzed, and an optimization model is proposed. Maximum capacity path routing algorithm is used to calculate the energy consumption of communication. Improved genetic algorithm which modifies individuals to meet all constraints is used to solve the optimization model. The optimal solution of sink node’s sojourn grid centers and sojourn times which maximizes network lifetime is obtained. Simulation results show that, in three node distribution scenes, LOA_DH can find the movement solution of sink node which covers all sensor nodes. Compared with MCP_RAND, MCP_GMRE, and EASR, the solution improves network lifetime and reduces average amount of node discarded data and average energy consumption of nodes.

  2. Globalization of behavioral risks needs faster diffusion of interventions. (United States)

    Ebrahim, Shahul; Garcia, Joxel; Sujudi, Achmed; Atrash, Hani


    International trade, population migration, changes in living conditions (i.e., consumption transition, nutritional transition), and changes in production, marketing, and availability of consumer goods (i.e., production transition) have brought about continuous and rapid changes in the human environment. Such changes have improved the health and economic status of many people in developing countries. At the same time, a parallel phenomenon is occurring: the rapid emergence and expansion of modifiable risk behaviors. These behaviors adversely affect the national health of developing countries and that of future generations because of their impact on maternal, child, and adolescent health. Furthermore, these behaviors are increasing at a faster rate than interventions to curb their growth are being implemented. We discuss the current status of five modifiable risk behaviors--alcohol consumption, tobacco use, overweight and obesity, low fruit and vegetable consumption, and physical inactivity--to emphasize the need for global advocacy and local action to enhance policy formulation and diffusion of interventions necessary to moderate the spread of these behaviors.

  3. A piece of paper falling faster than free fall

    International Nuclear Information System (INIS)

    Vera, F; Rivera, R


    We report a simple experiment that clearly demonstrates a common error in the explanation of the classic experiment where a small piece of paper is put over a book and the system is let fall. This classic demonstration is used in introductory physics courses to show that after eliminating the friction force with the air, the piece of paper falls with acceleration g. To test if the paper falls behind the book in a nearly free fall motion or if it is dragged by the book, we designed a version of this experiment that includes a ball and a piece of paper over a book that is forced to fall using elastic cords. We recorded a video of our experiment using a high-speed video camera at 300 frames per second that shows that the book and the paper fall faster than the ball, which falls well behind the book with an acceleration approximately equal to g. Our experiment shows that the piece of paper is dragged behind the book and therefore the paper and book demonstration should not be used to show that all objects fall with acceleration g independently of their mass.

  4. Bird on Your Smartphone: How to make identification faster? (United States)

    Hidayat, T.; Kurniawan, I. S.; Tapilow, F. S.


    Identification skills of students are needed in the field activities of animal ecology course. Good identification skills will help students to understand the traits, determine differences and similarities in order to naming of birds’ species. This study aims to describe the identification skill of students by using smart phone applications designed in such a way as a support in the field activities. Research method used was quasi experiment involving 60 students which were divided into two groups, one group that use smartphone applications (SA) and other group using a guidebook (GB). This study was carried out in the classroom and outside (the field). Instruments used in this research included tests and questionnaire. The identification skills were measured by tests, indicated by an average score (AS). The results showed that the identification skills of SA students were higher (AS = 3.12) than those of GB one (AS = 2.91). These results are in accordance with response of students. The most of students (90.08%) mentioned that the use of smart phone applications in identifying birds is helpful, more effective and convenience to make identification faster. For further implementation, however, performance of the smartphone used here need to be enhanced to improve the identification skills of students and for wider use.

  5. Musicians react faster and are better multisensory integrators. (United States)

    Landry, Simon P; Champoux, François


    The results from numerous investigations suggest that musical training might enhance how senses interact. Despite repeated confirmation of anatomical and structural changes in visual, tactile, and auditory regions, significant changes have only been reported in the audiovisual domain and for the detection of audio-tactile incongruencies. In the present study, we aim at testing whether long-term musical training might also enhance other multisensory processes at a behavioural level. An audio-tactile reaction time task was administrated to a group of musicians and non-musicians. We found significantly faster reaction times with musicians for auditory, tactile, and audio-tactile stimulations. Statistical analyses between the combined uni- and multisensory reaction times revealed that musicians possess a statistical advantage when responding to multisensory stimuli compared to non-musicians. These results suggest for the first time that long-term musical training reduces simple non-musical auditory, tactile, and multisensory reaction times. Taken together with the previous results from other sensory modalities, these results strongly point towards musicians being better at integrating the inputs from various senses. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Learning Faster by Discovering and Exploiting Object Similarities

    Directory of Open Access Journals (Sweden)

    Tadej Janež


    Full Text Available In this paper we explore the question: “Is it possible to speed up the learning process of an autonomous agent by performing experiments in a more complex environment (i.e., an environment with a greater number of different objects?” To this end, we use a simple robotic domain, where the robot has to learn a qualitative model predicting the change in the robot's distance to an object. To quantify the environment's complexity, we defined cardinal complexity as the number of objects in the robot's world, and behavioural complexity as the number of objects' distinct behaviours. We propose Error reduction merging (ERM, a new learning method that automatically discovers similarities in the structure of the agent's environment. ERM identifies different types of objects solely from the data measured and merges the observations of objects that behave in the same or similar way in order to speed up the agent's learning. We performed a series of experiments in worlds of increasing complexity. The results in our simple domain indicate that ERM was capable of discovering structural similarities in the data which indeed made the learning faster, clearly superior to conventional learning. This observed trend occurred with various machine learning algorithms used inside the ERM method.

  7. Carrying Capacity

    DEFF Research Database (Denmark)

    Schroll, Henning; Andersen, Jan; Kjærgård, Bente


    A spatial planning act was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive....../cities. Four different sectors (water, food production, waste, and forests) were selected as core areas for decentralised spatial planning. Indicators for SCC and ACC were identified and assessed with regard to relevance and quantifiability. For each of the indicators selected, a legal threshold or guiding...... was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive carrying capacity (SCC) and assimilative...

  8. Carbon sink activity is stronger under grazing than under mowing: results from a paired eddy flux towers experiment (United States)

    Pintér, Krisztina; Balogh, János; Koncz, Péter; Hidy, Dóra; Cserhalmi, Dóra; Papp, Marianna; Fóti, Szilvia; Nagy, Zoltán


    Effect of grazing vs. mowing on carbon balance of a grassland was investigated by a paired eddy towers (one of them measuring the grazed, the another the mowed treatment) experiment at the Bugacpuszta sandy grassland site (HU-Bug, 46.69° N, 19.6° E, 114m asl, 10.4 ° C annual mean temperature, 562 mm annual precipitation sum) located in the Hungarian Plain. Eddy covariance measurements started in July, 2002. The area of the mowed treatment is 1 ha, it is located within the grazed treatment (500 ha). Electric fence was set up around the selected area in spring of 2011. Study years include 2011, 2012 and 2013. The pasture is managed extensively (average grazing pressure of 0.5 cattle per hectare), the cattle herd regularly took several kilometres during a grazing day. Annual net ecosystem exchange (NEE) of the grassland is strongly limited by precipitation, there were 2 source years within the 11 years (2003-2013) of measurements, during which the average annual balance was -109 gCm-2year-1 with standard deviation of 106 gCm-2year-1. Carbon sink activity of the grassland was stronger in the grazed treatment than in the mowed treatment during the three year study period (paired t-test, P=0.058). In the grazed treatment the average sink strength was -142.8 ±40 gCm-2year-1, while in the mowed treatment the average sink strength was -61.5 ±46.5 gCm-2year-1. Differences of carbon balances between the treatments were positively correlated to the annual sum of evapotranspiration (ET), while ETs of the treatments were almost identical (differences within a 10mm year-1 range) in each study year. Water use efficiency in the mowed treatment was 44% of that in the grazed treatment (P=0.045) as a result of the differences in sink capacity. The higher sensitivity to drought by the mowed treatment manifested in decreased sink capacity during summer and in decreased regeneration capacity during autumn rains as shown by the cumulative NEE in the different years. Minor but

  9. New models for estimating the carbon sink capacity of Spanish softwood species

    International Nuclear Information System (INIS)

    Ruiz-Peinado, R.; Rio, M. del; Montero, G.


    Quantifying the carbon balance in forests is one of the main challenges in forest management. Forest carbon stocks are usually estimated indirectly through biomass equations applied to forest inventories, frequently considering different tree biomass components. The aim of this study is to develop systems of equations for predicting tree biomass components for the main forest softwood species in Spain: Abies alba Mill., A. pinsapo Boiss., Juniperus thurifera L., Pinus canariensis Sweet ex Spreng., P. halepensis Mill., P. nigra Arn., P. pinaster Ait., P. pinea L., P. sylvestris L., P. uncinata Mill. For each species, a system of additive biomass models was fitted using seemingly unrelated regression. Diameter at the breast height and total height were used as independent variables. Diameter appears in all component models, while tree height was included in the stem component model of all species and in some branch component equations. Total height was included in order to improve biomass estimations at different sites. These biomass models were compared to previously available equations in order to test their accuracy and it was found that they yielded better fitting statistics in all cases. Moreover, the models fulfil the additivity property. We also developed root:shoot ratios in order to determine the partitioning into aboveground and belowground biomass. A number of differences were found between species, with a minimum of 0.183 for A. alba and a maximum of 0.385 for P. uncinata. The mean value for the softwood species studied was 0.265. Since the Spanish National Forest Inventory (NFI) records species, tree diameter and height of sample trees, these biomass models and ratios can be used to accurately estimate carbon stocks from NFI data. (Author) 55 refs.

  10. New models for estimating the carbon sink capacity of Spanish softwood species

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Peinado, R.; Rio, M. del; Montero, G.


    Quantifying the carbon balance in forests is one of the main challenges in forest management. Forest carbon stocks are usually estimated indirectly through biomass equations applied to forest inventories, frequently considering different tree biomass components. The aim of this study is to develop systems of equations for predicting tree biomass components for the main forest softwood species in Spain: Abies alba Mill., A. pinsapo Boiss., Juniperus thurifera L., Pinus canariensis Sweet ex Spreng., P. halepensis Mill., P. nigra Arn., P. pinaster Ait., P. pinea L., P. sylvestris L., P. uncinata Mill. For each species, a system of additive biomass models was fitted using seemingly unrelated regression. Diameter at the breast height and total height were used as independent variables. Diameter appears in all component models, while tree height was included in the stem component model of all species and in some branch component equations. Total height was included in order to improve biomass estimations at different sites. These biomass models were compared to previously available equations in order to test their accuracy and it was found that they yielded better fitting statistics in all cases. Moreover, the models fulfil the additivity property. We also developed root:shoot ratios in order to determine the partitioning into aboveground and belowground biomass. A number of differences were found between species, with a minimum of 0.183 for A. alba and a maximum of 0.385 for P. uncinata. The mean value for the softwood species studied was 0.265. Since the Spanish National Forest Inventory (NFI) records species, tree diameter and height of sample trees, these biomass models and ratios can be used to accurately estimate carbon stocks from NFI data. (Author) 55 refs.

  11. Phase Change Material Heat Sink for an ISS Flight Experiment (United States)

    Quinn, Gregory; Stieber, Jesse; Sheth, Rubik; Ahlstrom, Thomas


    A flight experiment is being constructed to utilize the persistent microgravity environment of the International Space Station (ISS) to prove out operation of a microgravity compatible phase change material (PCM) heat sink. A PCM heat sink can help to reduce the overall mass and volume of future exploration spacecraft thermal control systems (TCS). The program is characterizing a new PCM heat sink that incorporates a novel phase management approach to prevent high pressures and structural deformation that often occur with PCM heat sinks undergoing cyclic operation in microgravity. The PCM unit was made using brazed aluminum construction with paraffin wax as the fusible material. It is designed to be installed into a propylene glycol and water cooling loop, with scaling consistent with the conceptual designs for the Orion Multipurpose Crew Vehicle. This paper reports on the construction of the PCM heat sink and on initial ground test results conducted at UTC Aerospace Systems prior to delivery to NASA. The prototype will be tested later on the ground and in orbit via a self-contained experiment package developed by NASA Johnson Space Center to operate in an ISS EXPRESS rack.

  12. Station Capacity

    DEFF Research Database (Denmark)

    Landex, Alex


    the probability of conflicts and the minimum headway times into account. The last method analyzes how optimal platform tracks are used by examining the arrival and departure pattern of the trains. The developed methods can either be used separately to analyze specific characteristics of the capacity of a station...

  13. Faster Evolving Primate Genes Are More Likely to Duplicate. (United States)

    O'Toole, Áine N; Hurst, Laurence D; McLysaght, Aoife


    An attractive and long-standing hypothesis regarding the evolution of genes after duplication posits that the duplication event creates new evolutionary possibilities by releasing a copy of the gene from constraint. Apparent support was found in numerous analyses, particularly, the observation of higher rates of evolution in duplicated as compared with singleton genes. Could it, instead, be that more duplicable genes (owing to mutation, fixation, or retention biases) are intrinsically faster evolving? To uncouple the measurement of rates of evolution from the determination of duplicate or singleton status, we measure the rates of evolution in singleton genes in outgroup primate lineages but classify these genes as to whether they have duplicated or not in a crown group of great apes. We find that rates of evolution are higher in duplicable genes prior to the duplication event. In part this is owing to a negative correlation between coding sequence length and rate of evolution, coupled with a bias toward smaller genes being more duplicable. The effect is masked by difference in expression rate between duplicable genes and singletons. Additionally, in contradiction to the classical assumption, we find no convincing evidence for an increase in dN/dS after duplication, nor for rate asymmetry between duplicates. We conclude that high rates of evolution of duplicated genes are not solely a consequence of the duplication event, but are rather a predictor of duplicability. These results are consistent with a model in which successful gene duplication events in mammals are skewed toward events of minimal phenotypic impact. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  14. Shampoo-clay heals diaper rash faster than calendula officinalis. (United States)

    Adib-Hajbaghery, Mohsen; Mahmoudi, Mansoreh; Mashaiekhi, Mahdi


    Diaper rash is one of the most common skin disorders of infancy and childhood. Some studies have shown that Shampoo-clay was effective to treat chronic dermatitis. Then, it is supposed that it may be effective in diaper rash; however, no published studies were found in this regard. This study aimed to compare the effects of Shampoo-clay (S.C) and Calendula officinalis (C.O) to improve infantile diaper rash. A randomized, double blind, parallel controlled, non-inferiority trial was conducted on 60 outpatient infants referred to health care centers or pediatric clinics in Khomein city and diagnosed with diaper rash. Patients were randomly assigned into two treatment groups including S.C group (n = 30) and C.O group (n = 30) by using one to one allocation ratio. The rate of complete recovery in three days was the primary outcome. Data was collected using a checklist and analyzed using t-test, Chi-square and Fisher's exact tests and risk ratio. Totally, 93.3% of lesions in the S.C group healed in the first 6 hours, while this rate was 40% in C.O group (P < 0.001). The healing ratio for improvement in the first 6 hours was 7 times more in the S.C group. In addition, 90% of infants in the SC group and 36.7% in the C.O group were improved completely in the first 3 days (P < 0.001). S.C was effective to heal diaper rash, and also had faster effects compared to C.O.

  15. Review of tribological sinks in six major industries

    Energy Technology Data Exchange (ETDEWEB)

    Imhoff, C.H.; Brown, D.R.; Hane, G.J.; Hutchinson, R.A.; Erickson, R.; Merriman, T.; Gruber, T.; Barber, S.


    Friction and material wear occur throughout all industries and are involved in many processes within each industry. These conditions make assessing tribological activity overall in industry very complex and expensive. Therefore, a research strategy to obtain preliminary information on only the most significant industrial tribological sinks was defined. The industries examined were selected according to both the magnitude of overall energy consumption (particularly machine drive) and the known presence of significant tribological sinks. The six industries chosen are as follows: mining, agriculture, primary metals, chemicals/refining, food, and pulp and paper. They were reviewed to identify and characterize the major tribology sinks. It was concluded that wear losses are greater than friction losses, and that reducing wear rates would improve industrial productivity.

  16. Passive sinking into the snow as possible survival strategy during the off-host stage in an insect ectoparasite. (United States)

    Kaunisto, Sirpa; Ylonen, Hannu; Kortet, Raine


    Abiotic and biotic factors determine success or failure of individual organisms, populations and species. The early life stages are often the most vulnerable to heavy mortality due to environmental conditions. The deer ked (Lipoptena cervi Linnaeus, 1758) is an invasive insect ectoparasite of cervids that spends an important period of the life cycle outside host as immobile pupa. During winter, dark-coloured pupae drop off the host onto the snow, where they are exposed to environmental temperature variation and predation as long as the new snowfall provides shelter against these mortality factors. The other possible option is to passively sink into the snow, which is aided by morphology of pupae. Here, we experimentally studied passive snow sinking capacity of pupae of L. cervi. We show that pupae have a notable passive snow sinking capacity, which is the most likely explained by pupal morphology enabling solar energy absorption and pupal weight. The present results can be used when planning future studies and when evaluating possible predation risk and overall survival of this invasive ectoparasite species in changing environmental conditions.

  17. Land plants drive photorespiration as higher electron-sink: comparative study of post-illumination transient O2 -uptake rates from liverworts to angiosperms through ferns and gymnosperms. (United States)

    Hanawa, Hitomi; Ishizaki, Kimitsune; Nohira, Kana; Takagi, Daisuke; Shimakawa, Ginga; Sejima, Takehiro; Shaku, Keiichiro; Makino, Amane; Miyake, Chikahiro


    In higher plants, the electron-sink capacity of photorespiration contributes to alleviation of photoinhibition by dissipating excess energy under conditions when photosynthesis is limited. We addressed the question at which point in the evolution of photosynthetic organisms photorespiration began to function as electron sink and replaced the flavodiiron proteins which catalyze the reduction of O 2 at photosystem I in cyanobacteria. Algae do not have a higher activity of photorespiration when CO 2 assimilation is limited, and it can therefore not act as an electron sink. Using land plants (liverworts, ferns, gymnosperms, and angiosperms) we compared photorespiration activity and estimated the electron flux driven by photorespiration to evaluate its electron-sink capacity at CO 2 -compensation point. In vivo photorespiration activity was estimated by the simultaneous measurement of O 2 -exchange rate and chlorophyll fluorescence yield. All C3-plants leaves showed transient O 2 -uptake after actinic light illumination (post-illumination transient O 2 -uptake), which reflects photorespiration activity. Post-illumination transient O 2 -uptake rates increased in the order from liverworts to angiosperms through ferns and gymnosperms. Furthermore, photorespiration-dependent electron flux in photosynthetic linear electron flow was estimated from post-illumination transient O 2 -uptake rate and compared with the electron flux in photosynthetic linear electron flow in order to evaluate the electron-sink capacity of photorespiration. The electron-sink capacity at the CO 2 -compensation point also increased in the above order. In gymnosperms photorespiration was determined to be the main electron-sink. C3-C4 intermediate species of Flaveria plants showed photorespiration activity, which intermediate between that of C3- and C4-flaveria species. These results indicate that in the first land plants, liverworts, photorespiration started to function as electron sink. According to

  18. Two decades of ocean CO2 sink and variability

    International Nuclear Information System (INIS)

    Quere, C. Le; Bopp, L.; Heimann, M.; Prentice, I.C.; Aumont, O.; Bousquet, P.; Ciais, P.; Francey, R.; Rayner, P.J.; Keeling, C.D.; Keeling, R.F.; Piper, S.C.; Kheshgi, H.; Peyliln, P.


    Atmospheric CO 2 has increased at a nearly identical average rate of 3.3 and 3.2 Pg C/yr for the decades of the 1980s and the 1990s, in spite of a large increase in fossil fuel emissions from 5.4 to 6.3 Pg C/yr. Thus, the sum of the ocean and land CO 2 sinks was 1 Pg C/yr larger in the 1990s than in to the 1980s. Here we quantify the ocean and land sinks for these two decades using recent atmospheric inversions and ocean models. The ocean and land sinks are estimated to be, respectively, 0.3 (0.1 to 0.6) and 0.7 (0.4 to 0.9) Pg C/yr larger in the 1990s than in the 1980s. When variability less than 5 yr is removed, all estimates show a global oceanic sink more or less steadily increasing with time, and a large anomaly in the land sink during 1990-1994. For year-to-year variability, all estimates show 1/3 to 1/2 less variability in the ocean than on land, but the amplitude and phase of the oceanic variability remain poorly determined. A mean oceanic sink of 1.9 Pg C/yr for the 1990s based on O 2 observations corrected for ocean outgassing is supported by these estimates, but an uncertainty on the mean value of the order of ±0.7 Pg C/yr remains. The difference between the two decades appears to be more robust than the absolute value of either of the two decades

  19. Pediatric sink-bathing: a risk for scald burns. (United States)

    Baggott, Kaitlin; Rabbitts, Angela; Leahy, Nicole E; Bourke, Patrick; Yurt, Roger W


    Our burn center previously reported a significant incidence of scald burns from tap water among patients treated at the center. However, mechanism of these scalds was not investigated in detail. A recent series of pediatric patients who sustained scalds while bathing in the sink was noted. To evaluate the extent of these injuries and create an effective prevention program for this population, a retrospective study of bathing-related sink burns among pediatric patients was performed. Patients between the ages of 0 and 5.0 years who sustained scald burns while being bathed in the sink were included in this study. Sex, race, age, burn size, length of stay, and surgical procedures were reviewed. During the study period of January 2003 through August 2008, 56 patients who were scalded in the sink were admitted, accounting for 54% of all bathing-related scalds. Among these, 56% were boys and 45% were Hispanic. Mean age was 0.8 ± 0.1 years. Burn size and hospital length of stay averaged 5 ± 0.7% and 11 ± 1 days, respectively. Of this group, 10.7% required skin grafting. The overwhelming majority (94% of patients) were discharged home. The remaining patients were discharged to inpatient rehabilitation, foster care, and others. Pediatric scald burns sustained while bathing in a sink continue to be prevalent at our burn center. Because of limited space and the child's proximity to faucet handles and water flow, sinks are an unsafe location to bathe a child. While such practice may be necessary for some families, comprehensive burn prevention education must address this hazard.

  20. Novel two-phase jet impingement heat sink for active cooling of electronic devices

    International Nuclear Information System (INIS)

    Oliveira, Pablo A. de; Barbosa, Jader R.


    Highlights: • Novel jet-based heat sink integrates the evaporator and the expansion device. • The system was tested with a small-scale oil-free R-134a compressor. • The thermodynamic performance of the cooling system was evaluated experimentally. • The single-jet maximum cooling capacity was 160 W, with a COP of 2.3 and a η 2nd of 8%. • Maximum heat transfer coefficient of 15 kW m −2 K −1 and surface temperature of 30 °C. - Abstract: This work presents a compact vapor compression cooling system equipped with a small-scale oil-free R-134a compressor and a jet-impingement-based heat sink that integrates the evaporator and the expansion device into a single unit. At the present stage of the development, a single orifice was used to generate the high-speed two-phase impinging jet on the heated surface. The effects of the compressor piston stroke, applied thermal load and orifice diameter on the system performance were quantified. The thermodynamic performance of the system was evaluated in terms of the temperature of the heated surface, impinging jet heat transfer coefficient, several system thermal resistances, coefficient of performance, second-law efficiency and second-law ratio. The coefficient of performance of the new refrigeration system increased with the cooling capacity, justifying its application in the removal of large thermal loads. The maximum system cooling capacity with a single jet was approximately 160 W, which was achieved with an orifice diameter of 500 μm and operation at a full compressor piston stroke. This condition corresponded to a COP of 2.3, a second-law efficiency of 8.0%, a jet impingement heat transfer coefficient above 15 kW m −2 K −1 and a heater surface temperature of approximately 30 °C.


    Energy Technology Data Exchange (ETDEWEB)

    Bert Bock; Richard Rhudy; Howard Herzog; Michael Klett; John Davison; Danial G. De La Torre Ugarte; Dale Simbeck


    This project developed life-cycle costs for the major technologies and practices under development for CO{sub 2} storage and sink enhancement. The technologies evaluated included options for storing captured CO{sub 2} in active oil reservoirs, depleted oil and gas reservoirs, deep aquifers, coal beds, and oceans, as well as the enhancement of carbon sequestration in forests and croplands. The capture costs for a nominal 500 MW{sub e} integrated gasification combined cycle plant from an earlier study were combined with the storage costs from this study to allow comparison among capture and storage approaches as well as sink enhancements.

  2. New Method of Sinking Caisson Tunnel in Soft Soil


    Bame, Abda Berisso


    Sinking a caisson tunnel in soft soil is new idea and this new concept could be an alternative method of tunneling in soft soil. The aim of this study is to evaluate geotechnical feasibility of sinking the caisson tunnel to the desired depth at the selected soil profile along tunnel alignment. This caisson tunneling method is proposed to reduce the use of temporary works such as propping of sheet pile walls and increase the ease and speed of construction. Besides, it reduces the disturbance o...

  3. Deficiency of employability capacity

    Directory of Open Access Journals (Sweden)

    Pelse I.


    Full Text Available Young unemployed people have comprised one of the significantly largest groups of the unemployed people in Latvia in recent years. One of the reasons why young people have difficulty integrating into the labour market is the “expectation gap” that exists in the relations between employers and the new generation of workers. Employers focus on capacity-building for employability such individual factors as strength, patience, self-discipline, self-reliance, self-motivation, etc., which having a nature of habit and are developed in a long-term work socialization process, which begins even before the formal education and will continue throughout the life cycle. However, when the socialization is lost, these habits are depreciated faster than they can be restored. Currently a new generation is entering the labour market, which is missing the succession of work socialization. Factors, such as rising unemployment and poverty in the background over the past twenty years in Latvia have created a very unfavourable employability background of “personal circumstances” and “external factors”, which seriously have impaired formation of the skills and attitudes in a real work environment. The study reveals another paradox – the paradox of poverty. Common sense would want to argue that poverty can be overcome by the job. However, the real state of affairs shows that unfavourable coincidence of the individual, personal circumstances and external factors leads to deficit of employability capacity and possibility of marked social and employment deprivation.

  4. Exerting Capacity. (United States)

    Leger, J Michael; Phillips, Carolyn A


    Patient safety has been at the forefront of nursing research since the release of the Institute of Medicine's report estimating the number of preventable adverse events in hospital settings; yet no research to date has incorporated the perspectives of bedside nurses using classical grounded theory (CGT) methodology. This CGT study explored the perceptions of bedside registered nurses regarding patient safety in adult acute care hospitals. Data analysis used three techniques unique to CGT-the constant comparative method, coding, and memoing-to explore the values, realities, and beliefs of bedside nurses about patient safety. The analysis resulted in a substantive theory, Exerting Capacity, which explained how bedside nurses balance the demands of keeping their patients safe. Exerting Capacity has implications for health care organization leaders, nursing leaders, and bedside nurses; it also has indications for future research into the concept of patient safety.

  5. Faster-acting insulin aspart provides faster onset and greater early exposure vs insulin aspart in children and adolescents with type 1 diabetes mellitus. (United States)

    Fath, Maryam; Danne, Thomas; Biester, Torben; Erichsen, Lars; Kordonouri, Olga; Haahr, Hanne


    Faster-acting insulin aspart (faster aspart) is insulin aspart (IAsp) in a new formulation with additional excipients (L-arginine and niacinamide). In adults, faster aspart provides faster onset and greater early exposure and action vs IAsp. This randomized, double-blind, 2-period crossover trial investigated the pharmacological properties of faster aspart vs IAsp in 12 children (6-11 years), 13 adolescents (12-17 years), and 15 adults (18-64 years) with type 1 diabetes mellitus. Subjects received 0.2 U/kg subcutaneous dosing (mean of 8.3, 12.8, and 15.6 U, respectively) immediately prior to a standardized meal (17.3 g carbohydrate/100 mL; amount adjusted by body weight). Consistently across age groups, onset of appearance occurred approximately twice-as-fast (5-7 minutes earlier) and early exposure (AUC IAsp ,0-30min ; area under the IAsp curve from 0 to 30 minutes) was greater (by 78%-147%) for faster aspart vs IAsp, with no treatment differences in total exposure (AUC IAsp ,0-t ) or maximum concentration (C max ). Two-hour postmeal plasma glucose excursion was reduced for faster aspart vs IAsp (although only reaching statistical significance in children). In accordance with the absolute dose administered for each age group, AUC IAsp ,0-t for faster aspart was lower in children (estimated ratio children/adults [95% confidence interval]: 0.59 [0.50;0.69], P IAsp ,0-t and C max did not differ statistically significantly between treatments. Faster aspart and IAsp were well-tolerated. The current findings in children and adolescents suggest a potential for faster aspart to improve postprandial glycemia over current rapid-acting insulins also in younger age groups. identifier: NCT02035371. © 2017 The Authors. Pediatric Diabetes published by John Wiley & Sons Ltd.

  6. Sink strength simulations using the Monte Carlo method: Applied to spherical traps (United States)

    Ahlgren, T.; Bukonte, L.


    The sink strength is an important parameter for the mean-field rate equations to simulate temporal changes in the micro-structure of materials. However, there are noteworthy discrepancies between sink strengths obtained by the Monte Carlo and analytical methods. In this study, we show the reasons for these differences. We present the equations to estimate the statistical error for sink strength calculations and show the way to determine the sink strengths for multiple traps. We develop a novel, very fast Monte Carlo method to obtain sink strengths. The results show that, in addition to the well-known sink strength dependence of the trap concentration, trap radius and the total sink strength, the sink strength also depends on the defect diffusion jump length and the total trap volume fraction. Taking these factors into account, allows us to obtain a very accurate analytic expression for the sink strength of spherical traps.

  7. Source-sink relationships in two soybean cultivars with indeterminate growth under water deficit

    Directory of Open Access Journals (Sweden)

    Alexandre José da Silva

    Full Text Available Abstract Water deficit is a major factor limiting crop yield in rainfed areas. We hypothesized that under water deficit the decrease of photosynthetic production stimulates: carbohydrate remobilization from leaves, stems and roots to reproductive organs; and decreasing flowering intensity and pod development. The present work aims to study the effect of water deficit during bloom and grain pod-filling stages in two indeterminate soybean cultivar, Vtop and Nidera. The following physiological parameters were evaluated by means of daily CO2 assimilation rate (Ai, dynamic of carbohydrates in tissues, plant growth, grain yield and yield components. The study was conducted in a greenhouse with plants sown in tanks of 0.5 m3. Regardless of the phenological phase, water deficit reduced Ai, plant growth and number of pods and seeds per plant. The fact that grain yield was less affected by water deficit at bloom than at grain pod-filling stage was attributed to larger seeds found at bloom. In both treatments, a sharp reduction on carbohydrate content was found in leaves, stem and roots at the beginning of pod formation. The high amounts of carbohydrates remobilized for seed growth, along with the high values of Ai observed in well-watered plants, indicate that grain yield of soybeans is source rather than sink limited. On the other hand, in water deficit treatments, a new stimulus for carbohydrate storage was found in the leaves and stem at the beginning of grain maturity, suggesting that grain yield was limited by sink capacity.

  8. Factoring out natural and indirect human effects on terrestrial carbon sources and sinks

    International Nuclear Information System (INIS)

    Canadell, J.G.; Kirschbaum, M.U.F.; Kurz, W.A.; Sanz, M.J.; Schlamadinger, B.; Yamagata, Y.


    The capacity to partition natural, indirect, and direct human-induced effects on terrestrial carbon (C) sources and sinks is necessary to be able to predict future terrestrial C dynamics and thus their influence on atmospheric CO2 growth. However, it will take a number of years before we can better attribute quantitative estimates of the contribution of various C processes to the net C balance. In a policy context, factoring out natural and indirect human-induced effects on C sources and sinks from the direct human-induced influences, is seen as a requirement of a C accounting approach that establishes a clear and unambiguous connection between human activities and the assignment of C credits and debits. We present options for factoring out various groups of influences including climate variability, CO2 and N fertilization, and legacies from forest management. These are: (1) selecting longer accounting or measurement periods to reduce the effects of inter-annual variability; (2) correction of national inventories for inter-annual variability; (3) use of activity-based accounting and C response curves; (4) use of baseline scenarios or benchmarks at the national level; (5) stratification of the landscape into units with distinct average C stocks. Other, more sophisticated modeling approaches (e.g., demographic models in combination with forest inventories; process-based models) are possible options for future C accounting systems but their complexity and data requirements make their present adoption more difficult in an inclusive international C accounting system

  9. Westerly Winds and the Southern Ocean CO2 Sink Since the Last Glacial-Interglacial Transition (United States)

    Hodgson, D. A.; Saunders, K. M.; Roberts, S. J.; Perren, B.; Butz, C.; Sime, L. C.; Davies, S. J.; Grosjean, M.


    The capacity of the Southern Ocean carbon sink is partly controlled by the Southern Hemisphere westerly winds (SHW) and sea ice. These regulate the upwelling of dissolved carbon-rich deep water to Antarctic surface waters, determine the surface area for air-sea gas exchange and therefore modulate the net uptake of atmospheric CO2. Some models have proposed that strengthened SHW will result in a weakening of the Southern Ocean CO2 sink. If these models are correct, then one would expect that reconstructions of changes in SHW intensity on centennial to millennial timescales would show clear links with Antarctic ice core and Southern Ocean marine geological records of atmospheric CO2, temperature and sea ice. Here, we present a 12,300 year reconstruction of past wind strength based on three independent proxies that track the changing inputs of sea salt aerosols and minerogenic particles into lake sediments on sub-Antarctic Macquarie Island. The proxies are consistent in showing that periods of high wind intensity corresponded with the increase in CO2 across the late Last Glacial-Interglacial Transition and in the last 7,000 years, suggesting that the winds have contributed to the long term outgassing of CO2 from the ocean during these periods.

  10. Quantifying greenhouse gas sources and sinks in managed wetland systems (United States)

    Stephen M Ogle; Patrick Hunt; Carl Trettin


    This chapter provides methodologies and guidance for reporting greenhouse gas (GHG) emissions and sinks at the entity scale for managed wetland systems. More specifically, it focuses on methods for managed palustrine wetlands.1 Section 4.1 provides an overview of wetland systems and resulting GHG emissions, system boundaries and temporal scale, a summary of the...

  11. An unusual presentation of Burkitt's lymphoma | Sinke | Malawi ...

    African Journals Online (AJOL)

    An unusual presentation of Burkitt's lymphoma. EA Sinke, EJ van Hasselt. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More ...

  12. Minimization of sink mark defects in injection molding process ...

    African Journals Online (AJOL)

    Handling of numerous processing variables to control defects is a mammoth task that costs time, effort and money. This paper presents a simple and efficient way to study the influence of injection molding variables on sink marks using Taguchi approach. Using the Taguchi approach, optimal parameter settings and the ...

  13. Enhanced heat sink with geometry induced wall-jet

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, Md. Mahamudul, E-mail:; Tikadar, Amitav; Bari, Fazlul; Morshed, A. K. M. M. [Department of Mechanical Engineering Bangladesh University of Engineering and Technology, Dhaka-1000. Bangladesh (Bangladesh)


    Mini-channels embedded in solid matrix have already proven to be a very efficient way of electronic cooling. Traditional mini-channel heat sinks consist of single layer of parallel channels. Although mini-channel heat sink can achieve very high heat flux, its pumping requirement for circulating liquid through the channel increase very sharply as the flow velocity increases. The pumping requirements of the heat sink can be reduced by increasing its performance. In this paper a novel approach to increase the thermal performance of the mini-channel heat sink is proposed through geometry induced wall jet which is a passive technique. Geometric irregularities along the channel length causes abrupt pressure change between the channels which causes cross flow through the interconnections thus one channel faces suction and other channel jet action. This suction and jet action disrupts boundary layer causing enhanced heat transfer performance. A CFD model has been developed using commercially available software package FLUENT to evaluate the technique. A parametric study of the velocities and the effect of the position of the wall-jets have been performed. Significant reduction in thermal resistance has been observed for wall-jets, it is also observed that this reduction in thermal resistance is dependent on the position and shape of the wall jet.

  14. A new method to optimize natural convection heat sinks (United States)

    Lampio, K.; Karvinen, R.


    The performance of a heat sink cooled by natural convection is strongly affected by its geometry, because buoyancy creates flow. Our model utilizes analytical results of forced flow and convection, and only conduction in a solid, i.e., the base plate and fins, is solved numerically. Sufficient accuracy for calculating maximum temperatures in practical applications is proved by comparing the results of our model with some simple analytical and computational fluid dynamics (CFD) solutions. An essential advantage of our model is that it cuts down on calculation CPU time by many orders of magnitude compared with CFD. The shorter calculation time makes our model well suited for multi-objective optimization, which is the best choice for improving heat sink geometry, because many geometrical parameters with opposite effects influence the thermal behavior. In multi-objective optimization, optimal locations of components and optimal dimensions of the fin array can be found by simultaneously minimizing the heat sink maximum temperature, size, and mass. This paper presents the principles of the particle swarm optimization (PSO) algorithm and applies it as a basis for optimizing existing heat sinks.

  15. Cleaning up nitrogen pollution may reduce future carbon sinks

    NARCIS (Netherlands)

    Gu, Baojing; Ju, Xiaotang; Wu, Yiyun; Erisman, Jan Willem; Bleeker, Albert; Reis, Stefan; Sutton, Mark A.; Lam, Shu Kee; Smith, Pete; Oenema, Oene; Smith, Rognvald I.; Lu, Xuehe; Ye, Xinyue; Chen, Deli


    Biosphere carbon sinks are crucial for reducing atmospheric carbon dioxide (CO2) concentration to mitigate global warming, but are substantially affected by the input of reactive nitrogen (Nr). Although the effects of anthropogenic CO2 emission and nitrogen deposition (indicated by Nr emission to

  16. Million Trees Los Angeles: Carbon dioxide sink or source? (United States)

    E.G. McPherson; A. Kendall; S. Albers


    This study seeks to answer the question, 'Will the Million Trees LA (MTLA) programme be a CO2 sink or source?' Using surveys, interviews, field sampling and computer simulation of tree growth and survival over a 40-year period, we developed the first process-based life cycle inventory of CO2 for a large tree...

  17. Development of an operations evaluation system for sinking EDM

    NARCIS (Netherlands)

    Lauwers, B.; Oosterling, J.A.J.; Vanderauwera, W.


    This paper describes the development and validation of an operations evaluation system for sinking EDM operations. Based on a given workpiece geometry (e.g. mould), regions to be EDM'ed are automatically indentified. For a given electrode configuration, consisting of one or more regions, EDM

  18. Children's Typically-Perceived-Situations of Floating and Sinking (United States)

    Joung, Yong Jae


    The purpose of this study is to explore children's typically-perceived-situations (TPS) of "floating" and "sinking". TPS refers to the situation rising spontaneously in an individual's mind when they first think of a phenomenon or concept. Data were collected from 148 Year 5 Korean children. As a result of analysing the data…

  19. Role of Sink Density in Nonequilibrium Chemical Redistribution in Alloys (United States)

    Martínez, Enrique; Senninger, Oriane; Caro, Alfredo; Soisson, Frédéric; Nastar, Maylise; Uberuaga, Blas P.


    Nonequilibrium chemical redistribution in open systems submitted to external forces, such as particle irradiation, leads to changes in the structural properties of the material, potentially driving the system to failure. Such redistribution is controlled by the complex interplay between the production of point defects, atomic transport rates, and the sink character of the microstructure. In this work, we analyze this interplay by means of a kinetic Monte Carlo (KMC) framework with an underlying atomistic model for the Fe-Cr model alloy to study the effect of ideal defect sinks on Cr concentration profiles, with a particular focus on the role of interface density. We observe that the amount of segregation decreases linearly with decreasing interface spacing. Within the framework of the thermodynamics of irreversible processes, a general analytical model is derived and assessed against the KMC simulations to elucidate the structure-property relationship of this system. Interestingly, in the kinetic regime where elimination of point defects at sinks is dominant over bulk recombination, the solute segregation does not directly depend on the dose rate but only on the density of sinks. This model provides new insight into the design of microstructures that mitigate chemical redistribution and improve radiation tolerance.

  20. Predator transitory spillover induces trophic cascades in ecological sinks

    DEFF Research Database (Denmark)

    Casini, Michele; Blenckner, Thorsten; Möllmann, Christian


    Understanding the effects of cross-system fluxes is fundamental in ecosystem ecology and biological conservation. Source-sink dynamics and spillover processes may link adjacent ecosystems by movement of organisms across system boundaries. However, effects of temporal variability in these cross...

  1. Characterization of Hop-and-Sink Locomotion of Water Fleas (United States)

    Skipper, A. N.; Murphy, D. W.; Webster, D. R.


    The freshwater crustacean Daphnia magna is a widely studied zooplankton in relation to food webs, predator-prey interactions, and other biological/ecological considerations; however, their locomotion is poorly quantified and understood. These water fleas utilize a hop-and-sink mechanism that consists of making quick, impulsive jumps by beating their antennae to propel themselves forward (roughly 1 body length). The animals then sink for a period, during which they stretch out their antennae to increase drag and thereby reduce their sinking velocity. Time-resolved three-dimensional flow fields surrounding the animals were quantified with a unique infrared tomographic particle image velocimetry (tomo-PIV) system. Three-dimensional kinematics data were also extracted from the image sequences. In the current work, we compared body kinematics and flow disturbance among organisms of size in the range of 1.3 to 2.8 mm. The stroke cycle averaged 150 +/- 20 ms, with each stroke cycle split nearly evenly between power and recovery strokes. The kinematics data collapsed onto a self-similar curve when properly nondimensionalized, and a general trend was shown to exist between the nondimensionalized peak body speed and body length. The fluid flow induced by each antennae consisted of a viscous vortex ring that demonstrated a slow decay in the wake. The viscous dissipation showed no clear dependence on body size, whereas the volume of fluid exceeding 5 mm/s (the speed near the sinking speed of the animal) decayed more slowly with increasing body size.

  2. Source to sink transport and regulation by environmental factors

    Directory of Open Access Journals (Sweden)

    Remi eLemoine


    Full Text Available Source-to-sink transport of sugar is one of the major determinants of plant growth and relies on the efficient and controlled distribution of sucrose (and some other sugars such as raffinose and polyols across plant organs through the phloem. However, sugar transport through the phloem can be affected by many environmental factors that alter source/sink relationships. In this paper, we summarize current knowledge about the phloem transport mechanisms and review the effects of several abiotic (water and salt stress, mineral deficiency, CO2, light, temperature, air and soil pollutants and biotic (mutualistic and pathogenic microbes, viruses, aphids and parasitic plants factors. Concerning abiotic constraints, alteration of the distribution of sugar among sinks is often reported, with some sinks as roots favoured in case of mineral deficiency. Many of these constraints impair the transport function of the phloem but the exact mechanisms are far from being completely known. Phloem integrity can be disrupted (e.g. by callose deposition and under certain conditions, phloem transport is affected, earlier than photosynthesis. Photosynthesis inhibition could result from the increase in sugar concentration due to phloem transport decrease. Biotic interactions (aphids, fungi, viruses… also affect crop plant productivity. Recent breakthroughs have identified some of the sugar transporters involved in these interactions on the host and pathogen sides. The different data are discussed in relation to the phloem transport pathways. When possible, the link with current knowledge on the pathways at the molecular level will be highlighted.


    The sink strength of two common indoor materials, a carpet and a gypsum board, was evaluated by environmental chamber tests with four volatile organic compounds (VOCs): propylene glycol, ethylene glycol, 2-(2-butoxyethoxy)ethanol (BEE), and texanol. These oxygenated compounds rep...

  4. Source and Sink Strength of Carbon Dioxide, Methane and ...

    African Journals Online (AJOL)


    Full-text Available Online at Source and Sink Strength of Carbon Dioxide, Methane and Distribution of Sulfate in Salt-marsh Soils at the Wadden Sea Coast of Northern Germany. ·1KHAN, MD. HARUNOR RASHID; 2HANS-PETER BLUME; 1TADASHI. ADACHI; 3ULRICH PFISTERER; 3UDO MÜLLER- ...

  5. Pathway of phloem unloading in tobacco sink leaves

    International Nuclear Information System (INIS)

    Turgeon, R.


    Phloem unloading in transition sink leaves of tobacco (Nicotiana tabacum L.) was analyzed by quantitative autoradiography. Source leaves were labeled with 14 CO 2 and experimental treatments were begun approximately 1 h later when label had entered the sink leaves. Autoradiographs were prepared from rapidly frozen, lyophilized sink tissue at the beginning and end of the treatments and the amount of label in veins and in surrounding cells was determined by microdensitometry. Photoassimilate unloaded from third order and larger, but not smaller, veins. Long-distance import and unloading did not respond the same way to all experimental treatments. Import was completely inhibited by cold, anaerobiosis or steam girdling the sink leaf petiole. Unloading was inhibited by cold but continued in an anaerobic atmosphere and after steam girdling. Uptake of exogenous [ 14 C]sucrose was inhibited by anaerobiosis. Since an apoplastic pathway of phloem unloading would involve solute uptake from the apoplast the results are most consistent with passive symplastic unloading of photoassimilates from phloem to surrounding cells

  6. Minimization of sink mark defects in injection molding process ...

    African Journals Online (AJOL)


    Arriving at critical variables based on initial screening. 5. Additional expanded Taguchi's experiments for minimization of sink marks. 2.1. Design of simple, scalable and generic model and machine selection: A simple and scalable disc part (Figure 1) was prepared using Pro/Engineer. The model base wall was fixed at 3mm.

  7. Analysis of ultimate-heat-sink spray ponds. Technical report

    International Nuclear Information System (INIS)

    Codell, R.


    This report develops models which can be utilized in the design of certain types of spray ponds used in ultimate heat sinks at nuclear power plants, and ways in which the models may be employed to determine the design basis required by U.S. Nuclear Regulatory Commission Regulatory Guide 1.27

  8. Sink or Swim? Debt Review's Ambivalent "Lifeline" ____A Second ...

    African Journals Online (AJOL)

    Full title: Sink or Swim? Debt Review's Ambivalent "Lifeline" ---- A Second Sequel To "… A Tale of Two Judgments" Nedbank V Andrews (240/2011) 2011 Zaecpehc 29 (10 May 2011); Firstrand Bank Ltd V Evans 2011 4 SA 597 (KZD) And Firstrand Bank Ltd V Janse Van Rensburg 2012 2 All SA 186 (ECP). The interface ...

  9. Capacity Building

    International Nuclear Information System (INIS)

    Molloy, Brian; Mallick, Shahid


    Outcomes & Recommendations: • Significant increase needed in the nuclear workforce both to replace soon-to-retire current generation and to staff large numbers of new units planned • Key message, was the importance of an integrated approach to workforce development. • IAEA and other International Organisations were asked to continue to work on Knowledge Management, Networks and E&T activities • IAEA requested to conduct Global Survey of HR needs – survey initiated but only 50% of operating countries (30% of capacity) took part, so results inconclusive

  10. Capacity and Capacity Utilization in Fishing Industries


    Kirkley, James E; Squires, Dale


    Excess capacity of fishing fleets is one of the most pressing problems facing the world's fisheries and the sustainable harvesting of resource stocks. Considerable confusion persists over the definition and measurement of capacity and capacity utilization in fishing. Fishing capacity and capacity utilization, rather than capital (or effort) utilization, provide the appropriate framework. This paper provides both technological-economic and economic definitions of capacity and excess capacity i...

  11. Leaky Sinks: Should (Paleo)erosion Rates and Floodplain Sedimentation Rates Covary? (United States)

    Willenbring, J. K.; Brocard, G. Y.


    Sediments in floodplain are the only available terrestrial record of past environmental conditions in some settings. The information gleaned from these floodplain sediments - specifically rates of sedimentation - are often used as indirect indicators of past erosion rates. Ultimately, erosion and the deposition rates must match to satisfy mass balance. However, over short-timescales storage creates unsteadiness in this balance, and over long-timescales floodplains act as `leaky sinks.' A global compilation of Holocene floodplain accumulation rates suggests rates measured over the last 100 years are faster than those averaged over 1000 years, which in turn are faster than those for the last 10000 years. The apparent acceleration in sedimentation rates appears globally synchronous, despite diachronous human and land use histories and can pre-date significant human land use. The pattern of rate increase in sedimentation over time (inverse power law) and rates of erosion that match over short and long timescales point to the rate increase indicating infilling behavior of all floodplains and not specifically tied to the supply of (anthropogenic) sediment. The apparent synchrony of accelerating floodplain accumulation is consistent with a model that could include but does not require increased anthropogenic erosion or more, recent flooding episodes. In this presentation, we will present our progress and prospects of developing a new technique to quantify paleoerosion rates in floodplain sediments along the Rio Fajardo in eastern Puerto Rico. We use meteoric cosmogenic 10Be concentrations to observe changed in erosion rate at multiple radiocarbon-dated intervals. Due to sea level rise providing accommodation space, this floodplain sedimentation record spans the last 20,000 years. During this time, sedimentation rates and potentially El Nino hurricane-forced erosion have fluctuated in concert with meteoric 10Be concentrations. This work was supported by the U.S. National

  12. Available transmission capacity assessment

    Directory of Open Access Journals (Sweden)

    Škokljev Ivan


    Full Text Available Effective power system operation requires the analysis of vast amounts of information. Power market activities expose power transmission networks to high-level power transactions that threaten normal, secure operation of the power system. When there are service requests for a specific sink/source pair in a transmission system, the transmission system operator (TSO must allocate the available transfer capacity (ATC. It is common that ATC has a single numerical value. Additionally, the ATC must be calculated for the base case configuration of the system, while generation dispatch and topology remain unchanged during the calculation. Posting ATC on the internet should benefit prospective users by aiding them in formulating their requests. However, a single numerical value of ATC offers little for prospect for analysis, planning, what-if combinations, etc. A symbolic approach to the power flow problem (DC power flow and ATC offers a numerical computation at the very end, whilst the calculation beforehand is performed by using symbols for the general topology of the electrical network. Qualitative analysis of the ATC using only qualitative values, such as increase, decrease or no change, offers some new insights into ATC evaluation, multiple transactions evaluation, value of counter-flows and their impact etc. Symbolic analysis in this paper is performed after the execution of the linear, symbolic DC power flow. As control variables, the mathematical model comprises linear security constraints, ATC, PTDFs and transactions. The aim is to perform an ATC sensitivity study on a five nodes/seven lines transmission network, used for zonal market activities tests. A relatively complicated environment with twenty possible bilateral transactions is observed.

  13. Hybrid embryos of Vicia faba develop enhanced sink strength, which is established during early development. (United States)

    Meitzel, Tobias; Radchuk, Ruslana; Nunes-Nesi, Adriano; Fernie, Alisdair R; Link, Wolfgang; Weschke, Winfriede; Weber, Hans


    Selfed and crossed seeds of two homozygous Vicia faba lines served as models for the analysis of the physiological and molecular mechanisms underlying embryo heterosis. Profiles of transcripts, metabolites and seed contents of developing embryos were analysed to compare the means of reciprocally crossed and selfed seeds growing on the same mother plants. The mean weight of mature hybrid seeds was demonstrably higher, revealing mid-parent heterosis. Hybrid embryos exhibited a prolonged early phase of development and delayed onset of storage activity. Accordingly, transcript profiling indicates stimulation of cell proliferation, an effect, which is potentially mediated by activation of auxin functions within a framework of growth-related transcription factors. At the transcript level, activated cell proliferation increased assimilate uptake activity and thereby seed sink strength. This situation might finally lead to the increased size of the hybrid seeds. We conclude that hybrid seeds are characterised by accelerated growth during early development, which increases storage capacity and leads to higher metabolic fluxes. These needs are, at least partially, met by increased assimilate uptake capacity. The stimulated growth of hybrid seeds shifted metabolite profiles and potentially depleted available pools. Such metabolic shifts are most likely secondary effects resulting from the higher storage capacity of hybrid seeds, a heterotic feature, which is itself established very early in seed development. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

  14. Sink stimulation of leaf photosynthesis by the carbon costs of rhizobial and arbuscular mycorrhizal fungal symbioses

    NARCIS (Netherlands)

    Kaschuk, G.


    Key words: biochemical model of leaf photosynthesis; carbon sink strength; chlorophyll fluorescence; harvest index; leaf protein; leaf senescence; legumes; photosynthetic nutrient use efficiency; Pi recycling; source-sink regulation; ureides One of the most fascinating processes in plant

  15. Lifetime Optimization of a Multiple Sink Wireless Sensor Network through Energy Balancing

    Directory of Open Access Journals (Sweden)

    Tapan Kumar Jain


    Full Text Available The wireless sensor network consists of small limited energy sensors which are connected to one or more sinks. The maximum energy consumption takes place in communicating the data from the nodes to the sink. Multiple sink WSN has an edge over the single sink WSN where very less energy is utilized in sending the data to the sink, as the number of hops is reduced. If the energy consumed by a node is balanced between the other nodes, the lifetime of the network is considerably increased. The network lifetime optimization is achieved by restructuring the network by modifying the neighbor nodes of a sink. Only those nodes are connected to a sink which makes the total energy of the sink less than the threshold. This energy balancing through network restructuring optimizes the network lifetime. This paper depicts this fact through simulations done in MATLAB.

  16. Analysis on the Role of RSG-GAS Pool Cooling System during Partial Loss of Heat Sink Accident (United States)

    Susyadi; Endiah, P. H.; Sukmanto, D.; Andi, S. E.; Syaiful, B.; Hendro, T.; Geni, R. S.


    RSG-GAS is a 30 MW reactor that is mostly used for radioisotope production and experimental activities. Recently, it is regularly operated at half of its capacity for efficiency reason. During an accident, especially loss of heat sink, the role of its pool cooling system is very important to dump decay heat. An analysis using single failure approach and partial modeling of RELAP5 performed by S. Dibyo, 2010 shows that there is no significant increase in the coolant temperature if this system is properly functioned. However lessons learned from the Fukushima accident revealed that an accident can happen due to multiple failures. Considering ageing of the reactor, in this research the role of pool cooling system is to be investigated for a partial loss of heat sink accident which is at the same time the protection system fails to scram the reactor when being operated at 15 MW. The purpose is to clarify the transient characteristics and the final state of the coolant temperature. The method used is by simulating the system in RELAP5 code. Calculation results shows the pool cooling systems reduce coolant temperature for about 1 K as compared without activating them. The result alsoreveals that when the reactor is being operated at half of its rated power, it is still in safe condition for a partial loss of heat sink accident without scram.

  17. Acoustic monitoring of a ball sinking in vibrated granular sediments (United States)

    van den Wildenberg, Siet; Léopoldès, Julien; Tourin, Arnaud; Jia, Xiaoping


    We develop an ultrasound probing to investigate the dynamics of a high density ball sinking in 3D opaque dense granular suspensions under horizontal weak vibrations. We show that the motion of the ball in these horizontally vibrated glass bead packings saturated by water is consistent with the frictional rheology. The extracted stress-strain relation evidences an evolution of flow behaviour from frictional creep to inertial regimes. Our main finding is that weak external vibration primarily affects the yield stress and controls the depth of sinking via vibration-induced sliding at the grain contact. Also, we observe that the extracted rheological parameters depend on the size of the probing ball, suggesting thus a non-local rheology.

  18. Finite element simulation of sink pass round tubes using Ansys

    Directory of Open Access Journals (Sweden)

    Nagarkar M.P.


    Full Text Available Modeling and simulation of metal forming processes are increasingly in demand from the industry as the resulting models are found to be valuable tools considering the optimization of the existing and development of new processes. By the application of modeling and simulation techniques, it is possible to reduce the number of time-consuming experiments such as prototyping. Seamless tubes of various sizes and shapes are manufactured by various processes like sinking, fixed plug, floating plug, moving mandrel, cold working and hot working. The present work deals with the simulation of round tubes while passing through the sink pass, using ANSYS software. The simulation results are the displacement and von Mises stresses. The procedure can be used to improve the product quality and to study the effect of various parameters like die angle on the product quality.

  19. Carbon Sinks in a Changing Climate: Relative Buoyancy and Sinking Potentials of Various Antarctic Phytoplankton and Ice Algae (United States)

    Nirmel, S.; Selz, V.


    Polar phytoplankton play instrumental roles in global biogeochemical cycles, sometimes serving as massive carbon sinks via the biological pump. In addition to phytoplankton, sea ice supports a significant amount of ice algae, the essential primary producers for the ecosystem in winter and early spring. While sea ice habitat declines on regional scales, the fate of sea ice algae post-ice melt remains relatively unknown, despite its importance in understanding how the biological pump might be affected by sea ice loss. Through a series of settling column experiments on the icebreaker Nathaniel B. Palmer, we aimed to address the question: What controls the fate of the carbon-rich ice algae across the Western Antarctic Peninsula (WAP) during ice melt? We focused on whether species composition affects the sinking potential of ice algal communities. Using FlowCAM imagery, we classified samples collected from the buoyant, neutral, and negatively buoyant portions of the settling columns into genus-level taxonomic classes. We used image parameters and geometric shape equations to calculate the biovolume of each taxonomic group. We further explored relationships between taxa-specific sinking potentials, environmental parameters (temperature and nutrients), and physiological properties of associated algal communities (as described by Fast Rate Repetition fluorometry). Results indicate that colonial Phaeocystis antarctica tends to dominate lower regions of the settling column. Moreover, we observe strong correlations between geographic location and both nutrients and phytoplankton physiology. We found that these three factors are indeed related to taxa-specific buoyancy and sinking indices. An understanding of these relationships sheds more light on the role P. antarctica (a carbon-rich bloom-forming genus) plays in the biological pump; higher sinking rates suggest greater carbon export to depth, while lower sinking rates increase the likelihood of carbon being respired back

  20. Modeling Atmospheric CO2 Processes to Constrain the Missing Sink (United States)

    Kawa, S. R.; Denning, A. S.; Erickson, D. J.; Collatz, J. C.; Pawson, S.


    We report on a NASA supported modeling effort to reduce uncertainty in carbon cycle processes that create the so-called missing sink of atmospheric CO2. Our overall objective is to improve characterization of CO2 source/sink processes globally with improved formulations for atmospheric transport, terrestrial uptake and release, biomass and fossil fuel burning, and observational data analysis. The motivation for this study follows from the perspective that progress in determining CO2 sources and sinks beyond the current state of the art will rely on utilization of more extensive and intensive CO2 and related observations including those from satellite remote sensing. The major components of this effort are: 1) Continued development of the chemistry and transport model using analyzed meteorological fields from the Goddard Global Modeling and Assimilation Office, with comparison to real time data in both forward and inverse modes; 2) An advanced biosphere model, constrained by remote sensing data, coupled to the global transport model to produce distributions of CO2 fluxes and concentrations that are consistent with actual meteorological variability; 3) Improved remote sensing estimates for biomass burning emission fluxes to better characterize interannual variability in the atmospheric CO2 budget and to better constrain the land use change source; 4) Evaluating the impact of temporally resolved fossil fuel emission distributions on atmospheric CO2 gradients and variability. 5) Testing the impact of existing and planned remote sensing data sources (e.g., AIRS, MODIS, OCO) on inference of CO2 sources and sinks, and use the model to help establish measurement requirements for future remote sensing instruments. The results will help to prepare for the use of OCO and other satellite data in a multi-disciplinary carbon data assimilation system for analysis and prediction of carbon cycle changes and carbodclimate interactions.

  1. Sinking failure of scour protection at wind turbine foundation

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Nielsen, Anders W.


    This paper summarises the results of an experimental study on scour protection around offshore wind turbine foundations, with special emphasis on the sinking failure of the scour protection work in Horns Rev 1 offshore wind farm (Denmark). The paper reviews previous results obtained by the author....... A brief account is also given of filter criteria and their application to the Horns Rev 1 case, whereby the present results and the filter criteria results are linked....

  2. Analytical analysis and experimental verification of interleaved parallelogram heat sink

    International Nuclear Information System (INIS)

    Chen, Hong-Long; Wang, Chi-Chuan


    Highlights: • A novel air-cooled heat sink profile (IPFM) is proposed to compete with the typical design. • It features two different perimeters with odd fin being rectangular and the rest being parallelogram. • A new modified dimensionless parameter characterized the flow length in triangular region is proposed. • The analytical predictions are in line with the experiments for both conventional and IPFM design. • IPFM design shows a much lower pressure drop and a superior performance especially for dense fins. - Abstract: In this study, a novel air-cooled heat sink profile is proposed to compete with the conventional design. The new design is termed as IPFM (Interleaved Parallelogram Fin Module) which features two different geometrical perimeter shapes of fins. This new design not only gains the advantage of lower pressure drop for power saving; but also gains a material saving for less fin surface area. An assessment of flow impedance and performance between the conventional and IPFM heat sink is analytically investigated and experimentally verified. A new modified dimensionless friction factor for triangular region is proposed. The analytical predictions agree with experimental measurements for both conventional and IPFM design. In electronic cooling design, especially for cloud server air-cooled heat sink design, the flow pattern is usually laminar with Reynolds number being operated less than 2000. In this regime, the IPFM design shows 8–12% less of surface than conventional design when the flow rate is less than 10 CFM; yet the thermal performance is slightly inferior to the conventional design when the flowrate is raised towards 25 CFM. Yet in the test range of 5–25 CFM, a 10–15% lower flow impedance is observed. The smaller fin spacing, the more conspicuous reduction of flow impedance is observed. The optimization of cutting angle is around 35° for 10 CFM, and it is reduced to 15° at a larger flowrate of 20 CFM.

  3. Pin fin compliant heat sink with enhanced flexibility

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Mark D.


    Heat sinks and methods of using the same include a top and bottom plate, at least one of which has a plurality of pin contacts flexibly connected to one another, where the plurality of pin contacts have vertical and lateral flexibility with respect to one another; and pin slice layers, each having multiple pin slices, arranged vertically between the top and bottom plates such that the plurality of pin slices form substantially vertical pins connecting the top and bottom plates.

  4. Sinking of armour layer around a vertical cylinder exposed to waves and current

    DEFF Research Database (Denmark)

    Nielsen, Anders Wedel; Probst, Thomas; Petersen, Thor Ugelvig


    The mechanisms of the sinking of a scour protection adjacent to a monopile are described in this paper, together with the determination of the equilibrium sinking depth in various wave and combined wave and current conditions based on physical model tests.Sinking of the rocks may ultimately lead ...

  5. Reconstruction and attribution of the carbon sink of European forests between 1950 and 2000

    NARCIS (Netherlands)

    Bellassen, V.; Viovy, N.; Luyssaert, S.; Maire, G.; Schelhaas, M.; Ciais, P.


    European forests are an important carbon sink; however, the relative contributions to this sink of climate, atmospheric CO2 concentration ([CO2]), nitrogen deposition and forest management are under debate. We attributed the European carbon sink in forests using ORCHIDEE-FM, a process-based

  6. Reconstruction and attribution of the carbon sink of European forests between 1950 and 2000

    NARCIS (Netherlands)

    Bellassen, Valentin; Viovy, Nicolas; Luyssaert, Sebastiaan; Le Maire, Guerric; Schelhaas, Mart Jan; Ciais, Philippe


    European forests are an important carbon sink; however, the relative contributions to this sink of climate, atmospheric CO 2 concentration ([CO 2]), nitrogen deposition and forest management are under debate. We attributed the European carbon sink in forests using ORCHIDEE-FM, a process-based

  7. The sinking of the Soviet Mike class nuclear powered submarine

    International Nuclear Information System (INIS)


    The purpose of this preliminary study is to assess the quantities of the longer-lived or persistent radioactive materials, or source terms, that have been lost at sea with the sinking of the Soviet MIKE class submarine off Bear Island on 7 April 1989. The report arrives at an assessment of the amount of radioactivity and compares this to the quantities of radioactive materials dumped by the UK from 1953 to 1982 at which time sea dumping of radioactive wastes was suspended by international resolve. This comparison can be used to assess the relative significance of the sinking of this submarine. The study does not extrapolate the estimated radioactive source terms to an environmental or radiological significance of the sinking, although it is concluded that unless the submarine is recovered intact from the ocean floor, the by far greater part of the radioactive materials on board will disperse to the marine environment at some future time, if they are not doing so already. (author)

  8. Control of Delta Avulsion by Downstream Sediment Sinks (United States)

    Salter, Gerard; Paola, Chris; Voller, Vaughan R.


    Understanding how fluxes are partitioned at delta bifurcations is critical for predicting patterns of land loss and gain in deltas worldwide. Although the dynamics of river deltas are influenced from both upstream and downstream, previous studies of bifurcations have focused on upstream controls. Using a quasi-1-D bifurcation model, we show that flow switching in bifurcations is strongly influenced by downstream sediment sinks. We find that coupling between upstream and downstream feedbacks can lead to oscillations in water and sediment flux partitioning. The frequency and initial rate of growth/decay of the oscillations depend on both upstream and downstream conditions, with dimensionless bifurcate length and bypass fraction emerging as key downstream parameters. With a strong offshore sink, causing bypass in the bifurcate branches, we find that bifurcation dynamics become "frozen"; that is, the bifurcation settles on a permanent discharge ratio. In contrast, under depositional conditions, we identify three dynamical regimes: symmetric; soft avulsion, where both branches remain open but the dominant branch switches; and full avulsion. Finally, we show that differential subsidence alters these regimes, with the difference in average sediment supply to each branch exactly compensating for the difference in accommodation generation. Additionally, the model predicts that bifurcations with shorter branches are less asymmetric than bifurcations with longer branches, all else equal, providing a possible explanation for the difference between backwater length distributaries, which tend to be avulsive, and relatively stable mouth-bar-scale networks. We conclude that bifurcations are sensitive both quantitatively and qualitatively to downstream sinks.

  9. [Carbon storage and carbon sink of mangrove wetland: research progress]. (United States)

    Zhang, Li; Guo, Zhi-hua; Li, Zhi-yong


    Mangrove forest is a special wetland forest growing in the inter-tidal zone of tropical and subtropical regions, playing important roles in windbreak, promoting silt sedimentation, resisting extreme events such as cyclones and tsunamis, and protecting coastline, etc. The total area of global mangrove forests is about 152000 km2, only accounting for 0. 4% of all forest area. There are about 230 km2 mangrove forests in China. The mangrove forests in the tropics have an average carbon storage as high as 1023 Mg hm-2, and the global mangrove forests can sequestrate about 0. 18-0. 228 Pg C a-1. In addition to plant species composition, a variety of factors such as air temperature, seawater temperature and salinity, soil physical and chemical properties, atmospheric CO2 concentration, and human activities have significant effects on the carbon storage and sink ability of mangrove forests. Many approaches based onfield measurements, including allometric equations, remote sensing, and model simulation, are applied to quantify the carbon storage and sink ability of mangrove forest wetland. To study the carbon storage and sink ability of mangrove wetland can promote the further understanding of the carbon cycle of mangrove wetland and related controlling mechanisms, being of significance for the protection and rational utilization of mangrove wetland.

  10. Boreal forest BVOC exchange: emissions versus in-canopy sinks (United States)

    Zhou, Putian; Ganzeveld, Laurens; Taipale, Ditte; Rannik, Üllar; Rantala, Pekka; Petteri Rissanen, Matti; Chen, Dean; Boy, Michael


    A multilayer gas dry deposition model has been developed and implemented into a one-dimensional chemical transport model SOSAA (model to Simulate the concentrations of Organic vapours, Sulphuric Acid and Aerosols) to calculate the dry deposition velocities for all the gas species included in the chemistry scheme. The new model was used to analyse in-canopy sources and sinks, including gas emissions, chemical production and loss, dry deposition, and turbulent transport of 12 featured biogenic volatile organic compounds (BVOCs) or groups of BVOCs (e.g. monoterpenes, isoprene+2-methyl-3-buten-2-ol (MBO), sesquiterpenes, and oxidation products of mono- and sesquiterpenes) in July 2010 at the boreal forest site SMEAR II (Station for Measuring Ecosystem-Atmosphere Relations). According to the significance of modelled monthly-averaged individual source and sink terms inside the canopy, the selected BVOCs were classified into five categories: 1. Most of emitted gases are transported out of the canopy (monoterpenes, isoprene + MBO). 2. Chemical reactions remove a significant portion of emitted gases (sesquiterpenes). 3. Bidirectional fluxes occur since both emission and dry deposition are crucial for the in-canopy concentration tendency (acetaldehyde, methanol, acetone, formaldehyde). 4. Gases removed by deposition inside the canopy are compensated for by the gases transported from above the canopy (acetol, pinic acid, β-caryophyllene's oxidation product BCSOZOH). 5. The chemical production is comparable to the sink by deposition (isoprene's oxidation products ISOP34OOH and ISOP34NO3). Most of the simulated sources and sinks were located above about 0.2 hc (canopy height) for oxidation products and above about 0.4 hc for emitted species except formaldehyde. In addition, soil deposition (including deposition onto understorey vegetation) contributed 11-61 % to the overall in-canopy deposition. The emission sources peaked at about 0.8-0.9 hc, which was higher than 0.6 hc

  11. Performance evaluation of faster R-CNN on GPU for object detection

    African Journals Online (AJOL)


    Sep 10, 2017 ... using deep ConvNet to categorize object proposals. After that, spatial pyramid pooling networks .... overview of Faster R-CNN with RPN. Fig.5.Left: Overview of faster R-CNN network. ..... In 3rd International Conference on Learning Representations, 2015, pp. 1-14. [16] Fadhlan H K Z, Md. Hazrat A, Amir A S ...

  12. Evaluating Thermoelectric Power Generation Device Performance Using a Rectangular Microchannel Heat Sink

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Rosendahl, Lasse


    In this work, a microchannel heat sink is applied to a thermoelectric power generation (TEG) device and compared with a traditional heat sink. The advantages and disadvantages of using each heat sink in a TEG device are evaluated. The microchannel hydraulic diameter is 5.33 x 10-4 m and that of t......In this work, a microchannel heat sink is applied to a thermoelectric power generation (TEG) device and compared with a traditional heat sink. The advantages and disadvantages of using each heat sink in a TEG device are evaluated. The microchannel hydraulic diameter is 5.33 x 10-4 m...... and thermal parameters are considered for both laminar and turbulent regimes in the channels. Furthermore, using the temperature difference through each TEG, the system efficiency is calculated. The results show that the microchannel heat sink gives a higher pressure drop, but the heat flow across the TEG...

  13. The effect of glyphosate on import into a sink leaf of sugar beet

    International Nuclear Information System (INIS)

    Shieh, Wenjang; Geiger, D.R.


    The basis for glyphosate inducted limitation of carbon import into developing leaves was studied in sugar beet. To separate the effects of the herbicide on export from those on import, glyphosate was supplied to a developing leaf from two exporting source leaves which fed the sink leaf. Carbon import into the sink leaf was determined by supplying 14 CO 2 to a third source leaf which also supplies carbon to the monitored sink leaf. Import into the sink leaf decreased within 2 to 3 h after glyphosate application, even though photosynthesis and export in the source leaf supplying 14 C were unaffected. Reduced import into the sink leaf was accompanied by increased import by the tap root. Elongation of the sink leaf was only slightly decreased following arrival of glyphosate. Photosynthesis by the sink leaf was not inhibited. The results to data support the view that import is slowed by the inhibition of synthesis of structural or storage compounds in the developing leaves

  14. Over-expression of AtPAP2 in Camelina sativa leads to faster plant growth and higher seed yield

    Directory of Open Access Journals (Sweden)

    Zhang Youjun


    Full Text Available Abstract Background Lipids extracted from seeds of Camelina sativa have been successfully used as a reliable source of aviation biofuels. This biofuel is environmentally friendly because the drought resistance, frost tolerance and low fertilizer requirement of Camelina sativa allow it to grow on marginal lands. Improving the species growth and seed yield by genetic engineering is therefore a target for the biofuels industry. In Arabidopsis, overexpression of purple acid phosphatase 2 encoded by Arabidopsis (AtPAP2 promotes plant growth by modulating carbon metabolism. Overexpression lines bolt earlier and produce 50% more seeds per plant than wild type. In this study, we explored the effects of overexpressing AtPAP2 in Camelina sativa. Results Under controlled environmental conditions, overexpression of AtPAP2 in Camelina sativa resulted in longer hypocotyls, earlier flowering, faster growth rate, higher photosynthetic rate and stomatal conductance, increased seed yield and seed size in comparison with the wild-type line and null-lines. Similar to transgenic Arabidopsis, activity of sucrose phosphate synthase in leaves of transgenic Camelina was also significantly up-regulated. Sucrose produced in photosynthetic tissues supplies the building blocks for cellulose, starch and lipids for growth and fuel for anabolic metabolism. Changes in carbon flow and sink/source activities in transgenic lines may affect floral, architectural, and reproductive traits of plants. Conclusions Lipids extracted from the seeds of Camelina sativa have been used as a major constituent of aviation biofuels. The improved growth rate and seed yield of transgenic Camelina under controlled environmental conditions have the potential to boost oil yield on an area basis in field conditions and thus make Camelina-based biofuels more environmentally friendly and economically attractive.

  15. Capacity Expansion and Reliability Evaluation on the Networks Flows with Continuous Stochastic Functional Capacity

    Directory of Open Access Journals (Sweden)

    F. Hamzezadeh


    Full Text Available In many systems such as computer network, fuel distribution, and transportation system, it is necessary to change the capacity of some arcs in order to increase maximum flow value from source s to sink t, while the capacity change incurs minimum cost. In real-time networks, some factors cause loss of arc’s flow. For example, in some flow distribution systems, evaporation, erosion or sediment in pipes waste the flow. Here we define a real capacity, or the so-called functional capacity, which is the operational capacity of an arc. In other words, the functional capacity of an arc equals the possible maximum flow that may pass through the arc. Increasing the functional arcs capacities incurs some cost. There is a certain resource available to cover the costs. First, we construct a mathematical model to minimize the total cost of expanding the functional capacities to the required levels. Then, we consider the loss of flow on each arc as a stochastic variable and compute the system reliability.

  16. Assessing Canada's Forest Carbon Sinks from 1901 TO 2008 BY Combining Inventory with Climate Data (Invited) (United States)

    Chen, J. M.; Wu, C.; Gonsamo, A.; Kurz, W.; Hember, R.; Price, D. T.; Boisvenue, C.; Zhang, F.; Chang, K.


    The forest carbon cycle is not only controlled by climate, tree species and site conditions, but also by disturbance affecting the biomass and age of forest stands. The Carbon Budget Model of the Canadian forest sector (CBM-CFS3) calculates the complete forest carbon cycle by combining forest inventory data on forest species, biomass and stand age with empirical yield information and statistics on forest disturbances, management and land-use change. It is used for national reporting and climate policy purposes. The Integrated Terrestrial Ecosystem Carbon model (InTEC) is driven by remotely-sensed vegetation parameters (forest type, leaf area index, clumping index) and fire scar, soil and climate data and simulates forest growth and the carbon cycle as a function of stand age using a process-based approach. Gridded forest biomass, stand age and disturbance data based on forest inventory are also used as inputs to InTEC. Efforts are being made to enhance the CBM-CFS3's capacity to assess the impacts of global change on the forest carbon budget by utilizing InTEC process modeling methodology. For this purpose, InTEC is first implemented on 3432 permanent sampling plots in coastal and interior BC, and it is found that climate warming explained 70% and 75% of forest growth enhancement over the period from 1956 to 2001 in coastal and interior BC, respectively, and the remainder is attributed to CO2 and nitrogen fertilization effects. The growth enhancement, in terms of the increase in the stemwood accumulation rate after adjusting for the stand age effect, is about 24% for both areas over the same period. To assess the impact of climate change on the forest carbon cycle across Canada, polygon-based CBM and gridded InTEC results are aggregated to 60 reconciliation units (RU), and their interannual variabilities over the period from 1990 to 2008 are compared in each RU. CBM results show interannual variability in response to forest disturbance, while InTEC results show

  17. Bacterial Succession on Sinking Particles in the Ocean's Interior

    Directory of Open Access Journals (Sweden)

    Erik A. Pelve


    Full Text Available Sinking particles formed in the photic zone and moving vertically through the water column are a main mechanism for nutrient transport to the deep ocean, and a key component of the biological carbon pump. The particles appear to be processed by a microbial community substantially different from the surrounding waters. Single cell genomics and metagenomics were employed to describe the succession of dominant bacterial groups during particle processing. Sinking particles were extracted from sediment traps at Station Aloha in the North Pacific Subtropical Gyre (NPSG during two different trap deployments conducted in July and August 2012. The microbial communities in poisoned vs. live sediment traps differed significantly from one another, consistent with prior observations by Fontanez et al. (2015. Partial genomes from these communities were sequenced from cells belonging to the genus Arcobacter (commensalists potentially associated with protists such as Radiolaria, and Vibrio campbellii (a group previously reported to be associated with crustacea. These bacteria were found in the particle-associated communities at specific depths in both trap deployments, presumably due to their specific host-associations. Partial genomes were also sequenced from cells belonging to Idiomarina and Kangiella that were enriched in live traps over a broad depth range, that represented a motile copiotroph and a putatively non-motile algicidal saprophyte, respectively. Planktonic bacterial cells most likely caught in the wake of the particles belonging to Actinomarina and the SAR11 clade were also sequenced. Our results suggest that similar groups of eukaryote-associated bacteria are consistently found on sinking particles at different times, and that particle remineralization involves specific, reproducible bacterial succession events in oligotrophic ocean waters.

  18. Subterranean karst environments as a global sink for atmospheric methane (United States)

    Webster, Kevin D.; Drobniak, Agnieszka; Etiope, Giuseppe; Mastalerz, Maria; Sauer, Peter E.; Schimmelmann, Arndt


    The air in subterranean karst cavities is often depleted in methane (CH4) relative to the atmosphere. Karst is considered a potential sink for the atmospheric greenhouse gas CH4 because its subsurface drainage networks and solution-enlarged fractures facilitate atmospheric exchange. Karst landscapes cover about 14% of earth's continental surface, but observations of CH4 concentrations in cave air are limited to localized studies in Gibraltar, Spain, Indiana (USA), Vietnam, Australia, and by incomplete isotopic data. To test if karst is acting as a global CH4 sink, we measured the CH4 concentrations, δ13CCH4, and δ2HCH4 values of cave air from 33 caves in the USA and three caves in New Zealand. We also measured CO2 concentrations, δ13CCO2, and radon (Rn) concentrations to support CH4 data interpretation by assessing cave air residence times and mixing processes. Among these caves, 35 exhibited subatmospheric CH4 concentrations in at least one location compared to their local atmospheric backgrounds. CH4 concentrations, δ13CCH4, and δ2HCH4 values suggest that microbial methanotrophy within caves is the primary CH4 consumption mechanism. Only 5 locations from 3 caves showed elevated CH4 concentrations compared to the atmospheric background and could be ascribed to local CH4 sources from sewage and outgassing swamp water. Several associated δ13CCH4 and δ2HCH4 values point to carbonate reduction and acetate fermentation as biochemical pathways of limited methanogenesis in karst environments and suggest that these pathways occur in the environment over large spatial scales. Our data show that karst environments function as a global CH4 sink.

  19. Salt Marshes as Sources and Sinks of Silica (United States)

    Carey, J.; Fulweiler, R. W.


    The role of salt marshes in controlling silica exchange between terrestrial and marine environments is unclear. In some studies, large quantities of dissolved silica (DSi) appear to be exported from marshes via tidal exchange, potentially fueling future diatom production in adjacent waters. In contrast, other studies report insignificant DSi export and found instead that salt marshes appeared to be Si sinks. Further, few studies examine salt marsh Si export in relation to inorganic nitrogen (DIN) and phosphorus (DIP). We address these uncertainties by quantifying net fluxes of DSi and biogenic Si (BSi), as well as DIN and DIP during the spring and summer in a relatively undisturbed southern New England salt marsh (Narragansett Bay, USA). Our data demonstrates that during the spring, when estuarine waters are deplete in DSi, the marsh serves as a net sink of BSi (132 mol h-1) and a source of DSi (31 mol h-1) to the estuary. The spring DIN:DSi ratios of ebbing water were more than five times lower than flood waters. Most importantly, the DSi export rates (6.5 x103 mol d-1 km-2) are an order of magnitude larger than the export by rivers in the region (115 mol d-1 km-2), indicating the marsh tidal exchange is vital in supplying the Si necessary for spring diatom blooms in the estuary. Conversely, during the summer the marsh served as a net Si sink, importing on average 59 mol DSi h-1 and 39 mol BSi h-1. These data highlight that the role of salt marshes in silica cycling appears to have a strong seasonality. We hypothesize that net import of Si increases the residence time of Si in estuarine systems, providing an important and previously over-looked ecosystem service. In the absence of salt marshes, ~5.1 x 104 kmol of Si would be exported from this system during the growing season, possibly decreasing Si availability and altering phytoplankton species composition in the estuary.

  20. Sources and Sinks: Elucidating Mechanisms, Documenting Patterns, and Forecasting Impacts (United States)


    Walker, L. E., Marzluff, J. M., & Cimprich, D. A. 2016. Source-sink population dynamics driven by a brood parasite : A case study of an endangered songbird, the black- capped vireo. Biological Conservation 203:108-118. ...relied on resighting banded birds . However, even with over 600 banded birds and >300 natal dispersal records, we did not have enough resightings among...less than 10 g in mass, making long term tracking via telemetry difficult due to the weight restrictions on protected migratory birds . Despite

  1. Fate and transport of fragrance materials in principal environmental sinks. (United States)

    Zhang, Xiaolei; Brar, Satinder Kaur; Yan, Song; Tyagi, Rajeshwar Dayal; Surampalli, Rao Y


    Fragrance materials are widely present in the environment, such as air, water, and soil. Concerns have been raised due to the increasing utilization and suspected impact on human health. The bioaccumulating property is considered as one of the causes of the toxicity to human beings. The removal of fragrance materials from environmental sinks has not been paid enough attention due to the lack of regulation and research on their toxicity. This paper provides systematic information on how fragrance materials are transferred to the environment, how do they affect human lives, and what is their fate in water, wastewater, wastewater sludge, and soil. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Recent findings on sinks for sulfide in gravity sewer networks

    DEFF Research Database (Denmark)

    Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes


    Sulfide buildup in sewer networks is associated with several problems, including health impacts, corrosion of sewer structures and odor nuisance. In recent years, significant advances in the knowledge of the major processes governing sulfide buildup in sewer networks have been made. This paper...... summarizes this newly obtained knowledge and emphasizes important implications of the findings. Model simulations of the in-sewer processes important for the sulfur cycle showed that sulfide oxidation in the wetted biofilm is typically the most important sink for dissolved sulfide in gravity sewers. However...

  3. Is The Bovine Pedal Bone Sinking Around Calving?

    DEFF Research Database (Denmark)

    Bach, Kurt; Nielsen, Søren Saxmose; Capion, Nynne

    Introduction Softening of connective tissue of the claw suspensory apparatus around calving as described by Tarlton, et al. (2002) may lead to sinking of the bovine pedal bone resulting in compression of the digital cushion. The objective of this study was to describe changes in the thickness...... covered with water to improve the image quality. At each examination, the body condition score (BCS) of the heifers was recorded. The thickness of the soft tissue in the sole, defined as the distance between inner margin of the sole horn and the pedal bone, was measured on the ultrasonographic images...

  4. Optimizing single irrigation scheme to improve water use efficiency by manipulating winter wheat sink-source relationships in Northern China Plain. (United States)

    Xu, Xuexin; Zhang, Yinghua; Li, Jinpeng; Zhang, Meng; Zhou, Xiaonan; Zhou, Shunli; Wang, Zhimin


    Improving winter wheat grain yield and water use efficiency (WUE) with minimum irrigation is very important for ensuring agricultural and ecological sustainability in the Northern China Plain (NCP). A three-year field experiment was conducted to determine how single irrigation can improve grain yield and WUE by manipulating the "sink-source" relationships. To achieve this, no-irrigation after sowing (W0) as a control, and five single irrigation treatments after sowing (75 mm of each irrigation) were established. They included irrigation at upstanding (WU), irrigation at jointing (WJ), irrigation at booting (WB), irrigation at anthesis (WA) and irrigation at medium milk (WM). Results showed that compared with no-irrigation after sowing (W0), WU, WJ, WB, WA and WM significantly improved mean grain yield by 14.1%, 19.9%, 17.9%, 11.6%, and 7.5%, respectively. WJ achieved the highest grain yield (8653.1 kg ha-1) and WUE (20.3 kg ha-1 mm-1), and WB observed the same level of grain yield and WUE as WJ. In comparison to WU, WJ and WB coordinated pre- and post-anthesis water use while reducing pre-anthesis and total evapotranspiration (ET). They also retained higher soil water content above 180 cm soil layers at anthesis, increased post-anthesis water use, and ultimately increased WUE. WJ and WB optimized population quantity and individual leaf size, delayed leaf senescence, extended grain-filling duration, improved post-anthesis biomass and biomass remobilization (source supply capacity) as well as post-anthesis biomass per unit anthesis leaf area (PostBA-leaf ratio). WJ also optimized the allocation of assimilation, increased the spike partitioning index (SPI, spike biomass/biomass at anthesis) and grain production efficiency (GPE, the ratio of grain number to biomass at anthesis), thus improved mean sink capacity by 28.1%, 5.7%, 21.9%, and 26.7% in comparison to W0, WU, WA and WM, respectively. Compared with WA and WM, WJ and WB also increased sink capacity, post

  5. CO2 Sink/Source in the Indonesian Seas

    KAUST Repository

    Kartadikaria, Aditya R.


    Two distinct CO2 sink/source characteristics appeared from the compiled observed data 1984-2013 in the tropical Indonesian seas. The western part persistently emits CO2 to the atmosphere, while the eastern is rather dynamic which emits and absorbs smaller amount of CO2 to and from atmosphere, respectively. The segregation is proximal to the virtual Wallace line, where in the continental shelf is located. Lower salinity and higher silicate condition in the western part influenced the higher pCO2 condition in Java Sea. Temperature is found to have a limited influence to control different characteristic in the west and east, but SST change of 2.0 0C during La Ninã condition effectively reduced the source amount of CO2 by 50% compared to Normal year condition. Yet, during La Ninã, higher wind speed increases CO2 flux twice compared to Normal year. In the continental shelf area where CO2 sink area is found, 29 years data showed that pCO2 trend is increasing ±0.6-3.8 μatm/year. From this study, the overall areas have a significant source of CO2 of approximately 10 - 24 μatm.

  6. Thermal performance measurements on ultimate heat sinks--cooling ponds

    International Nuclear Information System (INIS)

    Hadlock, R.K.; Abbey, O.B.


    The primary objective of the studies described is to obtain the requisite data, with respect to modeling requirements, to characterize thermal performance of heat sinks for nuclear facilities existing at elevated water temperatures in result of experiencing a genuinely large heat load and responding to meteorological influence. The data should reflect thermal performance for combinations leading to worst-case meteorological influence. A geothermal water retention basin has been chosen as the site for the first measurement program and data have been obtained in the first of several experiments scheduled to be performed there. These data illustrate the thermal and water budgets during episodes of cooling from an initially high pond water bulk temperature. Monitoring proceeded while the pond experienced only meteorological and seepage influence. The data are discussed and are presented as a data volume which may be used for calculation purposes. Suggestions for future measurement programs are stated with the intent to maintain and improve relevance to nuclear ultimate heat sinks while continuing to examine the performance of the analog geothermal pond. It is further suggested that the geothermal pond, with some modification, may be a suitable site for spray pond measurements

  7. A highly stable microchannel heat sink for convective boiling

    International Nuclear Information System (INIS)

    Lu, Chun Ting; Pan Chin


    To develop a highly stable two-phase microchannel heat sink, we experimented with convective boiling in diverging, parallel microchannels with different distributions of laser-etched artificial nucleation sites. Each microchannel had a mean hydraulic diameter of 120 µm. The two-phase flow visualization and the magnitudes of pressure drop and inlet temperature oscillations under boiling conditions demonstrated clearly the merits of using artificial nucleation sites to further stabilize the flow boiling in diverging, parallel microchannels. The stability map showed the plane of subcooling number versus phase change number. It illustrated that diverging, parallel microchannels with artificial nucleation cavities have a much wider stable region than parallel microchannels with uniform cross-sections or diverging, parallel microchannels without artificial nucleation cavities. In addition, the results revealed that the design with cavities distributed uniformly along the downstream half of the channel presented the best stability performance among the three distributions of nucleation sites. This particular design can be regarded as a highly stable microchannel heat sink for convective boiling

  8. Plant Fructokinases: Evolutionary, Developmental, and Metabolic Aspects in Sink Tissues

    Directory of Open Access Journals (Sweden)

    Ofer Stein


    Full Text Available Sucrose, a glucose–fructose disaccharide, is the main sugar transported in the phloem of most plants and is the origin of most of the organic matter. Upon arrival in sink tissues, the sucrose must be cleaved by invertase or sucrose synthase. Both sucrose-cleaving enzymes yield free fructose, which must be phosphorylated by either fructokinase (FRK or hexokinase (HXK. The affinity of FRK to fructose is much higher than that of HXK, making FRKs central for fructose metabolism. An FRK gene family seems to exist in most, if not all plants and usually consists of several cytosolic FRKs and a single plastidic FRK. These genes are expressed mainly in sink tissues such as roots, stems, flowers, fruits, and seeds, with lower levels of expression often seen in leaves. Plant FRK enzymes vary in their biochemical properties such as affinity for fructose, inhibition by their substrate (i.e., fructose, and expression level in different tissues. This review describes recently revealed roles of plant FRKs in plant development, including the combined roles of the plastidic and cytosolic FRKs in vascular tissues and seed development.

  9. My car is sinking: automobile submersion, lessons in vehicle escape. (United States)

    Giesbrecht, Gordon G; McDonald, Gerren K


    In North America approximately 400 individuals per year die in submersed vehicles, accounting for 5-11% of all drownings. About half of people surveyed would let the vehicle fill with water before attempting exit. We used a crane and two passenger vehicles of the same make, model, and year-one with passenger compartment intact (I) and one with holes (H) in the floor (area approximately 2200 cm2)--to conduct occupied and unoccupied submersions. Three phases of submersion were identified: 1) FLOATING, vehicles floated for 15 s (H) to 63 s (I) before the water reached the bottom of the side windows; 2) SINKING, the subsequent period until the vehicle is completely under water, but before it fills completely; and 3) SUBMERGED, the vehicle was full of water and several feet below the surface. Total time to submersion was 150 s for I but only 37 s for H. Opening the door to exit Vehicle I decreased submersion time from 150 to 30 s. Even the most difficult exit strategy attempted (three men and a child manikin through one window) was quickly performed from Vehicle I (only 51 s). During one exit attempt, initiated during the sinking phase, it was impossible to open the doors or windows until the vehicle was completely full of water. A vehicle is most easily exited during the initial Floating Phase. We suggest the following escape procedure: SEATBELT(s) unfastened; WINDOWS open; CHILDREN released from restraints and brought close to an adult; and OUT, children should exit first.

  10. Modeling the dynamical sinking of biogenic particles in oceanic flow

    Directory of Open Access Journals (Sweden)

    P. Monroy


    Full Text Available We study the problem of sinking particles in a realistic oceanic flow, with major energetic structures in the mesoscale, focussing on the range of particle sizes and densities appropriate for marine biogenic particles. Our aim is to evaluate the relevance of theoretical results of finite size particle dynamics in their applications in the oceanographic context. By using a simplified equation of motion of small particles in a mesoscale simulation of the oceanic velocity field, we estimate the influence of physical processes such as the Coriolis force and the inertia of the particles, and we conclude that they represent negligible corrections to the most important terms, which are passive motion with the velocity of the flow, and a constant added vertical velocity due to gravity. Even if within this approximation three-dimensional clustering of particles can not occur, two-dimensional cuts or projections of the evolving three-dimensional density can display inhomogeneities similar to the ones observed in sinking ocean particles.

  11. A neural network-based estimate of the seasonal to inter-annual variability of the Atlantic Ocean carbon sink (United States)

    Landschützer, P.; Gruber, N.; Bakker, D. C. E.; Schuster, U.; Nakaoka, S.; Payne, M. R.; Sasse, T.; Zeng, J.


    The Atlantic Ocean is one of the most important sinks for atmospheric carbon dioxide (CO2), but this sink is known to vary substantially in time. Here we use surface ocean CO2 observations to estimate this sink and the temporal variability from 1998 to 2007 in the Atlantic Ocean. We benefit from (i) a continuous improvement of the observations, i.e., the Surface Ocean CO2 Atlas (SOCAT) v1.5 database and (ii) a newly developed technique to interpolate the observations in space and time. In particular, we use a 2 step neural network approach to reconstruct basin-wide monthly maps of the sea surface partial pressure of CO2 (pCO2) at a resolution of 1° × 1°. From those, we compute the air-sea CO2 flux maps using a standard gas exchange parameterization and high-resolution wind speeds. The neural networks fit the observed pCO2 data with a root mean square error (RMSE) of about 10 μatm and with almost no bias. A check against independent time series data reveals a larger RMSE of about 17 μatm. We estimate a decadal mean uptake flux of -0.45 ± 0.15 Pg C yr-1 for the Atlantic between 44° S and 79° N, representing the sum of a strong uptake north of 18° N (-0.39 ± 0.10 Pg C yr-1), outgassing in the tropics (18° S-18° N, 0.11 ± 0.07 Pg C yr-1), and uptake in the subtropical/temperate South Atlantic south of 18° S (-0.16 ± 0.06 Pg C yr-1), consistent with recent studies. We find the strongest seasonal variability of the CO2 flux in the temperature driven subtropical North Atlantic, with uptake in winter and outgassing in summer. The seasonal cycle is antiphased in the subpolar latitudes relative to the subtropics largely as a result of the biologically driven winter-to-summer drawdown of CO2. Over the analysis period (1998 to 2007) sea surface pCO2 increased faster than that of the atmosphere in large areas poleward of 40° N, but many other parts of the North Atlantic increased more slowly, resulting in a barely changing Atlantic carbon sink north of the

  12. Identifying the Right Disease Targets to Develop Better Drugs, Faster | NIH MedlinePlus the Magazine (United States)

    ... this page please turn JavaScript on. Identifying the Right Disease Targets to Develop Better Drugs, Faster Past ... reason is that we're not selecting the right biological changes to target from the start. How ...

  13. An energy efficient multiple mobile sinks based routing algorithm for wireless sensor networks (United States)

    Zhong, Peijun; Ruan, Feng


    With the fast development of wireless sensor networks (WSNs), more and more energy efficient routing algorithms have been proposed. However, one of the research challenges is how to alleviate the hot spot problem since nodes close to static sink (or base station) tend to die earlier than other sensors. The introduction of mobile sink node can effectively alleviate this problem since sink node can move along certain trajectories, causing hot spot nodes more evenly distributed. In this paper, we mainly study the energy efficient routing method with multiple mobile sinks support. We divide the whole network into several clusters and study the influence of mobile sink number on network lifetime. Simulation results show that the best network performance appears when mobile sink number is about 3 under our simulation environment.

  14. New Configurations of Micro Plate-Fin Heat Sink to Reduce Coolant Pumping Power (United States)

    Rezania, A.; Rosendahl, L. A.


    The thermal resistance of heat exchangers has a strong influence on the electric power produced by a thermoelectric generator (TEG). In this work, a real TEG device is applied to three configurations of micro plate-fin heat sink. The distance between certain microchannels is varied to find the optimum heat sink configuration. The particular focus of this study is to reduce the coolant mass flow rate by considering the thermal resistances of the heat sinks and, thereby, to reduce the coolant pumping power in the system. The three-dimensional governing equations for the fluid flow and the heat transfer are solved using the finite-volume method for a wide range of pressure drop laminar flows along the heat sink. The temperature and the mass flow rate distribution in the heat sink are discussed. The results, which are in good agreement with previous computational studies, show that using suggested heat sink configurations reduces the coolant pumping power in the system.

  15. LPTA: Location Predictive and Time Adaptive Data Gathering Scheme with Mobile Sink for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Chuan Zhu


    Full Text Available This paper exploits sink mobility to prolong the lifetime of sensor networks while maintaining the data transmission delay relatively low. A location predictive and time adaptive data gathering scheme is proposed. In this paper, we introduce a sink location prediction principle based on loose time synchronization and deduce the time-location formulas of the mobile sink. According to local clocks and the time-location formulas of the mobile sink, nodes in the network are able to calculate the current location of the mobile sink accurately and route data packets timely toward the mobile sink by multihop relay. Considering that data packets generating from different areas may be different greatly, an adaptive dwelling time adjustment method is also proposed to balance energy consumption among nodes in the network. Simulation results show that our data gathering scheme enables data routing with less data transmission time delay and balance energy consumption among nodes.

  16. Effects of low sink demand on leaf photosynthesis under potassium deficiency. (United States)

    Pan, Yonghui; Lu, Zhifeng; Lu, Jianwei; Li, Xiaokun; Cong, Rihuan; Ren, Tao


    The interaction between low sink demand and potassium (K) deficiency in leaf photosynthesis was not intensively investigated, therefore this interaction was investigated in winter oilseed rape (Brassica napus L.). Plants subjected to sufficient (+K) or insufficient (-K) K supply treatments were maintained or removed their flowers and pods; these conditions were defined as high sink demand (HS) or low sink demand (LS), respectively. The low sink demand induced a lower photosynthetic rate (P n ), especially in the -K treatment during the first week. A negative relationship between P n and carbohydrate concentration was observed in the -K treatment but not in the +K treatment, suggesting that the decrease in P n in the -K treatment was the result of sink feedback regulation under low sink demand. Longer sink removal duration increased carbohydrate concentration, but the enhanced assimilate did not influence P n . On the contrary, low sink demand resulted in a high K concentration, slower chloroplast degradation rate and better PSII activity, inducing a higher P n compared with HS. Consequently, low sink demand decreased leaf photosynthesis over the short term due to sink feedback regulation, and potassium deficiency enhanced the photosynthetic decrease through carbohydrate accumulation and a lower carbohydrate concentration threshold for initiating photosynthesis depression. A longer duration of limited sink demand and sufficient potassium supply resulted in a higher photosynthesis rate because of delayed chloroplast degradation. This finding indicates that the nutritional status plays a role in leaf photosynthesis variations due to sink-source manipulation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. Radiation Effects in Dual Heat Sinks for Cooling of Concentrated Photovoltaics (United States)


    IN DUAL HEAT SINKS FOR COOLING OF CONCENTRATED PHOTOVOLTAICS by Mark T. Brandau June 2016 Thesis Advisor: Garth Hobson Co-Advisor...thesis 4. TITLE AND SUBTITLE RADIATION EFFECTS IN DUAL HEAT SINKS FOR COOLING OF CONCENTRATED PHOTOVOLTAICS 5. FUNDING NUMBERS 6. AUTHOR(S) Mark...examined the effectiveness of improving the cooling of concentrated photovoltaics (CPV) through the use of dual heat sinks. The intent was to improve

  18. Nested atmospheric inversion for the terrestrial carbon sources and sinks in China

    Directory of Open Access Journals (Sweden)

    F. Jiang


    Full Text Available In this study, we establish a nested atmospheric inversion system with a focus on China using the Bayesian method. The global surface is separated into 43 regions based on the 22 TransCom large regions, with 13 small regions in China. Monthly CO2 concentrations from 130 GlobalView sites and 3 additional China sites are used in this system. The core component of this system is an atmospheric transport matrix, which is created using the TM5 model with a horizontal resolution of 3° × 2°. The net carbon fluxes over the 43 global land and ocean regions are inverted for the period from 2002 to 2008. The inverted global terrestrial carbon sinks mainly occur in boreal Asia, South and Southeast Asia, eastern America and southern South America. Most China areas appear to be carbon sinks, with strongest carbon sinks located in Northeast China. From 2002 to 2008, the global terrestrial carbon sink has an increasing trend, with the lowest carbon sink in 2002. The inter-annual variation (IAV of the land sinks shows remarkable correlation with the El Niño Southern Oscillation (ENSO. The terrestrial carbon sinks in China also show an increasing trend. However, the IAV in China is not the same as that of the globe. There is relatively stronger land sink in 2002, lowest sink in 2006, and strongest sink in 2007 in China. This IAV could be reasonably explained with the IAVs of temperature and precipitation in China. The mean global and China terrestrial carbon sinks over the period 2002–2008 are −3.20 ± 0.63 and −0.28 ± 0.18 PgC yr−1, respectively. Considering the carbon emissions in the form of reactive biogenic volatile organic compounds (BVOCs and from the import of wood and food, we further estimate that China's land sink is about −0.31 PgC yr−1.

  19. New Configurations of Micro Plate-Fin Heat Sink to Reduce Coolant Pumping Power

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Rosendahl, Lasse


    The thermal resistance of heat exchangers has a strong influence on the electric power produced by a thermoelectric generator (TEG). In this work, a real TEG device is applied to three configurations of micro plate-fin heat sink. The distance between certain microchannels is varied to find...... the optimum heat sink configuration. The particular focus of this study is to reduce the coolant mass flow rate by considering the thermal resistances of the heat sinks and, thereby, to reduce the coolant pumping power in the system. The threedimensional governing equations for the fluid flow and the heat...... heat sink configurations reduces the coolant pumping power in the system....

  20. Impingement thermal performance of perforated circular pin-fin heat sinks (United States)

    Wen, Mao-Yu; Yeh, Cheng-Hsiung


    The study presents the experimental information on heat transfer performance of jet impingement cooling on circular pin- fin heat sinks with/without a hollow perforated base plate. Smoke flow visualization is also used to investigate the behavior of the complicated flow phenomena of the present heat sinks for this impingement cooling. The effects of flow Reynolds numbers (3458≤Re≤11,526), fin height, the geometry of the heat sinks (with/without a hollow perforated base plate), and jet-to-test heat sink placement (1 ≤ H/ d≤16) are examined. In addition, empirical correlation to estimate the heat transfer coefficient was also developed.

  1. The 'Jupiter' sinking: effects on children's fears, depression and anxiety. (United States)

    Yule, W; Udwin, O; Murdoch, K


    Twenty-five girls who survived the sinking of the cruise ship 'Jupiter' were compared with three other groups of girls--71 controls from a separate school; 46 girls in the same school who had not wanted to go on the cruise; and 13 girls who were in a 'near miss' group in that they wanted to go but did not get places. All completed the Fear Survey Schedule for Children (revised form), the Children's Manifest Anxiety Scale and the Birleson Depression Inventory. Survivors did not become generally more fearful. Rather, they developed significantly greater fears to stimuli related to the traumatic event. The results are discussed in relation to the conditioning theory of the acquisition of phobias.

  2. What Really Caused the ROKS Cheonan Warship Sinking?

    Directory of Open Access Journals (Sweden)

    Hwang Su Kim


    Full Text Available This paper is concerned with the sinking of the Korean naval warship (ROKS Cheonan and the reported spectra of the seismic signals recorded at the time of the incident. The spectra of seismic signals show prominently amplitude peaks at around 8.5 Hz and its harmonics. These frequencies were explained with the vibrations of a water column due to an underwater explosion. This explanation is highly doubtful and concerns about its validity have already been raised in the scientific community. In this work an alternative explanation is presented: it is shown that the recorded seismic spectra are consistent with the natural frequencies of vibrations of a large submarine with a length of around 113 m. This finding raises the possibility that the ROKS Cheonan sunk because of the collision with a large submarine rather than the explosion of a torpedo or an underwater mine.

  3. Important aspects of sinks for linking emission trading systems

    Energy Technology Data Exchange (ETDEWEB)

    Hirsbrunner, Simon; Taenzler, Dennis; Reuster, Lena [Adelphi Research gGmbH, Berlin (Germany)


    The discussion on how to design policy instruments to reduce emissions and enhance removals from land use, land use change, and forestry is likely to be a key feature of a future global climate protection framework and will also influence the design of an emerging global carbon market. By analyzing different ETSs it turns out that very specific provisions are in place to deal with carbon sinks. Different instruments, eligible activities and standards reflect the prevailing emissions profile and cultural preferences of a geographic area. The inclusion of forestry in a cap, for instance, makes provisions on additionality and non-permanence obsolete, but increases the relevance of other issues such as accounting and enforcement. (orig.)

  4. Sinking into the Sea? Climate Change and AOSIS Strategies

    DEFF Research Database (Denmark)

    Højland, Camille Marie Risager; Svendsen, Gert Tinggaard


    Agreement, 2) A CO2 tax, 3) Subsidising new green technology, 4) That AOSIS should look for coalition partners, e.g. China, and 5) Even stronger focus on the linkage between climate change and future migration. Employing such strategies may save the SIDS from sinking into the sea and, at the same time......Climate change poses a serious threat to the world, in particular to the Small Island Developing States (SIDS). The organisation Alliance of Small Island States (AOSIS) represents the SIDS by giving them a voice in the United Nations. We discuss the different aspects of climate change and the role...... that a small actor like AOSIS plays in protecting the citizens of its member states rather than free ride on larger actors. Which strategies should AOSIS use to encourage an even more ambitious climate policy in the future? We suggest five relevant strategies: 1) Introduction of sanctions in the Paris...

  5. Forensic seismology and the sinking of the Kursk (United States)

    Koper, Keith D.; Wallace, Terry C.; Taylor, Steven R.; Hartse, Hans E.

    On August 10, 2000, Russia's Northern Fleet began its largest naval exercise in more than a decade. Among the vessels taking part was the heavily-armed Kursk, an Oscar class submarine that was the most modern cruise-missile sub in the fleet.Beginning on August 14, a series of reports in the press indicated that the Kursk had been severely damaged during the exercise and that the crew were likely dead. By August 17, news agencies were reporting that seismic networks in the Baltic area had detected two seismic events which appeared to correspond to the Kursk disaster in time and space (Figure 1). Specifically the seismic events were consistent with reports from the British Broadcasting Corporation on the location of ongoing rescue efforts. The fact that this section of the Barents Sea is essentially aseismic added credence to the assertion that the seismic events were directly related to the sinking of the Kursk.

  6. Transport of defense compounds from source to sink

    DEFF Research Database (Denmark)

    Jørgensen, Morten Egevang; Nour-Eldin, Hussam Hassan; Halkier, Barbara Ann


    Plants synthesize a plethora of defense compounds crucial for their survival in a challenging and changing environment. Transport processes are important for shaping the distribution pattern of defense compounds, albeit focus hitherto has been mostly on their biosynthetic pathways. A recent...... identification of two glucosinolate transporters represents a breakthrough in our understanding of glucosinolate transport in Arabidopsis and has advanced knowledge in transport of defense compounds. In this review, we discuss the role of the glucosinolate transporters in establishing dynamic glucosinolate...... distribution patterns and source-sink relations. We focus on lessons learned from glucosinolate transport that may apply to transport of other defense compounds and discuss future avenues in the emerging field of defense compound transport....

  7. Sinking into the Sea? Climate Change and AOSIS Strategies

    DEFF Research Database (Denmark)

    Højland, Camille Marie Risager; Svendsen, Gert Tinggaard


    Climate change poses a serious threat to the world, in particular to the Small Island Developing States (SIDS). The organisation Alliance of Small Island States (AOSIS) represents the SIDS by giving them a voice in the United Nations. We discuss the different aspects of climate change and the role...... Agreement, 2) A CO2 tax, 3) Subsidising new green technology, 4) That AOSIS should look for coalition partners, e.g. China, and 5) Even stronger focus on the linkage between climate change and future migration. Employing such strategies may save the SIDS from sinking into the sea and, at the same time...... that a small actor like AOSIS plays in protecting the citizens of its member states rather than free ride on larger actors. Which strategies should AOSIS use to encourage an even more ambitious climate policy in the future? We suggest five relevant strategies: 1) Introduction of sanctions in the Paris...

  8. Role of metabolite transporters in source-sink carbon allocation

    Directory of Open Access Journals (Sweden)

    Frank eLudewig


    Full Text Available Plants assimilate carbon dioxide during photosynthesis in chloroplasts. Assimilated carbon is subsequently allocated throughout the plant. Generally, two types of organs can be distinguished, mature green source leaves as net photoassimilate exporters, and net importers, the sinks, e.g. roots, flowers, small leaves and storage organs like tubers. Within these organs, different tissue types developed according to their respective function, and cells of either tissue type are highly compartmentalized. Photoassimilates are allocated to distinct compartments of these tissues in all organs, requiring a set of metabolite transporters mediating this intercompartmental transfer.The general route of photoassimilates can be briefly described as follows. Upon fixation of carbon dioxide in chloroplasts of mesophyll cells, triose phosphates either enter the cytosol for mainly sucrose formation or remain in the stroma to form transiently stored starch which is degraded during the night and enters the cytosol as maltose or glucose to be further metabolized to sucrose. In both cases, sucrose enters the phloem for long distance transport or is transiently stored in the vacuole, or can be degraded to hexoses which also can be stored in the vacuole.In the majority of plant species, sucrose is actively loaded into the phloem via the apoplast. Following long distance transport, it is released into sink organs, where it enters cells as source of carbon and energy. In storage organs, sucrose can be stored, or carbon derived from sucrose can be stored as starch in plastids, or as oil in oil bodies, or - in combination with nitrogen - as protein in protein storage vacuoles and protein bodies.Here, we focus on transport proteins known for either of these steps, and discuss the implications for yield increase in plants upon genetic engineering of respective transporters.

  9. Dust deposition: iron source or sink? A case study

    Directory of Open Access Journals (Sweden)

    Y. Ye


    Full Text Available A significant decrease of dissolved iron (DFe concentration has been observed after dust addition into mesocosms during the DUst experiment in a low Nutrient low chlorophyll Ecosystem (DUNE, carried out in the summer of 2008. Due to low biological productivity at the experiment site, biological consumption of iron can not explain the magnitude of DFe decrease. To understand processes regulating the observed DFe variation, we simulated the experiment using a one-dimensional model of the Fe biogeochemical cycle, coupled with a simple ecosystem model. Different size classes of particles and particle aggregation are taken into account to describe the particle dynamics. DFe concentration is regulated in the model by dissolution from dust particles and adsorption onto particle surfaces, biological uptake, and photochemical mobilisation of particulate iron.

    The model reproduces the observed DFe decrease after dust addition well. This is essentially explained by particle adsorption and particle aggregation that produces a high export within the first 24 h. The estimated particle adsorption rates range between the measured adsorption rates of soluble iron and those of colloidal iron, indicating both processes controlling the DFe removal during the experiment. A dissolution timescale of 3 days is used in the model, instead of an instantaneous dissolution, underlining the importance of dissolution kinetics on the short-term impact of dust deposition on seawater DFe.

    Sensitivity studies reveal that initial DFe concentration before dust addition was crucial for the net impact of dust addition on DFe during the DUNE experiment. Based on the balance between abiotic sinks and sources of DFe, a critical DFe concentration has been defined, above which dust deposition acts as a net sink of DFe, rather than a source. Taking into account the role of excess iron binding ligands and biotic processes, the critical DFe concentration might be applied to

  10. Sinking during earthquakes: Critical acceleration criteria control drained soil liquefaction (United States)

    Clément, C.; Toussaint, R.; Stojanova, M.; Aharonov, E.


    This article focuses on liquefaction of saturated granular soils, triggered by earthquakes. Liquefaction is defined here as the transition from a rigid state, in which the granular soil layer supports structures placed on its surface, to a fluidlike state, in which structures placed initially on the surface sink to their isostatic depth within the granular layer. We suggest a simple theoretical model for soil liquefaction and show that buoyancy caused by the presence of water inside a granular medium has a dramatic influence on the stability of an intruder resting at the surface of the medium. We confirm this hypothesis by comparison with laboratory experiments and discrete-element numerical simulations. The external excitation representing ground motion during earthquakes is simulated via horizontal sinusoidal oscillations of controlled frequency and amplitude. In the experiments, we use particles only slightly denser than water, which as predicted theoretically increases the effect of liquefaction and allows clear depth-of-sinking measurements. In the simulations, a micromechanical model simulates grains using molecular dynamics with friction between neighbors. The effect of the fluid is captured by taking into account buoyancy effects on the grains when they are immersed. We show that the motion of an intruder inside a granular medium is mainly dependent on the peak acceleration of the ground motion and establish a phase diagram for the conditions under which liquefaction happens, depending on the soil bulk density, friction properties, presence of water, and peak acceleration of the imposed large-scale soil vibrations. We establish that in liquefaction conditions, most cases relax toward an equilibrium position following an exponential in time. We also show that the equilibrium position itself, for most liquefaction regimes, corresponds to the isostatic equilibrium of the intruder inside a medium of effective density. The characteristic time to relaxation is

  11. Transient performance of a thermal energy storage-based heat sink using a liquid metal as the phase change material

    International Nuclear Information System (INIS)

    Fan, Li-Wu; Wu, Yu-Yue; Xiao, Yu-Qi; Zeng, Yi; Zhang, Yi-Ling; Yu, Zi-Tao


    Highlights: • A liquid metal is adopted as the PCM in a thermal energy storage-based heat sink. • Transient performance of the heat sink is tested in comparison to an organic PCM. • The liquid metal has a similar volumetric latent heat of fusion to the organic PCM. • Outperformance of the liquid metal is found due to its higher thermal conductivity. • Liquid metals are preferred when the system weight is less important than volume. - Abstract: In this Technical Note, the use of a liquid metal, i.e., a low melting point Pb–Sn–In–Bi alloy, as the phase change material (PCM) in thermal energy storage-based heat sinks is tested in comparison to an organic PCM (1-octadecanol) having a similar melting point of ∼60 °C. The thermophysical properties of the two types of PCM are characterized, revealing that the liquid metal is much more conductive while both have nearly identical volumetric latent heat of fusion (∼215 MJ/m 3 ). By using at the same volume of 80 mL, i.e., the same energy storage capacity, the liquid metal is shown to outperform significantly over the organic PCM under the various heating powers up to 105.3 W/cm 2 . During the heating period, the use of the liquid metal leads to a remarkable extension of the effective protection time to nearly twice longer as well as a reduction of the highest overheating temperature by up to 50 °C. The cool-down period can also be shortened significantly by taking advantage of the much higher thermal conductivity of the liquid metal. These findings suggest that liquid metals could serve as a promising PCM candidate for particular applications where the volume limit is very rigorous and the penalty in weight increment is acceptable.

  12. Car Detection from Low-Altitude UAV Imagery with the Faster R-CNN

    Directory of Open Access Journals (Sweden)

    Yongzheng Xu


    Full Text Available UAV based traffic monitoring holds distinct advantages over traditional traffic sensors, such as loop detectors, as UAVs have higher mobility, wider field of view, and less impact on the observed traffic. For traffic monitoring from UAV images, the essential but challenging task is vehicle detection. This paper extends the framework of Faster R-CNN for car detection from low-altitude UAV imagery captured over signalized intersections. Experimental results show that Faster R-CNN can achieve promising car detection results compared with other methods. Our tests further demonstrate that Faster R-CNN is robust to illumination changes and cars’ in-plane rotation. Besides, the detection speed of Faster R-CNN is insensitive to the detection load, that is, the number of detected cars in a frame; therefore, the detection speed is almost constant for each frame. In addition, our tests show that Faster R-CNN holds great potential for parking lot car detection. This paper tries to guide the readers to choose the best vehicle detection framework according to their applications. Future research will be focusing on expanding the current framework to detect other transportation modes such as buses, trucks, motorcycles, and bicycles.

  13. Role of bicarbonate as a pH buffer and electron sink in microbial dechlorination of chloroethenes

    Directory of Open Access Journals (Sweden)

    Delgado Anca G


    Full Text Available Abstract Background Buffering to achieve pH control is crucial for successful trichloroethene (TCE anaerobic bioremediation. Bicarbonate (HCO3− is the natural buffer in groundwater and the buffer of choice in the laboratory and at contaminated sites undergoing biological treatment with organohalide respiring microorganisms. However, HCO3− also serves as the electron acceptor for hydrogenotrophic methanogens and hydrogenotrophic homoacetogens, two microbial groups competing with organohalide respirers for hydrogen (H2. We studied the effect of HCO3− as a buffering agent and the effect of HCO3−-consuming reactions in a range of concentrations (2.5-30 mM with an initial pH of 7.5 in H2-fed TCE reductively dechlorinating communities containing Dehalococcoides, hydrogenotrophic methanogens, and hydrogenotrophic homoacetogens. Results Rate differences in TCE dechlorination were observed as a result of added varying HCO3− concentrations due to H2-fed electrons channeled towards methanogenesis and homoacetogenesis and pH increases (up to 8.7 from biological HCO3− consumption. Significantly faster dechlorination rates were noted at all HCO3− concentrations tested when the pH buffering was improved by providing 4-(2-hydroxyethyl-1-piperazineethanesulfonic acid (HEPES as an additional buffer. Electron balances and quantitative PCR revealed that methanogenesis was the main electron sink when the initial HCO3− concentrations were 2.5 and 5 mM, while homoacetogenesis was the dominant process and sink when 10 and 30 mM HCO3− were provided initially. Conclusions Our study reveals that HCO3− is an important variable for bioremediation of chloroethenes as it has a prominent role as an electron acceptor for methanogenesis and homoacetogenesis. It also illustrates the changes in rates and extent of reductive dechlorination resulting from the combined effect of electron donor competition stimulated by HCO3− and the changes in pH exerted by

  14. Tropical secondary forests regenerating after shifting cultivation in the Philippines uplands are important carbon sinks. (United States)

    Mukul, Sharif A; Herbohn, John; Firn, Jennifer


    In the tropics, shifting cultivation has long been attributed to large scale forest degradation, and remains a major source of uncertainty in forest carbon accounting. In the Philippines, shifting cultivation, locally known as kaingin, is a major land-use in upland areas. We measured the distribution and recovery of aboveground biomass carbon along a fallow gradient in post-kaingin secondary forests in an upland area in the Philippines. We found significantly higher carbon in the aboveground total biomass and living woody biomass in old-growth forest, while coarse dead wood biomass carbon was higher in the new fallow sites. For young through to the oldest fallow secondary forests, there was a progressive recovery of biomass carbon evident. Multivariate analysis indicates patch size as an influential factor in explaining the variation in biomass carbon recovery in secondary forests after shifting cultivation. Our study indicates secondary forests after shifting cultivation are substantial carbon sinks and that this capacity to store carbon increases with abandonment age. Large trees contribute most to aboveground biomass. A better understanding of the relative contribution of different biomass sources in aboveground total forest biomass, however, is necessary to fully capture the value of such landscapes from forest management, restoration and conservation perspectives.

  15. Efficient on-chip hotspot removal combined solution of thermoelectric cooler and mini-channel heat sink

    International Nuclear Information System (INIS)

    Hao, Xiaohong; Peng, Bei; Xie, Gongnan; Chen, Yi


    Highlights: • A combined solution of thermoelectric cooler (TEC) and mini-channel heat sink to remove the hotspot of the chip has been proposed. • The TEC's mathematical model is established to assess its work performance. • A comparative study on the proposed efficient On-Chip Hotspot Removal Combined Solution. - Abstract: Hotspot will significantly degrade the reliability and performance of the electronic equipment. The efficient removal of hotspot can make the temperature distribution uniform, and ensure the reliable operation of the electronic equipment. This study proposes a combined solution of thermoelectric cooler (TEC) and mini-channel heat sink to remove the hotspot of the chip in the electronic equipment. Firstly, The TEC's mathematical model is established to assess its work performance under different boundary conditions. Then, the hotspot removal capability of the TEC is discussed for different cooling conditions, which has shown that the combined equipment has better hotspot removal capability compared with others. Finally, A TEC is employed to investigate the hotspot removal capacity of the combined solution, and the results have indicated that it can effectively remove hotspot in the diameter of 0.5 mm, the power density of 600W/cm 2 when its working current is 3A and heat transfer thermal resistance is 0 K/W.

  16. Real-time vehicle detection and tracking in video based on faster R-CNN (United States)

    Zhang, Yongjie; Wang, Jian; Yang, Xin


    Vehicle detection and tracking is a significant part in auxiliary vehicle driving system. Using the traditional detection method based on image information has encountered enormous difficulties, especially in complex background. To solve this problem, a detection method based on deep learning, Faster R-CNN, which has very high detection accuracy and flexibility, is introduced. An algorithm of target tracking with the combination of Camshift and Kalman filter is proposed for vehicle tracking. The computation time of Faster R-CNN cannot achieve realtime detection. We use multi-thread technique to detect and track vehicle by parallel computation for real-time application.

  17. Increasing carbon sinks in European forests: effect of afforestation and changes in mean growing stock volume

    NARCIS (Netherlands)

    Vilén, T.; Cienciala, E.; Schelhaas, M.; Verkerk, P.J.; Lindner, M.; Peltola, H.


    In Europe, both forest area and growing stock have increased since the 1950s, and European forests have acted as a carbon sink during the last six decades. However, the contribution of different factors affecting the sink is not yet clear. In this study, historical inventory data were combined with

  18. A Descriptive Study of Pre-Service Science Teachers' Misconceptions about Sinking-Floating (United States)

    Kiray, Seyit Ahmet; Aktan, Filiz; Kaynar, Hamza; Kilinc, Sena; Gorkemli, Tugce


    The purpose of this study is twofold. Firstly, it attempts to determine the pre-service science teachers' misconceptions about floating and sinking. Secondly, it aims to reveal the level of pre-service science teachers' misconceptions, scientific knowledge, lack of knowledge, and lack of confidence related to floating and sinking. To conduct the…

  19. Data dissemination of emergency messages in mobile multi-sink wireless sensor networks

    NARCIS (Netherlands)

    Erman-Tüysüz, A.; Havinga, Paul J.M.

    In wireless sensor networks (WSNs), data dissemination is generally performed from sensor nodes to a static sink. If the data under consideration is an emergency message such as a fire alarm, it must be transmitted as fast and reliably as possible towards the sink of WSN. In such mission critical

  20. Thermodynamic optimization of heat/cold sink extenders in thermoelectric cooling assemblies

    International Nuclear Information System (INIS)

    Lau, P.G.; Ritzer, T.M.; Buist, R.J.


    The heat sink extender serves many purposes in the overall design of thermoelectric cooling assembly. One purpose is to serve as a thermojunction, another involves temperature control. The optimization of the heat sink extender is discussed and several schemes are considered

  1. An Application of Path Sharing To Routing For Mobile Sinks In ...

    African Journals Online (AJOL)

    CODEXT protocol for optimizing routing to multiple sinks through reinforcement learning. Such a routing situation arises in WSNs with multiple, possibly mobile sinks, such as WSNs with actuators deployed in parallel to sensors. This protocol is based on GAF protocol and grid structure to reduce energy consumed.

  2. On the estimation method of compressed air consumption during pneumatic caisson sinking


    平川, 修治; ヒラカワ, シュウジ; Shuji, HIRAKAWA


    There are several methods in estimation of compressed air consumption during pneumatic caisson sinking. It is re uired in the estimation of compressed air consumption by the methods under the same conditions. In this paper, it is proposed the methods which is able to estimate accurately the compressed air consumption during pnbumatic caissons sinking at this moment.

  3. The Global Carbon Sink in Tidal Salt Marshes (United States)

    Chmura, G. L.


    For decades researchers have concentrated on proving that C is exported from salt marshes to coastal waters, with limited success. Yet, the C retained in the marsh soils may be equally important. Presumptions that minor amounts of C are stored in salt marsh soils are based upon measurements of low percentages of C in many marshes. Simply measuring the organic matter content of marsh soils provides little indication of the amount or rate of C stored, as this parameter is based upon the percent by mass of the soil. The critical parameter to calculate is C density, derived from percent organic matter and bulk density. (The latter is often neglected in marsh soil studies.) Calculation of C density reveals that minerogenic soils with high bulk densities may have C densities or C storage rates equivalent to more organic soils with low bulk densities. A global average soil C density of 0.055 ± 0.004 g cm-3 has been calculated from 107 measurements reported for salt marshes around the world (Gulf of Mexico, NE and NW Atlantic, Mediterranean and NE Pacific). Assuming an average marsh soil depth of 0.5 m and using inventories of marsh area available for Europe, Scandinavia, Africa, Canada and the U.S., the C stored globally in salt marshes is greater than 430 ± 30 Tg C. The global carbon storage could be twice this as there are no marsh inventories available for Asia or South America. Rates of C storage can be calculated from 96 C density measurements where soil accretion rates also were measured. Globally, marshes sequester an average of 210 g CO2 m-2 yr-1, an order of magnitude greater than rates reported for peatlands. Salt marsh C storage can have regional importance. At a magnitude of 5 Tg C yr-1, tidal wetlands comprise 1--2 percent of the C sink (300--580 Tg C yr-1) estimated for the coterminous U.S. In the Bay of Fundy restoration of salt marshes reclaimed for agricultural land could enable sequestration of an additional 240 to 360 Gg C yr-1, equivalent to 4 to 6

  4. Analytical Thermal and Cost Optimization of Micro-Structured Plate-Fin Heat Sink

    DEFF Research Database (Denmark)

    Rezaniakolaei, Alireza; Rosendahl, Lasse

    the thermal resistance and to maximize the cost performance of the heat sink. The width and the height of the microchannels, and the fin thickness are analytically optimized at a wide range of pumping power. Using an effective numeric test, the generated equations also discuss the optimum parameters at three......Microchannel heat sinks have been widely used in the field of thermo-fluids due to the rapid growth in technological applications which require high rates of heat transfer in relatively small spaces and volumes. In this work, a micro plate-fin heat sink is optimized parametrically, to minimize...... sizes of the substrate plat of the heat sink. Results show that, at any pumping power there are specific values of the channel width and fin thickness which produce minimum thermal resistance in the heat sink. The results also illustrate that, a larger channel width and a smaller fin thickness lead...

  5. The relative importance of methane sources and sinks over the Last Interglacial period and into the last glaciation (United States)

    Quiquet, A.; Archibald, A. T.; Friend, A. D.; Chappellaz, J.; Levine, J. G.; Stone, E. J.; Telford, P. J.; Pyle, J. A.


    All recent climatic projections for the next century suggest that we are heading towards a warmer climate than today (Intergovernmental Panel on Climate Change; Fifth Assessment Report), driven by increasing atmospheric burdens of anthropogenic greenhouse gases. In particular, the volume mixing ratio of methane, the second-most important anthropogenic greenhouse gas, has increased by a factor of ˜2.5 from the beginning of the European Industrial Revolution. Due to their complex responses to climatic factors, understanding of the dynamics of future global methane emissions and sinks is crucial for the next generation of climate projections. Of relevance to this problem, the Earth likely experienced warmer average temperatures than today during the Last Interglacial (LIG) period (130-115 kaBP). Interestingly, ice cores do not indicate a different methane mixing ratio from the Pre-Industrial Holocene (PIH), in other words the current interglacial period prior to anthropogenic influence. This is surprising as warmer temperatures might be expected to increase methane emissions. The present study aims to improve our understanding of the changes in the global methane budget through quantifying the relative importance of sources and sinks of methane during the last full glacial-interglacial cycle. A fairly limited number of studies have investigated this cycle at the millenium time scale with most of them examining the doubling in CH4 from the Last Glacial Maximum (LGM) to the PIH. Though it is still a matter of debate, a general consensus suggests a predominant role to the change in methane emissions from wetlands and only a limited change in the oxidising capacity of the atmosphere. In the present study we provide an estimate of the relative importance of sources and sinks during the LIG period, using a complex climate-chemistry model to quantify the sinks, and a methane emissions model included in a global land surface model, for the sources. We are not aware of any

  6. Superinfection with a heterologous HIV strain per se does not lead to faster progression

    NARCIS (Netherlands)

    Fung, Isaac Chun-Hai; Gambhir, Manoj; van Sighem, Ard; de Wolf, Frank; Garnett, Geoffrey P.


    It has been suggested that superinfection of HIV positive individuals with heterologous HIV strains could lead to faster progression to AIDS, generating concern over the risks of exposure to new infections in those already infected. A mathematical model of the within-host dynamics of two sequential

  7. More Symmetrical Children Have Faster and More Consistent Choice Reaction Times (United States)

    Hope, David; Bates, Timothy C.; Dykiert, Dominika; Der, Geoff; Deary, Ian J.


    Greater cognitive ability in childhood is associated with increased longevity, and speedier reaction time (RT) might account for much of this linkage. Greater bodily symmetry is linked to both higher cognitive test scores and faster RTs. It is possible, then, that differences in bodily system integrity indexed by symmetry may underlie the…

  8. Faster heme loss from hemoglobin E than HbS, in acidic pH: Effect ...

    Indian Academy of Sciences (India)

    This is also of particular importance to membranes containing the aminophospholipid and cholesterol which are predominantly localized in .... pids and cholesterol, prevalent in erythrocyte membranes. The present work indicated faster ..... heme for egg lecithin vesicles is quite high, with the partition constant for going from ...

  9. Faster Reaching in Chronic Spastic Stroke Patients Comes at the Expense of Arm-Trunk Coordination. (United States)

    Mandon, Laurence; Boudarham, Julien; Robertson, Johanna; Bensmail, Djamel; Roche, Nicolas; Roby-Brami, Agnès


    The velocity of reaching movements is often reduced in patients with stroke-related hemiparesis; however, they are able to voluntarily increase paretic hand velocity. Previous studies have proposed that faster speed improves movement quality. To investigate the combined effects of reaching distance and speed instruction on trunk and paretic upper-limb coordination. The hypothesis was that increased speed would reduce elbow extension and increase compensatory trunk movement. A single session study in which reaching kinematics were recorded in a group of 14 patients with spastic hemiparesis. A 3-dimensional motion analysis system was used to track the trajectories of 5 reflective markers fixed on the finger, wrist, elbow, acromion, and sternum. The reaching movements were performed to 2 targets at 60% and 90% arm length, respectively, at preferred and maximum velocity. The experiment was repeated with the trunk restrained by a strap. All the patients were able to voluntarily increase reaching velocity. In the trunk free, faster speed condition, elbow extension velocity increased but elbow extension amplitude decreased and trunk movement increased. In the trunk restraint condition, elbow extension amplitude did not decrease with faster speed. Seven patients scaled elbow extension and elbow extension velocity as a function of reach distance, the other 7 mainly increased trunk compensation with increased task constraints. There were no clear clinical characteristics that could explain this difference. Faster speed may encourage some patients to use compensation. Individual indications for therapy could be based on a quantitative analysis of reaching coordination. © The Author(s) 2015.

  10. Variation in promiscuity and sexual selection drives avian rate of Faster-Z evolution. (United States)

    Wright, Alison E; Harrison, Peter W; Zimmer, Fabian; Montgomery, Stephen H; Pointer, Marie A; Mank, Judith E


    Higher rates of coding sequence evolution have been observed on the Z chromosome relative to the autosomes across a wide range of species. However, despite a considerable body of theory, we lack empirical evidence explaining variation in the strength of the Faster-Z Effect. To assess the magnitude and drivers of Faster-Z Evolution, we assembled six de novo transcriptomes, spanning 90 million years of avian evolution. Our analysis combines expression, sequence and polymorphism data with measures of sperm competition and promiscuity. In doing so, we present the first empirical evidence demonstrating the positive relationship between Faster-Z Effect and measures of promiscuity, and therefore variance in male mating success. Our results from multiple lines of evidence indicate that selection is less effective on the Z chromosome, particularly in promiscuous species, and that Faster-Z Evolution in birds is due primarily to genetic drift. Our results reveal the power of mating system and sexual selection in shaping broad patterns in genome evolution. © 2015 John Wiley & Sons Ltd.

  11. Pedestrian crowd dynamics in merging sections: Revisiting the ;faster-is-slower; phenomenon (United States)

    Shahhoseini, Zahra; Sarvi, Majid; Saberi, Meead


    The study of the discharge of active or self-driven matter in narrow passages has become of the growing interest in a variety of fields. The question has particularly important practical applications for the safety of pedestrian human flows notably in emergency scenarios. It has been suggested predominantly through simulation in some theoretical studies as well as through few experimentations that under certain circumstances, an elevated vigour to escape may exacerbate the outflow and cause further delay although the experimental evidence is rather mixed. The dimensions of this complex phenomenon known as the "faster-is slower" effect are of crucial importance to be understood owing to its potential practical implications for the emergency management. The contextual requirements of observing this phenomenon are yet to be identified. It is not clear whether a "do not speed up" policy is universally beneficial and advisable in an evacuation scenario. Here for the first time we experimentally examine this phenomenon in relation to the pedestrian flows at merging sections as a common geometric feature of crowd egress. Various merging angles and three different speed regimes were examined in high-density laboratory experiments. The measurements of flow interruptions and egress efficiency all indicated that the pedestrians were discharged faster when moving at elevated speed levels. We also observed clear dependencies between the discharge rate and the physical layout of the merging with certain designs clearly outperforming others. But regardless of the design, we observed faster throughput and greater avalanche sizes when we instructed pedestrians to run. Our results give the suggestion that observation of the faster-is-slower effect may necessitate certain critical conditions including passages being overly narrow relative to the size of participles (pedestrians) to create long-lasting blockages. The faster-is-slower assumption may not be universal and there may be

  12. How phosphorus limitation can control climatic gas sources and sinks (United States)

    Gypens, Nathalie; Borges, Alberto V.; Ghyoot, Caroline


    Since the 1950's, anthropogenic activities severely increased river nutrient loads in European coastal areas. Subsequent implementation of nutrient reduction policies have considerably reduced phosphorus (P) loads from mid-1980's, while nitrogen (N) loads were maintained, inducing a P limitation of phytoplankton growth in many eutrophied coastal areas such as the Southern Bight of the North Sea (SBNS). When dissolved inorganic phosphorous (DIP) is limiting, most phytoplankton organisms are able to indirectly acquire P from dissolved organic P (DOP). We investigate the impact of DOP use on the importance of phytoplankton production and atmospheric fluxes of CO2 and dimethylsulfide (DMS) in the SBNS from 1951 to 2007 using an extended version of the R-MIRO-BIOGAS model. This model includes a description of the ability of phytoplankton organisms to use DOP as a source of P. Results show that primary production can increase up to 70% due to DOP uptake in limiting DIP conditions. Consequently, simulated DMS emissions double while CO2 emissions to the atmosphere decrease, relative to the reference simulation without DOP uptake. At the end of the simulated period (late 2000's), the net direction of air-sea CO2 annual flux, changed from a source to a sink for atmospheric CO2 in response to use of DOP and increase of primary production.

  13. Managing carbon sinks by changing rotation length in European forests

    Energy Technology Data Exchange (ETDEWEB)

    Kaipainen, Terhi; Liski, Jari; Pussinen, Ari; Karjalainen, Timo


    Elongation of rotation length is a forest management activity countries may choose to apply under Article 3.4 of the Kyoto Protocol to help them meet their commitments for reduction of greenhouse gas emissions. We used the CO2FIX model to analyze how the carbon stocks of trees, soil and wood products depend on rotation length in different European forests. Results predicted that the carbon stock of trees increased in each forest when rotation length was increased, but the carbon stock of soil decreased slightly in German and Finnish Scots pine forests; the carbon stock of wood products also decreased slightly in cases other than the Sitka spruce forest in UK. To estimate the efficiency of increasing rotation length as an Article 3.4 activity, we looked at changes in the carbon stock of trees resulting from a 20-year increase in current rotation lengths. To achieve the largest eligible carbon sink mentioned in Article 3.4 of the Kyoto Protocol, the rotation lengths need to be increased on areas varying from 0.3 to 5.1 Mha depending on the forest. This would in some forests cause 1-6% declines in harvesting possibilities. The possible decreases in the carbon stock of soil indicate that reporting the changes in the carbon stocks of forests under Article 3.4 may require measuring soil carbon.

  14. Source-sink driven planetary flows in a polar basin (United States)

    Gavilan Pascual-Ahuir, Estanislao; Willmott, Andrew; Luneva, Maria; Morales Maqueda, Miguel


    Analytical process models are developed to study linear, steady-state, source-sink and wind stress curl driven barotropic planetary flows in a circular polar basin on the sphere with simple shelf topography. The leading order dynamical balance is geostrophic except near the boundary of the basin and the shelf edge, where dissipation in the form of either linear bottom friction or eddy diffusion becomes significant. Full spherical geometry is retained in the derivation of the barotropic vorticity equation. Subsequently, an overlooked approximation in the refereed literature of the sixties is adopted whereby the latitudinal dependence in the coefficients of the vorticity equation are suppressed, hence allowing analytical solutions to be obtained we refer to this as the "beta sphere approximation". The approximation is justified, a posteriori, and the study compares the analytical solutions with numerical solutions obtained from the NEMO ocean modelling system. Numerical experiments with NEMO are used to extend the process model solutions by obtaining the steady wind and boundary forced circulation in a polar basin with open boundaries representing the Bering Strait, Canadian Archipelago and Greenland Sea, and with a continental self and a representation of the Lomonosov ridge. NEMO based experiments are also conducted to investigate the sea surface anomaly field driven by the fluctuating flow through one, or more, of the straits connecting the Arctic basin to its marginal seas. Finally, we reflect on the likely impact of sea ice on the barotropic circulation in the Arctic Ocean.

  15. Long-period astronomically-forced terrestrial carbon sinks (United States)

    Valero, Luis; Cabrera, Lluís; Sáez, Alberto; Garcés, Miguel


    Sequestration of organic matter by peat accumulation constitutes a primary sink for carbon in the global carbon cycle. The processes that control the formation and storage of peat at geological time scales are poorly understood but are of a non-solved issue of fundamental importance for understanding the global climate system. We analyzed a 7 million years long terrestrial record of Late Oligocene age from the As Pontes Basin in Northern Spain, which demonstrates that minima in the 405-kyr and 2.4-Myr eccentricity cycles play a key role in peat formation. Such nodes exhibit reduced precession amplitudes, thus avoiding extremes in seasons and seasonal contrast for a prolonged period of time. In the As Pontes Basin, this orbital configuration is associated with a decrease in siliciclastic sedimentation and enhanced peat formation. Feedbacks between equilibrium landscapes and ecosystem stability will lead to a deceleration of weathering and erosion rates in catchment areas and to minimum and stable sediment flux along the sediment routing system. Mid-latitude peat burial could contribute to disturb the carbon cycle by removing (atmospheric) carbon at times of minimum eccentricity.

  16. The deep sea is a major sink for microplastic debris (United States)

    Woodall, Lucy C.; Sanchez-Vidal, Anna; Canals, Miquel; Paterson, Gordon L.J.; Coppock, Rachel; Sleight, Victoria; Calafat, Antonio; Rogers, Alex D.; Narayanaswamy, Bhavani E.; Thompson, Richard C.


    Marine debris, mostly consisting of plastic, is a global problem, negatively impacting wildlife, tourism and shipping. However, despite the durability of plastic, and the exponential increase in its production, monitoring data show limited evidence of concomitant increasing concentrations in marine habitats. There appears to be a considerable proportion of the manufactured plastic that is unaccounted for in surveys tracking the fate of environmental plastics. Even the discovery of widespread accumulation of microscopic fragments (microplastics) in oceanic gyres and shallow water sediments is unable to explain the missing fraction. Here, we show that deep-sea sediments are a likely sink for microplastics. Microplastic, in the form of fibres, was up to four orders of magnitude more abundant (per unit volume) in deep-sea sediments from the Atlantic Ocean, Mediterranean Sea and Indian Ocean than in contaminated sea-surface waters. Our results show evidence for a large and hitherto unknown repository of microplastics. The dominance of microfibres points to a previously underreported and unsampled plastic fraction. Given the vastness of the deep sea and the prevalence of microplastics at all sites we investigated, the deep-sea floor appears to provide an answer to the question—where is all the plastic? PMID:26064573

  17. OPG's approach of crediting natural circulation in outage heat sinks

    International Nuclear Information System (INIS)

    Fung, K.K.; Mackinnon, J.C.


    A review of crediting natural circulation as a backup means of removing the reactor core decay heat during an outage in Ontario Power Generation's nuclear stations was completed in 2000. The objective was to define the configurations and conditions under which natural circulation can be confidently credited as an effective heat transport mechanism for use in shutdown heat sink management. The project was an interdisciplinary program, and involved analyses in the areas of heat transport system thermalhydaulics, fuel and fuel channel thermal and mechanical behaviour, radiation physics, and probabilistic risks. The assessment shows that it is economically acceptable to credit natural circulation as a backup means of removing the core decay heat whenever the no fuel failure criteria are met. The economic risks associated with such a potential use decrease with time after shutdown. The waiting times after shutdown when there would be various levels of risks of damaging the pressure tubes and fuel bundles were derived for use in planning maintenance activities so as to minimize the economic risks. (author)

  18. Total iron binding capacity (United States)

    ... page: // Total iron binding capacity To use the sharing features on this page, please enable JavaScript. Total iron binding capacity (TIBC) is a blood test to ...

  19. Choice of quantum dot materials for fabricating memory devices with longer storage and faster writing of information (United States)

    Damodaran, V.; Ghosh, Kaustab


    We present theoretical modelling and simulation approach for studying the electron and hole dynamics in various III-V quantum dot (QD) device systems for high performance memory applications. A rigorous computation is carried out by developing a self-consistent Schrödinger Poisson solver for obtaining the potential state of the QD for various applied voltages of the device. A detailed capture as well as emission mechanism of the carriers is elucidated at various operating temperatures ranging from 10 to 300 K. Our results showed suitability of holes in GaSb/GaAs dots for 107 times increase in the duration of data storage and 34 times faster writing capability as compared to InAs/GaAs QDs at room temperature operation. A trade-off is necessary between extending the storage time and increasing the write time by incorporation of high bandgap AlAs barrier. However, a technique is proposed to avoid the trade-off and minimize the write and erase time along with longer storage of data for QD memories with barrier layers. Our computation also reveals greater retention capacity of electrons over holes when localized to the same potential barrier. Applications of these QDs at cryogenic temperatures are also elucidated. Thus, based on our comparative analysis, valuable information is being provided to the device scientist in choosing suitable quantum dot material for memory devices and optimizing its performance.

  20. Mitochondrial Uncoupling Protein 1 Overexpression Increases Yield in Nicotiana tabacum under Drought Stress by Improving Source and Sink Metabolism

    Directory of Open Access Journals (Sweden)

    Pedro Barreto


    Full Text Available Mitochondrial uncoupling proteins (UCPs sustain mitochondrial respiration independent of intracellular ATP concentration. Uncoupled respiration is particularly beneficial under stress conditions, during which both photosynthesis and respiration may be impaired. Sustaining carbon fixation during the reproductive phase is essential for plants to develop viable pollen grains and for seed setting. Here, we examined whether UCP1 overexpression (UCP1-oe would help tobacco plants cope with drought stress during reproductive development. We observed that WT and UCP1-oe plants lost water at the same rate under moderate drought stress, but that UCP1-oe lines regained water faster upon rewatering. UCP1-oe plants maintained higher levels of respiration and photosynthesis and decreased H2O2 content in the leaves during the drought stress period. We examined whether UCP1-oe impacts reproductive tissues and seed production by monitoring the progress of flower development, focusing on the early stages of pollen formation. UCP1-oe lines induced the expression of mitochondrial genes and increased mtDNA content in reproductive tissues, which increased the consumption of carbohydrates and reduced H2O2 content and pollen disturbances. Finally, the beneficial impact of UCP1-oe on the source and sink organs resulted in an increased seed size and number under both control conditions and drought stress.

  1. SCODE: A Secure Coordination-Based Data Dissemination to Mobile Sinks in Sensor Networks (United States)

    Hung, Lexuan; Lee, Sungyoung; Lee, Young-Koo; Lee, Heejo

    For many sensor network applications such as military, homeland security, it is necessary for users (sinks) to access sensor networks while they are moving. However, sink mobility brings new challenges to secure routing in large-scale sensor networks. Mobile sinks have to constantly propagate their current location to all nodes, and these nodes need to exchange messages with each other so that the sensor network can establish and maintain a secure multi-hop path between a source node and a mobile sink. This causes significant computation and communication overhead for sensor nodes. Previous studies on sink mobility have mainly focused on efficiency and effectiveness of data dissemination without security consideration. In this paper, we propose a secure and energy-efficient data dissemination protocol — Secure COodination-based Data dissEmination (SCODE) — for mobile sinks in sensor networks. We take advantages of coordination networks (grid structure) based on Geographical Adaptive Fidelity (GAF) protocol to construct a secure and efficient routing path between sources and sinks. Our security analysis demonstrates that the proposed protocol can defend against common attacks in sensor network routing such as replay attacks, selective forwarding attacks, sinkhole and wormhole, Sybil attacks, HELLO flood attacks. Our performance evaluation both in mathematical analysis and simulation shows that the SCODE significantly reduces communication overhead and energy consumption while the latency is similar compared with the existing routing protocols, and it always delivers more than 90 percentage of packets successfully.

  2. Characterization of Radial Curved Fin Heat Sink under Natural and Forced Convection (United States)

    Khadke, Rishikesh; Bhole, Kiran


    Heat exchangers are important structures widely used in power plants, food industries, refrigeration, and air conditioners and now widely used in computing systems. Finned type of heat sink is widely used in computing systems. The main aim of the design of the heat sink is to maintain the optimum temperature level. To achieve this goal so many geometrical configurations are implemented. This paper presents a characterization of radially curved fin heat sink under natural and forced convection. Forced convection is studied for the optimization of temperature for better efficiency. The different alternatives in geometry are considered in characterization are heat intensity, the height of the fin and speed of the fan. By recognizing these alternatives the heat sink is characterized by the heat flux usually generated in high-end PCs. The temperature drop characteristics across height and radial direction are presented for the constant heat input and air flow in the heat sink. The effect of dimensionless elevation height (0 ≤ Z* ≤ 1) and Elenbaas Number (0.4 ≤ El ≤ 2.8) of the heat sink were investigated for study of the Nusselt number. Based on experimental characterization, process plan has been developed for the selection of the similar heat sinks for desired output (heat dissipation and temperature distribution).

  3. Heat sink design considerations in medium power electronic applications with long power cycles

    CERN Document Server

    AUTHOR|(SzGeCERN)744611; Papastergiou, Konstantinos; Thiringer, Torbjörn; Bongiorno, Massimo


    The aim of this work is to investigate the impact of the heat sink thickness and material, as well as, of the convection coefficient of the water cooling system on the power-electronics module thermal stressing. The heat extraction capability of different thicknesses is tested. It is concluded that the thickest heat sink results in marginally lower temperature variation at the junction level compared to the second thickest one. In the thickest heat sink case, the linear dependence of the thermal resistance on the thickness counteracts the benefit of the increased thermal capacitance. The increase in the cooling medium flow rate, which corresponds to an increase in the convection coefficient between the heat sink bottom surface and the water, can be avoided by increasing the thickness of the heat sink. In this way, the energy consumption of the cooling system is reduced. The increase in the flow rate drastically reduces the thermal stressing in the thinnest heat sink case. The increase of the heat sink thickne...

  4. Source-sink interaction: a century old concept under the light of modern molecular systems biology. (United States)

    Chang, Tian-Gen; Zhu, Xin-Guang; Raines, Christine


    Many approaches to engineer source strength have been proposed to enhance crop yield potential. However, a well-co-ordinated source-sink relationship is required finally to realize the promised increase in crop yield potential in the farmer's field. Source-sink interaction has been intensively studied for decades, and a vast amount of knowledge about the interaction in different crops and under different environments has been accumulated. In this review, we first introduce the basic concepts of source, sink and their interactions, then summarize current understanding of how source and sink can be manipulated through both environmental control and genetic manipulations. We show that the source-sink interaction underlies the diverse responses of crops to the same perturbations and argue that development of a molecular systems model of source-sink interaction is required towards a rational manipulation of the source-sink relationship for increased yield. We finally discuss both bottom-up and top-down routes to develop such a model and emphasize that a community effort is needed for development of this model. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email:

  5. An Energy Efficient Distance-Aware Routing Algorithm with Multiple Mobile Sinks for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jin Wang


    Full Text Available Traffic patterns in wireless sensor networks (WSNs usually follow a many-to-one model. Sensor nodes close to static sinks will deplete their limited energy more rapidly than other sensors, since they will have more data to forward during multihop transmission. This will cause network partition, isolated nodes and much shortened network lifetime. Thus, how to balance energy consumption for sensor nodes is an important research issue. In recent years, exploiting sink mobility technology in WSNs has attracted much research attention because it can not only improve energy efficiency, but prolong network lifetime. In this paper, we propose an energy efficient distance-aware routing algorithm with multiple mobile sink for WSNs, where sink nodes will move with a certain speed along the network boundary to collect monitored data. We study the influence of multiple mobile sink nodes on energy consumption and network lifetime, and we mainly focus on the selection of mobile sink node number and the selection of parking positions, as well as their impact on performance metrics above. We can see that both mobile sink node number and the selection of parking position have important influence on network performance. Simulation results show that our proposed routing algorithm has better performance than traditional routing ones in terms of energy consumption.

  6. Responsibility and Capacities

    DEFF Research Database (Denmark)

    Ryberg, Jesper


    That responsible moral agency presupposes certain mental capacities, constitutes a widely accepted view among theorists. Moreover, it is often assumed that degrees in the development of the relevant capacities co-vary with degrees of responsibility. In this article it is argued that, the move from...... the view that responsibility requires certain mental capacities to the position that degrees of responsibility co-vary with degrees of the development of the mental capacities, is premature....

  7. Sinking Deltas are Trapped in a Dual Lock-in of Technology and Institutions: Exploring the Trap and 3 Steps to Break Out. (United States)

    Seijger, C.; Janssen, S.; Erkens, G.


    Although the topic of sinking deltas has been put convincingly in the academic spotlight, we consider it highly unlikely that neither subsidence nor the resulting damage will reduce in the near future as subsiding deltas are trapped in a dual lock-in of technology and institutions. People, and the engineering technologies they have applied, are root causes for sinking deltas worldwide. To serve growing economics and populations, conventional water management strategies have increasingly been implemented (more dikes, dams, groundwater pumping, land reclamation) that cause, exacerbate, or facilitate subsidence. The increasing implementation of these strategies enlarged the power of those implementing it: in the US, an increase in dam and levee construction projects meant an increase in power of the US Army Corps of Engineers; in groundwater irrigation, rich farmers have the capacity to monopolise groundwater over poorer farmers; and key beneficiaries of more hydropower projects in China are the hydropower companies. Nine factors for the lock-in are introduced and illustrated for delta regions in Asia, Europe, and the US. The lock-in factors describe financial, social and technological reasons why certain institutions and technologies become dominant over alternatives. Sinking deltas like the Mekong or Mississippi Delta are thus trapped in a dual lock-in and on a self-reinforcing path of delta development with increasing areas of deltas sinking below sea level. Due to the persistency of these developments, pathways for change are needed. We propose three steps to break the dual lock-in (see Figure): (1) getting to know the lock-in through transdisciplinary research (2 years) (2) temporarily bypass it through experiments in technology and institutions (10 years) (3) constitute a new, more sustainable lock-in by mainstreaming shifts in technology and institutions (10-50 years) The dual lock-in concept offers a novel integrated understanding on sinking deltas

  8. CDMA systems capacity engineering

    CERN Document Server

    Kim, Kiseon


    This new hands-on resource tackles capacity planning and engineering issues that are crucial to optimizing wireless communication systems performance. Going beyond the system physical level and investigating CDMA system capacity at the service level, this volume is the single-source for engineering and analyzing systems capacity and resources.

  9. When are fish sources vs. sinks of nutrients in lake ecosystems? (United States)

    Vanni, Michael J; Boros, Gergely; McIntyre, Peter B


    Animals can be important in nutrient cycling through a variety of direct and indirect pathways. A high biomass of animals often represents a large pool of nutrients, leading some ecologists to argue that animal assemblages can represent nutrient sinks within ecosystems. The role of animals as sources vs. sinks of nutrients has been debated particularly extensively for freshwater fishes. We argue that a large pool size does not equate to a nutrient sink; rather, animals can be nutrient sinks when their biomass increases, when emigration rates are high, and/or when nutrients in animal carcasses are not remineralized. To further explore these ideas, we use a simple model to evaluate the conditions under which fish are phosphorus (P) sources or sinks at the ecosystem (lake) level, and at the habitat level (benthic and water column habitats). Our simulations suggest that, under most conditions, fish are sinks for benthic P but are net P sources to the water column. However, P source and sink strengths depend on fish feeding habits (proportion of P consumed from the benthos and water column), migration patterns, and especially the fate of carcass P. Of particular importance is the rate at which carcasses are mineralized and the relative importance of benthic vs. pelagic primary producers in taking up mineralized P (and excreted P). Higher proportional uptake of P by benthic primary producers increases the likelihood that fish are sinks for water column P. Carcass bones and scales are relatively recalcitrant and can represent a P sink even if fish biomass does not change over time. Thus, there is a need for better documentation of the fraction of carcass P that is remineralized, and the fate of this P, under natural conditions. We urge a more holistic perspective regarding the role of animals in nutrient cycling, with a focus on quantifying the rates at which animals consume, store, release, and transport nutrients under various conditions.

  10. Sink or Swim: The Marine Corps Capacity to Conduct a Marine Expeditionary Brigade Amphibious Assault using Expeditionary Maneuver Warfare (United States)


    RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 15-03-2010 2. REPORT TYPE Master’s Thesis 3. DATES COVERED (From - To) JUN...with the new high-speed hovercraft , known as landing craft, air-cushioned, or LCAC. There were seventeen of these high speed heavy lifters in the Gulf

  11. Methyl bromide: ocean sources, ocean sinks, and climate sensitivity. (United States)

    Anbar, A D; Yung, Y L; Chavez, F P


    The oceans play an important role in the geochemical cycle of methyl bromide (CH3Br), the major carrier of O3-destroying bromine to the stratosphere. The quantity of CH3Br produced annually in seawater is comparable to the amount entering the atmosphere each year from natural and anthropogenic sources. The production mechanism is unknown but may be biological. Most of this CH3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmosphere is poorly constrained; measurements in seawater and the atmosphere have been used to justify both a large oceanic CH3Br flux to the atmosphere and a small net ocean sink. Since the consumption reactions are extremely temperature-sensitive, small temperature variations have large effects on the CH3Br concentration in seawater, and therefore on the exchange between the atmosphere and the ocean. The net CH3Br flux is also sensitive to variations in the rate of CH3Br production. We have quantified these effects using a simple steady state mass balance model. When CH3Br production rates are linearly scaled with seawater chlorophyll content, this model reproduces the latitudinal variations in marine CH3Br concentrations observed in the east Pacific Ocean by Singh et al. [1983] and by Lobert et al. [1995]. The apparent correlation of CH3Br production with primary production explains the discrepancies between the two observational studies, strengthening recent suggestions that the open ocean is a small net sink for atmospheric CH3Br, rather than a large net source. The Southern Ocean is implicated as a possible large net source of CH3Br to the atmosphere. Since our model indicates that both the direction and magnitude of CH3Br exchange between the atmosphere and ocean are extremely sensitive to temperature and marine productivity, and since the rate of CH3Br production in the oceans is comparable to the rate at which this compound is introduced to the atmosphere, even small

  12. Acetone in the atmosphere: Distribution, sources, and sinks (United States)

    Singh, H. B.; O'Hara, D.; Herlth, D.; Sachse, W.; Blake, D. R.; Bradshaw, J. D.; Kanakidou, M.; Crutzen, P. J.


    Acetone (CH3COCH3) was found to be the dominant nonmethane organic species present in the atmosphere sampled primarily over eastern Canada (0-6 km, 35 deg-65 deg N) during ABLE3B (July to August 1990). A concentration range of 357 to 2310 ppt (= 10(exp -12) v/v) with a mean value of 1140 +/- 413 ppt was measured. Under extremely clean conditions, generally involving Arctic flows, lowest (background) mixing ratios of 550 +/- 100 ppt were present in much of the troposphere studied. Correlations between atmospheric mixing ratios of acetone and select species such as C2H2, CO, C3H8, C2Cl4 and isoprene provided important clues to its possible sources and to the causes of its atmospheric variability. Biomass burning as a source of acetone has been identified for the first time. By using atmospheric data and three-dimensional photochemical models, a global acetone source of 40-60 Tg (= 10(exp 12) g)/yr is estimated to be present. Secondary formation from the atmospheric oxidation of precursor hydrocarbons (principally propane, isobutane, and isobutene) provides the single largest source (51%). The remainder is attributable to biomass burning (26%), direct biogenic emissions (21%), and primary anthropogenic emissions (3%). Atmospheric removal of acetone is estimated to be due to photolysis (64%), reaction with OH radicals (24%), and deposition (12%). Model calculations also suggest that acetone photolysis contributed significantly to PAN formation (100-200 ppt) in the middle and upper troposphere of the sampled region and may be important globally. While the source-sink equation appears to be roughly balanced, much more atmospheric and source data, especially from the southern hemisphere, are needed to reliably quantify the atmospheric budget of acetone.

  13. Sink- or Source-driven Phanerozoic carbon cycle? (United States)

    Godderis, Y.; Donnadieu, Y.; Maffre, P.; Carretier, S.


    The Phanerozoic evolution of the atmospheric CO2 level is controlled by the fluxes entering or leaving the exospheric system. Those fluxes (including continental weathering, magmatic degassing, organic carbon burial, oxidation of sedimentary organic carbon) are intertwined, and their relative importance in driving the global carbon cycle evolution may have fluctuated through time. Deciphering the causes of the Phanerozoic climate evolution thus requires a holistic and quantitative approach. Here we focus on the role played by the paleogeographic configuration on the efficiency of the CO2 sink by continental silicate weathering, and on the impact of the magmatic degassing of CO2. We use the spatially resolved numerical model GEOCLIM ( to compute the response of the silicate weathering and atmospheric CO2 to continental drift for 22 time slices of the Phanerozoic. Regarding the CO2 released by the magmatic activity, we reconstruct several Phanerozoic histories of this flux, based on published indexes. We calculate the CO2 evolution for each degassing scenario, and accounting for the paleogeographic setting. We show that the paleogeographic setting is a main driver of the climate from 540 Ma to about the beginning of the Jurassic. Regarding the role of the magmatic degassing, the various reconstructions do not converge towards a single signal, and thus introduce large uncertainties in the calculated CO2 level over time. Nevertheless, the continental dispersion, which prevails since the Jurassic, promotes the CO2 consumption by weathering and forces atmospheric CO2 to stay low. Warm climates of the "middle" Cretaceous and early Cenozoic require enhanced CO2 degassing by magmatic activity. In summary, the Phanerozoic climate evolution can be hardly assigned to a single process, but is the result of complex and intertwined processes.

  14. Carbon sequestration in sinks. An overview of potential and costs

    International Nuclear Information System (INIS)

    Kolshus, Hans H.


    Prior to the resumed climate negotiations in Bonn in July this year, it was thought that an agreement on the unresolved crunch issues of the Kyoto Protocol was unrealistic. This was primarily due to the US withdrawal from the Kyoto Protocol, and the failure of the previous climate negotiations that stranded mainly because of disagreement on the inclusion of land use, land-use change, and forestry (LULUCF) activities. The LULUCF issue is controversial in the climate negotiations, but an agreement has now been reached. This paper explores the possible contribution of LULUCF activities in promoting greenhouse gas emissions reductions. A survey on the literature of the potential and cost of LULUCF activities is therefore central. Analysis of the recent climate negotiations is also important. It is clear that the potential for carbon sequestration is large, but there are large variations in the estimates as factors such as land availability and the rate of carbon uptake complicate the calculations. There are also variations in the costs estimates, and economic analysis of LULUCF projects are not easily compared as no standard method of analysis has emerged and come into wide use. Despite the difficulties in comparing the costs of carbon sequestration, it is clear that it is a relatively inexpensive measure. Even though the potential for carbon sequestration is large, its role in reducing emissions of greenhouse gases (GHG) is limited by the Kyoto Protocol. The recent climate negotiations in Bonn and Marrakesh have specified the modalities, rules and guidelines relating to LULUCF activities. One of the main outcomes is that Japan, Canada and Russia are allowed large inclusions of sinks in their GHG emission accounts. (author)

  15. Static vs. mobile sink: The influence of basic parameters on energy efficiency in wireless sensor networks (United States)

    Khan, Majid I.; Gansterer, Wilfried N.; Haring, Guenter


    Over the last decade a large number of routing protocols has been designed for achieving energy efficiency in data collecting wireless sensor networks. The drawbacks of using a static sink are well known. It has been argued in the literature that a mobile sink may improve the energy dissipation compared to a static one. Some authors focus on minimizing Emax, the maximum energy dissipation of any single node in the network, while others aim at minimizing Ebar, the average energy dissipation over all nodes. In our paper we take a more holistic view, considering both Emax and Ebar. The main contribution of this paper is to provide a simulation-based analysis of the energy efficiency of WSNs with static and mobile sinks. The focus is on two important configuration parameters: mobility path of the sink and duty cycling value of the nodes. On the one hand, it is well known that in the case of a mobile sink with fixed trajectory the choice of the mobility path influences energy efficiency. On the other hand, in some types of applications sensor nodes spend a rather large fraction of their total lifetime in idle mode, and therefore higher energy efficiency can be achieved by using the concept of reduced duty cycles. In particular, we quantitatively analyze the influence of duty cycling and the mobility radius of the sink as well as their interrelationship in terms of energy consumption for a well-defined model scenario. The analysis starts from general load considerations and is refined into a geometrical model. This model is validated by simulations which are more realistic in terms of duty cycling than previous work. It is illustrated that over all possible configuration scenarios in terms of duty cycle and mobility radius of the sink the energy dissipation in the WSN can vary up to a factor of nine in terms of Emax and up to a factor of 17 in terms of Ebar. It turns out that in general the choice of the duty cycle value is more important for achieving energy efficiency

  16. Thermal performance analysis of optimized hexagonal finned heat sinks in impinging air jet

    Energy Technology Data Exchange (ETDEWEB)

    Yakut, Kenan, E-mail: [Department of Mechanical Engineering, Faculty of Engineering, Atatürk University, 25100, Erzurum (Turkey); Yeşildal, Faruk, E-mail: [Department of Mechanical Engineering, Faculty of Patnos Sultan Alparslan Natural Sciences and Engineering, Ağrı İbrahim Çeçen University, 04100, Ağrı (Turkey); Karabey, Altuğ, E-mail: [Department of Machinery and Metal Technology, Erciş Vocational High School, Yüzüncü Yıl University, 65400, Van (Turkey); Yakut, Rıdvan, E-mail: [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Kafkas University, 36100, Kars (Turkey)


    In this study, thermal performance analysis of hexagonal finned heat sinks which optimized according to the experimental design and optimization method of Taguchi were investigated. Experiments of air jet impingement on heated hexagonal finned heat sinks were carried out adhering to the L{sub 18}(2{sup 1*}3{sup 6}) orthogonal array test plan. Optimum geometries were determined and named OH-1, OH-2. Enhancement efficiency with the first law of thermodynamics was analyzed for optimized heat sinks with 100, 150, 200 mm heights of hexagonal fin. Nusselt correlations were found out and variations of enhancement efficiency with Reynolds number presented in η–Re graphics.

  17. Static vs. mobile sink: The influence of basic parameters on energy efficiency in wireless sensor networks. (United States)

    Khan, Majid I; Gansterer, Wilfried N; Haring, Guenter


    Over the last decade a large number of routing protocols has been designed for achieving energy efficiency in data collecting wireless sensor networks. The drawbacks of using a static sink are well known. It has been argued in the literature that a mobile sink may improve the energy dissipation compared to a static one. Some authors focus on minimizing Emax , the maximum energy dissipation of any single node in the network, while others aim at minimizing Ebar , the average energy dissipation over all nodes. In our paper we take a more holistic view, considering both Emax and Ebar . The main contribution of this paper is to provide a simulation-based analysis of the energy efficiency of WSNs with static and mobile sinks. The focus is on two important configuration parameters: mobility path of the sink and duty cycling value of the nodes. On the one hand, it is well known that in the case of a mobile sink with fixed trajectory the choice of the mobility path influences energy efficiency. On the other hand, in some types of applications sensor nodes spend a rather large fraction of their total lifetime in idle mode, and therefore higher energy efficiency can be achieved by using the concept of reduced duty cycles. In particular, we quantitatively analyze the influence of duty cycling and the mobility radius of the sink as well as their interrelationship in terms of energy consumption for a well-defined model scenario. The analysis starts from general load considerations and is refined into a geometrical model. This model is validated by simulations which are more realistic in terms of duty cycling than previous work. It is illustrated that over all possible configuration scenarios in terms of duty cycle and mobility radius of the sink the energy dissipation in the WSN can vary up to a factor of nine in terms of Emax and up to a factor of 17 in terms of Ebar. It turns out that in general the choice of the duty cycle value is more important for achieving energy

  18. Transient cooling of electronics using phase change material (PCM)-based heat sinks

    International Nuclear Information System (INIS)

    Kandasamy, Ravi; Wang Xiangqi; Mujumdar, Arun S.


    Use of a phase change material (PCM)-based heat sink in transient thermal management of plastic quad flat package (QFP) electronic devices was investigated experimentally and numerically. Results show that increased power inputs enhance the melting rate as well as the thermal performance of the PCM-based heat sinks until the PCM is fully melted. A three-dimensional computational fluid dynamics model was proposed to simulate the problem and demonstrated good agreement with experimental data. Results indicate the potential for PCM-based heat sinks for use in intermittent-use devices

  19. High-voltage integrated linear regulator with current sinking capabilities for portable ultrasound scanners

    DEFF Research Database (Denmark)

    Pausas, Guifre Vendrell; Llimos Muntal, Pere; Jørgensen, Ivan Harald Holger


    This paper presents a high-voltage integrated regulator capable of sinking current for driving pulse-triggered level shifters in drivers for ultrasound applications. The regulator utilizes a new topology with a feedback loop and a current sinking circuit to satisfy the requirements of the portable...... ultrasound scanner: a great driving strength in the scanner's transducer and a low undershoot voltage in the output node. The design regulates an output voltage of 45 V from an input voltage of 50 V, and it can sink currents up to 100 mA using no external components with only 340 mV of undershoot voltage...

  20. Faster heme loss from hemoglobin E than HbS, in acidic pH: Effect ...

    Indian Academy of Sciences (India)

    We report studies on loss of heme at or below pH 3.0 from two clinically important hemoglobin variants, HbE and HbS, in the presence and absence of phopholipid membranes. The kinetics of heme loss has been studied at pH 3.0 to simulate the same at a faster rate than at physiological pH, for spectroscopic investigation.

  1. Ballast minerals and the sinking carbon flux in the ocean: carbon-specific respiration rates and sinking velocity of marine snow aggregates

    Directory of Open Access Journals (Sweden)

    M. H. Iversen


    Full Text Available Recent observations have shown that fluxes of ballast minerals (calcium carbonate, opal, and lithogenic material and organic carbon fluxes are closely correlated in the bathypelagic zones of the ocean. Hence it has been hypothesized that incorporation of biogenic minerals within marine aggregates could either protect the organic matter from decomposition and/or increase the sinking velocity via ballasting of the aggregates. Here we present the first combined data on size, sinking velocity, carbon-specific respiration rate, and composition measured directly in three aggregate types; Emiliania huxleyi aggregates (carbonate ballasted, Skeletonema costatum aggregates (opal ballasted, and aggregates made from a mix of both E. huxleyi and S. costatum (carbonate and opal ballasted. Overall average carbon-specific respiration rate was ~0.13 d−1 and did not vary with aggregate type and size. Ballasting from carbonate resulted in 2- to 2.5-fold higher sinking velocities than those of aggregates ballasted by opal. We compiled literature data on carbon-specific respiration rate and sinking velocity measured in aggregates of different composition and sources. Compiled carbon-specific respiration rates (including this study vary between 0.08 d−1 and 0.20 d−1. Sinking velocity increases with increasing aggregate size within homogeneous sources of aggregates. When compared across different particle and aggregate sources, however, sinking velocity appeared to be independent of particle or aggregate size. The carbon-specific respiration rate per meter settled varied between 0.0002 m−1 and 0.0030 m−1, and decreased with increasing aggregate size. It was lower for calcite ballasted aggregates as compared to that of similar sized opal ballasted aggregates.

  2. High resolution near on-axis digital holography using constrained optimization approach with faster convergence (United States)

    Pandiyan, Vimal Prabhu; Khare, Kedar; John, Renu


    A constrained optimization approach with faster convergence is proposed to recover the complex object field from a near on-axis digital holography (DH). We subtract the DC from the hologram after recording the object beam and reference beam intensities separately. The DC-subtracted hologram is used to recover the complex object information using a constrained optimization approach with faster convergence. The recovered complex object field is back propagated to the image plane using the Fresnel back-propagation method. The results reported in this approach provide high-resolution images compared with the conventional Fourier filtering approach and is 25% faster than the previously reported constrained optimization approach due to the subtraction of two DC terms in the cost function. We report this approach in DH and digital holographic microscopy using the U.S. Air Force resolution target as the object to retrieve the high-resolution image without DC and twin image interference. We also demonstrate the high potential of this technique in transparent microelectrode patterned on indium tin oxide-coated glass, by reconstructing a high-resolution quantitative phase microscope image. We also demonstrate this technique by imaging yeast cells.

  3. Ratosa playa lake in southern Spain. Karst pan or compound sink? (United States)

    Rodríguez-Rodríguez, Miguel; Martos-Rosillo, Sergio; Pedrera, Antonio; Benavente-Herrera, José


    In Andalusia (Spain), there are more than 45 semiarid playa lakes protected as natural reserves and related to karstic outcrops. Some of them are located over regional karstic aquifers and have internal drainage networks with sporadic surface outlets, such as sinkholes (compound sinks), but the majority of such playas have no internal drainage systems, so the only water output is evaporation (karst pans). Karst pans are perched and disconnected from the groundwater system. The fact that the Ratosa playa lake is partially located over a karstic Sierra, as well as other hydromorphological observations, it is suggested that the system could be of a compound type, but a detailed hydrogeological analysis showed that the playa is disconnected from the aquifer, so it is in fact a karst pan. Once the hydrological functioning had been established, a monthly water balance for a 10-year period (1998-2008), enabled us to reproduce the evolution of the water level of the playa lake. Estimations of runoff were carried out by a soil water estimate for a water holding capacity in the soil of 191 mm. Results show a good correlation (>90%) after calibration with the time series of water level in the lake for the same period confirming geological observations. Our results highlight that this water body is extremely vulnerable to hydrological alterations of its watershed caused by human activities, particularly those related to land-use change for agriculture. For this reason, we propose a new protection zone, based on hydrological knowledge, instead of the present Peripheral Area of Protection.

  4. Carbon sequestration capacity and secondary succession in a dry environment (United States)

    Estruch, Carme; Lozano, Yudi M.; Armas, Cristina; Pugnaire, Francisco I.


    Human activities often alter natural plant communities which, after disturbance, undergo a process of secondary succession with important changes in C dynamics. In arid environments this process is very slow, and its links with C cycling are little known. We addressed changes in C balance along a chronosequence of land abandonment in a semiarid environment and assessed the consequences of secondary succession on C sequestration capacity at community scale. We used a closed-chamber method to estimate the daytime contribution of whole-plants and bare soil to whole-community C exchange. Plant community composition and cover strongly affected C balance across the chronosequence. Overall, whole-community C exchange shifted from C source to C sink with succession. However, only after 63 years of agriculture abandonment the system did recover its natural C sequestration capacity. Thus, the capacity of semiarid ecosystems to recover native plant communities after anthropogenic disturbance may contribute to decrease C emissions in the long term.


    Directory of Open Access Journals (Sweden)



    The efficacy of available backup and ultimate heat sinks, available in a CANDU 6 reactor, in mitigating the consequences of a prolonged station blackout scenario was analysed using the MAAP4-CANDU code. The analysis indicated that the steam generator secondary side water inventory is the most effective heat sink during the accident. Additional heat sinks such as the primary coolant, moderator, calandria vault water and end shield water are also able to remove decay heat; however, a gradually increasing mismatch between heat generation and heat removal occurs over the course of the postulated event. This mismatch is equivalent to an additional water inventory estimated to be 350,000 kg at the time of calandria vessel failure. In the Enhanced CANDU 6 reactor ∼2,040,000 kg of water in the reserve water tank is available for prolonged emergencies requiring heat sinks.

  6. Diamond Microchannel Heat Sink Designs For High Heat Flux Thermal Control

    National Research Council Canada - National Science Library

    Corbin, Michael


    .... Many investigators have suggested the use of diamond heat spreaders to reduce flux levels at or near to its source, and some have suggested that diamond microchannel heat sinks ultimately may play...

  7. CTE-Matched, Liquid-Cooled, High Thermal Conductivity Heat Sink, Phase I (United States)

    National Aeronautics and Space Administration — We propose the development of a CTE-matched, liquid-cooled, high thermal conductivity heat sink for use in spacecraft thermal management applications. The material...

  8. Experimental and Transient Thermal Analysis of Heat Sink Fin for CPU processor for better performance (United States)

    Ravikumar, S.; Subash Chandra, Parisaboina; Harish, Remella; Sivaji, Tallapaneni


    The advancement of the digital computer and its utilization day by day is rapidly increasing. But the reliability of electronic components is critically affected by the temperature at which the junction operates. The designers are forced to shorten the overall system dimensions, in extracting the heat and controlling the temperature which focus the studies of electronic cooling. In this project Thermal analysis is carried out with a commercial package provided by ANSYS. The geometric variables and design of heat sink for improving the thermal performance is experimented. This project utilizes thermal analysis to identify a cooling solution for a desktop computer, which uses a 5 W CPU. The design is able to cool the chassis with heat sink joined to the CPU is adequate to cool the whole system. This work considers the circular cylindrical pin fins and rectangular plate heat sink fins design with aluminium base plate and the control of CPU heat sink processes.

  9. Hormonal and metabolic regulation of tomato fruit sink activity and yield under salinity

    Czech Academy of Sciences Publication Activity Database

    Albacete, A.; Cantero-Navarro, E.; Balibrea, M. E.; Grosskinsky, D. K.; de la Cruz Gonzalez, M.; Martínez-Andújar, C.; Smigocki, A. C.; Roitsch, Thomas; Pérez-Alfocea, F.


    Roč. 65, č. 20 (2014), s. 6081-6095 ISSN 0022-0957 Institutional support: RVO:67179843 Keywords : Cell wall invertase * cytokinins * fruit * salinity * sink activity * tomato Subject RIV: EF - Botanics Impact factor: 5.526, year: 2014

  10. A molecular-genetic approach to studying source-sink interactions in Arabidopsis thalian. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, S. I.


    This is a final report describing the results of the research funded by the DOE Energy Biosciences Program grant entitled ''A Molecular-Genetic Approach to Studying Source-Sink Interactions in Arabidiopsis thaliana''.

  11. Inventory of U.S. greenhouse gas emissions and sinks: 1990-2008 (United States)


    An emissions inventory that identifies and quantifies a country's primary anthropogenic sources and sinks of greenhouse gases is essential for addressing climate change. This inventory adheres to both 1) a comprehensive and detailed set of methodolog...

  12. 78 FR 21596 - Drawn Stainless Steel Sinks From the People's Republic of China: Countervailing Duty Order (United States)


    ... single or multiple drawn bowls, with or without drain boards, whether finished or unfinished, regardless... steel, and then welding and finishing the vertical corners to form the bowls. Stainless steel sinks with...

  13. Forced convective performance of perforated circular pin-fin heat sinks (United States)

    Wen, Mao-Yu; Yeh, Cheng-Hsiung


    This study examines heat transfer performance under forced convection for two different types (Type A and Type B) of pin-fin heat sinks with and without a hollow in the heated base. The effects of the Reynolds number, heights of the fin and base plate, finning factor, heat sink porosity and perforated base plate on the heat-transfer coefficient, fin effectiveness and pressure drop were investigated and evaluated. The present study strongly suggests the use of a small hollow [( D h / D b ) plate of the pin-fin heat sink. In order to obtain insight into the fluid flow phenomena, flow visualization was also made to observe the detailed fluid flow characteristics of the present pin-fin heat sinks.

  14. Comparison of various sink strengths for analyzing radiation creep, growth and swelling

    International Nuclear Information System (INIS)

    Nichols, F.A.; Liu, Y.Y.


    The essential physics involved in the reaction-rate-theory analysis of radiation effects at temperatures where both vacancies and self interstitials are mobile is contained in the expressions used for the strengths of distributed point-defect sinks such as dislocations, cavities and grain boundaries. These sink strengths have been obtained by various authors in distinctly different ways, thus giving rise to some possible confusion in comparing the various results. This is even more true with respect to the effect of interaction fields on these sink strengths and the so-called bias factors or sink efficiencies have been defined in entirely different ways, thus rendering quantitative comparisons difficult. We present here a comparison of several procedures in the literature, and attempt to make reasonable quantitative comparisons

  15. Reconstructing source-sink dynamics in a population with a pelagic dispersal phase.

    Directory of Open Access Journals (Sweden)

    Kun Chen

    Full Text Available For many organisms, the reconstruction of source-sink dynamics is hampered by limited knowledge of the spatial assemblage of either the source or sink components or lack of information on the strength of the linkage for any source-sink pair. In the case of marine species with a pelagic dispersal phase, these problems may be mitigated through the use of particle drift simulations based on an ocean circulation model. However, when simulated particle trajectories do not intersect sampling sites, the corroboration of model drift simulations with field data is hampered. Here, we apply a new statistical approach for reconstructing source-sink dynamics that overcomes the aforementioned problems. Our research is motivated by the need for understanding observed changes in jellyfish distributions in the eastern Bering Sea since 1990. By contrasting the source-sink dynamics reconstructed with data from the pre-1990 period with that from the post-1990 period, it appears that changes in jellyfish distribution resulted from the combined effects of higher jellyfish productivity and longer dispersal of jellyfish resulting from a shift in the ocean circulation starting in 1991. A sensitivity analysis suggests that the source-sink reconstruction is robust to typical systematic and random errors in the ocean circulation model driving the particle drift simulations. The jellyfish analysis illustrates that new insights can be gained by studying structural changes in source-sink dynamics. The proposed approach is applicable for the spatial source-sink reconstruction of other species and even abiotic processes, such as sediment transport.

  16. Computer-aided Micro-EDM die-sinking tool design optimisation


    SURLERAUX, Anthony; LEPERT, Romain; Pernot, Jean-Philippe; Bigot, Samuel


    International audience; This paper describes a new efficient method for computer aided optimisations of micro EDM die sinking tools, which can be used for design optimisation and performance verification in the digital domain. This would facilitate the integration and re-configurability of the micro EDM die sinking process in high value products manufacturing chains. An EDM simulation tool which makes use of voxels embedded in a voxel octree to represent the geometries is introduced and its a...

  17. The influence of heat sink temperature on the seasonal efficiency of shallow geothermal heat pumps (United States)

    Pełka, Grzegorz; Luboń, Wojciech; Sowiżdżał, Anna; Malik, Daniel


    Geothermal heat pumps, also known as ground source heat pumps (GSHP), are the most efficient heating and cooling technology utilized nowadays. In the AGH-UST Educational and Research Laboratory of Renewable Energy Sources and Energy Saving in Miękinia, shallow geothermal heat is utilized for heating. In the article, the seasonal efficiency of two geothermal heat pump systems are described during the 2014/2015 heating season, defined as the period between 1st October 2014 and 30th April 2015. The first system has 10.9 kW heating capacity (according to European Standard EN 14511 B0W35) and extracts heat from three vertical geothermal loops at a depth of 80m each. During the heating season, tests warmed up the buffer to 40°C. The second system has a 17.03 kW heating capacity and extracts heat from three vertical geothermal loops at a depth of 100 m each, and the temperature of the buffer was 50°C. During the entire heating season, the water temperatures of the buffers was constant. Seasonal performance factors were calculated, defined as the quotient of heat delivered by a heat pump to the system and the sum of electricity consumed by the compressor, source pump, sink pump and controller of heat pumps. The measurements and calculations give the following results: - The first system was supplied with 13 857 kWh/a of heat and consumed 3 388 kWh/a electricity. The SPF was 4.09 and the average temperature of outlet water from heat pump was 40.8°C, and the average temperature of brine flows into the evaporator was 3.7 °C; - The second system was supplied with 12 545 kWh/a of heat and consumed 3 874 kWh/a electricity. The SPF was 3.24 and the average temperature of outlet water from heat pump was 51.6°C, and the average temperature of brine flows into the evaporator was 5.3°C. To summarize, the data shown above presents the real SPF of the two systems. It will be significant in helping to predict the SPF of objects which will be equipped with ground source heat pumps.

  18. Assessing institutional capacities to adapt to climate change - integrating psychological dimensions in the Adaptive Capacity Wheel (United States)

    Grothmann, T.; Grecksch, K.; Winges, M.; Siebenhüner, B.


    Several case studies show that "soft social factors" (e.g. institutions, perceptions, social capital) strongly affect social capacities to adapt to climate change. Many soft social factors can probably be changed faster than "hard social factors" (e.g. economic and technological development) and are therefore particularly important for building social capacities. However, there are almost no methodologies for the systematic assessment of soft social factors. Gupta et al. (2010) have developed the Adaptive Capacity Wheel (ACW) for assessing the adaptive capacity of institutions. The ACW differentiates 22 criteria to assess six dimensions: variety, learning capacity, room for autonomous change, leadership, availability of resources, fair governance. To include important psychological factors we extended the ACW by two dimensions: "adaptation motivation" refers to actors' motivation to realise, support and/or promote adaptation to climate. "Adaptation belief" refers to actors' perceptions of realisability and effectiveness of adaptation measures. We applied the extended ACW to assess adaptive capacities of four sectors - water management, flood/coastal protection, civil protection and regional planning - in North Western Germany. The assessments of adaptation motivation and belief provided a clear added value. The results also revealed some methodological problems in applying the ACW (e.g. overlap of dimensions), for which we propose methodological solutions.

  19. A review on heat sink for thermo-electric power generation: Classifications and parameters affecting performance

    International Nuclear Information System (INIS)

    Elghool, Ali; Basrawi, Firdaus; Ibrahim, Thamir Khalil; Habib, Khairul; Ibrahim, Hassan; Idris, Daing Mohamad Nafiz Daing


    Highlights: • Coupling a thermoelectric power generation (TEG) to a heat sink is presented. • Review the classifications and parameters affecting performance of the TEG with heat sink. • Discuss different mathematical models of the heat sinks. • The passive heat sinks are most appropriate because of the inherent efficiency of TEG. • Medium temperature range below 300 °C is found to be most suitable for HPHS. - Abstract: In recent years, there have been growing interests in key areas related to global warming resulting from environmental emissions, and the diminishing sources of fossil fuel. The increased interest has led to significant research efforts towards finding novel technologies in clean energy production. Consequently, the merits of a thermo-electric generator (TEG) have promised a revival of alternative means of producing green energy. It is, however, impractical to account for the cost of thermal energy input to the TEG which is in the form of final waste heat. This is because the technology presents critical limitations in determining its cost efficiency nor its economic disadvantages. This paper reviews the principles of thermo-electric power production, as well the materials use, performance achieved, and application areas. The paper also takes a particular deliberation on TEG heat sinks geometries and categories. The review emphasizes more on the TEG performance while considering a number of heat sink parameters related to its performance.

  20. A Novel Heat Sink Design and Prototyping for LED Desk Lamps

    Directory of Open Access Journals (Sweden)

    Li-Ming Chu


    Full Text Available Light-emitting diode (LED is a modern lighting device. If the heat dissipating mechanism of LED desk lamp is not well designed, the induced high temperature will cause the reduction of illumination and life time of lamp. Therefore, the heat sink design becomes a key technology for LED lighting device. This study developed a methodology to design and analyze a heat sink for LED cooling. Four different types of heat sinks with fins in longitudinal or transverse directions and with or without vents on the base plate were compared. By using the CFD software FLUENT, heat flux and temperature around the heat sink were analyzed, and the surface temperature distribution was also investigated. The simulation outcomes were compared with experiments results to verify analysis accuracy. The comparisons show only slight differences, and the deviations were less than 4.0%. For cooling LED desk lamp, the design of using 12 vents on both sides of heat sink through natural convection to create the chimney effect was adopted; consequently, the temperature dropped 5°C in average. This design can also reduce the material of heat sink, LED lamp weight, and production cost.

  1. Sinking rates of microplastics and potential implications of their alteration by physical, biological, and chemical factors. (United States)

    Kowalski, Nicole; Reichardt, Aurelia M; Waniek, Joanna J


    To follow the pathways of microplastics in aquatic environments, profound knowledge about the behaviour of microplastics is necessary. Therefore, sinking experiments were conducted with diverse polymer particles using fluids with different salinity. Particles ranged from 0.3 and 3.6mm with sinking rates between 6 and 91×10(-3)ms(-1). The sinking velocity was not solely related to particle density, size and fluid density but also to the particles shape leading to considerable deviation from calculated theoretical values. Thus, experimental studies are indispensable to get basic knowledge about the sinking behaviour and to gain representative datasets for model approaches estimating the distribution of microplastics in aquatic systems. The sinking behaviour may be altered considerably by weathering and biofouling demanding further studies with aged and fouled plastic particles. Furthermore, assumptions are made about the influence of sinking fouled microplastics on the marine carbon pump by transferring organic carbon to deeper water depths. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Habitat-specific demography: evidence for source-sink population structure in a mammal, the pika. (United States)

    Kreuzer, M P; Huntly, N J


    Theory suggests that populations may persist in sink habitats that cannot support replacement-level birth rates. Although it is commonly believed that organisms that can actively select habitat should rarely occur in sinks, the frequency of use of sinks in free-ranging species is not well-documented. We found that a population of American pikas ( Ochotona princeps, Lagomorpha) inhabiting distinct alpine habitats (meadow and snowbed) in Wyoming, USA, had habitat-specific demographic rates that produced a source-sink population structure. Population size increased in both habitats in summer and declined in both habitats in winter, with populations in snowbeds increasing more during summer and decreasing more over winter. Birth rates were consistently higher in meadows and populations in meadows had a consistently higher finite rate of increase (lambda, from life tables) than did those in snowbeds, for which lambda was far below that needed for replacement. Patterns of immigration, population structure, and temporal variation in population size were as expected if meadows were functional sources and snowbeds functional sinks. Patterns of snowmelt differed between habitats, predicted the critical difference in birth rates between habitats, and are a likely primary cause of the differences in habitat-specific birth rates that we observed. This study provides a clear example of source-sink population structure for a mammal.

  3. Infrared evaluation of the heat-sink bipolar diathermy dissection technique. (United States)

    Allan, J; Dusseldorp, J; Rabey, N G; Malata, C M; Goltsman, D; Phoon, A F


    The use of the bipolar diathermy dissection technique is widespread amongst surgeons performing flap perforator dissection and microvascular surgery. The 'heat-sink' modification uses a DeBakey forcep as a heat sinking interposition between the bipolar tip and the main (vascular or flap) pedicle aiming to protect it from the thermal effects of the bipolar diathermy. This study examines the thermal effects of bipolar cautery upon the microvasculature and investigates the efficacy of heat sinking as a thermally protective technique in microsurgical dissection. A chicken thigh microsurgical training model was used to examine the effects of bipolar cautery. The effects of bipolar were examined using high definition, real-time infrared thermographic imaging (FLIR Systems) and temperature quantitatively assessed at various distances away from the point of bipolar cautery. Comparison was made using the heat sink technique to determine if it conferred a thermoprotective effect compared to the standard technique without heat sink. Using paired t-test analysis (SPSS) the heat sink modification of the bipolar dissection technique was found to have a highly statistically significant effect (P technique to prevent thermal spread and limit potential coagulopathic changes. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  4. Paired-pulse depression of excitatory postsynaptic current sinks in hippocampal CA1 in vivo. (United States)

    Leung, L Stan; Peloquin, Pascal; Canning, Kevin J


    Paired-pulse depression (PPD), a short-term neural plasticity, was studied in hippocampal CA1 of urethane-anesthetized rats in vivo, using field potential recordings and current source density analysis. PPD was robust when an ipsilateral CA3 (iCA3) conditioning pulse of moderate stimulus intensity was followed 30-200 ms later by a contralateral CA3 (cCA3) test pulse; the ratio of the conditioned (C) to the nonconditioned (NC) response, as measured by the peak excitatory sink at the apical dendrites, ranged from 0.6 to 0.8. An alveus conditioning pulse evoked a large antidromic population spike in CA1 and a modest depression of the CA3-evoked excitatory sink (C/NC ratio of approximately 0.85). High-intensity paired pulses, both delivered to iCA3, also showed PPD of the proximal excitatory sinks; however, paired-pulse facilitation of the dendritic sinks was found at the mid-apical dendrites, >250 microm from the soma. Local injection of GABA(A) antagonist picrotoxin or bicuculline increased the C/NC ratio at IPIs of sinks was caused by mainly feedforward and some feedback inhibition at the apical dendrites. GABA(A)-mediated postsynaptic inhibition dominated at early latencies, while GABA(B)-mediated inhibition prevailed at long latencies, probably at both presynaptic and postsynaptic sites. PPD of the excitatory sinks provides a measure of population dendritic inhibition in vivo.

  5. Ecological Meaning and Consideration of Economic Forest Carbon Sinks in China----Take Yan-Shan Chestnut for Example (United States)

    Wang, Z.; Li, H.; Zhang, W. W.; Liu, S. R.

    Along with our country scientific researchers' study on native forest carbon sinks as well as the summary of the increasing amount of China's forest carbon, With the deepening of our scientists on the study of the national forest carbon sinks, forest carbon sinks has become a favorable support for climate diplomacy. Currently, a lot of work has focused on the carbon cycle, the level of carbon sinks of forest ecosystems, but the characteristics of economic forest carbon sinks are in a blank state. Beijing chestnut is one of the national food strategic security stockpiles, and estimate the potential of economic forest carbon sinks has important scientific significance to the establishment of carbon sink function area, and expansion of sustainable economic and social development of response measures.

  6. Capacity Statement for Railways

    DEFF Research Database (Denmark)

    Landex, Alex


    The subject “Railway capacity” is a combination of the capacity consumption and how the capacity is utilized. The capacity utilization of railways can be divided into 4 core elements: The number of trains; the average speed; the heterogeneity of the operation; and the stability. This article desc...... trains. This is due to network effects in the railway system and due to the fact that more trains results in lower punctuality....

  7. Carbon storage in old-growth forests of the Mid-Atlantic: toward better understanding the eastern forest carbon sink. (United States)

    McGarvey, Jennifer C; Thompson, Jonathan R; Epstein, Howard E; Shugart, Herman H


    Few old-growth stands remain in the matrix of secondary forests that dominates the eastern North American landscape. These remnant stands offer insight on the potential carbon (C) storage capacity of now-recovering secondary forests. We surveyed the remaining old-growth forests on sites characteristic of the general Mid-Atlantic United States and estimated the size of multiple components of forest C storage. Within and between old-growth stands, variability in C density is high and related to overstory tree species composition. The sites contain 219 ± 46 Mg C/ha (mean ± SD), including live and dead aboveground biomass, leaf litter, and the soil O horizon, with over 20% stored in downed wood and snags. Stands dominated by tulip poplar (Liriodendron tulipifera) store the most live biomass, while the mixed oak (Quercus spp.) stands overall store more dead wood. Total C density is 30% higher (154 Mg C/ha), and dead wood C density is 1800% higher (46 Mg C/ha) in the old-growth forests than in the surrounding younger forests (120 and 5 Mg C/ha, respectively). The high density of dead wood in old growth relative to secondary forests reflects a stark difference in historical land use and, possibly, the legacy of the local disturbance (e.g., disease) history. Our results demonstrate the potential for dead wood to maintain the sink capacity of secondary forests for many decades to come.

  8. The making of giant pumpkins: how selective breeding changed the phloem of Cucurbita maxima from source to sink. (United States)

    Savage, Jessica A; Haines, Dustin F; Holbrook, N Michele


    Despite the success of breeding programmes focused on increasing fruit size, relatively little is known about the anatomical and physiological changes required to increase reproductive allocation. To address this gap in knowledge, we compared fruit/ovary anatomy, vascular structure and phloem transport of two varieties of giant pumpkins, and their smaller fruited progenitor under controlled environmental conditions. We also modelled carbon transport into the fruit of competitively grown plants using data collected in the field. There was no evidence that changes in leaf area or photosynthetic capacity impacted fruit size. Instead, giant varieties differed in their ovary morphology and contained more phloem on a cross-sectional area basis in their petioles and pedicels than the ancestral variety. These results suggest that sink activity is important in determining fruit size and that giant pumpkins have an enhanced capacity to transport carbon. The strong connection observed between carbon fixation, phloem structure and fruit growth in field-grown plants indicates that breeding for large fruit has led to changes throughout the carbon transport system that could have important implications for how we think about phloem transport velocity and carbon allocation. © 2014 John Wiley & Sons Ltd.

  9. The French capacity mechanism

    International Nuclear Information System (INIS)


    The French capacity mechanism has been design to ensure security of supply in the context of the energy transition. This energy transition challenges the electricity market design with several features: peak load growth, the development of renewables, demand response,... To ensure security of supply in this context, a capacity mechanism is being implemented in France. It is a market wide capacity obligation on electricity suppliers, based on market principles. Suppliers are responsible for forecasting their obligation, which corresponds to their contribution to winter peak load, and must procure enough capacity certificates to meet their obligations. Capacity certificates are granted to capacities through a certification process, which assesses their contribution to security of supply on the basis of availability commitments. This certification process is technology neutral and performance based, associated with controls and penalties in case of non compliance. Demand Side is fully integrated in the market, either through the reduction of suppliers' capacity obligation or direct participation after certification. In addition to the expected benefits in terms of security of supply, the French capacity market will foster the development of demand response. The participation of foreign capacities will require adaptations which are scheduled in a road-map, and could pave the way for further European integration of energy policies. (authors)

  10. The Faster, Better, Cheaper Approach to Space Missions: An Engineering Management Assessment (United States)

    Hamaker, Joseph W.


    NASA was chartered as an independent civilian space agency in 1958 following the Soviet Union's dramatic launch of the Sputnik 1 (1957). In his state of the union address in May of 1961, President Kennedy issued to the fledging organization his famous challenge for a manned lunar mission by the end of the decade. The Mercury, Gemini and Apollo programs that followed put the utmost value on high quality, low risk (as low as possible within the context of space flight), quick results, all with little regard for cost. These circumstances essentially melded NASAs culture as an organization capable of great technological achievement but at extremely high cost. The Space Shuttle project, the next major agency endeavor, was put under severe annual budget constraints in the 1970's. NASAs response was to hold to the high quality standards, low risk and annual cost and let schedule suffer. The result was a significant delay in the introduction of the Shuttle as well as overall total cost growth. By the early 1990's, because NASA's budget was declining, the number of projects was also declining. Holding the same cost and schedule productivity levels as before was essentially causing NASA to price itself out of business. In 1992, the helm of NASA was turned over to a new Administrator. Dan Goldin's mantra was "faster, better, cheaper" and his enthusiasm and determination to change the NASA culture was not to be ignored. This research paper documents the various implementations of "faster, better, cheaper" that have been attempted, analyzes their impact and compares the cost performance of these new projects to previous NASA benchmarks. Fundamentally, many elements of "faster, better, cheaper" are found to be working well, especially on smaller projects. Some of the initiatives are found to apply only to smaller or experimental projects however, so that extrapolation to "flagship" projects may be problematic.

  11. Faster Smith-Waterman database searches with inter-sequence SIMD parallelisation

    Directory of Open Access Journals (Sweden)

    Rognes Torbjørn


    Full Text Available Abstract Background The Smith-Waterman algorithm for local sequence alignment is more sensitive than heuristic methods for database searching, but also more time-consuming. The fastest approach to parallelisation with SIMD technology has previously been described by Farrar in 2007. The aim of this study was to explore whether further speed could be gained by other approaches to parallelisation. Results A faster approach and implementation is described and benchmarked. In the new tool SWIPE, residues from sixteen different database sequences are compared in parallel to one query residue. Using a 375 residue query sequence a speed of 106 billion cell updates per second (GCUPS was achieved on a dual Intel Xeon X5650 six-core processor system, which is over six times more rapid than software based on Farrar's 'striped' approach. SWIPE was about 2.5 times faster when the programs used only a single thread. For shorter queries, the increase in speed was larger. SWIPE was about twice as fast as BLAST when using the BLOSUM50 score matrix, while BLAST was about twice as fast as SWIPE for the BLOSUM62 matrix. The software is designed for 64 bit Linux on processors with SSSE3. Source code is available from under the GNU Affero General Public License. Conclusions Efficient parallelisation using SIMD on standard hardware makes it possible to run Smith-Waterman database searches more than six times faster than before. The approach described here could significantly widen the potential application of Smith-Waterman searches. Other applications that require optimal local alignment scores could also benefit from improved performance.

  12. Faster self-paced rate of drinking for alcohol mixed with energy drinks versus alcohol alone. (United States)

    Marczinski, Cecile A; Fillmore, Mark T; Maloney, Sarah F; Stamates, Amy L


    The consumption of alcohol mixed with energy drinks (AmED) has been associated with higher rates of binge drinking and impaired driving when compared with alcohol alone. However, it remains unclear why the risks of use of AmED are heightened compared with alcohol alone even when the doses of alcohol consumed are similar. Therefore, the purpose of this laboratory study was to investigate if the rate of self-paced beverage consumption was faster for a dose of AmED versus alcohol alone using a double-blind, within-subjects, placebo-controlled study design. Participants (n = 16) of equal gender who were social drinkers attended 4 separate test sessions that involved consumption of alcohol (1.97 ml/kg vodka) and energy drinks, alone and in combination. On each test day, the dose assigned was divided into 10 cups. Participants were informed that they would have a 2-h period to consume the 10 drinks. After the self-paced drinking period, participants completed a cued go/no-go reaction time (RT) task and subjective ratings of stimulation and sedation. The results indicated that participants consumed the AmED dose significantly faster (by ∼16 min) than the alcohol dose. For the performance task, participants' mean RTs were slower in the alcohol conditions and faster in the energy-drink conditions. In conclusion, alcohol consumers should be made aware that rapid drinking might occur for AmED beverages, thus heightening alcohol-related safety risks. The fast rate of drinking may be related to the generalized speeding of responses after energy-drink consumption. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  13. A faster pedigree-based generalized multifactor dimensionality reduction method for detecting gene-gene interactions. (United States)

    Chen, Guo-Bo; Zhu, Jun; Lou, Xiang-Yang


    We proposed a faster pedigree-based generalized multifactor dimensionality reduction algorithm, called PedG-MDR II (PII), to detect gene-gene interactions underlying complex traits. Inherited from our previous framework of PedGMDR (PI), PII can handle both dichotomous and continuous traits in pedigree-based designs and allows for covariate adjustment. Compared with PI, this faster version can theoretically halve the computing burden and memory requirement. To evaluate the performance of PII, we performed comprehensive simulations across a wide variety of experimental scenarios, in which we considered two study designs, discordant sib pairs and mixed families of varying size, and, for each study design, we considered five common factors that may potentially affect statistical power: minor allele frequency, missing rate of parental genotypes, covariate effect, gene-gene interaction, and scheme to adjust phenotypic outcomes. Simulations showed that PII gave well controlled type I error rates against population admixture. Under a total of 4,096 scenarios simulated, PII, in general, had a higher average power than PI for both dichotomous and continuous traits, and the advantage was more pronounced for continuous traits. PII also appeared to be less sensitive than PI to changes in the other four factors than the magnitude of genetic effects considered in this study. Applied to the Mid-South Tobacco Family study, PII detected a significant interaction with a p value of 5.4 × 10(-5) between two taster receptor genes, TAS2R16 and TAS2R38, responsible for nicotine dependence. In conclusion, PII is a faster supplementary version of our previous PI for detecting multifactor interactions.

  14. Faster native vowel discrimination learning in musicians is mediated by an optimization of mnemonic functions. (United States)

    Elmer, Stefan; Greber, Marielle; Pushparaj, Arethy; Kühnis, Jürg; Jäncke, Lutz


    The ability to discriminate phonemes varying in spectral and temporal attributes constitutes one of the most basic intrinsic elements underlying language learning mechanisms. Since previous work has consistently shown that professional musicians are characterized by perceptual and cognitive advantages in a variety of language-related tasks, and since vowels can be considered musical sounds within the domain of speech, here we investigated the behavioral and electrophysiological correlates of native vowel discrimination learning in a sample of professional musicians and non-musicians. We evaluated the contribution of both the neurophysiological underpinnings of perceptual (i.e., N1/P2 complex) and mnemonic functions (i.e., N400 and P600 responses) while the participants were instructed to judge whether pairs of native consonant-vowel (CV) syllables manipulated in the first formant transition of the vowel (i.e., from /tu/ to /to/) were identical or not. Results clearly demonstrated faster learning in musicians, compared to non-musicians, as reflected by shorter reaction times and higher accuracy. Most notably, in terms of morphology, time course, and voltage strength, this steeper learning curve was accompanied by distinctive N400 and P600 manifestations between the two groups. In contrast, we did not reveal any group differences during the early stages of auditory processing (i.e., N1/P2 complex), suggesting that faster learning was mediated by an optimization of mnemonic but not perceptual functions. Based on a clear taxonomy of the mnemonic functions involved in the task, results are interpreted as pointing to a relationship between faster learning mechanisms in musicians and an optimization of echoic (i.e., N400 component) and working memory (i.e., P600 component) functions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Computing with a single qubit faster than the computation quantum speed limit (United States)

    Sinitsyn, Nikolai A.


    The possibility to save and process information in fundamentally indistinguishable states is the quantum mechanical resource that is not encountered in classical computing. I demonstrate that, if energy constraints are imposed, this resource can be used to accelerate information-processing without relying on entanglement or any other type of quantum correlations. In fact, there are computational problems that can be solved much faster, in comparison to currently used classical schemes, by saving intermediate information in nonorthogonal states of just a single qubit. There are also error correction strategies that protect such computations.

  16. Faster-than-real-time robot simulation for plan development and robot safety

    International Nuclear Information System (INIS)

    Crane, C.D. III; Dalton, R.; Ogles, J.; Tulenko, J.S.; Zhou, X.


    The University of Florida, in cooperation with the Universities of Texas, Tennessee, and Michigan and Oak Ridge National Laboratory (ORNL), is developing an advanced robotic system for the US Department of Energy under the University Program for Robotics for Advanced Reactors. As part of this program, the University of Florida has been pursuing the development of a faster-than-real-time robotic simulation program for planning and control of mobile robotic operations to ensure the efficient and safe operation of mobile robots in nuclear power plants and other hazardous environments

  17. Faster and less phototoxic 3D fluorescence microscopy using a versatile compressed sensing scheme. (United States)

    Woringer, Maxime; Darzacq, Xavier; Zimmer, Christophe; Mir, Mustafa


    Three-dimensional fluorescence microscopy based on Nyquist sampling of focal planes faces harsh trade-offs between acquisition time, light exposure, and signal-to-noise. We propose a 3D compressed sensing approach that uses temporal modulation of the excitation intensity during axial stage sweeping and can be adapted to fluorescence microscopes without hardware modification. We describe implementations on a lattice light sheet microscope and an epifluorescence microscope, and show that images of beads and biological samples can be reconstructed with a 5-10 fold reduction of light exposure and acquisition time. Our scheme opens a new door towards faster and less damaging 3D fluorescence microscopy.

  18. Faster Simulation Methods for the Non-Stationary Random Vibrations of Non-Linear MDOF Systems

    DEFF Research Database (Denmark)

    Askar, A.; Köylüoglu, H. U.; Nielsen, Søren R. K.

    subject to nonstationary Gaussian white noise excitation, as an alternative to conventional direct simulation methods. These alternative simulation procedures rely on an assumption of local Gaussianity during each time step. This assumption is tantamount to various linearizations of the equations....... Such a treatment offers higher rates of convergence, faster speed and higher accuracy. These procedures are compared to the direct Monte Carlo simulation procedure, which uses a fourth order Runge-Kutta scheme with the white noise process approximated by a broad band Ruiz-Penzien broken line process...

  19. Faster Simulation Methods for the Nonstationary Random Vibrations of Non-linear MDOF Systems

    DEFF Research Database (Denmark)

    Askar, A.; Köylüo, U.; Nielsen, Søren R.K.


    subject to nonstationary Gaussian white noise excitation, as an alternative to conventional direct simulation methods. These alternative simulation procedures rely on an assumption of local Gaussianity during each time step. This assumption is tantamount to various linearizations of the equations....... Such a treatment offers higher rates of convergence, faster speed and higher accuracy. These procedures are compared to the direct Monte Carlo simulation procedure, which uses a fourth order Runge-Kutta scheme with the white noise process approximated by a broad band Ruiz-Penzien broken line process...

  20. Heat Capacity Analysis Report

    International Nuclear Information System (INIS)

    Findikakis, A.


    The purpose of this report is to provide heat capacity values for the host and surrounding rock layers for the waste repository at Yucca Mountain. The heat capacity representations provided by this analysis are used in unsaturated zone (UZ) flow, transport, and coupled processes numerical modeling activities, and in thermal analyses as part of the design of the repository to support the license application. Among the reports that use the heat capacity values estimated in this report are the ''Multiscale Thermohydrologic Model'' report, the ''Drift Degradation Analysis'' report, the ''Ventilation Model and Analysis Report, the Igneous Intrusion Impacts on Waste Packages and Waste Forms'' report, the ''Dike/Drift Interactions report, the Drift-Scale Coupled Processes (DST and TH Seepage) Models'' report, and the ''In-Drift Natural Convection and Condensation'' report. The specific objective of this study is to determine the rock-grain and rock-mass heat capacities for the geologic stratigraphy identified in the ''Mineralogic Model (MM3.0) Report'' (BSC 2004 [DIRS 170031], Table 1-1). This report provides estimates of the heat capacity for all stratigraphic layers except the Paleozoic, for which the mineralogic abundance data required to estimate the heat capacity are not available. The temperature range of interest in this analysis is 25 C to 325 C. This interval is broken into three separate temperature sub-intervals: 25 C to 95 C, 95 C to 114 C, and 114 C to 325 C, which correspond to the preboiling, trans-boiling, and postboiling regimes. Heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of material by one degree (Nimick and Connolly 1991 [DIRS 100690], p. 5). The rock-grain heat capacity is defined as the heat capacity of the rock solids (minerals), and does not include the effect of water that exists in the rock pores. By comparison, the rock-mass heat capacity considers the heat capacity of both solids and pore

  1. Recent Changes to the Strength of the CO2 Sink in Boreal Land Regions (Invited) (United States)

    Hayes, D. J.; McGuire, A. D.; Kicklighter, D. W.; Gurney, K. R.; Melillo, J. M.


    Studies suggest that high-latitude terrestrial ecosystems have had a significant influence on the global carbon budget by acting as a substantial sink of atmospheric CO2 over the latter part of the 20th Century. However, recent changes in the controlling factors of this sink, including surface air temperature warming and increases in the frequency and severity of disturbances, have the potential to alter the C balance of boreal land regions. Whether these ecosystems continue to sequester atmospheric CO2 in the face of these changes is a key question in global change science and policy, as any changes to the strength of this major terrestrial sink will have important implications for the global C budget and climate system. Here, we diagnose and attribute contemporary terrestrial CO2 sink strength in the boreal land regions using a biogeochemical process model within a simulation framework that incorporates the impacts of recent changes in atmospheric chemistry and climate variability, as well as fire, forest management and agricultural land use regimes. The simulations estimate that the boreal land regions acted as a net sink of 102 TgC yr-1 from 1960 to 1980 that declined in strength to 28 TgC yr-1 for the 1990s and switched to a source of 99 TgC yr-1 from years 2000 to 2006. The weakening sink strength in the 1990s was largely a result of C losses from Boreal North American tundra and forest ecosystems through increasing decomposition of soil organic matter in response to warmer temperatures. Compared to previous decades, a near doubling of fire emissions was the major factor causing the boreal land regions to switch to a net C source since 2000 when large burn years occurred across the region, particularly in forests of Boreal Asia. A steady sink averaging 23 TgC yr-1 was estimated for Boreal European ecosystems from 1960 to 2006, with the ‘fertilization’ effects of increasing atmospheric CO2 concentration and N deposition primarily responsible for the

  2. Numerical prediction of micro-channel LD heat sink operated with antifreeze based on CFD method (United States)

    Liu, Gang; Liu, Yang; Wang, Chao; Wang, Wentao; Wang, Gang; Tang, Xiaojun


    To theoretically study the feasibility of antifreeze coolants applied as cooling fluids for high power LD heat sink, detailed Computational Fluid Dynamics (CFD) analysis of liquid cooled micro-channels heat sinks is presented. The performance operated with antifreeze coolant (ethylene glycol aqueous solution) compared with pure water are numerical calculated for the heat sinks with the same micro-channels structures. The maximum thermal resistance, total pressure loss (flow resistance), thermal resistance vs. flow-rate, and pressure loss vs. flow-rate etc. characteristics are numerical calculated. The results indicate that the type and temperature of coolants plays an important role on the performance of heat sinks. The whole thermal resistance and pressure loss of heat sinks increase significantly with antifreeze coolants compared with pure water mainly due to its relatively lower thermal conductivity and higher fluid viscosity. The thermal resistance and pressure loss are functions of the flow rate and operation temperature. Increasing of the coolant flow rate can reduce the thermal resistance of heat sinks; meanwhile increase the pressure loss significantly. The thermal resistance tends to a limit with increasing flow rate, while the pressure loss tends to increase exponentially with increasing flow rate. Low operation temperature chiefly increases the pressure loss rather than thermal resistance due to the remarkable increasing of fluid viscosity. The actual working point of the cooling circulation system can be determined on the basis of the pressure drop vs. flow rate curve for the micro-channel heat sink and that for the circulation system. In the same system, if the type or/and temperature of the coolant is changed, the working point is accordingly influenced, that is, working flow rate and pressure is changed simultaneously, due to which the heat sink performance is influenced. According to the numerical simulation results, if ethylene glycol aqueous

  3. Prospects for OPEC capacity

    International Nuclear Information System (INIS)

    Adelman, M.A.


    OPEC capacity is not exogenous, but responds to demand. Price increases have not been caused by capacity shortages. OPEC nations find it hard to set aside even very small portions of their revenues for oil investment, despite its extreme profitability. Foreign investors face high risks. Production sharing makes their after-tax return even more unstable. (author)

  4. A method for intermediate flooding and sinking simulation of a damaged floater in time domain

    Directory of Open Access Journals (Sweden)

    Ju-Sung Kim


    Full Text Available When a floater such as a ship or an offshore structure is damaged in the sea, it is necessary to determine whether the floater will sink in water or not. If the floater will sink, the time to sink should be estimated to make an emergency plan. In addition, causes of the flooding should be investigated carefully. For this purpose, a method for performing intermediate flooding and sinking simulation of the damaged floater in time domain is proposed in this study. Overall process of the proposed method consists of several steps. In the first step, data of the damaged floater such as hull form and compartments are prepared. In the second step, physical characteristics of the floater such as the increased weight considering incoming water, the center of gravity, the changed buoyancy, and the center of buoyancy are calculated at every time step. In the third step, the quasi-static equilibrium position of the floater is calculated. The second and third steps are repeated until the floater reaches to sink or to be in equilibrium. As a result, the final condition of the floater can be determined. To check the feasibility of the proposed method, it is applied to a simple box problem. Finally, it is applied to intermediate flooding simulation of a barge-type damaged floater. Two cases having damaged holes of different locations are selected. As a result, it was confirmed that the floater can be in equilibrium or sink according to the damaged position. The time to be in equilibrium or the time to sink was estimated.

  5. Residual stresses and their mechanisms of production at circumferential weld by heat-sink welding

    International Nuclear Information System (INIS)

    Ueda, Yukio; Nakacho, Keiji; Ohkubo, Katsumi; Shimizu, Tsubasa.


    In the previous report, the authors showed effectiveness of the heat-sink welding (water cooling) to accomplish this end by conducting theoretical analysis and an experiment on residual stresses in the 4B pipe of SUS 304 by the conventional welding and the heat-sink welding at a certain standard heat-input condition. In this research, different pipe sizes and varied heat-input are applied. The welding residual stresses by the conventional welding and the heat-sink welding are obtained by the theoretical analysis and their production mechanisms are clarified. Hence the influence of the above changes of conditions on effectiveness of the heat-sink welding is investigated. The main results are summarized as follow. (1) In case of this pipes such as 2B and 4B pipes, it is important to minimize heat-input per one pass (especially for latter half passes) in order to improve the effectiveness of the heat-sink welding. The effectiveness can be predicted either by theoretical analysis of the temperature distribution history with consideration of the characteristic of heat transfer under spray-watering or by experimental measurement. (2) In case of 24B pipes, thick pipes, it is desirable to minimize heat-input for the first half passes, by which the heat-sink welding becomes more effective. In addition, no matter whether the conventional welding or the heat-sink welding, it is important to prevent angular distorsion which produces tensile axial stresses on the inner surface of the pipe in the weld zone. Possible measures to meet these requirements are to apply restraining jigs, to minimize the section area of the groove (ex. application of the narrow gap arc welding), and to change continuous welding to skip one. (J.P.N.)

  6. Investigating the relative importance of nitrogen deposition on the terrestrial carbon sink in recent decades (United States)

    O'Sullivan, M.; Buermann, W.; Spracklen, D. V.; Gloor, E. U.; Arnold, S.


    The global terrestrial carbon sink has increased since the start of this century at a time of rapidly growing carbon dioxide emissions from fossil fuel burning. Here we test the hypothesis that these parallel increases in fossil fuel burning and terrestrial sink are causally linked via increases in atmospheric CO2 and nitrogen deposition (and carbon-nitrogen interaction). Using the dynamic global vegetation model CLM4.5-BGC, we performed factorial analyses, separating the effects of individual drivers to changes in carbon fluxes and sinks. Globally, we found that increases in nitrogen deposition from 1900 to 2016 led to an additional 32 PgC stored. 40% of this increase could be attributed to East Asia and Europe alone, with North America also having a significant contribution. The global, post-2000 anthropogenic nitrogen deposition effect on terrestrial carbon uptake was 0.7 PgC/yr (20% of the total sink). Comparing the past decade (2005-2016) to the previous (1990-2005), regionally, we find nitrogen deposition to be an important driver of changes in net carbon uptake. In East Asia, increases in nitrogen deposition contributed 26% of the total increase in carbon uptake, with direct CO2 fertilization contributing 67%, and the synergistic carbon-nitrogen effect explaining 7% of the sink. Conversely, declining nitrogen deposition rates over North America contributed negatively (-35%) to the carbon sink, with a near zero contribution from the synergistic effect. At global scale, however, our findings suggest that changes in nitrogen deposition (both direct and via increasing the efficiency of the CO2 fertilization effect) played only a minor role in the enhanced plant carbon uptake and sink activity during the most recent decade. This finding is due to regional compensations but also suggesting that other factors (direct CO2, climate, land use change) may have been more important drivers.

  7. Carbon source-sink relationship in Arabidopsis thaliana: the role of sucrose transporters. (United States)

    Durand, Mickaël; Mainson, Dany; Porcheron, Benoît; Maurousset, Laurence; Lemoine, Rémi; Pourtau, Nathalie


    The regulation of source-to-sink sucrose transport is associated with AtSUC and AtSWEET sucrose transporters' gene expression changes in plants grown hydroponically under different physiological conditions. Source-to-sink transport of sucrose is one of the major determinants of plant growth. Whole-plant carbohydrates' partitioning requires the specific activity of membrane sugar transporters. In Arabidopsis thaliana plants, two families of transporters are involved in sucrose transport: AtSUCs and AtSWEETs. This study is focused on the comparison of sucrose transporter gene expression, soluble sugar and starch levels and long distance sucrose transport, in leaves and sink organs (mainly roots) in different physiological conditions (along the plant life cycle, during a diel cycle, and during an osmotic stress) in plants grown hydroponically. In leaves, the AtSUC2, AtSWEET11, and 12 genes known to be involved in phloem loading were highly expressed when sucrose export was high and reduced during osmotic stress. In roots, AtSUC1 was highly expressed and its expression profile in the different conditions tested suggests that it may play a role in sucrose unloading in roots and in root growth. The SWEET transporter genes AtSWEET12, 13, and 15 were found expressed in all organs at all stages studied, while differential expression was noticed for AtSWEET14 in roots, stems, and siliques and AtSWEET9, 10 expressions were only detected in stems and siliques. A role for these transporters in carbohydrate partitioning in different source-sink status is proposed, with a specific attention on carbon demand in roots. During development, despite trophic competition with others sinks, roots remained a significant sink, but during osmotic stress, the amount of translocated [U- 14 C]-sucrose decreased for rosettes and roots. Altogether, these results suggest that source-sink relationship may be linked with the regulation of sucrose transporter gene expression.

  8. Sensitivity analyses of OH missing sinks over Tokyo metropolitan area in the summer of 2007

    Directory of Open Access Journals (Sweden)

    K. Ishii


    Full Text Available OH reactivity is one of key indicators which reflect impacts of photochemical reactions in the atmosphere. An observation campaign has been conducted in the summer of 2007 at the heart of Tokyo metropolitan area to measure OH reactivity. The total OH reactivity measured directly by the laser-induced pump and probe technique was higher than the sum of the OH reactivity calculated from concentrations and reaction rate coefficients of individual species measured in this campaign. And then, three-dimensional air quality simulation has been conducted to evaluate the simulation performance on the total OH reactivity including "missing sinks", which correspond to the difference between the measured and calculated total OH reactivity. The simulated OH reactivity is significantly underestimated because the OH reactivity of volatile organic compounds (VOCs and missing sinks are underestimated. When scaling factors are applied to input emissions and boundary concentrations, a good agreement is observed between the simulated and measured concentrations of VOCs. However, the simulated OH reactivity of missing sinks is still underestimated. Therefore, impacts of unidentified missing sinks are investigated through sensitivity analyses. In the cases that unknown secondary products are assumed to account for unidentified missing sinks, they tend to suppress formation of secondary aerosol components and enhance formation of ozone. In the cases that unidentified primary emitted species are assumed to account for unidentified missing sinks, a variety of impacts may be observed, which could serve as precursors of secondary organic aerosols (SOA and significantly increase SOA formation. Missing sinks are considered to play an important role in the atmosphere over Tokyo metropolitan area.

  9. Domain Organization in Clostridium botulinum Neurotoxin Type E is Unique: Its Implication in Faster Translocation

    Energy Technology Data Exchange (ETDEWEB)

    Kumaran, D.; Eswaramoorthy, S; Furey, W; Navaza, J; Sax, M; Swaminathan, S


    Clostridium botulinum produces seven antigenically distinct neurotoxins [C. botulinum neurotoxins (BoNTs) A-G] sharing a significant sequence homology. Based on sequence and functional similarity, it was believed that their three-dimensional structures will also be similar. Indeed, the crystal structures of BoNTs A and B exhibit similar fold and domain association where the translocation domain is flanked on either side by binding and catalytic domains. Here, we report the crystal structure of BoNT E holotoxin and show that the domain association is different and unique, although the individual domains are similar to those of BoNTs A and B. In BoNT E, both the binding domain and the catalytic domain are on the same side of the translocation domain, and all three have mutual interfaces. This unique association may have an effect on the rate of translocation, with the molecule strategically positioned in the vesicle for quick entry into cytosol. Botulism, the disease caused by BoNT E, sets in faster than any other serotype because of its speedy internalization and translocation, and the present structure offers a credible explanation. We propose that the translocation domain in other BoNTs follows a two-step process to attain translocation-competent conformation as in BoNT E. We also suggest that this translocation-competent conformation in BoNT E is a probable reason for its faster toxic rate compared to BoNT A. However, this needs further experimental elucidation.

  10. Inspiratory muscles experience fatigue faster than the calf muscles during treadmill marching. (United States)

    Perlovitch, Renana; Gefen, Amit; Elad, David; Ratnovsky, Anat; Kramer, Mordechai R; Halpern, Pinchas


    The possibility that respiratory muscles may fatigue during extreme physical activity and thereby become a limiting factor leading to exhaustion is debated in the literature. The aim of this study was to determine whether treadmill marching exercise induces respiratory muscle fatigue, and to compare the extent and rate of respiratory muscle fatigue to those of the calf musculature. To identify muscle fatigue, surface electromyographic (EMG) signals of the inspiratory (sternomastoid, external intercostals), expiratory (rectus abdominis and external oblique) and calf (gastrocnemius lateralis) muscles were measured during a treadmill march of 2 km at a constant velocity of 8 km/h. The extent of fatigue was assessed by determining the increase in root-mean-square (RMS) of EMG over time, and the rate of fatigue was assessed from the slope of the EMG RMS versus time curve. Results indicated that (i) the inspiratory and calf muscles are the ones experiencing the most dominant fatigue during treadmill marching, (ii) the rate of fatigue of each muscle group was monotonic between the initial and terminal phases of exercise, and (iii) the inspiratory muscles fatigue significantly faster than the calf at the terminal phase of exercise, and are likely to fatigue faster during the initial exercise as well. Accordingly, this study supports the hypothesis that fatigue of the inspiratory muscles may be a limiting factor during exercise.

  11. Does catatonic schizophrenia improve faster with electroconvulsive therapy than other subtypes of schizophrenia? (United States)

    Thirthalli, Jagadisha; Phutane, Vivek H; Muralidharan, Kesavan; Kumar, Channaveerachari Naveen; Munishwar, Bharat; Baspure, Prashant; Gangadhar, Bangalore N


    Electroconvulsive therapy (ECT) is generally recommended for treating catatonic schizophrenia. Non-catatonic schizophrenia patients also receive ECT. We compared the speed of response to ECT among patients with catatonic and other subtypes of schizophrenia. Consecutive schizophrenia patients referred for ECT within 3 months of starting antipsychotic treatment were studied (19 with catatonic and 34 with non-catatonic schizophrenia). Nurse's Observation Scale for Inpatient Evaluation (NOSIE-30) and Clinical Global Impression (CGI) were used to rate improvement. Referring psychiatrists stopped ECTs based on clinical impression of improvement. Total number of ECTs was taken as an indirect measure of speed of response. NOSIE-30 scores were compared using repeated measures analysis of variance. Catatonic schizophrenia patients required significantly fewer ECTs to achieve clinically significant improvement. There was a significant group x occasion effect in NOSIE scores, suggesting faster response to ECT in the catatonia group (F=41.6; Pcatatonic schizophrenia required significantly fewer ECTs (one less session on an average) to achieve clinical improvement (Log-rank statistic =5.31; P=0.02). Catatonic schizophrenia responds faster to ECT than non-catatonic schizophrenia. However, the magnitude of the difference is modest.

  12. The impact of accelerating faster than exponential population growth on genetic variation. (United States)

    Reppell, Mark; Boehnke, Michael; Zöllner, Sebastian


    Current human sequencing projects observe an abundance of extremely rare genetic variation, suggesting recent acceleration of population growth. To better understand the impact of such accelerating growth on the quantity and nature of genetic variation, we present a new class of models capable of incorporating faster than exponential growth in a coalescent framework. Our work shows that such accelerated growth affects only the population size in the recent past and thus large samples are required to detect the models' effects on patterns of variation. When we compare models with fixed initial growth rate, models with accelerating growth achieve very large current population sizes and large samples from these populations contain more variation than samples from populations with constant growth. This increase is driven almost entirely by an increase in singleton variation. Moreover, linkage disequilibrium decays faster in populations with accelerating growth. When we instead condition on current population size, models with accelerating growth result in less overall variation and slower linkage disequilibrium decay compared to models with exponential growth. We also find that pairwise linkage disequilibrium of very rare variants contains information about growth rates in the recent past. Finally, we demonstrate that models of accelerating growth may substantially change estimates of present-day effective population sizes and growth times.

  13. Faster recovery of a diatom from UV damage under ocean acidification. (United States)

    Wu, Yaping; Campbell, Douglas A; Gao, Kunshan


    Diatoms are the most important group of primary producers in marine ecosystems. As oceanic pH declines and increased stratification leads to the upper mixing layer becoming shallower, diatoms are interactively affected by both lower pH and higher average exposures to solar ultraviolet radiation. The photochemical yields of a model diatom, Phaeodactylum tricornutum, were inhibited by ultraviolet radiation under both growth and excess light levels, while the functional absorbance cross sections of the remaining photosystem II increased. Cells grown under ocean acidification (OA) were less affected during UV exposure. The recovery of PSII under low photosynthetically active radiation was much faster than in the dark, indicating that photosynthetic processes were essential for the full recovery of photosystem II. This light dependent recovery required de novo synthesized protein. Cells grown under ocean acidification recovered faster, possibly attributable to higher CO₂ availability for the Calvin cycle producing more resources for repair. The lower UV inhibition combined with higher recovery rate under ocean acidification could benefit species such as P.tricornutum, and change their competitiveness in the future ocean. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Ear Detection under Uncontrolled Conditions with Multiple Scale Faster Region-Based Convolutional Neural Networks

    Directory of Open Access Journals (Sweden)

    Yi Zhang


    Full Text Available Ear detection is an important step in ear recognition approaches. Most existing ear detection techniques are based on manually designing features or shallow learning algorithms. However, researchers found that the pose variation, occlusion, and imaging conditions provide a great challenge to the traditional ear detection methods under uncontrolled conditions. This paper proposes an efficient technique involving Multiple Scale Faster Region-based Convolutional Neural Networks (Faster R-CNN to detect ears from 2D profile images in natural images automatically. Firstly, three regions of different scales are detected to infer the information about the ear location context within the image. Then an ear region filtering approach is proposed to extract the correct ear region and eliminate the false positives automatically. In an experiment with a test set of 200 web images (with variable photographic conditions, 98% of ears were accurately detected. Experiments were likewise conducted on the Collection J2 of University of Notre Dame Biometrics Database (UND-J2 and University of Beira Interior Ear dataset (UBEAR, which contain large occlusion, scale, and pose variations. Detection rates of 100% and 98.22%, respectively, demonstrate the effectiveness of the proposed approach.

  15. The Development of Future Orientation is Associated with Faster Decline in Hopelessness during Adolescence. (United States)

    Mac Giollabhui, Naoise; Nielsen, Johanna; Seidman, Sam; Olino, Thomas M; Abramson, Lyn Y; Alloy, Lauren B


    Hopelessness is implicated in multiple psychological disorders. Little is known, however, about the trajectory of hopelessness during adolescence or how emergent future orientation may influence its trajectory. Parallel process latent growth curve modelling tested whether (i) trajectories of future orientation and hopelessness and (ii) within-individual change in future orientation and hopelessness were related. The study was comprised of 472 adolescents [52% female, 47% Caucasian, 47% received free lunch] recruited at ages 12-13 who completed measures of future orientation and hopelessness at five annual assessments. The results indicate that a general decline in hopelessness across adolescence occurs quicker for those experiencing faster development of future orientation, when controlling for age, sex, low socio-economic status in addition to stressful life events in childhood and adolescence. Stressful childhood life events were associated with worse future orientation at baseline and negative life events experienced during adolescence were associated with both an increase in the trajectory of hopelessness as well as a decrease in the trajectory of future orientation. This study provides compelling evidence that the development of future orientation during adolescence is associated with a faster decline in hopelessness.

  16. Is starting with the feet out of the water faster in backstroke swimming? (United States)

    Nguyen, Cecilia; Bradshaw, Elizabeth J; Pease, David; Wilson, Cameron


    This study aimed to determine if starting with the feet above the water (FAW) in male backstroke swimming resulted in faster start times (15-m time) than when the feet were underwater (FUW). It was hypothesised that setting higher on the wall would generate increased horizontal force and velocity, resulting in quicker starts. Twelve high-level male backstrokers performed three trials of the FAW and FUW techniques. A biomechanical swimming testing system comprising one force plate (1,000 Hz), four lateral-view (100Hz), and five overhead (50Hz) video cameras captured the swimmers' performance. Data for each participant's fastest trial for each technique were collated, grouped, and statistically analysed. Analysis included Wilcoxon, Spearman Rho correlation, and regression analysis. Wilcoxon results revealed a significantly faster start time for the FAW technique (p < 0.01). Peak horizontal force was significantly smaller for FAW (p = 0.02), while take-off horizontal velocity was significantly greater (p = 0.01). Regression analysis indicated take-off horizontal velocity to be a good predictor of start time for both techniques, and the horizontal displacement of the centre of mass for the FAW start.

  17. Faster Development Covaries with Higher DNA Damage in Grasshoppers (Chorthippus albomarginatus) from Chernobyl. (United States)

    Bonisoli-Alquati, Andrea; Ostermiller, Shanna; Beasley, De Anna E; Welch, Shane M; Møller, Anders P; Mousseau, Timothy A

    In Chernobyl, chronic exposure to radioactive contaminants has a variety of deleterious effects on exposed organisms, including genetic damage and mutation accumulation. However, the potential for such effects to be transmitted to the next generation is poorly understood. We captured lesser marsh grasshoppers (Chorthippus albomarginatus) in the Chernobyl Exclusion Zone from sites varying in levels of environmental radiation by more than three orders of magnitude. We then raised their offspring in a common garden experiment in order to assess the effects of parental exposure to radiation on offspring development and DNA damage. Offspring that reached maturity at a younger age had higher levels of DNA damage. Contrary to our hypothesis, parental exposure to radioactive contamination did not affect DNA damage in their offspring possibly because of intervening adaptation or parental compensatory mechanisms. Our results suggest a trade-off between developmental rate and resistance to DNA damage, whereby offspring developing at faster rates do so at the cost of damaging their DNA. This result is consistent with and extends findings in other species, suggesting that faster growth rates cause increased oxidative damage and stress. We propose that growth rates are subject to stabilizing selection balancing the benefits of fast development and the competing need of buffering its damaging effects to macromolecules and tissues.

  18. Faster in-plane switching and reduced rotational viscosity characteristics in a graphene-nematic suspension

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Rajratan, E-mail:; Kinnamon, Daniel; Skaggs, Nicole; Womack, James [Soft Matter and Nanomaterials Laboratory, Department of Physics, The United States Naval Academy, Annapolis, Maryland 21402 (United States)


    The in-plane switching (IPS) for a nematic liquid crystal (LC) was found to be considerably faster when the LC was doped with dilute concentrations of monolayer graphene flakes. Additional studies revealed that the presence of graphene reduced the rotational viscosity of the LC, permitting the nematic director to respond quicker in IPS mode on turning the electric field on. The studies were carried out with several graphene concentrations in the LC, and the experimental results coherently suggest that there exists an optimal concentration of graphene, allowing a reduction in the IPS response time and rotational viscosity in the LC. Above this optimal graphene concentration, the rotational viscosity was found to increase, and consequently, the LC no longer switched faster in IPS mode. The presence of graphene suspension was also found to decrease the LC's pretilt angle significantly due to the π-π electron stacking between the LC molecules and graphene flakes. To understand the π-π stacking interaction, the anchoring mechanism of the LC on a CVD grown monolayer graphene film on copper substrate was studied by reflected crossed polarized microscopy. Optical microphotographs revealed that the LC alignment direction depended on monolayer graphene's hexagonal crystal structure and its orientation.

  19. They all like it hot: faster cleanup of contaminated soil and groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Newmark, R., LLNL


    Clean up a greasy kitchen spill with cold water and the going is slow. Us hot water instead and progress improves markedly. So it makes sense that cleanup of greasy underground contaminants such as gasoline might go faster if hot water or steam were somehow added to the process. The Environmental Protection Agency named hundreds of sites to the Superfund list - sites that have been contaminated with petroleum products or petroleum products or solvents. Elsewhere across the country, thousands of properties not identified on federal cleanup lists are contaminated as well. Given that under current regulations, underground accumulations of solvent and hydrocarbon contaminants (the most serious cause of groundwater pollution) must be cleaned up, finding a rapid and effective method of removing them is imperative. In the early 1990`s, in collaboration with the School of Engineering at the University of California at Berkeley, Lawrence Livermore developed dynamic underground stripping. This method for treating underground contaminants with heat is much faster and more effective than traditional treatment methods.

  20. Transitions in the Communication Capacity of Dissipative Qubit Channels (United States)

    Daems, D.


    The information transmission is studied for quantum channels in which the noise includes dissipative effects, more specifically, nonunitality. Noise is usually a nuisance but can sometimes be helpful. For these channels, the communication capacity is shown to increase with the dissipative component of the noise and may exhibit transitions beyond which it increases faster. The optimal states are constructed analytically as well as the pertaining “phase” diagram.

  1. Event-related potential indices of inter-individual and age differences in visual attention capacity

    DEFF Research Database (Denmark)

    Wiegand, Iris; Töllner, Thomas; Dyrholm, Mads

    in these two functions: The posterior N1 was smaller for participants with faster relative to slower processing speed and the Contralateral Delay Activity (CDA) was larger for participants with higher relative to lower storage capacity. When we extended the approach to investigate neural underpinnings of age......-related changes in attentional capacities, these ERP markers of individual differences in processing speed and storage capacity were validated in an older group. Furthermore, additional components were related to performance exclusively in older inidividuals: Anterior N1 amplitudes were reduced for slower older...... participants (relative to younger and faster older participants) and high-storage capacity older participants (relative to younger and low-storage capacity older participants) obtained a stronger right-central positivity, which correlated with K-values only in the older group. Our findings indicate...

  2. Treatment of the loss of ultimate heat sink initiating events in the IRSN level 1 PSA

    International Nuclear Information System (INIS)

    Dupuy, Patricia; Georgescu, Gabriel; Corenwinder, Francois


    The total loss of the ultimate heat sink is an initiating event which, even it is mainly of external origin, has been considered in the frame of internal events Level 1 PSA by IRSN. The on-going actions on the development of external hazards PSA and the recent incident of loss of the heat sink induced by the ingress of vegetable matter that occurred in France in 2009 have pointed out the need to improve the modeling of the loss of the heat sink initiating event and sequences to better take into account the fact that this loss may be induced by external hazards and thus affect all the site units. The paper presents the historical steps of the modeling of the total loss of the heat sink, the safety stakes of this modeling, the main assumptions used by IRSN in the associated PSA for the 900 MWe reactors and the results obtained. The total loss of the heat sink was not initially addressed in the safety demonstration of French NPPs. On the basis of the insights of the first probabilistic assessments performed in the 80's, the risks associated to this 'multiple failure situation' turned out to be very significant and design and organisational improvements were implemented on the plants. Reviews of the characterization of external hazards and of their consequences on the installations and French operating feedback have revealed that extreme hazards may induce a total loss of the heat sink. Moreover, the accident that occurred at Fukushima in 2011 has pointed out the risk of such a loss of long duration at all site units in case of extreme hazards. In this context, it seems relevant to further improve the modelling of the total loss of the heat sink by considering the external hazards that may cause this loss. In a first step, IRSN has improved the assumptions and data used in the loss of the heat sink PSA model, in particular by considering that such a loss may affect all the site units. The next challenge will be the deeper analysis of the impact of external hazards on

  3. Backup and Ultimate Heat Sinks in CANDU Reactors For Prolonged SBO Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Nitheanandan, T.; Brown, M. J. [Atomic Energy of Canada Limited, Ontario (Canada)


    In a pressurized heavy water reactor, following loss of the primary coolant, severe core damage would begin with the depletion of the liquid moderator, exposing the top row of internally-voided fuel channels to steam cooling conditions on the inside and outside. The uncovered fuel channels would heat up, deform and disassemble into core debris. Large inventories of water passively reduce the rate of progression of the accident, prolonging the time for complete loss of engineered heat sinks. The efficacy of available backup and ultimate heat sinks, available in a CANDU 6 reactor, in mitigating the consequences of a prolonged station blackout scenario was analysed using the MAAP4-CANDU code. The analysis indicated that the steam generator secondary side water inventory is the most effective heat sink during the accident. Additional heat sinks such as the primary coolant, moderator, calandria vault water and end shield water are also able to remove decay heat; however, a gradually increasing mismatch between heat generation and heat removal occurs over the course of the postulated event. This mismatch is equivalent to an additional water inventory estimated to be 350,000 kg at the time of calandria vessel failure. In the Enhanced CANDU 6 reactor ∼2,040,000 kg of water in the reserve water tank is available for prolonged emergencies requiring heat sinks.

  4. Global land carbon sink response to temperature and precipitation varies with ENSO phase

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yuanyuan; Michalak, Anna M.; Schwalm, Christopher R.; Huntzinger, Deborah N.; Berry, Joseph A.; Ciais, Philippe; Piao, Shilong; Poulter, Benjamin; Fisher, Joshua B.; Cook, Robert B.; Hayes, Daniel; Huang, Maoyi; Ito, Akihiko; Jain, Atul; Lei, Huimin; Lu, Chaoqun; Mao, Jiafu; Parazoo, Nicholas C.; Peng, Shushi; Ricciuto, Daniel M.; Shi, Xiaoying; Tao, Bo; Tian, Hanqin; Wang, Weile; Wei, Yaxing; Yang, Jia


    Climate variability associated with the El Niño-Southern Oscillation (ENSO) and its consequent impacts on land carbon sink interannual variability have been used as a basis for investigating carbon cycle responses to climate variability more broadly, and to inform the sensitivity of the tropical carbon budget to climate change. Past studies have presented opposing views about whether temperature or precipitation is the primary factor driving the response of the land carbon sink to ENSO. Here, we show that the dominant driver varies with ENSO phase. Whereas tropical temperature explains sink dynamics following El Niño conditions (rTG,P=0.59, p<0.01), the post La Niña sink is driven largely by tropical precipitation (rPG,T=-0.46, p=0.04). This finding points to an ENSO-phase-dependent interplay between water availability and temperature in controlling the carbon uptake response to climate variations in tropical ecosystems. We further find that none of a suite of ten contemporary terrestrial biosphere models captures these ENSO-phase-dependent responses, highlighting a key uncertainty in modeling climate impacts on the future of the global land carbon sink.

  5. Is there a decrease in the sink of atmospheric CO2 in the Nordic seas?

    International Nuclear Information System (INIS)

    Olsen, Are; Anderson, Leif G.


    It is well known that the seas off Norway sink a lot of carbon dioxide from the atmosphere, mainly because of the large heat loss from the sea in the area, which makes CO 2 more soluble in the water. Whether this sink has increased after the industrial revolution and thereby contributes to slowing down the increase of atmospheric CO 2 is uncertain. That is, it is uncertain whether there is a sink of anthropogenic CO 2 . There are indications that the opposite is true, that the sink of CO 2 in this area has slowed down along with the rise in the concentration of atmospheric CO 2 . Storing of anthropogenic CO 2 , however, takes place at higher latitudes where deep-water formation occurs, such as in the Nordic seas, where water that is saturated with anthropogenic CO 2 is transported down in the deep sea and becomes shielded from the atmosphere. Model calculations show that increased CO 2 in the atmosphere will reduce the sink of this gas in the Nordic seas. This conclusion is supported by observations from the Barents Sea

  6. Dissolution studies of poorly soluble drug nanosuspensions in non-sink conditions. (United States)

    Liu, Peng; De Wulf, Odile; Laru, Johanna; Heikkilä, Teemu; van Veen, Bert; Kiesvaara, Juha; Hirvonen, Jouni; Peltonen, Leena; Laaksonen, Timo


    Sink conditions used in dissolution tests lead to rapid dissolution rates for nanosuspensions, causing difficulties in discriminating dissolution profiles between different formulations. Here, non-sink conditions were studied for the dissolution testing of poorly water-soluble drug nanosuspensions. A mathematical model for polydispersed particles was established to clarify dissolution mechanisms. The dissolution of nanosuspensions with either a monomodal or bimodal size distribution was simulated. In the experimental part, three different particle sizes of indomethacin nanosuspensions were prepared by the wet milling technique. The effects of the dissolution medium pH and agitation speed on dissolution rate were investigated. The dissolution profiles in sink and non-sink conditions were obtained by changing the ratio of sample amount to the saturation solubility. The results of the simulations and experiments indicated that when the sample amount was increased to the saturation solubility of drug, the slowest dissolution rate and the best discriminating dissolution profiles were obtained. Using sink conditions or too high amount of the sample will increase the dissolution rate and weaken the discrimination between dissolution profiles. Furthermore, the low solubility by choosing a proper pH of the dissolution medium was helpful in getting discriminating dissolution profiles, whereas the agitation speed appeared to have little influence on the dissolution profiles. This discriminatory method is simple to perform and can be potentially used in any nanoproduct development and quality control studies.

  7. Discrete Particle Swarm Optimization Routing Protocol for Wireless Sensor Networks with Multiple Mobile Sinks (United States)

    Yang, Jin; Liu, Fagui; Cao, Jianneng; Wang, Liangming


    Mobile sinks can achieve load-balancing and energy-consumption balancing across the wireless sensor networks (WSNs). However, the frequent change of the paths between source nodes and the sinks caused by sink mobility introduces significant overhead in terms of energy and packet delays. To enhance network performance of WSNs with mobile sinks (MWSNs), we present an efficient routing strategy, which is formulated as an optimization problem and employs the particle swarm optimization algorithm (PSO) to build the optimal routing paths. However, the conventional PSO is insufficient to solve discrete routing optimization problems. Therefore, a novel greedy discrete particle swarm optimization with memory (GMDPSO) is put forward to address this problem. In the GMDPSO, particle’s position and velocity of traditional PSO are redefined under discrete MWSNs scenario. Particle updating rule is also reconsidered based on the subnetwork topology of MWSNs. Besides, by improving the greedy forwarding routing, a greedy search strategy is designed to drive particles to find a better position quickly. Furthermore, searching history is memorized to accelerate convergence. Simulation results demonstrate that our new protocol significantly improves the robustness and adapts to rapid topological changes with multiple mobile sinks, while efficiently reducing the communication overhead and the energy consumption. PMID:27428971

  8. Thermal management of electronics using phase change material based pin fin heat sinks

    International Nuclear Information System (INIS)

    Baby, R; Balaji, C


    This paper reports the results of an experimental study carried out to explore the thermal characteristics of phase change material based heat sinks for electronic equipment cooling. The phase change material (PCM) used in this study is n – eicosane. All heat sinks used in the present study are made of aluminium with dimensions of 80 × 62 mm 2 base with a height of 25 mm. Pin fins acts as the thermal conductivity enhancer (TCE) to improve the distribution of heat more uniformly as the thermal conductivity of the PCM is very low. A total of three different pin fin heat sink geometries with 33, 72 and 120 pin fins filled with phase change materials giving rise to 4%, 9% and 15% volume fractions of the TCE respectively were experimentally investigated. Baseline comparisons are done with a heat sink filled with PCM, without any fin. Studies are conducted for heat sinks on which a uniform heat load is applied at the bottom for the finned and unfinned cases. The effect of pin fins of different volume fractions with power levels ranging from 4 to 8 W corresponding to a heat flux range of 1. 59 to 3.17 kW/m 2 , was explored in this paper. The volume fraction of the PCM (PCM volume / (Total volume – fin volume)) is also varied as 0. 3, 0.6 and 1 to determine the effect of PCM volume on the overall performance of the electronic equipment.

  9. Dynamic sink assignment for efficient energy consumption in wireless sensor networks

    KAUST Repository

    Oikonomou, Konstantinos N.


    Efficient energy consumption is a challenging problem in wireless sensor networks (WSNs) and closely related to extending network lifetime. The usual way of tackling this issue for topologies with fixed link weight and fixed sink location, has been shown to be severely affected by the energy hole problem. In this paper, the energy consumption problem is initially studied for WSNs with fixed sink assignment and it is analytically shown that energy consumption is minimized when the sink is assigned to the node that is the solution of a suitably formulated 1-median problem. This motivates the introduction of a dynamic environment where link weights change based on the energy level and the aggregate traffic load of the adjacent nodes. Then, the sink is adaptively allowed to move among neighbor nodes, according to a scalable sink migration strategy. Simulation results support the analytical claims demonstrating energy consumption reduction and an additional network lifetime increment when migration is employed in the dynamic environment. © 2012 IEEE.

  10. Discrete Particle Swarm Optimization Routing Protocol for Wireless Sensor Networks with Multiple Mobile Sinks. (United States)

    Yang, Jin; Liu, Fagui; Cao, Jianneng; Wang, Liangming


    Mobile sinks can achieve load-balancing and energy-consumption balancing across the wireless sensor networks (WSNs). However, the frequent change of the paths between source nodes and the sinks caused by sink mobility introduces significant overhead in terms of energy and packet delays. To enhance network performance of WSNs with mobile sinks (MWSNs), we present an efficient routing strategy, which is formulated as an optimization problem and employs the particle swarm optimization algorithm (PSO) to build the optimal routing paths. However, the conventional PSO is insufficient to solve discrete routing optimization problems. Therefore, a novel greedy discrete particle swarm optimization with memory (GMDPSO) is put forward to address this problem. In the GMDPSO, particle's position and velocity of traditional PSO are redefined under discrete MWSNs scenario. Particle updating rule is also reconsidered based on the subnetwork topology of MWSNs. Besides, by improving the greedy forwarding routing, a greedy search strategy is designed to drive particles to find a better position quickly. Furthermore, searching history is memorized to accelerate convergence. Simulation results demonstrate that our new protocol significantly improves the robustness and adapts to rapid topological changes with multiple mobile sinks, while efficiently reducing the communication overhead and the energy consumption.

  11. Vedr.: Military capacity building

    DEFF Research Database (Denmark)

    Larsen, Josefine Kühnel; Struwe, Lars Bangert


    Military capacity building has increasingly become an integral part of Danish defence. Military capacity is a new way of thinking Danish defence and poses a new set of challenges and opportunities for the Danish military and the Political leadership. On the 12th of december, PhD. Candidate Josefine...... Kühnel Larsen and researcher Lars Bangert Struwe of CMS had organized a seminar in collaboration with Royal Danish Defense Colleg and the East African Security Governance Network. The seminar focused on some of the risks involved in Military capacity building and how these risks are dealt with from...

  12. The Mpemba effect: When can hot water freeze faster than cold? (United States)

    Jeng, Monwhea


    We review the Mpemba effect, where initially hot water freezes faster than initially cold water. Although the effect might appear impossible, it has been observed in numerous experiments and was discussed by Aristotle, Francis Bacon, Roger Bacon, and Descartes. It has a rich and fascinating history, including the story of the secondary school student, Erasto Mpemba, who reintroduced the effect to the twentieth century scientific community. The phenomenon is simple to describe and illustrates numerous important issues about the scientific method: the role of skepticism in scientific inquiry, the influence of theory on experiment and observation, the need for precision in the statement of a scientific hypothesis, and the nature of falsifiability. Proposed theoretical mechanisms for the Mpemba effect and the results of contemporary experiments on the phenomenon are surveyed. The observation that hot water pipes are more likely to burst than cold water pipes is also discussed.

  13. Decadally cycling soil carbon is more sensitive to warming than faster-cycling soil carbon. (United States)

    Lin, Junjie; Zhu, Biao; Cheng, Weixin


    The response of soil organic carbon (SOC) pools to globally rising surface temperature crucially determines the feedback between climate change and the global carbon cycle. However, there is a lack of studies investigating the temperature sensitivity of decomposition for decadally cycling SOC which is the main component of total soil carbon stock and the most relevant to global change. We tackled this issue using two decadally (13) C-labeled soils and a much improved measuring system in a long-term incubation experiment. Results indicated that the temperature sensitivity of decomposition for decadally cycling SOC (>23 years in one soil and >55 years in the other soil) was significantly greater than that for faster-cycling SOC (will likely make this large SOC stock vulnerable to loss by global warming in the 21st century and beyond. © 2015 John Wiley & Sons Ltd.

  14. Faster is more different: mean-field dynamics of innovation diffusion. (United States)

    Baek, Seung Ki; Durang, Xavier; Kim, Mina


    Based on a recent model of paradigm shifts by Bornholdt et al., we studied mean-field opinion dynamics in an infinite population where an infinite number of ideas compete simultaneously with their values publicly known. We found that a highly innovative society is not characterized by heavy concentration in highly valued ideas: Rather, ideas are more broadly distributed in a more innovative society with faster progress, provided that the rate of adoption is constant, which suggests a positive correlation between innovation and technological disparity. Furthermore, the distribution is generally skewed in such a way that the fraction of innovators is substantially smaller than has been believed in conventional innovation-diffusion theory based on normality. Thus, the typical adoption pattern is predicted to be asymmetric with slow saturation in the ideal situation, which is compared with empirical data sets.

  15. Faster is more different: mean-field dynamics of innovation diffusion.

    Directory of Open Access Journals (Sweden)

    Seung Ki Baek

    Full Text Available Based on a recent model of paradigm shifts by Bornholdt et al., we studied mean-field opinion dynamics in an infinite population where an infinite number of ideas compete simultaneously with their values publicly known. We found that a highly innovative society is not characterized by heavy concentration in highly valued ideas: Rather, ideas are more broadly distributed in a more innovative society with faster progress, provided that the rate of adoption is constant, which suggests a positive correlation between innovation and technological disparity. Furthermore, the distribution is generally skewed in such a way that the fraction of innovators is substantially smaller than has been believed in conventional innovation-diffusion theory based on normality. Thus, the typical adoption pattern is predicted to be asymmetric with slow saturation in the ideal situation, which is compared with empirical data sets.

  16. Are protein hubs faster folders? Exploration based on Escherichia coli proteome. (United States)

    Xu, Hong-Rui; Cheng, Jun-Feng; Hu, Xiao-Pan; Chu, Ying-Ying; Ma, Bin-Guang


    Protein hubs in protein-protein interaction network are especially important due to their central roles in the entire network. Despite of their importance, the folding kinetics of hub proteins in comparison with non-hubs is still unknown. In this work, the folding rates for protein hubs and non-hubs were predicted and compared for the interactome of Escherichia coli K12, and the results showed that hub proteins fold faster than non-hub proteins. A possible explanation might be that protein hubs have more and fast-folding structural conformations than non-hubs, which leads to the notion of "hub of hubs" in the protein conformation space. It was found that the sequence and structure features relevant to protein folding rates are also different between hub and non-hub proteins. Moreover, the interacting proteins tend to have similar folding rates. These results gave insightful implications for understanding the interplay between the mechanisms of protein folding and interaction.

  17. Pain hypersensitivity in congenital blindness is associated with faster central processing of C-fibre input

    DEFF Research Database (Denmark)

    Slimani, H.; Plaghki, L.; Ptito, M.


    Background We have recently shown that visual deprivation from birth exacerbates responses to painful thermal stimuli. However, the mechanisms underlying pain hypersensitivity in congenital blindness are unclear. Methods To study the contribution of Aδ- and C-fibres in pain perception, we measured...... instructed to respond as quickly as possible when detecting a laser-induced sensation. We used a 650 ms cut-off criterion to distinguish fast Aδ- from slow C-fibre–mediated sensations. Results Congenitally blind participants showed significantly faster reaction times to C- but not to Aδ......-fibre–mediated sensations. In contrast, thresholds for Aδ- and C-fibre stimulation did not differ between groups. Late blind individuals did not differ from sighted controls in any aspect. A follow-up experiment using only suprathreshold stimuli for Aδ- and C-fibre activation confirmed these findings and further showed...

  18. Faster growth of the major prokaryotic versus eukaryotic CO2 fixers in the oligotrophic ocean. (United States)

    Zubkov, Mikhail V


    Because maintenance of non-scalable cellular components--membranes and chromosomes--requires an increasing fraction of energy as cell size decreases, miniaturization comes at a considerable energetic cost for a phytoplanktonic cell. Consequently, if eukaryotes can use their superior energetic resources to acquire nutrients with more or even similar efficiency compared with prokaryotes, larger unicellular eukaryotes should be able to achieve higher growth rates than smaller cyanobacteria. Here, to test this hypothesis, we directly compare the intrinsic growth rates of phototrophic prokaryotes and eukaryotes from the equatorial to temperate South Atlantic using an original flow cytometric (14)CO2-tracer approach. At the ocean basin scale, cyanobacteria double their biomass twice as frequently as the picoeukaryotes indicating that the prokaryotes are faster growing CO2 fixers, better adapted to phototrophic living in the oligotrophic open ocean-the most extensive biome on Earth.

  19. Drought evolution: greater and faster impacts on blue water than on green water (United States)

    Destouni, G.; Orth, R.


    Drought propagates through the terrestrial water cycle, affecting different interlinked geospheres which have so far been mostly investigated separately and without direct comparison. By use of comprehensive multi-decadal data from >400 near-natural catchments along a steep climate gradient across Europe we here analyze drought propagation from precipitation (deficits) through soil moisture to runoff (blue water) and evapotranspiration (green water). We show that soil-moisture droughts reduce runoff stronger and faster than evapotranspiration. While runoff responds within weeks, evapotranspiration can be unaffected for months, or even entirely as in central and northern Europe. Understanding these different drought pathways towards blue and green water resources contributes to improve food and water security and offers early warning potential to mitigate (future) drought impacts on society and ecosystems.

  20. Capacity at Railway Stations

    DEFF Research Database (Denmark)

    Landex, Alex


    zone(s) the possible conflicts with other trains (also in the opposite direction) are taken into account leading to more trustworthy results. Although the UIC 406 methodology proposes that the railway network should be divided into line sections when trains turn around and when the train order...... is changed, this paper recommends that the railway lines are not always be divided. In case trains turn around on open (single track) line, the capacity consumption may be too low if a railway line is divided. The same can be the case if only few trains are overtaken at an overtaking station. For dead end......Stations do have other challenges regarding capacity than open lines as it is here the traffic is dispatched. The UIC 406 capacity method that can be used to analyse the capacity consumption can be exposed in different ways at stations which may lead to different results. Therefore, stations need...

  1. Visual attention capacity

    DEFF Research Database (Denmark)

    Habekost, Thomas; Starrfelt, Randi


    Psychophysical studies have identified two distinct limitations of visual attention capacity: processing speed and apprehension span. Using a simple test, these cognitive factors can be analyzed by Bundesen's Theory of Visual Attention (TVA). The method has strong specificity and sensitivity...

  2. The Development of Functional Overreaching Is Associated with a Faster Heart Rate Recovery in Endurance Athletes. (United States)

    Aubry, Anaël; Hausswirth, Christophe; Louis, Julien; Coutts, Aaron J; Buchheit, Martin; Le Meur, Yann


    The aim of the study was to investigate whether heart rate recovery (HRR) may represent an effective marker of functional overreaching (f-OR) in endurance athletes. Thirty-one experienced male triathletes were tested (10 control and 21 overload subjects) before (Pre), and immediately after an overload training period (Mid) and after a 2-week taper (Post). Physiological responses were assessed during an incremental cycling protocol to exhaustion, including heart rate, catecholamine release and blood lactate concentration. Ten participants from the overload group developed signs of f-OR at Mid (i.e. -2.1 ± 0.8% change in performance associated with concomitant high perceived fatigue). Additionally, only the f-OR group demonstrated a 99% chance of increase in HRR during the overload period (+8 ± 5 bpm, large effect size). Concomitantly, this group also revealed a >80% chance of decreasing blood lactate (-11 ± 14%, large), plasma norepinephrine (-12 ± 37%, small) and plasma epinephrine peak concentrations (-51 ± 22%, moderate). These blood measures returned to baseline levels at Post. HRR change was negatively correlated to changes in performance, peak HR and peak blood metabolites concentrations. These findings suggest that i) a faster HRR is not systematically associated with improved physical performance, ii) changes in HRR should be interpreted in the context of the specific training phase, the athletes perceived level of fatigue and the performance response; and, iii) the faster HRR associated with f-OR may be induced by a decreased central command and by a lower chemoreflex activity.

  3. Canalith repositioning in apogeotropic horizontal canal benign paroxysmal positional vertigo: Do we need faster maneuvering? (United States)

    Hwang, Minho; Kim, Sang-Hoon; Kang, Kyung-Wook; Lee, Dasom; Lee, Sae-Young; Kim, Myeong-Kyu; Lee, Seung-Han


    A correct diagnosis and a proper treatment may yield a rapid and simple cure for benign paroxysmal positional vertigo (BPPV). Although the Gufoni maneuver is widely used to treat apogeotropic horizontal-canal BPPV (HC-BPPV), few studies have clarified the relationship between the speed and intensity of maneuver execution and successful canalith reposition. To evaluate the effect of accelerated execution of the Gufoni maneuver, a prospective randomized controlled study was conducted with HC-BPPV patients in a single dizziness clinic. The patients had been diagnosed with apogeotropic HC-BPPV and were undergoing treatment at the dizziness clinic of a tertiary university hospital from January 2013 to August 2014. Two groups were treated with the maneuver performed at different speeds and the resolution rate was compared. The accelerated maneuver group was subjected to faster position changing-within 1s-during the reposition maneuver, while the non-accelerated maneuver group underwent slower maneuvers. Therapeutic efficacy was defined as dizziness relief or resolution of nystagmus within 1h. Fifty patients with apogeotropic HC-BPPV were enrolled and treated with the Gufoni maneuver in two groups of 25 patients. The overall resolution rate was 48% (24 of 50; p=1.00), regardless of acceleration. Our results suggest that a faster, more intense execution of the Gufoni maneuver provides little benefit in treating apogeotropic HC-BPPV. Detachment of the otolith from the cupula or the gravitational force-when the otolith is in the anterior arm of the HC-may be more important contributors to treatment efficacy. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. The Development of Functional Overreaching Is Associated with a Faster Heart Rate Recovery in Endurance Athletes (United States)

    Aubry, Anaël; Hausswirth, Christophe; Louis, Julien; Coutts, Aaron J.


    Purpose The aim of the study was to investigate whether heart rate recovery (HRR) may represent an effective marker of functional overreaching (f-OR) in endurance athletes. Methods and Results Thirty-one experienced male triathletes were tested (10 control and 21 overload subjects) before (Pre), and immediately after an overload training period (Mid) and after a 2-week taper (Post). Physiological responses were assessed during an incremental cycling protocol to exhaustion, including heart rate, catecholamine release and blood lactate concentration. Ten participants from the overload group developed signs of f-OR at Mid (i.e. -2.1 ± 0.8% change in performance associated with concomitant high perceived fatigue). Additionally, only the f-OR group demonstrated a 99% chance of increase in HRR during the overload period (+8 ± 5 bpm, large effect size). Concomitantly, this group also revealed a >80% chance of decreasing blood lactate (-11 ± 14%, large), plasma norepinephrine (-12 ± 37%, small) and plasma epinephrine peak concentrations (-51 ± 22%, moderate). These blood measures returned to baseline levels at Post. HRR change was negatively correlated to changes in performance, peak HR and peak blood metabolites concentrations. Conclusion These findings suggest that i) a faster HRR is not systematically associated with improved physical performance, ii) changes in HRR should be interpreted in the context of the specific training phase, the athletes perceived level of fatigue and the performance response; and, iii) the faster HRR associated with f-OR may be induced by a decreased central command and by a lower chemoreflex activity. PMID:26488766

  5. Faster but not smarter: effects of caffeine and caffeine withdrawal on alertness and performance. (United States)

    Rogers, Peter J; Heatherley, Susan V; Mullings, Emma L; Smith, Jessica E


    Despite 100 years of psychopharmacological research, the extent to which caffeine consumption benefits human functioning remains unclear. To measure the effects of overnight caffeine abstinence and caffeine administration as a function of level of habitual caffeine consumption. Medium-high (n = 212) and non-low (n = 157) caffeine consumers completed self-report measures and computer-based tasks before (starting at 10:30 AM) and after double-blind treatment with either caffeine (100 mg, then 150 mg) or placebo. The first treatment was given at 11:15 AM and the second at 12:45 PM, with post-treatment measures repeated twice between 1:45 PM and 3:30 PM. Caffeine withdrawal was associated with some detrimental effects at 10:30 AM, and more severe effects, including greater sleepiness, lower mental alertness, and poorer performance on simple reaction time, choice reaction time and recognition memory tasks, later in the afternoon. Caffeine improved these measures in medium-high consumers but, apart from decreasing sleepiness, had little effect on them in non-low consumers. The failure of caffeine to increase mental alertness and improve mental performance in non-low consumers was related to a substantial caffeine-induced increase in anxiety/jitteriness that offset the benefit of decreased sleepiness. Caffeine enhanced physical performance (faster tapping speed and faster simple and choice reaction times) in both medium-high and non-low consumers. While caffeine benefits motor performance and tolerance develops to its tendency to increase anxiety/jitteriness, tolerance to its effects on sleepiness means that frequent consumption fails to enhance mental alertness and mental performance.

  6. Faster Movement Speed Results in Greater Tendon Strain during the Loaded Squat Exercise. (United States)

    Earp, Jacob E; Newton, Robert U; Cormie, Prue; Blazevich, Anthony J


    Tendon dynamics influence movement performance and provide the stimulus for long-term tendon adaptation. As tendon strain increases with load magnitude and decreases with loading rate, changes in movement speed during exercise should influence tendon strain. Ten resistance-trained men [squat one repetition maximum (1RM) to body mass ratio: 1.65 ± 0.12] performed parallel-depth back squat lifts with 60% of 1RM load at three different speeds: slow fixed-tempo (TS: 2-s eccentric, 1-s pause, 2-s concentric), volitional-speed without a pause (VS) and maximum-speed jump (JS). In each condition joint kinetics, quadriceps tendon length (LT), patellar tendon force (FT), and rate of force development (RFDT) were estimated using integrated ultrasonography, motion-capture, and force platform recordings. Peak LT, FT, and RFDT were greater in JS than TS (p < 0.05), however no differences were observed between VS and TS. Thus, moving at faster speeds resulted in both greater tendon stress and strain despite an increased RFDT, as would be predicted of an elastic, but not a viscous, structure. Temporal comparisons showed that LT was greater in TS than JS during the early eccentric phase (10-14% movement duration) where peak RFDT occurred, demonstrating that the tendon's viscous properties predominated during initial eccentric loading. However, during the concentric phase (61-70 and 76-83% movement duration) differing FT and similar RFDT between conditions allowed for the tendon's elastic properties to predominate such that peak tendon strain was greater in JS than TS. Based on our current understanding, there may be an additional mechanical stimulus for tendon adaptation when performing large range-of-motion isoinertial exercises at faster movement speeds.

  7. The Development of Functional Overreaching Is Associated with a Faster Heart Rate Recovery in Endurance Athletes.

    Directory of Open Access Journals (Sweden)

    Anaël Aubry

    Full Text Available The aim of the study was to investigate whether heart rate recovery (HRR may represent an effective marker of functional overreaching (f-OR in endurance athletes.Thirty-one experienced male triathletes were tested (10 control and 21 overload subjects before (Pre, and immediately after an overload training period (Mid and after a 2-week taper (Post. Physiological responses were assessed during an incremental cycling protocol to exhaustion, including heart rate, catecholamine release and blood lactate concentration. Ten participants from the overload group developed signs of f-OR at Mid (i.e. -2.1 ± 0.8% change in performance associated with concomitant high perceived fatigue. Additionally, only the f-OR group demonstrated a 99% chance of increase in HRR during the overload period (+8 ± 5 bpm, large effect size. Concomitantly, this group also revealed a >80% chance of decreasing blood lactate (-11 ± 14%, large, plasma norepinephrine (-12 ± 37%, small and plasma epinephrine peak concentrations (-51 ± 22%, moderate. These blood measures returned to baseline levels at Post. HRR change was negatively correlated to changes in performance, peak HR and peak blood metabolites concentrations.These findings suggest that i a faster HRR is not systematically associated with improved physical performance, ii changes in HRR should be interpreted in the context of the specific training phase, the athletes perceived level of fatigue and the performance response; and, iii the faster HRR associated with f-OR may be induced by a decreased central command and by a lower chemoreflex activity.

  8. Faster Movement Speed Results in Greater Tendon Strain during the Loaded Squat Exercise (United States)

    Earp, Jacob E.; Newton, Robert U.; Cormie, Prue; Blazevich, Anthony J.


    Introduction: Tendon dynamics influence movement performance and provide the stimulus for long-term tendon adaptation. As tendon strain increases with load magnitude and decreases with loading rate, changes in movement speed during exercise should influence tendon strain. Methods: Ten resistance-trained men [squat one repetition maximum (1RM) to body mass ratio: 1.65 ± 0.12] performed parallel-depth back squat lifts with 60% of 1RM load at three different speeds: slow fixed-tempo (TS: 2-s eccentric, 1-s pause, 2-s concentric), volitional-speed without a pause (VS) and maximum-speed jump (JS). In each condition joint kinetics, quadriceps tendon length (LT), patellar tendon force (FT), and rate of force development (RFDT) were estimated using integrated ultrasonography, motion-capture, and force platform recordings. Results: Peak LT, FT, and RFDT were greater in JS than TS (p < 0.05), however no differences were observed between VS and TS. Thus, moving at faster speeds resulted in both greater tendon stress and strain despite an increased RFDT, as would be predicted of an elastic, but not a viscous, structure. Temporal comparisons showed that LT was greater in TS than JS during the early eccentric phase (10–14% movement duration) where peak RFDT occurred, demonstrating that the tendon's viscous properties predominated during initial eccentric loading. However, during the concentric phase (61–70 and 76–83% movement duration) differing FT and similar RFDT between conditions allowed for the tendon's elastic properties to predominate such that peak tendon strain was greater in JS than TS. Conclusions: Based on our current understanding, there may be an additional mechanical stimulus for tendon adaptation when performing large range-of-motion isoinertial exercises at faster movement speeds. PMID:27630574

  9. Revisiting Absorptive Capacity

    DEFF Research Database (Denmark)

    de Araújo, Ana Luiza Lara; Ulhøi, John Parm; Lettl, Christopher

    learning processes of absorptive capacity, which comprise combinative and adaptive capabilities. Drawing on survey data (n=169), the study concludes that combinative capabilities primarily enhance transformative and exploratory learning processes, while adaptive capabilities strengthen all three learning......Absorptive capacity has mostly been perceived as a 'passive' outcome of R&D investments. Recently, however, a growing interest into its 'proactive' potentials has emerged. This paper taps into this development and proposes a dynamic model for conceptualizing the determinants of the complementary...

  10. Performance evaluation of a wavy-fin heat sink for power electronics

    International Nuclear Information System (INIS)

    Lorenzini, Marco; Fabbri, Giampietro; Salvigni, Sandro


    The almost daily increase in dissipated power per unit area of electronic components sets higher and higher demands on the performance of the heat sinks. These must not only be able to dissipate high heat fluxes, but must also keep costs to a minimum and exhibit a reliable behaviour. In this paper a novel, modular heat sink consisting of elements with wavy fin profile which can be pressed together to construct the component is presented. Its performance under steady-state conditions are assessed for the case of forced convection in terms of velocity distribution in the channels and global thermal resistance. Configurations with uniform and non-uniform heat flux are studied and some considerations are made as to the influence of the spacers between fan and heat sink proper

  11. Fluid motion and solute distribution around sinking aggregates II : Implications for remote detection by colonizing zooplankters

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Thygesen, Uffe Høgsbro


    to account for the observed abundances of colonizers. We next solved the advection-diffusion equation to describe the chemical trail left by a leaking and sinking aggregate. The plume is long and slender and may be detected by a horizontally cruising copepod. From the model of the plume and literature- based......Marine snow aggregates are colonized by copepods, and encounter rates inferred from observed abundances of colonizers are high. We examined the potential for hydromechanical and chemical remote detection. The fluid disturbance generated by a sinking aggregate was described by solving the Navier......-Stokes' equation for a sinking sphere at Reynolds numbers typical of marine snow (up to 20). Fluid deformation rate, the component of the flow that can be perceived by copepods, attenuates rapidly, and detection distances estimated from knowledge of the hydromechanical sensitivity in copepods are insufficient...

  12. Enhancing ultra-high CPV passive cooling using least-material finned heat sinks

    International Nuclear Information System (INIS)

    Micheli, Leonardo; Mallick, Tapas K.; Fernandez, Eduardo F.; Almonacid, Florencia; Reddy, K. S.


    Ultra-high concentrating photovoltaic (CPV) systems aim to increase the cost-competiveness of CPV by increasing the concentrations over 2000 suns. In this work, the design of a heat sink for ultra-high concentrating photovoltaic (CPV) applications is presented. For the first time, the least-material approach, widely used in electronics to maximize the thermal dissipation while minimizing the weight of the heat sink, has been applied in CPV. This method has the potential to further decrease the cost of this technology and to keep the multijunction cell within the operative temperature range. The designing procedure is described in the paper and the results of a thermal simulation are shown to prove the reliability of the solution. A prediction of the costs is also reported: a cost of 0.151$/W p is expected for a passive least-material heat sink developed for 4000x applications

  13. Topology optimization of a pseudo 3D thermofluid heat sink model

    DEFF Research Database (Denmark)

    Haertel, Jan H. K.; Engelbrecht, Kurt; Lazarov, Boyan S.


    This paper investigates the application of density-based topology optimization to the design of air-cooled forced convection heat sinks. To reduce the computational burden that is associated with a full 3D optimization, a pseudo 3D optimization model comprising a 2D modeled conducting metal base...... sink and a fixed heat production rate in the base plate. Optimized designs are presented and the resulting fin geometry is discussed from a thermal engineering point of view and compared to fin shapes resulting from a pressure drop minimization objective. Parametric studies are conducted to analyze...... is found, confirming the physical validity of the utilized optimization model. Two topology optimized designs are exemplarily benchmarked against a size optimized parallel fin heat sink and an up to 13.6% lower thermal resistance is found to be realized by the topology optimization....

  14. Enhancing ultra-high CPV passive cooling using least-material finned heat sinks (United States)

    Micheli, Leonardo; Fernandez, Eduardo F.; Almonacid, Florencia; Reddy, K. S.; Mallick, Tapas K.


    Ultra-high concentrating photovoltaic (CPV) systems aim to increase the cost-competiveness of CPV by increasing the concentrations over 2000 suns. In this work, the design of a heat sink for ultra-high concentrating photovoltaic (CPV) applications is presented. For the first time, the least-material approach, widely used in electronics to maximize the thermal dissipation while minimizing the weight of the heat sink, has been applied in CPV. This method has the potential to further decrease the cost of this technology and to keep the multijunction cell within the operative temperature range. The designing procedure is described in the paper and the results of a thermal simulation are shown to prove the reliability of the solution. A prediction of the costs is also reported: a cost of 0.151/Wp is expected for a passive least-material heat sink developed for 4000x applications.

  15. A Type of Low-Latency Data Gathering Method with Multi-Sink for Sensor Networks

    Directory of Open Access Journals (Sweden)

    Chao Sha


    Full Text Available To balance energy consumption and reduce latency on data transmission in Wireless Sensor Networks (WSNs, a type of low-latency data gathering method with multi-Sink (LDGM for short is proposed in this paper. The network is divided into several virtual regions consisting of three or less data gathering units and the leader of each region is selected according to its residual energy as well as distance to all of the other nodes. Only the leaders in each region need to communicate with the mobile Sinks which have effectively reduced energy consumption and the end-to-end delay. Moreover, with the help of the sleep scheduling and the sensing radius adjustment strategies, redundancy in network coverage could also be effectively reduced. Simulation results show that LDGM is energy efficient in comparison with MST as well as MWST and its time efficiency on data collection is higher than one Sink based data gathering methods.

  16. Anaerobic nitrogen turnover by sinking diatom aggregates at varying ambient oxygen levels

    DEFF Research Database (Denmark)

    Stief, Peter; Kamp, Anja; Thamdrup, Bo


    In the world’s oceans, even relatively low oxygen levels inhibit anaerobic nitrogen cycling by free-living microbes. Sinking organic aggregates, however, might provide oxygen-depleted microbial hotspots in otherwise oxygenated surface waters. Here, we show that sinking diatom aggregates can host...... anaerobic nitrogen cycling at ambient oxygen levels well above the hypoxic threshold. Aggregates were produced from the ubiquitous diatom Skeletonema marinoi and the natural microbial community of seawater. Microsensor profiling through the center of sinking aggregates revealed internal anoxia at ambient 40......% air saturation (∼100 μmol O2 L-1) and below. Accordingly, anaerobic nitrate turnover inside the aggregates was evident within this range of ambient oxygen levels. In incubations with 15N-labeled nitrate, individual Skeletonema aggregates produced NO2- (up to 10.7 nmol N h-1 per aggregate), N2 (up to 7...

  17. Spatial variation in anthropogenic mortality induces a source-sink system in a hunted mesopredator. (United States)

    Minnie, Liaan; Zalewski, Andrzej; Zalewska, Hanna; Kerley, Graham I H


    Lethal carnivore management is a prevailing strategy to reduce livestock predation. Intensity of lethal management varies according to land-use, where carnivores are more intensively hunted on farms relative to reserves. Variations in hunting intensity may result in the formation of a source-sink system where carnivores disperse from high-density to low-density areas. Few studies quantify dispersal between supposed sources and sinks-a fundamental requirement for source-sink systems. We used the black-backed jackal (Canis mesomelas) as a model to determine if heterogeneous anthropogenic mortality induces a source-sink system. We analysed 12 microsatellite loci from 554 individuals from lightly hunted and previously unhunted reserves, as well as heavily hunted livestock- and game farms. Bayesian genotype assignment showed that jackal populations displayed a hierarchical population structure. We identified two genetically distinct populations at the regional level and nine distinct subpopulations at the local level, with each cluster corresponding to distinct land-use types separated by various dispersal barriers. Migration, estimated using Bayesian multilocus genotyping, between reserves and farms was asymmetric and heterogeneous anthropogenic mortality induced source-sink dynamics via compensatory immigration. Additionally some heavily hunted populations also acted as source populations, exporting individuals to other heavily hunted populations. This indicates that heterogeneous anthropogenic mortality results in the formation of a complex series of interconnected sources and sinks. Thus, lethal management of mesopredators may not be an effective long-term strategy in reducing livestock predation, as dispersal and, more importantly, compensatory immigration may continue to affect population reduction efforts as long as dispersal from other areas persists.

  18. A multispecies test of source-sink indicators to prioritize habitat for declining populations. (United States)

    Heinrichs, Julie A; Lawler, Joshua J; Schumaker, Nathan H; Wilsey, Chad B; Monroe, Kira C; Aldridge, Cameron L


    For species at risk of decline or extinction in source-sink systems, sources are an obvious target for habitat protection actions. However, the way in which source habitats are identified and prioritized can reduce the effectiveness of conservation actions. Although sources and sinks are conceptually defined using both demographic and movement criteria, simplifications are often required in systems with limited data. To assess the conservation outcomes of alternative source metrics and resulting prioritizations, we simulated population dynamics and extinction risk for 3 endangered species. Using empirically based habitat population models, we linked habitat maps with measured site- or habitat-specific demographic conditions, movement abilities, and behaviors. We calculated source-sink metrics over a range of periods of data collection and prioritized consistently high-output sources for conservation. We then tested whether prioritized patches identified the habitats that most affected persistence by removing them and measuring the population response. Conservation decisions based on different source-sink metrics and durations of data collection affected species persistence. Shorter time series obscured the ability of metrics to identify influential habitats, particularly in temporally variable and slowly declining populations. Data-rich source-sink metrics that included both demography and movement information did not always identify the habitats with the greatest influence on extinction risk. In some declining populations, patch abundance better predicted influential habitats for short-term regional persistence. Because source-sink metrics (i.e., births minus deaths; births and immigrations minus deaths and emigration) describe net population conditions and cancel out gross population counts, they may not adequately identify influential habitats in declining populations. For many nonequilibrium populations, new metrics that maintain the counts of individual births

  19. A numerical method for PCM-based pin fin heat sinks optimization

    International Nuclear Information System (INIS)

    Pakrouh, R.; Hosseini, M.J.; Ranjbar, A.A.; Bahrampoury, R.


    Highlights: • Optimization of PCM-based heat sink by using the Taguchi method. • Derivation of optimal PCM percentage to reach the maximum critical time. • Optimization is performed for four different critical temperatures. • Effective design factors are fins’ height and fins’ number. • The optimum configuration depends on geometric properties and the critical temperature. - Abstract: This paper presents a numerical investigation on geometric optimization of PCM-based pin fin heat sinks. Paraffin RT44HC is used as PCM while the fins and heat sink base is made of aluminum. The fins act as thermal conductivity enhancers (TCEs). The main goal of the study is to obtain the configurations that maximize the heat sink operational time. An approach witch couples Taguchi method with numerical simulations is utilized for this purpose. Number of fins, fins height, fins thickness and the base thickness are parameters which are studied for optimization. In this study natural convection and PCM volume variation during melting process are considered in the simulations. Optimization is performed for different critical temperatures of 50 °C, 60 °C, 70 °C and 80 °C. Results show that a complex relation exists between PCM and TCE volume percentages. The optimal case strongly depends on the fins’ number, fins’ height and thickness and also the critical temperature. The optimum PCM percentages are found to be 60.61% (corresponds to 100 pin fin heat sink with 4 mm thick fins) for critical temperature of 50 °C and 82.65% (corresponds to 100 pin fin heat sink with 2 mm thick fins) for other critical temperatures

  20. Experimental investigation of thermoelectric power generation versus coolant pumping power in a microchannel heat sink

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Rosendahl, Lasse; Andreasen, Søren Juhl


    The coolant heat sinks in thermoelectric generators (TEG) play an important role in order to power generation in the energy systems. This paper explores the effective pumping power required for the TEGs cooling at five temperature difference of the hot and cold sides of the TEG. In addition......, the temperature distribution and the pressure drop in sample microchannels are considered at four sample coolant flow rates. The heat sink contains twenty plate-fin microchannels with hydraulic diameter equal to 0.93 mm. The experimental results show that there is a unique flow rate that gives maximum net...

  1. Pitch-based carbon foam heat sink with phase change material (United States)

    Klett, James W.; Burchell, Timothy D.


    A process for producing a carbon foam heat sink is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications. The foam is encased and filled with a phase change material to provide a very efficient heat sink device.

  2. When high-capacity readers slow down and low-capacity readers speed up: Working memory and locality effects

    Directory of Open Access Journals (Sweden)

    Bruno eNicenboim


    Full Text Available We examined the effects of argument-head distance in SVO and SOV languages (Spanish and German, while taking into account readers’ working memory capacity and controlling for expectation (Levy, 2008 and other factors. We predicted only locality effects, that is, a slow-down produced by increased dependency distance (Gibson, 2000; Lewis & Vasishth, 2005. Furthermore, we expected stronger locality effects for readers with low working memory capacity. Contrary to our predictions, low-capacity readers showed faster reading with increased distance, while high-capacity readers showed locality effects. We suggest that while the locality effects are compatible with memory-based explanations, the speedup of low-capacity readers can be explained by an increased probability of retrieval failure. We present a computational model based on ACT-R built under the previous assumptions, which is able to give a qualitative account for the present data and can be tested in future research. Our results suggest that in some cases, interpreting longer RTs as indexing increased processing difficulty and shorter RTs as facilitation may be too simplistic: The same increase in processing difficulty may lead to slowdowns in high-capacity readers and speedups in low-capacity ones. Ignoring individual level capacity differences when investigating locality effects may lead to misleading conclusions.

  3. Maintenance of C sinks sustains enhanced C assimilation during long-term exposure to elevated [CO2] in Mojave Desert shrubs. (United States)

    Aranjuelo, Iker; Ebbets, Allison L; Evans, R Dave; Tissue, David T; Nogués, Salvador; van Gestel, Natasja; Payton, Paxton; Ebbert, Volker; Adams, Williams W; Nowak, Robert S; Smith, Stanley D


    During the first few years of elevated atmospheric [CO(2)] treatment at the Nevada Desert FACE Facility, photosynthetic downregulation was observed in desert shrubs grown under elevated [CO(2)], especially under relatively wet environmental conditions. Nonetheless, those plants maintained increased A (sat) (photosynthetic performance at saturating light and treatment [CO(2)]) under wet conditions, but to a much lesser extent under dry conditions. To determine if plants continued to downregulate during long-term exposure to elevated [CO(2)], responses of photosynthesis to elevated [CO(2)] were examined in two dominant Mojave Desert shrubs, the evergreen Larrea tridentata and the drought-deciduous Ambrosia dumosa, during the eighth full growing season of elevated [CO(2)] treatment at the NDFF. A comprehensive suite of physiological processes were collected. Furthermore, we used C labeling of air to assess carbon allocation and partitioning as measures of C sink activity. Results show that elevated [CO(2)] enhanced photosynthetic performance and plant water status in Larrea, especially during periods of environmental stress, but not in Ambrosia. δ(13)C analyses indicate that Larrea under elevated [CO(2)] allocated a greater proportion of newly assimilated C to C sinks than Ambrosia. Maintenance by Larrea of C sinks during the dry season partially explained the reduced [CO(2)] effect on leaf carbohydrate content during summer, which in turn lessened carbohydrate build-up and feedback inhibition of photosynthesis. δ(13)C results also showed that in a year when plant growth reached the highest rates in 5 years, 4% (Larrea) and 7% (Ambrosia) of C in newly emerging organs were remobilized from C that was assimilated and stored for at least 2 years prior to the current study. Thus, after 8 years of continuous exposure to elevated [CO(2)], both desert perennials maintained their photosynthetic capacities under elevated [CO(2)]. We conclude that C storage, remobilization

  4. Measuring Greenhouse Gas Emissions and Sinks Across California Land Cover (United States)

    Fischer, M. L.


    Significant reductions in greenhouse gas (GHG) emissions are needed to limit rising planetary temperatures that will otherwise limit Earth's capacity to support life, introducing geopolitical instability. To help mitigate this threat, California has legislated landmark reductions in state-level greenhouse gas (GHG) emissions that set an example for broader action. Beginning with relatively assured reduction of current emissions to 1990 levels by 2020, future goals are much more challenging with 40% and 80% reductions below 1990 emissions by 2030 and 2050, respectively. While the majority of the reductions must focus on fossil fuels, inventory estimates of non-CO2 GHG emissions (i.e., CH4, N2O, and industrial compounds) constitute 15% of the total, suggesting reductions are required across multiple land use sectors. However, recent atmospheric inversion studies show methane and nitrous oxide (CH4 & N2O) emissions exceed current inventory estimates by factors of 1.2-1.8 and 1.6-2.6 (at 95% confidence), respectively, perhaps constituting up to 30% of State total emissions. The discrepancy is likely because current bottom-up models used for inventories do not accurately capture important management or biophysical factors. In the near term, process level experiments and sector-specific inversions are being planned to quantify the factors controlling non-CO2 GHG emissions for several of the dominant emission sectors. For biosphere carbon, California forests lands, which also depend on the combination of management, climate, and weather, lost above ground carbon from 2001-2010, and may be expected to lose soil and root carbon as a longer-term result. Here, it is important to identify and apply the best principles in forestry and agriculture to increase carbon stocks in depleted forest and agricultural areas, focusing on approaches that provide resilience to future climate and weather variations. Taken together, improved atmospheric, plant, and soil observations, together

  5. Faster algorithms for RNA-folding using the Four-Russians method. (United States)

    Venkatachalam, Balaji; Gusfield, Dan; Frid, Yelena


    The secondary structure that maximizes the number of non-crossing matchings between complimentary bases of an RNA sequence of length n can be computed in O(n3) time using Nussinov's dynamic programming algorithm. The Four-Russians method is a technique that reduces the running time for certain dynamic programming algorithms by a multiplicative factor after a preprocessing step where solutions to all smaller subproblems of a fixed size are exhaustively enumerated and solved. Frid and Gusfield designed an O(n3logn) algorithm for RNA folding using the Four-Russians technique. In their algorithm the preprocessing is interleaved with the algorithm computation. We simplify the algorithm and the analysis by doing the preprocessing once prior to the algorithm computation. We call this the two-vector method. We also show variants where instead of exhaustive preprocessing, we only solve the subproblems encountered in the main algorithm once and memoize the results. We give a simple proof of correctness and explore the practical advantages over the earlier method.The Nussinov algorithm admits an O(n2) time parallel algorithm. We show a parallel algorithm using the two-vector idea that improves the time bound to O(n2logn). We have implemented the parallel algorithm on graphics processing units using the CUDA platform. We discuss the organization of the data structures to exploit coalesced memory access for fast running times. The ideas to organize the data structures also help in improving the running time of the serial algorithms. For sequences of length up to 6000 bases the parallel algorithm takes only about 2.5 seconds and the two-vector serial method takes about 57 seconds on a desktop and 15 seconds on a server. Among the serial algorithms, the two-vector and memoized versions are faster than the Frid-Gusfield algorithm by a factor of 3, and are faster than Nussinov by up to a factor of 20. The source-code for the algorithms is available at

  6. Faster than classical quantum algorithm for dense formulas of exact satisfiability and occupation problems (United States)

    Mandrà, Salvatore; Giacomo Guerreschi, Gian; Aspuru-Guzik, Alán


    We present an exact quantum algorithm for solving the Exact Satisfiability problem, which belongs to the important NP-complete complexity class. The algorithm is based on an intuitive approach that can be divided into two parts: the first step consists in the identification and efficient characterization of a restricted subspace that contains all the valid assignments of the Exact Satisfiability; while the second part performs a quantum search in such restricted subspace. The quantum algorithm can be used either to find a valid assignment (or to certify that no solution exists) or to count the total number of valid assignments. The query complexities for the worst-case are respectively bounded by O(\\sqrt{{2}n-{M\\prime }}) and O({2}n-{M\\prime }), where n is the number of variables and {M}\\prime the number of linearly independent clauses. Remarkably, the proposed quantum algorithm results to be faster than any known exact classical algorithm to solve dense formulas of Exact Satisfiability. As a concrete application, we provide the worst-case complexity for the Hamiltonian cycle problem obtained after mapping it to a suitable Occupation problem. Specifically, we show that the time complexity for the proposed quantum algorithm is bounded by O({2}n/4) for 3-regular undirected graphs, where n is the number of nodes. The same worst-case complexity holds for (3,3)-regular bipartite graphs. As a reference, the current best classical algorithm has a (worst-case) running time bounded by O({2}31n/96). Finally, when compared to heuristic techniques for Exact Satisfiability problems, the proposed quantum algorithm is faster than the classical WalkSAT and Adiabatic Quantum Optimization for random instances with a density of constraints close to the satisfiability threshold, the regime in which instances are typically the hardest to solve. The proposed quantum algorithm can be straightforwardly extended to the generalized version of the Exact Satisfiability known as Occupation

  7. Terrestrial Carbon Sinks in the Brazilian Amazon and Cerrado Region Predicted from MODIS Satellite Data and Ecosystem Modeling (United States)

    Potter, C.; Klooster, S.; Huete, A.; Genovese, V.; Bustamante, M.; Ferreira, L. Guimaraes; deOliveira, R. C., Jr.; Zepp, R.


    A simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000-2004. Net ecosystem production (NEP) flux for atmospheric CO2 in the region for these years was estimated. Consistently high carbon sink fluxes in terrestrial ecosystems on a yearly basis were found in the western portions of the states of Acre and Rondonia and the northern portions of the state of Par a. These areas were not significantly impacted by the 2002-2003 El Nino event in terms of net annual carbon gains. Areas of the region that show periodically high carbon source fluxes from terrestrial ecosystems to the atmosphere on yearly basis were found throughout the state of Maranhao and the southern portions of the state of Amazonas. As demonstrated though tower site comparisons, NEP modeled with monthly MODIS Enhanced Vegetation Index (EVI) inputs closely resembles the measured seasonal carbon fluxes at the LBA Tapajos tower site. Modeling results suggest that the capacity for use of MODIS Enhanced Vegetation Index (EVI) data to predict seasonal uptake rates of CO2 in Amazon forests and Cerrado woodlands is strong.

  8. Terrestrial carbon sinks in the Brazilian Amazon and Cerrado region predicted from MODIS satellite data and ecosystem modeling

    Directory of Open Access Journals (Sweden)

    C. Potter


    Full Text Available A simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000–2004. Net ecosystem production (NEP flux for atmospheric CO2 in the region for these years was estimated. Consistently high carbon sink fluxes in terrestrial ecosystems on a yearly basis were found in the western portions of the states of Acre and Rondônia and the northern portions of the state of Pará. These areas were not significantly impacted by the 2002–2003 El Niño event in terms of net annual carbon gains. Areas of the region that show periodically high carbon source fluxes from terrestrial ecosystems to the atmosphere on yearly basis were found throughout the state of Maranhão and the southern portions of the state of Amazonas. As demonstrated though tower site comparisons, NEP modeled with monthly MODIS Enhanced Vegetation Index (EVI inputs closely resembles the measured seasonal carbon fluxes at the LBA Tapajos tower site. Modeling results suggest that the capacity for use of MODIS Enhanced Vegetation Index (EVI data to predict seasonal uptake rates of CO2 in Amazon forests and Cerrado woodlands is strong.

  9. Weather and road capacity

    DEFF Research Database (Denmark)

    Jensen, Thomas Christian


    The paper presents estimations of the effect of bad weather on the observed speed on a Danish highway section; Køge Bugt Motorvejen. The paper concludes that weather, primarily precipitation and snow, has a clear negative effect on speed when the road is not in hypercongestion mode. Furthermore......, the capacity of the highway seems to be reduced in bad weather and there are indications that travel time variability is also increased, at least in free-flow conditions. Heavy precipitation reduces speed and capacity by around 5-8%, whereas snow primarily reduces capacity. Other weather variables......-parametrically against traffic density and in step 2 the residuals from step 1 are regressed linearly against the weather variables. The choice of a non-parametric method is made to avoid constricting ties from a parametric specification and because the focus here is not on the relationship between traffic flow...

  10. Dual capacity reciprocating compressor (United States)

    Wolfe, Robert W.


    A multi-cylinder compressor 10 particularly useful in connection with northern climate heat pumps and in which different capacities are available in accordance with reversing motor 16 rotation is provided with an eccentric cam 38 on a crank pin 34 under a fraction of the connecting rods, and arranged for rotation upon the crank pin between opposite positions apart so that with cam rotation on the crank pin such that the crank throw is at its normal maximum value all pistons pump at full capacity, and with rotation of the crank shaft in the opposite direction the cam moves to a circumferential position on the crank pin such that the overall crank throw is zero. Pistons 24 whose connecting rods 30 ride on a crank pin 36 without a cam pump their normal rate with either crank rotational direction. Thus a small clearance volume is provided for any piston that moves when in either capacity mode of operation.

  11. Geothermal Plant Capacity Factors

    Energy Technology Data Exchange (ETDEWEB)

    Greg Mines; Jay Nathwani; Christopher Richard; Hillary Hanson; Rachel Wood


    The capacity factors recently provided by the Energy Information Administration (EIA) indicated this plant performance metric had declined for geothermal power plants since 2008. Though capacity factor is a term commonly used by geothermal stakeholders to express the ability of a plant to produce power, it is a term frequently misunderstood and in some instances incorrectly used. In this paper we discuss how this capacity factor is defined and utilized by the EIA, including discussion on the information that the EIA requests from operations in their 923 and 860 forms that are submitted both monthly and annually by geothermal operators. A discussion is also provided regarding the entities utilizing the information in the EIA reports, and how those entities can misinterpret the data being supplied by the operators. The intent of the paper is to inform the facility operators as the importance of the accuracy of the data that they provide, and the implications of not providing the correct information.

  12. Value for railway capacity

    DEFF Research Database (Denmark)

    Sameni, Melody Khadem; Preston, John M.


    to analyze the efficiency of operators in transforming inputs of allocated capacity of infrastructure and franchise payments into valuable passenger service outputs while avoiding delays. By addressing operational and economic aspects of capacity utilization simultaneously, the paper deviates from existing...... DEA work on the economic efficiency of railways by considering a new combination of input-output that also incorporates quality of service. The constant and variable returns to scale models are applied to the case study of franchised passenger operators in Great Britain. The follow-up Tobit regression...

  13. Application-level technique for faster transmission of large images on the internet (United States)

    Long, L. Rodney; Berman, Lewis E.; Neve, Leif; Roy, Gautam; Thoma, George R.


    An application-level technique for improving the transmission rate of large files is described in this paper. Such techniques are important in areas such as telemedicine, where near-real-time delivery of large files such as digital images is a goal: end users may include specialist whose time is scarce and expensive, and timely access to the data may be necessary for effective clinical treatment. Faster delivery is also an enabling technology for accessing remote medial archives. In conventional TCP/IP transmission, data to be transmitted is sent down one logical communication channel. Our technique divided the data into segments; each segment is sent down its own channel, and the segments are reassembled into a copy of the original data at the receiving end. This technique has been implemented and tested in a client-server program using Berkeley Unix sockets, multiple independent process for channel control, and interprocess communication techniques to guarantee the receipt and correct reassembly of the transmitted data. Performance measurements have been made on several hundred Internet transmissions (including Arizona-to-Maryland transmissions) of 5-megabyte cervical x- ray images. Transmission time as a function of number of channels has been recorded, and a 3-fold improvement in transmission rate has been observed.

  14. Booze, Bars, and Bystander Behavior: People who Consumed Alcohol Help Faster in the Presence of Others.

    Directory of Open Access Journals (Sweden)

    Marco eVan Bommel


    Full Text Available People help each other less often and less quickly when bystanders are present. In this paper, we propose that alcohol consumption could attenuate or reverse this so-called bystander effect. Alcohol impairs people cognitively and perceptually, leading them to think less about the presence of others and behave less inhibited. Moreover, alcohol makes people more prone to see the benefits of helping and not the costs. To provide an initial test of these lines of reasoning, we invited visitors of bars in Amsterdam to join our study at a secluded spot at the bar. We manipulated bystander presence, and at the end of the study, we measured alcohol consumption. When participants took their seats, the experimenter dropped some items. We measured how many items were picked up and how quickly participants engaged in helping. Results revealed that alcohol did not influence the bystander effect in terms of the amount of help given. But importantly, it did influence the bystander effect in terms of response times: People who consumed alcohol actually came to aid faster in the presence of others.

  15. Resonant Drag Instabilities in protoplanetary disks: the streaming instability and new, faster-growing instabilities (United States)

    Squire, Jonathan; Hopkins, Philip F.


    We identify and study a number of new, rapidly growing instabilities of dust grains in protoplanetary disks, which may be important for planetesimal formation. The study is based on the recognition that dust-gas mixtures are generically unstable to a Resonant Drag Instability (RDI), whenever the gas, absent dust, supports undamped linear modes. We show that the "streaming instability" is an RDI associated with epicyclic oscillations; this provides simple interpretations for its mechanisms and accurate analytic expressions for its growth rates and fastest-growing wavelengths. We extend this analysis to more general dust streaming motions and other waves, including buoyancy and magnetohydrodynamic oscillations, finding various new instabilities. Most importantly, we identify the disk "settling instability," which occurs as dust settles vertically into the midplane of a rotating disk. For small grains, this instability grows many orders of magnitude faster than the standard streaming instability, with a growth rate that is independent of grain size. Growth timescales for realistic dust-to-gas ratios are comparable to the disk orbital period, and the characteristic wavelengths are more than an order of magnitude larger than the streaming instability (allowing the instability to concentrate larger masses). This suggests that in the process of settling, dust will band into rings then filaments or clumps, potentially seeding dust traps, high-metallicity regions that in turn seed the streaming instability, or even overdensities that coagulate or directly collapse to planetesimals.

  16. Revisit the faster-is-slower effect for an exit at a corner (United States)

    Chen, Jun Min; Lin, Peng; Wu, Fan Yu; Li Gao, Dong; Wang, Guo Yuan


    The faster-is-slower effect (FIS), which means that crowd at a high enough velocity could significantly increase the evacuation time to escape through an exit, is an interesting phenomenon in pedestrian dynamics. Such phenomenon had been studied widely and has been experimentally verified in different systems of discrete particles flowing through a centre exit. To experimentally validate this phenomenon by using people under high pressure is difficult due to ethical issues. A mouse, similar to a human, is a kind of self-driven and soft body creature with competitive behaviour under stressed conditions. Therefore, mice are used to escape through an exit at a corner. A number of repeated tests are conducted and the average escape time per mouse at different levels of stimulus are analysed. The escape times do not increase obviously with the level of stimulus for the corner exit, which is contrary to the experiment with the center exit. The experimental results show that the FIS effect is not necessary a universal law for any discrete system. The observation could help the design of buildings by relocating their exits to the corner in rooms to avoid the formation of FIS effect.

  17. Cheaper faster drug development validated by the repositioning of drugs against neglected tropical diseases. (United States)

    Williams, Kevin; Bilsland, Elizabeth; Sparkes, Andrew; Aubrey, Wayne; Young, Michael; Soldatova, Larisa N; De Grave, Kurt; Ramon, Jan; de Clare, Michaela; Sirawaraporn, Worachart; Oliver, Stephen G; King, Ross D


    There is an urgent need to make drug discovery cheaper and faster. This will enable the development of treatments for diseases currently neglected for economic reasons, such as tropical and orphan diseases, and generally increase the supply of new drugs. Here, we report the Robot Scientist 'Eve' designed to make drug discovery more economical. A Robot Scientist is a laboratory automation system that uses artificial intelligence (AI) techniques to discover scientific knowledge through cycles of experimentation. Eve integrates and automates library-screening, hit-confirmation, and lead generation through cycles of quantitative structure activity relationship learning and testing. Using econometric modelling we demonstrate that the use of AI to select compounds economically outperforms standard drug screening. For further efficiency Eve uses a standardized form of assay to compute Boolean functions of compound properties. These assays can be quickly and cheaply engineered using synthetic biology, enabling more targets to be assayed for a given budget. Eve has repositioned several drugs against specific targets in parasites that cause tropical diseases. One validated discovery is that the anti-cancer compound TNP-470 is a potent inhibitor of dihydrofolate reductase from the malaria-causing parasite Plasmodium vivax.

  18. Faster acquisition of laparoscopic skills in virtual reality with haptic feedback and 3D vision. (United States)

    Hagelsteen, Kristine; Langegård, Anders; Lantz, Adam; Ekelund, Mikael; Anderberg, Magnus; Bergenfelz, Anders


    The study investigated whether 3D vision and haptic feedback in combination in a virtual reality environment leads to more efficient learning of laparoscopic skills in novices. Twenty novices were allocated to two groups. All completed a training course in the LapSim ® virtual reality trainer consisting of four tasks: 'instrument navigation', 'grasping', 'fine dissection' and 'suturing'. The study group performed with haptic feedback and 3D vision and the control group without. Before and after the LapSim ® course, the participants' metrics were recorded when tying a laparoscopic knot in the 2D video box trainer Simball ® Box. The study group completed the training course in 146 (100-291) minutes compared to 215 (175-489) minutes in the control group (p = .002). The number of attempts to reach proficiency was significantly lower. The study group had significantly faster learning of skills in three out of four individual tasks; instrument navigation, grasping and suturing. Using the Simball ® Box, no difference in laparoscopic knot tying after the LapSim ® course was noted when comparing the groups. Laparoscopic training in virtual reality with 3D vision and haptic feedback made training more time efficient and did not negatively affect later video box-performance in 2D. [Formula: see text].

  19. Faster family-wise error control for neuroimaging with a parametric bootstrap. (United States)

    Vandekar, Simon N; Satterthwaite, Theodore D; Rosen, Adon; Ciric, Rastko; Roalf, David R; Ruparel, Kosha; Gur, Ruben C; Gur, Raquel E; Shinohara, Russell T


    In neuroimaging, hundreds to hundreds of thousands of tests are performed across a set of brain regions or all locations in an image. Recent studies have shown that the most common family-wise error (FWE) controlling procedures in imaging, which rely on classical mathematical inequalities or Gaussian random field theory, yield FWE rates (FWER) that are far from the nominal level. Depending on the approach used, the FWER can be exceedingly small or grossly inflated. Given the widespread use of neuroimaging as a tool for understanding neurological and psychiatric disorders, it is imperative that reliable multiple testing procedures are available. To our knowledge, only permutation joint testing procedures have been shown to reliably control the FWER at the nominal level. However, these procedures are computationally intensive due to the increasingly available large sample sizes and dimensionality of the images, and analyses can take days to complete. Here, we develop a parametric bootstrap joint testing procedure. The parametric bootstrap procedure works directly with the test statistics, which leads to much faster estimation of adjusted p-values than resampling-based procedures while reliably controlling the FWER in sample sizes available in many neuroimaging studies. We demonstrate that the procedure controls the FWER in finite samples using simulations, and present region- and voxel-wise analyses to test for sex differences in developmental trajectories of cerebral blood flow. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail:

  20. Differentially-Expressed Genes Associated with Faster Growth of the Pacific Abalone, Haliotis discus hannai. (United States)

    Choi, Mi-Jin; Kim, Gun-Do; Kim, Jong-Myoung; Lim, Han Kyu


    The Pacific abalone Haliotis discus hannai is used for commercial aquaculture in Korea. We examined the transcriptome of Pacific abalone Haliotis discus hannai siblings using NGS technology to identify genes associated with high growth rates. Pacific abalones grown for 200 days post-fertilization were divided into small-, medium-, and large-size groups with mean weights of 0.26 ± 0.09 g, 1.43 ± 0.405 g, and 5.24 ± 1.09 g, respectively. RNA isolated from the soft tissues of each group was subjected to RNA sequencing. Approximately 1%-3% of the transcripts were differentially expressed in abalones, depending on the growth rate. RT-PCR was carried out on thirty four genes selected to confirm the relative differences in expression detected by RNA sequencing. Six differentially-expressed genes were identified as associated with faster growth of the Pacific abalone. These include five up-regulated genes (including one specific to females) encoding transcripts homologous to incilarin A, perlucin, transforming growth factor-beta-induced protein immunoglobulin-heavy chain 3 (ig-h3), vitelline envelope zona pellucida domain 4, and defensin, and one down-regulated gene encoding tomoregulin in large abalones. Most of the transcripts were expressed predominantly in the hepatopancreas. The genes identified in this study will lead to development of markers for identification of high-growth-rate abalones and female abalones.

  1. Gender, Social Networks, and Stroke Preparedness in the Stroke Warning Information and Faster Treatment Study. (United States)

    Madsen, Tracy E; Roberts, Eric T; Kuczynski, Heather; Goldmann, Emily; Parikh, Nina S; Boden-Albala, Bernadette


    The study aimed to investigate the effect of gender on the association between social networks and stroke preparedness as measured by emergency department (ED) arrival within 3 hours of symptom onset. As part of the Stroke Warning Information and Faster Treatment study, baseline data on demographics, social networks, and time to ED arrival were collected from 1193 prospectively enrolled stroke/transient ischemic attack (TIA) patients at Columbia University Medical Center. Logistic regression was conducted with arrival to the ED ≤3 hours as the outcome, social network characteristics as explanatory variables, and gender as a potential effect modifier. Men who lived alone or were divorced were significantly less likely to arrive ≤3 hours than men who lived with a spouse (adjusted odds ratio [aOR]: .31, 95% confidence interval [CI]: .15-0.64) or were married (aOR: .45, 95% CI: .23-0.86). Among women, those who lived alone or were divorced had similar odds of arriving ≤3 hours compared with those who lived with a spouse (aOR: 1.25, 95% CI: .63-2.49) or were married (aOR: .73, 95% CI: .4-1.35). In patients with stroke/TIA, living with someone or being married improved time to arrival in men only. Behavioral interventions to improve stroke preparedness should incorporate gender differences in how social networks affect arrival times. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  2. Development of Novel Faster-Dissolving Microneedle Patches for Transcutaneous Vaccine Delivery. (United States)

    Ono, Akihiko; Ito, Sayami; Sakagami, Shun; Asada, Hideo; Saito, Mio; Quan, Ying-Shu; Kamiyama, Fumio; Hirobe, Sachiko; Okada, Naoki


    Microneedle (MN) patches are promising for transcutaneous vaccination because they enable vaccine antigens to physically penetrate the stratum corneum via low-invasive skin puncturing, and to be effectively delivered to antigen-presenting cells in the skin. In second-generation MN patches, the dissolving MNs release the loaded vaccine antigen into the skin. To shorten skin application time for clinical practice, this study aims to develop novel faster-dissolving MNs. We designed two types of MNs made from a single thickening agent, carboxymethylcellulose (CMC) or hyaluronan (HN). Both CMC-MN and HN-MN completely dissolved in rat skin after a 5-min application. In pre-clinical studies, both MNs could demonstrably increase antigen-specific IgG levels after vaccination and prolong antigen deposition compared with conventional injections, and deliver antigens into resected human dermal tissue. In clinical research, we demonstrated that both MNs could reliably and safely puncture human skin without any significant skin irritation from transepidermal water loss measurements and ICDRG (International Contact Dermatitis Research Group) evaluation results.

  3. Processing language in face-to-face conversation: Questions with gestures get faster responses. (United States)

    Holler, Judith; Kendrick, Kobin H; Levinson, Stephen C


    The home of human language use is face-to-face interaction, a context in which communicative exchanges are characterised not only by bodily signals accompanying what is being said but also by a pattern of alternating turns at talk. This transition between turns is astonishingly fast-typically a mere 200-ms elapse between a current and a next speaker's contribution-meaning that comprehending, producing, and coordinating conversational contributions in time is a significant challenge. This begs the question of whether the additional information carried by bodily signals facilitates or hinders language processing in this time-pressured environment. We present analyses of multimodal conversations revealing that bodily signals appear to profoundly influence language processing in interaction: Questions accompanied by gestures lead to shorter turn transition times-that is, to faster responses-than questions without gestures, and responses come earlier when gestures end before compared to after the question turn has ended. These findings hold even after taking into account prosodic patterns and other visual signals, such as gaze. The empirical findings presented here provide a first glimpse of the role of the body in the psycholinguistic processes underpinning human communication.

  4. Do faster swimmers spend longer underwater than slower swimmers at World Championships? (United States)

    Veiga, Santiago; Roig, Andreu; Gómez-Ruano, Miguel A


    The main objectives of the present research were (1) to examine the relationships between the distances travelled underwater during the start and turn segments with swimming race performance at the elite level and (2) to determine if the individualised-distance start and turn parameters affect the overall race performance. The race parameters of the 100 and 200 m events during 2013 World Championships were measured by an innovative image-processing system (InThePool(®) 2.0). Overall, 100 m race times were largely related to faster start velocities in men's breaststroke and freestyle events. Conversely, overall, 200 m race times were largely related to longer starting distances in the women's butterfly events, to longer turn distances in men's and women's backstroke and women's butterfly events and to shorter turn distances in women's freestyle events. Changes on the start or turn velocities could represent moderate time improvements in most of the 100 m events, whereas modifications on the start or turn distances (especially in the last turn) could provide elite swimmers with time improvements of practical importance on the 200 m events. The evaluation of races by individualised-distance parameters should be provided to elite swimmers in order to decide the most appropriate race segment configuration for each event.

  5. Soft robotics: a review and progress towards faster and higher torque actuators (presentation video) (United States)

    Shepherd, Robert


    Last year, nearly 160,000 industrial robots were shipped worldwide—into a total market valued at 26 Bn (including hardware, software, and peripherals).[1] Service robots for professional (e.g., defense, medical, agriculture) and personal (e.g., household, handicap assistance, toys, and education) use accounted for 16,000 units, 3.4 Bn and 3,000,000 units, $1.2 Bn respectively.[1] The vast majority of these robotic systems use fully actuated, rigid components that take little advantage of passive dynamics. Soft robotics is a field that is taking advantage of compliant actuators and passive dynamics to achieve several goals: reduced design, manufacturing and control complexity, improved energy efficiency, more sophisticated motions, and safe human-machine interactions to name a few. The potential for societal impact is immense. In some instances, soft actuators have achieved commercial success; however, large scale adoption will require improved methods of controlling non-linear systems, greater reliability in their function, and increased utility from faster and more forceful actuation. In my talk, I will describe efforts from my work in the Whitesides group at Harvard to prove sophisticated motions in these machines using simple controls, as well capabilities unique to soft machines. I will also describe the potential for combinations of different classes of soft actuators (e.g., electrically and pneumatically actuated systems) to improve the utility of soft robots. 1. World Robotics - Industrial Robots 2013, 2013, International Federation of Robotics.

  6. Emotion, Etmnooi, or Emitoon?--Faster lexical access to emotional than to neutral words during reading. (United States)

    Kissler, Johanna; Herbert, Cornelia


    Cortical processing of emotional words differs from that of neutral words. Using EEG event-related potentials (ERPs), the present study examines the functional stage(s) of this differentiation. Positive, negative, and neutral nouns were randomly mixed with pseudowords and letter strings derived from words within each valence and presented for reading while participants' EEG was recorded. Results indicated emotion effects in the N1 (110-140 ms), early posterior negativity (EPN, 216-320) and late positive potential (LPP, 432-500 ms) time windows. Across valence, orthographic word-form effects occurred from about 180 ms after stimulus presentation. Crucially, in emotional words, lexicality effects (real words versus pseudowords) were identified from 216 ms, words being more negative over posterior cortex, coinciding with EPN effects, whereas neutral words differed from pseudowords only after 320 ms. Emotional content affects word processing at pre-lexical, lexical and post-lexical levels, but remarkably lexical access to emotional words is faster than access to neutral words. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Some improvements in the theory of faster-than-light particles

    International Nuclear Information System (INIS)

    Schwartz, C.


    The relationship between differentially conserved quantities (electric current density J/sup μ/, stress tensor density T/sup munu/, etc.) and the conserved integral quantities (charge Q, energy-momentum P/sup ν/, etc.) is carefully studied for the case of faster-than-light particles. It is found that there is no problem of ''negative-energy states'' and no need for the ''reinterpretation principle'' used by previous authors. The central lesson learned is that the concept of ''charge'' or ''momentum'' or ''energy'' even for a free particle should not be taken as separable from the concept of the particle moving ''in'' or ''out'' relative to some interaction. Mathematically it is just a matter of certain minus signs in otherwise familiar formulas, but it is essential to include these factors in order to get a relativistically consistent theory for tachyons. Basic application is made to the classical theory of point particles with electromagnetic interactions, the classical theory of a free field, and the quantum theory of a free field. The earlier tachyon quantum theory of Feinberg is drastically revised

  8. Faster, Hotter MHD-Driven Jets Using RF Pre-Ionization (United States)

    Chaplin, Vernon; Bellan, Paul


    We are studying MHD-driven jets relevant to spheromak formation and to astrophysical jets. Previous experiments at Caltech have focused on plasmas created by breaking down neutral gas using high voltage. The Paschen breakdown criterion governing this process sets an undesirable lower limit for the jet density. To overcome this constraint, we have designed and constructed a pre-ionization system powered by a pulsed 3 kW 13.56 MHz class D RF power amplifier. The RF amplifier is mounted on a compact printed circuit board and powered by AA batteries, allowing it to float at the high voltage of the center electrode of the jet experiment. The lower-density plasma jets created with the aid of RF pre-ionization are expected to be faster, hotter, and have higher Lundquist numbers than jets created by Paschen breakdown, opening up a new regime of study with increased relevance to astrophysics. The installation of the pre-ionization system on the MHD-driven jet experiment will be described, and details of the RF source operation and properties of the pre-ionized plasma will be summarized. Results from experiments with pre-ionized jets will be presented if available.

  9. Faster-Than-Real-Time Simulation of Lithium Ion Batteries with Full Spatial and Temporal Resolution

    Directory of Open Access Journals (Sweden)

    Sandip Mazumder


    Full Text Available A one-dimensional coupled electrochemical-thermal model of a lithium ion battery with full temporal and normal-to-electrode spatial resolution is presented. Only a single pair of electrodes is considered in the model. It is shown that simulation of a lithium ion battery with the inclusion of detailed transport phenomena and electrochemistry is possible with faster-than-real-time compute times. The governing conservation equations of mass, charge, and energy are discretized using the finite volume method and solved using an iterative procedure. The model is first successfully validated against experimental data for both charge and discharge processes in a LixC6-LiyMn2O4 battery. Finally, it is demonstrated for an arbitrary rapidly changing transient load typical of a hybrid electric vehicle drive cycle. The model is able to predict the cell voltage of a 15-minute drive cycle in less than 12 seconds of compute time on a laptop with a 2.33 GHz Intel Pentium 4 processor.

  10. Intervertebral disc detection in X-ray images using faster R-CNN. (United States)

    Ruhan Sa; Owens, William; Wiegand, Raymond; Studin, Mark; Capoferri, Donald; Barooha, Kenneth; Greaux, Alexander; Rattray, Robert; Hutton, Adam; Cintineo, John; Chaudhary, Vipin


    Automatic identification of specific osseous landmarks on the spinal radiograph can be used to automate calculations for correcting ligament instability and injury, which affect 75% of patients injured in motor vehicle accidents. In this work, we propose to use deep learning based object detection method as the first step towards identifying landmark points in lateral lumbar X-ray images. The significant breakthrough of deep learning technology has made it a prevailing choice for perception based applications, however, the lack of large annotated training dataset has brought challenges to utilizing the technology in medical image processing field. In this work, we propose to fine tune a deep network, Faster-RCNN, a state-of-the-art deep detection network in natural image domain, using small annotated clinical datasets. In the experiment we show that, by using only 81 lateral lumbar X-Ray training images, one can achieve much better performance compared to traditional sliding window detection method on hand crafted features. Furthermore, we fine-tuned the network using 974 training images and tested on 108 images, which achieved average precision of 0.905 with average computation time of 3 second per image, which greatly outperformed traditional methods in terms of accuracy and efficiency.

  11. World oil demand's shift toward faster growing and less price-responsive products and regions

    International Nuclear Information System (INIS)

    Dargay, Joyce M.; Gately, Dermot


    Using data for 1971-2008, we estimate the effects of changes in price and income on world oil demand, disaggregated by product - transport oil, fuel oil (residual and heating oil), and other oil - for six groups of countries. Most of the demand reductions since 1973-74 were due to fuel-switching away from fuel oil, especially in the OECD; in addition, the collapse of the Former Soviet Union (FSU) reduced their oil consumption substantially. Demand for transport and other oil was much less price-responsive, and has grown almost as rapidly as income, especially outside the OECD and FSU. World oil demand has shifted toward products and regions that are faster growing and less price-responsive. In contrast to projections to 2030 of declining per-capita demand for the world as a whole - by the U.S. Department of Energy (DOE), International Energy Agency (IEA) and OPEC - we project modest growth. Our projections for total world demand in 2030 are at least 20% higher than projections by those three institutions, using similar assumptions about income growth and oil prices, because we project rest-of-world growth that is consistent with historical patterns, in contrast to the dramatic slowdowns which they project. (author)

  12. The Formation of Concentric Eyewalls with Heat Sink in a Simple Tropical Cyclone Model

    Directory of Open Access Journals (Sweden)

    Jia-Yi Peng


    Full Text Available A linearized, two-layer axisymmetric model analogous to Schubert el al. (1980 is used to simulate the formation of concentric eyewalls in an ideal strong tropical cyclone. By imposing a heat sink near the center of a cyclone the induced perturbation wind, through thermodynamic adjustment to the heat sink, forms a double-peak structure when the disturbance is added to the basic state tangential wind. The heat sink represents, in a crude way, evaporative cooling of precipitation falling from cloud during late stage convective activity or a cooling through environmental advection. Detailed profiling of the induced double-peak wind structure is dependent on the radial profile of the imposed heat sink. After the double-peak tangential wind structure is formed, if a heat source corresponding to a new convective activity is generated inside the outer maximum tangential wind, the outer eyewall contracts and strengthens while the inner eyewall weakens. This result suggests that thermodynamic adjustments to changes in the heating of a tropical-cyclone-core region may contribute to the formation of the double-eyewall phenomenon.

  13. Spring feeding by pink-footed geese reduces carbon stocks and sink strength in tundra ecosystems

    NARCIS (Netherlands)

    Van der Wal, R.; Sjögersten, S.; Woodin, S.J.; Cooper, E.J.; Jónsdóttir, I.S.; Kuijper, D.; Fox, A.D.; Huiskes, A.H.L.


    Tundra ecosystems are widely recognized as precious areas and globally important carbon (C) sinks, yet our understanding of potential threats to these habitats and their large soil C store is limited. Land-use changes and conservation measures in temperate regions have led to a dramatic expansion of

  14. "JCE" Classroom Activity #108. Using Archimedes' Principle to Explain Floating and Sinking Cans (United States)

    Sanger, Michael J.


    In this activity, students (working alone or in groups) measure the mass of several soda cans (diet and regular soda) along with the mass of water that each can displaces. The students are then asked to compare these two mass values for the sinking cans and for the floating cans. The purpose of this activity is for students to determine that the…

  15. Hormonal and metabolic regulation of tomato fruit sink activity and yield under salinity

    DEFF Research Database (Denmark)

    Albacete, Alfonso; Cantero-Navarro, Elena; Balibrea, María E.


    in the root (up to 30%), owing to an increase in the fruit number (lower flower abortion) and in fruit weight. This is possibly related to a recovery of sink activity in reproductive tissues due to both (i) increase in sucrolytic activities (cwInv, sucrose synthase, and vacuolar and cytoplasmic invertases...

  16. Mangrove production and carbon sinks: A revision of global budget estimates (United States)

    Bouillon, S.; Borges, A.V.; Castaneda-Moya, E.; Diele, K.; Dittmar, T.; Duke, N.C.; Kristensen, E.; Lee, S.-Y.; Marchand, C.; Middelburg, J.J.; Rivera-Monroy, V. H.; Smith, T. J.; Twilley, R.R.


    Mangrove forests are highly productive but globally threatened coastal ecosystems, whose role in the carbon budget of the coastal zone has long been debated. Here we provide a comprehensive synthesis of the available data on carbon fluxes in mangrove ecosystems. A reassessment of global mangrove primary production from the literature results in a conservative estimate of ???-218 ?? 72 Tg C a-1. When using the best available estimates of various carbon sinks (organic carbon export, sediment burial, and mineralization), it appears that >50% of the carbon fixed by mangrove vegetation is unaccounted for. This unaccounted carbon sink is conservatively estimated at ??? 112 ?? 85 Tg C a-1, equivalent in magnitude to ??? 30-40% of the global riverine organic carbon input to the coastal zone. Our analysis suggests that mineralization is severely underestimated, and that the majority of carbon export from mangroves to adjacent waters occurs as dissolved inorganic carbon (DIC). CO2 efflux from sediments and creek waters and tidal export of DIC appear to be the major sinks. These processes are quantitatively comparable in magnitude to the unaccounted carbon sink in current budgets, but are not yet adequately constrained with the limited published data available so far. Copyright 2008 by the American Geophysical Union.

  17. Ultimate heat sink and directly associated heat transport systems for nuclear power plants

    International Nuclear Information System (INIS)


    The scope of the Guide covers design considerations for various types of ultimate heat sinks (UHS) and directly associated heat transport systems, and for types and sources of related heat transport fluids. The scope encompasses the conditions for using the UHS for reactor safety following postulated initiating events, as well as its selection, sizing and reliability

  18. Physiological constrains on Sverdrup's Critical-Depth-Hypothesis: the influences of dark respiration and sinking

    DEFF Research Database (Denmark)

    Lindemann, Christian; Backhaus, Jan O.; St. John, Michael


    conditions as driven by convective mixing, and the onset of thermal stratification resulting in the spring bloom. The comparison between a simulation using a standard fixed rate approach in line with the original Sverdrup hypothesis and a simulation parameterized to include variable respiration and sinking...

  19. Study on the sensitivity of the vertical cooling (heat sink) on the ...

    Indian Academy of Sciences (India)

    R.Narasimhan(krishtel emaging) 1461 1996 Oct 15 13:05:22

    excessive winter and spring snow cover over Eura- sia is that less solar energy is available to heat the atmosphere due to high albedo of snow. They modeled the anomalous cooling associated with the increased snow cover in Eurasia as a heat sink and prescribed the same to the north of the trop- ical heat sources.

  20. On integrability of a heavy rigid body sinking in an ideal fluid

    DEFF Research Database (Denmark)

    Deriabine, Mikhail; Hjorth, Poul G.


    We consider a rigid body possessing 3 mutually perpendicular planes of symmetry, sinking in an ideal fluid. We prove that the general solution to the equations of motion branches in the complex time plane, and that the equations consequently are not algebraically integrable. We show...

  1. Phosphate sink containing two-component signaling systems as tunable threshold devices

    DEFF Research Database (Denmark)

    Amin, Munia; Kothamachu, Varun B; Feliu, Elisenda


    rapid signal termination, whereby one of the RRs acts as a phosphate sink towards the other RR (i.e. the output RR), but also implements a sigmoidal signal-response relationship. We identify two mathematical conditions on system parameters that are necessary for sigmoidal signal-response relationships...

  2. Study of ultimate heat sink to Angra-1,2 and 3 Nuclear Power Plants

    International Nuclear Information System (INIS)

    Moreira, R.M.; Pinto, A.M.F.


    This report presents the premises, results and conclusion of study done to ultimate heat sink of Angra 1,2 and 3 units, with base in postulated accidents that generate transient heat discharges to environment. It's explicitily presumed the eventuality of discharging heat water recirculation. (C.M.) [pt

  3. Sinks and sources : a strategy to involve forest communities in Tanzania in global climate policy

    NARCIS (Netherlands)

    Zahabu, E.M.


    At present only the sink ability of forest to sequester atmospheric CO2 through establishing new forests is credited under the current UNFCCC climate change mitigation mechanisms in developing countries, i.e. the Clean Development Mechanism (CDM) of the Kyoto Protocol. Other forest practices such as

  4. Tropical nighttime warming as a dominant driver of variability in the terrestrial carbon sink (United States)

    William R. L. Anderegg; Ashley P. Ballantyne; W. Kolby Smith; Joseph Majkut; Sam Rabin; Claudie Beaulieu; Richard Birdsey; John P. Dunne; Richard A. Houghton; Ranga B. Myneni; Yude Pan; Jorge L. Sarmiento; Nathan Serota; Elena Shevliakova; Pieter Tans; Stephen W. Pacala


    The terrestrial biosphere is currently a strong carbon (C) sink but may switch to a source in the 21st century as climate-driven losses exceed CO2-driven C gains, thereby accelerating global warming. Although it has long been recognized that tropical climate plays a critical role in regulating interannual climate variability, the causal link...

  5. Estimation of in-canopy ammonia sources and sinks in a fertilized Zea mays field (United States)

    An analytical model was developed that describes the in-canopy vertical distribution of NH3 source and sinks and vertical fluxes in a fertilized agricultural setting using measured in-canopy concentration and wind speed profiles. This model was applied to quantify in-canopy air-s...

  6. Modeling the reversible sink effect in response to transient contaminant sources

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dongye; Little, John C.; Hodgson, Alfred T.


    A physically based diffusion model is used to evaluate the sink effect of diffusion-controlled indoor materials and to predict the transient contaminant concentration in indoor air in response to several time-varying contaminant sources. For simplicity, it is assumed the predominant indoor material is a homogeneous slab, initially free of contaminant, and the air within the room is well mixed. The model enables transient volatile organic compound (VOC) concentrations to be predicted based on the material/air partition coefficient (K) and the material-phase diffusion coefficient (D) of the sink. Model predictions are made for three scenarios, each mimicking a realistic situation in a building. Styrene, phenol, and naphthalene are used as representative VOCs. A styrene butadiene rubber (SBR) backed carpet, vinyl flooring (VF), and a polyurethane foam (PUF) carpet cushion are considered as typical indoor sinks. In scenarios involving a sinusoidal VOC input and a double exponential decaying input, the model predicts the sink has a modest impact for SBR/styrene, but the effect increases for VF/phenol and PUF/naphthalene. In contrast, for an episodic chemical spill, SBR is predicted to reduce the peak styrene concentration considerably. A parametric study reveals for systems involving a large equilibrium constant (K), the kinetic constant (D) will govern the shape of the resulting gas-phase concentration profile. On the other hand, for systems with a relaxed mass transfer resistance, K will dominate the profile.

  7. Lidar-derived estimate and uncertainty of carbon sink in successional phases of woody encroachment (United States)

    Woody encroachment is a globally occurring phenomenon that is thought to contribute significantly to the global carbon (C) sink. The C contribution needs to be estimated at regional and local scales to address large uncertainties present in the global- and continental-scale estimates and guide regio...

  8. Increased sink strength offsets the inhibitory effect of sucrose on sugarcane photosynthesis. (United States)

    Ribeiro, Rafael V; Machado, Eduardo C; Magalhães Filho, José R; Lobo, Ana Karla M; Martins, Márcio O; Silveira, Joaquim A G; Yin, Xinyou; Struik, Paul C


    Spraying sucrose inhibits photosynthesis by impairing Rubisco activity and stomatal conductance (g s ), whereas increasing sink demand by partially darkening the plant stimulates sugarcane photosynthesis. We hypothesized that the stimulatory effect of darkness can offset the inhibitory effect of exogenous sucrose on photosynthesis. Source-sink relationship was perturbed in two sugarcane cultivars by imposing partial darkness, spraying a sucrose solution (50mM) and their combination. Five days after the onset of the treatments, the maximum Rubisco carboxylation rate (V cmax ) and the initial slope of A-C i curve (k) were estimated by measuring leaf gas exchange and chlorophyll fluorescence. Photosynthesis was inhibited by sucrose spraying in both genotypes, through decreases in V cmax , k, g s and ATP production driven by electron transport (J atp ). Photosynthesis of plants subjected to the combination of partial darkness and sucrose spraying was similar to photosynthesis of reference plants for both genotypes. Significant increases in V cmax , g s and J atp and marginal increases in k were noticed when combining partial darkness and sucrose spraying compared with sucrose spraying alone. Our data also revealed that increases in sink strength due to partial darkness offset the inhibition of sugarcane photosynthesis caused by sucrose spraying, enhancing the knowledge on endogenous regulation of sugarcane photosynthesis through the source-sink relationship. Copyright © 2016 Elsevier GmbH. All rights reserved.

  9. Increased sink strength offsets the inhibitory effect of sucrose on sugarcane photosynthesis

    NARCIS (Netherlands)

    Ribeiro, Rafael V.; Machado, Eduardo C.; Magalhães Filho, José R.; Lobo, Ana K.M.; Martins, Márcio O.; Silveira, Joaquim A.G.; Yin, Xinyou; Struik, Paul C.


    Spraying sucrose inhibits photosynthesis by impairing Rubisco activity and stomatal conductance (gs), whereas increasing sink demand by partially darkening the plant stimulates sugarcane photosynthesis. We hypothesized that the stimulatory effect of darkness can offset the inhibitory

  10. Inverse modeling of methane sources and sinks using the adjoint of a global transport model

    NARCIS (Netherlands)

    Houweling, S; Kaminski, T; Dentener, F; Lelieveld, J; Heimann, M


    An inverse modeling method is presented to evaluate the sources and sinks of atmospheric methane. An adjoint version of a global transport model has been used to estimate these fluxes at a relatively high spatial and temporal resolution. Measurements from 34 monitoring stations and 11 locations

  11. Is the Southern Benguela a significant regional sink of CO2?

    CSIR Research Space (South Africa)

    Gregor, L


    Full Text Available boundary upwelling systems in the global ocean, the southern Benguela was found to be a very small net annual CO(sub2) sink of -1.4 ± 0.6 mol C/m(sup2) per year (1.7 Mt C/year). Regional primary productivity was offset by nearly equal rates of sediment...

  12. Effect of altered sink:source ratio on photosynthetic metabolism of source leaves

    International Nuclear Information System (INIS)

    Plaut, Z.; Mayoral, M.L.; Reinhold, L.


    When seven crop species were grown under identical environmental conditions, decreased sink:source ratio led to a decreased photosynthetic rate within 1 to 3 days in Cucumis sativus L., Gossypium hirsutum L., and Raphanus sativus L., but not in Capsicum annuum L., Solanum melongena L., Phaseolus vulgaris L., or Ricinus communis L. The decrease was not associated with stomatal closure. In cotton and cucumbers, sink removal led to an increase in starch and sugar content, in glucose 6-phosphate and fructose 6-phosphate pools, and in the proportion of 14 C detected in sugar phosphates and UDPglucose following 14 CO 2 supply. When mannose was supplied to leaf discs to sequester cytoplasmic inorganic phosphate, promotion of starch synthesis, and inhibition of CO 2 fixation, were observed in control discs, but not in discs from treated plants. Phosphate buffer reduced starch synthesis in the latter, but not the former discs. The findings suggest that sink removal led to a decreased ratio inorganic phosphate:phosphorylated compounds. In beans 14 C in sugar phosphates increased following sink removal, but without sucrose accumulation, suggesting tighter feedback control of sugar level. Starch accumulated to higher levels than in the other plants, but CO 2 fixation rate was constant for several days

  13. Thermal effect of a thermoelectric generator on parallel microchannel heat sink

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Rosendahl, Lasse


    Thermoelectric generators (TEG) convert heat energy to electrical power by means of semiconductor charge carriers serving as working fluid. In this work, a TEG is applied to a parallel microchannel heat sink. The effect of the inlet plenum arrangement on the laminar flow distribution in the chann...

  14. How costly are carbon offsets? A meta-analysis of carbon forest sinks

    NARCIS (Netherlands)

    Kooten, van G.C.; Eagle, A.J.; Manley, J.; Smolak, T.


    Carbon terrestrial sinks are seen as a low-cost alternative to fuel switching and reduced fossil fuel use for lowering atmospheric CO2. As a result of agreements reached at Bonn and Marrakech, carbon offsets have taken on much greater importance in meeting Kyoto targets for the first commitment

  15. How costly are carbon offsets : a meta-analysis of forest carbon sinks

    International Nuclear Information System (INIS)

    Van Kooten, G.C.; Eagle, A.J.; Manley, J.; Smolak, T.M.


    Carbon terrestrial sinks are one of the many proposed mitigation responses to climate change. Carbon sinks are considered to be a low-cost alternative to fuel switching and reduced fossil fuel consumption for reducing atmospheric carbon dioxide emissions. This study examined the costs of sequestering carbon in terrestrial ecosystems via forestry activities. A meta-regression analysis was used to determine which factors influence the costs of carbon sequestration via forest activities. Important concerns about how the Kyoto Protocol may be implemented were also addressed. The meta-regression analysis was used to examine 981 estimates from 55 studies on the cost of creating carbon offsets using forestry. Baseline cost estimates are US$46.62 to 260.29 per tC. Tree planting and agroforestry increases costs by more than 200 per cent. Costs are lowest when post-harvest storage of carbon in wood products is considered, or when biomass is substituted for fossil fuels in energy production. The meta-analysis also considered land use, land-use change and forestry (LULUCF) policies that increase the carbon sink functions of terrestrial ecosystems. The main motive for using sinks in the accounting process is that they avoid the use of expensive controls for the emission of carbon dioxide and other greenhouse gases. refs., tabs

  16. Copper matrix composites as heat sink materials for water-cooled divertor target

    Directory of Open Access Journals (Sweden)

    Jeong-Ha You


    Full Text Available According to the recent high heat flux (HHF qualification tests of ITER divertor target mock-ups and the preliminary design studies of DEMO divertor target, the performance of CuCrZr alloy, the baseline heat sink material for DEMO divertor, seems to only marginally cover the envisaged operation regime. The structural integrity of the CuCrZr heat sink was shown to be affected by plastic fatigue at 20 MW/m². The relatively high neutron irradiation dose expected for the DEMO divertor target is another serious concern, as it would cause significant embrittlement below 250 °C or irradiation creep above 350 °C. Hence, an advanced design concept of the divertor target needs to be devised for DEMO in order to enhance the HHF performance so that the structural design criteria are fulfilled for full operation scenarios including slow transients. The biggest potential lies in copper-matrix composite materials for the heat sink. In this article, three promising Cu-matrix composite materials are reviewed in terms of thermal, mechanical and HHF performance as structural heat sink materials. The considered candidates are W particle-reinforced, W wire-reinforced and SiC fiber-reinforced Cu matrix composites. The comprehensive results of recent studies on fabrication technology, design concepts, materials properties and the HHF performance of mock-ups are presented. Limitations and challenges are discussed.

  17. Values for rooted-tree and sink-tree digraphs games and sharing a river

    NARCIS (Netherlands)

    Khmelnitskaya, Anna Borisovna


    We introduce values for rooted-tree and sink-tree digraph games axiomatically and provide their explicit formula representation. These values may be considered as natural extensions of the lower equivalent and upper equivalent solutions for line-graph games studied in van den Brink et al. (Econ

  18. Efficient Data Collection by Mobile Sink to Detect Phenomena in Internet of Things

    Directory of Open Access Journals (Sweden)

    Amany Abu Safia


    Full Text Available With the rapid development of Internet of Things (IoT, more and more static and mobile sensors are being deployed for sensing and tracking environmental phenomena, such as fire, oil spills and air pollution. As these sensors are usually battery-powered, energy-efficient algorithms are required to extend the sensors’ lifetime. Moreover, forwarding sensed data towards a static sink causes quick battery depletion of the sinks’ nearby sensors. Therefore, in this paper, we propose a distributed energy-efficient algorithm, called the Hilbert-order Collection Strategy (HCS, which uses a mobile sink (e.g., drone to collect data from a mobile wireless sensor network (mWSN and detect environmental phenomena. The mWSN consists of mobile sensors that sense environmental data. These mobile sensors self-organize themselves into groups. The sensors of each group elect a group head (GH, which collects data from the mobile sensors in its group. Periodically, a mobile sink passes by the locations of the GHs (data collection path to collect their data. The collected data are aggregated to discover a global phenomenon. To shorten the data collection path, which results in reducing the energy cost, the mobile sink establishes the path based on the order of Hilbert values of the GHs’ locations. Furthermore, the paper proposes two optimization techniques for data collection to further reduce the energy cost of mWSN and reduce the data loss.

  19. Data Transmission Scheme Using Mobile Sink in Static Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Awais Ahmad


    Full Text Available Multihop communication in wireless sensor network (WSN brings new challenges in reliable data transmission. Recent work shows that data collection from sensor nodes using mobile sink minimizes multihop data transmission and improves energy efficiency. However, due to continuous movements, mobile sink has limited communication time to collect data from sensor nodes, which results in rapid depletion of node’s energy. Therefore, we propose a data transmission scheme that addresses the aforementioned constraints. The proposed scheme first finds out the group based region on the basis of localization information of the sensor nodes and predefined trajectory information of a mobile sink. After determining the group region in the network, selection of master nodes is made. The master nodes directly transmit their data to the mobile sink upon its arrival at their group region through restricted flooding scheme. In addition, the agent node concept is introduced for swapping of the role of the master nodes in each group region. The master node when consuming energy up to a certain threshold, neighboring node with second highest residual energy is selected as an agent node. The mathematical analysis shows that the selection of agent node maximizes the throughput while minimizing transmission delay in the network.

  20. Coexistence in streams: Do source-sink dynamics allow salamanders to persist with fish predators? (United States)

    Sepulveda, A.J.; Lowe, W.H.


    Theory suggests that source-sink dynamics can allow coexistence of intraguild predators and prey, but empirical evidence for this coexistence mechanism is limited. We used capture-mark-recapture, genetic methods, and stable isotopes to test whether source-sink dynamics promote coexistence between stream fishes, the intraguild predator, and stream salamanders (Dicamptodon aterrimus), the intraguild prey. Salamander populations from upstream reaches without fish were predicted to maintain or supplement sink populations in downstream reaches with fish. We found instead that downstream reaches with fish were not sinks even though fish consumed salamander larvae-apparent survival, recruitment, and population growth rate did not differ between upstream and downstream reaches. There was also no difference between upstream and downstream reaches in net emigration. We did find that D. aterrimus moved frequently along streams, but believe that this is a response to seasonal habitat changes rather than intraguild predation. Our study provides empirical evidence that local-scale mechanisms are more important than dispersal dynamics to coexistence of streams salamanders and fish. More broadly, it shows the value of empirical data on dispersal and gene flow for distinguishing between local and spatial mechanisms of coexistence. ?? 2011 Springer-Verlag.

  1. Outbreak of Burkholderia cepacia complex among ventilated pediatric patients linked to hospital sinks. (United States)

    Lucero, Cynthia A; Cohen, Adam L; Trevino, Ingrid; Rupp, Angela Hammer; Harris, Michelle; Forkan-Kelly, Sinead; Noble-Wang, Judith; Jensen, Bette; Shams, Alicia; Arduino, Matthew J; LiPuma, John J; Gerber, Susan I; Srinivasan, Arjun


    We investigated a cluster of Burkholderia cepacia complex colonization in ventilated pediatric patients. Isolates from 15 patients, 2 sink drains, and several ventilator components were found to belong to a single B cenocepacia clone. Hospital tap water used during oral and tracheostomy care was identified as the most likely mechanism for transmission. Published by Mosby, Inc.

  2. Effect of type and concentration of ballasting particles on sinking rate of marine snow produced by the Appendicularian Oikopleura dioica

    DEFF Research Database (Denmark)

    Lombard, Fabien; Guidi, L.; Kiørboe, Thomas


    Ballast material (organic, opal, calcite, lithogenic) is suggested to affect sinking speed of aggregates in the ocean. Here, we tested this hypothesis by incubating appendicularians in suspensions of different algae or Saharan dust, and observing the sinking speed of the marine snow formed by the...

  3. Enhancement of heat dissipation of LED module with cupric-oxide composite coating on aluminum-alloy heat sink

    International Nuclear Information System (INIS)

    Kim, Donghyun; Lee, Junghoon; Kim, Junho; Choi, Chang-Hwan; Chung, Wonsub


    Highlights: • We fabricate the CuO/resin composite coating layer on aluminum alloy heat sink. • CuO/resin coating considerably improved the surface emissivity. • The LED junction temperature was reduced by CuO/resin coated heat sink. • The thermal resistance of heat sink was decreased by CuO/resin composite coating at 200 μm thickness. - Abstract: A composite coating composed of cupric oxide (CuO) and silicon-based resin was applied to an aluminum-alloy heat sink for a light emitting diode (LED) module. The purpose of the composite coating is to improve the heat dissipation performance of heat sink by enhancing thermal radiation emission. The heat dissipation performance was investigated in terms of LED junction temperature and thermal resistance using a thermal transient method. The CuO and silicon-based resin composite coating showed higher emissivity, and the lower junction temperature and thermal resistance of the heat sink was achieved. In addition, a continuous operation test of the LED chip with the heat sink revealed that the surface treated with the CuO composite coating stably dissipated heat without degradation. In conclusion, the composite coating proposed here showed a significant improvement of the heat dissipation performance of the aluminum-alloy heat sink due to the enhanced thermal radiation property.

  4. Evaluation of railway capacity

    DEFF Research Database (Denmark)

    Landex, Alex; Kaas, Anders H.; Schittenhelm, Bernd


    capacity consumptions. This paper describes the UIC 406 method and how it is expounded in Denmark. The paper describes the importance of choosing the right length of the line sections examined and how line sections with multiple track sections are examined. Furthermore, the possibility of using idle...

  5. Building capacity in Benin

    International Development Research Centre (IDRC) Digital Library (Canada)

    sigp1. Building capacity in. Benin. Training of technical staff of municipalities in the Okpara Basin of Benin in the use of GIS tools for water management, hydrological .... Practical exercises allowed participants to define the catchment area of the ...

  6. Vibration attenuation of a continuous rotor-blisk-journal bearing system employing smooth nonlinear energy sinks (United States)

    Bab, Saeed; Khadem, S. E.; Shahgholi, Majid; Abbasi, Amirhassan


    The current paper investigates the effects of a number of smooth nonlinear energy sinks (NESs) located on the disk and bearings on the vibration attenuation of a rotor-blisk-journal bearing system under excitation of a mass eccentricity force. The blade and rotor are modeled using the Euler-Bernoulli beam theory. The nonlinear energy sinks on the bearing have a linear damping and an essentially nonlinear stiffness. The nonlinear energy sinks on the disk have a linear damping, linear stiffness, and an essentially nonlinear stiffness. It can be seen that the linear stiffness of the NESs on the disk is eliminated by the negative stiffness induced by the centrifugal force, and the collection of the NESs can be tuned to a required rotational speed of the rotor by varying the linear stiffness of the NESs. Furthermore, the remained stiffness of the NESs on the disk after elimination of their linear stiffness, would be essentially a nonlinear (nonlinearizable) one. Two nonlinear energy sinks in the vertical axes are positioned on the bearing housing and nnd NESs are located on the perimeter of the disk. The equations of motion are extracted using the extended Hamilton principle. The modal coordinates and complex transformations are employed to decrease the number of equations of motion. A genetic algorithm is used to optimize the parameters of the nonlinear energy sinks and its objective function is considered as minimizing the vibration of the rotating system within an operating speed range. In order to examine the periodic and non-periodic solutions of the system, time history, bifurcation diagram, Poincaré map, phase portrait, Lyapunov exponent, and power spectra analyses are performed. System shows periodic and quasi-periodic motions for different values of the system parameters. It is shown that the NESs on the disk and bearings have almost local effects on vibration reduction of rotating system. In addition, the optimum NESs remove the instability region from the

  7. Energy Efficient Sensor Scheduling with a Mobile Sink Node for the Target Tracking Application

    Directory of Open Access Journals (Sweden)

    Malin Premaratne


    Full Text Available Measurement losses adversely affect the performance of target tracking. The sensor network’s life span depends on how efficiently the sensor nodes consume energy. In this paper, we focus on minimizing the total energy consumed by the sensor nodes whilst avoiding measurement losses. Since transmitting data over a long distance consumes a significant amount of energy, a mobile sink node collects the measurements and transmits them to the base station. We assume that the default transmission range of the activated sensor node is limited and it can be increased to maximum range only if the mobile sink node is out-side the default transmission range. Moreover, the active sensor node can be changed after a certain time period. The problem is to select an optimal sensor sequence which minimizes the total energy consumed by the sensor nodes. In this paper, we consider two different problems depend on the mobile sink node’s path. First, we assume that the mobile sink node’s position is known for the entire time horizon and use the dynamic programming technique to solve the problem. Second, the position of the sink node is varied over time according to a known Markov chain, and the problem is solved by stochastic dynamic programming. We also present sub-optimal methods to solve our problem. A numerical example is presented in order to discuss the proposed methods’ performance.

  8. Sinks in the landscape, Boltzmann brains and the cosmological constant problem (United States)

    Linde, Andrei


    This paper extends a recent investigation of the string theory landscape (Ceresole et al 2006 Phys. Rev. D 74 086010), where it was found that the decay rate of de Sitter (dS) vacua to a collapsing space with a negative vacuum energy can be quite large. The parts of space that experience a decay to a collapsing space, or to a Minkowski vacuum, never return back to dS space. The channels of irreversible vacuum decay serve as sinks for the probability flow. The existence of such sinks is a distinguishing feature of the string theory landscape. We describe relations between several different probability measures for eternal inflation taking into account the existence of the sinks. The local (comoving) description of the inflationary multiverse suffers from the so-called Boltzmann brain (BB) problem unless the probability of the decay to the sinks is sufficiently large. We show that some versions of the global (volume-weighted) description do not have this problem even if one ignores the existence of the sinks. We argue that if the number of different vacua in the landscape is large enough, the anthropic solution of the cosmological constant problem in the string landscape scenario should be valid for a broad class of the probability measures which solve the BB problem. If this is correct, the solution of the cosmological constant problem may be essentially measure-independent. Finally, we describe a simplified approach to the calculations of anthropic probabilities in the landscape, which is less ambitious but also less ambiguous than other methods. To the memory of Eugene Feinberg, who was trying to make a bridge between science, philosophy and art.

  9. Sources and sinks of selected trace gases in the tropospheric boundary layer of the eastern United States (United States)

    White, Marguerite L.

    capacity were the major factors influencing COS uptake rates. The loblolly pines exhibited substantial COS consumption overnight (50% of daytime rates) that was independent of CO2 assimilation. This suggests current estimates of the global vegetative COS sink, which assume that COS and CO2 are consumed simultaneously, may need to be reevaluated.

  10. Modelling of the damaged zone induced by the shaft sinking of the Meuse/Haute-Marne underground laboratory (East argilites)

    International Nuclear Information System (INIS)

    Miehe, Baptiste


    From a geomechanical point of view, the safety of an underground storage for the radioactive waste requires to characterize the damaged zone induced by the shaft sinking for the storage cavities. Then, the objective of this thesis is to simulate the hydro-mechanical response of the East argilites to the shaft sinking for the Meuse/Haute-Marne underground laboratory, in order to compare the results to the in situ measurements which will be recorded in 2005 (REP experiment). Firstly we have analysed all the mechanical tests which had been carried out from 1995 to 2001. We have observed that each series has his own coherence, in terms of elastic parameters, mechanical strength or creep capacity. But there are some strong differences between the series. These differences, which are due to the experimental protocols and not to the material itself, have shown three important results: the re-saturation phases imposed by several laboratories have deteriorated the mechanical properties of the East argilites, the existence of an effective stress is not evident for these argilites, and their mechanical strength increases when they are dried. From these tests, we have distinguished three mechanisms that produce irreversible strains: compaction, pre-failure, failure. We have described each of them by a straightforward elasto-plastic model, based on the Mohr-Coulomb or Drucker-Prager criterion, with a linear softening. Thus we obtain a complete rheological model for the East argilites by considering simultaneously the three mechanisms (multi-criterion plasticity). Lastly, from the modelling we carried out, we can conclude that: to take into account the irreversible strains that occur before the failure has a great influence on the seize of the failure zone around the shaft (it is very small with respect to the case where the behaviour is elastic until the failure); the pore pressure diffusion modifies very little the mechanical response of the massif (the plastic strains created

  11. Slower Perception Followed by Faster Lexical Decision in Longer Words: A Diffusion Model Analysis. (United States)

    Oganian, Yulia; Froehlich, Eva; Schlickeiser, Ulrike; Hofmann, Markus J; Heekeren, Hauke R; Jacobs, Arthur M


    Effects of stimulus length on reaction times (RTs) in the lexical decision task are the topic of extensive research. While slower RTs are consistently found for longer pseudo-words, a finding coined the word length effect (WLE), some studies found no effects for words, and yet others reported faster RTs for longer words. Moreover, the WLE depends on the orthographic transparency of a language, with larger effects in more transparent orthographies. Here we investigate processes underlying the WLE in lexical decision in German-English bilinguals using a diffusion model (DM) analysis, which we compared to a linear regression approach. In the DM analysis, RT-accuracy distributions are characterized using parameters that reflect latent sub-processes, in particular evidence accumulation and decision-independent perceptual encoding, instead of typical parameters such as mean RT and accuracy. The regression approach showed a decrease in RTs with length for pseudo-words, but no length effect for words. However, DM analysis revealed that the null effect for words resulted from opposing effects of length on perceptual encoding and rate of evidence accumulation. Perceptual encoding times increased with length for words and pseudo-words, whereas the rate of evidence accumulation increased with length for real words but decreased for pseudo-words. A comparison between DM parameters in German and English suggested that orthographic transparency affects perceptual encoding, whereas effects of length on evidence accumulation are likely to reflect contextual information and the increase in available perceptual evidence with length. These opposing effects may account for the inconsistent findings on WLEs.

  12. Faster but Less Careful Prehension in Presence of High, Rather than Low, Social Status Attendees.

    Directory of Open Access Journals (Sweden)

    Carlo Fantoni

    Full Text Available Ample evidence attests that social intention, elicited through gestures explicitly signaling a request of communicative intention, affects the patterning of hand movement kinematics. The current study goes beyond the effect of social intention and addresses whether the same action of reaching to grasp an object for placing it in an end target position within or without a monitoring attendee's peripersonal space, can be moulded by pure social factors in general, and by social facilitation in particular. A motion tracking system (Optotrak Certus was used to record motor acts. We carefully avoided the usage of communicative intention by keeping constant both the visual information and the positional uncertainty of the end target position, while we systematically varied the social status of the attendee (a high, or a low social status in separated blocks. Only thirty acts performed in the presence of a different social status attendee, revealed a significant change of kinematic parameterization of hand movement, independently of the attendee's distance. The amplitude of peak velocity reached by the hand during the reach-to-grasp and the lift-to-place phase of the movement was larger in the high rather than in the low social status condition. By contrast, the deceleration time of the reach-to-grasp phase and the maximum grasp aperture was smaller in the high rather than in the low social status condition. These results indicated that the hand movement was faster but less carefully shaped in presence of a high, but not of a low social status attendee. This kinematic patterning suggests that being monitored by a high rather than a low social status attendee might lead participants to experience evaluation apprehension that informs the control of motor execution. Motor execution would rely more on feedforward motor control in the presence of a high social status human attendee, vs. feedback motor control, in the presence of a low social status attendee.

  13. Composition and Realization of Source-to-Sink High-Performance Flows: File Systems, Storage, Hosts, LAN and WAN

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chase Qishi [Univ. of Tennessee, Memphis, TN (United States)


    A number of Department of Energy (DOE) science applications, involving exascale computing systems and large experimental facilities, are expected to generate large volumes of data, in the range of petabytes to exabytes, which will be transported over wide-area networks for the purpose of storage, visualization, and analysis. To support such capabilities, significant progress has been made in various components including the deployment of 100 Gbps networks with future 1 Tbps bandwidth, increases in end-host capabilities with multiple cores and buses, capacity improvements in large disk arrays, and deployment of parallel file systems such as Lustre and GPFS. High-performance source-to-sink data flows must be composed of these component systems, which requires significant optimizations of the storage-to-host data and execution paths to match the edge and long-haul network connections. In particular, end systems are currently supported by 10-40 Gbps Network Interface Cards (NIC) and 8-32 Gbps storage Host Channel Adapters (HCAs), which carry the individual flows that collectively must reach network speeds of 100 Gbps and higher. Indeed, such data flows must be synthesized using multicore, multibus hosts connected to high-performance storage systems on one side and to the network on the other side. Current experimental results show that the constituent flows must be optimally composed and preserved from storage systems, across the hosts and the networks with minimal interference. Furthermore, such a capability must be made available transparently to the science users without placing undue demands on them to account for the details of underlying systems and networks. And, this task is expected to become even more complex in the future due to the increasing sophistication of hosts, storage systems, and networks that constitute the high-performance flows. The objectives of this proposal are to (1) develop and test the component technologies and their synthesis methods to

  14. Seismic capacity of switchgear

    International Nuclear Information System (INIS)

    Bandyopadhyay, K.; Hofmayer, C.; Kassir, M.; Pepper, S.


    As part of a component fragility program sponsored by the USNRC, BNL has collected existing information on the seismic capacity of switchgear assemblies from major manufacturers. Existing seismic test data for both low and medium voltage switchgear assemblies have been evaluated and the generic results are presented in this paper. The failure modes are identified and the corresponding generic lower bound capacity levels are established. The test response spectra have been used as a measure of the test vibration input. The results indicate that relays chatter at a very low input level at the base of the switchgear cabinet. This change of state of devices including relays have been observed. Breaker tripping occurs at a higher vibration level. Although the structural failure of internal elements have been noticed, the overall switchgear cabinet structure withstands a high vibration level. 5 refs., 2 figs., 2 tabs

  15. Absorptive Capacity and Diversity

    DEFF Research Database (Denmark)

    Kristinsson, Kári

    international business, organizational economics, strategic management, technology management and last but not least neo-Schumpeterian economics. The goal of this dissertation is to examine what many consider as neglected arguments from the work by Cohen and Levinthal and thereby illuminate an otherwise......One of the most influential contributions to neo-Schumpeterian economics is Cohen and Levinthal‘s papers on absorptive capacity. Since their publication in the late 1980s and early 1990s the concept absorptive capacity has had substantial impact on research in economics and management, including...... overlooked area of research. Although research based on Cohen and Levinthal‘s work has made considerable impact, there is scarcity of research on certain fundamental points argued by Cohen and Levinthal. Among these is the importance of employee diversity as well as the type and nature of interaction between...

  16. Photosynthetic capacity of senescent leaves for a subtropical broadleaf deciduous tree species Liquidambar formosana Hance. (United States)

    Luo, Zidong; Guan, Huade; Zhang, Xinping; Liu, Na


    Photosynthetic capacity and leaf life span generally determine how much carbon a plant assimilates during the growing season. Leaves of deciduous tree species start senescence in late season, but whether the senescent leaves still retain capacity of carbon assimilation remains a question. In this study, we investigated leaf phenology and photosynthesis of a subtropical broadleaf deciduous tree species Liquidambar formosana Hance in the central southern continental China. The results show that L. formosana has extended leaf senescence (more than 2 months) with a substantial number of red leaves persisting on the tree. Leaf photosynthetic capacity decreases over season, but the senescent red leaves still maintain relatively high photosynthetic capacity at 42%, 66% and 66% of the mature leaves for net photosynthesis rate, apparent quantum yield, and quantum yield at the light compensation point, respectively. These results indicate that L. formosana may still contribute to carbon sink during leaf senescence.

  17. Heat Capacity Mapping Mission (United States)

    Nilsson, C. S.; Andrews, J. C.; Scully-Power, P.; Ball, S.; Speechley, G.; Latham, A. R. (Principal Investigator)


    The Tasman Front was delineated by airborne expendable bathythermograph survey; and an Heat Capacity Mapping Mission (HCMM) IR image on the same day shows the same principal features as determined from ground-truth. It is clear that digital enhancement of HCMM images is necessary to map ocean surface temperatures and when done, the Tasman Front and other oceanographic features can be mapped by this method, even through considerable scattered cloud cover.

  18. CSTI High Capacity Power

    International Nuclear Information System (INIS)

    Winter, J.M.


    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY-86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase 1 of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY-88, the Advanced Technology Program was incorporated into NASA's new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed

  19. Geospatial Analysis of Atmospheric Haze Effect by Source and Sink Landscape (United States)

    Yu, T.; Xu, K.; Yuan, Z.


    Based on geospatial analysis model, this paper analyzes the relationship between the landscape patterns of source and sink in urban areas and atmospheric haze pollution. Firstly, the classification result and aerosol optical thickness (AOD) of Wuhan are divided into a number of square grids with the side length of 6 km, and the category level landscape indices (PLAND, PD, COHESION, LPI, FRAC_MN) and AOD of each grid are calculated. Then the source and sink landscapes of atmospheric haze pollution are selected based on the analysis of the correlation between landscape indices and AOD. Next, to make the following analysis more efficient, the indices selected before should be determined through the correlation coefficient between them. Finally, due to the spatial dependency and spatial heterogeneity of the data used in this paper, spatial autoregressive model and geo-weighted regression model are used to analyze atmospheric haze effect by source and sink landscape from the global and local level. The results show that the source landscape of atmospheric haze pollution is the building, and the sink landscapes are shrub and woodland. PLAND, PD and COHESION are suitable for describing the atmospheric haze effect by source and sink landscape. Comparing these models, the fitting effect of SLM, SEM and GWR is significantly better than that of OLS model. The SLM model is superior to the SEM model in this paper. Although the fitting effect of GWR model is more unsuited than that of SLM, the influence degree of influencing factors on atmospheric haze of different geography can be expressed clearer. Through the analysis results of these models, following conclusions can be summarized: Reducing the proportion of source landscape area and increasing the degree of fragmentation could cut down aerosol optical thickness; And distributing the source and sink landscape evenly and interspersedly could effectively reduce aerosol optical thickness which represents atmospheric haze

  20. Estimating Sources and Sinks of Methane from Soils in the Contiguous United States (CONUS) (United States)

    Shu, S.; Jain, A. K.; Kheshgi, H. S.


    The global methane (CH4) budget estimated based on state-of-the-art models remains highly uncertain. Sources and sinks of CH4 from soils, including wetlands, are the most important source of uncertainty. Soils are estimated to account for about 45% of global CH4 emissions. At the same time oxidation of CH4 by soils is a significant sink, representing about 10% of the total sink. However, most regional and global scale modeling studies of soil CH4 fluxes have ignored the sink through soil oxidation and the source of CH4 emissions from the wet soils with shallow water tables. In this study, we link a bottom-up soil gas diffusion and CH4 biogeochemistry model to a land surface model, ISAM, to calculate the sources, emissions from both wetlands and non-wetlands, and sinks, soil oxidation, of CH4 from soils for the CONUS over the period 1900-2100. The newly developed soil CH4 model framework consists of a gas diffusion module with the vertically resolved soil hydrology (depth up to 3.5 m soil) and soil organic carbon (SOC) and CH4 biogeochemistry module. SOC profile is estimated by modeling vertical soil mixing and thus can represent the deep SOC content and estimate CH4 production from the deep non-wetland soil. For the diffusion calculations, we separately consider both the dissolved and gaseous O2 and CH4 at each soil layer. For CH4 biogeochemistry, we parameterize the production, soil oxidation, ebullition and aerenchyma transportation of CH4 for both seasonal/permanent wetland and wet soil. The SWAMP inundated fraction dataset with 8-day temporal resolution is incorporated to prescribe the extent of permanent and seasonal wetland extent for the recent decade. The model is first evaluated using a compilation of published CH4 site measurement data for CONUS. We then perform two different model experiments: 1) forced by the CRUNCEP climate data from 1900 to 2010 to estimate the contemporary CH4 emission and 2) forced by a climate projection of IPCC's highest

  1. Rapid and Deep Proteomes by Faster Sequencing on a Benchtop Quadrupole Ultra-High-Field Orbitrap Mass Spectrometer

    DEFF Research Database (Denmark)

    Kelstrup, Christian D; Jersie-Christensen, Rosa R; Batth, Tanveer Singh


    Shotgun proteomics is a powerful technology for global analysis of proteins and their post-translational modifications. Here, we investigate faster sequencing speed of the latest Q Exactive HF mass spectrometer, which features an ultra-high-field Orbitrap mass analyzer. Proteome coverage is evalu......Shotgun proteomics is a powerful technology for global analysis of proteins and their post-translational modifications. Here, we investigate faster sequencing speed of the latest Q Exactive HF mass spectrometer, which features an ultra-high-field Orbitrap mass analyzer. Proteome coverage...

  2. Education is associated with higher later life IQ scores, but not with faster cognitive processing speed. (United States)

    Ritchie, Stuart J; Bates, Timothy C; Der, Geoff; Starr, John M; Deary, Ian J


    Recent reports suggest a causal relationship between education and IQ, which has implications for cognitive development and aging-education may improve cognitive reserve. In two longitudinal cohorts, we tested the association between education and lifetime cognitive change. We then tested whether education is linked to improved scores on processing-speed variables such as reaction time, which are associated with both IQ and longevity. Controlling for childhood IQ score, we found that education was positively associated with IQ at ages 79 (Sample 1) and 70 (Sample 2), and more strongly for participants with lower initial IQ scores. Education, however, showed no significant association with processing speed, measured at ages 83 and 70. Increased education may enhance important later life cognitive capacities, but does not appear to improve more fundamental aspects of cognitive processing. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  3. Competence building capacity shortage

    International Nuclear Information System (INIS)

    Doorman, Gerard; Wangensteen, Ivar; Bakken, Bjoern


    The objective of the project 'Competence Building Capacity Shortage' has been 'to increase knowledge about central approaches aimed at solving the peaking capacity problem in restructured power systems'. With respect to reserve markets, a model was developed in the project to analyze the relations between reserve requirements and prices in the spot and reserve markets respectively. A mathematical model was also developed and implemented, which also includes the balance market, and has a good ability to predict the relations between these markets under various assumptions. With some further development, this model can be used fore realistic analyses of these markets in a Nordic context. It was also concluded that certain system requirements with respect to frequency and time deviation can be relaxed without adverse effects. However, the requirements to system bias, Frequency Activated Operating Reserves and Frequency Activated Contingency Reserves cannot be relaxed, the latter because they must cover the dimensioning fault in the system. On the other hand, Fast Contingency Reserves can be reduced by removing requirements to national balances. Costs can furthermore be reduced by increasingly adapting a Nordic as opposed to national approach. A model for stepwise power flow was developed in the project, which is especially useful to analyze slow power system dynamics. This is relevant when analysing the effects of reserve requirements. A model for the analysis of the capacity balance in Norway and Sweden was also developed. This model is useful for looking at the future balance under various assumptions regarding e.g. weather conditions, demand growth and the development of the generation system. With respect to the present situation, if there is some price flexibility on the demand side and system operators are able to use reserves from the demand side, the probability for load shedding during the peak load hour is close to zero under the weather conditions after

  4. PET/CT Biograph trademark Sensation 16. Performance improvement using faster electronics

    International Nuclear Information System (INIS)

    Martinez, M.J.; Schwaiger, M.; Ziegler, S.I.; Bercier, Y.


    Aim: the new PET/CT biograph sensation 16 (BS16) tomographs have faster detector electronics which allow a reduced timing coincidence window and an increased lower energy threshold (from 350 to 400 keV). This paper evaluates the performance of the BS16 PET scanner before and after the Pico-3D electronics upgrade. Methods: four NEMA NU 2-2001 protocols, (i) spatial resolution, (ii) scatter fraction, count losses and random measurement, (iii) sensitivity, and (iv) image quality, have been performed. Results: a considerable change in both PET count-rate performance and image quality is observed after electronics upgrade. The new scatter fraction obtained using Pico-3D electronics showed a 14% decrease compared to that obtained with the previous electronics. At the typical patient background activity (5.3 kBq/ml), the new scatter fraction was approximately 0.42. The noise equivalent count-rate (R NEC ) performance was also improved. The value at which the R NEC curve peaked, increased from 3.7 . 10 4 s -1 at 14 kBq/ml to 6.4 . 10 4 s -1 at 21 kBq/ml (2R-NEC rate). Likewise, the peak true count-rate value increased from 1.9 . 10 5 s -1 at 22 kBq/ml to 3.4 . 10 5 s -1 at 33 kBq/ml. An average increase of 45% in contrast was observed for hot spheres when using AW-OSEM (4ix8s) as the reconstruction algorithm. For cold spheres, the average increase was 12%. Conclusion: the performance of the PET scanners in the BS16 tomographs is improved by the optimization of the signal processing. The narrower energy and timing coincidence windows lead to a considerable increase of signal-to-noise ratio. The existing combination of fast detectors and adapted electronics in the BS16 tomographs allow imaging protocols with reduced acquisition time, providing higher patient throughput. (orig.)

  5. Are OPERA neutrinos faster than light because of non-inertial reference frames? (United States)

    Germanà, C.


    Context. Recent results from the OPERA experiment reported a neutrino beam traveling faster than light. The challenging experiment measured the neutrino time of flight (TOF) over a baseline from the CERN to the Gran Sasso site, concluding that the neutrino beam arrives ~60 ns earlier than a light ray would do. Because the result, if confirmed, has an enormous impact on science, it might be worth double-checking the time definitions with respect to the non-inertial system in which the neutrino travel time was measured. An observer with a clock measuring the proper time τ free of non-inertial effects is the one located at the solar system barycenter (SSB). Aims: Potential problems in the OPERA data analysis connected with the definition of the reference frame and time synchronization are emphasized. We aim to investigate the synchronization of non-inertial clocks on Earth by relating this time to the proper time of an inertial observer at SSB. Methods: The Tempo2 software was used to time-stamp events observed on the geoid with respect to the SSB inertial observer time. Results: Neutrino results from OPERA might carry the fingerprint of non-inertial effects because they are timed by terrestrial clocks. The CERN-Gran Sasso clock synchronization is accomplished by applying corrections that depend on special and general relativistic time dilation effects at the clocks, depending on the position of the clocks in the solar system gravitational well. As a consequence, TOF distributions are centered on values shorter by tens of nanoseconds than expected, integrating over a period from April to December, longer if otherwise. It is worth remarking that the OPERA runs have always been carried out from April/May to November. Conclusions: If the analysis by Tempo2 holds for the OPERA experiment, the excellent measurement by the OPERA collaboration will turn into a proof of the general relativity theory in a weak field approximation. The analysis presented here is falsifiable

  6. Linking potential heat source and sink to urban heat island: Heterogeneous effects of landscape pattern on land surface temperature. (United States)

    Li, Weifeng; Cao, Qiwen; Lang, Kun; Wu, Jiansheng


    Rapid urbanization has significantly contributed to the development of urban heat island (UHI). Regulating landscape composition and configuration would help mitigate the UHI in megacities. Taking Shenzhen, China, as a case study area, we defined heat source and heat sink and identified strong and weak sources as well as strong and weak sinks according to the natural and socioeconomic factors influencing land surface temperature (LST). Thus, the potential thermal contributions of heat source and heat sink patches were differentiated. Then, the heterogeneous effects of landscape pattern on LST were examined by using semiparametric geographically weighted regression (SGWR) models. The results showed that landscape composition has more significant effects on thermal environment than configuration. For a strong source, the percentage of patches has a positive impact on LST. Additionally, when mosaicked with some heat sink, even a small improvement in the degree of dispersion of a strong source helps to alleviate UHI. For a weak source, the percentage and density of patches have positive impacts on LST. For a strong sink, the percentage, density, and degree of aggregation of patches have negative impacts on LST. The effects of edge density and patch shape complexity vary spatially with the fragmentation of a strong sink. Similarly, the impacts of a weak sink are mainly exerted via the characteristics of percent, density, and shape complexity of patches. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. The Effect of a Piezoelectric Fan on Forced Air Heat Transfer in a Pin-Fin Heat Sink

    Directory of Open Access Journals (Sweden)

    Tzer-Ming Jeng


    Full Text Available An investigation was carried out on the effect of airflow from the blade of a piezoelectric fan on the main cooling airflow across a pin-fin heat sink. The study considered the respective orientation and distances between the piezoelectric blade and the heat sink in a rectangular channel where the airflow was uniform and axial. Three different pin-fin heat sinks with in-line pin-fin arrays were used: 5´5, 7´7 and 9´9. Variable parameters included the Reynolds number of the main airflow and the relative position of the piezoelectric blade and the heat sink. The results showed that the smaller the horizontal distance between the blade and the heat sink, or the greater the vertical distance between the piezoelectric blade and the channel floor, the better the total heat transfer enhancement. Of the three heat sinks used, the 9´9 unit coupled with transverse oscillation of the piezoelectric blade had a slightly higher heat-transfer ratio enhancement. The heat-transfer enhancement ratio Nu/Nu0 (Nu0 is the Nusselt number of the system without the piezoelectric blade will gradually approach 1 with an increase of the Reynolds number of the main flow. At ReL=1200, and with the assistance of the piezoelectric blade, the maximum value of Nu/Nu0 for the 9´9 pin-fin heat sink exceeded 2.

  8. The relationship between grain boundary structure, defect mobility, and grain boundary sink efficiency (United States)

    Uberuaga, Blas Pedro; Vernon, Louis J.; Martinez, Enrique; Voter, Arthur F.


    Nanocrystalline materials have received great attention due to their potential for improved functionality and have been proposed for extreme environments where the interfaces are expected to promote radiation tolerance. However, the precise role of the interfaces in modifying defect behavior is unclear. Using long-time simulations methods, we determine the mobility of defects and defect clusters at grain boundaries in Cu. We find that mobilities vary significantly with boundary structure and cluster size, with larger clusters exhibiting reduced mobility, and that interface sink efficiency depends on the kinetics of defects within the interface via the in-boundary annihilation rate of defects. Thus, sink efficiency is a strong function of defect mobility, which depends on boundary structure, a property that evolves with time. Further, defect mobility at boundaries can be slower than in the bulk, which has general implications for the properties of polycrystalline materials. Finally, we correlate defect energetics with the volumes of atomic sites at the boundary. PMID:25766999

  9. Sources and sinks of diversification and conservation priorities for the Mexican tropical dry forest. (United States)

    Becerra, Judith X; Venable, D Lawrence


    Elucidating the geographical history of diversification is critical for inferring where future diversification may occur and thus could be a valuable aid in determining conservation priorities. However, it has been difficult to recognize areas with a higher likelihood of promoting diversification. We reconstructed centres of origin of lineages and identified areas in the Mexican tropical dry forest that have been important centres of diversification (sources) and areas where species are maintained but where diversification is less likely to occur (diversity sinks). We used a molecular phylogeny of the genus Bursera, a dominant member of the forest, along with information on current species distributions. Results indicate that vast areas of the forest have historically functioned as diversity sinks, generating few or no extant Bursera lineages. Only a few areas have functioned as major engines of diversification. Long-term preservation of biodiversity may be promoted by incorporation of such knowledge in decision-making.

  10. Monitoring the risk of loss of heat sink during plant shutdowns at Bruce Generating Station 'A'

    International Nuclear Information System (INIS)

    Krishnan, K.S.; Mancuso, F.; Vecchiarelli, D.


    A relatively simple loss of shutdown heat sink fault tree model has been developed and used during unit outages at Bruce Nuclear Generation Station 'A' to assess, from a risk and reliability perspective, alternative heat sink strategies and to aid in decisions on allowable outage configurations. The model is adjusted to reflect the various unit configurations planned during a specific outage, and identifies events and event combinations leading to loss of fuel cooling. The calculated failure frequencies are compared to the limits consistent with corporate and international public safety goals. The importance measures generated by the interrogation of the fault tree model for each outage configuration are also used to reschedule configurations with high fuel damage frequency later into the outage and to control the configurations with relatively high probability of fuel damage to short intervals at the most appropriate time into the outage. (author)

  11. Solving the Single-Sink, Fixed-Charge, Multiple-Choice Transportation Problem by Dynamic Programming

    DEFF Research Database (Denmark)

    Christensen, Tue; Andersen, Kim Allan; Klose, Andreas


    This paper considers a minimum-cost network flow problem in a bipartite graph with a single sink. The transportation costs exhibit a staircase cost structure because such types of transportation cost functions are often found in practice. We present a dynamic programming algorithm for solving...... this so-called single-sink, fixed-charge, multiple-choice transportation problem exactly. The method exploits heuristics and lower bounds to peg binary variables, improve bounds on flow variables, and reduce the state-space variable. In this way, the dynamic programming method is able to solve large...... instances with up to 10,000 nodes and 10 different transportation modes in a few seconds, much less time than required by a widely used mixed-integer programming solver and other methods proposed in the literature for this problem....

  12. Solving the Single-Sink, Fixed-Charge, Multiple-Choice Transportation Problem by Dynamic Programming

    DEFF Research Database (Denmark)

    Rauff Lind Christensen, Tue; Klose, Andreas; Andersen, Kim Allan

    The Single-Sink, Fixed-Charge, Multiple-Choice Transportation Problem (SSFCMCTP) is a problem with versatile applications. This problem is a generalization of the Single-Sink, Fixed-Charge Transportation Problem (SSFCTP), which has a fixed-charge, linear cost structure. However, in at least two...... are neglected in the SSFCTP. The SSFCMCTP overcome this problem by incorporating a staircase cost structure in the cost function instead of the usual one used in SSFCTP. We present a dynamic programming algorithm for the resulting problem. To enhance the performance of the generic algorithm a number...... of enhancements is employed. The problem instance is reduced by variable pegging using a Lagrangean relaxation from which also a flow augmentation scheme is derived. Additionally a reduction in the search space is employed along with a variable transformation which generalizes a transformation known from...

  13. Fluid-cooled heat sink for use in cooling various devices

    Energy Technology Data Exchange (ETDEWEB)

    Bharathan, Desikan; Bennion, Kevin; Kelly, Kenneth; Narumanchi, Sreekant


    The disclosure provides a fluid-cooled heat sink having a heat transfer base, a shroud, and a plurality of heat transfer fins in thermal communication with the heat transfer base and the shroud, where the heat transfer base, heat transfer fins, and the shroud form a central fluid channel through which a forced or free cooling fluid may flow. The heat transfer pins are arranged around the central fluid channel with a flow space provided between adjacent pins, allowing for some portion of the central fluid channel flow to divert through the flow space. The arrangement reduces the pressure drop of the flow through the fins, optimizes average heat transfer coefficients, reduces contact and fin-pin resistances, and reduces the physical footprint of the heat sink in an operating environment.

  14. Microplastics Alter the Properties and Sinking Rates of Zooplankton Faecal Pellets. (United States)

    Cole, Matthew; Lindeque, Penelope K; Fileman, Elaine; Clark, James; Lewis, Ceri; Halsband, Claudia; Galloway, Tamara S


    Plastic debris is a widespread contaminant, prevalent in aquatic ecosystems across the globe. Zooplankton readily ingest microscopic plastic (microplastic, microplastics on faecal pellet properties are currently unknown. Here we test the hypotheses that (1) faecal pellets are a vector for transport of microplastics, (2) polystyrene microplastics can alter the properties and sinking rates of zooplankton egests and, (3) faecal pellets can facilitate the transfer of plastics to coprophagous biota. Following exposure to 20.6 μm polystyrene microplastics (1000 microplastics mL(-1)) and natural prey (∼1650 algae mL(-1)) the copepod Calanus helgolandicus egested faecal pellets with significantly (P microplastics, encapsulated within egests of the copepod Centropages typicus, could be transferred to C. helgolandicus via coprophagy. Our results support the proposal that sinking faecal matter represents a mechanism by which floating plastics can be vertically transported away from surface waters.

  15. Sinking/floatation of pipelines and other objects in liquefied soil under waves

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Fredsøe, Jørgen; Christensen, S.


    the experiments with the structure model, the displacement of the structure (sinking or floatation) was measured simultaneously with the pore-water pressure. The influence of various parameters (such as the initial position of the object, the specific gravity, the soil layer thickness, and the wave height......, and the experiments with the structure model (a pipeline, a sphere, and a cube). In the former experiments, the pore-water pressure was measured across the soil depth. The pore-water pressure built up, as the waves progressed. The soil was liquefied for wave heights larger than a critical value. Regarding......) was investigated. It was found that while the pipe sank in the soil to a depth of 2-3 times the pipe diameter, the sphere sank to even larger depths. The pipe with a relatively small specific gravity, initially buried, floated to the surface of the soil. The drag coefficients for the objects sinking...

  16. Viscoelastic Fluid over a Stretching Sheet with Electromagnetic Effects and Nonuniform Heat Source/Sink

    Directory of Open Access Journals (Sweden)

    Kai-Long Hsiao


    Full Text Available A magnetic hydrodynamic (MHD of an incompressible viscoelastic fluid over a stretching sheet with electric and magnetic dissipation and nonuniform heat source/sink has been studied. The buoyant effect and the electric number E1 couple with magnetic parameter M to represent the dominance of the electric and magnetic effects, and adding the specific item of nonuniform heat source/sink is presented in governing equations which are the main contribution of this study. The similarity transformation, the finite-difference method, Newton method, and Gauss elimination method have been used to analyze the present problem. The numerical solutions of the flow velocity distributions, temperature profiles, and the important wall unknown values of f''(0 and θ'(0 have been carried out. The parameter Pr, E1, or Ec can increase the heat transfer effects, but the parameter M or A* may decrease the heat transfer effects.

  17. Sources and sinks of diversification and conservation priorities for the Mexican tropical dry forest.

    Directory of Open Access Journals (Sweden)

    Judith X Becerra

    Full Text Available Elucidating the geographical history of diversification is critical for inferring where future diversification may occur and thus could be a valuable aid in determining conservation priorities. However, it has been difficult to recognize areas with a higher likelihood of promoting diversification. We reconstructed centres of origin of lineages and identified areas in the Mexican tropical dry forest that have been important centres of diversification (sources and areas where species are maintained but where diversification is less likely to occur (diversity sinks. We used a molecular phylogeny of the genus Bursera, a dominant member of the forest, along with information on current species distributions. Results indicate that vast areas of the forest have historically functioned as diversity sinks, generating few or no extant Bursera lineages. Only a few areas have functioned as major engines of diversification. Long-term preservation of biodiversity may be promoted by incorporation of such knowledge in decision-making.

  18. Saturation of the Southern Ocean CO2 sink due to recent climate change

    International Nuclear Information System (INIS)

    Le Quere, C.; Rodenbeck, C.; Buitenhuis, E.T.; Heimann, M.; Le Quere, C.; Buitenhuis, E.T.; Le Quere, C.; Conway, T.J.; Langenfelds, R.; Gomez, A.; Labuschagne, C.; Ramonet, M.; Nakazawa, Takakiyo; Metzl, N.; Gillett, N.


    Based on observed atmospheric carbon dioxide (CO 2 ) concentration and an inverse method, we estimate that the Southern Ocean sink of CO 2 has weakened between 1981 and 2004 by 0.08 peta-grams of carbon per year per decade relative to the trend expected from the large increase in atmospheric CO 2 . We attribute this weakening to the observed increase in Southern Ocean winds resulting from human activities, which is projected to continue in the future. Consequences include a reduction of the efficiency of the Southern Ocean sink of CO 2 in the short term (about 25 years) and possibly a higher level of stabilization of atmospheric CO 2 on a multi-century time scale. (authors)

  19. The importance of mines for ultimate storage at Deilmann-Haniel Shaft Sinking

    International Nuclear Information System (INIS)

    Greinacher, Jochen; Oellers, Thomas; Ahlbrecht, Thomas


    Deilmann-Haniel Shaft Sinking GmbH and its predecessor and associate companies have been involved in projects for underground ultimate storage in Germany, Europe and America for over 45 years. The field of activities previously comprised surveying, planning and sinking of shafts, repair and conversion work, design of underground sealing structures, planning of conveyors and support of the BfS in planning approval procedures. Following discontinuation of activities in the German coal mining industry the use of mines for ultimate storage is an important support for German specialist mining companies. The use of mines for ultimate storage ensures that the existing mining know how in Germany is maintained, because training of the younger generation on the commercial and engineering side of the companies is made possible by the imminent major projects.

  20. A comparison of micro-structured flat-plate and cross-cut heat sinks for thermoelectric generation application

    International Nuclear Information System (INIS)

    Rezania, A.; Rosendahl, L.A.


    Highlights: • Plate-fin and cross-cut heat sinks (PFHS, CCHS) are compared for TEG application. • The three-dimensional governing equations for flow and thermoelectrics are solved. • Power generation, pumping power and optimal thermoelectric net power are studied. • Overall net power in the TEG with PFHS is slightly superior to that with CCHS. • Results are in a good agreement with the previous computational studies. - Abstract: Heat sink configuration has strong impact on net power output from thermoelectric generators (TEGs). A weak cooling strategy can even cause negative net power output from the thermoelectric device. However, the net power output can be significantly improved by optimal design of the heat sink. In this study, a micro-structured plate-fin heat sink is compared to a modified design of cross-cut heat sink applied to TEGs over a range of temperatures and thermal conductivities. The particular focus of this study is to explore the net power output from the TEG module. The three-dimensional governing equations for the flow and heat transfer are solved using computational fluid dynamics (CFD) in conjunction with the thermoelectric characteristics of the TEG over a wide range of flow inlet velocities. The results show that at small flow inlet velocity, the maximum net power output in TEG with plate-fin heat sink is higher, while the TEG with cross-cut heat sink has higher maximum net power output at high flow inlet velocity. The maximum net power output is equal in the TEGs with plate-fin heat sink and cross-cut heat sink