WorldWideScience

Sample records for net virtual water

  1. Net zero water

    CSIR Research Space (South Africa)

    Lindeque, M

    2013-01-01

    Full Text Available the national grid. The unfortunate situation with water is that there is no replacement technology for water. Water can be supplied from many different sources. A net zero energy development will move closer to a net zero water development by reducing...

  2. Virtual scarce water in China.

    Science.gov (United States)

    Feng, Kuishuang; Hubacek, Klaus; Pfister, Stephan; Yu, Yang; Sun, Laixiang

    2014-07-15

    Water footprints and virtual water flows have been promoted as important indicators to characterize human-induced water consumption. However, environmental impacts associated with water consumption are largely neglected in these analyses. Incorporating water scarcity into water consumption allows better understanding of what is causing water scarcity and which regions are suffering from it. In this study, we incorporate water scarcity and ecosystem impacts into multiregional input-output analysis to assess virtual water flows and associated impacts among 30 provinces in China. China, in particular its water-scarce regions, are facing a serious water crisis driven by rapid economic growth. Our findings show that inter-regional flows of virtual water reveal additional insights when water scarcity is taken into account. Consumption in highly developed coastal provinces is largely relying on water resources in the water-scarce northern provinces, such as Xinjiang, Hebei, and Inner Mongolia, thus significantly contributing to the water scarcity in these regions. In addition, many highly developed but water scarce regions, such as Shanghai, Beijing, and Tianjin, are already large importers of net virtual water at the expense of water resource depletion in other water scarce provinces. Thus, increasingly importing water-intensive goods from other water-scarce regions may just shift the pressure to other regions, but the overall water problems may still remain. Using the water footprint as a policy tool to alleviate water shortage may only work when water scarcity is taken into account and virtual water flows from water-poor regions are identified.

  3. Water Footprint and Virtual Water Trade of Brazil

    Directory of Open Access Journals (Sweden)

    Vicente de Paulo R. da Silva

    2016-11-01

    Full Text Available Freshwater scarcity has increased at an alarming rate worldwide; improved water management plays a vital role in increasing food production and security. This study aims to determine the water footprint of Brazil’s national food consumption, the virtual water flows associated with international trade in the main agricultural commodities, as well as water scarcity, water self-sufficiency and water dependency per Brazilian region. While previous country studies on water footprints and virtual water trade focused on virtual water importers or water-scarce countries, this is the first study to concentrate on a water-abundant virtual water-exporting country. Besides, it is the first study establishing international virtual water trade balances per state, which is relevant given the fact that water scarcity varies across states within the country, so the origin of virtual water exports matters. The results show that the average water footprint of Brazilian food consumption is 1619 m3/person/year. Beef contributes most (21% to this total. We find a net virtual water export of 54.8 billion m3/year, mainly to Europe, which imports 41% of the gross amount of the virtual water exported from Brazil. The northeast, the region with the highest water scarcity, has a net import of virtual water. The southeast, next in terms of water scarcity, shows large virtual water exports, mainly related to the export of sugar. The north, which has the most water, does not show a high virtual water export rate.

  4. Virtual water: Virtuous impact? : the unsteady state of virtual water

    NARCIS (Netherlands)

    Roth, D.; Warner, J.F.

    2008-01-01

    Virtual water,” water needed for crop production, is now being mainstreamed in the water policy world. Relying on virtual water in the form of food imports is increasingly recommended as good policy for water-scarce areas. Virtual water globalizes discussions on water scarcity, ecological

  5. Economic aspects of virtual water trade

    Science.gov (United States)

    Oki, Taikan; Yano, Shinjiro; Hanasaki, Naota

    2017-04-01

    Although water is rarely traded over long distances by itself, the total weight of the water consumed to produce traded commodities exceeds the weight of any other commodity traded in the world. This concept is known as virtual water trade. Although space-/time-/commodity-based quantification has been conducted extensively, the underlying causes of this peculiar feature have thus far received little exploration. Here, we use estimates of water consumption from a global hydrological model and statistical data related to food trade to elucidate three facts that explain the fundamental nature of virtual water trade with respect to alleviating water scarcity. First, we quantitatively illustrate the unique position of water among commodities based on its unit price and quantity of sales. Water has an extremely low unit price, and a tremendous volume of water is consumed per person each day. Second, we show that rich but water-scarce countries tend to reduce local water consumption by importing virtual water. Third, we demonstrate that nations characterized by net virtual water exports have higher water resources and income per capita and that no countries fall below a certain threshold with respect to both GDP and water resources. These points suggest that the virtual water trade is explained by economic characteristics of water and that sustainable development depends on promoting the co-development of poverty alleviation and water resource development.

  6. Recent history and geography of virtual water trade.

    Directory of Open Access Journals (Sweden)

    Joel A Carr

    Full Text Available The global trade of goods is associated with a virtual transfer of the water required for their production. The way changes in trade affect the virtual redistribution of freshwater resources has been recently documented through the analysis of the virtual water network. It is, however, unclear how these changes are contributed by different types of products and regions of the world. Here we show how the global patterns of virtual water transport are contributed by the trade of different commodity types, including plant, animal, luxury (e.g., coffee, tea, and alcohol, and other products. Major contributors to the virtual water network exhibit different trade patterns with regard to these commodity types. The net importers rely on the supply of virtual water from a small percentage of the global population. However, discrepancies exist among the different commodity networks. While the total virtual water flux through the network has increased between 1986 and 2010, the proportions associated with the four commodity groups have remained relatively stable. However, some of the major players have shown significant changes in the virtual water imports and exports associated with those commodity groups. For instance, China has switched from being a net exporter of virtual water associated with other products (non-edible plant and animal products typically used for manufacturing to being the largest importer, accounting for 31% of the total water virtually transported with these products. Conversely, in the case of The United states of America, the commodity proportions have remained overall unchanged throughout the study period: the virtual water exports from The United States of America are dominated by plant products, whereas the imports are comprised mainly of animal and luxury products.

  7. Recent History and Geography of Virtual Water Trade

    Science.gov (United States)

    Carr, Joel A.; D’Odorico, Paolo; Laio, Francesco; Ridolfi, Luca

    2013-01-01

    The global trade of goods is associated with a virtual transfer of the water required for their production. The way changes in trade affect the virtual redistribution of freshwater resources has been recently documented through the analysis of the virtual water network. It is, however, unclear how these changes are contributed by different types of products and regions of the world. Here we show how the global patterns of virtual water transport are contributed by the trade of different commodity types, including plant, animal, luxury (e.g., coffee, tea, and alcohol), and other products. Major contributors to the virtual water network exhibit different trade patterns with regard to these commodity types. The net importers rely on the supply of virtual water from a small percentage of the global population. However, discrepancies exist among the different commodity networks. While the total virtual water flux through the network has increased between 1986 and 2010, the proportions associated with the four commodity groups have remained relatively stable. However, some of the major players have shown significant changes in the virtual water imports and exports associated with those commodity groups. For instance, China has switched from being a net exporter of virtual water associated with other products (non-edible plant and animal products typically used for manufacturing) to being the largest importer, accounting for 31% of the total water virtually transported with these products. Conversely, in the case of The United states of America, the commodity proportions have remained overall unchanged throughout the study period: the virtual water exports from The United States of America are dominated by plant products, whereas the imports are comprised mainly of animal and luxury products. PMID:23457481

  8. Recent history and geography of virtual water trade.

    Science.gov (United States)

    Carr, Joel A; D'Odorico, Paolo; Laio, Francesco; Ridolfi, Luca

    2013-01-01

    The global trade of goods is associated with a virtual transfer of the water required for their production. The way changes in trade affect the virtual redistribution of freshwater resources has been recently documented through the analysis of the virtual water network. It is, however, unclear how these changes are contributed by different types of products and regions of the world. Here we show how the global patterns of virtual water transport are contributed by the trade of different commodity types, including plant, animal, luxury (e.g., coffee, tea, and alcohol), and other products. Major contributors to the virtual water network exhibit different trade patterns with regard to these commodity types. The net importers rely on the supply of virtual water from a small percentage of the global population. However, discrepancies exist among the different commodity networks. While the total virtual water flux through the network has increased between 1986 and 2010, the proportions associated with the four commodity groups have remained relatively stable. However, some of the major players have shown significant changes in the virtual water imports and exports associated with those commodity groups. For instance, China has switched from being a net exporter of virtual water associated with other products (non-edible plant and animal products typically used for manufacturing) to being the largest importer, accounting for 31% of the total water virtually transported with these products. Conversely, in the case of The United states of America, the commodity proportions have remained overall unchanged throughout the study period: the virtual water exports from The United States of America are dominated by plant products, whereas the imports are comprised mainly of animal and luxury products.

  9. Local and global perspectives on the virtual water trade

    Directory of Open Access Journals (Sweden)

    S. Tamea

    2013-03-01

    Full Text Available Recent studies on fluxes of virtual water are showing how the global food and goods trade interconnects the water resources of different and distant countries, conditioning the local water balances. This paper presents and discusses the assessment of virtual water fluxes between a single country and its network of trading partners, delineating a country's virtual water budget in space and time (years 1986–2010. The fluxes between the country under study and its importing/exporting partners are visualized with a geographical representation shaping the trade network as a virtual river/delta. Time variations of exchanged fluxes are quantified to show possible trends in the virtual water balance, while characterizing the time evolution of the trade network and its composition in terms of product categories (plant-based, animal-based, luxury food, and non-edible. The average distance traveled by virtual water to arrive to the place of consumption is also introduced as a new measure for the analysis of globalization of the virtual water trade. Using Italy as an example, we find that food trade has a steadily growing importance compared to domestic production, with a major component represented by plant-based products, and luxury products taking an increasingly larger share (26% in 2010. In 2010 Italy had an average net import of 55 km3 of virtual water (38 km3 in 1986, a value which poses the country among the top net importers in the world. On average each cubic meter of virtual water travels nearly 4000 km before entering Italy, while export goes to relatively closer countries (average distance: 2600 km, with increasing trends in time which are almost unique among the world countries. Analyses proposed for Italy are replicated for 10 other world countries, triggering similar investigations on different socio-economic actualities.

  10. Local and global perspectives on the virtual water trade

    Science.gov (United States)

    Tamea, S.; Allamano, P.; Carr, J. A.; Claps, P.; Laio, F.; Ridolfi, L.

    2013-03-01

    Recent studies on fluxes of virtual water are showing how the global food and goods trade interconnects the water resources of different and distant countries, conditioning the local water balances. This paper presents and discusses the assessment of virtual water fluxes between a single country and its network of trading partners, delineating a country's virtual water budget in space and time (years 1986-2010). The fluxes between the country under study and its importing/exporting partners are visualized with a geographical representation shaping the trade network as a virtual river/delta. Time variations of exchanged fluxes are quantified to show possible trends in the virtual water balance, while characterizing the time evolution of the trade network and its composition in terms of product categories (plant-based, animal-based, luxury food, and non-edible). The average distance traveled by virtual water to arrive to the place of consumption is also introduced as a new measure for the analysis of globalization of the virtual water trade. Using Italy as an example, we find that food trade has a steadily growing importance compared to domestic production, with a major component represented by plant-based products, and luxury products taking an increasingly larger share (26% in 2010). In 2010 Italy had an average net import of 55 km3 of virtual water (38 km3 in 1986), a value which poses the country among the top net importers in the world. On average each cubic meter of virtual water travels nearly 4000 km before entering Italy, while export goes to relatively closer countries (average distance: 2600 km), with increasing trends in time which are almost unique among the world countries. Analyses proposed for Italy are replicated for 10 other world countries, triggering similar investigations on different socio-economic actualities.

  11. Virtual water trade and time scales for loss of water sustainability: a comparative regional analysis.

    Science.gov (United States)

    Goswami, Prashant; Nishad, Shiv Narayan

    2015-03-20

    Assessment and policy design for sustainability in primary resources like arable land and water need to adopt long-term perspective; even small but persistent effects like net export of water may influence sustainability through irreversible losses. With growing consumption, this virtual water trade has become an important element in the water sustainability of a nation. We estimate and contrast the virtual (embedded) water trades of two populous nations, India and China, to present certain quantitative measures and time scales. Estimates show that export of embedded water alone can lead to loss of water sustainability. With the current rate of net export of water (embedded) in the end products, India is poised to lose its entire available water in less than 1000 years; much shorter time scales are implied in terms of water for production. The two cases contrast and exemplify sustainable and non-sustainable virtual water trade in long term perspective.

  12. Recent evolution of China's virtual water trade: analysis of selected crops and considerations for policy

    Science.gov (United States)

    Shi, J.; Liu, J.; Pinter, L.

    2014-04-01

    China has dramatically increased its virtual water import over recent years. Many studies have focused on the quantity of traded virtual water, but very few go into analysing geographic distribution and the properties of China's virtual water trade network. This paper provides a calculation and analysis of the crop-related virtual water trade network of China based on 27 major primary crops between 1986 and 2009. The results show that China is a net importer of virtual water from water-abundant areas of North America and South America, and a net virtual water exporter to water-stressed areas of Asia, Africa, and Europe. Virtual water import is far larger than virtual water export, and in both import and export a small number of trade partners control the supply chain. Grain crops are the major contributors to virtual water trade, and among grain crops, soybeans, mostly imported from the US, Brazil and Argentina, are the most significant. In order to mitigate water scarcity and secure the food supply, virtual water should actively be incorporated into national water management strategies. And the sources of virtual water import need to be further diversified to reduce supply chain risks and increase resilience.

  13. Alleviating the water scarcity in the North China Plain: the role of virtual water and real water transfer

    Science.gov (United States)

    Zhang, Zhuoying; Yang, Hong; Shi, Minjun

    2016-04-01

    The North China Plain is the most water scarce region in China. Its water security is closely relevant to interregional water movement, which can be realized by real water transfers and/or virtual water transfers. This study investigates the roles of virtual water trade and real water transfer using Interregional Input-Output model. The results show that the region is receiving 19.4 billion m3/year of virtual water from the interregional trade, while exporting 16.4 billion m3/year of virtual water in the international trade. In balance, the region has a net virtual water gain of 3 billion m3/year from outside. Its virtual water inflow is dominated by agricultural products from other provinces, totalling 16.6 billion m3/year, whilst its virtual water export is dominated by manufacturing sectors to other countries, totalling 11.7 billion m3/year. Both virtual water import and real water transfer from South to North Water Diversion Project are important water supplements for the region. The results of this study provide useful scientific references for the establishment of combating strategies to deal with the water scarcity in the future.

  14. Virtual water and water self-sufficiency in agricultural and livestock products in Brazil.

    Science.gov (United States)

    da Silva, Vicente de Paulo R; de Oliveira, Sonaly D; Braga, Célia C; Brito, José Ivaldo B; de Sousa, Francisco de Assis S; de Holanda, Romildo M; Campos, João Hugo B C; de Souza, Enio P; Braga, Armando César R; Rodrigues Almeida, Rafaela S; de Araújo, Lincoln E

    2016-12-15

    Virtual water trade is often considered a solution for restricted water availability in many regions of the world. Brazil is the world leader in the production and export of various agricultural and livestock products. The country is either a strong net importer or a strong net exporter of these products. The objective of this study is to determine the volume of virtual water contained in agricultural and livestock products imported/exported by Brazil from 1997 to 2012, and to define the water self-sufficiency index of agricultural and livestock products in Brazil. The indexes of water scarcity (WSI), water dependency (WDI) and water self-sufficiency (WSSI) were calculated for each Brazilian state. These indexes and the virtual water balance were calculated following the methodology developed by Chapagain and Hoekstra (2008) and Hoekstra and Hung (2005). The total water exports and imports embedded in agricultural and livestock products were 5.28 × 10 10 and 1.22 × 10 10  Gm 3  yr -1 , respectively, which results in positive virtual water balance of 4.05 × 10 10  Gm 3  yr -1 . Brazil is either a strong net importer or a strong net exporter of agricultural and livestock products among the Mercosur countries. Brazil has a positive virtual water balance of 1.85 × 10 10  Gm 3  yr -1 . The indexes used in this study reveal that Brazil is self-sufficient in food production, except for a few products such as wheat and rice. Horticultural products (tomato, onion, potato, cassava and garlic) make up a unique product group with negative virtual water balance in Brazil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Recent evolution of China's virtual water trade: analysis of selected crops and considerations for policy

    Science.gov (United States)

    Shi, J.; Liu, J.; Pinter, L.

    2013-09-01

    China has dramatically increased its virtual water import unconsciously for recent years. Many studies have focused on the quantity of traded virtual water but very few go into analysing geographic distribution and the properties of China's virtual water trade network. This paper provides a calculation and analysis of the crop-related virtual water trade network of China based on 27 major primary crops between 1986 and 2009. The results show that China is a net importer of virtual water from water-abundant areas of North and South America, and a net virtual water exporter to water-stressed areas of Asia, Africa, and Europe. Virtual water import is far larger than virtual water export and in both import and export a small number of trade partners control the supply chain. Grain crops are the major contributors to virtual water trade, and among grain crops soybeans, mostly imported from the US, Brazil and Argentina are the most significant. As crop yield and crop water productivity in North and South America are generally higher than those in Asia and Africa, the effect of China's crop-related virtual water trade positively contributes to optimizing crop water use efficiency at the global scale. In order to mitigate water scarcity and secure the food supply, virtual water should be actively incorporated into national water management strategies. From the national perspective, China should reduce the export and increase the import of water-intensive crops. But the sources of virtual water import need to be further diversified to reduce supply chain risks and increase resilience.

  16. Understanding virtual water flows: A multiregion input-output case study of Victoria

    Science.gov (United States)

    Lenzen, Manfred

    2009-09-01

    This article explains and interprets virtual water flows from the well-established perspective of input-output analysis. Using a case study of the Australian state of Victoria, it demonstrates that input-output analysis can enumerate virtual water flows without systematic and unknown truncation errors, an issue which has been largely absent from the virtual water literature. Whereas a simplified flow analysis from a producer perspective would portray Victoria as a net virtual water importer, enumerating the water embodiments across the full supply chain using input-output analysis shows Victoria as a significant net virtual water exporter. This study has succeeded in informing government policy in Australia, which is an encouraging sign that input-output analysis will be able to contribute much value to other national and international applications.

  17. OtagoNet: One Region's Model for Virtual Schooling

    Science.gov (United States)

    Pratt, Keryn; Pullar, Ken

    2013-01-01

    Virtual schools are increasingly common in New Zealand and internationally as schools are challenged to meet the needs of their students. This article presents a description of the distance-learning model used by a group of schools in rural Otago for the last decade. The leadership team and roles are described, and the funding model, which is…

  18. Virtual water trade and bilateral conflicts

    Science.gov (United States)

    De Angelis, Enrico; Metulini, Rodolfo; Bove, Vincenzo; Riccaboni, Massimo

    2017-12-01

    In light of growing water scarcity, virtual water, or the water embedded in key water-intensive commodities, has been an active area of debate among practitioners and academics alike. As of yet, however, there is no consensus on whether water scarcity affects conflict behavior and we still lack empirical research intending to account for the role of virtual water in affecting the odds of militarized disputes between states. Using quantitative methods and data on virtual water trade, we find that bilateral and multilateral trade openness reduce the probability of war between any given pair of countries, which is consistent with the strategic role of this important commodity and the opportunity cost associated with the loss of trade gains. We also find that the substantive effect of virtual water trade is comparable to that of oil and gas, the archetypal natural resources, in determining interstate conflicts' probability.

  19. WaterNet: The NASA Water Cycle Solutions Network

    Science.gov (United States)

    Houser, P. R.; Belvedere, D. R.; Pozzi, W. H.; Imam, B.; Schiffer, R.; Lawford, R.; Schlosser, C. A.; Gupta, H.; Welty, C.; Vorosmarty, C.; Matthews, D.

    2007-12-01

    Water is essential to life and directly impacts and constrains society's welfare, progress, and sustainable growth, and is continuously being transformed by climate change, erosion, pollution, and engineering practices. The water cycle is a critical resource for industry, agriculture, natural ecosystems, fisheries, aquaculture, hydroelectric power, recreation, and water supply, and is central to drought, flood, transportation-aviation, and disease hazards. It is therefore a national priority to use advancements in scientific observations and knowledge to develop solutions to the water challenges faced by society. NASA's unique role is to use its view from space to improve water and energy cycle monitoring and prediction. NASA has collected substantial water cycle information and knowledge that must be transitioned to develop solutions for all twelve National Priority Application (NPA) areas. NASA cannot achieve this goal alone -it must establish collaborations and interoperability with existing networks and nodes of research organizations, operational agencies, science communities, and private industry. Therefore, WaterNet: The NASA Water Cycle Solutions Network goal is to improve and optimize the sustained ability of water cycle researchers, stakeholders, organizations and networks to interact, identify, harness, and extend NASA research results to augment decision support tools and meet national needs. WaterNet is a catalyst for discovery and sharing of creative solutions to water problems. It serves as a creative, discovery process that is the entry-path for a research-to-solutions systems engineering NASA framework, with the end result to ultimately improve decision support.

  20. Virtual versus real water transfers within China

    NARCIS (Netherlands)

    Ma, Jing; Hoekstra, Arjen Ysbert; wang, Hao; Chapagain, Ashok; Wang, Dangxian

    2006-01-01

    North China faces severe water scarcity—more than 40% of the annual renewable water resources are abstracted for human use. Nevertheless, nearly 10% of the water used in agriculture is employed in producing food exported to south China. To compensate for this ‘virtual water flow’ and to reduce water

  1. Water Footprint and Virtual Water Trade of Brazil

    OpenAIRE

    da Silva, Vicente de Paulo R.; de Oliveira, Sonaly D.; Hoekstra, Arjen Ysbert; Neto, Jose Dantas; Campos, João Hugo B.C.; Braga, Celia C.; Araújo, Lincoln Eloi; Oliveira Aleixo, Danilo; de Brito, Jose Ivaldo B.; de Souza, Marcio Dionisio; de Holanda, Romildo M.

    2016-01-01

    Freshwater scarcity has increased at an alarming rate worldwide; improved water management plays a vital role in increasing food production and security. This study aims to determine the water footprint of Brazil’s national food consumption, the virtual water flows associated with international trade in the main agricultural commodities, as well as water scarcity, water self-sufficiency and water dependency per Brazilian region. While previous country studies on water footprints and virtual w...

  2. Modeling of water treatment plant using timed continuous Petri nets

    Science.gov (United States)

    Nurul Fuady Adhalia, H.; Subiono, Adzkiya, Dieky

    2017-08-01

    Petri nets represent graphically certain conditions and rules. In this paper, we construct a model of the Water Treatment Plant (WTP) using timed continuous Petri nets. Specifically, we consider that (1) the water pump always active and (2) the water source is always available. After obtaining the model, the flow through the transitions and token conservation laws are calculated.

  3. Linking economic water use, freshwater ecosystem impacts, and virtual water trade in a Great Lakes watershed

    Science.gov (United States)

    Mubako, S. T.; Ruddell, B. L.; Mayer, A. S.

    2013-12-01

    The impact of human water uses and economic pressures on freshwater ecosystems is of growing interest for water resource management worldwide. This case study for a water-rich watershed in the Great Lakes region links the economic pressures on water resources as revealed by virtual water trade balances to the nature of the economic water use and the associated impacts on the freshwater ecosystem. A water accounting framework that combines water consumption data and economic data from input output tables is applied to quantify localized virtual water imports and exports in the Kalamazoo watershed which comprises ten counties. Water using economic activities at the county level are conformed to watershed boundaries through land use-water use relationships. The counties are part of a region implementing the Michigan Water Withdrawal Assessment Process, including new regulatory approaches for adaptive water resources management under a riparian water rights framework. The results show that at local level, there exists considerable water use intensity and virtual water trade balance disparity among the counties and between water use sectors in this watershed. The watershed is a net virtual water importer, with some counties outsourcing nearly half of their water resource impacts, and some outsourcing nearly all water resource impacts. The largest virtual water imports are associated with agriculture, thermoelectric power generation and industry, while the bulk of the exports are associated with thermoelectric power generation and commercial activities. The methodology is applicable to various spatial levels ranging from the micro sub-watershed level to the macro Great Lakes watershed region, subject to the availability of reliable water use and economic data.

  4. The Virtual Water Transactions Promote Environmental Justice?

    Directory of Open Access Journals (Sweden)

    Thaís Dalla Corte

    2016-12-01

    Full Text Available As natural water, virtual water is essential for the dynamics of life. It, that correspond to the total volume of fresh water used in the production process in one place and that was incorporated into the final goods, is a calculation that can contribute to human access to water be assured in sufficient quantities for a dignified life. Therefore, the objective of this research is, through the hypothetical-deductive method of approach, evaluate virtual water transfers from the perspective of environmental justice in a globalized world in the Anthropocene.

  5. [Research on the virtual water composition and virtual water trade for agriculture in Beijing].

    Science.gov (United States)

    Wang, Hong-rui; Wang, Yan; Wang, Jun-hong; Dong, Yan-yan; Han, Zhao-xing

    2007-12-01

    Based on the irrigation norm of typical district and county, and revised by the isoline map of Chinese crops water demand, the change of crops program was analyzed as well as the agricultural water use and its GDP benefits. Then the virtual water was calculated for years. At last, the input-output method was used to calculate the trade of virtual water in Beijing. As the results, the virtual water for cereal crops has been decreasing in Beijing, from 1.832 x 10(9) m3 in 1990 to 4.283 x 10(8) m3 in 2004. Otherwise the virtual water for technical crops has been increasing, which is from 9.06 x 10(8) m3 in 1990 to 1.492 x 10(9) m3 in 2004. On the whole, the virtual water for crops has been decreasing in Beijing. From the angle of primary products Beijing is a virtual water importing area. Virtual water importing of annual average is 2.37 x 10(8) m3, which is about 5.93% of the total water of Beijing. Virtual water has been an important supplement of local real water of Beijing.

  6. Virtual water trade and development in Africa

    Science.gov (United States)

    Konar, Megan; Caylor, Kelly

    2014-05-01

    A debate has long existed on the relationships between human population, natural resources, and development. Recent research has expanded this debate to include the impacts of trade; specifically, virtual water trade, or the water footprint of traded commodities. We conduct an empirical analysis of the relationships between virtual water trade, population, and development in Africa. We find that increases in virtual water imports do not lead to increases in population growth nor do they diminish human welfare. We establish a new index of virtual water trade openness and show that levels of undernourishment tend to fall with increased values of virtual water trade openness. Countries with small dam storage capacity obtain a higher fraction of their agricultural water requirements from external sources, which may indicate implicit `infrastructure sharing' across nations. Globally, increased crop exports tends to correlate with increased crop water use efficiency, though this relationship does not hold for Africa. However, internal African trade is much more efficient in terms of embodied water resources than any other region in the world. Thus, internal African trade patterns may be compensating for poor internal production systems.

  7. Virtual water trade and development in Africa

    Directory of Open Access Journals (Sweden)

    M. Konar

    2013-10-01

    Full Text Available A debate has long existed on the relationships between human population, natural resources, and development. Recent research has expanded this debate to include the impacts of trade; specifically, virtual water trade, or the water footprint of traded commodities. We conduct an empirical analysis of the relationships between virtual water trade, population, and development in Africa. We find that increases in virtual water imports do not lead to increases in population growth nor do they diminish human welfare. We establish a new index of virtual water trade openness and show that levels of undernourishment tend to fall with increased values of virtual water trade openness. Countries with small dam storage capacity obtain a higher fraction of their agricultural water requirements from external sources, which may indicate implicit "infrastructure sharing" across nations. Globally, increased crop exports tend to correlate with increased crop water use efficiency, though this relationship does not hold for Africa. However, internal African trade is much more efficient in terms of embodied water resources than any other region in the world. Thus, internal African trade patterns may be compensating for poor internal production systems.

  8. The virtual water content of major grain crops and virtual water flows between regions in China.

    Science.gov (United States)

    Sun, Shi-Kun; Wu, Pu-Te; Wang, Yu-Bao; Zhao, Xi-Ning

    2013-04-01

    The disproportionate distribution of arable land and water resources has become a bottleneck for guaranteeing food security in China. Virtual water and virtual water trade theory have provided a potential solution to improve water resources management in agriculture and alleviate water crises in water-scarce regions. The present study evaluates the green and blue virtual water content of wheat, maize and rice at the regional scale in China. It then assesses the water-saving benefits of virtual water flows related to the transfer of the three crops between regions. The national average virtual water content of wheat, maize and rice were 1071 m(3) per ton (50.98% green water, 49.02% blue water ), 830 m(3) per ton (76.27% green water, 23.73% blue water) and 1294 m(3) per ton (61.90% green water, 38.10% blue water), respectively. With the regional transfer of wheat, maize and rice, virtual water flows reached 30.08 Gm(3) (59.91% green water, 40.09% blue water). Meanwhile, China saved 11.47 Gm(3) green water, while it consumed 7.84 Gm(3) more blue water than with a no-grain transfer scenario in 2009. In order to guarantee food security in China, the government should improve water productivity (reduce virtual water content of crops) during the grain production process. Meanwhile, under the preconditions of economic feasibility and land-water resources availability, China should guarantee the grain-sown area in southern regions for taking full advantage of green water resources and to alleviate the pressure on water resources. © 2012 Society of Chemical Industry.

  9. Virtual versus real water transfers within China

    Science.gov (United States)

    Ma, Jing; Hoekstra, Arjen Y; Wang, Hao; Chapagain, Ashok K; Wang, Dangxian

    2005-01-01

    North China faces severe water scarcity—more than 40% of the annual renewable water resources are abstracted for human use. Nevertheless, nearly 10% of the water used in agriculture is employed in producing food exported to south China. To compensate for this ‘virtual water flow’ and to reduce water scarcity in the north, the huge south–north Water Transfer Project is currently being implemented. This paradox—the transfer of huge volumes of water from the water-rich south to the water-poor north versus transfer of substantial volumes of food from the food-sufficient north to the food-deficit south—is receiving increased attention, but the research in this field has not yet reached further than rough estimation and qualitative description. The aim of this paper is to review and quantify the volumes of virtual water flows between the regions in China and to put them in the context of water availability per region. The analysis shows that north China annually exports about 52 billion m3 of water in virtual form to south China, which is more than the maximum proposed water transfer volume along the three routes of the Water Transfer Project from south to north. PMID:16767828

  10. A Method for Modeling the Virtual Instrument Automatic Test System Based on the Petri Net

    Institute of Scientific and Technical Information of China (English)

    MA Min; CHEN Guang-ju

    2005-01-01

    Virtual instrument is playing the important role in automatic test system. This paper introduces a composition of a virtual instrument automatic test system and takes the VXIbus based a test software platform which is developed by CAT lab of the UESTC as an example. Then a method to model this system based on Petri net is proposed. Through this method, we can analyze the test task scheduling to prevent the deadlock or resources conflict. At last, this paper analyzes the feasibility of this method.

  11. Virtual water trade of agricultural products: A new perspective to explore the Belt and Road.

    Science.gov (United States)

    Zhang, Yu; Zhang, Jin-He; Tian, Qing; Liu, Ze-Hua; Zhang, Hong-Lei

    2018-05-01

    The Belt and Road is an initiative of cooperation and development that was proposed by China. Moreover, most of the spanning countries faced water shortages and agriculture consumed a lot of water. Virtual water links water, food and trade and is an effective tool to ease water shortages. Therefore, this paper aims to understand the Belt and Road from the new perspective of virtual water trade of agricultural products. We considered agricultural products trade from 2001 to 2015. On the whole, the results indicated that China was in virtual water trade surplus with the countries along the Belt and Road. However, in terms of each country, >40 spanning countries were in virtual water trade surplus with China and eased water shortages. Russia had the largest net imported virtual water from China. Furthermore, the proportion of the grey water footprint that China exported to the spanning countries was much higher than that imported, no matter from the whole or different geographical regions. Moreover, more than half of the countries' virtual water trade with China conformed to the virtual water strategy, which helped to ease water crises. Furthermore, the products that they exported to China were mainly advantageous products that each spanning countries have. Virtual water trade is a new perspective to explore the Belt and Road. Agricultural products trade with China definitely benefits both the countries along the Belt and Road and China from the perspective of virtual water. The findings are beneficial for the water management of the countries along the Belt and Road and China, alleviating water shortages, encouraging the rational allocation of water resources in the various departments. They can provide references for optimizing trade structures as well. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Virtual water exported from Californian agriculture

    Science.gov (United States)

    Nicholas, K. A.; Johansson, E. L.

    2015-12-01

    In an increasingly teleconnected world, international trade drives the exchange of virtual land and water as crops produced in one region are consumed in another. In theory, this can be an optimal use of scarce resources if crops are grown where they can most efficiently be produced. Several recent analyses examine the export of land and water from food production in developing countries where these resources may be more abundant. Here we focus on a developed region and examine the virtual export of land and water from California, the leading agricultural state in the US and the leading global producer of a wide range of fruit, nut, and other specialty crops. As the region faces a serious, ongoing drought, water use is being questioned, and water policy governance re-examined, particularly in the agricultural sector which uses over three-quarters of water appropriations in the state. We look at the blue water embodied in the most widely grown crops in California and use network analysis to examine the trading patterns for flows of virtual land and water. We identify the main crops and export partners representing the majority of water exports. Considered in the context of tradeoffs for land and water resources, we highlight the challenges and opportunities for food production systems to play a sustainable role in meeting human needs while protecting the life-support systems of the planet.

  13. Virtual water flows in the international trade of agricultural products of China.

    Science.gov (United States)

    Zhang, Yu; Zhang, Jinhe; Tang, Guorong; Chen, Min; Wang, Lachun

    2016-07-01

    With the rapid development of the economy and population, water scarcity and poor water quality caused by water pollution have become increasingly severe in China. Virtual water trade is a useful tool to alleviate water shortage. This paper focuses on a comprehensive study of China's international virtual water flows from agricultural products trade and completes a diachronic analysis from 2001 to 2013. The results show that China was in trade surplus in relation to the virtual water trade of agricultural products. The exported virtual water amounted to 29.94billionm(3)/yr. while 155.55billionm(3)/yr. was embedded in imported products. The trend that China exported virtual water per year was on the decline while the imported was on a rising trend. Virtual water trade of China was highly concentrated. Not all of the exported products had comparative advantages in virtual water content. Imported products were excessively concentrated on water intensive agricultural products such as soya beans, cotton, and palm oil. The exported virtual water mainly flowed to the Republic of Korea, Hong Kong of China and Japan, while the imported mainly flowed from the United States of America, Brazil and Argentina. From the ethical point of view, the trade partners were classified into four types in terms of "net import" and "water abundance": mutual benefit countries, such as Australia and Canada; unilateral benefit countries, such as Mongolia and Norway; supported countries, such as Egypt and Singapore; and double pressure countries, such as India and Pakistan. Virtual water strategy refers to water resources, agricultural products and human beings. The findings are beneficial for innovating water resources management system, adjusting trade structure, ensuring food security in China, and promoting the construction of national ecological security system. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Application of virtual water trade theory in interregional grain ...

    African Journals Online (AJOL)

    Application of virtual water trade theory in interregional grain allocation and ... was calculated in 2008 based on virtual water and virtual water trade theories. ... The whole country saved about 3.05×1010m³ water resource as a result of the well ...

  15. Water Footprint and Virtual Water Trade of Brazil

    NARCIS (Netherlands)

    da Silva, Vicente de Paulo R.; de Oliveira, Sonaly D.; Hoekstra, Arjen Ysbert; Neto, Jose Dantas; Campos, João Hugo B.C.; Braga, Celia C.; Araújo, Lincoln Eloi; Oliveira Aleixo, Danilo; de Brito, Jose Ivaldo B.; de Souza, Marcio Dionisio; de Holanda, Romildo M.

    2016-01-01

    Freshwater scarcity has increased at an alarming rate worldwide; improved water management plays a vital role in increasing food production and security. This study aims to determine the water footprint of Brazil’s national food consumption, the virtual water flows associated with international

  16. Worse than imagined: Unidentified virtual water flows in China.

    Science.gov (United States)

    Cai, Beiming; Wang, Chencheng; Zhang, Bing

    2017-07-01

    The impact of virtual water flows on regional water scarcity in China had been deeply discussed in previous research. However, these studies only focused on water quantity, the impact of virtual water flows on water quality has been largely neglected. In this study, we incorporate the blue water footprint related with water quantity and grey water footprint related with water quality into virtual water flow analysis based on the multiregional input-output model of 2007. The results find that the interprovincial virtual flows accounts for 23.4% of China's water footprint. The virtual grey water flows are 8.65 times greater than the virtual blue water flows; the virtual blue water and grey water flows are 91.8 and 794.6 Gm 3 /y, respectively. The use of the indicators related with water quantity to represent virtual water flows in previous studies will underestimate their impact on water resources. In addition, the virtual water flows are mainly derived from agriculture, chemical industry and petroleum processing and the coking industry, which account for 66.8%, 7.1% and 6.2% of the total virtual water flows, respectively. Virtual water flows have intensified both quantity- and quality-induced water scarcity of export regions, where low-value-added but water-intensive and high-pollution goods are produced. Our study on virtual water flows can inform effective water use policy for both water resources and water pollution in China. Our methodology about virtual water flows also can be used in global scale or other countries if data available. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. The role of scarcity in global virtual water flows

    OpenAIRE

    Lenzen, Manfred; Bhaduri, Anik; Moran, Daniel; Kanemoto, Keiichiro; Bekchanov, Maksud

    2012-01-01

    Recent analyses of the evolution and structure of trade in virtual water revealed that the number of trade connections and volume of virtual water trade have more than doubled over the past two decades, and that developed countries increasingly draw on the rest of the world to alleviate the pressure on their domestic water resources. Our work builds on these studies, but fills three important gaps in the research on global virtual water trade. First, we note that in previous studies virtual w...

  18. U-Net/SLE: A Java-Based User-Customizable Virtual Network Interface

    Directory of Open Access Journals (Sweden)

    Matt Welsh

    1999-01-01

    Full Text Available We describe U‐Net/SLE (Safe Language Extensions, a user‐level network interface architecture which enables per‐application customization of communication semantics through downloading of user extension applets, implemented as Java classfiles, to the network interface. This architecture permits applications to safely specify code to be executed within the NI on message transmission and reception. By leveraging the existing U‐Net model, applications may implement protocol code at the user level, within the NI, or using some combination of the two. Our current implementation, using the Myricom Myrinet interface and a small Java Virtual Machine subset, allows host communication overhead to be reduced and improves the overlap of communication and computation during protocol processing.

  19. Recent work on network application layer: MioNet, the virtual workplace for small businesses

    Science.gov (United States)

    Hesselink, Lambertus; Rizal, Dharmarus; Bjornson, Eric; Miller, Brian; Chan, Keith

    2005-11-01

    Small businesses must be extremely efficient and smartly leverage their resources, suppliers, and partners to successfully compete with larger firms. A successful small business requires a set of companies with interlocking business relationships that are dynamic and needs-based. There has been no software solution that creates a secure and flexible way to efficiently connect small business computer-based employees and partners. In this invited paper, we discuss MioNet, a secure and powerful data management platform which may provide millions of small businesses with a virtual workplace and help them to succeed.

  20. (Virtual) Water-repellent Law? Why Legal Studies Should Be Brought Into the Virtual Water Debate

    Science.gov (United States)

    Turrini, Paolo

    2014-05-01

    Virtual water studies are a marvelous example of the much praised "interdisciplinary approach", efficaciously intertwining many threads woven by scholars of very diverse fields of research. After all, if water is an object of biological interest and the word "virtual" becomes especially significant in the framework of the international trade flows, why should agronomists and economists not work together? And, with them, hydrologists, environmental engineers, network analysis experts… either working side by side or, at least, following one another's steps. Browsing the relevant academic literature one may notice that a vast array of disciplines is dealing with the topic. As a consequence, it may come as a surprise that lawyers seem to have remained almost deaf to the charming call of virtual water. A social science thoroughly "social" even if sometimes deemed (also by its practitioners) akin to humanities - and for this reason not always timely in catching the hints by hard sciences - law has a lot to say about virtual water and its manifold aspects. And it is so, in my opinion, in at least two respects. First of all, legal provisions can be determinants of social facts no less than other types of norms, such as physical or economic laws. Law shapes the human behavior by giving incentives or establishing constraints to the conduct of virtually any kind of social actor, be they farmers needing to decide what to grow, entrepreneurs willing to invest in the water market, or governments requested to address their communities' problems. All of them will make their choices in consideration of the costs, opportunities, and limits set by a number of regulations. In the second place, and strictly connected with the first reason, law may offer some answers to the challenges that virtual water and, more in general, the water-food nexus bring with them. In fact, understanding the way legal provisions affect the taking of decisions in the water sector, one may try to devise

  1. Drivers and Effects of Virtual Water Cycling

    Science.gov (United States)

    D'Odorico, P.

    2016-12-01

    The increasing global demand for farmland products by the growing and increasingly burgeoning human population is placing unprecedented pressure on the global agricultural system and its water resources. Many regions of the world that are not self-sufficient because of their chronic water scarcity or lack of suitable agricultural land strongly depend on the importation of agricultural commodities and associated embodied (or "virtual") water. International trade, however, may become unreliable when the supplies in the international food market are scarce. As a result, transboundary investments in agricultural land have become a priority for a number of governments and corporations that are trying to expand their agricultural production while securing good profits. This global "land rush" is often driven by the need for a secure access to water resources for agriculture. The globalization of water and land through trade and foreign land acquisitions is leading to a displacement of land use and a disconnection between human populations and the water resources they rely on. Despite the recognized importance of these phenomena in reshaping the patterns of water dependency through teleconnections between consumer behavior and production areas, their effect on global and regional food security, remains poorly quantified. New teleconnections are also emerging from the increasing water use for energy production. Competition in water use for food and energy security constitutes the core of an emerging debate that is generating new questions on the environmental, ethical, economic, and policy implications of human appropriation of water resources. This lecture will examine the ways societies virtually modify their access to water through trade and foreign land acquisitions to meet their growing food and energy needs.

  2. The Politics and Consequences of Virtual Water Export

    NARCIS (Netherlands)

    Vos, J.; Boelens, R.A.; Jackson, P.; Spiess, W.E.L.; Sultana, F.

    2016-01-01

    Virtual water is the water used or contaminated to produce a good or a service. With the large increase of export of agricultural produce during the last decades the amount of virtual water export has grown as well. Increased water contamination and water extraction for export from relative dry

  3. (Virtual) Water Flows Uphill toward Money.

    Science.gov (United States)

    Wang, Ranran; Hertwich, Edgar; Zimmerman, Julie B

    2016-11-15

    This study provides a more precise understanding of the main driving forces of anthropogenic water use across countries. The anthropogenic water use was distinguished as blue water (i.e., fresh surface and groundwater) and total water (i.e. blue + green water; green water is rainwater insofar as it does not become runoff) used for producing, consuming, exporting, and importing of primary and manufactured goods and services, measured on a per country and per capita basis. The population effect on national blue water consumption associated with producing and consuming was found to be bigger than what the commonly assumed unitary population elasticity indicates. Distinct from the homogeneous affluence-water relationships conventionally assumed, this study revealed varying and potentially opposite effects affluence can have depending on the water use account of interest (e.g., production-based or consumption-based, blue or green) and the income level. Affluence, not the availability of freshwater resources, was found to be the most critical driver of virtual water imports. And a more affluent lifestyle in high-income countries was still associated with greater blue water consumption. With each doubling of income, blue water embedded in the goods and services a nation consumed and imported on a per capita basis increased by 82% and 86%, respectively, across the 110 countries analyzed for 2007. In comparison to affluence, the varying per capita water consumption accounts across the nations were much less sensitive to food consumption patterns. Given its critical role for water, land, and energy use shown by this and previous studies, affluence should be taken as a critical factor in future studies to better understand and leverage the water-energy-food-land nexus.

  4. Globalisation of water: opportunities and threats of virtual water trade

    NARCIS (Netherlands)

    Chapagain, A.K.

    2006-01-01

    Where the river basin is generally seen as the appropriate unit for analyzing freshwater availability and use, it becomes increasingly important to put freshwater issues in a global context. The book analyses the opportunities and threats of international virtual water trade in the context of

  5. Propagation of crises in the virtual water trade network

    Science.gov (United States)

    Tamea, Stefania; Laio, Francesco; Ridolfi, Luca

    2015-04-01

    The international trade of agricultural goods is associated to the displacement of the water used to produce such goods and embedded in trade as a factor of production. Water virtually exchanged from producing to consuming countries, named virtual water, defines flows across an international network of 'virtual water trade' which enable the assessment of environmental forcings and implications of trade, such as global water savings or country dependencies on foreign water resources. Given the recent expansion of commodity (and virtual water) trade, in both displaced volumes and network structure, concerns have been raised about the exposure to crises of individuals and societies. In fact, if one country had to markedly decrease its export following a socio-economical or environmental crisis, such as a war or a drought, many -if not all- countries would be affected due to a cascade effect within the trade network. The present contribution proposes a mechanistic model describing the propagation of a local crisis into the virtual water trade network, accounting for the network structure and the virtual water balance of all countries. The model, built on data-based assumptions, is tested on the real case study of the Argentinean crisis in 2008-09, when the internal agricultural production (measured as virtual water volume) decreased by 26% and the virtual water export of Argentina dropped accordingly. Crisis propagation and effects on the virtual water trade are correctly captured, showing the way forward to investigations of crises impact and country vulnerability based on the results of the model proposed.

  6. [Distribution of virtual water of crops in Beijing].

    Science.gov (United States)

    Wang, Hong-Rui; Dong, Yan-Yan; Wang, Jun-Hong; Wang, Yan; Han, Zhao-Xing

    2007-11-01

    Virtual water content of grains and vegetables in Beijing's districts is calculated and analyzed for many years by irrigating water quota method, which is compared with the distribution and exploitation of groundwater in Beijing. The results indicate the virtual water content of grains shows a downward trend in all the districts, but the grain production in Yanqing district brings great pressure to the local groundwater. Secondly, the virtual water content of vegetables shows an upward trend in Shunyi District, Daxing district and Pinggu District and is accounting for more and more gradually. Thirdly, the total virtual water volume of grains is decreasing, and the total virtual water volume of vegetables is increasing and the total virtual water volume of crops in Beijing is reducing in recent years, which corresponds with the structural adjustment of policies.

  7. [Virtual water content of livestock products in China].

    Science.gov (United States)

    Wang, Hong-rui; Wang, Jun-hong

    2006-04-01

    The paper expatiated the virtual water content concept of livestock products and the study meaning on developing virtual water trade of livestock products in China, then summarized the calculation methods on virtual water and virtual water trade of livestock products. Based on these, the paper analyzed and researched every province virtual water content of livestock products in details, then elicited various situation of every province virtual water content of livestock products in China by year. Moreover, it compared virtual water content of livestock products with local water resources. The study indicated the following results: (1) The virtual water content of livestock products is increasing rapidly in China recently, especially poultry eggs and pork. (2) The distribution of virtual water content of livestock products is not balanced, mainly lies in North China, East China and so on; (3) The increasing production of livestock in Beijing City, Tianjin City, Hebei, Nei Monggol, Liaononing, Jilin, Shandong, Henan and Ningxia province and autonom ous region will bring pressure to local water shortage.

  8. Stroking the Net Whale: A Constructivist Grounded Theory of Self-Regulated Learning in Virtual Social Spaces

    Science.gov (United States)

    Kasperiuniene, Judita; Zydziunaite, Vilma; Eriksson, Malin

    2017-01-01

    This qualitative study explored the self-regulated learning (SRL) of teachers and their students in virtual social spaces. The processes of SRL were analyzed from 24 semi-structured individual interviews with professors, instructors and their students from five Lithuanian universities. A core category stroking the net whale showed the process of…

  9. Upper Primary Students Constructing and Exploring Three Dimensional Shapes: A Comparison of Virtual Reality with Card Nets.

    Science.gov (United States)

    Ainge, David J.

    1996-01-01

    A grade 6/7 class which constructed and explored three-dimensional shapes with the VREAM virtual reality (VR) development system program was compared with a grade 5/6/7 control group using card nets (diagrams which can be cut out/folded). Results indicated that VR had little impact on shape visualization and name writing, but it strongly enhanced…

  10. Water Sustainability Assessments for Four Net Zero Water Installations

    Science.gov (United States)

    2013-12-01

    average daily water use, in six leaks. While the cost of the lost water might seem insignificant using current valuation methods, the financial impacts...One function of GFEBS is to identify facility maintenance requirements through integrated asset valuation and depreciation. The desired outcome is...considers tapping groundwater reservoirs as an additional water source. The most feasible groundwater source would likely originate in an alluvial valley

  11. Determinants of virtual water flows in the Mediterranean.

    Science.gov (United States)

    Fracasso, Andrea; Sartori, Martina; Schiavo, Stefano

    2016-02-01

    The aim of the paper is to investigate the main determinants of the bilateral virtual water (water used in the production of a commodity or service) flows associated with international trade in agricultural goods across the Mediterranean basin. We consider the bilateral gross flows of virtual water in the area and study what export-specific and import-specific factors are significantly associated with virtual water flows. We follow a sequential approach. Through a gravity model of trade, we obtain a "refined" version of the variable we aim to explain, one that is free of the amount of flows due to pair-specific factors affecting bilateral trade flows and that fully reflects the impact of country-specific determinants of virtual water trade. A number of country-specific potential explanatory variables, ranging from water endowments to trade barriers, from per capita GDP to irrigation prices, is presented and tested. To identify the variables that help to explain the bilateral flows of virtual water, we adopt a model selection procedure based on model averaging. Our findings confirm one of the main controversial results in the literature: larger water endowments do not necessarily lead to a larger 'export' of virtual water, as one could expect. We also find some evidence that higher water irrigation prices reduce (increase) virtual water 'exports' ('imports'). Copyright © 2015 Elsevier B.V. All rights reserved.

  12. WaterNet: The NASA water cycle solutions network - Danubian regional applications

    International Nuclear Information System (INIS)

    Matthews, Dave; Brilly, Mitja; Kobold, Mira; Zagar, Mark; Houser, Paul

    2008-01-01

    WaterNet is a new international network of researchers, stakeholders, and end-users of remote sensing tools that will benefit the water resources management community. This paper provides an overview and it discusses the concept of solutions networks focusing on the WaterNet. It invites Danubian research and applications teams to join our WaterNet network. The NASA Water cycle Solutions Network's goal is to improve and optimize the sustained ability of water cycle researchers, stakeholders, organizations and networks to interact, identify, harness, and extend NASA research results to augment decision support tools and meet national needs. Our team will develop WaterNet by engaging relevant NASA water cycle research resources and community-of-practice organizations, to develop what we term an 'actionable database' that can be used to communicate and connect NASA Water cycle research Results (NWRs) towards the improvement of water-related Decision Support Tools (DSTs). Recognizing that the European Commission and European Space Agency have also developed many related Water Research products (EWRs), we seek to learn about these and network with the EU teams to include their information in the WaterNet actionable data base and Community of Practice. WaterNet will then develop strategies to connect researchers and decision-makers via innovative communication strategies, improved user access to NASA and EU - Danubian resources, improved water cycle research community appreciation for user requirements, improved policymaker, management and stakeholder knowledge of research and application products, and improved identification of pathways for progress. Finally, WaterNet will develop relevant benchmarking and metrics, to understand the network's characteristics, to optimize its performance, and to establish sustainability. This paper provides examples of several NASA products based on remote sensing and land data assimilation systems that integrate remotely sensed and in

  13. Globalisation of water resources: International virtual water flows in relation to international crop trade

    NARCIS (Netherlands)

    Hoekstra, Arjen Ysbert; Hung, P.Q.

    2005-01-01

    The water that is used in the production process of a commodity is called the ‘virtual water’ contained in the commodity. International trade of commodities brings along international flows of virtual water. The objective of this paper is to quantify the volumes of virtual water flows between

  14. Virtual water embodied in international trade of soybean

    DEFF Research Database (Denmark)

    Caro, Dario; Thomsen, Marianne

    This study focuses on hidden water flows embodied in the international trade of soybean. The virtual water content embedded in soybean imported and exported by 174 countries during the period 2000-2013 is estimated.......This study focuses on hidden water flows embodied in the international trade of soybean. The virtual water content embedded in soybean imported and exported by 174 countries during the period 2000-2013 is estimated....

  15. Virtual water trade: an assessment of water use efficiency in the international food trade

    Directory of Open Access Journals (Sweden)

    H. Yang

    2006-01-01

    Full Text Available Amid an increasing water scarcity in many parts of the world, virtual water trade as both a policy instrument and practical means to balance the local, national and global water budget has received much attention in recent years. Building upon the knowledge of virtual water accounting in the literature, this study assesses the efficiency of water use embodied in the international food trade from the perspectives of exporting and importing countries and at the global and country levels. The investigation reveals that the virtual water flows primarily from countries of high crop water productivity to countries of low crop water productivity, generating a global saving in water use. Meanwhile, the total virtual water trade is dominated by green virtual water, which constitutes a low opportunity cost of water use as opposed to blue virtual water. A sensitivity analysis, however, suggests high uncertainties in the virtual water accounting and the estimation of the scale of water saving. The study also raises awareness of the limited effect of water scarcity on the global virtual water trade and the negative implications of the global water saving for the water use efficiency and food security in importing countries and the environment in exporting countries. The analysis shows the complexity in evaluating the efficiency gains in the international virtual water trade. The findings of the study, nevertheless, call for a greater emphasis on rainfed agriculture to improve the global food security and environmental sustainability.

  16. Evolution of the global virtual water trade network.

    Science.gov (United States)

    Dalin, Carole; Konar, Megan; Hanasaki, Naota; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio

    2012-04-17

    Global freshwater resources are under increasing pressure from economic development, population growth, and climate change. The international trade of water-intensive products (e.g., agricultural commodities) or virtual water trade has been suggested as a way to save water globally. We focus on the virtual water trade network associated with international food trade built with annual trade data and annual modeled virtual water content. The evolution of this network from 1986 to 2007 is analyzed and linked to trade policies, socioeconomic circumstances, and agricultural efficiency. We find that the number of trade connections and the volume of water associated with global food trade more than doubled in 22 years. Despite this growth, constant organizational features were observed in the network. However, both regional and national virtual water trade patterns significantly changed. Indeed, Asia increased its virtual water imports by more than 170%, switching from North America to South America as its main partner, whereas North America oriented to a growing intraregional trade. A dramatic rise in China's virtual water imports is associated with its increased soy imports after a domestic policy shift in 2000. Significantly, this shift has led the global soy market to save water on a global scale, but it also relies on expanding soy production in Brazil, which contributes to deforestation in the Amazon. We find that the international food trade has led to enhanced savings in global water resources over time, indicating its growing efficiency in terms of global water use.

  17. Evaluation of Virtual Water Trade by the Industrial Sector of Zanjan Province

    Directory of Open Access Journals (Sweden)

    Morteza Tahami Pourzarandi

    2017-07-01

    Full Text Available Water crisis is of utmost importance due to the growing demand and consumption of water, especially in developing countries where its production and food security are facing serious challenges. Virtual water trade has been proposed as one strategy to combat the water scarcity crisis in arid and semi-arid regions. The strategy is based on the import of food and water-intensive supplies from neighboring regions that enjoy adequate supplies of water. Given the fact that the industrial sector has been proposed to serve as the basis of development in Zanjan Province, the present study was conducted to investigate the virtual water trade by the industrial sector in this province. For the purposes of this study, data from the statistical period 2010-2011 were obtained from the Statistical Center of Iran on enterprises employing ten member staffs or above. The data were used to categorize the industries surveyed, their water demands, and products to estimate the quantities of water needed for their continued operation. It was found that the highest quantities of virtual water in Zanjan are allocated to coking and petroleum plants, paper and cellulosic industries, and food and beverage processing factories with average values of 32.70, 26.14, and 11.63 cubic meters per million Rials, respectively. In addition, the total amount of virtual water exported from the industrial units operating in Zanjan Province is estimated at about 3.10 MCM, 50% of which belongs to base metal production. Conclusion: Our findings show that the industrial sector in Zanjan Province is a net exporter of virtual water.

  18. Virtuous and vicious virtual water trade with application to Italy.

    Directory of Open Access Journals (Sweden)

    Julia Anna Winter

    Full Text Available The current trade of agricultural goods, with connections involving all continents, entails for global exchanges of "virtual" water, i.e. water used in the production process of alimentary products, but not contained within. Each trade link translates into a corresponding virtual water trade, allowing quantification of import and export fluxes of virtual water. The assessment of the virtual water import for a given nation, compared to the national consumption, could give an approximate idea of the country's reliance on external resources from the food and the water resources point of view. A descriptive approach to the understanding of a nation's degree of dependency from overseas food and water resources is first proposed, and indices of water trade virtuosity, as opposed to inefficiency, are devised. Such indices are based on the concepts of self-sufficiency and relative export, computed systematically on all products from the FAOSTAT database, taking Italy as the first case study. Analysis of time series of the self-sufficiency and relative export can demonstrate effects of market tendencies and influence water-related policies at the international level. The goal of this approach is highlighting incongruent terms in the virtual water balances by the viewpoint of single products. Specific products, which are here referred to as "swap products", are in fact identified as those that lead to inefficiencies in the virtual water balance due to their contemporaneously high import and export. The inefficiencies due to the exchanges of the same products between two nations are calculated in terms of virtual water volumes. Furthermore, the cases of swap products are investigated by computing two further indexes denoting the ratio of virtual water exchanged in the swap and the ratio of the economic values of the swapped products. The analysis of these figures can help examine the reasons behind the swap phenomenon in trade.

  19. Virtuous and vicious virtual water trade with application to Italy.

    Science.gov (United States)

    Winter, Julia Anna; Allamano, Paola; Claps, Pierluigi

    2014-01-01

    The current trade of agricultural goods, with connections involving all continents, entails for global exchanges of "virtual" water, i.e. water used in the production process of alimentary products, but not contained within. Each trade link translates into a corresponding virtual water trade, allowing quantification of import and export fluxes of virtual water. The assessment of the virtual water import for a given nation, compared to the national consumption, could give an approximate idea of the country's reliance on external resources from the food and the water resources point of view. A descriptive approach to the understanding of a nation's degree of dependency from overseas food and water resources is first proposed, and indices of water trade virtuosity, as opposed to inefficiency, are devised. Such indices are based on the concepts of self-sufficiency and relative export, computed systematically on all products from the FAOSTAT database, taking Italy as the first case study. Analysis of time series of the self-sufficiency and relative export can demonstrate effects of market tendencies and influence water-related policies at the international level. The goal of this approach is highlighting incongruent terms in the virtual water balances by the viewpoint of single products. Specific products, which are here referred to as "swap products", are in fact identified as those that lead to inefficiencies in the virtual water balance due to their contemporaneously high import and export. The inefficiencies due to the exchanges of the same products between two nations are calculated in terms of virtual water volumes. Furthermore, the cases of swap products are investigated by computing two further indexes denoting the ratio of virtual water exchanged in the swap and the ratio of the economic values of the swapped products. The analysis of these figures can help examine the reasons behind the swap phenomenon in trade.

  20. 'Virtual Water' - Real People: Useful Concept or Prescriptive Tool?

    NARCIS (Netherlands)

    Warner, J.F.; Johnson, C.L.

    2007-01-01

    The 'virtual water' thesis is beginning to take centre stage in the water security global discourse. From its origins as a conceptual tool for countering the gloomy Malthusian ('water scarcity leads to water wars') argument, it is now increasingly seen as a serious prescriptive tool for the

  1. Managing Water Sustainability: Virtual Water Flows and Economic Water Productivity Assessment of the Wine Trade between Italy and the Balkans

    Directory of Open Access Journals (Sweden)

    Pier Paolo Miglietta

    2018-02-01

    Full Text Available The management of natural resources in economic activities has become a fundamental issue when considering the perspective of sustainable development. It is necessary to rethink every process in order to reach efficiency from different points of view, not only environmentally but also economically. Water scarcity is growing because of economic and population growth, climate change, and the increasing water demand. Currently, agri-food represents the most water consumptive sector, and the increasing importance of international trade in this industry puts freshwater issues in a global context that should be analyzed and regulated by sustainable policies. This analysis is focused on virtual water flows and economic water productivity related to the wine trade, and aims to evaluate water loss/savings achieved through bilateral trade relations. The choice fell on Italy, the first wine producer in the world, and the Balkan countries. The latter are new markets for wine production/consumption, in which Italian wines are strongly positioned for different reasons. The results show that, from a national point of view and considering wine trade, Italy exports water in virtual form to the Balkan countries, more than it imports, so that in effect it partially uses its own water resources for the wine supply of the Balkans. The latter, on the other hand, being a net importer of wine, partially depends on Italian water resources and exerts less pressure on their own water basins in the supporting wine supply. We also observed that the wine trade between Italy and the Balkans implies global water savings.

  2. Virtual Water and Food Security in Tunisia | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... on the world grain market has social implications for Tunisia's small farmers and ... Thus, when a country exports an agricultural product, in effect it also exports ... Tunisia that incorporates the virtual water concept in a food security strategy.

  3. Can virtual water 'trade' reduce water scarcity in semi-arid countries? The case of Spain

    OpenAIRE

    Garrido, Alberto; Novo, Paula; Rodriguez Casado, Roberto; Varela-Ortega, Consuelo

    2009-01-01

    Agricultural trade is by far the largest vehicle to ‘move’ water virtually around the world. Observing that most countries import and export water embedded in the exchanged products, the objective of this study is to assess the virtual water ‘trade’ in Spain for the period 1997-2006. We differentiate between the green and blue components of virtual water from a hydrological and economic perspective. The combination of spatial and time dimensions offers a unique empirical setting to determine ...

  4. Business Profile of Boat Lift Net and Stationary Lift Net Fishing Gear in Morodemak Waters Central Java

    Science.gov (United States)

    Hapsari, Trisnani D.; Jayanto, Bogi B.; Fitri, Aristi D. P.; Triarso, I.

    2018-02-01

    Lift net is one of the fishing gears that is used widely in the Morodemak coastal fishing port (PPP) for catching pelagic fish. The yield of fish captured by these fishing gear has high economic value, such as fish belt (Trichiurus sp), squids (Loligo sp) and anchovies (Stelophorus sp). The aims of this research were to determine the technical aspects of boat lift net and stationary lift net fishing gear in Morodemak Waters Demak Regency; to find out the financial aspect of those fishing gears and to analyze the financial feasibility by counting PP, NPV, IRR, and B/C ratio criteria. This research used case study method with descriptive analysis. The sampling method was purposive sampling with 22 fishermen as respondents. The result of the research showed that the average of boat lift net acceptance was Rp 388,580,000. The financial analysis of fisheries boat lift net with the result of NPV Rp 836,149,272, PP 2.44 years, IRR value 54%, and B/C ratio 1.73. The average of stationary lift net acceptance was Rp 27,750,000. The financial analysis lift net with the result of NPV Rp 37,937,601; PP 1.96 years, IRR value 86%, and B/C ratio 1.32. This research had a positive NPV value, B/C ratio >1, and IRR > discount rate (12 %). This study concluded that the fishery business of boat lift net and stationary lift net in Morodemak coastal fishing port (PPP) was worth running.

  5. Water footprint, extended water footprint and virtual water trade of the Cantabria region, Spain. A critical appraisal of results, uncertainties and methods.

    Science.gov (United States)

    Diaz-Alcaide, Silvia; Martinez-Santos, Pedro; Willaarts, Barbara; Hernández-Moreno, Enrique; Llamas, M. Ramon

    2015-04-01

    Water footprint assessments have gradually gained recognition as valuable tools for water management, to the point that they have been officially incorporated to water planning in countries such as Spain. Adequate combinations of the virtual water and water footprint concepts present the potential to link a broad range of sectors and issues, thus providing appropriate frameworks to support optimal water allocation and to inform production and trade decisions from the water perspective. We present the results of a regional study carried out in Cantabria, a 5300 km2 autonomous region located in northern Spain. Our approach deals with the municipal, shire and regional scales, combining different methods to assess each of the main components of Cantabria's water footprint (agriculture, livestock, forestry, industry, mining, tourism, domestic use and reservoirs), as well as exploring the significance of different approaches, assumptions and databases in the overall outcomes. The classic water footprint method is coupled with extended water footprint analyses in order to provide an estimate of the social and economic value of each sector. Finally, virtual water imports and exports are computed between Cantabria and the rest of Spain and between Cantabria and the world. The outcome of our work (a) highlights the paramount importance of green water (mostly embedded in pastures) in the region's water footprint and virtual water exports; (b) establishes the role of the region as a net virtual water exporter; (c) shows the productivity of water (euro/m3 and jobs/m3) to be highest in tourism and lowest in agriculture and livestock; and (d) demonstrates that statistical databases are seldom compiled with water footprint studies in mind, which is likely to introduce uncertainties in the results. Although our work shows that there is still plenty of room for improvement in regional-scale water footprint assessments, we contend that the available information is sufficient to

  6. Assessment of interstate virtual water flows embedded in agriculture to mitigate water scarcity in India (1996-2014)

    Science.gov (United States)

    Katyaini, Suparana; Barua, Anamika

    2017-08-01

    India is the largest global freshwater user despite being highly water scarce. Agriculture is largest consumer of water and is most affected by water scarcity. Water scarcity is a persistent challenge in India, due to a gap in science and policy spheres. Virtual Water (VW) flows concept to mitigate water scarcity is at the science-policy interface. The paper aims to address the gap in VW research in India by first analyzing the interstate VW-flows embedded in food grains, and then linking these VW-flows with the water scarcity situation in the states, and elements of state and national water policies for the postreforms, and recovery periods of India's agriculture. There were net water savings (WS) of 207.5 PL during 1996-2014, indicating sustainable flows at the national level. WS increased from 11.2 TL/yr (1996-2005) to 25931.7 TL/yr (2005-2014), with the increase in interstate movement of food grains, and yield. However, unsustainable flows are seen at subnational scale, as VW-flows are from highly water-scarce states in North to highly water-scarce states in West and South. These flows are causing a concentration of water scarcity in water-scarce zones/states. Net VW imports were found to be driven by larger population and net VW exports by arable land. Further, the absence of state water policy cripples water management. Therefore, the paper argues that there is a need to rethink policy decisions on agriculture at the national and state level by internalizing water as a factor of production, through VW research.

  7. Entropy of Egypt's virtual water trade gravity field

    Science.gov (United States)

    Karakatsanis, Georgios; Bierbach, Sandra

    2016-04-01

    The study investigates the entropy of Egypt's virtual water trade gravity distribution, in order to provide a chart of Egypt's embodied water balance in agricultural trade, in relation to distances with its major counterparties. Moreover, our calculations on the amount of the embodied water traded between Egypt and each of its partners take place according to a combination of available data on the blue, green and grey water footprints as well as the Food and Agriculture Organization (FAO) database of traded amounts per crop type. A study on the virtual water trade gravity, enables us to enrich former related studies (Fracasso 2014; Fracasso, Sartori and Schiavo 2014) via examining Egypt's water supply dependence on the Nile River and if comparative advantages -purely from the side of water quantities- can be identified via recognizing which water footprint categories are particularly high. Additionally, this methodology can comprise -from a fundamental level- a guide for revealing the importance of water footprint types for Egypt's agricultural sector; hence, Egypt's potential comparative advantages, as far as quantitative water endowments are exclusively concerned (without consideration of water or crop prices). Although it is pointed out very correctly by various authors (Antonelli and Sartori 2014) that the virtual water trade concept does not incorporate many important aspects of water supply -such as heavy water price subsidizing- to be used accurately for the identification of comparative advantages, we consider that the purely quantitative examination can provide strong fundamental indications -especially for green and grey water footprints, which are hypothesized to be less sensitive to subsidizing. In overall, this effect can very well provide a primary indication on the organization of the global alimentation trade network (Yang et al. 2006). The gravity equation used contains water footprint data for the 15 top traded crops and the distances for Egypt

  8. Incorporating the water footprint and virtual water into policy: reflections from the Mancha Occidental Region, Spain

    NARCIS (Netherlands)

    Martinez-Aldaya, Maite; Martínez-Santos, Pedro; Llamas, M. Ramón

    2010-01-01

    Water resource management is often a controversial issue in semiarid regions. Most water resources experts admit that water conflicts are not caused by the physical water scarcity but they are mainly due to inadequate water management. The virtual water concept (the volume of water used in the

  9. Temporal dynamics of blue and green virtual water trade networks

    Science.gov (United States)

    Konar, M.; Dalin, C.; Hanasaki, N.; Rinaldo, A.; Rodriguez-Iturbe, I.

    2012-12-01

    Global food security increasingly relies on the trade of food commodities. Freshwater resources are essential to agricultural production and are thus embodied in the trade of food commodities, referred to as "virtual water trade." Agricultural production predominantly relies on rainwater (i.e., "green water"), though irrigation (i.e., "blue water") does play an important role. These different sources of water have distinctly different opportunity costs, which may be reflected in the way these resources are traded. Thus, the temporal dynamics of the virtual water trade networks from these distinct water sources require characterization. We find that 42 × 109 m3 blue and 310 × 109 m3 green water was traded in 1986, growing to 78 × 109 m3 blue and 594 × 109 m3 green water traded in 2008. Three nations dominate the export of green water resources: the USA, Argentina, and Brazil. As a country increases its export trade partners it tends to export relatively more blue water. However, as a country increases its import trade partners it does not preferentially import water from a specific source. The amount of virtual water that a country imports by increasing its import trade partners has been decreasing over time, with the exception of the soy trade. Both blue and green virtual water networks are efficient: 119 × 109 m3 blue and 105 × 109 m3 green water were saved in 2008. Importantly, trade has been increasingly saving water over time, due to the intensification of crop trade on more water-efficient links.

  10. Intra-EU agricultural trade, virtual water flows and policy implications.

    Science.gov (United States)

    Antonelli, M; Tamea, S; Yang, H

    2017-06-01

    The development of approaches to tackle the European Union (EU) water-related challenges and shift towards sustainable water management and use is one of the main objectives of Horizon 2020, the EU strategy to lead a smart, sustainable and inclusive growth. The EU is an increasingly water challenged area and is a major agricultural trader. As agricultural trade entails an exchange of water embodied in goods as a factor of production, this study investigates the region's water-food-trade nexus by analysing intra-regional virtual water trade (VWT) in agricultural products. The analysed period (1993-2011) comprises the enactment of the Water Framework Directive (WFD) in the year 2000. Aspects of the VWT that are relevant for the WFD are explored. The EU is a net importer of virtual water (VW) from the rest of the world, but intra-regional VWT represents 46% of total imports and 75% of total exports. Five countries account for 60% of total VW imports (Germany, France, Italy, The Netherlands, Belgium) and 65% of total VW exports (The Netherlands, France, Germany, Belgium and Spain). Intra-EU VWT more than doubled over the period considered, while trade with extra-EU countries did not show such a marked trend. In the same period, blue VWT increased significantly within the region and net import from the rest of the world slightly decreased. Water scarce countries, such as Spain and Italy, are major exporters of blue water in the region. The traded volumes of VW have been increasing almost monotonically over the years, and with a substantial increase after 2000. The overall trend in changes in VWT does not seem to be in accordance with the WFD goals. This study demonstrated that VWT analyses can help evaluate intertwining effects of water, agriculture and trade policies which are often made separately in respective sectors. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. The trade of virtual water: do property rights matter?

    Science.gov (United States)

    Xu, Ankai

    2016-04-01

    My paper examines the determinants of the virtual water trade - embodied in the trade of agriculture products - by estimating a structural gravity model. In particular, it tests the relationship between property rights and the export of water-intensive agricultural products based on water footprint data in Mekonnen and Hoekstra (2011, 2012). Using two different measures of property rights protection, I show that countries with weaker property rights have an apparent comparative advantage in the trade of water-intensive products. After controlling for the economic size, natural resource endowments, and possible effects of reverse causality, the trade flow of virtual water is negatively and significantly correlated with the property rights index of the exporting country. Holding other factors constant, one point increase in the property rights index of a country is associated with a 24% - 36% decrease in its virtual water export, whereas a 1% increase in the natural resource protection index of a country is associated with a 16% decrease in its virtual water export. This paper is the first empirical work that tests the relationship between property rights and trade of water-intensive products, offering a new perceptive in the debate of virtual water trade. The findings provide a possible explanation on the paradoxical evidence that some countries with scarce water resources export water-intensive products. The result is important not only in terms of its theoretical relevance, but also its policy implications. As prescribed by the model of trade and property rights, when countries with weaker property rights open to international trade, they are more likely to over-exploit and thus expedite the depletion of natural resources.

  12. Coarse-Grained Model for Water Involving a Virtual Site.

    Science.gov (United States)

    Deng, Mingsen; Shen, Hujun

    2016-02-04

    In this work, we propose a new coarse-grained (CG) model for water by combining the features of two popular CG water models (BMW and MARTINI models) as well as by adopting a topology similar to that of the TIP4P water model. In this CG model, a CG unit, representing four real water molecules, consists of a virtual site, two positively charged particles, and a van der Waals (vdW) interaction center. Distance constraint is applied to the bonds formed between the vdW interaction center and the positively charged particles. The virtual site, which carries a negative charge, is determined by the locations of the two positively charged particles and the vdW interaction center. For the new CG model of water, we coined the name "CAVS" (charge is attached to a virtual site) due to the involvment of the virtual site. After being tested in molecular dynamic (MD) simulations of bulk water at various time steps, under different temperatures and in different salt (NaCl) concentrations, the CAVS model offers encouraging predictions for some bulk properties of water (such as density, dielectric constant, etc.) when compared to experimental ones.

  13. Design of virtual SCADA simulation system for pressurized water reactor

    International Nuclear Information System (INIS)

    Wijaksono, Umar; Abdullah, Ade Gafar; Hakim, Dadang Lukman

    2016-01-01

    The Virtual SCADA system is a software-based Human-Machine Interface that can visualize the process of a plant. This paper described the results of the virtual SCADA system design that aims to recognize the principle of the Nuclear Power Plant type Pressurized Water Reactor. This simulation uses technical data of the Nuclear Power Plant Unit Olkiluoto 3 in Finland. This device was developed using Wonderware Intouch, which is equipped with manual books for each component, animation links, alarm systems, real time and historical trending, and security system. The results showed that in general this device can demonstrate clearly the principles of energy flow and energy conversion processes in Pressurized Water Reactors. This virtual SCADA simulation system can be used as instructional media to recognize the principle of Pressurized Water Reactor

  14. Design of virtual SCADA simulation system for pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wijaksono, Umar, E-mail: umar.wijaksono@student.upi.edu; Abdullah, Ade Gafar; Hakim, Dadang Lukman [Electrical Power System Research Group, Department of Electrical Engineering Education, Jl. Dr. Setiabudi No. 207 Bandung, Indonesia 40154 (Indonesia)

    2016-02-08

    The Virtual SCADA system is a software-based Human-Machine Interface that can visualize the process of a plant. This paper described the results of the virtual SCADA system design that aims to recognize the principle of the Nuclear Power Plant type Pressurized Water Reactor. This simulation uses technical data of the Nuclear Power Plant Unit Olkiluoto 3 in Finland. This device was developed using Wonderware Intouch, which is equipped with manual books for each component, animation links, alarm systems, real time and historical trending, and security system. The results showed that in general this device can demonstrate clearly the principles of energy flow and energy conversion processes in Pressurized Water Reactors. This virtual SCADA simulation system can be used as instructional media to recognize the principle of Pressurized Water Reactor.

  15. Net-bottom Cage Inserts for Water Bird Casualties

    Directory of Open Access Journals (Sweden)

    Jackie Belle

    2017-10-01

    Full Text Available My Bright Idea is a net-bottomed cage insert, which is used to support pelagic avian casualties. The idea was designed and modified by the International Bird Rescue in California (Bird Rescue.

  16. Physical and virtual water transfers for regional water stress alleviation in China.

    Science.gov (United States)

    Zhao, Xu; Liu, Junguo; Liu, Qingying; Tillotson, Martin R; Guan, Dabo; Hubacek, Klaus

    2015-01-27

    Water can be redistributed through, in physical terms, water transfer projects and virtually, embodied water for the production of traded products. Here, we explore whether such water redistributions can help mitigate water stress in China. This study, for the first time to our knowledge, both compiles a full inventory for physical water transfers at a provincial level and maps virtual water flows between Chinese provinces in 2007 and 2030. Our results show that, at the national level, physical water flows because of the major water transfer projects amounted to 4.5% of national water supply, whereas virtual water flows accounted for 35% (varies between 11% and 65% at the provincial level) in 2007. Furthermore, our analysis shows that both physical and virtual water flows do not play a major role in mitigating water stress in the water-receiving regions but exacerbate water stress for the water-exporting regions of China. Future water stress in the main water-exporting provinces is likely to increase further based on our analysis of the historical trajectory of the major governing socioeconomic and technical factors and the full implementation of policy initiatives relating to water use and economic development. Improving water use efficiency is key to mitigating water stress, but the efficiency gains will be largely offset by the water demand increase caused by continued economic development. We conclude that much greater attention needs to be paid to water demand management rather than the current focus on supply-oriented management.

  17. Measuring scarce water saving from interregional virtual water flows in China

    Science.gov (United States)

    Zhao, X.; Li, Y. P.; Yang, H.; Liu, W. F.; Tillotson, M. R.; Guan, D.; Yi, Y.; Wang, H.

    2018-05-01

    Trade of commodities can lead to virtual water flows between trading partners. When commodities flow from regions of high water productivity to regions of low water productivity, the trade has the potential to generate water saving. However, this accounting of water saving does not account for the water scarcity status in different regions. It could be that the water saving generated from this trade occurs at the expense of the intensified water scarcity in the exporting region, and exerts limited effect on water stress alleviation in importing regions. In this paper, we propose an approach to measure the scarce water saving associated with virtual water trade (measuring in water withdrawal/use). The scarce water is quantified by multiplying the water use in production with the water stress index (WSI). We assessed the scarce water saving/loss through interprovincial trade within China using a multi-region input-output table from 2010. The results show that interprovincial trade resulted in 14.2 km3 of water loss without considering water stress, but only 0.4 km3 scarce water loss using the scarce water concept. Among the 435 total connections of virtual water flows, 254 connections contributed to 20.2 km3 of scarce water saving. Most of these connections are virtual water flows from provinces with lower WSI to that with higher WSI. Conversely, 175 connections contributed to 20.6 km3 of scarce water loss. The virtual water flow connections between Xinjiang and other provinces stood out as the biggest contributors, accounting for 66% of total scarce water loss. The results show the importance of assessing water savings generated from trade with consideration of both water scarcity status and water productivity across regions. Identifying key connections of scarce water saving is useful in guiding interregional economic restructuring towards water stress alleviation, a major goal of China’s sustainable development strategy.

  18. Ecological network analysis for a virtual water network.

    Science.gov (United States)

    Fang, Delin; Chen, Bin

    2015-06-02

    The notions of virtual water flows provide important indicators to manifest the water consumption and allocation between different sectors via product transactions. However, the configuration of virtual water network (VWN) still needs further investigation to identify the water interdependency among different sectors as well as the network efficiency and stability in a socio-economic system. Ecological network analysis is chosen as a useful tool to examine the structure and function of VWN and the interactions among its sectors. A balance analysis of efficiency and redundancy is also conducted to describe the robustness (RVWN) of VWN. Then, network control analysis and network utility analysis are performed to investigate the dominant sectors and pathways for virtual water circulation and the mutual relationships between pairwise sectors. A case study of the Heihe River Basin in China shows that the balance between efficiency and redundancy is situated on the left side of the robustness curve with less efficiency and higher redundancy. The forestation, herding and fishing sectors and industrial sectors are found to be the main controllers. The network tends to be more mutualistic and synergic, though some competitive relationships that weaken the virtual water circulation still exist.

  19. Virtual water transfers unlikely to redress inequality in global water use

    International Nuclear Information System (INIS)

    Seekell, D A; D'Odorico, P; Pace, M L

    2011-01-01

    The distribution of renewable freshwater resources between countries is highly unequal and 80% of humanity lives in regions where water security is threatened. The transfer of agricultural and industrial products to areas where water is limited through global trade may have potential for redressing water imbalances. These transfers represent 'virtual water' used in commodity production. We evaluated the current water-use inequality between countries and the potential of virtual water transfers to equalize water use among nations using multiple statistical measures of inequality. Overall, the actual use of renewable water resources is relatively equal even though the physical distribution of renewable water resources is highly unequal. Most inequality (76%) in water use is due to agricultural production and can be attributed to climate and arable land availability, not social development status. Virtual water use is highly unequal and is almost completely explained by social development status. Virtual water transfer is unlikely to increase water-use equality primarily because agricultural water use dominates national water needs and cannot be completely compensated by virtual water transfers.

  20. Virtual water transfers unlikely to redress inequality in global water use

    Energy Technology Data Exchange (ETDEWEB)

    Seekell, D A; D' Odorico, P; Pace, M L [Department of Environmental Sciences, University of Virginia, Charlottesville, VA (United States)

    2011-04-15

    The distribution of renewable freshwater resources between countries is highly unequal and 80% of humanity lives in regions where water security is threatened. The transfer of agricultural and industrial products to areas where water is limited through global trade may have potential for redressing water imbalances. These transfers represent 'virtual water' used in commodity production. We evaluated the current water-use inequality between countries and the potential of virtual water transfers to equalize water use among nations using multiple statistical measures of inequality. Overall, the actual use of renewable water resources is relatively equal even though the physical distribution of renewable water resources is highly unequal. Most inequality (76%) in water use is due to agricultural production and can be attributed to climate and arable land availability, not social development status. Virtual water use is highly unequal and is almost completely explained by social development status. Virtual water transfer is unlikely to increase water-use equality primarily because agricultural water use dominates national water needs and cannot be completely compensated by virtual water transfers.

  1. Transfer of Virtual Water of Woody Forest Products from China

    Directory of Open Access Journals (Sweden)

    Kaisheng Luo

    2018-02-01

    Full Text Available Global freshwater resources are under increasing pressure. It is reported that international trade of water-intensive products (the so-called virtual water trade can be used to ease global water pressure. In spite of the significant amount of international trade of woody forest products, virtual water of woody forest products (VWWFP and the corresponding international trade are largely ignored. However, virtual water research has progressed steadily. This study maps VWWFP and statistically analyzes China’s official data for the period 1993–2014. The results show a rapid increase in the trend of VWWFP flow from China, reaching 7.61 × 1012 m3 or 3.48 times annual virtual water trade for agricultural products. The export and import volumes of China are respectively 1.27 × 1012 m3 and 6.34 × 1012 m3 for 1993–2014. China imported a total of 5.07 × 1012 m3 of VWWFP in 1993–2014 to lessen domestic water pressure, which is five times the annual water transfer via China’s South–North Water Transfer project. Asia and Europe account for the highest contribution (50.52% to China’s import. Other contributors include the Russian Federation (16.63%, Indonesia (13.45%, Canada (13.41%, the United States of America (9.60%, Brazil (7.23% and Malaysia (6.33%. China mainly exports VWWFP to Asia (47.68%, North America (23.24%, and Europe (20.01%. The countries which export the highest amount of VWWFP include the United States of America, Japan, Republic of Korea and Canada. Then the countries which import the highest amount of VWWFP include the Russian Federation, Canada, United States of America, and Brazil. The VWWFP flow study shows an obvious geographical distribution that is driven by proximity and traffic since transportation cost of woody forest products could be significant.

  2. Mineralizing urban net-zero water treatment: Phase II field results and design recommendations

    Science.gov (United States)

    Net-zero water (NZW) systems, or water management systems achieving high recycling rates and low residuals generation so as to avoid water import and export, can also conserve energy used to heat and convey water, while economically restoring local eco-hydrology. However, design ...

  3. Native on the net indigenous and diasporic peoples in the virtual age

    CERN Document Server

    Landzelius, Kyra; Shi, Xianglin

    2004-01-01

    Exploring the influence of the Internet on the lives of indigenous and diasporic peoples, Kyra Landzelius leads a team of expert anthropologists and ethnographers who go on-site and on-line to explore how a diverse range of indigenous and transnational diasporic communities actually use the Internet. From the Taino Indians of the Caribbean, the U'wa of the Amazon rainforest, and the Tunomans and Assyrians of Iraq, to the Tingas and Zapatistas, Native on the Net is a lively and intriguing exploration of how new technologies have enabled these previously isolated peoples to reach new levels of communication and community: creating new communities online, confronting global corporations, or even challenging their own native traditions. Featuring case studies ranging from the Artic to the Australian outback, this book addresses important recurrent themes, such as the relationship between identity and place, community, traditional cultures and the nature of the 'indigenous'. Native on the Net is a unique contribut...

  4. Risk classification and uncertainty propagation for virtual water distribution systems

    International Nuclear Information System (INIS)

    Torres, Jacob M.; Brumbelow, Kelly; Guikema, Seth D.

    2009-01-01

    While the secrecy of real water distribution system data is crucial, it poses difficulty for research as results cannot be publicized. This data includes topological layouts of pipe networks, pump operation schedules, and water demands. Therefore, a library of virtual water distribution systems can be an important research tool for comparative development of analytical methods. A virtual city, 'Micropolis', has been developed, including a comprehensive water distribution system, as a first entry into such a library. This virtual city of 5000 residents is fully described in both geographic information systems (GIS) and EPANet hydraulic model frameworks. A risk classification scheme and Monte Carlo analysis are employed for an attempted water supply contamination attack. Model inputs to be considered include uncertainties in: daily water demand, seasonal demand, initial storage tank levels, the time of day a contamination event is initiated, duration of contamination event, and contaminant quantity. Findings show that reasonable uncertainties in model inputs produce high variability in exposure levels. It is also shown that exposure level distributions experience noticeable sensitivities to population clusters within the contaminant spread area. High uncertainties in exposure patterns lead to greater resources needed for more effective mitigation strategies.

  5. From water to energy. The virtual water content and water footprint of biofuel consumption in Spain

    International Nuclear Information System (INIS)

    Elena, Galan-del-Castillo; Esther, Velazquez

    2010-01-01

    Energy diversification and the use of renewable energy sources are key points in the European energy strategy. Biofuels are the most popular renewable resource option for the transport sector, and the European Union has established objectives that the Member States must adopt and implement. However, biofuel production at such a scale requires a considerable amount of water resources, and this water-energy nexus is rarely taken into account. This paper shows the strong nexus between water and energy in biofuel production and estimates the virtual water (VW) content and the water footprint (WF) from the raw material production that will be needed to reach the Spanish targets for biofuel consumption by 2010. The results show how the impact of such targets on the global and local water situation could be reduced through virtual water imports and, at the same time, how these imports could increase Spain's water and energy dependence. Hence, in order to manage water from an integral perspective of the territory, the inclusion of biofuel consumption objectives should go hand in hand with measures to reduce the demand of energy in the transport sector. (author)

  6. From water to energy. The virtual water content and water footprint of biofuel consumption in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Elena, Galan-del-Castillo [Universitat Autonoma de Barcelona (Spain); Esther, Velazquez [Pablo de Olavide University, Department of Economics, Crta. Utrera, Km.1, 41013 Seville (Spain)

    2010-03-15

    Energy diversification and the use of renewable energy sources are key points in the European energy strategy. Biofuels are the most popular renewable resource option for the transport sector, and the European Union has established objectives that the Member States must adopt and implement. However, biofuel production at such a scale requires a considerable amount of water resources, and this water-energy nexus is rarely taken into account. This paper shows the strong nexus between water and energy in biofuel production and estimates the virtual water (VW) content and the water footprint (WF) from the raw material production that will be needed to reach the Spanish targets for biofuel consumption by 2010. The results show how the impact of such targets on the global and local water situation could be reduced through virtual water imports and, at the same time, how these imports could increase Spain's water and energy dependence. Hence, in order to manage water from an integral perspective of the territory, the inclusion of biofuel consumption objectives should go hand in hand with measures to reduce the demand of energy in the transport sector. (author)

  7. From water to energy: The virtual water content and water footprint of biofuel consumption in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Galan-del-Castillo, Elena [Universitat Autonoma de Barcelona (Spain); Velazquez, Esther, E-mail: evelalo@upo.e [Pablo de Olavide University, Department of Economics, Crta. Utrera, Km.1, 41013 Seville (Spain)

    2010-03-15

    Energy diversification and the use of renewable energy sources are key points in the European energy strategy. Biofuels are the most popular renewable resource option for the transport sector, and the European Union has established objectives that the Member States must adopt and implement. However, biofuel production at such a scale requires a considerable amount of water resources, and this water-energy nexus is rarely taken into account. This paper shows the strong nexus between water and energy in biofuel production and estimates the virtual water (VW) content and the water footprint (WF) from the raw material production that will be needed to reach the Spanish targets for biofuel consumption by 2010. The results show how the impact of such targets on the global and local water situation could be reduced through virtual water imports and, at the same time, how these imports could increase Spain's water and energy dependence. Hence, in order to manage water from an integral perspective of the territory, the inclusion of biofuel consumption objectives should go hand in hand with measures to reduce the demand of energy in the transport sector.

  8. Warmer temperatures reduce net carbon uptake, but not water use, in a mature southern Appalachian forest

    Science.gov (United States)

    Increasing air temperature is expected to extend growing season length in temperate, broadleaf forests, leading to potential increases in evapotranspiration and net carbon uptake. However, other key processes affecting water and carbon cycles are also highly temperature-dependent...

  9. Ecological network analysis on global virtual water trade.

    Science.gov (United States)

    Yang, Zhifeng; Mao, Xufeng; Zhao, Xu; Chen, Bin

    2012-02-07

    Global water interdependencies are likely to increase with growing virtual water trade. To address the issues of the indirect effects of water trade through the global economic circulation, we use ecological network analysis (ENA) to shed insight into the complicated system interactions. A global model of virtual water flow among agriculture and livestock production trade in 1995-1999 is also built as the basis for network analysis. Control analysis is used to identify the quantitative control or dependency relations. The utility analysis provides more indicators for describing the mutual relationship between two regions/countries by imitating the interactions in the ecosystem and distinguishes the beneficiary and the contributor of virtual water trade system. Results show control and utility relations can well depict the mutual relation in trade system, and direct observable relations differ from integral ones with indirect interactions considered. This paper offers a new way to depict the interrelations between trade components and can serve as a meaningful start as we continue to use ENA in providing more valuable implications for freshwater study on a global scale.

  10. Efficiency, Equity and Effect: Virtual Water Consumption Characters and Sustainable Consumption on Diet

    OpenAIRE

    Shang Hai-Yang

    2015-01-01

    The scarcity of water is the key factor which restricted the growth of social-economy. The virtual water theory provides a new way to solve the problem of water scarcity. In this thesis, we have calculated the virtual water consumption of each household grouped by income in the cities of Gansu in 1992-2005 after introduced the virtual water theory and calculations briefly. Then we advanced the indicator of virtual water per unit of consumption expenditure to analyze the efficiency of virtual ...

  11. Virtual water trade patterns in relation to environmental and socioeconomic factors : A case study for Tunisia

    NARCIS (Netherlands)

    Chouchane, Hatem; Krol, Martinus S.; Hoekstra, Arjen Y.

    2018-01-01

    Growing water demands put increasing pressure on local water resources, especially in water-short countries. Virtual water trade can play a key role in filling the gap between local demand and supply of water-intensive commodities. This study aims to analyse the dynamics in virtual water trade of

  12. Impacts of changing cropping pattern on virtual water flows related to crops transfer: a case study for the Hetao irrigation district, China.

    Science.gov (United States)

    Liu, Jing; Wu, Pute; Wang, Yubao; Zhao, Xining; Sun, Shikun; Cao, Xinchun

    2014-11-01

    Analysis of cropping patterns is a prerequisite for their optimisation, and evaluation of virtual water flows could shed new light on water resources management. This study is intended to explore the effects of cropping pattern changes between 1960 and 2008 on virtual water flows related to crops transfer in the Hetao irrigation district, China. (1) The sown area of crops increased at an average rate of 3.57 × 10(3) ha year(-1) while the proportion of sown grain crops decreased from 92.83% in the 1960s to 50.22% in the 2000s. (2) Virtual water content decreased during the study period while net virtual water exports increased since the 1980s. (3) Assuming that the cropping pattern was constant and was equal to the average 1960s value, accumulated net virtual water export in 1980-2008 would have been 4.76 × 10(9) m(3) greater than that in the actual cropping pattern scenario. Cropping pattern changes in the Hetao irrigation district could not only be seen as resulting from the pursuit for higher economic returns, but also as a feedback response to limited water resources. A systematic framework is still needed for future cropping pattern planning by taking food security, continued agricultural expansion and other constraints into consideration. © 2014 Society of Chemical Industry.

  13. Uncovering regional disparity of China's water footprint and inter-provincial virtual water flows.

    Science.gov (United States)

    Dong, Huijuan; Geng, Yong; Fujita, Tsuyoshi; Fujii, Minoru; Hao, Dong; Yu, Xiaoman

    2014-12-01

    With rapid economic development in China, water crisis is becoming serious and may impede future sustainable development. The uneven distribution of water resources further aggravates such a problem. Under such a circumstance, the concepts of water footprint and virtual water have been proposed in order to respond water scarcity problems. This paper focuses on studying provincial disparity of China's water footprints and inter-provincial virtual water trade flows by adopting inter-regional input-output (IRIO) method. The results show that fast developing areas with larger economic scales such as Guangdong, Jiangsu, Shandong, Zhejiang, Shanghai and Xinjiang had the largest water footprints. The most developed and water scarce areas such as Shanghai, Beijing, Tianjin and Shandong intended to import virtual water, a rational choice for mitigating their water crisis. Xinjiang, Jiangsu, Heilongjiang, Inner Mongolia, Guangxi and Hunan, had the largest per GDP water intensities and were the main water import regions. Another key finding is that agriculture water footprint was the main part in water footprint composition and water export trade. On the basis of these findings, policy implications on agriculture geographical dispersion, consumption behavior changes, trade structure adjustment and water use efficiency improvement are further discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Consumptive water footprint and virtual water trade scenarios for China - With a focus on crop production, consumption and trade.

    Science.gov (United States)

    Zhuo, La; Mekonnen, Mesfin M; Hoekstra, Arjen Y

    2016-09-01

    The study assesses green and blue water footprints (WFs) and virtual water (VW) trade in China under alternative scenarios for 2030 and 2050, with a focus on crop production, consumption and trade. We consider five driving factors of change: climate, harvested crop area, technology, diet, and population. Four scenarios (S1-S4) are constructed by making use of three of IPCC's shared socio-economic pathways (SSP1-SSP3) and two of IPCC's representative concentration pathways (RCP 2.6 and RCP 8.5) and taking 2005 as the baseline year. Results show that, across the four scenarios and for most crops, the green and blue WFs per tonne will decrease compared to the baseline year, due to the projected crop yield increase, which is driven by the higher precipitation and CO2 concentration under the two RCPs and the foreseen uptake of better technology. The WF per capita related to food consumption decreases in all scenarios. Changing to the less-meat diet can generate a reduction in the WF of food consumption of 44% by 2050. In all scenarios, as a result of the projected increase in crop yields and thus overall growth in crop production, China will reverse its role from net VW importer to net VW exporter. However, China will remain a big net VW importer related to soybean, which accounts for 5% of the WF of Chinese food consumption (in S1) by 2050. All scenarios show that China could attain a high degree of food self-sufficiency while simultaneously reducing water consumption in agriculture. However, the premise of realizing the presented scenarios is smart water and cropland management, effective and coherent policies on water, agriculture and infrastructure, and, as in scenario S1, a shift to a diet containing less meat. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Analysis of virtual water flows associated with the trade of maize in the SADC region: importance of scale

    Directory of Open Access Journals (Sweden)

    J. M. Dabrowski

    2009-10-01

    Full Text Available The concept of virtual water encourages a country to view agricultural crops in terms of the amount of water required to produce those crops, with a view to implementing trading policies that promote the saving of scarce water resources. Recently, increased attention has focussed on partitioning the virtual water content of crops into green and blue water (derived from rainfall and irrigation, respectively as the latter has higher opportunity costs associated with its use and therefore impacts directly on scarcity. Maize is the most important crop traded within the SADC region. South Africa is the largest producer and exporter of maize, with the majority of its exports destined for other SADC countries. In comparison to other SADC countries, South Africa produces maize relatively efficiently, with a low virtual water content and a high green (868 m3 t−1 to blue (117 m3 t−1 water ratio. The blue water content is however higher than for maize produced in all other SADC countries, with the exception of Namibia (211 m3 t−1. Current trade patterns therefore result in a net expenditure of blue water (66×106 m3, almost all of which is exported by South Africa (65×106 m3. South Africa is one of the most water scarce countries in the region and analysis of virtual water flows indicates that current SADC maize trading patterns are influenced by national productivity as opposed to water scarcity. The virtual water content of maize was estimated for each of South Africa's nineteen Water Management Area's (WMA and used as a proxy to represent water use efficiency for maize production. The virtual water content varied widely across all of the WMAs, ranging from 360 m3 t−1 in the Ustutu Mhlatuze to 1000 m3 t−1 in the Limpopo. A comparison of the virtual water content and production of maize

  16. Mineralizing urban net-zero water treatment: Field experience for energy-positive water management.

    Science.gov (United States)

    Wu, Tingting; Englehardt, James D

    2016-12-01

    An urban net-zero water treatment system, designed for energy-positive water management, 100% recycle of comingled black/grey water to drinking water standards, and mineralization of hormones and other organics, without production of concentrate, was constructed and operated for two years, serving an occupied four-bedroom, four-bath university residence hall apartment. The system comprised septic tank, denitrifying membrane bioreactor (MBR), iron-mediated aeration (IMA) reactor, vacuum ultrafilter, and peroxone or UV/H 2 O 2 advanced oxidation, with 14% rainwater make-up and concomitant discharge of 14% of treated water (ultimately for reuse in irrigation). Chemical oxygen demand was reduced to 12.9 ± 3.7 mg/L by MBR and further decreased to below the detection limit (treatment. The process produced a mineral water meeting 115 of 115 Florida drinking water standards that, after 10 months of recycle operation with ∼14% rainwater make-up, had a total dissolved solids of ∼500 mg/L, pH 7.8 ± 0.4, turbidity 0.12 ± 0.06 NTU, and NO 3 -N concentration 3.0 ± 1.0 mg/L. None of 97 hormones, personal care products, and pharmaceuticals analyzed were detected in the product water. For a typical single-home system with full occupancy, sludge pumping is projected on a 12-24 month cycle. Operational aspects, including disinfection requirements, pH evolution through the process, mineral control, advanced oxidation by-products, and applicability of point-of-use filters, are discussed. A distributed, peroxone-based NZW management system is projected to save more energy than is consumed in treatment, due largely to retention of wastewater thermal energy. Recommendations regarding design and operation are offered. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Today's virtual water consumption and trade under future water scarcity

    International Nuclear Information System (INIS)

    Orlowsky, B; Gudmundsson, L; Seneviratne, Sonia I; Hoekstra, A Y

    2014-01-01

    The populations of most nations consume products of both domestic and foreign origin, importing together with the products the water which is expended abroad for their production (termed ‘virtual water’). Therefore, any investigation of the sustainability of present-day water consumption under future climate change needs to consider the effects of potentially reduced water availability both on domestic water resources and on the trades of virtual water. Here we use combinations of Global Climate and Global Impact Models from the ISI–MIP ensemble to derive patterns of future water availability under the RCP2.6 and RCP8.5 greenhouse gas (GHG) concentrations scenarios. We assess the effects of reduced water availability in these scenarios on national water consumptions and virtual water trades through a simple accounting scheme based on the water footprint concept. We thereby identify countries where the water footprint within the country area is reduced due to a reduced within-area water availability, most prominently in the Mediterranean and some African countries. National water consumption in countries such as Russia, which are non-water scarce by themselves, can be affected through reduced imports from water scarce countries. We find overall stronger effects of the higher GHG concentrations scenario, although the model range of climate projections for single GHG concentrations scenarios is in itself larger than the differences induced by the GHG concentrations scenarios. Our results highlight that, for both investigated GHG concentration scenarios, the current water consumption and virtual water trades cannot be sustained into the future due to the projected patterns of reduced water availability. (letter)

  18. Can net photosynthesis and water relations provide a clue on the ...

    African Journals Online (AJOL)

    Net photosynthesis, sap flow density (SFD) and water use efficiency (WUE) were measured in a Quercus suber forest in north Tunisia in an attempt to explain the forest decline. In general, sap flow was positively related to light intensity and water loss, indicating that high light intensities can increase the SFD up to the ...

  19. Urban water metabolism efficiency assessment: integrated analysis of available and virtual water.

    Science.gov (United States)

    Huang, Chu-Long; Vause, Jonathan; Ma, Hwong-Wen; Yu, Chang-Ping

    2013-05-01

    Resolving the complex environmental problems of water pollution and shortage which occur during urbanization requires the systematic assessment of urban water metabolism efficiency (WME). While previous research has tended to focus on either available or virtual water metabolism, here we argue that the systematic problems arising during urbanization require an integrated assessment of available and virtual WME, using an indicator system based on material flow analysis (MFA) results. Future research should focus on the following areas: 1) analysis of available and virtual water flow patterns and processes through urban districts in different urbanization phases in years with varying amounts of rainfall, and their environmental effects; 2) based on the optimization of social, economic and environmental benefits, establishment of an indicator system for urban WME assessment using MFA results; 3) integrated assessment of available and virtual WME in districts with different urbanization levels, to facilitate study of the interactions between the natural and social water cycles; 4) analysis of mechanisms driving differences in WME between districts with different urbanization levels, and the selection of dominant social and economic driving indicators, especially those impacting water resource consumption. Combinations of these driving indicators could then be used to design efficient water resource metabolism solutions, and integrated management policies for reduced water consumption. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. UV sensitivity of planktonic net community production in ocean surface waters

    OpenAIRE

    Regaudie de Gioux, Aurore; Agustí, Susana; Duarte, Carlos M.

    2014-01-01

    The net plankton community metabolism of oceanic surface waters is particularly important as it more directly affects the partial pressure of CO2 in surface waters and thus the air-sea fluxes of CO2. Plankton communities in surface waters are exposed to high irradiance that includes significant ultraviolet blue (UVB, 280-315 nm) radiation. UVB radiation affects both photosynthetic and respiration rates, increase plankton mortality rates, and other metabolic and chemical processes. Here we tes...

  1. Irrigation Alternatives to Meet Army Net Zero Water Goals

    Science.gov (United States)

    2012-05-01

    Use of mulches  Appropriate maintenance BUILDING STRONG® Soil Additives/Amendments  Maximize soil moisture retention ► Compost to improve water...holding capacity ►Polyacrylamides to prolong soil moisture release ► Ideal soil texture (mix of clay, silt, and sand) maintained to adequate depths...BUILDING STRONG® Mulches  Organic ► Compost ►Shredded barks and other landscape wastes  Inorganic ►Gravel ►Rock ►Crumb rubber ►Fabrics and

  2. Virtual Water and Water Footprints: Overreaching Into the Discourse on Sustainability, Efficiency, and Equity

    Directory of Open Access Journals (Sweden)

    Dennis Wichelns

    2015-10-01

    Full Text Available The notions of virtual water and water footprints were introduced originally to bring attention to the large amounts of water required to produce crops and livestock. Recently, several authors have begun applying those notions in efforts to describe efficiency, equity, and the sustainability of resources and production activities. In this paper, I describe why the notions of virtual water and water footprints are not appropriate for analysing issues pertaining to those topics. Both notions lack a supporting conceptual framework and they contain too little information to enhance understanding of important policy issues. Neither notion accounts for the opportunity cost or scarcity value of water in any setting, or the impacts of water availability and use on livelihoods. In addition, countries trade in goods and services – not in crop and livestock water requirements. Thus, the notions of virtual water and water footprints cannot provide helpful insight regarding the sustainability of water use, economic efficiency, or social equity. Gaining such insight requires the application of legitimate conceptual frameworks, representing a broad range of perspectives from the physical and social sciences, with due consideration of dynamics, uncertainty, and the impacts of policy choices on livelihoods and natural resources.

  3. Controls of the U.S. Virtual Water Transfer Network

    Science.gov (United States)

    Garcia, S.; Mejia, A.

    2017-12-01

    A complex interplay of human and natural factors shape the economic geography of the U.S., operating through socioeconomic forces that drive the consumption, production, and exchange of commodities. The virtual water content of a commodity represents the water embedded in its production. This work investigates the controls of national bilateral transfers of the virtual water transfer network (VWTN), through a gravity-type spatial interaction model. We use a probabilistic model to predict the binary network and investigate whether the gravity model can explain the topological properties of the empirical weighted network. In general, the gravity model relates transfer flows to the mass of the trading regions and their geographical distance. We hypothesize that properties of the nodes such as population, employment, and availability of land, together with the Euclidean distance between two trading regions, capture the main drivers of the national VWTN. The results from the model are then compared to the empirical weighted network to verify its ability to model the structure of this self-organized system. The proposed empirical model provides insight into the processes that underlie the formation of the VWTN. It can be a promising tool to study how flows are affected by changes in the generating conditions due to shocks and/or stresses.

  4. Virtual water trade of agri-food products: Evidence from italian-chinese relations.

    Science.gov (United States)

    Lamastra, Lucrezia; Miglietta, Pier Paolo; Toma, Pierluigi; De Leo, Federica; Massari, Stefania

    2017-12-01

    At global scale, the majority of world water withdrawal is for the agricultural sector, with differences among countries depending on the relevance of agri-food sector in the economy. Virtual water and water footprint could be useful to express the impact on the water resources of each production process and good with the objective to lead to a sustainable use of water at a global level. International trade could be connected to the virtual water flows, in fact through commodities importation, water poor countries can save their own water resources. The present paper focuses on the bilateral virtual water flows connected to the top ten agri-food products traded between Italy and China. Comparing the virtual water flow related to the top 10 agri-food products, the virtual water flow from Italy to China is bigger than the water flow in the opposite direction. Moreover, the composition of virtual water flows is different; Italy imports significant amounts of grey water from China, depending on the different environmental strategies adopted by the two selected countries. This difference could be also related to the fact that traded commodities are very different; the 91% of virtual water imported by Italy is connected to crops products, while the 95% of virtual water imported by China is related to the animal products. Considering national water saving and global water saving, appears that Italy imports virtual water from China while China exerts pressure on its water resources to supply the exports to Italy. This result at global scale implies a global water loss of 129.29millionm3 because, in general, the agri-food products are traded from the area with lower water productivity to the area with the higher water productivity. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. UV sensitivity of planktonic net community production in ocean surface waters

    Science.gov (United States)

    Regaudie-de-Gioux, Aurore; Agustí, Susana; Duarte, Carlos M.

    2014-05-01

    The net plankton community metabolism of oceanic surface waters is particularly important as it more directly affects the partial pressure of CO2 in surface waters and thus the air-sea fluxes of CO2. Plankton communities in surface waters are exposed to high irradiance that includes significant ultraviolet blue (UVB, 280-315 nm) radiation. UVB radiation affects both photosynthetic and respiration rates, increase plankton mortality rates, and other metabolic and chemical processes. Here we test the sensitivity of net community production (NCP) to UVB of planktonic communities in surface waters across contrasting regions of the ocean. We observed here that UVB radiation affects net plankton community production at the ocean surface, imposing a shift in NCP by, on average, 50% relative to the values measured when excluding partly UVB. Our results show that under full solar radiation, the metabolic balance shows the prevalence of net heterotrophic community production. The demonstration of an important effect of UVB radiation on NCP in surface waters presented here is of particular relevance in relation to the increased UVB radiation derived from the erosion of the stratospheric ozone layer. Our results encourage design future research to further our understanding of UVB effects on the metabolic balance of plankton communities.

  6. Spatial organization and drivers of the virtual water trade: a community-structure analysis

    International Nuclear Information System (INIS)

    D’Odorico, Paolo; Carr, Joel; Laio, Francesco; Ridolfi, Luca

    2012-01-01

    The trade of agricultural commodities can be associated with a virtual transfer of the local freshwater resources used for the production of these goods. Thus, trade of food products virtually transfers large amounts of water from areas of food production to far consumption regions, a process termed the ‘globalization of water’. We consider the (time-varying) community structure of the virtual water network for the years 1986–2008. The communities are groups of countries with dense internal connections, while the connections are sparser among different communities. Between 1986 and 2008, the ratio between virtual water flows within communities and the total global trade of virtual water has continuously increased, indicating the existence of well defined clusters of virtual water transfers. In some cases (e.g. Central and North America and Europe in recent years) the virtual water communities correspond to geographically coherent regions, suggesting the occurrence of an ongoing process of regionalization of water resources. However, most communities also include countries located on different ‘sides’ of the world. As such, geographic proximity only partly explains the community structure of virtual water trade. Similarly, the global distribution of people and wealth, whose effect on the virtual water trade is expressed through simple ‘gravity models’, is unable to explain the strength of virtual water communities observed in the past few decades. A gravity model based on the availability of and demand for virtual water in different countries has higher explanatory power, but the drivers of the virtual water fluxes are yet to be adequately identified. (letter)

  7. The Water Suitcase of Migrants: Assessing Virtual Water Fluxes Associated to Human Migration.

    Science.gov (United States)

    Metulini, Rodolfo; Tamea, Stefania; Laio, Francesco; Riccaboni, Massimo

    2016-01-01

    Disentangling the relations between human migrations and water resources is relevant for food security and trade policy in water-scarce countries. It is commonly believed that human migrations are beneficial to the water endowments of origin countries for reducing the pressure on local resources. We show here that such belief is over-simplistic. We reframe the problem by considering the international food trade and the corresponding virtual water fluxes, which quantify the water used for the production of traded agricultural commodities. By means of robust analytical tools, we show that migrants strengthen the commercial links between countries, triggering trade fluxes caused by food consumption habits persisting after migration. Thus migrants significantly increase the virtual water fluxes and the use of water in the countries of origin. The flux ascribable to each migrant, i.e. the "water suitcase", is found to have increased from 321 m3/y in 1990 to 1367 m3/y in 2010. A comparison with the water footprint of individuals shows that where the water suitcase exceeds the water footprint of inhabitants, migrations turn out to be detrimental to the water endowments of origin countries, challenging the common perception that migrations tend to relieve the pressure on the local (water) resources of origin countries.

  8. The phase diagram of water at negative pressures: virtual ices.

    Science.gov (United States)

    Conde, M M; Vega, C; Tribello, G A; Slater, B

    2009-07-21

    The phase diagram of water at negative pressures as obtained from computer simulations for two models of water, TIP4P/2005 and TIP5P is presented. Several solid structures with lower densities than ice Ih, so-called virtual ices, were considered as possible candidates to occupy the negative pressure region of the phase diagram of water. In particular the empty hydrate structures sI, sII, and sH and another, recently proposed, low-density ice structure. The relative stabilities of these structures at 0 K was determined using empirical water potentials and density functional theory calculations. By performing free energy calculations and Gibbs-Duhem integration the phase diagram of TIP4P/2005 was determined at negative pressures. The empty hydrates sII and sH appear to be the stable solid phases of water at negative pressures. The phase boundary between ice Ih and sII clathrate occurs at moderate negative pressures, while at large negative pressures sH becomes the most stable phase. This behavior is in reasonable agreement with what is observed in density functional theory calculations.

  9. Effects of virtual water flow on regional water resources stress: A case study of grain in China.

    Science.gov (United States)

    Sun, Shikun; Wang, Yubao; Engel, Bernie A; Wu, Pute

    2016-04-15

    Scarcity of water resources is one of the major challenges in the world, particularly for the main water consumer, agriculture. Virtual water flow (VWF) promotes water redistribution geographically and provides a new solution for resolving regional water shortage and improving water use efficiency in the world. Virtual water transfer among regions will have a significant influence on the water systems in both grain export and import regions. In order to assess the impacts of VWF related grain transfer on regional water resources conditions, the study takes mainland China as study area for a comprehensive evaluation of virtual water flow on regional water resources stress. Results show that Northeast China and Huang-Huai-Hai region are the major grain production regions as well as the major virtual water export regions. National water savings related to grain VWF was about 58Gm(3), with 48Gm(3) blue water and 10Gm(3) green water. VWF changes the original water distribution and has a significant effect on water resources in both virtual water import and export regions. Grain VWF significantly increased water stress in grain export regions and alleviated water stress in grain import regions. Water stress index (WSI) of Heilongjiang and Inner Mongolia has been increased by 138% and 129% due to grain export. Stress from water shortages is generally severe in export regions, and issues with the sustainability of grain production and VWF pattern are worthy of further exploration. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Virtual Mission First Results Supporting the WATER HM Satellite Concept

    Science.gov (United States)

    Alsdorf, D.; Andreadis, K.; Lettenmaier, D.; Moller, D.; Rodriguez, E.; Bates, P.; Mognard, N.; Participants, W.

    2007-12-01

    Surface fresh water is essential for life, yet we have surprisingly poor knowledge of its variability in space and time. Similarly, ocean circulation and ocean-atmosphere interactions fundamentally drive weather and climate variability, yet the global ocean current and eddy field (e.g., the Gulf Stream) that affects ocean circulation is poorly known. The Water And Terrestrial Elevation Recovery Hydrosphere Mapper satellite mission concept (WATER HM or SWOT per the NRC Decadal Survey) is a swath-based interferometric-altimeter designed to acquire elevations of ocean and terrestrial water surfaces at unprecedented spatial and temporal resolutions. WATER HM will have tremendous implications for estimation of the global water cycle, water management, ocean and coastal circulation, and assessment of many water-related impacts from climate change (e.g., sea level rise, carbon evasion, etc.). We describe a hydrological "virtual mission" (VM) for WATER HM which consists of: (a) A hydrodynamic-instrument simulation model that maps variations in water levels along river channels and across floodplains. These are then assimilated to estimate discharge and to determine trade-offs between resolutions and mission costs. (b) Measurements from satellites to determine feasibility of existing platforms for measuring storage changes and estimating discharge. First results demonstrate that: (1) Ensemble Kalman filtering of VM simulations recover water depth and discharge, reducing the discharge RMSE from 23.2% to 10.0% over an 84- day simulation period, relative to a simulation without assimilation. The filter also shows that an 8-day overpass frequency produces discharge relative errors of 10.0%, while 16-day and 32-day frequencies result in errors of 12.1% and 16.9%, respectively. (2) SRTM measurements of water surfaces along the Mississippi, Missouri, Ohio, and Amazon rivers, as well as smaller tributaries, show height standard deviations of 5 meters or greater (SRTM is the

  11. TIGER-NET – enabling an Earth Observation capacity for Integrated Water Resource Management in Africa

    DEFF Research Database (Denmark)

    Walli, A.; Tøttrup, C.; Naeimi, V.

    As part of the TIGER initiative [1] the TIGER-NET project aims to support the assessment and monitoring of water resources from watershed to transboundary basin level delivering indispensable information for Integrated Water Resource Management in Africa through: 1. Development of an open......-source Water Observation and Information Systems (WOIS) for monitoring, assessing and inventorying water resources in a cost-effective manner; 2. Capacity building and training of African water authorities and technical centers to fully exploit the increasing observation capacity offered by current...... and upcoming generations of satellites, including the Sentinel missions. Dedicated application case studies have been developed and demonstrated covering all EO products required by and developed with the participating African water authorities for their water resource management tasks, such as water reservoir...

  12. Virtual scarce water embodied in inter-provincial electricity transmission in China

    International Nuclear Information System (INIS)

    Zhang, Chao; Zhong, Lijin; Liang, Sai; Sanders, Kelly T.; Wang, Jiao; Xu, Ming

    2017-01-01

    Highlights: • Virtual water in inter-provincial electricity transmission in China is calculated. • A Water Stress Index is used to reflect relative scarcity of water consumption. • West Inner Mongolia is the largest exporter of scarce water. • Hebei, Beijing and Shandong are the three largest receivers of scarce water. - Abstract: Intra-national electricity transmission drives virtual water transfer from electricity production regions to electricity consumption regions. In China, the water-intensive thermoelectric power industry is expanding quickly in many water-scarce energy production hubs in northern and northwestern provinces. This study constructed a node-flow model of inter-provincial electricity transmission to investigate the virtual water and scarcity-adjusted virtual water (or virtual scarce water) embodied in the electricity transmission network. It is revealed that total inter-provincial virtual water transfer embodied in electricity transmission was 623 million m"3 in 2011, equivalent to 12.7% of the national total thermoelectric water consumption. The top three largest single virtual water flows are West Inner Mongolia-to-Beijing (44 million m"3), East Inner Mongolia-to-Liaoning (39 million m"3), and Guizhou-to-Guangdong (37 million m"3). If the actual volumes of consumptive water use are translated into scarcity-adjusted water consumption based on Water Stress Index, West Inner Mongolia (81 million m"3), Shanxi (63 million m"3) and Ningxia (30 million m"3) become the top three exporters of virtual scarce water. Many ongoing long-distance electricity transmission projects in China will enlarge the scale of scarce water outflows from northwestern regions and potentially increase their water stress.

  13. Virtual water trade and country vulnerability: A network perspective

    Science.gov (United States)

    Sartori, Martina; Schiavo, Stefano

    2015-04-01

    This work investigates the relationship between countries' participation in virtual water trade and their vulnerability to external shocks from a network perspective. In particular, we investigate whether (i) possible sources of local national crises may interact with the system, propagating through the network and affecting the other countries involved; (ii) the topological characteristics of the international agricultural trade network, translated into virtual water-equivalent flows, may favor countries' vulnerability to external crises. Our work contributes to the debate on the potential merits and risks associated with openness to trade in agricultural and food products. On the one hand, trade helps to ensure that even countries with limited water (and other relevant) resources have access to sufficient food and contribute to the global saving of water. On the other hand, there are fears that openness may increase the vulnerability to external shocks and thus make countries worse off. Here we abstract from political considerations about food sovereignty and independence from imports and focus instead on investigating whether the increased participation in global trade that the world has witnessed in the last 30 years has made the system more susceptible to large shocks. Our analysis reveals that: (i) the probability of larger supply shocks has not increased over time; (ii) the topological characteristics of the VW network are not such as to favor the systemic risk associated with shock propagation; and (iii) higher-order interconnections may reveal further important information about the structure of a network. Regarding the first result, fluctuations in output volumes, among the sources of shock analyzed here, are more likely to generate some instability. The first implication is that, on one side, past national or regional economic crises were not necessarily brought about or strengthened by global trade. The second, more remarkable, implication is that, on

  14. A global sensitivity analysis of crop virtual water content

    Science.gov (United States)

    Tamea, S.; Tuninetti, M.; D'Odorico, P.; Laio, F.; Ridolfi, L.

    2015-12-01

    The concepts of virtual water and water footprint are becoming widely used in the scientific literature and they are proving their usefulness in a number of multidisciplinary contexts. With such growing interest a measure of data reliability (and uncertainty) is becoming pressing but, as of today, assessments of data sensitivity to model parameters, performed at the global scale, are not known. This contribution aims at filling this gap. Starting point of this study is the evaluation of the green and blue virtual water content (VWC) of four staple crops (i.e. wheat, rice, maize, and soybean) at a global high resolution scale. In each grid cell, the crop VWC is given by the ratio between the total crop evapotranspiration over the growing season and the crop actual yield, where evapotranspiration is determined with a detailed daily soil water balance and actual yield is estimated using country-based data, adjusted to account for spatial variability. The model provides estimates of the VWC at a 5x5 arc minutes and it improves on previous works by using the newest available data and including multi-cropping practices in the evaluation. The model is then used as the basis for a sensitivity analysis, in order to evaluate the role of model parameters in affecting the VWC and to understand how uncertainties in input data propagate and impact the VWC accounting. In each cell, small changes are exerted to one parameter at a time, and a sensitivity index is determined as the ratio between the relative change of VWC and the relative change of the input parameter with respect to its reference value. At the global scale, VWC is found to be most sensitive to the planting date, with a positive (direct) or negative (inverse) sensitivity index depending on the typical season of crop planting date. VWC is also markedly dependent on the length of the growing period, with an increase in length always producing an increase of VWC, but with higher spatial variability for rice than for

  15. Why a regional approach to postgraduate water education makes sense - the WaterNet experience in Southern Africa

    Science.gov (United States)

    Jonker, L.; van der Zaag, P.; Gumbo, B.; Rockström, J.; Love, D.; Savenije, H. H. G.

    2012-03-01

    This paper reports the experience of a regional network of academic departments involved in water education that started as a project and evolved, over a period of 12 yr, into an independent network organisation. The paper pursues three objectives. First, it argues that it makes good sense to organise postgraduate education and research on water resources on a regional scale. This is because water has a transboundary dimension that poses delicate sharing questions, an approach that promotes a common understanding of what the real water-related issues are, results in future water specialists speaking a common (water) language, enhances mutual respect, and can thus be considered an investment in future peace. Second, it presents the WaterNet experience as an example that a regional approach can work and has an impact. Third, it draws three generalised lessons from the WaterNet experience. Lesson 1: For a regional capacity building network to be effective, it must have a legitimate ownership structure and a clear mandate. Lesson 2: Organising water-related training opportunities at a regional and transboundary scale makes sense - not only because knowledge resources are scattered, but also because the topic - water - has a regional and transboundary scope. Lesson 3: Jointly developing educational programmes by sharing expertise and resources requires intense intellectual management and sufficient financial means.

  16. Virtual Crop Water Export Analysis: The Case of Greece at River Basin District Level

    Directory of Open Access Journals (Sweden)

    Nikolaos Mellios

    2018-05-01

    Full Text Available An analysis of virtual crop water export through international trade is conducted for Greece, downscaled to the River Basin District (RBD level, in order to identify critical “hotspots” of localized water shortage in the country. A computable general equilibrium model (MAGNET was used to obtain the export shares of crops and associated irrigation water was calculated for all major crops in Greece. A distinction between virtual crop water locally consumed and traded internationally was made for all Greek RBDs. Cotton was identified as a large water consumer and virtual water exporter, while GR08 and GR10 were identified as the RBDs mostly impacted. The value of virtual water exported was calculated for all crop types and fruits and vegetables were identified as the crop most beneficial, since they consume the least water for the obtained value.

  17. International Virtual Observatory System for Water Resources Information

    Science.gov (United States)

    Leinenweber, Lewis; Bermudez, Luis

    2013-04-01

    Sharing, accessing, and integrating hydrologic and climatic data have been identified as a critical need for some time. The current state of data portals, standards, technologies, activities, and expertise can be leverage to develop an initial operational capability for a virtual observatory system. This system will allow to link observations data with stream networks and models, and to solve semantic inconsistencies among communities. Prototyping a virtual observatory system is an inter-disciplinary, inter-agency and international endeavor. The Open Geospatial Consortium (OGC) within the OGC Interoperability Program provides the process and expertise to run such collaborative effort. The OGC serves as a global forum for the collaboration of developers and users of spatial data products and services, and to advance the development of international standards for geospatial interoperability. The project coordinated by OGC that is advancing an international virtual observatory system for water resources information is called Climatology-Hydrology Information Sharing Pilot, Phase 1 (CHISP-1). It includes observations and forecasts in the U.S. and Canada levering current networks and capabilities. It is designed to support the following use cases: 1) Hydrologic modeling for historical and near-future stream flow and groundwater conditions. Requires the integration of trans-boundary stream flow and groundwater well data, as well as national river networks (US NHD and Canada NHN) from multiple agencies. Emphasis will be on time series data and real-time flood monitoring. 2) Modeling and assessment of nutrient load into the lakes. Requires accessing water-quality data from multiple agencies and integrating with stream flow information for calculating loads. Emphasis on discrete sampled water quality observations, linking those to specific NHD stream reaches and catchments, and additional metadata for sampled data. The key objectives of these use cases are: 1) To link

  18. Optimal allocation of physical water resources integrated with virtual water trade in water scarce regions: A case study for Beijing, China.

    Science.gov (United States)

    Ye, Quanliang; Li, Yi; Zhuo, La; Zhang, Wenlong; Xiong, Wei; Wang, Chao; Wang, Peifang

    2018-02-01

    This study provides an innovative application of virtual water trade in the traditional allocation of physical water resources in water scarce regions. A multi-objective optimization model was developed to optimize the allocation of physical water and virtual water resources to different water users in Beijing, China, considering the trade-offs between economic benefit and environmental impacts of water consumption. Surface water, groundwater, transferred water and reclaimed water constituted the physical resource of water supply side, while virtual water flow associated with the trade of five major crops (barley, corn, rice, soy and wheat) and three livestock products (beef, pork and poultry) in agricultural sector (calculated by the trade quantities of products and their virtual water contents). Urban (daily activities and public facilities), industry, environment and agriculture (products growing) were considered in water demand side. As for the traditional allocation of physical water resources, the results showed that agriculture and urban were the two predominant water users (accounting 54% and 28%, respectively), while groundwater and surface water satisfied around 70% water demands of different users (accounting 36% and 34%, respectively). When considered the virtual water trade of eight agricultural products in water allocation procedure, the proportion of agricultural consumption decreased to 45% in total water demand, while the groundwater consumption decreased to 24% in total water supply. Virtual water trade overturned the traditional components of water supplied from different sources for agricultural consumption, and became the largest water source in Beijing. Additionally, it was also found that environmental demand took a similar percentage of water consumption in each water source. Reclaimed water was the main water source for industrial and environmental users. The results suggest that physical water resources would mainly satisfy the consumption

  19. Catch me if you can: Comparing ballast water sampling skids to traditional net sampling

    Science.gov (United States)

    Bradie, Johanna; Gianoli, Claudio; Linley, Robert Dallas; Schillak, Lothar; Schneider, Gerd; Stehouwer, Peter; Bailey, Sarah

    2018-03-01

    With the recent ratification of the International Convention for the Control and Management of Ships' Ballast Water and Sediments, 2004, it will soon be necessary to assess ships for compliance with ballast water discharge standards. Sampling skids that allow the efficient collection of ballast water samples in a compact space have been developed for this purpose. We ran 22 trials on board the RV Meteor from June 4-15, 2015 to evaluate the performance of three ballast water sampling devices (traditional plankton net, Triton sampling skid, SGS sampling skid) for three organism size classes: ≥ 50 μm, ≥ 10 μm to Natural sea water was run through the ballast water system and untreated samples were collected using paired sampling devices. Collected samples were analyzed in parallel by multiple analysts using several different analytic methods to quantify organism concentrations. To determine whether there were differences in the number of viable organisms collected across sampling devices, results were standardized and statistically treated to filter out other sources of variability, resulting in an outcome variable representing the mean difference in measurements that can be attributed to sampling devices. These results were tested for significance using pairwise Tukey contrasts. Differences in organism concentrations were found in 50% of comparisons between sampling skids and the plankton net for ≥ 50 μm, and ≥ 10 μm to < 50 μm size classes, with net samples containing either higher or lower densities. There were no differences for < 10 μm organisms. Future work will be required to explicitly examine the potential effects of flow velocity, sampling duration, sampled volume, and organism concentrations on sampling device performance.

  20. The influence of fish culture in floating net cages on microbial indicators of water quality

    Directory of Open Access Journals (Sweden)

    K. Gorlach-Lira

    Full Text Available This work was carried out to analyse the microbiological parameters of the water quality of a reservoir used for the irrigation and culture of tilapia (Oreochromis niloticus in floating net cages. The physico-chemical parameters, counts of mesophilic total aerobic bacteria, total and thermotolerant coliforms and fecal streptococci, and the presence of Escherichia coli in samples of water collected in three sites of the reservoir (pre-culture site, culture site, post-culture site were analysed. The levels of ammonia (0.047-0.059 mg/L, nitrite (0.001-0.021 mg/L and total phosphorus (0.050-0.355 mg/L in the water did not show significant differences (p > 0.05 between sampling sites. The levels of total bacteria in the water varied between 1.3 x 104 and 67.3 x 104 CFU/100 mL. The MPN values of thermotolerant coliforms (< 930 MPN/100 mL were within values recommended for water used for fish culture and/or irrigation. The presence of E. coli and fecal streptococci were verified in 48% and 56% of analysed samples, respectively. The site with floating net cages showed more samples contaminated with E. coli and fecal streptococci than other sampling points.

  1. Net carbon allocation in soybean seedlings as influenced by soil water stress at two soil temperatures

    International Nuclear Information System (INIS)

    McCoy, E.L.; Boersma, L.; Ekasingh, M.

    1990-01-01

    The influence of water stress at two soil temperatures on allocation of net photoassimilated carbon in soybean (Glycine max [L.] Merr.) was investigated using compartmental analysis. The experimental phase employed classical 14 C labeling methodology with plants equilibrated at soil water potentials of -0.04, -0.25 and -0.50 MPa; and soil temperatures of 25 and 10C. Carbon immobilization in the shoot apex generally followed leaf elongation rates with decreases in both parameters at increasing water stress at both soil temperatures. However, where moderate water stress resulted in dramatic declines in leaf elongation rates, carbon immobilization rates were sharply decreased only at severe water stress levels. Carbon immobilization was decreased in the roots and nodules of the nonwater stressed treatment by the lower soil temperature. This relation was reversed with severe water stress, and carbon immobilization in the roots and nodules was increased at the lower soil temperature. Apparently, the increased demand for growth and/or carbon storage in these tissues with increased water stress overcame the low soil temperature limitations. Both carbon pool sizes and partitioning of carbon to the sink tissues increased with moderate water stress at 25C soil temperature. Increased pool sizes were consistent with whole plant osmotic adjustment at moderate water stress. Increased partitioning to the sinks was consistent with carbon translocation processes being less severely influenced by water stress than is photosynthesis

  2. Net Zero Fort Carson: Integrating Energy, Water, and Waste Strategies to Lower the Environmental Impact of a Military Base

    Science.gov (United States)

    Military bases resemble small cities and face similar sustainability challenges. As pilot studies in the U.S. Army Net Zero program, 17 locations are moving to 100% renewable energy, zero depletion of water resources, and/or zero waste to landfill by 2020. Some bases target net z...

  3. Water consumption in artificial desert oasis based on net primary productivity

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Analysis of the water consumption is the basis for water allocation in oasis. However, the method of estimating oasis water consumption remains a great challenge. Based on net primary productivity (NPP) and the transpiration coefficient, a vegetation water consumption model was developed to estimate the water consumption in desert oasis in ERDAS environment. Our results demonstrated that the ecosystem in the middle reaches of the Heihe oasis consumed water of 18.41×108-21.9×108 m3 for irrigation. Without taking precipitation into account, the water consumption in farmland accounted for 77.1%-77.8% (or about 13.97×108-16.84×108 m3) of the oasis vegetation water consumption and in the farmland protection system accounting for 22%. The growing period precipitation in desert environments is about 7.02×108 m3, and the total annual precipitation is about 8.29×108 m3. The modeled water consumption of desert vegetation, however, is about 4.57×108 m3, equivalent to only 65% of the growing period precipitation or 55% of the total annual precipitation. The modeled value equals to the cumulative precipitation of greater than 5 mm, which is defined as the effective precipitation in arid desert.

  4. Spontaneous Recovery of Human Spatial Memory in a Virtual Water Maze

    Science.gov (United States)

    Luna, David; Martínez, Héctor

    2015-01-01

    The occurrence of spontaneous recovery in human spatial memory was assessed using a virtual environment. In Experiment 1, spatial memory was established by training participants to locate a hidden platform in a virtual water maze using a set of four distal landmarks. In Experiment 2, after learning about the location of a hidden platform, the…

  5. Analysis of intra-country virtual water trade strategy to alleviate water scarcity in Iran

    Science.gov (United States)

    Faramarzi, M.; Yang, H.; Mousavi, J.; Schulin, R.; Binder, C. R.; Abbaspour, K. C.

    2010-08-01

    Increasing water scarcity has posed a major constraint to sustain food production in many parts of the world. To study the situation at the regional level, we took Iran as an example and analyzed how an intra-country "virtual water trade strategy" (VWTS) may help improve cereal production as well as alleviate the water scarcity problem. This strategy calls, in part, for the adjustment of the structure of cropping pattern (ASCP) and interregional food trade where crop yield and crop water productivity as well as local economic and social conditions are taken into account. We constructed a systematic framework to assess ASCP at the provincial level under various driving forces and constraints. A mixed-integer, multi-objective, linear optimization model was developed and solved by linear programming. Data from 1990-2004 were used to account for yearly fluctuations of water availability and food production. Five scenarios were designed aimed at maximizing the national cereal production while meeting certain levels of wheat self-sufficiency under various water and land constraints in individual provinces. The results show that under the baseline scenario, which assumes a continuation of the existing water use and food policy at the national level, some ASCP scenarios could produce more wheat with less water. Based on different scenarios in ASCP, we calculated that 31% to 100% of the total wheat shortage in the deficit provinces could be supplied by the wheat surplus provinces. As a result, wheat deficit provinces would receive 3.5 billion m3 to 5.5 billion m3 of virtual water by importing wheat from surplus provinces.

  6. Well-to-Wheels Water Consumption: Tracking the Virtual Flow of Water into Transportation

    Science.gov (United States)

    Lampert, D. J.; Elgowainy, A.; Hao, C.

    2015-12-01

    Water and energy resources are fundamental to life on Earth and essential for the production of consumer goods and services in the economy. Energy and water resources are heavily interdependent—energy production consumes water, while water treatment and distribution consume energy. One example of this so-called energy-water nexus is the consumption of water associated with the production of transportation fuels. The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model is an analytical tool that can be used to compare the environmental impacts of different transportation fuels on a consistent basis. In this presentation, the expansion of GREET to perform life cycle water accounting or the "virtual flow" of water into transportation and other energy sectors and the associated implications will be discussed. The results indicate that increased usage of alternative fuels may increase freshwater resource consumption. The increased water consumption must be weighed against the benefits of decreased greenhouse gas and fossil energy consumption. Our analysis highlights the importance of regionality, co-product allocation, and consistent system boundaries when comparing the water intensity of alternative transportation fuel production pathways such as ethanol, biodiesel, compressed natural gas, hydrogen, and electricity with conventional petroleum-based fuels such as diesel and gasoline.

  7. Historical development of crop-related water footprints and inter-regional virtual water flows within China

    Science.gov (United States)

    Zhuo, La; Mekonnen, Mesfin M.; Hoekstra, Arjen Y.

    2015-04-01

    China is facing water-related challenges, including an uneven distribution of water resources, both temporally and spatially, and an increasing competition over the limited water resources among different sectors. This issue has been widely researched and was finally included into the National Plan 2011 (the 2011 No. 1 Document by the State Council of China). However, there is still lack of information on how population growth and rapid urbanization have affected the water resources in China over the last decades. The current study aims at investigating (i) the intra-annual variation of green and blue water footprints (WFs) of crop production in China over the period 1978-2009 at a spatial resolution of 5 by 5 arc-minute; (ii) the yearly virtual water (VW) balances of 31 provinces within China, related water savings for the country, as well as the VW flows among eight economic regions resulting from inter-regional crop trade over the same period; and (iii) the development of the WF related to crop consumption by Chinese consumers. Results show that, over the period 1978-2009, the total WF related to crop production within China increased by only 4%), but regional changes were significant. From the 1980s to the 2000s, the shift of the cropping centre from the South to the North resulted in an increase of about 16% in the blue WF and 19% in the green WF in the North and a reduction of the blue and green WF in the South by 11% and 3%, respectively. China as a whole was a net virtual water importer related to crop trade, thus saving domestic water resources. China's inter-regional crop trade generated a blue water 'loss' annually by transferring crops from provinces with relatively low crop water productivity to provinces with relatively high productivity. Over the decades, the original VW flow from the South coastal region to the Northeast was reversed. Rice was the all-time dominant crop in the inter-regional VW flows (accounting for 34% in 2009), followed by wheat

  8. Contribution of virtual water to improving water security in Tunisia: a case study of wheat and olive growing farms in Zaghouan region

    OpenAIRE

    Souissi, Asma; Benalaya, Abdallah; Abdelkefi, Belhassen; Stambouli, Talel Ben Bechir; Ghezal, Lamia; Belaid, Rabeh; Naceur, Youssef; Oueslati, Marwa; Fekih, Saida; Benabdallah, Saker; Frija, Aymen

    2013-01-01

    Virtual water represents all freshwater used in the process of producing a commodity. In the case of agricultural products, many studies have focused on quantifying virtual water flows through international trade products. The concept of virtual water commercialization should be carefully studied as a potential solution for water scarcity, especially in countries facing risks of water shortage in a few years such as in Tunisia. The main idea of this paper is to optimize water u...

  9. Growing a professional network to over 3000 members in less than 4 years: evaluation of InspireNet, British Columbia's virtual nursing health services research network.

    Science.gov (United States)

    Frisch, Noreen; Atherton, Pat; Borycki, Elizabeth; Mickelson, Grace; Cordeiro, Jennifer; Novak Lauscher, Helen; Black, Agnes

    2014-02-21

    Use of Web 2.0 and social media technologies has become a new area of research among health professionals. Much of this work has focused on the use of technologies for health self-management and the ways technologies support communication between care providers and consumers. This paper addresses a new use of technology in providing a platform for health professionals to support professional development, increase knowledge utilization, and promote formal/informal professional communication. Specifically, we report on factors necessary to attract and sustain health professionals' use of a network designed to increase nurses' interest in and use of health services research and to support knowledge utilization activities in British Columbia, Canada. "InspireNet", a virtual professional network for health professionals, is a living laboratory permitting documentation of when and how professionals take up Web 2.0 and social media. Ongoing evaluation documents our experiences in establishing, operating, and evaluating this network. Overall evaluation methods included (1) tracking website use, (2) conducting two member surveys, and (3) soliciting member feedback through focus groups and interviews with those who participated in electronic communities of practice (eCoPs) and other stakeholders. These data have been used to learn about the types of support that seem relevant to network growth. Network growth exceeded all expectations. Members engaged with varying aspects of the network's virtual technologies, such as teams of professionals sharing a common interest, research teams conducting their work, and instructional webinars open to network members. Members used wikis, blogs, and discussion groups to support professional work, as well as a members' database with contact information and areas of interest. The database is accessed approximately 10 times per day. InspireNet public blog posts are accessed roughly 500 times each. At the time of writing, 21 research teams

  10. Urban net-zero water treatment and mineralization: experiments, modeling and design.

    Science.gov (United States)

    Englehardt, James D; Wu, Tingting; Tchobanoglous, George

    2013-09-01

    Water and wastewater treatment and conveyance account for approximately 4% of US electric consumption, with 80% used for conveyance. Net zero water (NZW) buildings would alleviate demands for a portion of this energy, for water, and for the treatment of drinking water for pesticides and toxic chemical releases in source water. However, domestic wastewater contains nitrogen loads much greater than urban/suburban ecosystems can typically absorb. The purpose of this work was to identify a first design of a denitrifying urban NZW treatment process, operating at ambient temperature and pressure and circum-neutral pH, and providing mineralization of pharmaceuticals (not easily regulated in terms of environmental half-life), based on laboratory tests and mass balance and kinetic modeling. The proposed treatment process is comprised of membrane bioreactor, iron-mediated aeration (IMA, reported previously), vacuum ultrafiltration, and peroxone advanced oxidation, with minor rainwater make-up and H2O2 disinfection residual. Similar to biological systems, minerals accumulate subject to precipitative removal by IMA, salt-free treatment, and minor dilution. Based on laboratory and modeling results, the system can produce potable water with moderate mineral content from commingled domestic wastewater and 10-20% rainwater make-up, under ambient conditions at individual buildings, while denitrifying and reducing chemical oxygen demand to below detection (<3 mg/L). While economics appear competitive, further development and study of steady-state concentrations and sludge management options are needed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Virtual water flows related to land use in an intensive agriculture in the Fergana Valley, Uzbekistan

    Science.gov (United States)

    Klipstein, A.; Schneider, K.; Breuer, L.; Frede, H. G.

    2009-04-01

    Due to low annual precipitation, agricultural production in Uzbekistan is depending on irrigation from the Syrdarya and Amudarya rivers to a great deal. One of the most important cash crops of the country is cotton. Current irrigation management leads to elevated groundwater levels, salinization of soils and to a degradation of soil and water resources. Through export of cotton and other crops, the problems related to water consumption and water management are transported beyond the producing country. The amount of water transported through production and export is referred to as virtual water. To distinguish between productive and unproductive partitioning of water flows, the terms green and blue water have been introduced. Information on virtual water flows due to crop production usually only exist on country level. To reduce uncertainties related to generalization, the effect of land management and environmental factors on the partitioning of water flows needs to be studied on smaller scales. The presented study analyzes water fluxes in an intensively used agricultural area in the Fergana Valley, Uzbekistan. The study aims to a) quantify crop specific water consumption in agricultural production under current management and b) analyze water use efficiency as subject to land use and irrigation management. Based on crop production, irrigation management and environmental conditions in the study area, virtual water flows will be calculated on the level of agricultural collectives (Water Users Associations). In a further step, the partitioning of green and blue water fluxes will be quantified. Alternative scenarios for improved water management will be analyzed in a model study.

  12. How More Data About Direct and Virtual Water Use Could Help People Understand Their Water Footprints and Save More Water

    Science.gov (United States)

    Madel, R.; Olson-Sawyer, K.; Hanlon, P.; Rabin, K.

    2017-12-01

    Attari (2014) has shown through online surveys that Americans underestimate their water use, don't know what their water footprint is and don't know how much water it takes to produce food. The more people know about their water use, the better decisions they are capable of making and the more likely they are to conserve, which is especially important during periods of water stress. To increase awareness and help people decrease their daily water use, GRACE Communications Foundation created a Water Footprint Calculator [watercalculator.org] using US-oriented data and presented in US units in both English and Spanish. The calculator is based on direct water use data as well as the water consumed to create food, consumer goods and energy (also known as virtual or indirect water use). We learned that there is a lack of comparably-scaled, consumer-level virtual water research available. The direct use data gathered for the calculator came primarily from a study of residential water use in the US by Mayer et al. (1999), who conducted surveys of households in different US cities and averaged data for both inside and outside the home. The indirect use data came from various sources including the US government (USGS, EPA, EIA, NREL, Energy Star, etc.), the Water Footprint Network and the UN FAO. Much of the indirect use data was aggregated at a national level or came from combinations of various data sets. For all users, the food category accounts for the largest part of their water footprints. Gathering data of comparable scale at a personal consumption level proved to be a challenging exercise and provided several takeaways. While there is recent residential direct water use data at a consumer level, there is a lack of data at the personal, consumer level about indirect water use in manufacturing, energy production and agriculture. Because of this, we had to use national averages and generalized calculations. The resulting tool gives people a sense of the impacts of

  13. Fat ViP MRI: Virtual Phantom Magnetic Resonance Imaging of water-fat systems.

    Science.gov (United States)

    Salvati, Roberto; Hitti, Eric; Bellanger, Jean-Jacques; Saint-Jalmes, Hervé; Gambarota, Giulio

    2016-06-01

    Virtual Phantom Magnetic Resonance Imaging (ViP MRI) is a method to generate reference signals on MR images, using external radiofrequency (RF) signals. The aim of this study was to assess the feasibility of ViP MRI to generate complex-data images of phantoms mimicking water-fat systems. Various numerical phantoms with a given fat fraction, T2* and field map were designed. The k-space of numerical phantoms was converted into RF signals to generate virtual phantoms. MRI experiments were performed at 4.7T using a multi-gradient-echo sequence on virtual and physical phantoms. The data acquisition of virtual and physical phantoms was simultaneous. Decomposition of the water and fat signals was performed using a complex-based water-fat separation algorithm. Overall, a good agreement was observed between the fat fraction, T2* and phase map values of the virtual and numerical phantoms. In particular, fat fractions of 10.5±0.1 (vs 10% of the numerical phantom), 20.3±0.1 (vs 20%) and 30.4±0.1 (vs 30%) were obtained in virtual phantoms. The ViP MRI method allows for generating imaging phantoms that i) mimic water-fat systems and ii) can be analyzed with water-fat separation algorithms based on complex data. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. The Comparison of Virtual Water Consumption among the Various Consumption Patterns of Diet

    OpenAIRE

    SHANG Hai-yang

    2015-01-01

    Water resource is the basic and necessary input in the process of production and various consumption patterns of products and goods causes cause different impacts on the water resource using. It is very important to analysis and measures those different influences, which is especially good for the sustainability of water resource, construction of sustainable consumption pattern and the implementation of Integrated Water Resource Management. In this text, the virtual water consumption of Gansu...

  15. The Hydro-Economic Interdependency of Cities: Virtual Water Connections of the Phoenix, Arizona Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Richard R. Rushforth

    2015-06-01

    Full Text Available Water footprinting has revealed hydro-economic interdependencies between distant global geographies via trade, especially of agricultural and manufactured goods. However, for metropolitan areas, trade not only entails commodity flows at many scales from intra-municipal to global, but also substantial intra-metropolitan flows of the skilled labor that is essential to a city’s high-value economy. Virtual water flows between municipalities are directly relevant for municipal water supply policy and infrastructure investment because they quantify the hydro-economic dependency between neighboring municipalities. These municipalities share a physical water supply and also place demands on their neighbors’ water supplies by outsourcing labor and commodity production outside the municipal and water supply system boundary to the metropolitan area. Metropolitan area communities span dense urban cores to fringe agricultural towns, spanning a wide range of the US hydro-economy. This study quantifies water footprints and virtual water flows of the complete economy of the Phoenix Metropolitan Area’s municipalities. A novel approach utilized journey to work data to estimate virtual water flows embedded in labor. Commodities dominate virtual water flows at all scales of analysis, however labor is shown to be important for intra-metropolitan virtual water flows. This is the first detailed water footprint analysis of Phoenix, an important city in a water-scarce region. This study establishes a hydro-economic typology for communities to define several niche roles and decision making points of view. This study’s findings can be used to classify communities with respect to their relative roles, and to benchmark future improvements in water sustainability for all types of communities. More importantly, these findings motivate cooperative approaches to intra-metropolitan water supply policy that recognize the hydro-economic interdependence of these

  16. Global effects of local food-production crises: a virtual water perspective.

    Science.gov (United States)

    Tamea, Stefania; Laio, Francesco; Ridolfi, Luca

    2016-01-25

    By importing food and agricultural goods, countries cope with the heterogeneous global water distribution and often rely on water resources available abroad. The virtual displacement of the water used to produce such goods (known as virtual water) connects together, in a global water system, all countries participating to the international trade network. Local food-production crises, having social, economic or environmental origin, propagate in this network, modifying the virtual water trade and perturbing local and global food availability, quantified in terms of virtual water. We analyze here the possible effects of local crises by developing a new propagation model, parsimonious but grounded on data-based and statistically-verified assumptions, whose effectiveness is proved on the Argentinean crisis in 2008-09. The model serves as the basis to propose indicators of crisis impact and country vulnerability to external food-production crises, which highlight that countries with largest water resources have the highest impact on the international trade, and that not only water-scarce but also wealthy and globalized countries are among the most vulnerable to external crises. The temporal analysis reveals that global average vulnerability has increased over time and that stronger effects of crises are now found in countries with low food (and water) availability.

  17. Annual and Seasonal Mean Net Evaporation Rates of the Red Sea Water during Jan 1958 - Dec 2007

    OpenAIRE

    Nassir, Sahbaldeen Abdulaziz

    2012-01-01

    Data set including sea level, temperature, salinity, and current from Simple Ocean Data Assimilation (SODA) is used in this study to estimate the mean net annually and seasonally evaporation rates. Then wind data is used to examine its impact on the evaporation. This work calculated the seasonal and annual evaporation rates based on assumption of that there is no net mass transport (balanced). Hence, the difference in the transport supposed to be equal to the water that has eva...

  18. Modeling the Economic Feasibility of Large-Scale Net-Zero Water Management: A Case Study.

    Science.gov (United States)

    Guo, Tianjiao; Englehardt, James D; Fallon, Howard J

      While municipal direct potable water reuse (DPR) has been recommended for consideration by the U.S. National Research Council, it is unclear how to size new closed-loop DPR plants, termed "net-zero water (NZW) plants", to minimize cost and energy demand assuming upgradient water distribution. Based on a recent model optimizing the economics of plant scale for generalized conditions, the authors evaluated the feasibility and optimal scale of NZW plants for treatment capacity expansion in Miami-Dade County, Florida. Local data on population distribution and topography were input to compare projected costs for NZW vs the current plan. Total cost was minimized at a scale of 49 NZW plants for the service population of 671,823. Total unit cost for NZW systems, which mineralize chemical oxygen demand to below normal detection limits, is projected at ~$10.83 / 1000 gal, approximately 13% above the current plan and less than rates reported for several significant U.S. cities.

  19. Vulnerability of countries to food-production crises propagating in the virtual water trade network

    Science.gov (United States)

    Tamea, S.; Laio, F.; Ridolfi, L.

    2015-12-01

    In recent years, the international trade of food and agricultural commodities has undergone a marked increase of exchanged volumes and an expansion of the trade network. This globalization of trade has both positive and negative effects, but the interconnectedness and external dependency of countries generate complex dynamics which are often difficult to understand and model. In this study we consider the volume of water used for the production of agricultural commodities, virtually exchanged among countries through commodity trade, i.e. the virtual water trade. Then, we set up a parsimonious mechanistic model describing the propagation, into the global trade network, of food-production crises generated locally by a social, economic or environmental event (such as war, economic crisis, drought, pest). The model, accounting for the network structure and the virtual water balance of all countries, bases on rules derived from observed virtual water flows and on data-based and statistically verified assumption. It is also tested on real case studies that prove its capability to capture the main features of crises propagation. The model is then employed as the basis for the development of an index of country vulnerability, measuring the exposure of countries to crises propagating in the virtual water trade network. Results of the analysis are discussed within the context of socio-economic and environmental conditions of countries, showing that not only water-scarce, but also wealthy and globalized countries, are among the most vulnerable to external crises. The temporal analysis for the period 1986-2011 reveals that the global average vulnerability has strongly increased over time, confirming the increased exposure of countries to external crises which may occur in the virtual water trade network.

  20. Characterization of the phantom material virtual water in high-energy photon and electron beams.

    Science.gov (United States)

    McEwen, M R; Niven, D

    2006-04-01

    The material Virtual Water has been characterized in photon and electron beams. Range-scaling factors and fluence correction factors were obtained, the latter with an uncertainty of around 0.2%. This level of uncertainty means that it may be possible to perform dosimetry in a solid phantom with an accuracy approaching that of measurements in water. Two formulations of Virtual Water were investigated with nominally the same elemental composition but differing densities. For photon beams neither formulation showed exact water equivalence-the water/Virtual Water dose ratio varied with the depth of measurement with a difference of over 1% at 10 cm depth. However, by using a density (range) scaling factor very good agreement (water and Virtual Water at all depths was obtained. In the case of electron beams a range-scaling factor was also required to match the shapes of the depth dose curves in water and Virtual Water. However, there remained a difference in the measured fluence in the two phantoms after this scaling factor had been applied. For measurements around the peak of the depth-dose curve and the reference depth this difference showed some small energy dependence but was in the range 0.1%-0.4%. Perturbation measurements have indicated that small slabs of material upstream of a detector have a small (<0.1% effect) on the chamber reading but material behind the detector can have a larger effect. This has consequences for the design of experiments and in the comparison of measurements and Monte Carlo-derived values.

  1. Data Driven Estimation of Transpiration from Net Water Fluxes: the TEA Algorithm

    Science.gov (United States)

    Nelson, J. A.; Carvalhais, N.; Cuntz, M.; Delpierre, N.; Knauer, J.; Migliavacca, M.; Ogee, J.; Reichstein, M.; Jung, M.

    2017-12-01

    The eddy covariance method, while powerful, can only provide a net accounting of ecosystem fluxes. Particularly with water cycle components, efforts to partitioning total evapotranspiration (ET) into the biotic component (transpiration, T) and the abiotic component (here evaporation, E) have seen limited success, with no one method emerging as a standard.Here we demonstrate a novel method that uses ecosystem WUE to predict transpiration in two steps: (1) a filtration step that to isolate the signal of ET for periods where E is minimized and ET is likely dominated by the signal of T; and (2) a step which predicts the WUE using meteorological variables, as well as information derived from the carbon and energy fluxes. To assess the the underlying assumptions, we tested the proposed method on three ecological models, allowing validation where the underlying carbon:water relationships, as well as the transpiration estimates, are know.The partitioning method shows high correlation (R²>0.8) between Tmodel/ET and TTEA/ET across timescales from half-hourly to annually, as well as capturing spatial variability across sites. Apart from predictive performance, we explore the sensitivities of the method to the underlying assumptions, such as the effects of residual evaporation in the training dataset. Furthermore, we show initial transpiration estimates from the algorithm at global scale, via the FLUXNET dataset.

  2. Adapting rice production to climate change for sustainable blue water consumption: an economic and virtual water analysis

    Science.gov (United States)

    Darzi-Naftchali, Abdullah; Karandish, Fatemeh

    2017-12-01

    Sustainable utilization of blue water resources under climate change is of great significance especially for producing high water-consuming crops in water-scarce regions. Based on the virtual water concept, we carried out a comprehensive field-modeling research to find the optimal agricultural practices regarding rice blue water consumption under prospective climate change. The DSSAT-CERES-Rice model was used in combination with 20 GCMs under three Representative Concentration Pathways of low (RCP2.6), intermediate (RCP4.6), and very high (RCP8.5) greenhouse concentrations to predict rice yield and water requirement and related virtual water and economic return for the base and future periods. The crop model was calibrated and validated based on the 2-year field data obtained from consolidated paddy fields of the Sari Agricultural Sciences and Natural Resources University during 2011 and 2012 rice cropping cycles. Climate change imposes an increase of 0.02-0.04 °C in air temperature which consequently shifts rice growing seasons to winter season, and shorten the length of rice physiological maturity period by 2-15 days. While rice virtual water reduces by 0.1-20.6% during 2011-2070, reduced rice yield by 3.8-22.6% over the late twenty-first century results in a considerable increase in rice virtual water. By increasing the contribution of green water in supplying crop water requirement, earlier cropping could diminish blue water consumption for rice production in the region while cultivation postponement increases irrigation water requirement by 2-195 m3 ha-1. Forty days delay in rice cultivation in future will result in 29.9-40.6% yield reduction and 43.9-60% increase in rice virtual water under different scenarios. Earlier cropping during the 2011-2040 and 2041-2070 periods would increase water productivity, unit value of water, and economic value of blue water compared to the base period. Based on the results, management of rice cultivation calendar is a

  3. BACTERIA, BEACHES AND SWIMMABLE WATERS: INTRODUCING VIRTUAL BEACH

    Science.gov (United States)

    Safe beaches meet water quality standards and are valued for their aesthetics and the recreational opportunities that they afford. In the United States recreational water quality assessments and beach closure decisions are presently based on samples of enterococci or Escherichia ...

  4. Assessment of regional trade and virtual water flows in China

    OpenAIRE

    Dabo, G.; Hubacek, K.

    2007-01-01

    The success of Chinas economic development has left deep marks on resource availability and quality. Some regions in China are relatively poor with regards to water resources. This problem is exacerbated by economic growth. Flourishing trade activities on both domestic and international levels have resulted in significant amounts of water withdrawal and water pollution. Hence the goal of this paper is to evaluate the current inter-regional trade structure and its effects on water consumption ...

  5. Evaluating the Life Cycle Environmental Benefits and Trade-Offs of Water Reuse Systems for Net-Zero Buildings.

    Science.gov (United States)

    Hasik, Vaclav; Anderson, Naomi E; Collinge, William O; Thiel, Cassandra L; Khanna, Vikas; Wirick, Jason; Piacentini, Richard; Landis, Amy E; Bilec, Melissa M

    2017-02-07

    Aging water infrastructure and increased water scarcity have resulted in higher interest in water reuse and decentralization. Rating systems for high-performance buildings implicitly promote the use of building-scale, decentralized water supply and treatment technologies. It is important to recognize the potential benefits and trade-offs of decentralized and centralized water systems in the context of high-performance buildings. For this reason and to fill a gap in the current literature, we completed a life cycle assessment (LCA) of the decentralized water system of a high-performance, net-zero energy, net-zero water building (NZB) that received multiple green building certifications and compared the results with two modeled buildings (conventional and water efficient) using centralized water systems. We investigated the NZB's impacts over varying lifetimes, conducted a break-even analysis, and included Monte Carlo uncertainty analysis. The results show that, although the NZB performs better in most categories than the conventional building, the water efficient building generally outperforms the NZB. The lifetime of the NZB, septic tank aeration, and use of solar energy have been found to be important factors in the NZB's impacts. While these findings are specific to the case study building, location, and treatment technologies, the framework for comparison of water and wastewater impacts of various buildings can be applied during building design to aid decision making. As we design and operate high-performance buildings, the potential trade-offs of advanced decentralized water treatment systems should be considered.

  6. Progress in design and analysis of the net water cooled liquid breeder blanket

    International Nuclear Information System (INIS)

    Danner, W.; Rieger, M.; Verschuur, K.A.; Vieider, G.; Casini, G.; Chazalon, M.; Libin, B.; Farfaletti-Casali, F.; Piana, R.

    1987-01-01

    The NET liquid breeder blanket was subjected to a major design revision and integrated in the new NET-DN machine configuration. In this paper briefly the most essential design features are summarized and some results from thermohydraulics and 1D as well as 3D neutronics analyses are presented. It is concluded that the performance meets well the requirements of NET but that the concept needs substantial improvement if applied to a reactor

  7. COST-EFFECTIVE APPROACH TO ESTIMATE UNREPORTED DATA: REBUILDING HISTORY OF LIFT-NET FISHING IN KWANDANG WATERS

    Directory of Open Access Journals (Sweden)

    Andhika Prima Prasetyo

    2014-12-01

    Full Text Available This paper aims to develop cost-effective approach regarding the estimation unreported annual catch data of lift-net fishery using Google Earth imagery. Lift net fishery is one of the main fishing activities of coastal community in Kwandang Bay, it has been faced problem of uncertain fisheries status due to limited recorded data. Combination of a Monte Carlo procedure was applied by involving couple of assumptions on parameters such as estimate growth rate of the total number of lift-net per years (10%, day at sea per unit per month (21 days and operated lift-net per month (50% and 80%. The results showed that 101 units of lift-nets were found around Kwandang waters based on Google Earth imagery recorded in October, 7th 2010, and this were used as a benchmark of calculation. This prediction was 28 units higher than official data from North Gorontalo District of Marine Affairs and Fisheries Services (DKP Gorontalo Utara. Compared with capture fisheries statistics issued by Kwandang CFP, the estimated lift-net catches based on two-scenarios represent additional catches of 46 % and 86 %. These results suggested and could be used as a correction index to improve the reliability of Kwandang District officially reported fisheries statistics as a baseline to develop a local common fisheries policy.

  8. Water and energy link in the cities of the future - achieving net zero carbon and pollution emissions footprint.

    Science.gov (United States)

    Novotny, V

    2011-01-01

    This article discusses the link between water conservation, reclamation, reuse and energy use as related to the goal of achieving the net zero carbon emission footprint in future sustainable cities. It defines sustainable ecocities and outlines quantitatively steps towards the reduction of energy use due to water and used water flows, management and limits in linear and closed loop water/stormwater/wastewater management systems. The three phase water energy nexus diagram may have a minimum inflection point beyond which reduction of water demand may not result in a reduction of energy and carbon emissions. Hence, water conservation is the best alternative solution to water shortages and minimizing the carbon footprint. A marginal water/energy chart is developed and proposed to assist planners in developing future ecocities and retrofitting older communities to achieve sustainability.

  9. Importance of the virtual mass force in accelerating steam/water mixtures

    International Nuclear Information System (INIS)

    Khalil, Y.F.; Kazimi, M.S.

    1987-01-01

    Virtual mass force is one of the forces that must be considered against accelerating a dispersed fluid flowing in the bulk of a continuous fluid. This force depends on the geometry of the interface and the flow pattern of the two fluids. For dilute two-phase flow mixtures where the bubbles are singly dispersed, the value of the virtual mass force coefficient is dependent on the geometry of the bubble. However, for high void fraction cases, such as depressurization initiated by a pipe break in light water reactors, more intense interaction is expected between the two phase and, therefore, the value of the virtual mass force must be well defined. The effects of implementing the virtual mass force term in the momentum equations of a two-fluid model may be significant for improving the stability of the solution of the conservation equations, the accuracy of the numerical results, and the computation time. In the current work, a new stability criterion is derived after implementing Hancox's model for the virtual mass force in the momentum equations of the six-equation two-phase flow model of TERMIT. A one-dimensional blow-down in a horizontal pipe is considered to investigate the importance of incorporating the virtual mass force in accelerating mixtures flows

  10. To trade or not to trade: Link prediction in the virtual water network

    Science.gov (United States)

    Tuninetti, Marta; Tamea, Stefania; Laio, Francesco; Ridolfi, Luca

    2017-12-01

    In the international trade network, links express the (temporary) presence of a commercial exchange of goods between any two countries. Given the dynamical behaviour of the trade network, where links are created and dismissed every year, predicting the link activation/deactivation is an open research question. Through the international trade network of agricultural goods, water resources are 'virtually' transferred from the country of production to the country of consumption. We propose a novel methodology for link prediction applied to the network of virtual water trade. Starting from the assumption of having links between any two countries, we estimate the associated virtual water flows by means of a gravity-law model using country and link characteristics as drivers. We consider the links with estimated flows higher than 1000 m3/year as active links, while the others as non-active links. Flows traded along estimated active links are then re-estimated using a similar but differently-calibrated gravity-law model. We were able to correctly model 84% of the existing links and 93% of the non-existing links in year 2011. It is worth to note that the predicted active links carry 99% of the global virtual water flow; hence, missed links are mainly those where a minimum volume of virtual water is exchanged. Results indicate that, over the period from 1986 to 2011, population, geographical distances between countries, and agricultural efficiency (through fertilizers use) are the major factors driving the link activation and deactivation. As opposed to other (network-based) models for link prediction, the proposed method is able to reconstruct the network architecture without any prior knowledge of the network topology, using only the nodes and links attributes; it thus represents a general method that can be applied to other networks such as food or value trade networks.

  11. Past, current and future water footprints, water scarcity and virtual water flows in China

    NARCIS (Netherlands)

    Zhuo, L.

    2016-01-01

    The increasing water consumption as a result of population growth and economic development, especially in fast growing developing countries, puts an increasing strain on the sustainable use of the globe’s finite freshwater resources and poses a key challenge for the future. The objective of the

  12. Net ion fluxes in the facultative air-breather Hoplosternum littorale (tamoata) and the obligate air-breather Arapaima gigas (pirarucu) exposed to different Amazonian waters.

    Science.gov (United States)

    Baldisserotto, Bernardo; Copatti, Carlos E; Gomes, Levy C; Chagas, Edsandra C; Brinn, Richard P; Roubach, Rodrigo

    2008-12-01

    Fishes that live in the Amazon environment may be exposed to several kinds of water: black water (BW), acidic black water (pH 3.5) (ABW) and white water (WW), among others. The aim of the present study was to analyze net ion fluxes in the facultative air-breather Hoplosternum littorale (tamoata) and the obligate air-breather Arapaima gigas (pirarucu) exposed to different types of water. Fishes were acclimated in well water and later placed in individual chambers containing one type of water for ion flux measurements. After 4 h, the water in the chambers was replaced by a different type of water. The transfer of both species to ABW (independent of previous water exposure) increased net ion loss. Tamoatas transferred from ABW to BW or WW presented a net ion influx, but pirarucus showed only small changes on net ion efflux. These results allow us to conclude that tamoatas and pirarucus present differences in terms of ion regulation but that the general aspects of the ion flux are similar: (1) exposure to ABW led to net ion loss; (2) transfer from BW to WW or vice-versa induced only minor changes on net ion fluxes. These observations demonstrate that any osmoregulatory difficulties encountered by either species during changes between these latter two waters can be easily overcome.

  13. Thixotropic Phenomena in Water: Quantitative Indicators of Casimir-Magnetic Transformations from Vacuum Oscillations (Virtual Particles

    Directory of Open Access Journals (Sweden)

    Michael A. Persinger

    2015-09-01

    Full Text Available The ~1.5 × 10−20 J which is considered a universal quantity and is associated with the movement of protons in water also relates to the ratio of the magnetic moment of a proton divided by its unit charge, multiplied by viscosity and applied over the O-H distance. There is quantitative evidence that thixotropy, the “spontaneous” increased viscosity in water when undisturbed, originates from the transformation of virtual particles or vacuum oscillations to real states through conversion of Casimir-magnetic energies that involve the frequency of the neutral hydrogen line and the upper bound threshold value for intergalactic magnetic fields. The results indicate that ½ of a single electron orbit is real (particle and the other ½ is virtual (wave. The matter equivalent per s for virtual-to-real states for electrons in 1 mL of water with a neutral pH is consistent with the numbers of protons (H+ and the measured range of molecules in the coherent domains for both width and duration of growth and is similar to widths of intergalactic dust grains from which planets and stars may condense. The de Broglie momentum for the lower boundary of the width of coherent domains multiplied by the fine structure velocity of an electron is concurrent with the quantum when one proton is being removed from another and when the upper boundary of the rest mass of a photon is transformed by the product of velocities for putative “entanglement” and light. Theoretical and experimental results indicate that components of thixotropy, such as specific domains of intercalated water molecules, could display excess correlations over very large distances. Because the energies of the universal quantity and water converge it may be a special conduit for discrete transformations from virtual to real states.

  14. Going against the flow: A critical analysis of virtual water trade in the context of India's National River Linking Programme

    NARCIS (Netherlands)

    Verma, Shilp; Kampman, Doeke A.; van der Zaag, Pieter; Hoekstra, Arjen Ysbert

    2008-01-01

    Virtual water trade has been promoted as a tool to address national and regional water scarcity. In the context of international (food) trade, this concept has been applied with a view to optimize the flow of commodities considering the water endowments of nations. The concept states that water-rich

  15. Declarative virtual water maze learning and emotional fear conditioning in primary insomnia.

    Science.gov (United States)

    Kuhn, Marion; Hertenstein, Elisabeth; Feige, Bernd; Landmann, Nina; Spiegelhalder, Kai; Baglioni, Chiara; Hemmerling, Johanna; Durand, Diana; Frase, Lukas; Klöppel, Stefan; Riemann, Dieter; Nissen, Christoph

    2018-05-02

    Healthy sleep restores the brain's ability to adapt to novel input through memory formation based on activity-dependent refinements of the strength of neural transmission across synapses (synaptic plasticity). In line with this framework, patients with primary insomnia often report subjective memory impairment. However, investigations of memory performance did not produce conclusive results. The aim of this study was to further investigate memory performance in patients with primary insomnia in comparison to healthy controls, using two well-characterized learning tasks, a declarative virtual water maze task and emotional fear conditioning. Twenty patients with primary insomnia according to DSM-IV criteria (17 females, three males, 43.5 ± 13.0 years) and 20 good sleeper controls (17 females, three males, 41.7 ± 12.8 years) were investigated in a parallel-group study. All participants completed a hippocampus-dependent virtual Morris water maze task and amygdala-dependent classical fear conditioning. Patients with insomnia showed significantly delayed memory acquisition in the virtual water maze task, but no significant difference in fear acquisition compared with controls. These findings are consistent with the notion that memory processes that emerge from synaptic refinements in a hippocampal-neocortical network are particularly sensitive to chronic disruptions of sleep, while those in a basic emotional amygdala-dependent network may be more resilient. © 2018 European Sleep Research Society.

  16. Arius kesslerl & Sciadeops troschelii (Pisces: Ariidae growth in floating net cages in estuarine waters of Buenventura Bay-Colombia

    Directory of Open Access Journals (Sweden)

    Efraín Alfonso Rubio

    1999-07-01

    Full Text Available Two species of estuary catfish the Arius kessleri (CoCoCo and the Sciadeops troschelii (Nato were held in floating net cages at varying densities in estuarine waters of Buenventura Bay-Colombia. After 120 days for the Cococo had weights of 84.1 g Y64 g with densities of 5 and 30 specimen/rn'. The growth average was 0.58-0.39 g/day; the net yield obtained vary from 0.35 to 1.16 Kg/m', the food conversion ratio vary from 3.3 to 5.0 and de survival rate vary from 86% to 100%. With the Nato we obtained weights of 164 and 184 g, beginning with weights of 41 and 108 g their growth average vary from 0.50 to 0.82 g/day. The net yield obtained vary from 0.58 to 0.75 Kg/m' and the survival rate vary from 83% to 100%. From these results we conclude that the two species of catfish studied are strong species but they do not offer good possibilities for fish farming in estuarine waters.

  17. Virtual water flows and water-footprint of agricultural crop production, import and export: A case study for Israel.

    Science.gov (United States)

    Shtull-Trauring, E; Bernstein, N

    2018-05-01

    Agriculture is the largest global consumer of freshwater. As the volume of international trade continues to rise, so does the understanding that trade of water-intensive crops from areas with high precipitation, to arid regions can help mitigate water scarcity, highlighting the importance of crop water accounting. Virtual-Water, or Water-Footprint [WF] of agricultural crops, is a powerful indicator for assessing the extent of water use by plants, contamination of water bodies by agricultural practices and trade between countries, which underlies any international trade of crops. Most available studies of virtual-water flows by import/export of agricultural commodities were based on global databases, which are considered to be of limited accuracy. The present study analyzes the WF of crop production, import, and export on a country level, using Israel as a case study, comparing data from two high-resolution local databases and two global datasets. Results for local datasets demonstrate a WF of ~1200Million Cubic Meters [MCM]/year) for total crop production, ~1000MCM/year for import and ~250MCM/year for export. Fruits and vegetables comprise ~80% of Export WF (~200MCM/year), ~50% of crop production and only ~20% of the imports. Economic Water Productivity [EWP] ($/m 3 ) for fruits and vegetables is 1.5 higher compared to other crops. Moreover, the results based on local and global datasets varied significantly, demonstrating the importance of developing high-resolution local datasets based on local crop coefficients. Performing high resolution WF analysis can help in developing agricultural policies that include support for low WF/high EWP and limit high WF/low EWP crop export, where water availability is limited. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Net ecosystem exchange of carbon dioxide and water of far eastern Siberian Larch (Larix cajanderii on permafrost

    Directory of Open Access Journals (Sweden)

    A. J. Dolman

    2004-01-01

    Full Text Available Observations of the net ecosystem exchange of water and CO2 were made during two seasons in 2000 and 2001 above a Larch forest in Far East Siberia (Yakutsk. The measurements were obtained by eddy correlation. There is a very sharply pronounced growing season of 100 days when the forest is leaved. Maximum half hourly uptake rates are 18 µmol m-2 s-1; maximum respiration rates are 5 µmol m-2 s-1. Net annual sequestration of carbon was estimated at 160 gCm-2 in 2001. Applying no correction for low friction velocities added 60 g C m-2. The net carbon exchange of the forest was extremely sensitive to small changes in weather that may switch the forest easily from a sink to a source, even in summer. June was the month with highest uptake in 2001. The average evaporation rate of the forest approached 1.46 mm day-1 during the growing season, with peak values of 3 mm day-1 with an estimated annual evaporation of 213 mm, closely approaching the average annual rainfall amount. 2001 was a drier year than 2000 and this is reflected in lower evaporation rates in 2001 than in 2000. The surface conductance of the forest shows a marked response to increasing atmospheric humidity deficits. This affects the CO2 uptake and evaporation in a different manner, with the CO2 uptake being more affected. There appears to be no change in the relation between surface conductance and net ecosystem uptake normalized by the atmospheric humidity deficit at the monthly time scale. The response to atmospheric humidity deficit is an efficient mechanism to prevent severe water loss during the short intense growing season. The associated cost to the sequestration of carbon may be another explanation for the slow growth of these forests in this environment.

  19. Application of the Forhyd model to simulate net precipitation and intercepted water evaporation in forest canopies in Colombian amazonia

    International Nuclear Information System (INIS)

    Tellez Guio, Patricia; Boschell Villamarin, Francisco; Tobon Marin, Conrado

    2005-01-01

    Hydrologic simulation is a technique, which allows us to understand the relationships among hydrological, biological and ecological variables in an ecosystem. In this research, the FORHYD model is used to simulate the net precipitation and the water intercepted by the canopies of a mature forest, a 30-year old secondary forest, an 18-year old secondary forest, a 5-year old secondary forest, and a shifting cultivation plot, all located in Colombia's amazonia. The model calculates the water budget of the canopy by using the precipitation rates, canopy drainage and evaporation of the water intercepted by the canopy. This paper is the second one in a series of papers reporting the results of the research on the simulation of the hydrological fluxes in three different land use types of Colombian amazonia. The research was carried out in middle Caqueta of Colombian amazonia (northwest amazon basin). The FORHYD model was calibrated and validated by using field observations of the climate, net precipitation (PT), thoughtful (TH) and stem flow (ST), which were monitored during a period of 15 months from March 2001 to June 2002. These observations were used as both input variables and diagnostic variables to probe the model's precision to simulate field observations. Results showed that FORHYD simulates with a good precision the net precipitation and the evaporation of the water intercepted by the canopy. However, the model's precision depends on a good parameterization, which in turn depends on a good database of field observations. The model is a good tool for simulating the hydrological cycle and can be used to simulate critical scenarios of climate variability

  20. Aerobic fitness relates to learning on a virtual morris water task and hippocampal volume in adolescents

    Science.gov (United States)

    Herting, Megan M.; Nagel, Bonnie J.

    2012-01-01

    In rodents, exercise increases hippocampal neurogenesis and allows for better learning and memory performance on water maze tasks. While exercise has also been shown to be beneficial for the brain and behavior in humans, no study has examined how exercise impacts spatial learning using a directly translational water maze task, or if these relationships exist during adolescence – a developmental period which the animal literature has shown to be especially vulnerable to exercise effects. In this study, we investigated the influence of aerobic fitness on hippocampal size and subsequent learning and memory, including visuospatial memory using a human analogue of the Morris Water Task, in 34 adolescents. Results showed that higher aerobic fitness predicted better learning on the virtual Morris Water Task and larger hippocampal volumes. No relationship between virtual Morris Water Task memory recall and aerobic fitness was detected. Aerobic fitness, however, did not relate to global brain volume, or verbal learning, which might suggest some specificity of the influence of aerobic fitness on the adolescent brain. This study provides a direct translational approach to the existing animal literature on exercise, as well as adds to the sparse research that exists on how aerobic exercise impacts the developing human brain and memory. PMID:22610054

  1. Aerobic fitness relates to learning on a virtual Morris Water Task and hippocampal volume in adolescents.

    Science.gov (United States)

    Herting, Megan M; Nagel, Bonnie J

    2012-08-01

    In rodents, exercise increases hippocampal neurogenesis and allows for better learning and memory performance on water maze tasks. While exercise has also been shown to be beneficial for the brain and behavior in humans, no study has examined how exercise impacts spatial learning using a directly translational water maze task, or if these relationships exist during adolescence--a developmental period which the animal literature has shown to be especially vulnerable to exercise effects. In this study, we investigated the influence of aerobic fitness on hippocampal size and subsequent learning and memory, including visuospatial memory using a human analogue of the Morris Water Task, in 34 adolescents. Results showed that higher aerobic fitness predicted better learning on the virtual Morris Water Task and larger hippocampal volumes. No relationship between virtual Morris Water Task memory recall and aerobic fitness was detected. Aerobic fitness, however, did not relate to global brain volume or verbal learning, which might suggest some specificity of the influence of aerobic fitness on the adolescent brain. This study provides a direct translational approach to the existing animal literature on exercise, as well as adds to the sparse research that exists on how aerobic exercise impacts the developing human brain and memory. Published by Elsevier B.V.

  2. Applying the input-output method to account for water footprint and virtual water trade in the Haihe River basin in China.

    Science.gov (United States)

    Zhao, Xu; Yang, Hong; Yang, Zhifeng; Chen, Bin; Qin, Yan

    2010-12-01

    The virtual water strategy which advocates importing water intensive products and exporting products with low water intensity is gradually accepted as one of the options for solving water crisis in severely water scarce regions. However, if we count the virtual water embodied in imported products as the water saved for a region, we might overestimate the saving by including the virtual water that is later re-exported in association with the proceeded products made from the originally imported products. This problem can be avoided by accounting for the saved water through calculating water footprint (WF) in domestic final consumptive products. In this paper, an input-output analysis (IOA) based on the water footprint accounting framework is built to account for WF and virtual water trade of final consumptive products in the water stressed Haihe River basin in China for the year 1997, 2000, and 2002. The input-output transaction tables of the three years are constructed. The results show WF of 46.57, 44.52, and 42.71 billion m(3) for the three years, respectively. These volumes are higher than the water used directly in the corresponding years in the basin. A WF intensity (WFI) indicator is then used to assess if the economic activities in the basin are consistent with the virtual water strategy. The temporal change of the WFI is also decomposed by the index number analysis method. The results showed that the basin was silently importing virtual water through the trade of raw and processed food commodities under the background of the whole economic circulation.

  3. Analysis of virtual water flows associated with the trade of maize in the SADC region: importance of scale

    CSIR Research Space (South Africa)

    Dabrowski, James M

    2009-10-01

    Full Text Available The concept of virtual water encourages a country to view agricultural crops in terms of the amount of water required to produce those crops, with a view to implementing trading policies that promote the saving of scarce water resources. Recently...

  4. Zooplankton and other data collected from net casts in Coastal Waters of California from T-441; 19 April 1967 to 13 September 1967 (NODC Accession 7101507)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton and other data were collected using net casts from T-441 in the Coastal Waters of California. Data were collected from 19 April 1967 to 13 September 1967...

  5. Improvements to water use and water stress estimates with the addition of IR and net radiometers to weather stations

    Science.gov (United States)

    Evapotranspiration (ET) is often estimated with the Penman-Monteith (P-M) equation. Net radiation (Rn) is a major component of the surface energy balance and an input to the P-M equation, but it is challenging and expensive to measure accurately. For these reasons, most weather stations do not inclu...

  6. Hydrogen Economy Model for Nearly Net-Zero Cities with Exergy Rationale and Energy-Water Nexus

    Directory of Open Access Journals (Sweden)

    Birol Kılkış

    2018-05-01

    Full Text Available The energy base of urban settlements requires greater integration of renewable energy sources. This study presents a “hydrogen city” model with two cycles at the district and building levels. The main cycle comprises of hydrogen gas production, hydrogen storage, and a hydrogen distribution network. The electrolysis of water is based on surplus power from wind turbines and third-generation solar photovoltaic thermal panels. Hydrogen is then used in central fuel cells to meet the power demand of urban infrastructure. Hydrogen-enriched biogas that is generated from city wastes supplements this approach. The second cycle is the hydrogen flow in each low-exergy building that is connected to the hydrogen distribution network to supply domestic fuel cells. Make-up water for fuel cells includes treated wastewater to complete an energy-water nexus. The analyses are supported by exergy-based evaluation metrics. The Rational Exergy Management Efficiency of the hydrogen city model can reach 0.80, which is above the value of conventional district energy systems, and represents related advantages for CO2 emission reductions. The option of incorporating low-enthalpy geothermal energy resources at about 80 °C to support the model is evaluated. The hydrogen city model is applied to a new settlement area with an expected 200,000 inhabitants to find that the proposed model can enable a nearly net-zero exergy district status. The results have implications for settlements using hydrogen energy towards meeting net-zero targets.

  7. Estimating net rainfall, evaporation and water storage of a bare soil from sequential L-band emissivities

    Science.gov (United States)

    Stroosnijder, L.; Lascano, R. J.; Newton, R. W.; Vanbavel, C. H. M.

    1984-01-01

    A general method to use a time series of L-band emissivities as an input to a hydrological model for continuously monitoring the net rainfall and evaporation as well as the water content over the entire soil profile is proposed. The model requires a sufficiently accurate and general relation between soil emissivity and surface moisture content. A model which requires the soil hydraulic properties as an additional input, but does not need any weather data was developed. The method is shown to be numerically consistent.

  8. The Influence of CO2 Enrichment on Net Photosynthesis of Seagrass Zostera marina in a Brackish Water Environment

    OpenAIRE

    Pajusalu, Liina; Martin, Georg; Põllumäe, Arno; Paalme, Tiina

    2016-01-01

    Seagrasses are distributed across the globe and their communities may play key roles in the coastal ecosystems. Seagrass meadows are expected to benefit from the increased carbon availability which might be used in photosynthesis in a future high CO2 world. The main aim of this study was to examine the effect of elevated pCO2 on the net photosynthesis of seagrass Zostera marina in a brackish water environment. The short-term mesocosm experiments were conducted in Kõiguste Bay (northern part o...

  9. Effect of river discharge and geometry on tides and net water transport in an estuarine network, an idealized model applied to the Yangtze Estuary

    NARCIS (Netherlands)

    Alebregtse, N. C.|info:eu-repo/dai/nl/345704304; de Swart, H. E.|info:eu-repo/dai/nl/073449725

    2016-01-01

    Tidal propagation in, and division of net water transport over different channels in an estuarine network are analyzed using a newly developed idealized model. The water motion in this model is governed by the cross-sectionally averaged shallow water equations and is forced by tides at the seaward

  10. Projections of Virtual Water Trade Under Agricultural Policy Scenarios in China

    Science.gov (United States)

    Dalin, C.; Hanasaki, N.; Qiu, H.; Mauzerall, D. L.; Rodriguez-Iturbe, I.

    2014-12-01

    China's economic growth is expected to continue into the next decades, accompanied by a sustained urbanization and industrialization. The associated increase in demand for land, water resources and rich foods will deepen the challenge to sustainably feed the population and balance environmental and agricultural policies. In previous work, Inner Mongolia was identified as a target province for trade or agricultural policies aimed at water-use efficiency improvements, due to its large production relying on particularly significant irrigation water use. In addition, water scarcity issues may arises in the greater Beijing area, which represents the largest urban area of arid Northern China. Increasing residential and industrial water demand in this region may lead to fewer available water for irrigation. For these reasons, it is important to estimate the impacts of specific policies aiming at reducing excessive water use for crop production in Inner Mongolia, as well as exploring ways to mitigate pressure on water resources in dry urban areas. In this study, we use socio-economic projections to assess the future state of China's virtual water trade (VWT) network. We then quantify the effects of agricultural policies on the national VWT system and on the efficiency of food trade in terms of water resources. This study addresses the following questions: (1) How future socio-economic changes will affect China's food trade and associated water transfers? (2) To which extent localized reductions of irrigated area can decrease agricultural water use while maintaining national food security? (3) How would these policies affect China's domestic and international VWT network and induced water resources savings (losses)?

  11. On the Role of Hyper-arid Regions within the Virtual Water Trade Network

    Science.gov (United States)

    Aggrey, James; Alshamsi, Aamena; Molini, Annalisa

    2016-04-01

    Climate change, economic development, and population growth are bound to increasingly impact global water resources, posing a significant threat to the sustainable development of arid regions, where water consumption highly exceeds the natural carrying capacity, population growth rate is high, and climate variability is going to impact both water consumption and availability. Virtual Water Trade (VWT) - i.e. the international trade network of water-intensive products - has been proposed as a possible solution to optimize the allocation of water resources on the global scale. By increasing food availability and lowering food prices it may in fact help the rapid development of water-scarce regions. The structure of the VWT network has been analyzed by a number of authors both in connection with trade policies, socioeconomic constrains and agricultural efficiency. However a systematic analysis of the structure and the dynamics of the VWT network conditional to aridity, climatic forcing and energy availability, is still missing. Our goal is hence to analyze the role of arid and hyper-arid regions within the VWN under diverse climatic, demographic, and energy constraints with an aim to contribute to the ongoing Energy-Water-Food nexus discussion. In particular, we focus on the hyper-arid lands of the Arabian Peninsula, the role they play in the global network and the assessment of their specific criticalities, as reflected in the VWN resilience.

  12. Carbon dioxide addition to coral reef waters suppresses net community calcification

    Science.gov (United States)

    Albright, Rebecca; Takeshita, Yuichiro; Koweek, David A.; Ninokawa, Aaron; Wolfe, Kennedy; Rivlin, Tanya; Nebuchina, Yana; Young, Jordan; Caldeira, Ken

    2018-03-01

    Coral reefs feed millions of people worldwide, provide coastal protection and generate billions of dollars annually in tourism revenue. The underlying architecture of a reef is a biogenic carbonate structure that accretes over many years of active biomineralization by calcifying organisms, including corals and algae. Ocean acidification poses a chronic threat to coral reefs by reducing the saturation state of the aragonite mineral of which coral skeletons are primarily composed, and lowering the concentration of carbonate ions required to maintain the carbonate reef. Reduced calcification, coupled with increased bioerosion and dissolution, may drive reefs into a state of net loss this century. Our ability to predict changes in ecosystem function and associated services ultimately hinges on our understanding of community- and ecosystem-scale responses. Past research has primarily focused on the responses of individual species rather than evaluating more complex, community-level responses. Here we use an in situ carbon dioxide enrichment experiment to quantify the net calcification response of a coral reef flat to acidification. We present an estimate of community-scale calcification sensitivity to ocean acidification that is, to our knowledge, the first to be based on a controlled experiment in the natural environment. This estimate provides evidence that near-future reductions in the aragonite saturation state will compromise the ecosystem function of coral reefs.

  13. Simulation of the chemical stage in water radiolysis with the help of Continuous Petri nets

    International Nuclear Information System (INIS)

    Barilla, J.; Lokajíček, M.V.; Pisaková, H.; Simr, P.

    2014-01-01

    The final biological effect of ionizing particles may be influenced often strongly by some chemical substances present in cells during irradiation by low-LET radiation. It may occur during the chemical stage of the given process, due to chemical reactions of radicals running in the given process. However, the whole chemical process may be hardly described sufficiently with the help of the usual approach based on the deterministic diffusion-kinetic computations and the stochastic Monte-Carlo simulations. We have proposed already earlier a model describing the processes (i.e., the combined effect of cluster diffusion and chemical reactions) running in individual radical clusters that might be responsible for corresponding damages of DNA molecules (i.e., formation of DSBs). Now a further generalization of the given model (using Continuous Petri nets) will be presented that makes it possible to characterize more detailed behavior of individual radicals in corresponding clusters, which might be useful especially for low-LET radiation when individual radical clusters meet a DNA molecule at different time intervals after their formation; the decreasing presence of individual radicals in corresponding clusters being established. In this paper we shall focus on the design of the corresponding mathematical model and its application; the comparison of corresponding results with experimental data obtained in the case of deoxygenated system will be presented. - Highlights: • Creation of the mathematical model. • Realization of the model with the help of Continuous Petri nets. • Obtain the time dependence of changes in the concentration of radicals

  14. Optimization of crude protein in diets for Nile tilapia reared in net pens: performance, hematology, and water quality

    Directory of Open Access Journals (Sweden)

    Débora Del Puppo

    Full Text Available ABSTRACT: Two experiments were conducted to evaluate the effects of reducing dietary crude protein (CP, based on the ideal protein concept for Nile tilapia reared in net pens. The experimental (isocaloric, isocalcium, and isophosphoric diets were formulated to contain 270, 300, 330, and 360g kg-1 CP. In experiment 1, 4320 Nile tilapia (13.5±0.82g were used to evaluate the performance and hematological parameters. The experimental design was completely randomized and the fish were distributed in 24 net pens (1.0m3, with four diets, six replicates, and 180 fishes per experimental unit. In experiment 2, 40 Nile tilapia (22.5±0.56g were used to evaluate the ammonia excretion. Fish were distributed in 40 aquaria (3.0L, with one fish per aquarium (n=10. No protein reduction effect was observed in feed intake and the hematocrit and hemoglobin values. Regarding the statistic models used in the present study, difference was observed between CP values. The optimal level estimated by the quadratic equation first interception with the linear response plateau (LRP as a response to CP changes in the diet was determined for weight gain (324.3g kg-1 and feed conversion (317.8g kg-1. After reduction in the CP levels, a linear reduction was observed in the ammonia excretion in water. Based on the ideal protein concept for Nile tilapia reared in net pens, reducing the CP levels in the diets is possible, without change in the performance and hematological parameters, and with a reduction in the levels of ammonia excretion in water, since amino acids are supplemented.

  15. Heavy Analysis and Light Virtualization of Water Use Data with Python

    Science.gov (United States)

    Kim, H.; Bijoor, N.; Famiglietti, J. S.

    2014-12-01

    Water utilities possess a large amount of water data that could be used to inform urban ecohydrology, management decisions, and conservation policies, but such data are rarely analyzed owing to difficulty in analyzation, visualization, and interpretion. We have developed a high performance computing resource for this purpose. We partnered with 6 water agencies in Orange County who provided 10 years of parcel-level monthly water use billing data for a pilot study. The first challenge that we overcame was to refine all human errors and unify the many different formats of data over all agencies. Second, we tested and applied experimental approaches to the data, including complex calculations, with high efficiency. Third, we developed a method to refine the data so it can be browsed along a time series index and/or geo-spatial queries with high efficiency, no matter how large the data. Python scientific libraries were the best match to handle arbitrary data sets in our environment. Further milestones include agency entry, sets of formulae, and maintaining 15M rows X 70 columns of data with high performance of cpu-bound processes. To deal with billions of rows, we performed an analysis virtualization stack by leveraging iPython parallel computing. With this architecture, one agency could be considered one computing node or virtual machine that maintains its own data sets respectively. For example, a big agency could use a large node, and a small agency could use a micro node. Under the minimum required raw data specs, more agencies could be analyzed. The program developed in this study simplifies data analysis, visualization, and interpretation of large water datasets, and can be used to analyze large data volumes from water agencies nationally or worldwide.

  16. Leaf water relations and net gas exchange responses of salinized Carrizo citrange seedlings during drought stress and recovery.

    Science.gov (United States)

    Pérez-Pérez, J G; Syvertsen, J P; Botía, P; García-Sánchez, F

    2007-08-01

    Since salinity and drought stress can occur together, an assessment was made of their interacting effects on leaf water relations, osmotic adjustment and net gas exchange in seedlings of the relatively chloride-sensitive Carrizo citrange, Citrus sinensis x Poncirus trifoliata. Plants were fertilized with nutrient solution with or without additional 100 mm NaCl (salt and no-salt treatments). After 7 d, half of the plants were drought stressed by withholding irrigation water for 10 d. Thus, there were four treatments: salinized and non-salinized plants under drought-stress or well-watered conditions. After the drought period, plants from all stressed treatments were re-watered with nutrient solution without salt for 8 d to study recovery. Leaf water relations, gas exchange parameters, chlorophyll fluorescence, proline, quaternary ammonium compounds and leaf and root concentrations of Cl(-) and Na(+) were measured. Salinity increased leaf Cl(-) and Na(+) concentrations and decreased osmotic potential (Psi(pi)) such that leaf relative water content (RWC) was maintained during drought stress. However, in non-salinized drought-stressed plants, osmotic adjustment did not occur and RWC decreased. The salinity-induced osmotic adjustment was not related to any accumulation of proline, quaternary ammonium compounds or soluble sugars. Net CO(2) assimilation rate (A(CO2)) was reduced in leaves from all stressed treatments but the mechanisms were different. In non-salinized drought-stressed plants, lower A(CO2) was related to low RWC, whereas in salinized plants decreased A(CO2) was related to high levels of leaf Cl(-) and Na(+). A(CO2) recovered after irrigation in all the treatments except in previously salinized drought-stressed leaves which had lower RWC and less chlorophyll but maintained high levels of Cl(-), Na(+) and quaternary ammonium compounds after recovery. High leaf levels of Cl(-) and Na(+) after recovery apparently came from the roots. Plants preconditioned by

  17. Gamma irradiation, hot water and imazalil treatments on decay organisms and physical quality of stored netted muskmelon fruit

    International Nuclear Information System (INIS)

    Lester, G.

    1989-01-01

    Nonchemical treatments of gamma irradiation (2 Kilograys) and hot water (57°C) and the fungicide imazalil (1000 ppm) were compared with and without shrink-film wrap for effects on decay and physical quality of netted muskmelon fruit stored at 4°C for 0 through 60 days. Gamma irradiation was ineffective in controlling decay and surface molds, and injurious to physical quality by decreasing firmness, increasing fresh weight loss, membrane leakage and vein track browning. Hot water treatment coupled with shrink-film wrap was effective in controlling decay activity and maintaining physical quality up to 20 days storage. Imazalil coupled with shrink-film wrap controlled the incidence and severity of decay and maintained fruit firmness, moisture loss, membrane permeability and vein track browning for almost 60 days storage. (author)

  18. Net CO2 and water exchanges of trees and grasses in a semi-arid region (Gourma, Mali)

    Science.gov (United States)

    Le Dantec, Valérie; Kergoat, Laurent; Timouk, Franck; Hiernaux, Pierre; Mougin, Eric

    2010-05-01

    An improved understanding of plant and soil processes is critical to predict land surface-atmosphere water exchanges, especially in semi-arid environments, where knowledge is still severely lacking. Within the frame of the African Monsoon Multidisciplinary Project (AMMA), eddy covariance and sapflow stations have been installed to document the intensity, the temporal variability and the main drivers of net CO2 fluxes, water fluxes and contribution of the trees to these fluxes in a pastoral Sahelian landscape. Indeed, although the importance of vegetation in the West African monsoon system has long been postulated, extremely few data were available sofar to test and develop land surface models. In particular, data documenting seasonal and inter-annual dynamics of vegetation/atmosphere exchanges did not exist at 15° N in West Africa before AMMA. The site is located in the Gourma, Mali. Vegetation in this area is sparse and mainly composed of annual grasses and forbs, and trees. Vegetation is organized according to soil type and lateral water redistribution, with bare soil with scattered trees on shallow soils and rocky outcrops (35% of the area), annual grasses and scattered trees on sandy soils (65% of the area), and more dense canopies of grasses and trees growing in valley bottoms over clay soil. To quantify tree transpiration in the overall evapotranspiration flux, sapflow measurements, associated to soil moisture measurements, have been conducted on the main tree species (Acacia senegal, A. seyal, A. raddiana, Combretum glutinosum, Balanites aegyptiaca) in a grassland site and in an open forest site, where eddy covariance fluxes measured the total flux. Using this dataset, we have studied the effects of plant diversity on carbon and water fluxes at the foot-print scale and seasonal dynamics of fluxes due to plant phenology and variations of soil water content (SWC). Carbon fluxes were documented as well, over two years. NEE was close to 0 during the dry season

  19. Virtual water content of temperate cereals and maize: Present and potential future patterns

    Science.gov (United States)

    Fader, Marianela; Rost, Stefanie; Müller, Christoph; Bondeau, Alberte; Gerten, Dieter

    2010-04-01

    SummaryKnowledge of the virtual water content (VWC) of crops and especially its possible future developments is helpful for improvements in water productivity and water management, which are necessary at global scale due to rising demand for food, the necessity to ease present and future water scarcity, and the reduction of poverty. Using a dynamic global vegetation and water balance model (LPJmL), this study quantifies the VWC of two of the most important crop types worldwide, temperate cereals and maize, at high spatial resolution (0.5°). We analyzed present conditions (1999-2003) and also for the first time also for scenarios of future climate and increasing atmospheric CO 2 concentrations (2041-2070; HadCM3, ECHAM5 and CCSM3 climate models, A2 emissions scenario). VWC presently differs significantly among regions: highest values are common in large parts of Africa (>2 m 3 kg -1), and lowest values were found e.g. for Central Europe (Europe, South Africa, Argentina, Australia and South East Asia—are projected to become less water efficient (higher VWC) for at least one of the crop types. CO 2 fertilisation was simulated to generally reduce VWC, though realisation of this effect in the field will depend, for example, on the intensity of nutrient management in the future. The potentially adverse future changes in VWC found here pose a challenge to water management efforts and eventually global trade policies.

  20. Uncovering the Green, Blue, and Grey Water Footprint and Virtual Water of Biofuel Production in Brazil: A Nexus Perspective

    Directory of Open Access Journals (Sweden)

    Raul Munoz Castillo

    2017-11-01

    Full Text Available Brazil plays a major role in the global biofuel economy as the world’s second largest producer and consumer and the largest exporter of ethanol. Its demand is expected to significantly increase in coming years, largely driven by national and international carbon mitigation targets. However, biofuel crops require significant amounts of water and land resources that could otherwise be used for the production of food, urban water supply, or energy generation. Given Brazil’s uneven spatial distribution of water resources among regions, a potential expansion of ethanol production will need to take into account regional or local water availability, as an increased water demand for irrigation would put further pressure on already water-scarce regions and compete with other users. By applying an environmentally extended multiregional input-output (MRIO approach, we uncover the scarce water footprint and the interregional virtual water flows associated with sugarcane-derived biofuel production driven by domestic final consumption and international exports in 27 states in Brazil. Our results show that bio-ethanol is responsible for about one third of the total sugarcane water footprint besides sugar and other processed food production. We found that richer states such as São Paulo benefit by accruing a higher share of economic value added from exporting ethanol as part of global value chains while increasing water stress in poorer states through interregional trade. We also found that, in comparison with other crops, sugarcane has a comparative advantage when rainfed while showing a comparative disadvantage as an irrigated crop; a tradeoff to be considered when planning irrigation infrastructure and bioethanol production expansion.

  1. Foodsheds in Virtual Water Flow Networks: A Spectral Graph Theory Approach

    Directory of Open Access Journals (Sweden)

    Nina Kshetry

    2017-06-01

    Full Text Available A foodshed is a geographic area from which a population derives its food supply, but a method to determine boundaries of foodsheds has not been formalized. Drawing on the food–water–energy nexus, we propose a formal network science definition of foodsheds by using data from virtual water flows, i.e., water that is virtually embedded in food. In particular, we use spectral graph partitioning for directed graphs. If foodsheds turn out to be geographically compact, it suggests the food system is local and therefore reduces energy and externality costs of food transport. Using our proposed method we compute foodshed boundaries at the global-scale, and at the national-scale in the case of two of the largest agricultural countries: India and the United States. Based on our determination of foodshed boundaries, we are able to better understand commodity flows and whether foodsheds are contiguous and compact, and other factors that impact environmental sustainability. The formal method we propose may be used more broadly to study commodity flows and their impact on environmental sustainability.

  2. Virtual water maze learning in human increases functional connectivity between posterior hippocampus and dorsal caudate.

    Science.gov (United States)

    Woolley, Daniel G; Mantini, Dante; Coxon, James P; D'Hooge, Rudi; Swinnen, Stephan P; Wenderoth, Nicole

    2015-04-01

    Recent work has demonstrated that functional connectivity between remote brain regions can be modulated by task learning or the performance of an already well-learned task. Here, we investigated the extent to which initial learning and stable performance of a spatial navigation task modulates functional connectivity between subregions of hippocampus and striatum. Subjects actively navigated through a virtual water maze environment and used visual cues to learn the position of a fixed spatial location. Resting-state functional magnetic resonance imaging scans were collected before and after virtual water maze navigation in two scan sessions conducted 1 week apart, with a behavior-only training session in between. There was a large significant reduction in the time taken to intercept the target location during scan session 1 and a small significant reduction during the behavior-only training session. No further reduction was observed during scan session 2. This indicates that scan session 1 represented initial learning and scan session 2 represented stable performance. We observed an increase in functional connectivity between left posterior hippocampus and left dorsal caudate that was specific to scan session 1. Importantly, the magnitude of the increase in functional connectivity was correlated with offline gains in task performance. Our findings suggest cooperative interaction occurs between posterior hippocampus and dorsal caudate during awake rest following the initial phase of spatial navigation learning. Furthermore, we speculate that the increase in functional connectivity observed during awake rest after initial learning might reflect consolidation-related processing. © 2014 Wiley Periodicals, Inc.

  3. Modeling of the chemical stage in water radiolysis using Petri nets

    International Nuclear Information System (INIS)

    Barilla, J; Simr, P; Lokajíček, M; Pisaková, H

    2014-01-01

    The biological effect of ionizing radiation is mediated practically always by the clusters of radicals formed by densely ionizing track ends of primary or secondary particles. In the case of low-LET radiation the direct effect may be practically neglected and the radical clusters meet a DNA molecule always some time after their formation. The corresponding damage effect (formation of DSB) depends then on the evolution running in individual clusters, being influenced by present chemical agents. Two main parallel processes influence then final effect: diffusion of corresponding radical clusters (lowering radical concentrations) and chemical reactions of all chemical substances present in the clusters. The processes running in the corresponding radical clusters will be modeled with the help of continuous Petri net, which enables us to study the concurrent influence of both the processes: lowering concentration of radicals due diffusion and due chemical reactions. The given model may be helpful especially when the effect of radicals on DSB formation (DNA damage) at the presence of different substances influencing radiobiological effect is to be studied

  4. Specific net present value: an improved method for assessing modularisation costs in water services with growing demand.

    Science.gov (United States)

    Maurer, M

    2009-05-01

    A specific net present value (SNPV) approach is introduced as a criterion in economic engineering decisions. The SNPV expresses average costs, including the growth rate and plant utilisation over the planning horizon, factors that are excluded from a standard net present value approach. The use of SNPV favours alternatives that are cheaper per service unit and are therefore closer to the costs that a user has to cover. It also shows that demand growth has a similar influence on average costs as an economy of scale. In a high growth scenario, solutions providing less idle capacity can have higher present value costs and still be economically favourable. The SNPV approach is applied in two examples to calculate acceptable additional costs for modularisation and comparable costs for on-site treatment (OST) as an extreme form of modularisation. The calculations show that: (i) the SNPV approach is suitable for quantifying the comparable costs of an OST system in a different scenario; (ii) small systems with projected high demand growth rates and high real interest rates are the most probable entry market for OST water treatment systems; (iii) operating expenses are currently the main economic weakness of membrane-based wastewater OST systems; and (iv) when high growth in demand is expected, up to 100% can be additionally invested in modularisation and staging the expansion of a treatment plant.

  5. Virtual water content for meat and egg production through livestock farming in Saudi Arabia

    Science.gov (United States)

    Chowdhury, Shakhawat; Ouda, Omar K. M.; Papadopoulou, Maria P.

    2017-12-01

    The concept of virtual water content (VWC) may facilitate an understanding of total water demand for commodity production. The water consumption for livestock production forms a significant fraction of freshwater demand in arid regions, i.e., Saudi Arabia. In this paper, VWC was estimated for different livestocks in the 13 regions of Saudi Arabia. The VWC for camel production was also estimated, which has not been investigated in the previous studies. The overall VWC for livestock in Saudi Arabia was about 10.5 and 8.9 billion m3 in 2006 and 2010, respectively. This study shows the decreasing trend of overall VWC in producing livestock in Saudi Arabia. The VWC were highest in Riyadh followed by Eastern region, Qaseem, Hail, and Makkah with ranges of 3587-4112, 1684-2044, 1007-1331, 644-810, and 504-715 million m3/year, respectively. The results demonstrate that a shift in diet from the high VWC meat to low VWC meat may reduce the overall VWC for livestock production. The findings of this analysis provide an assessment of the quantity and trend of water demand for livestock production in Saudi Arabia, which is useful to assess the development of an information-based agricultural water management strategy.

  6. Net removal of dissolved organic carbon in the anoxic waters of the Black Sea

    NARCIS (Netherlands)

    Margolin, A.R.; Gerringa, L.J.A.; Hansell, D.A.; Rijkenberg, M.J.A.

    2016-01-01

    Dissolved organic carbon (DOC) concentrations in the deep Black Sea are ~2.5 times higher than found in the globalocean. The two major external sources of DOC are rivers and the Sea of Marmara, a transit point for waters from theMediterranean Sea. In addition, expansive phytoplankton blooms

  7. Petri Nets

    Indian Academy of Sciences (India)

    In a computer system, for example, typical discrete events ... This project brought out a series of influential reports on Petri net theory in the mid and late ... Technology became a leading centre for Petri net research and from then on, Petri nets ...

  8. Path Complexity in Virtual Water Maze Navigation: Differential Associations with Age, Sex, and Regional Brain Volume.

    Science.gov (United States)

    Daugherty, Ana M; Yuan, Peng; Dahle, Cheryl L; Bender, Andrew R; Yang, Yiqin; Raz, Naftali

    2015-09-01

    Studies of human navigation in virtual maze environments have consistently linked advanced age with greater distance traveled between the start and the goal and longer duration of the search. Observations of search path geometry suggest that routes taken by older adults may be unnecessarily complex and that excessive path complexity may be an indicator of cognitive difficulties experienced by older navigators. In a sample of healthy adults, we quantify search path complexity in a virtual Morris water maze with a novel method based on fractal dimensionality. In a two-level hierarchical linear model, we estimated improvement in navigation performance across trials by a decline in route length, shortening of search time, and reduction in fractal dimensionality of the path. While replicating commonly reported age and sex differences in time and distance indices, a reduction in fractal dimension of the path accounted for improvement across trials, independent of age or sex. The volumes of brain regions associated with the establishment of cognitive maps (parahippocampal gyrus and hippocampus) were related to path dimensionality, but not to the total distance and time. Thus, fractal dimensionality of a navigational path may present a useful complementary method of quantifying performance in navigation. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. Use of the Budyko Framework to Estimate the Virtual Water Content in Shijiazhuang Plain, North China

    Science.gov (United States)

    Zhang, E.; Yin, X.

    2017-12-01

    One of the most challenging steps in implementing analysis of virtual water content (VWC) of agricultural crops is how to properly assess the volume of consumptive water use (CWU) for crop production. In practice, CWU is considered equivalent to the crop evapotranspiration (ETc). Following the crop coefficient method, ETc can be calculated under standard or non-standard conditions by multiplying the reference evapotranspiration (ET0) by one or a few coefficients. However, when current crop growing conditions deviate from standard conditions, accurately determining the coefficients under non-standard conditions remains to be a complicated process and requires lots of field experimental data. Based on regional surface water-energy balance, this research integrates the Budyko framework into the traditional crop coefficient approach to simplify the coefficients determination. This new method enables us to assess the volume of agricultural VWC only based on some hydrometeorological data and agricultural statistic data in regional scale. To demonstrate the new method, we apply it to the Shijiazhuang Plain, which is an agricultural irrigation area in the North China Plain. The VWC of winter wheat and summer maize is calculated and we further subdivide VWC into blue and green water components. Compared with previous studies in this study area, VWC calculated by the Budyko-based crop coefficient approach uses less data and agrees well with some of the previous research. It shows that this new method may serve as a more convenient tool for assessing VWC.

  10. The spatiotemporal variation analysis of virtual water for agriculture and livestock husbandry: A study for Jilin Province in China.

    Science.gov (United States)

    Ma, Xiaolei; Ma, Yanji

    2017-05-15

    With the rapid development of economic, water crisis is becoming more and more serious and would be an important obstacle to the sustainable development of society. Virtual water theory and its applications in agriculture can provide important strategies for realizing the reasonable utilization and sustainable development of water resources. Using the Penman-Monteith model and Theil index combining the CROPWAT software, this work takes Jilin Province as study area quantifying the virtual water content of agriculture and livestock husbandry and giving a comprehensive evaluation of their spatiotemporal structure evolution. This study aims to help make clear the water consumption of agriculture and livestock husbandry, and offer advice on rational water utilization and agricultural structure adjustment. The results show that the total virtual water (TVW) proportion of agriculture presents a gradual growth trend while that of livestock husbandry reduces during the study period. In space, central Jilin shows the highest virtual water content of agriculture as well as livestock husbandry, the TVW in central Jilin is about 35.8billionm 3 . The TVW of maize is highest among six studied crops, and the cattle shows the highest TVW in the four kinds of animals. The distribution of TVW calculated by us and the distribution of actual water resources have remarkable difference, which leads to the increase of water consumption and cost of agricultural production. Finally, we discuss the driving force of the spatiotemporal variation of the TVW for agriculture and livestock husbandry, and also give some advises for the planting structural adjustment. This work is helpful for the sustainable development of agricultural and livestock husbandry and realizing efficient utilization of water resources. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Intercalibration study. Net of quality control of waters of the Department of Antioquia

    International Nuclear Information System (INIS)

    Parra M, C.M; Mejia Z, G.M.

    1999-01-01

    The norm ISO 5725 has set a series of statistical procedures for the evaluation of results for an intercalibration study which of course is a fundamental support for the setting of a quality control program that must be implement by every laboratory seeking accreditation. In the present paper the implementation of such procedures is shown for an exercise classified to be as of a uniform level. The chosen parameter was suspended solids which is included in the fees of the retributive rates set by the Ministerio del Medio Ambiente in Colombia. The exercise was done by the laboratories that are members of the Analytical Control of Water Web in the Department of Antioquia

  12. Água virtual, escassez e gestão: o Brasil como grande "exportador" de água Virtual water, scarcity and management: Brazil as a large water exporter

    Directory of Open Access Journals (Sweden)

    Roberto Luiz do Carmo

    2007-12-01

    Full Text Available Recentemente, a valoração econômica da água tem sido discutida no cenário político brasileiro. Faz parte dessa discussão a incorporação da água nos produtos que circulam no mercado, especialmente através de commodities, utilizando o conceito de "água virtual". Este trabalho avalia o impacto da utilização do conceito de água virtual no cenário brasileiro, ao mesmo tempo em que discute as decorrências dessa exportação.The economic valuation of water has recently been discussed in the Brazilian political scenario. Incorporation of water in trade and commerce, especially in commodities is part of the proposed discussion , using the "virtual water" concept. In this article we search for the impact that the utilization of the "virtual water" concept may have in the Brazilian scenario and discuss, at the same time, the consequences of this exportation.

  13. The use of process simulation models in virtual commissioning of process automation software in drinking water treatment plants

    NARCIS (Netherlands)

    Worm, G.I.M.; Kelderman, J.P.; Lapikas, T.; Van der Helm, A.W.C.; Van Schagen, K.M.; Rietveld, L.C.

    2012-01-01

    This research deals with the contribution of process simulation models to the factory acceptance test (FAT) of process automation (PA) software of drinking water treatment plants. Two test teams tested the same piece of modified PA-software. One team used an advanced virtual commissioning (AVC)

  14. Organic fertilizer application increases the soil respiration and net ecosystem carbon dioxide absorption of paddy fields under water-saving irrigation.

    Science.gov (United States)

    Yang, Shihong; Xiao, Ya Nan; Xu, Junzeng

    2018-04-01

    Quantifying carbon sequestration in paddy soil is necessary to understand the effect of agricultural practices on carbon cycles. The objective of this study was to assess the effect of organic fertilizer addition (MF) on the soil respiration and net ecosystem carbon dioxide (CO 2 ) absorption of paddy fields under water-saving irrigation (CI) in the Taihu Lake Region of China during the 2014 and 2015 rice-growing seasons. Compared with the traditional fertilizer and water management (FC), the joint regulation of CI and MF (CM) significantly increased the rice yields and irrigation water use efficiencies of paddy fields by 4.02~5.08 and 83.54~109.97% (p < 0.05). The effects of organic fertilizer addition on soil respiration and net ecosystem CO 2 absorption rates showed inter-annual differences. CM paddy fields showed a higher soil respiration and net CO 2 absorption rates during some periods of the rice growth stage in the first year and during most periods of the rice growth stage in the second year. These fields also had significantly higher total CO 2 emission through soil respiration (total R soil ) and total net CO 2 absorption compared with FC paddy fields (p < 0.05). The total R soil and net ecosystem CO 2 absorption of CM paddy fields were 67.39~91.55 and 129.41~113.75 mol m -2 , which were 27.66~135.52 and 12.96~31.66% higher than those of FC paddy fields. The interaction between water and fertilizer management had significant effects on total net ecosystem CO 2 absorption. The frequent alternate wet-dry cycles of CI paddy fields increased the soil respiration and reduced the net CO 2 absorption. Organic fertilizer promoted the soil respiration of paddy soil but also increased its net CO 2 absorption and organic carbon content. Therefore, the joint regulation of water-saving irrigation and organic fertilizer is an effective measure for maintaining yield, increasing irrigation water use efficiency, mitigating CO 2 emission, and promoting paddy

  15. The influence of CO2 enrichment on net photosynthesis of seagrass Zostera marina in a brackish water environment

    Directory of Open Access Journals (Sweden)

    Liina Pajusalu

    2016-11-01

    Full Text Available Seagrasses are distributed across the globe and their communities may play key roles in the coastal ecosystems. Seagrass meadows are expected to benefit from the increased carbon availability which might be used in photosynthesis in a future high CO2 world. The main aim of this study was to examine the effect of elevated pCO2 on the net photosynthesis of seagrass Zostera marina in a brackish water environment. The short-term mesocosm experiments were conducted in Kõiguste Bay (northern part of Gulf of Riga, the Baltic Sea in June-July 2013 and 2014. As the levels of pCO2 naturally range from ca. 150 μatm to well above 1000 μatm under summer conditions in Kõiguste Bay we chose to operate in mesocosms with the pCO2 levels of ca. 2000, ca. 1000 and ca. 200 μatm. Additionally, in 2014 the photosynthesis of Z. marina was measured outside of the mesocosm in the natural conditions. In the shallow coastal Baltic Sea seagrass Z. marina lives in a highly variable environment due to seasonality and rapid changes in meteorological conditions. This was demonstrated by the remarkable differences in water temperatures between experimental years of ca. 8°C. Thus, the current study also investigated the effect of elevated pCO2 in combination with short-term natural fluctuations of environmental factors, i.e. temperature and PAR on the photosynthesis of Z. marina. Our results show that elevated pCO2 alone did not enhance the photosynthesis of the seagrass. The photosynthetic response of Z. marina to CO2 enrichment was affected by changes in water temperature and light availability.

  16. The effect of inter-annual variability of consumption, production, trade and climate on crop-related green and blue water footprints and inter-regional virtual water trade: A study for China (1978-2008).

    Science.gov (United States)

    Zhuo, La; Mekonnen, Mesfin M; Hoekstra, Arjen Y

    2016-05-01

    Previous studies into the relation between human consumption and indirect water resources use have unveiled the remote connections in virtual water (VW) trade networks, which show how communities externalize their water footprint (WF) to places far beyond their own region, but little has been done to understand variability in time. This study quantifies the effect of inter-annual variability of consumption, production, trade and climate on WF and VW trade, using China over the period 1978-2008 as a case study. Evapotranspiration, crop yields and green and blue WFs of crops are estimated at a 5 × 5 arc-minute resolution for 22 crops, for each year in the study period, thus accounting for climate variability. The results show that crop yield improvements during the study period helped to reduce the national average WF of crop consumption per capita by 23%, with a decreasing contribution to the total from cereals and increasing contribution from oil crops. The total consumptive WFs of national crop consumption and crop production, however, grew by 6% and 7%, respectively. By 2008, 28% of total water consumption in crop fields in China served the production of crops for export to other regions and, on average, 35% of the crop-related WF of a Chinese consumer was outside its own province. Historically, the net VW within China was from the water-rich South to the water-scarce North, but intensifying North-to-South crop trade reversed the net VW flow since 2000, which amounted 6% of North's WF of crop production in 2008. South China thus gradually became dependent on food supply from the water-scarce North. Besides, during the whole study period, China's domestic inter-regional VW flows went dominantly from areas with a relatively large to areas with a relatively small blue WF per unit of crop, which in 2008 resulted in a trade-related blue water loss of 7% of the national total blue WF of crop production. The case of China shows that domestic trade, as governed by

  17. Application of water footprint combined with a unified virtual crop pattern to evaluate crop water productivity in grain production in China.

    Science.gov (United States)

    Wang, Y B; Wu, P T; Engel, B A; Sun, S K

    2014-11-01

    Water shortages are detrimental to China's grain production while food production consumes a great deal of water causing water crises and ecological impacts. Increasing crop water productivity (CWP) is critical, so China is devoting significant resources to develop water-saving agricultural systems based on crop planning and agricultural water conservation planning. A comprehensive CWP index is necessary for such planning. Existing indices such as water use efficiency (WUE) and irrigation efficiency (IE) have limitations and are not suitable for the comprehensive evaluation of CWP. The water footprint (WF) index, calculated using effective precipitation and local water use, has advantages for CWP evaluation. Due to regional differences in crop patterns making the CWP difficult to compare directly across different regions, a unified virtual crop pattern is needed to calculate the WF. This project calculated and compared the WF of each grain crop and the integrated WFs of grain products with actual and virtual crop patterns in different regions of China for 2010. The results showed that there were significant differences for the WF among different crops in the same area or among different areas for the same crop. Rice had the highest WF at 1.39 m(3)/kg, while corn had the lowest at 0.91 m(3)/kg among the main grain crops. The WF of grain products was 1.25 m(3)/kg in China. Crop patterns had an important impact on WF of grain products because significant differences in WF were found between actual and virtual crop patterns in each region. The CWP level can be determined based on the WF of a virtual crop pattern, thereby helping optimize spatial distribution of crops and develop agricultural water savings to increase CWP. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Seasonal trends of light-saturated net photosynthesis and stomatal conductance of loblolly pine trees grown in contrasting environments of nutrition, water and carbon dioxide

    Science.gov (United States)

    Ramesh Murthy; Stanley J. Zarnoch; P.M. Dougherty

    1997-01-01

    Repeated measures analysis was used to evaluate the effect of long-term CO2 enhancement on seasonal trends of light-saturated rates of net photosynthesis (Asat) and stomatal conductance to water vapour (gsat) of 9-year-old loblolly pine (Pinus taeda L.; trees grown in a 2x2...

  19. Simulation of water flow in fractured porous medium by using discretized virtual internal bond

    Science.gov (United States)

    Peng, Shujun; Zhang, Zhennan; Li, Chunfang; He, Guofu; Miao, Guoqing

    2017-12-01

    The discretized virtual internal bond (DVIB) is adopted to simulate the water flow in fractured porous medium. The intact porous medium is permeable because it contains numerous micro cracks and pores. These micro discontinuities construct a fluid channel network. The representative volume of this fluid channel network is modeled as a lattice bond cell with finite number of bonds in statistical sense. Each bond serves as a fluid channel. In fractured porous medium, many bond cells are cut by macro fractures. The conductivity of the fracture facet in a bond cell is taken over by the bonds parallel to the flow direction. The equivalent permeability and volumetric storage coefficient of a micro bond are calibrated based on the ideal bond cell conception, which makes it unnecessary to consider the detailed geometry of a specific element. Such parameter calibration method is flexible and applicable to any type of element. The accuracy check results suggest this method has a satisfying accuracy in both the steady and transient flow simulation. To simulate the massive fractures in rockmass, the bond cells intersected by fracture are assigned aperture values, which are assumed random numbers following a certain distribution law. By this method, any number of fractures can be implicitly incorporated into the background mesh, avoiding the setup of fracture element and mesh modification. The fracture aperture heterogeneity is well represented by this means. The simulation examples suggest that the present method is a feasible, simple and efficient approach to the numerical simulation of water flow in fractured porous medium.

  20. Characterization of the phantom material Virtual WaterTM in high-energy photon and electron beams

    International Nuclear Information System (INIS)

    McEwen, M.R.; Niven, D.

    2006-01-01

    The material Virtual Water TM has been characterized in photon and electron beams. Range-scaling factors and fluence correction factors were obtained, the latter with an uncertainty of around 0.2%. This level of uncertainty means that it may be possible to perform dosimetry in a solid phantom with an accuracy approaching that of measurements in water. Two formulations of Virtual Water TM were investigated with nominally the same elemental composition but differing densities. For photon beams neither formulation showed exact water equivalence--the water/Virtual Water TM dose ratio varied with the depth of measurement with a difference of over 1% at 10 cm depth. However, by using a density (range) scaling factor very good agreement ( TM at all depths was obtained. In the case of electron beams a range-scaling factor was also required to match the shapes of the depth dose curves in water and Virtual Wate TM . However, there remained a difference in the measured fluence in the two phantoms after this scaling factor had been applied. For measurements around the peak of the depth-dose curve and the reference depth this difference showed some small energy dependence but was in the range 0.1%-0.4%. Perturbation measurements have indicated that small slabs of material upstream of a detector have a small (<0.1% effect) on the chamber reading but material behind the detector can have a larger effect. This has consequences for the design of experiments and in the comparison of measurements and Monte Carlo-derived values

  1. Net Neutrality

    DEFF Research Database (Denmark)

    Savin, Andrej

    2017-01-01

    Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else.......Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else....

  2. Modeling Water-Surface Elevations and Virtual Shorelines for the Colorado River in Grand Canyon, Arizona

    Science.gov (United States)

    Magirl, Christopher S.; Breedlove, Michael J.; Webb, Robert H.; Griffiths, Peter G.

    2008-01-01

    Using widely-available software intended for modeling rivers, a new one-dimensional hydraulic model was developed for the Colorado River through Grand Canyon from Lees Ferry to Diamond Creek. Solving one-dimensional equations of energy and continuity, the model predicts stage for a known steady-state discharge at specific locations, or cross sections, along the river corridor. This model uses 2,680 cross sections built with high-resolution digital topography of ground locations away from the river flowing at a discharge of 227 m3/s; synthetic bathymetry was created for topography submerged below the 227 m3/s water surface. The synthetic bathymetry was created by adjusting the water depth at each cross section up or down until the model?s predicted water-surface elevation closely matched a known water surface. This approach is unorthodox and offers a technique to construct one-dimensional hydraulic models of bedrock-controlled rivers where bathymetric data have not been collected. An analysis of this modeling approach shows that while effective in enabling a useful model, the synthetic bathymetry can differ from the actual bathymetry. The known water-surface profile was measured using elevation data collected in 2000 and 2002, and the model can simulate discharges up to 5,900 m3/s. In addition to the hydraulic model, GIS-based techniques were used to estimate virtual shorelines and construct inundation maps. The error of the hydraulic model in predicting stage is within 0.4 m for discharges less than 1,300 m3/s. Between 1,300-2,500 m3/s, the model accuracy is about 1.0 m, and for discharges between 2,500-5,900 m3/s, the model accuracy is on the order of 1.5 m. In the absence of large floods on the flow-regulated Colorado River in Grand Canyon, the new hydraulic model and the accompanying inundation maps are a useful resource for researchers interested in water depths, shorelines, and stage-discharge curves for flows within the river corridor with 2002 topographic

  3. A process to estimate net infiltration using a site-scale water-budget approach, Rainier Mesa, Nevada National Security Site, Nevada, 2002–05

    Science.gov (United States)

    Smith, David W.; Moreo, Michael T.; Garcia, C. Amanda; Halford, Keith J.; Fenelon, Joseph M.

    2017-08-29

    This report documents a process used to estimate net infiltration from precipitation, evapotranspiration (ET), and soil data acquired at two sites on Rainier Mesa. Rainier Mesa is a groundwater recharge area within the Nevada National Security Site where recharged water flows through bedrock fractures to a deep (450 meters) water table. The U.S. Geological Survey operated two ET stations on Rainier Mesa from 2002 to 2005 at sites characterized by pinyon-juniper and scrub-brush vegetative cover. Precipitation and ET data were corrected to remove measurement biases and gap-filled to develop continuous datasets. Net infiltration (percolation below the root zone) and changes in root-zone water storage were estimated using a monthly water-balance model.Site-scale water-budget results indicate that the heavily-fractured welded-tuff bedrock underlying thin (water source for vegetation during dry periods. Annual precipitation during the study period ranged from fourth lowest (182 millimeters [mm]) to second highest (708 mm) on record (record = 55 years). Annual ET exceeded precipitation during dry years, indicating that the fractured-bedrock reservoir capacity is sufficient to meet atmospheric-evaporative demands and to sustain vegetation through extended dry periods. Net infiltration (82 mm) was simulated during the wet year after the reservoir was rapidly filled to capacity. These results support previous conclusions that preferential fracture flow was induced, resulting in an episodic recharge pulse that was detected in nearby monitoring wells. The occurrence of net infiltration only during the wet year is consistent with detections of water-level rises in nearby monitoring wells that occur only following wet years.

  4. Sex differences in a virtual water maze: an eye tracking and pupillometry study.

    Science.gov (United States)

    Mueller, Sven C; Jackson, Carl P T; Skelton, Ron W

    2008-11-21

    Sex differences in human spatial navigation are well known. However, the exact strategies that males and females employ in order to navigate successfully around the environment are unclear. While some researchers propose that males prefer environment-centred (allocentric) and females prefer self-centred (egocentric) navigation, these findings have proved difficult to replicate. In the present study we examined eye movements and physiological measures of memory (pupillometry) in order to compare visual scanning of spatial orientation using a human virtual analogue of the Morris Water Maze task. Twelve women and twelve men (average age=24 years) were trained on a visible platform and had to locate an invisible platform over a series of trials. On all but the first trial, participants' eye movements were recorded for 3s and they were asked to orient themselves in the environment. While the behavioural data replicated previous findings of improved spatial performance for males relative to females, distinct sex differences in eye movements were found. Males tended to explore consistently more space early on while females demonstrated initially longer fixation durations and increases in pupil diameter usually associated with memory processing. The eye movement data provides novel insight into differences in navigational strategies between the sexes.

  5. Acute stress switches spatial navigation strategy from egocentric to allocentric in a virtual Morris water maze.

    Science.gov (United States)

    van Gerven, Dustin J H; Ferguson, Thomas; Skelton, Ronald W

    2016-07-01

    Stress and stress hormones are known to influence the function of the hippocampus, a brain structure critical for cognitive-map-based, allocentric spatial navigation. The caudate nucleus, a brain structure critical for stimulus-response-based, egocentric navigation, is not as sensitive to stress. Evidence for this comes from rodent studies, which show that acute stress or stress hormones impair allocentric, but not egocentric navigation. However, there have been few studies investigating the effect of acute stress on human spatial navigation, and the results of these have been equivocal. To date, no study has investigated whether acute stress can shift human navigational strategy selection between allocentric and egocentric navigation. The present study investigated this question by exposing participants to an acute psychological stressor (the Paced Auditory Serial Addition Task, PASAT), before testing navigational strategy selection in the Dual-Strategy Maze, a modified virtual Morris water maze. In the Dual-Strategy maze, participants can chose to navigate using a constellation of extra-maze cues (allocentrically) or using a single cue proximal to the goal platform (egocentrically). Surprisingly, PASAT stress biased participants to solve the maze allocentrically significantly more, rather than less, often. These findings have implications for understanding the effects of acute stress on cognitive function in general, and the function of the hippocampus in particular. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Contributions of sex, testosterone, and androgen receptor CAG repeat number to virtual Morris water maze performance.

    Science.gov (United States)

    Nowak, Nicole T; Diamond, Michael P; Land, Susan J; Moffat, Scott D

    2014-03-01

    The possibility that androgens contribute to the male advantage typically found on measures of spatial cognition has been investigated using a variety of approaches. To date, evidence to support the notion that androgens affect spatial cognition in healthy young adults is somewhat equivocal. The present study sought to clarify the association between testosterone (T) and spatial performance by extending measurements of androgenicity to include both measures of circulating T as well as an androgen receptor-specific genetic marker. The aims of this study were to assess the contributions of sex, T, and androgen receptor CAG repeat number (CAGr) on virtual Morris water task (vMWT) performance in a group of healthy young men and women. The hypothesis that men would outperform women on vMWT outcomes was supported. Results indicate that CAGr may interact with T to impact navigation performance and suggest that consideration of androgen receptor sensitivity is an important consideration in evaluating hormone-behavior relationships. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Cognitive correlates of spatial navigation: Associations between executive functioning and the virtual Morris Water Task.

    Science.gov (United States)

    Korthauer, L E; Nowak, N T; Frahmand, M; Driscoll, I

    2017-01-15

    Although effective spatial navigation requires memory for objects and locations, navigating a novel environment may also require considerable executive resources. The present study investigated associations between performance on the virtual Morris Water Task (vMWT), an analog version of a nonhuman spatial navigation task, and neuropsychological tests of executive functioning and spatial performance in 75 healthy young adults. More effective vMWT performance (e.g., lower latency and distance to reach hidden platform, greater distance in goal quadrant on a probe trial, fewer path intersections) was associated with better verbal fluency, set switching, response inhibition, and ability to mentally rotate objects. Findings also support a male advantage in spatial navigation, with sex moderating several associations between vMWT performance and executive abilities. Overall, we report a robust relationship between executive functioning and navigational skill, with some evidence that men and women may differentially recruit cognitive abilities when navigating a novel environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Ageing and spatial reversal learning in humans: findings from a virtual water maze.

    Science.gov (United States)

    Schoenfeld, R; Foreman, N; Leplow, B

    2014-08-15

    Deterioration in spatial memory with normal ageing is well accepted. Animal research has shown spatial reversal learning to be most vulnerable to pathological changes in the brain, but this has never been tested in humans. We studied ninety participants (52% females, 20-80 yrs) in a virtual water maze with a reversal learning procedure. Neuropsychological functioning, mood and personality were assessed to control moderator effects. For data analysis, participants were subdivided post hoc into groups aged 20-24, 25-34, 35-44, 45-64 and 65-80 yrs. Initial spatial learning occurred in all age groups but 65-80-yrs-olds never reached the level of younger participants. When tested for delayed recall of spatial memory, younger people frequented the target area but those over 65 yrs did not. In spatial reversal learning, age groups over 45 yrs were deficient and the 65-80-yrs-olds showed no evidence of reversal. Spatial measures were associated with neuropsychological functioning. Extraversion and measures of depression moderated the age effect on the learning index with older introverted and non-depressed individuals showing better results. Measures of anxiety moderated the age effect on reversal learning with older people having higher anxiety scores showing a preserved reversal learning capability. Results confirmed age to be a major factor in spatial tasks but further showed neuropsychological functioning, psycho-affective determinants and personality traits to be significant predictors of individual differences. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Selecting an optimal number of binding site waters to improve virtual screening enrichments against the adenosine A2A receptor.

    Science.gov (United States)

    Lenselink, Eelke B; Beuming, Thijs; Sherman, Woody; van Vlijmen, Herman W T; IJzerman, Adriaan P

    2014-06-23

    A major challenge in structure-based virtual screening (VS) involves the treatment of explicit water molecules during docking in order to improve the enrichment of active compounds over decoys. Here we have investigated this in the context of the adenosine A2A receptor, where water molecules have previously been shown to be important for achieving high enrichment rates with docking, and where the positions of some binding site waters are known from a high-resolution crystal structure. The effect of these waters (both their presence and orientations) on VS enrichment was assessed using a carefully curated set of 299 high affinity A2A antagonists and 17,337 decoys. We show that including certain crystal waters greatly improves VS enrichment and that optimization of water hydrogen positions is needed in order to achieve the best results. We also show that waters derived from a molecular dynamics simulation - without any knowledge of crystallographic waters - can improve enrichments to a similar degree as the crystallographic waters, which makes this strategy applicable to structures without experimental knowledge of water positions. Finally, we used decision trees to select an ensemble of structures with different water molecule positions and orientations that outperforms any single structure with water molecules. The approach presented here is validated against independent test sets of A2A receptor antagonists and decoys from the literature. In general, this water optimization strategy could be applied to any target with waters-mediated protein-ligand interactions.

  10. Going against the flow: a critical analysis of inter-state virtual water trade in the context of India's national river linking programme

    NARCIS (Netherlands)

    Verma, Shilp; Kampman, Doeke A.; van der Zaag, Pieter; Hoekstra, Arjen Ysbert

    2009-01-01

    Virtual water trade has been promoted as a tool to address national and regional water scarcity. In the context of international (food) trade, this concept has been applied with a view to optimize the flow of commodities considering the water endowments of nations. The concept states that water rich

  11. WATER QUALITY AND ITS EFFECT ON GROWTH AND SURVIVAL RATE OF LOBSTER REARED IN FLOATING NET CAGE IN EKAS BAY, WEST NUSA TENGGARA PROVINCE

    Directory of Open Access Journals (Sweden)

    Muhammad Junaidi

    2015-02-01

    Full Text Available ABSTRACT The development of lobster farming in floating net cage in Ekas Bay caused an environmental degradation such as decrease water quality due to some aquaculture wastes. The purposes of this study were to determine the status of water quality and their effect on growth and survival rate of lobster reared in floating net cages (FNC in the Ekas Bay, West Nusa Tenggara Province. Water sample collection and handling referred to the APHA (1992. Analyses of water quality data were conducted using Principal Component Analysis. Determination of the water quality status of Ekas Bay was performed with STORET system. Multivariate analyses were used to determine the relationship between water quality, growth, and survival rate of lobster reared in FNC. Results showed that Ekas Bay water quality status was categorized in class C (medium contaminated, which exceeded some quality standard parameters such as ammonia (0.3 mg/l, nitrate (0.008 mg/l, and phosphate (0.015 mg/l. During lobster farming activities feeding with trash fish for 270 days, we obtained daily growth rate of  0.74% (lower than normal growth rate of 0.86%, survival rate of 66% (lower than normal survival rate of 86.7%, and feed conversion ratio of 11.15. Ammonia was found as a dominant factor reducing growth  and survival rate of lobster reared in FNC. Keywords: water quality, lobsters, growth, survival, Ekas Bay

  12. Petri Nets

    Indian Academy of Sciences (India)

    GENERAL I ARTICLE ... In Part 1 of this two-part article, we have seen im- ..... mable logic controller and VLSI arrays, office automation systems, workflow management systems, ... complex discrete event and real-time systems; and Petri nets.

  13. Seasonal and Topographic Variation in Net Primary Productivity and Water Use Efficiency in a Southwest Sky Island Fores

    Science.gov (United States)

    Murphy, P.; Minor, R. L.; Sanchez-Canete, E. P.; Potts, D. L.; Barron-Gafford, G.

    2016-12-01

    Western North American Forests represent an uncertain sink for atmospheric carbon. While understanding of the physical drivers of productivity in these forests has grown in the last decade, the relative influence of topographic position in the complex terrain of montane systems remains understudied. The high-latitude mixed conifer forest ecosystems of the southern Arizona Madrean Sky Islands are characterized by low precipitation, high annual variation in temperature, and heterogeneous topography. Eddy covariance measurements these forests show distinct seasonal trends due to temperature and bi-modal precipitation patterns, but these measurements are unable to resolve potential differences in physiological function on opposing north and south aspects within the footprint of the tower. Most of the year, north aspects receive less energy input due to the oblique angle of incoming solar radiation, leading to a divergence in soil moistures and temperatures. However, overall movement of energy and material is much higher on these north aspects on an annual basis. The implications of these differences for net primary productivity (NPP) and water use efficiency (WUE) are poorly addressed in the literature. We evaluated the relative control that topography has on the physical environment (soil moisture and temperature) and how these factors affect water stress, NPP, and WUE. We combined leaf-level measurements of photosynthesis and transpiration with other physiological and meteorological measurements to determine how the dominant vegetation functions as a result of microclimatic conditions. Initial results from the spring and summer measurement periods suggest topographical differences in microclimate, resulting in differences in NPP in the spring, but not the summer. Also, each of the three species on the same aspect responded differently to the same microclimatic conditions, underscoring interspecific variation at the site. How might these patterns change throughout an

  14. Blanket testing in NET

    International Nuclear Information System (INIS)

    Chazalon, M.; Daenner, W.; Libin, B.

    1989-01-01

    The testing stages in NET for the performance assessment of the various breeding blanket concepts developed at the present time in Europe for DEMO (LiPb and ceramic blankets) and the requirements upon NET to perform these tests are reviewed. Typical locations available in NET for blanket testing are the central outboard segments and the horizontal ports of in-vessel sectors. These test positions will be connectable with external test loops. The number of test loops (helium, water, liquid metal) will be such that each major class of blankets can be tested in NET. The test positions, the boundary conditions and the external test loops are identified and the requirements for test blankets are summarized (author). 6

  15. Effects of Biochar on the Net Greenhouse Gas Emissions under Continuous Flooding and Water-Saving Irrigation Conditions in Paddy Soils

    Directory of Open Access Journals (Sweden)

    Le Qi

    2018-05-01

    Full Text Available In this study, we investigated the greenhouse gas emission under different application of biochar in the conditions of continuous flooding and water-saving irrigation in paddy fields, whereas, plant and soil carbon sequestration were considered in the calculation of net greenhouse gas emissions. The emission rates of methane (CH4, carbon dioxide (CO2, and nitrous oxide (N2O gases were simultaneously monitored once every 7–10 days using the closed-chamber method. As a whole, the net greenhouse gas emission in the water-saving irrigation was more than that of the continuous flooding irrigation conditions. Compared with the water-saving irrigation, the continuous flooding irrigation significantly increased the CH4 in the control (CK and chemical fertilizer treatments (NPK. The CO2 emissions increased in each treatment of the water-saving irrigation condition, especially in the chemical fertilizer treatments (NPKFW. Similarly, the soil N2O emission was very sensitive to the water-saving irrigation condition. An interesting finding is that the biochar application in soils cut down the soil N2O emission more significantly than NPKFW in the water-saving irrigation condition while the effect of biochar increased under the continuous flooding irrigation condition.

  16. Analyses of impacts of China's international trade on its water resources and uses

    Science.gov (United States)

    Zhang, Z. Y.; Yang, H.; Shi, M. J.; Zehnder, A. J. B.; Abbaspour, K. C.

    2011-04-01

    This study provides an insight into the impact of China's international trade of goods and services on its water resources and uses. Virtual water flows associated with China's international trade are quantified in an input-output framework. The analysis is scaled down to the sectoral and provincial levels to trace the origins and destinations of virtual water flows associated with the international trade. The results reveal that China is a net virtual water exporter of 4.7 × 1010 m3 year-1, accounting for 2.1% of its total water resources and 8.9% of the total water use. Water scarce regions tend to have higher percentages of virtual water export relative to their water resources and water uses. In the water scarce Huang-Huai-Hai region, the net virtual water export accounts for 7.9% of the region's water resources and 11.2% of its water uses. For individual sectors, major net virtual water exporters are those where agriculture provides raw materials in the initial process of the production chain and/or pollution intensity is high. The results suggest that China's economic gains from being a world "manufacture factory" have come at a high cost to its water resources and through pollution to its environment.

  17. Africa-wide monitoring of small surface water bodies using multisource satellite data: a monitoring system for FEWS NET: chapter 5

    Science.gov (United States)

    Velpuri, Naga Manohar; Senay, Gabriel B.; Rowland, James; Verdin, James P.; Alemu, Henok; Melesse, Assefa M.; Abtew, Wossenu; Setegn, Shimelis G.

    2014-01-01

    Continental Africa has the highest volume of water stored in wetlands, large lakes, reservoirs, and rivers, yet it suffers from problems such as water availability and access. With climate change intensifying the hydrologic cycle and altering the distribution and frequency of rainfall, the problem of water availability and access will increase further. Famine Early Warning Systems Network (FEWS NET) funded by the United States Agency for International Development (USAID) has initiated a large-scale project to monitor small to medium surface water points in Africa. Under this project, multisource satellite data and hydrologic modeling techniques are integrated to monitor several hundreds of small to medium surface water points in Africa. This approach has been already tested to operationally monitor 41 water points in East Africa. The validation of modeled scaled depths with field-installed gauge data demonstrated the ability of the model to capture both the spatial patterns and seasonal variations. Modeled scaled estimates captured up to 60 % of the observed gauge variability with a mean root-mean-square error (RMSE) of 22 %. The data on relative water level, precipitation, and evapotranspiration (ETo) for water points in East and West Africa were modeled since 1998 and current information is being made available in near-real time. This chapter presents the approach, results from the East African study, and the first phase of expansion activities in the West Africa region. The water point monitoring network will be further expanded to cover much of sub-Saharan Africa. The goal of this study is to provide timely information on the water availability that would support already established FEWS NET activities in Africa. This chapter also presents the potential improvements in modeling approach to be implemented during future expansion in Africa.

  18. RESTful NET

    CERN Document Server

    Flanders, Jon

    2008-01-01

    RESTful .NET is the first book that teaches Windows developers to build RESTful web services using the latest Microsoft tools. Written by Windows Communication Foundation (WFC) expert Jon Flanders, this hands-on tutorial demonstrates how you can use WCF and other components of the .NET 3.5 Framework to build, deploy and use REST-based web services in a variety of application scenarios. RESTful architecture offers a simpler approach to building web services than SOAP, SOA, and the cumbersome WS- stack. And WCF has proven to be a flexible technology for building distributed systems not necessa

  19. Improved netting

    International Nuclear Information System (INIS)

    Bramley, A.; Clabburn, R.J.T.

    1976-01-01

    A method is described for producing netting composed of longitudinal and transverse threads of irradiation cross linked thermoplastic material, the threads being joined together at their crossings by moulded masses of cross linked thermoplastic material. The thread may be formed of polyethylene filaments, subjected to a radiation dose of 15 to 25 MR. The moulding can be conducted at 245 0 to 260 0 C or higher. The product is claimed to be an improved quality of netting, with bonds of increased strength between crossing threads. (U.K.)

  20. Horizontal ichthyoplankton tow-net system with unobstructed net opening

    Science.gov (United States)

    Nester, Robert T.

    1987-01-01

    The larval fish sampler described here consists of a modified bridle, frame, and net system with an obstruction-free net opening and is small enough for use on boats 10 m or less in length. The tow net features a square net frame attached to a 0.5-m-diameter cylinder-on-cone plankton net with a bridle designed to eliminate all obstructions forward of the net opening, significantly reducing currents and vibrations in the water directly preceding the net. This system was effective in collecting larvae representing more than 25 species of fish at sampling depths ranging from surface to 10 m and could easily be used at greater depths.

  1. Modeling the future evolution of the virtual water trade network: A combination of network and gravity models

    Science.gov (United States)

    Sartori, Martina; Schiavo, Stefano; Fracasso, Andrea; Riccaboni, Massimo

    2017-12-01

    The paper investigates how the topological features of the virtual water (VW) network and the size of the associated VW flows are likely to change over time, under different socio-economic and climate scenarios. We combine two alternative models of network formation -a stochastic and a fitness model, used to describe the structure of VW flows- with a gravity model of trade to predict the intensity of each bilateral flow. This combined approach is superior to existing methodologies in its ability to replicate the observed features of VW trade. The insights from the models are used to forecast future VW flows in 2020 and 2050, under different climatic scenarios, and compare them with future water availability. Results suggest that the current trend of VW exports is not sustainable for all countries. Moreover, our approach highlights that some VW importers might be exposed to "imported water stress" as they rely heavily on imports from countries whose water use is unsustainable.

  2. Petri Nets

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 9. Petri Nets - Applications. Y Narahari. General Article Volume 4 Issue 9 September 1999 pp 44-52 ... Author Affiliations. Y Narahari1. Department of Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India.

  3. Net Gain

    International Development Research Centre (IDRC) Digital Library (Canada)

    Describing the effect of tax incentives for import, production, and sale of nets and insecticides; and ..... So far, China is the only country where a system for the routine treatment of ...... 1993), and the trials in Ecuador and Peru (Kroeger et al.

  4. Coupled eco-hydrology and biogeochemistry algorithms enable the simulation of water table depth effects on boreal peatland net CO2 exchange

    Science.gov (United States)

    Mezbahuddin, Mohammad; Grant, Robert F.; Flanagan, Lawrence B.

    2017-12-01

    Water table depth (WTD) effects on net ecosystem CO2 exchange of boreal peatlands are largely mediated by hydrological effects on peat biogeochemistry and the ecophysiology of peatland vegetation. The lack of representation of these effects in carbon models currently limits our predictive capacity for changes in boreal peatland carbon deposits under potential future drier and warmer climates. We examined whether a process-level coupling of a prognostic WTD with (1) oxygen transport, which controls energy yields from microbial and root oxidation-reduction reactions, and (2) vascular and nonvascular plant water relations could explain mechanisms that control variations in net CO2 exchange of a boreal fen under contrasting WTD conditions, i.e., shallow vs. deep WTD. Such coupling of eco-hydrology and biogeochemistry algorithms in a process-based ecosystem model, ecosys, was tested against net ecosystem CO2 exchange measurements in a western Canadian boreal fen peatland over a period of drier-weather-driven gradual WTD drawdown. A May-October WTD drawdown of ˜ 0.25 m from 2004 to 2009 hastened oxygen transport to microbial and root surfaces, enabling greater microbial and root energy yields and peat and litter decomposition, which raised modeled ecosystem respiration (Re) by 0.26 µmol CO2 m-2 s-1 per 0.1 m of WTD drawdown. It also augmented nutrient mineralization, and hence root nutrient availability and uptake, which resulted in improved leaf nutrient (nitrogen) status that facilitated carboxylation and raised modeled vascular gross primary productivity (GPP) and plant growth. The increase in modeled vascular GPP exceeded declines in modeled nonvascular (moss) GPP due to greater shading from increased vascular plant growth and moss drying from near-surface peat desiccation, thereby causing a net increase in modeled growing season GPP by 0.39 µmol CO2 m-2 s-1 per 0.1 m of WTD drawdown. Similar increases in GPP and Re caused no significant WTD effects on modeled

  5. Coupled eco-hydrology and biogeochemistry algorithms enable the simulation of water table depth effects on boreal peatland net CO2 exchange

    Directory of Open Access Journals (Sweden)

    M. Mezbahuddin

    2017-12-01

    Full Text Available Water table depth (WTD effects on net ecosystem CO2 exchange of boreal peatlands are largely mediated by hydrological effects on peat biogeochemistry and the ecophysiology of peatland vegetation. The lack of representation of these effects in carbon models currently limits our predictive capacity for changes in boreal peatland carbon deposits under potential future drier and warmer climates. We examined whether a process-level coupling of a prognostic WTD with (1 oxygen transport, which controls energy yields from microbial and root oxidation–reduction reactions, and (2 vascular and nonvascular plant water relations could explain mechanisms that control variations in net CO2 exchange of a boreal fen under contrasting WTD conditions, i.e., shallow vs. deep WTD. Such coupling of eco-hydrology and biogeochemistry algorithms in a process-based ecosystem model, ecosys, was tested against net ecosystem CO2 exchange measurements in a western Canadian boreal fen peatland over a period of drier-weather-driven gradual WTD drawdown. A May–October WTD drawdown of  ∼  0.25 m from 2004 to 2009 hastened oxygen transport to microbial and root surfaces, enabling greater microbial and root energy yields and peat and litter decomposition, which raised modeled ecosystem respiration (Re by 0.26 µmol CO2 m−2 s−1 per 0.1 m of WTD drawdown. It also augmented nutrient mineralization, and hence root nutrient availability and uptake, which resulted in improved leaf nutrient (nitrogen status that facilitated carboxylation and raised modeled vascular gross primary productivity (GPP and plant growth. The increase in modeled vascular GPP exceeded declines in modeled nonvascular (moss GPP due to greater shading from increased vascular plant growth and moss drying from near-surface peat desiccation, thereby causing a net increase in modeled growing season GPP by 0.39 µmol CO2 m−2 s−1 per 0.1 m of WTD drawdown. Similar increases in

  6. Net Locality

    DEFF Research Database (Denmark)

    de Souza e Silva, Adriana Araujo; Gordon, Eric

    Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps......, to location-based social networks and games, such as Foursquare and facebook. Warns of the threats these technologies, such as data surveillance, present to our sense of privacy, while also outlining the opportunities for pro-social developments. Provides a theory of the web in the context of the history...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

  7. Implementing NetScaler VPX

    CERN Document Server

    Sandbu, Marius

    2014-01-01

    An easy-to-follow guide with detailed step-by step-instructions on how to implement the different key components in NetScaler, with real-world examples and sample scenarios.If you are a Citrix or network administrator who needs to implement NetScaler in your virtual environment to gain an insight on its functionality, this book is ideal for you. A basic understanding of networking and familiarity with some of the different Citrix products such as XenApp or XenDesktop is a prerequisite.

  8. Quantifying the net benefit impacts of the Troy Waste Water Treatment Plant on Steelhead Habitat in the West Fork Little Bear Creek drainage

    Science.gov (United States)

    Sanchez-Murillo, R.; Brooks, E. S.; Boll, J.

    2010-12-01

    Discharge of waste water treatment plants (WWTPs) typically is viewed to result in water quality impairment. However, WWTPs can also be a source of nutrients to enhance the salmonid food web as well as an efficient way to maintain acceptable water temperature regimes and flow conditions during summer. We observed this paradox in West Fork Little Bear Creek (WFLB) in the City of Troy, Idaho. Despite the nutrient load, the WFLB had the highest Steelhead trout density in the watershed, with a mean density of 13.2 fish/100 m2. The objective of this project was to utilize a water quality model, QUAL2kw, and an ecology assessment to examine how the nutrient load from the WWTP affects: a) habitat conditions for steelhead juveniles, and b) physic-chemical parameters. Four monitoring stations were installed from May through November in 2009 and 2010. An undisturbed creek was used as a control site in 2010. Dissolved oxygen (DO), electrical conductivity, temperature, and discharge were measured continuously at each monitoring station. Weekly samples were collected at each monitoring station and analyzed for nitrate, nitrite, ammonia, total Kjeldahl nitrogen, total phosphorous, and orthophosphates. In 2010, Chlorophyll a was analyzed weekly, while bottom algae biomass was determined monthly. Results show that during summer months, the WWTP provides the majority of the flow (0.1 cfs) in the creek. Water samples and DO measurements taken 200 m downstream of the plant during late summer months indicate that nitrification process leads to low DO level well below the state standard of 6 mg/L for cold water biota. However dissolved oxygen levels recover within 1 km downstream. Discharge data suggest that without the flow from the treatment most of the creek would dry during late summer months. Abundance of macroinverbrates, high primary productivity, and sustained flow during summer suggests that the effluent from the WWTP is a net benefit to the Steelhead habitat in the basin

  9. Estimation of net ecosystem metabolism of seagrass meadows in the coastal waters of the East Sea and Black Sea using the noninvasive eddy covariance technique

    Science.gov (United States)

    Lee, Jae Seong; Kang, Dong-Jin; Hineva, Elitsa; Slabakova, Violeta; Todorova, Valentina; Park, Jiyoung; Cho, Jin-Hyung

    2017-06-01

    We measured the community-scale metabolism of seagrass meadows in Bulgaria (Byala [BY]) and Korea (Hoopo Bay [HP]) to understand their ecosystem function in coastal waters. A noninvasive in situ eddy covariance technique was applied to estimate net O2 flux in the seagrass meadows. From the high-quality and high-resolution time series O2 data acquired over > 24 h, the O2 flux driven by turbulence was extracted at 15-min intervals. The spectrum analysis of vertical flow velocity and O2 concentration clearly showed well-developed turbulence characteristics in the inertial subrange region. The hourly averaged net O2 fluxes per day ranged from -474 to 326 mmol O2 m-2 d-1 (-19 ± 41 mmol O2 m-2 d-1) at BY and from -74 to 482 mmol O2 m-2 d-1 (31 ± 17 mmol O2 m-2 d-1) at HP. The net O2 production rapidly responded to photosynthetically available radiation (PAR) and showed a good relationship between production and irradiance (P-I curve). The hysteresis pattern of P-I relationships during daytime also suggested increasing heterotrophic respiration in the afternoon. With the flow velocity between 3.30 and 6.70 cm s-1, the community metabolism during daytime and nighttime was significantly increased by 20 times and 5 times, respectively. The local hydrodynamic characteristics may be vital to determining the efficiency of community photosynthesis. The net ecosystem metabolism at BY was estimated to be -17 mmol O2 m-2 d-1, which was assessed as heterotrophy. However, that at HP was 36 mmol O2 m-2 d-1, which suggested an autotrophic state.

  10. A two-step approach to estimating selectivity and fishing power of research gill nets used in Greenland waters

    DEFF Research Database (Denmark)

    Hovgård, Holger

    1996-01-01

    by normal distributions and could be related to mesh size in accordance with the principle of geometrical similarity. In the second step the selection parameters were estimated by a nonlinear least squares fit. The model also estimated the relative efficiency of the two capture processes and the fishing......Catches of Atlantic cod (Gadus morhua) from Greenland gill-net surveys were analyzed by a two-step approach. In the initial step the form of the selection curve was identified as binormal, which was caused by fish being gilled or caught by the maxillae. Both capture processes could be described...

  11. Hydraulic redistribution of soil water by roots affects whole-stand evapotranspiration and net ecosystem carbon exchange

    Science.gov (United States)

    J.-C. Domec; J.S. King; A. Noormets; E. Treasure; M.J. Gavazzi; G. Sun; S.G. McNulty

    2010-01-01

    Hydraulic redistribution (HR) of water via roots from moist to drier portions of the soil occurs in many ecosystems, potentially influencing both water use and carbon assimilation. By measuring soil water content, sap flow and eddy covariance, we investigated the temporal variability of HR in a loblolly pine (Pinus taeda) plantation during months of...

  12. Target specific proteochemometric model development for BACE1 - protein flexibility and structural water are critical in virtual screening.

    Science.gov (United States)

    Manoharan, Prabu; Chennoju, Kiranmai; Ghoshal, Nanda

    2015-07-01

    BACE1 is an attractive target in Alzheimer's disease (AD) treatment. A rational drug design effort for the inhibition of BACE1 is actively pursued by researchers in both academic and pharmaceutical industries. This continued effort led to the steady accumulation of BACE1 crystal structures, co-complexed with different classes of inhibitors. This wealth of information is used in this study to develop target specific proteochemometric models and these models are exploited for predicting the prospective BACE1 inhibitors. The models developed in this study have performed excellently in predicting the computationally generated poses, separately obtained from single and ensemble docking approaches. The simple protein-ligand contact (SPLC) model outperforms other sophisticated high end models, in virtual screening performance, developed during this study. In an attempt to account for BACE1 protein active site flexibility information in predictive models, we included the change in the area of solvent accessible surface and the change in the volume of solvent accessible surface in our models. The ensemble and single receptor docking results obtained from this study indicate that the structural water mediated interactions improve the virtual screening results. Also, these waters are essential for recapitulating bioactive conformation during docking study. The proteochemometric models developed in this study can be used for the prediction of BACE1 inhibitors, during the early stage of AD drug discovery.

  13. Mineralocorticoid receptor stimulation effects on spatial memory in healthy young adults: A study using the virtual Morris Water Maze task.

    Science.gov (United States)

    Piber, Dominique; Schultebraucks, Katharina; Mueller, Sven C; Deuter, Christian Eric; Wingenfeld, Katja; Otte, Christian

    2016-12-01

    Stress hormones such as cortisol are known to influence a wide range of cognitive functions, including hippocampal based spatial memory. In the brain, cortisol acts via two different receptors: the glucocorticoid (GR) and the mineralocorticoid receptor (MR). As the MR has a high density in the hippocampus, we examined the effects of pharmacological MR stimulation on spatial memory. Eighty healthy participants (40 women, 40 men, mean age=23.9years±SD=3.3) completed the virtual Morris Water Maze (vMWM) task to test spatial encoding and spatial memory retrieval after receiving 0.4mg fludrocortisone, a MR agonist, or placebo. There was no effect of MR stimulation on spatial encoding during the vMWM task. However, participants who received fludrocortisone exhibited improved spatial memory retrieval performance. There was neither a main effect of sex nor a sex-by-treatment interaction. In young healthy participants, MR stimulation improved hippocampal based spatial memory retrieval in a virtual Morris Water Maze task. Our study not only confirms the importance of MR function in spatial memory, but suggests beneficial effects of acute MR stimulation on spatial memory retrieval in humans. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. KM3NeT

    CERN Multimedia

    KM3NeT is a large scale next-generation neutrino telescope located in the deep waters of the Mediterranean Sea, optimized for the discovery of galactic neutrino sources emitting in the TeV energy region.

  15. Virtually teaching virtual leadership

    DEFF Research Database (Denmark)

    Henriksen, Thomas Duus; Nielsen, Rikke Kristine; Børgesen, Kenneth

    2017-01-01

    This paper seeks to investigate the challenges to virtual collaboration and leadership on basis of findings from a virtual course on collaboration and leadership. The course used for this experiment was designed as a practical approach, which allowed participants to experience curriculum phenomena....... This experimental course provided insights into the challenges involved in virtual processes, and those experiences where used for addressing the challenges that virtual leadership is confronted with. Emphasis was placed on the reduction of undesired virtual distance and its consequences through affinity building....... We found that student scepticism appeared when a breakdown resulted in increasing virtual distance, and raises questions on how leaders might translate or upgrade their understandings of leadership to handling such increased distance through affinity building....

  16. Analysis of the characteristics of the global virtual water trade network using degree and eigenvector centrality, with a focus on food and feed crops

    Directory of Open Access Journals (Sweden)

    S.-H. Lee

    2016-10-01

    Full Text Available This study aims to analyze the characteristics of global virtual water trade (GVWT, such as the connectivity of each trader, vulnerable importers, and influential countries, using degree and eigenvector centrality during the period 2006–2010. The degree centrality was used to measure the connectivity, and eigenvector centrality was used to measure the influence on the entire GVWT network. Mexico, Egypt, China, the Republic of Korea, and Japan were classified as vulnerable importers, because they imported large quantities of virtual water with low connectivity. In particular, Egypt had a 15.3 Gm3 year−1 blue water saving effect through GVWT: the vulnerable structure could cause a water shortage problem for the importer. The entire GVWT network could be changed by a few countries, termed "influential traders". We used eigenvector centrality to identify those influential traders. In GVWT for food crops, the USA, Russian Federation, Thailand, and Canada had high eigenvector centrality with large volumes of green water trade. In the case of blue water trade, western Asia, Pakistan, and India had high eigenvector centrality. For feed crops, the green water trade in the USA, Brazil, and Argentina was the most influential. However, Argentina and Pakistan used high proportions of internal water resources for virtual water export (32.9 and 25.1 %; thus other traders should carefully consider water resource management in these exporters.

  17. Analysis of the characteristics of the global virtual water trade network using degree and eigenvector centrality, with a focus on food and feed crops

    Science.gov (United States)

    Lee, Sang-Hyun; Mohtar, Rabi H.; Choi, Jin-Yong; Yoo, Seung-Hwan

    2016-10-01

    This study aims to analyze the characteristics of global virtual water trade (GVWT), such as the connectivity of each trader, vulnerable importers, and influential countries, using degree and eigenvector centrality during the period 2006-2010. The degree centrality was used to measure the connectivity, and eigenvector centrality was used to measure the influence on the entire GVWT network. Mexico, Egypt, China, the Republic of Korea, and Japan were classified as vulnerable importers, because they imported large quantities of virtual water with low connectivity. In particular, Egypt had a 15.3 Gm3 year-1 blue water saving effect through GVWT: the vulnerable structure could cause a water shortage problem for the importer. The entire GVWT network could be changed by a few countries, termed "influential traders". We used eigenvector centrality to identify those influential traders. In GVWT for food crops, the USA, Russian Federation, Thailand, and Canada had high eigenvector centrality with large volumes of green water trade. In the case of blue water trade, western Asia, Pakistan, and India had high eigenvector centrality. For feed crops, the green water trade in the USA, Brazil, and Argentina was the most influential. However, Argentina and Pakistan used high proportions of internal water resources for virtual water export (32.9 and 25.1 %); thus other traders should carefully consider water resource management in these exporters.

  18. Virtual reality in urban water management: communicating urban flooding with particle-based CFD simulations.

    Science.gov (United States)

    Winkler, Daniel; Zischg, Jonatan; Rauch, Wolfgang

    2018-01-01

    For communicating urban flood risk to authorities and the public, a realistic three-dimensional visual display is frequently more suitable than detailed flood maps. Virtual reality could also serve to plan short-term flooding interventions. We introduce here an alternative approach for simulating three-dimensional flooding dynamics in large- and small-scale urban scenes by reaching out to computer graphics. This approach, denoted 'particle in cell', is a particle-based CFD method that is used to predict physically plausible results instead of accurate flow dynamics. We exemplify the approach for the real flooding event in July 2016 in Innsbruck.

  19. Water-saving ground cover rice production system reduces net greenhouse gas fluxes in an annual rice-based cropping system

    Science.gov (United States)

    Yao, Z.; Du, Y.; Tao, Y.; Zheng, X.; Liu, C.; Lin, S.; Butterbach-Bahl, K.

    2014-11-01

    To safeguard food security and preserve precious water resources, the technology of water-saving ground cover rice production system (GCRPS) is being increasingly adopted for rice cultivation. However, changes in soil water status and temperature under GCRPS may affect soil biogeochemical processes that control the biosphere-atmosphere exchanges of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). The overall goal of this study is to better understand how net ecosystem greenhouse gas exchanges (NEGE) and grain yields are affected by GCRPS in an annual rice-based cropping system. Our evaluation was based on measurements of the CH4 and N2O fluxes and soil heterotrophic respiration (CO2 emissions) over a complete year, and the estimated soil carbon sequestration intensity for six different fertilizer treatments for conventional paddy and GCRPS. The fertilizer treatments included urea application and no N fertilization for both conventional paddy (CUN and CNN) and GCRPS (GUN and GNN), and solely chicken manure (GCM) and combined urea and chicken manure applications (GUM) for GCRPS. Averaging across all the fertilizer treatments, GCRPS increased annual N2O emission and grain yield by 40 and 9%, respectively, and decreased annual CH4 emission by 69%, while GCRPS did not affect soil CO2 emissions relative to the conventional paddy. The annual direct emission factors of N2O were 4.01, 0.09 and 0.50% for GUN, GCM and GUM, respectively, and 1.52% for the conventional paddy (CUN). The annual soil carbon sequestration intensity under GCRPS was estimated to be an average of -1.33 Mg C ha-1 yr-1, which is approximately 44% higher than the conventional paddy. The annual NEGE were 10.80-11.02 Mg CO2-eq ha-1 yr-1 for the conventional paddy and 3.05-9.37 Mg CO2-eq ha-1 yr-1 for the GCRPS, suggesting the potential feasibility of GCRPS in reducing net greenhouse effects from rice cultivation. Using organic fertilizers for GCRPS considerably reduced annual emissions of CH4

  20. CPN Tools-Assisted Simulation and Verification of Nested Petri Nets

    Directory of Open Access Journals (Sweden)

    L. W. Dworza´nski

    2012-01-01

    Full Text Available Nested Petri nets (NP-nets are an extension of Petri net formalism within the “netswithin-nets” approach, when tokens in a marking are Petri nets, which have an autonomous behavior and are synchronized with the system net. The formalism of NP-nets allows modeling multi-level multi-agent systems with dynamic structure in a natural way. Currently, there is no tool for supporting NP-nets simulation and analysis. The paper proposes the translation of NP-nets into Colored Petri nets and the use of CPN Tools as a virtual machine for NP-nets modeling, simulation and automatic verification.

  1. Time series for water levels in virtual gauge stations in the Amazon basin using satellite radar altimetry

    Directory of Open Access Journals (Sweden)

    Juan Gabriel León Hernández

    2009-01-01

    Full Text Available Using satellite altimeter radar technology for monitoring changes in water levels at continental scale is a relatively recent ad- vance. Several studies have demonstrated the interest being shown in applying this technology to monitoring the hydrographic patterns of large-scale basins worldwide. The current study presents the inference of time series representing changes in water le- vel for bodies of water by defining virtual gauge stations deduced for two very different rivers in terms of their biophysical and to- pographic characteristics; the two rivers were the Rio Negro in the Brazilian Amazon Basin and the Caqueta River on the Colombian side. The differences between the two rivers revealed the limits of satellite radar altimeter when applied to continental waters (±20cm and ±40 cm precision for Río Negro and Río Caquetá, respectively. However, applying this technology seems very promising, since new missions have been scheduled to be put into orbit by the end of 2008.

  2. INMARSAT-C SafetyNET

    Science.gov (United States)

    Tsunamis 406 EPIRB's National Weather Service Marine Forecasts INMARSAT-C SafetyNET Marine Forecast Offices greater danger near shore or any shallow waters? NATIONAL WEATHER SERVICE PRODUCTS VIA INMARSAT-C SafetyNET Inmarsat-C SafetyNET is an internationally adopted, automated satellite system for promulgating

  3. Trade in and Valuation of Virtual Water Impacts in a City: A Case Study Of Flagstaff, Arizona

    Science.gov (United States)

    Rushforth, R.; Ruddell, B. L.

    2013-12-01

    An increasingly intense component of the global coupled natural and human system (CNH) is the economic trade of various types of resources and the outsourcing of resource impacts between geographically distant economic systems. The human economy's trade arrangements allow specific localities, especially cities, to exceed spatially local resource stock sustainability and footprint constraints, as evidenced in the urban metabolism literature. Each movement or trade of a resource along a network is associated with an embedded or 'virtual' exchange of indirect impacts on the inputs to the production process. The networked trade of embedded resources, therefore, is an essential human adaptation to resource limitations. Using the Embedded Resource Impact Accounting (ERA) framework, we examine the network of embedded water flows created through the trade of goods and services and economic development in Flagstaff, Arizona, and associate these flows with the creation of value in sectors of the economy

  4. Open challenges in structure-based virtual screening: Receptor modeling, target flexibility consideration and active site water molecules description.

    Science.gov (United States)

    Spyrakis, Francesca; Cavasotto, Claudio N

    2015-10-01

    Structure-based virtual screening is currently an established tool in drug lead discovery projects. Although in the last years the field saw an impressive progress in terms of algorithm development, computational performance, and retrospective and prospective applications in ligand identification, there are still long-standing challenges where further improvement is needed. In this review, we consider the conceptual frame, state-of-the-art and recent developments of three critical "structural" issues in structure-based drug lead discovery: the use of homology modeling to accurately model the binding site when no experimental structures are available, the necessity of accounting for the dynamics of intrinsically flexible systems as proteins, and the importance of considering active site water molecules in lead identification and optimization campaigns. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Carbon dioxide flux and net primary production of a boreal treed bog: Responses to warming and water-table-lowering simulations of climate change

    Science.gov (United States)

    Munir, T. M.; Perkins, M.; Kaing, E.; Strack, M.

    2015-02-01

    Midlatitude treed bogs represent significant carbon (C) stocks and are highly sensitive to global climate change. In a dry continental treed bog, we compared three sites: control, recent (1-3 years; experimental) and older drained (10-13 years), with water levels at 38, 74 and 120 cm below the surface, respectively. At each site we measured carbon dioxide (CO2) fluxes and estimated tree root respiration (Rr; across hummock-hollow microtopography of the forest floor) and net primary production (NPP) of trees during the growing seasons (May to October) of 2011-2013. The CO2-C balance was calculated by adding the net CO2 exchange of the forest floor (NEff-Rr) to the NPP of the trees. From cooler and wetter 2011 to the driest and the warmest 2013, the control site was a CO2-C sink of 92, 70 and 76 g m-2, the experimental site was a CO2-C source of 14, 57 and 135 g m-2, and the drained site was a progressively smaller source of 26, 23 and 13 g CO2-C m-2. The short-term drainage at the experimental site resulted in small changes in vegetation coverage and large net CO2 emissions at the microforms. In contrast, the longer-term drainage and deeper water level at the drained site resulted in the replacement of mosses with vascular plants (shrubs) on the hummocks and lichen in the hollows leading to the highest CO2 uptake at the drained hummocks and significant losses in the hollows. The tree NPP (including above- and below-ground growth and litter fall) in 2011 and 2012 was significantly higher at the drained site (92 and 83 g C m-2) than at the experimental (58 and 55 g C m-2) and control (52 and 46 g C m-2) sites. We also quantified the impact of climatic warming at all water table treatments by equipping additional plots with open-top chambers (OTCs) that caused a passive warming on average of ~ 1 °C and differential air warming of ~ 6 °C at midday full sun over the study years. Warming significantly enhanced shrub growth and the CO2 sink function of the drained

  6. Integrated Flood Forecast and Virtual Dam Operation System for Water Resources and Flood Risk Management

    Science.gov (United States)

    Shibuo, Yoshihiro; Ikoma, Eiji; Lawford, Peter; Oyanagi, Misa; Kanauchi, Shizu; Koudelova, Petra; Kitsuregawa, Masaru; Koike, Toshio

    2014-05-01

    While availability of hydrological- and hydrometeorological data shows growing tendency and advanced modeling techniques are emerging, such newly available data and advanced models may not always be applied in the field of decision-making. In this study we present an integrated system of ensemble streamflow forecast (ESP) and virtual dam simulator, which is designed to support river and dam manager's decision making. The system consists of three main functions: real time hydrological model, ESP model, and dam simulator model. In the real time model, the system simulates current condition of river basins, such as soil moisture and river discharges, using LSM coupled distributed hydrological model. The ESP model takes initial condition from the real time model's output and generates ESP, based on numerical weather prediction. The dam simulator model provides virtual dam operation and users can experience impact of dam control on remaining reservoir volume and downstream flood under the anticipated flood forecast. Thus the river and dam managers shall be able to evaluate benefit of priori dam release and flood risk reduction at the same time, on real time basis. Furthermore the system has been developed under the concept of data and models integration, and it is coupled with Data Integration and Analysis System (DIAS) - a Japanese national project for integrating and analyzing massive amount of observational and model data. Therefore it has advantage in direct use of miscellaneous data from point/radar-derived observation, numerical weather prediction output, to satellite imagery stored in data archive. Output of the system is accessible over the web interface, making information available with relative ease, e.g. from ordinary PC to mobile devices. We have been applying the system to the Upper Tone region, located northwest from Tokyo metropolitan area, and we show application example of the system in recent flood events caused by typhoons.

  7. Accuracy assessment of a net radiation and temperature index snowmelt model using ground observations of snow water equivalent in an alpine basin

    Science.gov (United States)

    Molotch, N. P.; Painter, T. H.; Bales, R. C.; Dozier, J.

    2003-04-01

    In this study, an accumulated net radiation / accumulated degree-day index snowmelt model was coupled with remotely sensed snow covered area (SCA) data to simulate snow cover depletion and reconstruct maximum snow water equivalent (SWE) in the 19.1-km2 Tokopah Basin of the Sierra Nevada, California. Simple net radiation snowmelt models are attractive for operational snowmelt runoff forecasts as they are computationally inexpensive and have low input requirements relative to physically based energy balance models. The objective of this research was to assess the accuracy of a simple net radiation snowmelt model in a topographically heterogeneous alpine environment. Previous applications of net radiation / temperature index snowmelt models have not been evaluated in alpine terrain with intensive field observations of SWE. Solar radiation data from two meteorological stations were distributed using the topographic radiation model TOPORAD. Relative humidity and temperature data were distributed based on the lapse rate calculated between three meteorological stations within the basin. Fractional SCA data from the Landsat Enhanced Thematic Mapper (5 acquisitions) and the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) (2 acquisitions) were used to derive daily SCA using a linear regression between acquisition dates. Grain size data from AVIRIS (4 acquisitions) were used to infer snow surface albedo and interpolated linearly with time to derive daily albedo values. Modeled daily snowmelt rates for each 30-m pixel were scaled by the SCA and integrated over the snowmelt season to obtain estimates of maximum SWE accumulation. Snow surveys consisting of an average of 335 depth measurements and 53 density measurements during April, May and June, 1997 were interpolated using a regression tree / co-krig model, with independent variables of average incoming solar radiation, elevation, slope and maximum upwind slope. The basin was clustered into 7 elevation / average

  8. Water exposure assessment of aryl hydrocarbon receptor agonists in Three Gorges Reservoir, China using SPMD-based virtual organisms.

    Science.gov (United States)

    Wang, Jingxian; Bernhöft, Silke; Pfister, Gerd; Schramm, Karl-Werner

    2014-10-15

    SPMD-based virtual organisms (VOs) were deployed at five to eight sites in the Three Gorges Reservoir (TGR), China for five periods in 2008, 2009 and 2011. The water exposure of aryl hydrocarbon receptor (AhR) agonists was assessed by the VOs. The chosen bioassay response for the extracts of the VOs, the induction of 7-ethoxyresorufin-O-deethylase (EROD) was assayed using a rat hepatoma cell line (H4IIE). The results show that the extracts from the VOs could induce AhR activity significantly, whereas the chemically derived 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalent (TEQcal) accounted for water level reached a maximum of 175 m. Although the aqueous concentration of AhR agonists of 0.8-4.8 pg TCDDL(-1) in TGR was not alarming, the tendency of accumulating high concentration of AhR agonists in VO lipid and existence of possible synergism or antagonism in the water may exhibit a potential hazard to local biota being exposed to AhR agonists. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Moderate water stress from regulated deficit irrigation decreases transpiration similarly to net carbon exchange in grapevine canopies

    Science.gov (United States)

    To determine the effects of timing and extent of regulated deficit irrigation (RDI) on grapevine (Vitis vinifera) canopies, whole-canopy transpiration (TrV) and canopy conductance to water vapor (gc) were calculated from whole-vine gas exchange near key stages of fruit development. The vines were ma...

  10. Quantitative description of the relation between protein net charge and protein adsorption to air-water interfaces

    NARCIS (Netherlands)

    Wierenga, P.A.; Meinders, M.B.J.; Egmond, M.R.; Voragen, A.G.J.; Jongh, H.H.J.de

    2005-01-01

    In this study a set of chemically engineered variants of ovalbumin was produced to study the effects of electrostatic charge on the adsorption kinetics and resulting surface pressure at the air-water interface. The modification itself was based on the coupling of succinic anhydride to lysine

  11. First testing of an AUV mission planning and guidance system for water quality monitoring and fish behavior observation in net cage fish farming

    Directory of Open Access Journals (Sweden)

    D. Karimanzira

    2014-12-01

    Full Text Available Recently, underwater vehicles have become low cost, reliable and affordable platforms for performing various underwater tasks. While many aquaculture systems are closed with no harmful output, open net cage fish farms and land-based fish farms can discharge significant amounts of wastewater containing nutrients, chemicals, and pharmaceuticals that impact on the surrounding environment. Although aquaculture development has often occurred outside a regulatory framework, government oversight is increasingly common at both the seafood quality control level, and at baseline initiatives addressing the basic problem of pollution generated by culture operations, e.g. the European marine and maritime directives. This requires regular, sustainable and cost-effective monitoring of the water quality. Such monitoring needs devices to detect the water quality in a large sea area at different depths in real time. This paper presents a concept for a guidance system for a carrier (an autonomous underwater vehicle of such devices for the automated detection and analysis of water quality parameters.

  12. Relationships between regional economic sectors and water use in a water-scarce area in China: A quantitative analysis

    Science.gov (United States)

    Wang, Weiping; Gao, Lei; Liu, Pin; Hailu, Atakelty

    2014-07-01

    Northern China has been facing severe water scarcity as a result of vigorous economic growth, population expansion and changing lifestyles. A typical case is Shandong province whose water resources per capita is approximately only a sixth of the national average and a twentieth of the global average. It is useful to assess the implications of the province’s growth and trade patterns for water use and water conservation strategies. This study quantitatively analyses relationships between regional economic sectors and water use in Shandong using an input-output model for virtual water resources. The changes in key indicators for 1997-2007 are tracked and the effects of water-saving policies on these changes are examined. The results highlight the benefits of applying a virtual water trade analysis on a water-scarce region where water resources exhibit highly heterogeneous temporal and geographical distributions. The net export of virtual water in Shandong was initially large, but this declined over the years and the province has recently become a net importer. Between 1997 and 2002, water use in most sectors increased due to rapid urbanisation and industrialisation. Since then, water use in all Shandong economic sectors exhibit a downward trend despite continued increases in goods and services net exports, a trend which can be attributed to the vigorous implementation of water-saving policies and measures, especially water use quotas. Economic sectors consume water directly and indirectly and understanding the pattern of virtual water trade implied by sectoral relationships is important for managing water scarcity problems. This study fills the knowledge gap in the existing literature created by the lack of case studies that dynamically assess virtual water trade and analyse the effects of water-saving policies and measures. The study draws policy recommendations that are relevant for future water planning in Shandong and other regions in northern China.

  13. Virtual colonoscopy

    Science.gov (United States)

    Colonoscopy - virtual; CT colonography; Computed tomographic colonography; Colography - virtual ... Differences between virtual and conventional colonoscopy include: VC can view the colon from many different angles. This is not as easy ...

  14. Web-Based Virtual Environments for Decision Support in Water Systems

    NARCIS (Netherlands)

    Zhu, X.

    2013-01-01

    Computer graphics and scientific visualization are fields of computational science that have evolved rapidly over the past decades. Scientific visualization has become an important technology in serious gaming and science-based decision support. Water management is a complex process dealing with a

  15. Factors influencing the residence time of catchment waters : A virtual experiment approach

    NARCIS (Netherlands)

    Dunn, S.M.; McDonnell, J.J.; Vaché, K.B.

    Estimates of mean residence time (MRT) are increasingly used as simple summary descriptors of the hydrological processes involving storage and mixing of water within catchment systems. Current understanding of the physical controls on MRT remains limited, and various hypotheses have been proposed to

  16. CM Net heterogeneous local network of microcomputers

    International Nuclear Information System (INIS)

    Gutche, R.Kh.

    1988-01-01

    Realization of the CM Net heterogeneous local network for the PDP-11 type computers with the RT-11 operational system control is described. The main advantage of the network is the realization of virtual disks in general form including a system unit. the network can be used everywhere, where the problem on computer connection by simple interfaces is stated. 6 refs

  17. Desempenho do modelo AcquaNetXL na alocação de água em sistemas de recursos hídricos complexos Performance of the model called AcquaNetXL in the allocation of water in complex water resource systems

    Directory of Open Access Journals (Sweden)

    André Schardong

    2009-01-01

    Full Text Available Este artigo apresenta uma ferramenta para análise de sistemas complexos de recursos hídricos denominada AcquaNetXL, que foi desenvolvida no formato de planilha eletrônica, na qual foram incorporados dois modelos de otimização, um linear e outro não linear. Essa ferramenta mantém os conceitos e os atributos de um sistema de suporte a decisão, ou seja, possui as características de estreitar a comunicação entre o usuário e o computador, de facilitar o entendimento, a formulação do problema, a interpretação dos resultados de análise e auxiliar no processo de tomada de decisão, tornando-o mais ordenado, objetivo e transparente. O desempenho do algoritmo utilizado na solução dos problemas de alocação de água foi satisfatório, especialmente para o modelo linear.This article presents a tool for the allocation analysis of complex systems of water resources, called AcquaNetXL, developed in the form of spreadsheet in which a model of linear optimization and another nonlinear were incorporated. The AcquaNetXL keeps the concepts and attributes of a decision support system. In other words, it straightens out the communication between the user and the computer, facilitates the understanding and the formulation of the problem, the interpretation of the results and it also gives a support in the process of decision making, turning it into a clear and organized process. The performance of the algorithms used for solving the problems of water allocation was satisfactory especially for the linear model.

  18. How water is different from energy and food?

    Science.gov (United States)

    Hanasaki, N.; Oki, T.; Yano, S.

    2017-12-01

    Although water is rarely traded over long distances by itself, the total weight of the water consumed to produce traded commodities exceeds the weight of any other commodity traded in the world. This concept is known as virtual water trade. Although space-/time-/commodity-based quantification has been conducted extensively, the underlying causes of this peculiar feature have thus far received little exploration. Here, we use estimates of water consumption from a global hydrological model and statistical data related to food trade to elucidate three facts that explain the fundamental nature of virtual water trade with respect to alleviating water scarcity. First, we quantitatively illustrate the unique position of water among commodities based on its unit price and quantity of sales. Water has an extremely low unit price, and a tremendous volume of water is consumed per person each day. Second, we show that rich but water-scarce countries tend to reduce local water consumption by importing virtual water. Third, we demonstrate that nations characterized by net virtual water exports have higher water resources and income per capita and that no countries fall below a certain threshold with respect to both GDP and water resources. These points suggest that the virtual water trade is explained by economic characteristics of water and that sustainable development depends on promoting the co-development of poverty alleviation and water resource development.

  19. History of Virtual Water , International Trade and Economic Metabolism at the Time Colonialism and a First Attempt to Assess Their Impact on Hydrologic Changes

    Science.gov (United States)

    Greco, F.

    2008-12-01

    This research considers the historical impact of virtual water into the geophysical arena by considering it as a human-led phenomenon that impacts the hydrologic system and, consequently, the environment as a whole. This paper is in line with the idea of including the humans into the water-balance model, and it is deepening the idea that this has to be done not only at the light of each watershed, but globally, looking at the role of water-trade embedded in food and tradable goods. Starting from a definition of what virtual water is, this research explores the role of crops export in the early U.S. Colonial time. As early as 1630 a huge biomass from here was already exported to the UK (the fur trade). In 1700 the tobacco export started, along with cereals exports and timber. An entire ecosystem has been "exported" in terms of water-embedded-in-goods. This was the beginning of a massive depletion of bio-mass stocks and flows, a raise in nitrogen discharge into the environment and its impact on the hydrological systems ( CUAHSI Summer Institute findings). Immigration and its effects on the water balance is also considered in this work. The experiment of interdisciplinary work of CUAHSI Summer Institute 2008 has proven that there is space for a historical reconstruction of evidence of human-led changes to the hydrological systems. This has been possible through the analysis of material stocks and flows, water-balance analysis of these stocks and flows, including human-led changes like international trade and population growth. This proposal will argue that these changes can also be identified by the term of 'socio- economic metabolism', in which societies are trading their goods internationally but taking the primary resources, including water, locally. This work will put the basis for the history of virtual water and its implications on both socio-economic metabolism and local geophysical changes.

  20. MOOving around the Net: The Educational Potential of MOOs.

    Science.gov (United States)

    1996

    The use of MOOs, multi-user simulated environments in education examined in three papers include: "MOOving around the Net: The Educational Potential of MOOs: A Point of View" (Daniel Ingvarson); "MOOing in a Foreign Language: How, Why and Who?" (Lonnie Turbee) and "MOOving around the Net: Real to Virtual and Back…

  1. Virtual Class Support at the Virtual Machine Level

    DEFF Research Database (Denmark)

    Nielsen, Anders Bach; Ernst, Erik

    2009-01-01

    This paper describes how virtual classes can be supported in a virtual machine.  Main-stream virtual machines such as the Java Virtual Machine and the .NET platform dominate the world today, and many languages are being executed on these virtual machines even though their embodied design choices...... conflict with the design choices of the virtual machine.  For instance, there is a non-trivial mismatch between the main-stream virtual machines mentioned above and dynamically typed languages.  One language concept that creates an even greater mismatch is virtual classes, in particular because fully...... general support for virtual classes requires generation of new classes at run-time by mixin composition.  Languages like CaesarJ and ObjectTeams can express virtual classes restricted to the subset that does not require run-time generation of classes, because of the restrictions imposed by the Java...

  2. Dry preparation for virtual CT colonography with fecal tagging using water-soluble contrast medium: initial results

    International Nuclear Information System (INIS)

    Bielen, Didier; Thomeer, Maarten; Vanbeckevoort, Dirk; Marchal, Guy; Kiss, Gabriel; Maes, Frederik; Rutgeerts, Paul

    2003-01-01

    The purpose of this study was to evaluate the feasibility of a dry bowel preparation, i.e. without laxative fluids, for virtual CT colonography (VCTC), and its impact on patient acceptance compared with conventional colonoscopy (CC). A randomly chosen patient population scheduled for CC (n=11) was first submitted to VCTC after a dry preparation, consisting of low-residue meals combined with a small amount of a iodinated water-soluble contrast medium during each meal 3 days before VCTC. In different colon segments and between different persons, the degree of tagging in VCTC was evaluated and graded. Patient acceptance and future preference were assessed for both preparations as well as for both investigations. The mixing of the contrast with the intestinal content results in contrast impregnated stool, the tagged feces. The degree of fecal tagging was good in the majority of the patients and the colonic segments, especially in the descending colon and sigmoid. Furthermore, patient acceptance and preference were clearly in favour of VCTC compared with CC merely because of the non-invasiveness of the dry preparation. Dry bowel preparation and VCTC is a promising approach towards a patient-friendly colon cancer-screening setup. (orig.)

  3. A Preliminary Study of Functional Brain Activation among Marijuana Users during Performance of a Virtual Water Maze Task

    Directory of Open Access Journals (Sweden)

    Jennifer Tropp Sneider

    2013-01-01

    Full Text Available Numerous studies have reported neurocognitive impairments associated with chronic marijuana use. Given that the hippocampus contains a high density of cannabinoid receptors, hippocampal-mediated cognitive functions, including visuospatial memory, may have increased vulnerability to chronic marijuana use. Thus, the current study examined brain activation during the performance of a virtual analogue of the classic Morris water maze task in 10 chronic marijuana (MJ users compared to 18 nonusing (NU comparison subjects. Imaging data were acquired using blood oxygen level-dependent (BOLD functional MRI at 3.0 Tesla during retrieval (hidden platform and motor control (visible platform conditions. While task performance on learning trials was similar between groups, MJ users demonstrated a deficit in memory retrieval. For BOLD fMRI data, NU subjects exhibited greater activation in the right parahippocampal gyrus and cingulate gyrus compared to the MJ group for the Retrieval-Motor Control contrast (NU > MJ. These findings suggest that hypoactivation in MJ users may be due to differences in the efficient utilization of neuronal resources during the retrieval of memory. Given the paucity of data on visuospatial memory function in MJ users, these findings may help elucidate the neurobiological effects of marijuana on brain activation during memory retrieval.

  4. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1987-01-01

    The author describes a Petri net model, called coloured Petri nets (CP-nets), by means of which it is possible to describe large systems without having to cope with unnecessary details. The author introduces CP-nets and provide a first impression of their modeling power and the suitability...

  5. Learning Visual Basic NET

    CERN Document Server

    Liberty, Jesse

    2009-01-01

    Learning Visual Basic .NET is a complete introduction to VB.NET and object-oriented programming. By using hundreds of examples, this book demonstrates how to develop various kinds of applications--including those that work with databases--and web services. Learning Visual Basic .NET will help you build a solid foundation in .NET.

  6. The annual cycle of nitrate and net community production in surface waters of the Southern Ocean observed with SOCCOM profiling floats

    Science.gov (United States)

    Johnson, K. S.; Plant, J. N.; Sakamoto, C.; Coletti, L. J.; Sarmiento, J. L.; Riser, S.; Talley, L. D.

    2016-12-01

    Sixty profiling floats with ISUS and SUNA nitrate sensors have been deployed in the Southern Ocean (south of 30 degrees S) as part of the SOCCOM (Southern Ocean Carbon and Climate Observations and Modeling) program and earlier efforts. These floats have produced detailed records of the annual cycle of nitrate concentration throughout the region from the surface to depths near 2000 m. In surface waters, there are clear cycles in nitrate concentration that result from uptake of nitrate during austral spring and summer. These changes in nitrate concentration were used to compute the annual net community production over this region. NCP was computed using a simplified version of the approach detailed by Plant et al. (2016, Global Biogeochemical Cycles, 30, 859-879, DOI: 10.1002/2015GB005349). At the time the abstract was written 41 complete annual cycles were available from floats deployed before the austral summer of 2015/2016. After filtering the data to remove floats that crossed distinct frontal boundaries, floats with other anomalies, and floats in sub-tropical waters, 23 cycles were available. A preliminary assessment of the data yields an NCP of 2.8 +/- 0.95 (1 SD) mol C/m2/y after integrating to 100 m depth and converting nitrate uptake to carbon using the Redfield ratio. This preliminary assessment ignores vertical transport across the nitracline and is, therefore, a minimum estimate. The number of cycles available for analysis will increase rapidly, as 32 of the floats were deployed in the austral summer of 2015/2016 and have not yet been analyzed.

  7. Net global warming potential and greenhouse gas intensity as affected by different water management strategies in Chinese double rice-cropping systems.

    Science.gov (United States)

    Wu, Xiaohong; Wang, Wei; Xie, Xiaoli; Yin, Chunmei; Hou, Haijun; Yan, Wende; Wang, Guangjun

    2018-01-15

    This study provides a complete account of global warming potential (GWP) and greenhouse gas intensity (GHGI) in relation to a long-term water management experiment in Chinese double-rice cropping systems. The three strategies of water management comprised continuous (year-round) flooding (CF), flooding during the rice season but with drainage during the midseason and harvest time (F-D-F), and irrigation only for flooding during transplanting and the tillering stage (F-RF). The CH 4 and N 2 O fluxes were measured with the static chamber method. Soil organic carbon (SOC) sequestration rates were estimated based on the changes in the carbon stocks during 1998-2014. Longer periods of soil flooding led to increased CH 4 emissions, reduced N 2 O emissions, and enhanced SOC sequestration. The net GWPs were 22,497, 8,895, and 1,646 kg CO 2 -equivalent ha -1 yr -1 for the CF, F-D-F, and F-RF, respectively. The annual rice grain yields were comparable between the F-D-F and CF, but were reduced significantly (by 13%) in the F-RF. The GHGIs were 2.07, 0.87, and 0.18 kg CO 2 -equivalent kg -1 grain yr -1 for the CF, F-D-F, and F-RF, respectively. These results suggest that F-D-F could be used to maintain the grain yields and simultaneously mitigate the climatic impact of double rice-cropping systems.

  8. System and method for determining the net output torque from a waste heat recovery system

    Science.gov (United States)

    Tricaud, Christophe; Ernst, Timothy C.; Zigan, James A.

    2016-12-13

    The disclosure provides a waste heat recovery system with a system and method for calculation of the net output torque from the waste heat recovery system. The calculation uses inputs from existing pressure and speed sensors to create a virtual pump torque sensor and a virtual expander torque sensor, and uses these sensors to provide an accurate net torque output from the WHR system.

  9. Influence of a net cage tilapia culture on the water quality of the Nova Avanhandava reservoir, São Paulo State, Brazil - doi: 10.4025/actascibiolsci.v34i3.7298

    Directory of Open Access Journals (Sweden)

    André Luiz Scarano Camargo

    2012-06-01

    Full Text Available In order to understand the influence of a net cage tilapia culture on the environment, water quality parameters were investigated during the period between December, 2005 and November, 2007. Three sampling stations were established in the reservoir of Nova Avanhandava (Zacarias, São Paulo State as follows: upstream of net cage area (P1, in the rearing place (P2 and downstream of net cage area (P3. The mean values of the parameters examined in the water sampling stations were within the standards of water quality recommended by resolution no. 357/2005 of the Conselho Nacional do Meio Ambiente for class 2 freshwater bodies. A significantly higher mean concentration of total phosphorus (p -1 was the result of the uneaten feed and feces of fish. The average concentration of total phosphorus in P3 was lower (0.015 mg L-1, which was assimilated by the aquatic ecosystem. The frequent monitoring of the water parameters is fundamental, so the producer can adjust the management according to environmental conditions, by reducing fish density or changing feeding rates for example, to mitigate or avoid water quality deterioration. 

  10. A Virtual Mixture Approach to the Study of Multistate Equilibrium: Application to Constant pH Simulation in Explicit Water

    Science.gov (United States)

    Wu, Xiongwu; Brooks, Bernard R.

    2015-01-01

    Chemical and thermodynamic equilibrium of multiple states is a fundamental phenomenon in biology systems and has been the focus of many experimental and computational studies. This work presents a simulation method to directly study the equilibrium of multiple states. This method constructs a virtual mixture of multiple states (VMMS) to sample the conformational space of all chemical states simultaneously. The VMMS system consists of multiple subsystems, one for each state. The subsystem contains a solute and a solvent environment. The solute molecules in all subsystems share the same conformation but have their own solvent environments. Transition between states is implicated by the change of their molar fractions. Simulation of a VMMS system allows efficient calculation of relative free energies of all states, which in turn determine their equilibrium molar fractions. For systems with a large number of state transition sites, an implicit site approximation is introduced to minimize the cost of simulation. A direct application of the VMMS method is for constant pH simulation to study protonation equilibrium. Applying the VMMS method to a heptapeptide of 3 ionizable residues, we calculated the pKas of those residues both with all explicit states and with implicit sites and obtained consistent results. For mouse epidermal growth factor of 9 ionizable groups, our VMMS simulations with implicit sites produced pKas of all 9 ionizable groups and the results agree qualitatively with NMR measurement. This example demonstrates the VMMS method can be applied to systems of a large number of ionizable groups and the computational cost scales linearly with the number of ionizable groups. For one of the most challenging systems in constant pH calculation, SNase Δ+PHS/V66K, our VMMS simulation shows that it is the state-dependent water penetration that causes the large deviation in lysine66’s pKa. PMID:26506245

  11. A Virtual Mixture Approach to the Study of Multistate Equilibrium: Application to Constant pH Simulation in Explicit Water.

    Directory of Open Access Journals (Sweden)

    Xiongwu Wu

    2015-10-01

    Full Text Available Chemical and thermodynamic equilibrium of multiple states is a fundamental phenomenon in biology systems and has been the focus of many experimental and computational studies. This work presents a simulation method to directly study the equilibrium of multiple states. This method constructs a virtual mixture of multiple states (VMMS to sample the conformational space of all chemical states simultaneously. The VMMS system consists of multiple subsystems, one for each state. The subsystem contains a solute and a solvent environment. The solute molecules in all subsystems share the same conformation but have their own solvent environments. Transition between states is implicated by the change of their molar fractions. Simulation of a VMMS system allows efficient calculation of relative free energies of all states, which in turn determine their equilibrium molar fractions. For systems with a large number of state transition sites, an implicit site approximation is introduced to minimize the cost of simulation. A direct application of the VMMS method is for constant pH simulation to study protonation equilibrium. Applying the VMMS method to a heptapeptide of 3 ionizable residues, we calculated the pKas of those residues both with all explicit states and with implicit sites and obtained consistent results. For mouse epidermal growth factor of 9 ionizable groups, our VMMS simulations with implicit sites produced pKas of all 9 ionizable groups and the results agree qualitatively with NMR measurement. This example demonstrates the VMMS method can be applied to systems of a large number of ionizable groups and the computational cost scales linearly with the number of ionizable groups. For one of the most challenging systems in constant pH calculation, SNase Δ+PHS/V66K, our VMMS simulation shows that it is the state-dependent water penetration that causes the large deviation in lysine66's pKa.

  12. A Virtual Mixture Approach to the Study of Multistate Equilibrium: Application to Constant pH Simulation in Explicit Water.

    Science.gov (United States)

    Wu, Xiongwu; Brooks, Bernard R

    2015-10-01

    Chemical and thermodynamic equilibrium of multiple states is a fundamental phenomenon in biology systems and has been the focus of many experimental and computational studies. This work presents a simulation method to directly study the equilibrium of multiple states. This method constructs a virtual mixture of multiple states (VMMS) to sample the conformational space of all chemical states simultaneously. The VMMS system consists of multiple subsystems, one for each state. The subsystem contains a solute and a solvent environment. The solute molecules in all subsystems share the same conformation but have their own solvent environments. Transition between states is implicated by the change of their molar fractions. Simulation of a VMMS system allows efficient calculation of relative free energies of all states, which in turn determine their equilibrium molar fractions. For systems with a large number of state transition sites, an implicit site approximation is introduced to minimize the cost of simulation. A direct application of the VMMS method is for constant pH simulation to study protonation equilibrium. Applying the VMMS method to a heptapeptide of 3 ionizable residues, we calculated the pKas of those residues both with all explicit states and with implicit sites and obtained consistent results. For mouse epidermal growth factor of 9 ionizable groups, our VMMS simulations with implicit sites produced pKas of all 9 ionizable groups and the results agree qualitatively with NMR measurement. This example demonstrates the VMMS method can be applied to systems of a large number of ionizable groups and the computational cost scales linearly with the number of ionizable groups. For one of the most challenging systems in constant pH calculation, SNase Δ+PHS/V66K, our VMMS simulation shows that it is the state-dependent water penetration that causes the large deviation in lysine66's pKa.

  13. Virtual Reality

    Science.gov (United States)

    1993-04-01

    until exhausted. SECURITY CLASSIFICATION OF THIS PAGE All other editions are obsolete. UNCLASSIFIED " VIRTUAL REALITY JAMES F. DAILEY, LIEUTENANT COLONEL...US" This paper reviews the exciting field of virtual reality . The author describes the basic concepts of virtual reality and finds that its numerous...potential benefits to society could revolutionize everyday life. The various components that make up a virtual reality system are described in detail

  14. Net primary productivity (NPP) and associated parameters for the U.S. outer continental shelf waters, 1998-2009 (NODC Accession 0071184)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession consists of monthly net primary productivity (NPP) estimates for 1998-2009 derived from the Vertically Generalized Production Model (VGPM) for the 26...

  15. A new method to determine the water activity and the net isosteric heats of sorption for low moisture foods at elevated temperatures.

    Science.gov (United States)

    Tadapaneni, Ravi Kiran; Yang, Ren; Carter, Brady; Tang, Juming

    2017-12-01

    In recent years, research studies have shown that the thermal resistance of foodborne pathogens in the low moisture foods is greatly influenced by the water activity (a w ) at temperatures relevant to thermal treatments for pathogen control. Yet, there has been a lack of an effective method for accurate measurement of a w at those temperatures. Thus, the main aim of this study was to evaluate a new method for measuring a w of food samples at elevated temperatures. An improved thermal cell with a relative humidity and temperature sensor was used to measure the a w of the three different food samples, namely, organic wheat flour, almond flour, and non-fat milk powder, over the temperature range between 20 and 80°C. For a constant moisture content, the a w data was used to estimate the net isosteric heat of sorption (q st ). The q st values were then used in the Clausius Clapeyron equation (CCE) equation to estimate the moisture sorption isotherm for all test food samples at different temperatures. For all the tested samples of any fixed moisture content, a w value generally increased with the temperature. The energy for sorption decreased with increasing moisture content. With the experimentally determined q st value, CCE describes well about the changes in a w of the food samples between 20 and 80°C. This study presents a method to obtain a w of a food sample for a specific moisture content at different temperatures which could be extended to obtain q st values for different moisture contents and hence, the moisture sorption isotherm of a food sample at different temperatures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Virtual Box

    DEFF Research Database (Denmark)

    Davis, Hilary; Skov, Mikael B.; Stougaard, Malthe

    2007-01-01

    . This paper reports on the design, implementation and initial evaluation of Virtual Box. Virtual Box attempts to create a physical and engaging context in order to support reciprocal interactions with expressive content. An implemented version of Virtual Box is evaluated in a location-aware environment...

  17. Planning of nets

    International Nuclear Information System (INIS)

    Carberry, M

    1996-01-01

    The paper is about the planning of nets in areas of low density like it is the case of the rural areas. The author includes economic and technological aspects, planning of nets, demands and management among others

  18. Annotating Coloured Petri Nets

    DEFF Research Database (Denmark)

    Lindstrøm, Bo; Wells, Lisa Marie

    2002-01-01

    Coloured Petri nets (CP-nets) can be used for several fundamentally different purposes like functional analysis, performance analysis, and visualisation. To be able to use the corresponding tool extensions and libraries it is sometimes necessary to include extra auxiliary information in the CP......-net. An example of such auxiliary information is a counter which is associated with a token to be able to do performance analysis. Modifying colour sets and arc inscriptions in a CP-net to support a specific use may lead to creation of several slightly different CP-nets – only to support the different uses...... of the same basic CP-net. One solution to this problem is that the auxiliary information is not integrated into colour sets and arc inscriptions of a CP-net, but is kept separately. This makes it easy to disable this auxiliary information if a CP-net is to be used for another purpose. This paper proposes...

  19. RadNet Air Data From Sacramento, CA

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Sacramento, CA from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  20. RadNet Air Data From Honolulu, HI

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Honolulu, HI from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  1. RadNet Air Data From Austin, TX

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Austin, TX from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  2. RadNet Air Data From Mason City, IA

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Mason City, IA from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  3. RadNet Air Data From Little Rock, AR

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Little Rock, AR from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  4. RadNet Air Data From Houston, TX

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Houston, TX from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  5. RadNet Air Data From Fort Smith, AR

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Fort Smith, AR from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  6. RadNet Air Data From Orlando, FL

    Science.gov (United States)

    This page presents radiation air monitoring and air filter analysis data for Orlando, FL from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  7. Wireless virtualization

    CERN Document Server

    Wen, Heming; Le-Ngoc, Tho

    2013-01-01

    This SpringerBriefs is an overview of the emerging field of wireless access and mobile network virtualization. It provides a clear and relevant picture of the current virtualization trends in wireless technologies by summarizing and comparing different architectures, techniques and technologies applicable to a future virtualized wireless network infrastructure. The readers are exposed to a short walkthrough of the future Internet initiative and network virtualization technologies in order to understand the potential role of wireless virtualization in the broader context of next-generation ubiq

  8. Virtual marketing in virtual enterprises

    OpenAIRE

    Ale Ebrahim, Nader; Fattahi, Hamaid Ali; Golnam, Arash

    2008-01-01

    Virtualization caused tremendous evolution in the economics of marketing channels, patterns of physical distribution and the structure of distributors and developed a new concept that is known as virtual marketing (VM). VM combines the powerful technologies of interactive marketing and virtual reality. Virtual enterprise (VE) refers to an organization not having a clear physical locus. In other words, VE is an organization distributed geographically and whose work is coordinated through e...

  9. Changes in Search Path Complexity and Length During Learning of a Virtual Water Maze: Age Differences and Differential Associations with Hippocampal Subfield Volumes.

    Science.gov (United States)

    Daugherty, Ana M; Bender, Andrew R; Yuan, Peng; Raz, Naftali

    2016-06-01

    Impairment of hippocampus-dependent cognitive processes has been proposed to underlie age-related deficits in navigation. Animal studies suggest a differential role of hippocampal subfields in various aspects of navigation, but that hypothesis has not been tested in humans. In this study, we examined the association between volume of hippocampal subfields and age differences in virtual spatial navigation. In a sample of 65 healthy adults (age 19-75 years), advanced age was associated with a slower rate of improvement operationalized as shortening of the search path over 25 learning trials on a virtual Morris water maze task. The deficits were partially explained by greater complexity of older adults' search paths. Larger subiculum and entorhinal cortex volumes were associated with a faster decrease in search path complexity, which in turn explained faster shortening of search distance. Larger Cornu Ammonis (CA)1-2 volume was associated with faster distance shortening, but not in path complexity reduction. Age differences in regional volumes collectively accounted for 23% of the age-related variance in navigation learning. Independent of subfield volumes, advanced age was associated with poorer performance across all trials, even after reaching the asymptote. Thus, subiculum and CA1-2 volumes were associated with speed of acquisition, but not magnitude of gains in virtual maze navigation. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Virtual Exploratories

    DEFF Research Database (Denmark)

    Jensen, Sisse Siggaard

    2006-01-01

    -systems, the paper introduces the designing strategy referred to as virtual exploratories. Some of the advanced virtual worlds may inspire the design of such provoking and challenging virtual exploratories, and especially the Massively Multi-User Online Role-Playing Games (MMORPGS). However, if we have to learn from...... the design and activity of the advanced virtual worlds and role-playing games, then the empirical research on the actors’ activity, while they are acting, is an important precondition to it. A step towards the conception of such a designing strategy for virtual exploratories is currently pursued....... [1] The research project: Actors and Avatars Communicating in Virtual Worlds – an Empirical Analysis of Actors’ Sense-making Strategies When Based on a Communication Theoretical Approach’ (2006-2007) is supported...

  11. Virtual Reflexes

    OpenAIRE

    Jonker, Catholijn; Broekens, Joost; Plaat, Aske

    2014-01-01

    Virtual Reality is used successfully to treat people for regular phobias. A new challenge is to develop Virtual Reality Exposure Training for social skills. Virtual actors in such systems have to show appropriate social behavior including emotions, gaze, and keeping distance. The behavior must be realistic and real-time. Current approaches consist of four steps: 1) trainee social signal detection, 2) cognitive-affective interpretation, 3) determination of the appropriate bodily responses, and...

  12. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  13. Virtual bronchoscopy

    International Nuclear Information System (INIS)

    Rogalla, P.; Meiri, N.; Hamm, B.; Rueckert, J.C.; Schmidt, B.; Witt, C.

    2001-01-01

    Flexible bronchoscopy represents a clinically well-established invasive diagnostic tool. Virtual bronchoscopies, calculated from thin-slice CT sections, allow astonishing immitations of reality although principal differences exist between both technologies: the Fact that colour representation is artificial and concommitant interventions are impossible limits the clinical use of virtual bronchoscopy. However, its value increases when calculations can be attained within minutes due to technological advancements, and when virtually any chest CT is suitable for further postprocessing. Indications, findings and the clinical role of virtual bronchoscopy are discussed. (orig.) [de

  14. Virtual projects

    DEFF Research Database (Denmark)

    Svejvig, Per; Commisso, Trine Hald

    2012-01-01

    that the best practice knowledge has not permeated sufficiently to the practice. Furthermore, the appropriate application of information and communication technology (ICT) remains a big challenge, and finally project managers are not sufficiently trained in organizing and conducting virtual projects....... The overall implications for research and practice are to acknowledge virtual project management as very different to traditional project management and to address this difference.......Virtual projects are common with global competition, market development, and not least the financial crisis forcing organizations to reduce their costs drastically. Organizations therefore have to place high importance on ways to carry out virtual projects and consider appropriate practices...

  15. Quantum net dynamics

    International Nuclear Information System (INIS)

    Finkelstein, D.

    1989-01-01

    The quantum net unifies the basic principles of quantum theory and relativity in a quantum spacetime having no ultraviolet infinities, supporting the Dirac equation, and having the usual vacuum as a quantum condensation. A correspondence principle connects nets to Schwinger sources and further unifies the vertical structure of the theory, so that the functions of the many hierarchic levels of quantum field theory (predicate algebra, set theory, topology,hor-ellipsis, quantum dynamics) are served by one in quantum net dynamics

  16. Programming NET Web Services

    CERN Document Server

    Ferrara, Alex

    2007-01-01

    Web services are poised to become a key technology for a wide range of Internet-enabled applications, spanning everything from straight B2B systems to mobile devices and proprietary in-house software. While there are several tools and platforms that can be used for building web services, developers are finding a powerful tool in Microsoft's .NET Framework and Visual Studio .NET. Designed from scratch to support the development of web services, the .NET Framework simplifies the process--programmers find that tasks that took an hour using the SOAP Toolkit take just minutes. Programming .NET

  17. Game Coloured Petri Nets

    DEFF Research Database (Denmark)

    Westergaard, Michael

    2006-01-01

    This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachability...... analysis of this net class, and an application of game coloured Petri nets to automatically generate easy-to-understand visualizations of the model by exploiting the knowledge that some parts of the model are not interesting from a visualization perspective (i.e. they are part of the environment...

  18. Virtual Workshop

    DEFF Research Database (Denmark)

    Buus, Lillian; Bygholm, Ann

    In relation to the Tutor course in the Mediterranean Virtual University (MVU) project, a virtual workshop “Getting experiences with different synchronous communication media, collaboration, and group work” was held with all partner institutions in January 2006. More than 25 key-tutors within MVU...

  19. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1991-01-01

    This paper describes how Coloured Petri Nets (CP-nets) have been developed — from being a promising theoretical model to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems (and other systems in which human beings and...

  20. Construction of monophase nets

    International Nuclear Information System (INIS)

    Suarez A, Jose Antonio

    1996-01-01

    The paper refers to the use of monophase loads in commercial residential urbanizations and in small industries, for this reason it is considered unnecessary the construction of three-phase nets. The author makes a historical recount of these nets in Bogota, his capacities, uses and energy savings

  1. Fusion through the NET

    International Nuclear Information System (INIS)

    Spears, B.

    1987-01-01

    The paper concerns the next generation of fusion machines which are intended to demonstrate the technical viability of fusion. In Europe, the device that will follow on from JET is known as NET - the Next European Torus. If the design programme for NET proceeds, Europe could start to build the machine in 1994. The present JET programme hopes to achieve breakeven in the early 1990's. NET hopes to reach ignition in the next century, and so lay the foundation for a demonstration reactor. A description is given of the technical specifications of the components of NET, including: the first wall, the divertors to protect the wall, the array of magnets that provide the fields containing the plasma, the superconducting magnets, and the shield of the machine. NET's research programme is briefly outlined, including the testing programme to optimise conditions in the machine to achieve ignition, and its safety work. (U.K.)

  2. Virtual Beach Manager Toolset

    Science.gov (United States)

    The Virtual Beach Manager Toolset (VB) is a set of decision support software tools developed to help local beach managers make decisions as to when beaches should be closed due to predicted high levels of water borne pathogens. The tools are being developed under the umbrella of...

  3. Model and calculations for net infiltration

    International Nuclear Information System (INIS)

    Childs, S.W.; Long, A.

    1992-01-01

    In this paper a conceptual model for calculating net infiltration is developed and implemented. It incorporates the following important factors: viability of climate for the next 10,000 years, areal viability of net infiltration, and important soil/plant factors that affect the soil water budget of desert soils. Model results are expressed in terms of occurrence probabilities for time periods. In addition the variability of net infiltration is demonstrated both for change with time and differences among three soil/hydrologic units present at the site modeled

  4. Net Zero Energy Buildings

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna; Bourrelle, Julien S.; Gustavsen, Arild

    2010-01-01

    and identify possible renewable energy supply options which may be considered in calculations. Finally, the gap between the methodology proposed by each organisation and their respective national building code is assessed; providing an overview of the possible changes building codes will need to undergo......The international cooperation project IEA SHC Task 40 / ECBCS Annex 52 “Towards Net Zero Energy Solar Buildings”, attempts to develop a common understanding and to set up the basis for an international definition framework of Net Zero Energy Buildings (Net ZEBs). The understanding of such buildings...

  5. Getting to Net Zero

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-01

    The technology necessary to build net zero energy buildings (NZEBs) is ready and available today, however, building to net zero energy performance levels can be challenging. Energy efficiency measures, onsite energy generation resources, load matching and grid interaction, climatic factors, and local policies vary from location to location and require unique methods of constructing NZEBs. It is recommended that Components start looking into how to construct and operate NZEBs now as there is a learning curve to net zero construction and FY 2020 is just around the corner.

  6. Pro NET Best Practices

    CERN Document Server

    Ritchie, Stephen D

    2011-01-01

    Pro .NET Best Practices is a practical reference to the best practices that you can apply to your .NET projects today. You will learn standards, techniques, and conventions that are sharply focused, realistic and helpful for achieving results, steering clear of unproven, idealistic, and impractical recommendations. Pro .NET Best Practices covers a broad range of practices and principles that development experts agree are the right ways to develop software, which includes continuous integration, automated testing, automated deployment, and code analysis. Whether the solution is from a free and

  7. Virtual Teams.

    Science.gov (United States)

    Geber, Beverly

    1995-01-01

    Virtual work teams scattered around the globe are becoming a feature of corporate workplaces. Although most people prefer face-to-face meetings and interactions, reality often requires telecommuting. (JOW)

  8. Virtual data

    International Nuclear Information System (INIS)

    Bjorklund, E.

    1993-01-01

    In the 1970's, when computers were memory limited, operating system designers created the concept of ''virtual memory'' which gave users the ability to address more memory than physically existed. In the 1990s, many large control systems have the potential for becoming data limited. We propose that many of the principles behind virtual memory systems (working sets, locality, caching, and clustering) can also be applied to data-limited systems - creating, in effect, ''virtual data systems.'' At the Los Alamos National Laboratory's Clinton P. Anderson Meson Physics Facility (LAMPF), we have applied these principles to a moderately sized (10,000 data points) data acquisition and control system. To test the principles, we measured the system's performance during tune-up, production, and maintenance periods. In this paper, we present a general discussion of the principles of a virtual data system along with some discussion of our own implementation and the results of our performance measurements

  9. Virtual Worlds for Virtual Organizing

    Science.gov (United States)

    Rhoten, Diana; Lutters, Wayne

    The members and resources of a virtual organization are dispersed across time and space, yet they function as a coherent entity through the use of technologies, networks, and alliances. As virtual organizations proliferate and become increasingly important in society, many may exploit the technical architecture s of virtual worlds, which are the confluence of computer-mediated communication, telepresence, and virtual reality originally created for gaming. A brief socio-technical history describes their early origins and the waves of progress followed by stasis that brought us to the current period of renewed enthusiasm. Examination of contemporary examples demonstrates how three genres of virtual worlds have enabled new arenas for virtual organizing: developer-defined closed worlds, user-modifiable quasi-open worlds, and user-generated open worlds. Among expected future trends are an increase in collaboration born virtually rather than imported from existing organizations, a tension between high-fidelity recreations of the physical world and hyper-stylized imaginations of fantasy worlds, and the growth of specialized worlds optimized for particular sectors, companies, or cultures.

  10. PhysioNet

    Data.gov (United States)

    U.S. Department of Health & Human Services — The PhysioNet Resource is intended to stimulate current research and new investigations in the study of complex biomedical and physiologic signals. It offers free...

  11. NetSig

    DEFF Research Database (Denmark)

    Horn, Heiko; Lawrence, Michael S; Chouinard, Candace R

    2018-01-01

    Methods that integrate molecular network information and tumor genome data could complement gene-based statistical tests to identify likely new cancer genes; but such approaches are challenging to validate at scale, and their predictive value remains unclear. We developed a robust statistic (Net......Sig) that integrates protein interaction networks with data from 4,742 tumor exomes. NetSig can accurately classify known driver genes in 60% of tested tumor types and predicts 62 new driver candidates. Using a quantitative experimental framework to determine in vivo tumorigenic potential in mice, we found that Net......Sig candidates induce tumors at rates that are comparable to those of known oncogenes and are ten-fold higher than those of random genes. By reanalyzing nine tumor-inducing NetSig candidates in 242 patients with oncogene-negative lung adenocarcinomas, we find that two (AKT2 and TFDP2) are significantly amplified...

  12. Net alkalinity and net acidity 2: Practical considerations

    Science.gov (United States)

    Kirby, C.S.; Cravotta, C.A.

    2005-01-01

    The pH, alkalinity, and acidity of mine drainage and associated waters can be misinterpreted because of the chemical instability of samples and possible misunderstandings of standard analytical method results. Synthetic and field samples of mine drainage having various initial pH values and concentrations of dissolved metals and alkalinity were titrated by several methods, and the results were compared to alkalinity and acidity calculated based on dissolved solutes. The pH, alkalinity, and acidity were compared between fresh, unoxidized and aged, oxidized samples. Data for Pennsylvania coal mine drainage indicates that the pH of fresh samples was predominantly acidic (pH 2.5-4) or near neutral (pH 6-7); ??? 25% of the samples had pH values between 5 and 6. Following oxidation, no samples had pH values between 5 and 6. The Standard Method Alkalinity titration is constrained to yield values >0. Most calculated and measured alkalinities for samples with positive alkalinities were in close agreement. However, for low-pH samples, the calculated alkalinity can be negative due to negative contributions by dissolved metals that may oxidize and hydrolyze. The Standard Method hot peroxide treatment titration for acidity determination (Hot Acidity) accurately indicates the potential for pH to decrease to acidic values after complete degassing of CO2 and oxidation of Fe and Mn, and it indicates either the excess alkalinity or that required for neutralization of the sample. The Hot Acidity directly measures net acidity (= -net alkalinity). Samples that had near-neutral pH after oxidation had negative Hot Acidity; samples that had pH mine drainage treatment can lead to systems with insufficient Alkalinity to neutralize metal and H+ acidity and is not recommended. The use of net alkalinity = -Hot Acidity titration is recommended for the planning of mine drainage treatment. The use of net alkalinity = (Alkalinitymeasured - Aciditycalculated) is recommended with some cautions

  13. Programming NET 35

    CERN Document Server

    Liberty, Jesse

    2009-01-01

    Bestselling author Jesse Liberty and industry expert Alex Horovitz uncover the common threads that unite the .NET 3.5 technologies, so you can benefit from the best practices and architectural patterns baked into the new Microsoft frameworks. The book offers a Grand Tour" of .NET 3.5 that describes how the principal technologies can be used together, with Ajax, to build modern n-tier and service-oriented applications. "

  14. NET SALARY ADJUSTMENT

    CERN Multimedia

    Finance Division

    2001-01-01

    On 15 June 2001 the Council approved the correction of the discrepancy identified in the net salary adjustment implemented on 1st January 2001 by retroactively increasing the scale of basic salaries to achieve the 2.8% average net salary adjustment approved in December 2000. We should like to inform you that the corresponding adjustment will be made to your July salary. Full details of the retroactive adjustments will consequently be shown on your pay slip.

  15. RPV-1: A Virtual Test Reactor to simulate irradiation effects in light water reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Jumel, Stephanie; Van-Duysen, Jean Claude

    2005-01-01

    Many key components in commercial nuclear reactors are subject to neutron irradiation which modifies their mechanical properties. So far, the prediction of the in-service behavior and the lifetime of these components has required irradiations in so-called 'Experimental Test Reactors'. This predominantly empirical approach can now be supplemented by the development of physically based computer tools to simulate irradiation effects numerically. The devising of such tools, also called Virtual Test Reactors (VTRs), started in the framework of the REVE Project (REactor for Virtual Experiments). This project is a joint effort among Europe, the United States and Japan aimed at building VTRs able to simulate irradiation effects in pressure vessel steels and internal structures of LWRs. The European team has already built a first VTR, called RPV-1, devised for pressure vessel steels. Its inputs and outputs are similar to those of experimental irradiation programs carried out to assess the in-service behavior of reactor pressure vessels. RPV-1 is made of five codes and two databases which are linked up so as to receive, treat and/or convey data. A user friendly Python interface eases the running of the simulations and the visualization of the results. RPV-1 is sensitive to its inputs (neutron spectrum, temperature, ...) and provides results in conformity with experimental ones. The iterative improvement of RPV-1 has been started by the comparison of simulation results with the database of the IVAR experimental program led by the University of California Santa Barbara. These first successes led 40 European organizations to start developing RPV-2, an advanced version of RPV-1, as well as INTERN-1, a VTR devised to simulate irradiation effects in stainless steels, in a large effort (the PERFECT project) supported by the European Commission in the framework of the 6th Framework Program

  16. Development of a real-time method for the measurement of sulfur(IV) in cloud water with a counter-flow virtual impactor

    International Nuclear Information System (INIS)

    Dixon, R.W.

    1991-01-01

    A novel method, using a counter-flow virtual impactor (CVI) to measure S(IV) concentrations in cloud water, is described. The CVI collects and evaporates cloud droplets, converting aqueous S(IV) into gaseous SO 2 for analysis with a pulsed-fluorescence detector. Based on calculations and laboratory experiments with acidic droplets, S(IV), except that complexed as hydroxymethanesulfonate (HMS), is expected to be released to the gas phase during droplet evaporation. Evidence for the production of HMS in aerosol particles following droplet evaporation also was obtained from measurements of complexes S(IV) in ambient aerosol samples. Field measurements were performed with a CVI mounted on a research aircraft during the Frontal Boundary Study in Ohio to evaluate the CVI for measuring S(IV) in cloud water. From the signal of the SO 2 analyzer, the aqueous S(IV) concentration was determined. Measurements in clouds showed similar temporal variation of S(IV) (aq) with other cloud parameters following required data treatment. A detection limit of 0.1 nmol per m 3 of air was achieved over one minute intervals and was limited mainly by the noise of the SO 2 analyzer. Determination of molar S(IV) (aq) concentrations requires simultaneous measurements of the water vapor released by the evaporated droplets collected by the CVI which was not made

  17. Docking ligands into flexible and solvated macromolecules. 7. Impact of protein flexibility and water molecules on docking-based virtual screening accuracy.

    Science.gov (United States)

    Therrien, Eric; Weill, Nathanael; Tomberg, Anna; Corbeil, Christopher R; Lee, Devin; Moitessier, Nicolas

    2014-11-24

    The use of predictive computational methods in the drug discovery process is in a state of continual growth. Over the last two decades, an increasingly large number of docking tools have been developed to identify hits or optimize lead molecules through in-silico screening of chemical libraries to proteins. In recent years, the focus has been on implementing protein flexibility and water molecules. Our efforts led to the development of Fitted first reported in 2007 and further developed since then. In this study, we wished to evaluate the impact of protein flexibility and occurrence of water molecules on the accuracy of the Fitted docking program to discriminate active compounds from inactive compounds in virtual screening (VS) campaigns. For this purpose, a total of 171 proteins cocrystallized with small molecules representing 40 unique enzymes and receptors as well as sets of known ligands and decoys were selected from the Protein Data Bank (PDB) and the Directory of Useful Decoys (DUD), respectively. This study revealed that implementing displaceable crystallographic or computationally placed particle water molecules and protein flexibility can improve the enrichment in active compounds. In addition, an informed decision based on library diversity or research objectives (hit discovery vs lead optimization) on which implementation to use may lead to significant improvements.

  18. Virtual Vision

    Science.gov (United States)

    Terzopoulos, Demetri; Qureshi, Faisal Z.

    Computer vision and sensor networks researchers are increasingly motivated to investigate complex multi-camera sensing and control issues that arise in the automatic visual surveillance of extensive, highly populated public spaces such as airports and train stations. However, they often encounter serious impediments to deploying and experimenting with large-scale physical camera networks in such real-world environments. We propose an alternative approach called "Virtual Vision", which facilitates this type of research through the virtual reality simulation of populated urban spaces, camera sensor networks, and computer vision on commodity computers. We demonstrate the usefulness of our approach by developing two highly automated surveillance systems comprising passive and active pan/tilt/zoom cameras that are deployed in a virtual train station environment populated by autonomous, lifelike virtual pedestrians. The easily reconfigurable virtual cameras distributed in this environment generate synthetic video feeds that emulate those acquired by real surveillance cameras monitoring public spaces. The novel multi-camera control strategies that we describe enable the cameras to collaborate in persistently observing pedestrians of interest and in acquiring close-up videos of pedestrians in designated areas.

  19. Virtual Sustainability

    Directory of Open Access Journals (Sweden)

    William Sims Bainbridge

    2010-09-01

    Full Text Available In four ways, massively multiplayer online role-playing games may serve as tools for advancing sustainability goals, and as laboratories for developing alternatives to current social arrangements that have implications for the natural environment. First, by moving conspicuous consumption and other usually costly status competitions into virtual environments, these virtual worlds might reduce the need for physical resources. Second, they provide training that could prepare individuals to be teleworkers, and develop or demonstrate methods for using information technology to replace much transportation technology, notably in commuting. Third, virtual worlds and online games build international cooperation, even blending national cultures, thereby inching us toward not only the world consciousness needed for international agreements about the environment, but also toward non-spatial government that cuts across archaic nationalisms. Finally, realizing the potential social benefits of this new technology may urge us to reconsider a number of traditional societal institutions.

  20. Virtual Tower

    International Nuclear Information System (INIS)

    Wayne, R.A.

    1997-01-01

    The primary responsibility of an intrusion detection system (IDS) operator is to monitor the system, assess alarms, and summon and coordinate the response team when a threat is acknowledged. The tools currently provided to the operator are somewhat limited: monitors must be switched, keystrokes must be entered to call up intrusion sensor data, and communication with the response force must be maintained. The Virtual tower is an operator interface assembled from low-cost commercial-off-the-shelf hardware and software; it enables large amounts of data to be displayed in a virtual manner that provides instant recognition for the operator and increases assessment accuracy in alarm annunciator and control systems. This is accomplished by correlating and fusing the data into a 360-degree visual representation that employs color, auxiliary attributes, video, and directional audio to prompt the operator. The Virtual Tower would be a valuable low-cost enhancement to existing systems

  1. Virtual care

    DEFF Research Database (Denmark)

    Kamp, Annette; Aaløkke Ballegaard, Stinne

    of retrenchment, promising better quality, empowerment of citizens and work that is smarter and more qualified. Through ethnographic field studies we study the introduction of virtual home care in Danish elderly care, focusing on the implications for relational work and care relations. Virtual home care entails...... the performance of specific home care services by means of video conversations rather than physical visits in the citizens’ homes. As scholars within the STS tradition maintain, technologies do not simply replace a human function; they rather transform care work, redistributing tasks between citizens, technology...... point out how issues of trust and surveillance, which are always negotiated in care relations, are in fact accentuated in this kind of virtual care work. Moreover, we stress that the contemporary institutional context, organization and time schedules have a vast impact on the practices developed....

  2. Virtual toolbox

    Science.gov (United States)

    Jacobus, Charles J.; Jacobus, Heidi N.; Mitchell, Brian T.; Riggs, A. J.; Taylor, Mark J.

    1993-04-01

    At least three of the five senses must be fully addressed in a successful virtual reality (VR) system. Sight, sound, and touch are the most critical elements for the creation of the illusion of presence. Since humans depend so much on sight to collect information about their environment, this area has been the focus of much of the prior art in virtual reality, however, it is also crucial that we provide facilities for force, torque, and touch reflection, and sound replay and 3-D localization. In this paper we present a sampling of hardware and software in the virtual environment maker's `toolbox' which can support rapidly building up of customized VR systems. We provide demonstrative examples of how some of the tools work and we speculate about VR applications and future technology needs.

  3. Improving Virtual Collaborative Learning through Canonical Action Research

    Science.gov (United States)

    Weber, Peter; Lehr, Christian; Gersch, Martin

    2014-01-01

    Virtual collaboration continues to gain in significance and is attracting attention also as virtual collaborative learning (VCL) in education. This paper addresses aspects of VCL that we identified as critical in a series of courses named "Net Economy": (1) technical infrastructure, (2) motivation and collaboration, and (3) assessment…

  4. A Tutoring Wizard Guiding Tutorial Work in the Virtual University.

    Science.gov (United States)

    Mittrach, Silke; Schlageter, Gunter

    The Virtual University is an Internet-based learning environment developed at the University of Hagen (Germany). Complex teaching activities based on new concepts integrating net-based communication and cooperation facilities take place in the Virtual University. Experiences show that there is a threshold, especially for tutors in non-computer…

  5. Virtual polytopes

    International Nuclear Information System (INIS)

    Panina, G Yu; Streinu, I

    2015-01-01

    Originating in diverse branches of mathematics, from polytope algebra and toric varieties to the theory of stressed graphs, virtual polytopes represent a natural algebraic generalization of convex polytopes. Introduced as elements of the Grothendieck group associated to the semigroup of convex polytopes, they admit a variety of geometrizations. The present survey connects the theory of virtual polytopes with other geometrical subjects, describes a series of geometrizations together with relations between them, and gives a selection of applications. Bibliography: 50 titles

  6. RPV-1: a first virtual reactor to simulate irradiation effects in light water reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Jumel, St.

    2005-01-01

    The presented work was aimed at building a first VTR (virtual test reactor) to simulate irradiation effects in pressure vessel steels of nuclear reactor. It mainly consisted in: - modeling the formation of the irradiation induced damage in such steels, as well as their plasticity behavior - selecting codes and models to carry out the simulations of the involved mechanisms. Since the main focus was to build a first tool (rather than a perfect tool), it was decided to use, as much as possible, existing codes and models in spite of their imperfections. - developing and parameterizing two missing codes: INCAS and DUPAIR. - proposing an architecture to link the selected codes and models. - constructing and validating the tool. RPV-1 is made of five codes and two databases which are linked up so as to receive, treat and/or transmit data. A user friendly Python interface facilitates the running of the simulations and the visualization of the results. RPV-1 relies on many simplifications and approximations and has to be considered as a prototype aimed at clearing the way. According to the functionalities targeted for RPV-1, the main weakness is a bad Ni and Mn sensitivity. However, the tool can already be used for many applications (understanding of experimental results, assessment of effects of material and irradiation conditions,....). (O.M.)

  7. Spring-summer net community production, new production, particle export and related water column biogeochemical processes in the marginal sea ice zone of the Western Antarctic Peninsula 2012-2014.

    Science.gov (United States)

    Ducklow, Hugh W; Stukel, Michael R; Eveleth, Rachel; Doney, Scott C; Jickells, Tim; Schofield, Oscar; Baker, Alex R; Brindle, John; Chance, Rosie; Cassar, Nicolas

    2018-06-28

    New production (New P, the rate of net primary production (NPP) supported by exogenously supplied limiting nutrients) and net community production (NCP, gross primary production not consumed by community respiration) are closely related but mechanistically distinct processes. They set the carbon balance in the upper ocean and define an upper limit for export from the system. The relationships, relative magnitudes and variability of New P (from 15 NO 3 - uptake), O 2  : argon-based NCP and sinking particle export (based on the 238 U :  234 Th disequilibrium) are increasingly well documented but still not clearly understood. This is especially true in remote regions such as polar marginal ice zones. Here we present a 3-year dataset of simultaneous measurements made at approximately 50 stations along the Western Antarctic Peninsula (WAP) continental shelf in midsummer (January) 2012-2014. Net seasonal-scale changes in water column inventories (0-150 m) of nitrate and iodide were also estimated at the same stations. The average daily rates based on inventory changes exceeded the shorter-term rate measurements. A major uncertainty in the relative magnitude of the inventory estimates is specifying the start of the growing season following sea-ice retreat. New P and NCP(O 2 ) did not differ significantly. New P and NCP(O 2 ) were significantly greater than sinking particle export from thorium-234. We suggest this is a persistent and systematic imbalance and that other processes such as vertical mixing and advection of suspended particles are important export pathways.This article is part of the theme issue 'The marine system of the west Antarctic Peninsula: status and strategy for progress in a region of rapid change'. © 2018 The Author(s).

  8. Biological Petri Nets

    CERN Document Server

    Wingender, E

    2011-01-01

    It was suggested some years ago that Petri nets might be well suited to modeling metabolic networks, overcoming some of the limitations encountered by the use of systems employing ODEs (ordinary differential equations). Much work has been done since then which confirms this and demonstrates the usefulness of this concept for systems biology. Petri net technology is not only intuitively understood by scientists trained in the life sciences, it also has a robust mathematical foundation and provides the required degree of flexibility. As a result it appears to be a very promising approach to mode

  9. Reconfiguration of distribution nets

    International Nuclear Information System (INIS)

    Latorre Bayona, Gerardo; Angarita Marquez, Jorge Luis

    2000-01-01

    Starting of the location of the reconfiguration problem inside the context of the operation of distribution nets, of the quality indicators definition and of the presentation of the alternatives more used for reduction of technical losses, they are related diverse reconfiguration methodologies proposed in the technical literature, pointing out their three principals limitations; also are presents the results of lost obtained starting from simulation works carried out in distribution circuits of the ESSA ESP, which permitting to postulate the reconfiguration of nets like an excellent alternative to reduce technical losses

  10. NET system integration

    International Nuclear Information System (INIS)

    Farfaletti-Casali, F.; Mitchell, N.; Salpietro, E.; Buzzi, U.; Gritzmann, P.

    1985-01-01

    The NET system integration procedure is the process by which the requirements of the various Tokamak machine design areas are brought together to form a compatible machine layout. Each design area produces requirements which generally allow components to be built at minimum cost and operate with minimum technical risk, and the final machine assembly should be achieved with minimum departure from these optimum designs. This is carried out in NET by allowing flexibility in the maintenance and access methods to the machine internal components which must be regularly replaced by remote handling, in segmentation of these internal components and in the number of toroidal field coils

  11. Combined chemical and toxicological long-term monitoring for AhR agonists with SPMD-based virtual organisms in drinking water Danjiangkou Reservoir, China.

    Science.gov (United States)

    Wang, Jingxian; Song, Guoqiang; Li, Aimin; Henkelmann, Bernhard; Pfister, Gerd; Tong, Anthony Z; Schramm, Karl-Werner

    2014-08-01

    SPMD-based virtual organisms (VOs) were employed for time-integrating, long-term sampling combined biological and chemical analyses for exposure assessment of hydrophobic organic pollutants (HOPs) in a drinking water reservoir, China. The SPMDs were deployed at four and five sites in the Danjiangkou (DJK) reservoir over two periods of 26 and 31 d to sequester the hydrophobic contaminants in water. The chosen bioassay response for the extracts of the SPMDs, the induction of 7-ethoxyresorufin-o-deethylase (EROD) was assayed using a rat hepatoma cell line (H4IIE). The known aryl hydrocarbon receptor (AhR) agonists PAHs and PCBs were analyzed by HRGC/HRMS instrument. The cause-effect relationship between the observed AhR activities and chemical concentrations of detected AhR agonists was examined. The results show that the extracts from the SPMD samples could induce AhR activity significantly, whereas the chemically derived 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalent (TEQcal) was not correlated with the bioassay-derived TCDD equivalent (TEQbio). The known AhR agonists could only account for 2-10% of the observed AhR responses among which the contribution of PCBs could almost be neglected. Unidentified AhR-active compounds represented a greater proportion of the TCDD equivalent (TCDD-EQ) in SPMD samples from DJK. Based on the first assessment, the VO followed by the combination of chemical and biological analyses emerges as a resource efficient water monitoring device in ecotoxicological assessment for toxicologically relevant compounds which are readily available for uptake by resident aquatic biota in drinking water resources. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Assessment on the net

    Directory of Open Access Journals (Sweden)

    Joaquín GARCÍA CARRASCO

    2016-03-01

    Full Text Available Evaluation assesses the teaching-learning process, so that there can not be teaching and learning if there are not some defined objectives to be assessed. Currently, there are many virtual learning environments developed, mainly supported by the web, but most of them do not incorporate evaluation modules. Besides, the lack of learning technology standards limits system interoperability and resource reuse.

  13. Netted LPI RADARs

    Science.gov (United States)

    2011-09-01

    CHALLENGES ............................66 1. Radar Processing Gain ........................66 2. High Sensitivity Requirement .................68 B...Relationship Between Network Space and Challenges .....................................127 Figure 42. Maneuverability................................129...virtually any kind of terrain. It has five modes: Normal, Weather, ECCM, LPI, and Very Low Clearance ( VLC ). Pictures of the LANTIRN pod aboard and F-16

  14. DeepNet: An Ultrafast Neural Learning Code for Seismic Imaging

    International Nuclear Information System (INIS)

    Barhen, J.; Protopopescu, V.; Reister, D.

    1999-01-01

    A feed-forward multilayer neural net is trained to learn the correspondence between seismic data and well logs. The introduction of a virtual input layer, connected to the nominal input layer through a special nonlinear transfer function, enables ultrafast (single iteration), near-optimal training of the net using numerical algebraic techniques. A unique computer code, named DeepNet, has been developed, that has achieved, in actual field demonstrations, results unattainable to date with industry standard tools

  15. Virtual Savannah

    DEFF Research Database (Denmark)

    Rodil, Kasper; Eskildsen, Søren; Rehm, Matthias

    2012-01-01

    Virtual Savannah is constructed to visualize parts of a curriculum, which the educational service at Aalborg Zoo has difficulties in teaching children visiting the zoo. It contains rich media like audio, text, video and picture galleries about African ecology, but some of this episodic information...

  16. Virtual Reality.

    Science.gov (United States)

    Newby, Gregory B.

    1993-01-01

    Discusses the current state of the art in virtual reality (VR), its historical background, and future possibilities. Highlights include applications in medicine, art and entertainment, science, business, and telerobotics; and VR for information science, including graphical display of bibliographic data, libraries and books, and cyberspace.…

  17. Virtualize Me!

    Science.gov (United States)

    Waters, John K.

    2009-01-01

    John Abdelmalak, director of technology for the School District of the Chathams, was pretty sure it was time to jump on the virtualization bandwagon last year when he invited Dell to conduct a readiness assessment of his district's servers. When he saw just how little of their capacity was being used, he lost all doubt. Abdelmalak is one of many…

  18. Virtual Classroom

    DEFF Research Database (Denmark)

    Christensen, Ove

    2013-01-01

    In the Scandinavian countries: Sweden, Norway and Denmark, the project GNU (Grænseoverskridende Nordisk Undervisning, i.e. Transnational Nordic Teaching) is experimenting with ways of conducting teaching across the borders in the elementary schools. The cloud classes are organised with one class...... and benefits in regard to learning and pedagogy with virtual classroom....

  19. Virtual landmarks

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Odhner, Dewey; Bai, Peirui; Torigian, Drew A.

    2017-03-01

    Much has been published on finding landmarks on object surfaces in the context of shape modeling. While this is still an open problem, many of the challenges of past approaches can be overcome by removing the restriction that landmarks must be on the object surface. The virtual landmarks we propose may reside inside, on the boundary of, or outside the object and are tethered to the object. Our solution is straightforward, simple, and recursive in nature, proceeding from global features initially to local features in later levels to detect landmarks. Principal component analysis (PCA) is used as an engine to recursively subdivide the object region. The object itself may be represented in binary or fuzzy form or with gray values. The method is illustrated in 3D space (although it generalizes readily to spaces of any dimensionality) on four objects (liver, trachea and bronchi, and outer boundaries of left and right lungs along pleura) derived from 5 patient computed tomography (CT) image data sets of the thorax and abdomen. The virtual landmark identification approach seems to work well on different structures in different subjects and seems to detect landmarks that are homologously located in different samples of the same object. The approach guarantees that virtual landmarks are invariant to translation, scaling, and rotation of the object/image. Landmarking techniques are fundamental for many computer vision and image processing applications, and we are currently exploring the use virtual landmarks in automatic anatomy recognition and object analytics.

  20. A virtual water maze revisited: Two-year changes in navigation performance and their neural correlates in healthy adults.

    Science.gov (United States)

    Daugherty, Ana M; Raz, Naftali

    2017-02-01

    Age-related declines in spatial navigation are associated with deficits in procedural and episodic memory and deterioration of their neural substrates. For the lack of longitudinal evidence, the pace and magnitude of these declines and their neural mediators remain unclear. Here we examined virtual navigation in healthy adults (N=213, age 18-77 years) tested twice, two years apart, with complementary indices of navigation performance (path length and complexity) measured over six learning trials at each occasion. Slopes of skill acquisition curves and longitudinal change therein were estimated in structural equation modeling, together with change in regional brain volumes and iron content (R2* relaxometry). Although performance on the first trial did not differ between occasions separated by two years, the slope of path length improvement over trials was shallower and end-of-session performance worse at follow-up. Advanced age, higher pulse pressure, smaller cerebellar and caudate volumes, and greater caudate iron content were associated with longer search paths, i.e. poorer navigation performance. In contrast, path complexity diminished faster over trials at follow-up, albeit less so in older adults. Improvement in path complexity after two years was predicted by lower baseline hippocampal iron content and larger parahippocampal volume. Thus, navigation path length behaves as an index of perceptual-motor skill that is vulnerable to age-related decline, whereas path complexity may reflect cognitive mapping in episodic memory that improves with repeated testing, although not enough to overcome age-related deficits. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Personal Virtual Libraries

    Science.gov (United States)

    Pappas, Marjorie L.

    2004-01-01

    Virtual libraries are becoming more and more common. Most states have a virtual library. A growing number of public libraries have a virtual presence on the Web. Virtual libraries are a growing addition to school library media collections. The next logical step would be personal virtual libraries. A personal virtual library (PVL) is a collection…

  2. Coloured Petri Nets

    CERN Document Server

    Jensen, Kurt

    2009-01-01

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. This book introduces the constructs of the CPN modelling language and presents the related analysis methods. It provides a comprehensive road map for the practical use of CPN.

  3. Safety nets or straitjackets?

    DEFF Research Database (Denmark)

    Ilsøe, Anna

    2012-01-01

    Does regulation of working hours at national and sector level impose straitjackets, or offer safety nets to employees seeking working time flexibility? This article compares legislation and collective agreements in the metal industries of Denmark, Germany and the USA. The industry has historically...

  4. Neuronal nets in robotics

    International Nuclear Information System (INIS)

    Jimenez Sanchez, Raul

    1999-01-01

    The paper gives a generic idea of the solutions that the neuronal nets contribute to the robotics. The advantages and the inconveniences are exposed that have regarding the conventional techniques. It also describe the more excellent applications as the pursuit of trajectories, the positioning based on images, the force control or of the mobile robots management, among others

  5. Net4Care platform

    DEFF Research Database (Denmark)

    2012-01-01

    , that in turn enables general practitioners and clinical staff to view observations. Use the menus above to explore the site's information resources. To get started, follow the short Hello, World! tutorial. The Net4Care project is funded by The Central Denmark Region and EU via Caretech Innovation....

  6. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Kristensen, Lars Michael

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. The development of such systems is particularly challenging because of inherent intricacies like possible nondeterminism an...

  7. Game Theory .net.

    Science.gov (United States)

    Shor, Mikhael

    2003-01-01

    States making game theory relevant and accessible to students is challenging. Describes the primary goal of GameTheory.net is to provide interactive teaching tools. Indicates the site strives to unite educators from economics, political and computer science, and ecology by providing a repository of lecture notes and tests for courses using…

  8. BacillusRegNet

    DEFF Research Database (Denmark)

    Misirli, Goksel; Hallinan, Jennifer; Röttger, Richard

    2014-01-01

    As high-throughput technologies become cheaper and easier to use, raw sequence data and corresponding annotations for many organisms are becoming available. However, sequence data alone is not sufficient to explain the biological behaviour of organisms, which arises largely from complex molecular...... the associated BacillusRegNet website (http://bacillus.ncl.ac.uk)....

  9. Boom Booom Net Radio

    DEFF Research Database (Denmark)

    Grimshaw, Mark Nicholas; Yong, Louisa; Dobie, Ian

    1999-01-01

    of an existing Internet radio station; Boom Booom Net Radio. Whilst necessity dictates some use of technology-related terminology, wherever possible we have endeavoured to keep such jargon to a minimum and to either explain it in the text or to provide further explanation in the appended glossary....

  10. Evaluation of water balance parameters from isotopic measurements in evaporation pans

    International Nuclear Information System (INIS)

    Allison, G.B.

    1979-01-01

    The evaluation of the parameters governing the isotopic composition of evaporating water bodies was attempted by means of evaporation pans. The instability of the meteorological conditions, however, makes it virtually impossible to evaluate the atmospheric relative humidity and its isotopic composition with pans. Pans are only suitable to obtain seasonal trends of the isotopic composition of the net evaporated water. For this, a technique based on two pans is also proposed. (author)

  11. Sensorial Virtualization: Coupling Gaming and Virtual Environment

    NARCIS (Netherlands)

    Garbaya, S.; Miraoui, C.; Wendrich, Robert E.; Lim, T.; Stanescu, I.A.; Hauge, J.B.

    2014-01-01

    Virtual reality and virtualization are currently used to design complex systems and demonstrate that they represent the functionalities of real systems. However, the design refinement of the virtual environment (VE) and distributed virtual environment (DVE) are still time consuming and costly, as it

  12. Virtual Presenters: Towards Interactive Virtual Presentations

    NARCIS (Netherlands)

    Nijholt, Antinus; Cappellini, V.; Hemsley, J.

    2005-01-01

    We discuss having virtual presenters in virtual environments that present information to visitors of these environments. Some current research is surveyed and we will look in particular to our research in the context of a virtual meeting room where a virtual presenter uses speech, gestures, pointing

  13. Virtual materiality

    DEFF Research Database (Denmark)

    Søndergaard, Dorte Marie

    as their recounts of them and 3. the consumption of other media products like movies, reality shows, YouTube videos etc. How do we theorize ‘matter’ in such dimensions? Is it possible to theorize virtual matter as ‘materiality’ in line with any real life materiality? What conceptualization will help us understand......? These questions become crucial when we follow matter in and across real life, virtual experience, recounted imagery, night dreams, YouTube videos and even further. Some may already have recognized Phillip’s skeleton army as a transport/transformation from Lord of the Rings, DVD 3, the army which Aragon calls out....... Butler, J. (1993) Bodies that Matter. On the Discursive Limits of “Sex”. London: Routledge. Durkin, K. et al. (1998) Children, Media and Agression. Current Research in Australia and New Zealand. In: Carlson, U. & von Feilitzen, C. (red): Children and Media Violence. Yearbook from the UNESCO International...

  14. Virtual anthropology.

    Science.gov (United States)

    Weber, Gerhard W

    2015-02-01

    Comparative morphology, dealing with the diversity of form and shape, and functional morphology, the study of the relationship between the structure and the function of an organism's parts, are both important subdisciplines in biological research. Virtual anthropology (VA) contributes to comparative morphology by taking advantage of technological innovations, and it also offers new opportunities for functional analyses. It exploits digital technologies and pools experts from different domains such as anthropology, primatology, medicine, paleontology, mathematics, statistics, computer science, and engineering. VA as a technical term was coined in the late 1990s from the perspective of anthropologists with the intent of being mostly applied to biological questions concerning recent and fossil hominoids. More generally, however, there are advanced methods to study shape and size or to manipulate data digitally suitable for application to all kinds of primates, mammals, other vertebrates, and invertebrates or to issues regarding plants, tools, or other objects. In this sense, we could also call the field "virtual morphology." The approach yields permanently available virtual copies of specimens and data that comprehensively quantify geometry, including previously neglected anatomical regions. It applies advanced statistical methods, supports the reconstruction of specimens based on reproducible manipulations, and promotes the acquisition of larger samples by data sharing via electronic archives. Finally, it can help identify new, hidden traits, which is particularly important in paleoanthropology, where the scarcity of material demands extracting information from fragmentary remains. This contribution presents a current view of the six main work steps of VA: digitize, expose, compare, reconstruct, materialize, and share. The VA machinery has also been successfully used in biomechanical studies which simulate the stress and strains appearing in structures. Although

  15. Virtual automation.

    Science.gov (United States)

    Casis, E; Garrido, A; Uranga, B; Vives, A; Zufiaurre, C

    2001-01-01

    Total laboratory automation (TLA) can be substituted in mid-size laboratories by a computer sample workflow control (virtual automation). Such a solution has been implemented in our laboratory using PSM, software developed in cooperation with Roche Diagnostics (Barcelona, Spain), to this purpose. This software is connected to the online analyzers and to the laboratory information system and is able to control and direct the samples working as an intermediate station. The only difference with TLA is the replacement of transport belts by personnel of the laboratory. The implementation of this virtual automation system has allowed us the achievement of the main advantages of TLA: workload increase (64%) with reduction in the cost per test (43%), significant reduction in the number of biochemistry primary tubes (from 8 to 2), less aliquoting (from 600 to 100 samples/day), automation of functional testing, drastic reduction of preanalytical errors (from 11.7 to 0.4% of the tubes) and better total response time for both inpatients (from up to 48 hours to up to 4 hours) and outpatients (from up to 10 days to up to 48 hours). As an additional advantage, virtual automation could be implemented without hardware investment and significant headcount reduction (15% in our lab).

  16. Virtual Cystoscopy

    International Nuclear Information System (INIS)

    Mejia Restrepo, Jorge; Aldana S, Natalia; Munoz Sierra, Juan; Lopez Amaya, Juan

    2011-01-01

    Introduction: virtual cystoscopy is a minimally invasive procedure that facilitates the evaluation of the urinary tract, allowing intraluminal navigation through the urinary tract structures on the basis of CT imaging reconstructions. it allows detection of various pathologies of the system, through high-sensitivity, three-dimensional lesion visualization with some advantages over conventional cystoscopy. Objective: to describe the technique used for virtual cystoscopy at our institution,and present some representative cases. Materials and methods: We describe the main indications, advantages and limitations of the method, followed by a description of the technique used in our institution, and finally, we present five representative cases of bladder and urethral pathology. Conclusion: virtual cystoscopy is a sensitive technique for the diagnosis of bladder tumors, even those smaller than 5mm. it is the preferred method in patients who have contraindications for conventional cystoscopy, such as prostate hyperplasia, urethral stenoses and active haematuria.it is less invasive and has a lower complication rate when compared with conventional cystoscopy. It has limited use in the assessment of the mucosa and of small, flat lesions.

  17. SolNet

    DEFF Research Database (Denmark)

    Jordan, Ulrike; Vajen, Klaus; Bales, Chris

    2014-01-01

    -accompanying Master courses, placements of internships, and PhD scholarship projects. A new scholarship project, “SHINE”, was launched in autumn 2013 in the frame work of the Marie Curie program of the European Union (Initial Training Network, ITN). 13 PhD-scholarships on solar district heating, solar heat......SolNet, founded in 2006, is the first coordinated International PhD education program on Solar Thermal Engineering. The SolNet network is coordinated by the Institute of Thermal Engineering at Kassel University, Germany. The network offers PhD courses on solar heating and cooling, conference...... for industrial processes, as well as sorption stores and materials started in December 2013. Additionally, the project comprises a training program with five PhD courses and several workshops on solar thermal engineering that will be open also for other PhD students working in the field. The research projects...

  18. Turkey's net energy consumption

    International Nuclear Information System (INIS)

    Soezen, Adnan; Arcaklioglu, Erol; Oezkaymak, Mehmet

    2005-01-01

    The main goal of this study is to develop the equations for forecasting net energy consumption (NEC) using an artificial neural-network (ANN) technique in order to determine the future level of energy consumption in Turkey. In this study, two different models were used in order to train the neural network. In one of them, population, gross generation, installed capacity and years are used in the input layer of the network (Model 1). Other energy sources are used in input layer of network (Model 2). The net energy consumption is in the output layer for two models. Data from 1975 to 2003 are used for the training. Three years (1981, 1994 and 2003) are used only as test data to confirm this method. The statistical coefficients of multiple determinations (R 2 -value) for training data are equal to 0.99944 and 0.99913 for Models 1 and 2, respectively. Similarly, R 2 values for testing data are equal to 0.997386 and 0.999558 for Models 1 and 2, respectively. According to the results, the net energy consumption using the ANN technique has been predicted with acceptable accuracy. Apart from reducing the whole time required, with the ANN approach, it is possible to find solutions that make energy applications more viable and thus more attractive to potential users. It is also expected that this study will be helpful in developing highly applicable energy policies

  19. Net one, net two: the primary care network income statement.

    Science.gov (United States)

    Halley, M D; Little, A W

    1999-10-01

    Although hospital-owned primary care practices have been unprofitable for most hospitals, some hospitals are achieving competitive advantage and sustainable practice operations. A key to the success of some has been a net income reporting tool that separates practice operating expenses from the costs of creating and operating a network of practices to help healthcare organization managers, physicians, and staff to identify opportunities to improve the network's financial performance. This "Net One, Net Two" reporting allows operations leadership to be held accountable for Net One expenses and strategic leadership to be held accountable for Net Two expenses.

  20. Proof Nets for Lambek Calculus

    NARCIS (Netherlands)

    Roorda, Dirk

    1992-01-01

    The proof nets of linear logic are adapted to the non-commutative Lambek calculus. A different criterion for soundness of proof nets is given, which gives rise to new algorithms for proof search. The order sensitiveness of the Lambek calculus is reflected by the planarity condition on proof nets;

  1. Net metering: zero electricity bill

    International Nuclear Information System (INIS)

    Mangi, A.; Khan, Z.

    2011-01-01

    Worldwide move towards renewable energy sources, environmental concerns and decentralization of the power sector have made net metering an attractive option for power generation at small scale. This paper discusses the net metering, economical issues of renewable sources in Pakistan, technical aspects, installation suitability according to varying terrain, existing utility rules and formulation of legislation for net metering making it economically attractive. (author)

  2. The Net Advance of Physics

    Science.gov (United States)

    THE NET ADVANCE OF PHYSICS Review Articles and Tutorials in an Encyclopædic Format Established 1995 [Link to MIT] Computer support for The Net Advance of Physics is furnished by The Massachusetts Newest Additions SPECIAL FEATURES: Net Advance RETRO: Nineteenth Century Physics History of Science

  3. Periodismo virtual

    Directory of Open Access Journals (Sweden)

    Carlos Morales

    2015-01-01

    Full Text Available El periodismo virtual se produce en diarios que no ofrecen noticias (concebidas como versión o reflejo de la realidad sino que crean sus propias ficciones, especialmente en primeras planas. El autor del artículo señala que esto esta sucediendo en LA NACIÓN de San José de Costa Rica, diario premiado por la inefable Sociedad Interamericana de Prensa - SIP - y periódico económicamente más importante del país.

  4. Master Robotic Net

    Directory of Open Access Journals (Sweden)

    Vladimir Lipunov

    2010-01-01

    Full Text Available The main goal of the MASTER-Net project is to produce a unique fast sky survey with all sky observed over a single night down to a limiting magnitude of 19-20. Such a survey will make it possible to address a number of fundamental problems: search for dark energy via the discovery and photometry of supernovae (including SNIa, search for exoplanets, microlensing effects, discovery of minor bodies in the Solar System, and space-junk monitoring. All MASTER telescopes can be guided by alerts, and we plan to observe prompt optical emission from gamma-ray bursts synchronously in several filters and in several polarization planes.

  5. Limitations of shallow nets approximation.

    Science.gov (United States)

    Lin, Shao-Bo

    2017-10-01

    In this paper, we aim at analyzing the approximation abilities of shallow networks in reproducing kernel Hilbert spaces (RKHSs). We prove that there is a probability measure such that the achievable lower bound for approximating by shallow nets can be realized for all functions in balls of reproducing kernel Hilbert space with high probability, which is different with the classical minimax approximation error estimates. This result together with the existing approximation results for deep nets shows the limitations for shallow nets and provides a theoretical explanation on why deep nets perform better than shallow nets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Environmental impact analysis of aquaculture in net cages in a ...

    African Journals Online (AJOL)

    Environmental impact analysis of aquaculture in net cages in a Brazilian water reservoir, based in zooplankton communities. Maria Cristina Crispim, Karla Patrícia Ponte Araújo, Hênio do Nascimento Melo Júnior ...

  7. Shielding calculations for NET

    International Nuclear Information System (INIS)

    Verschuur, K.A.; Hogenbirk, A.

    1991-05-01

    In the European Fusion Technology Programme there is only a small activity on research and development for fusion neutronics. Never-the-less, looking further than blanket design now, as ECN is getting involved in design of radiation shields for the coils and biological shields, it becomes apparent that fusion neutronics as a whole still needs substantial development. Existing exact codes for calculation of complex geometries like MCNP and DORT/TORT are put over the limits of their numerical capabilities, whilst approximate codes for complex geometries like FURNACE and MERCURE4 are put over the limits of their modelling capabilities. The main objective of this study is just to find out how far we can get with existing codes in obtaining reliable values for the radiation levels inside and outside the cryostat/shield during operation and after shut-down. Starting with a 1D torus model for preliminary parametric studies, more dimensional approximation of the torus or parts of it including the main heterogeneities should follow. Regular contacts with the NET-Team are kept, to be aware of main changes in NET design that might affect our calculation models. Work on the contract started 1 July 1990. The technical description of the contract is given. (author). 14 refs.; 4 figs.; 1 tab

  8. Trust and virtual worlds

    DEFF Research Database (Denmark)

    Ess, Charles; Thorseth, May

    2011-01-01

    We collect diverse philosophical analyses of the issues and problems clustering around trust online with specific attention to establishing trust in virtual environments. The book moves forward important discussions of how virtual worlds and virtuality are to be defined and understood; the role o...... by virtuality, such as virtual child pornography. The introduction further develops a philosophical anthropology, rooted in Kantian ethics, phenomenology, virtue ethics, and feminist perspectives, that grounds a specific approach to ethical issues in virtual environments....

  9. Realidad virtual y materialidad

    OpenAIRE

    Pérez Herranz, Fernando Miguel

    2009-01-01

    1. Fenomenología de partida: Real / Simbólico / Imaginario 2. Realidad 3. Virtual 3.1. Virtual / real / posible / probable 3.2. Los contextos de la realidad virtual A) REALIDAD VIRTUAL INMERSIVA B) REALIDAD VIRTUAL NO INMERSIVA C) REALIDAD VIRTUAL Y DIGITALIZACIÓN 3.3. Cruce virtual / real 3.4. Cuestiones filosóficas 4. Materialidad 5. Materialidad y descentramiento 5.1. Ejemplos de descentramiento en los contextos de Realidad Virtual A’) DUALISMO CARTESIANO, CUERPO Y «CIBORG » B’) EL ESPÍRIT...

  10. NETS - Danish participation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Alsen, S. (Grontmij - Carl Bro, Glostrup (Denmark)); Theel, C. (Baltic Sea Solutions, Holeby (Denmark))

    2008-12-15

    Within the NICe-funded project 'Nordic Environmental Technology Solutions (NETS)' a new type of networking at the Nordic level was organized in order to jointly exploit the rapidly growing market potential in the environmental technology sector. The project aimed at increased and professionalized commercialization of Nordic Cleantech in energy and water business segments through 1) closer cooperation and joint marketing activities, 2) a website, 3) cleantech product information via brochures and publications 4) and participating in relevant trade fairs and other industry events. Facilitating business-to-business activities was another core task for the NETS project partners from Norway, Sweden, Finland and Denmark with the aim to encourage total solutions for combined Cleantech system offers. The project has achieved to establish a Cleantech register of 600 Nordic Cleantech companies, a network of 86 member enterprises, produced several publications and brochures for direct technology promotion and a website for direct access to company profiles and contact data. The project partners have attended 14 relevant international Cleantech trade fairs and conferences and facilitated business-to-business contacts added by capacity building offers through two company workshops. The future challenge for the project partners and Nordic Cleantech will be to coordinate the numerous efforts within the Nordic countries in order to reach concerted action and binding of member companies for reliable services, an improved visibility and knowledge exchange. With Cleantech's growing market influence and public awareness, the need to develop total solutions is increasing likewise. Marketing efforts should be encouraged cross-sectional and cross-border among the various levels of involved actors from both the public and the private sector. (au)

  11. NETS - Danish participation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Alsen, S [Grontmij - Carl Bro, Glostrup (Denmark); Theel, C [Baltic Sea Solutions, Holeby (Denmark)

    2008-12-15

    Within the NICe-funded project 'Nordic Environmental Technology Solutions (NETS)' a new type of networking at the Nordic level was organized in order to jointly exploit the rapidly growing market potential in the environmental technology sector. The project aimed at increased and professionalized commercialization of Nordic Cleantech in energy and water business segments through 1) closer cooperation and joint marketing activities, 2) a website, 3) cleantech product information via brochures and publications 4) and participating in relevant trade fairs and other industry events. Facilitating business-to-business activities was another core task for the NETS project partners from Norway, Sweden, Finland and Denmark with the aim to encourage total solutions for combined Cleantech system offers. The project has achieved to establish a Cleantech register of 600 Nordic Cleantech companies, a network of 86 member enterprises, produced several publications and brochures for direct technology promotion and a website for direct access to company profiles and contact data. The project partners have attended 14 relevant international Cleantech trade fairs and conferences and facilitated business-to-business contacts added by capacity building offers through two company workshops. The future challenge for the project partners and Nordic Cleantech will be to coordinate the numerous efforts within the Nordic countries in order to reach concerted action and binding of member companies for reliable services, an improved visibility and knowledge exchange. With Cleantech's growing market influence and public awareness, the need to develop total solutions is increasing likewise. Marketing efforts should be encouraged cross-sectional and cross-border among the various levels of involved actors from both the public and the private sector. (au)

  12. The equivalency between logic Petri workflow nets and workflow nets.

    Science.gov (United States)

    Wang, Jing; Yu, ShuXia; Du, YuYue

    2015-01-01

    Logic Petri nets (LPNs) can describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. Logic Petri workflow nets (LPWNs) are proposed based on LPNs in this paper. Process mining is regarded as an important bridge between modeling and analysis of data mining and business process. Workflow nets (WF-nets) are the extension to Petri nets (PNs), and have successfully been used to process mining. Some shortcomings cannot be avoided in process mining, such as duplicate tasks, invisible tasks, and the noise of logs. The online shop in electronic commerce in this paper is modeled to prove the equivalence between LPWNs and WF-nets, and advantages of LPWNs are presented.

  13. The Equivalency between Logic Petri Workflow Nets and Workflow Nets

    Science.gov (United States)

    Wang, Jing; Yu, ShuXia; Du, YuYue

    2015-01-01

    Logic Petri nets (LPNs) can describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. Logic Petri workflow nets (LPWNs) are proposed based on LPNs in this paper. Process mining is regarded as an important bridge between modeling and analysis of data mining and business process. Workflow nets (WF-nets) are the extension to Petri nets (PNs), and have successfully been used to process mining. Some shortcomings cannot be avoided in process mining, such as duplicate tasks, invisible tasks, and the noise of logs. The online shop in electronic commerce in this paper is modeled to prove the equivalence between LPWNs and WF-nets, and advantages of LPWNs are presented. PMID:25821845

  14. Realidad virtual

    OpenAIRE

    García García, Alberto Luis

    2000-01-01

    Las nuevas tecnologías, basadas en el mundo digital propuesto por la informática, están cambiando nuestra forma de entender el mundo, tanto desde el punto de vista sociocultural como económico. La realidad virtual se vale de códigos icónicos, y con ello se convierte en un paso más hacia la supresión de toda barrera linguística, para llegar a conseguir la gran comunidad global. Es necesario conocer en toda su extensión, una tecnología que está cambiando el modo de comunicarnos. Estos son, a gr...

  15. Virtual Reality and the Virtual Library.

    Science.gov (United States)

    Oppenheim, Charles

    1993-01-01

    Explains virtual reality, including proper and improper uses of the term, and suggests ways that libraries might be affected by it. Highlights include elements of virtual reality systems; possible virtual reality applications, including architecture, the chemical industry, transport planning, armed forces, and entertainment; and the virtual…

  16. From virtual environment to virtual community

    NARCIS (Netherlands)

    Nijholt, Antinus; Terano, Takao; Nishida, Toyoaki; Namatame, Akira; Tsumoto, Syusaku; Ohsawa, Yukido; Washio, Takashi

    2001-01-01

    We discuss a virtual reality theater environment and its transition to a virtual community by adding domain agents and by allowing multiple users to visit this environment. The environment has been built using VRML (Virtual Reality Modeling Language). We discuss how our ideas about this environment

  17. Microsoft Virtualization Master Microsoft Server, Desktop, Application, and Presentation Virtualization

    CERN Document Server

    Olzak, Thomas; Boomer, Jason; Keefer, Robert M

    2010-01-01

    Microsoft Virtualization helps you understand and implement the latest virtualization strategies available with Microsoft products. This book focuses on: Server Virtualization, Desktop Virtualization, Application Virtualization, and Presentation Virtualization. Whether you are managing Hyper-V, implementing desktop virtualization, or even migrating virtual machines, this book is packed with coverage on all aspects of these processes. Written by a talented team of Microsoft MVPs, Microsoft Virtualization is the leading resource for a full installation, migration, or integration of virtual syste

  18. Art/Net/Work

    DEFF Research Database (Denmark)

    Andersen, Christian Ulrik; Lindstrøm, Hanne

    2006-01-01

    The seminar Art|Net|Work deals with two important changes in our culture. On one side, the network has become essential in the latest technological development. The Internet has entered a new phase, Web 2.0, including the occurrence of as ‘Wiki’s’, ‘Peer-2-Peer’ distribution, user controlled...... on the ‘network’ itself as a phenomenon and are often using technological networks as a mean of production and distribution. This changes the artistic practice and the distribution channels of art works – and the traditional notions of ‘work’, ‘origin’ and ‘rights’ are increasingly perceived as limiting...... the praxis of the artist. We see different kinds of interventions and activism (including ‘hacktivism’) using the network as a way of questioning the invisible rules that govern public and semi-public spaces. Who ‘owns’ them? What kind of social relationships do they generate? On what principle...

  19. Net4Care

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Hansen, Klaus Marius

    2012-01-01

    , health centers are getting larger and more distributed, and the number of healthcare professionals does not follow the trend in chronic diseases. All of this leads to a need for telemedical and mobile health applications. In a Danish context, these applications are often developed through local...... (innovative) initiatives with little regards for national and global (standardization) initiatives. A reason for this discrepancy is that the software architecture for national (and global) systems and standards are hard to understand, hard to develop systems based on, and hard to deploy. To counter this, we...... propose a software ecosystem approach for telemedicine applications, providing a framework, Net4Care, encapsulating national/global design decisions with respect to standardization while allowing for local innovation. This paper presents an analysis of existing systems, of requirements for a software...

  20. Liquid metal cooled blanket concept for NET

    International Nuclear Information System (INIS)

    Malang, S.; Casal, V.; Arheidt, K.; Fischer, U.; Link, W.; Rust, K.

    1986-01-01

    A blanket concept for NET using liquid lithium-lead both as breeder material and as coolant is described. The need for inboard breeding is avoided by using beryllium as neutron multiplier in the outboard blanket. Novel flow channel inserts are employed in all poloidal ducts to reduce the MHD pressure drop. The concept offers a simple mechanical design and a higher tritium breeding ratio compared to water- and gas-cooled blankets. (author)

  1. High-level Petri Nets

    DEFF Research Database (Denmark)

    various journals and collections. As a result, much of this knowledge is not readily available to people who may be interested in using high-level nets. Within the Petri net community this problem has been discussed many times, and as an outcome this book has been compiled. The book contains reprints...... of some of the most important papers on the application and theory of high-level Petri nets. In this way it makes the relevant literature more available. It is our hope that the book will be a useful source of information and that, e.g., it can be used in the organization of Petri net courses. To make......High-level Petri nets are now widely used in both theoretical analysis and practical modelling of concurrent systems. The main reason for the success of this class of net models is that they make it possible to obtain much more succinct and manageable descriptions than can be obtained by means...

  2. Net energy from nuclear power

    International Nuclear Information System (INIS)

    Rotty, R.M.; Perry, A.M.; Reister, D.B.

    1975-11-01

    An analysis of net energy from nuclear power plants is dependent on a large number of variables and assumptions. The energy requirements as they relate to reactor type, concentration of uranium in the ore, enrichment tails assays, and possible recycle of uranium and plutonium were examined. Specifically, four reactor types were considered: pressurized water reactor, boiling water reactor, high temperature gas-cooled reactor, and heavy water reactor (CANDU). The energy requirements of systems employing both conventional (current) ores with uranium concentration of 0.176 percent and Chattanooga Shales with uranium concentration of 0.006 percent were determined. Data were given for no recycle, uranium recycle only, and uranium plus plutonium recycle. Starting with the energy requirements in the mining process and continuing through fuel reprocessing and waste storage, an evaluation of both electrical energy requirements and thermal energy requirements of each process was made. All of the energy, direct and indirect, required by the processing of uranium in order to produce electrical power was obtained by adding the quantities for the individual processes. The energy inputs required for the operation of a nuclear power system for an assumed life of approximately 30 years are tabulated for nine example cases. The input requirements were based on the production of 197,100,000 MWH(e), i.e., the operation of a 1000 MW(e) plant for 30 years with an average plant factor of 0.75. Both electrical requirements and thermal energy requirements are tabulated, and it should be emphasized that both quantities are needed. It was found that the electricity generated far exceeded the energy input requirements for all the cases considered

  3. Net neutrality and audiovisual services

    OpenAIRE

    van Eijk, N.; Nikoltchev, S.

    2011-01-01

    Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication networks: the control over the distribution of audiovisual services constitutes a vital part of the problem. In this contribution, the phenomenon of net neutrality is described first. Next, the European a...

  4. NetView technical research

    Science.gov (United States)

    1993-01-01

    This is the Final Technical Report for the NetView Technical Research task. This report is prepared in accordance with Contract Data Requirements List (CDRL) item A002. NetView assistance was provided and details are presented under the following headings: NetView Management Systems (NMS) project tasks; WBAFB IBM 3090; WPAFB AMDAHL; WPAFB IBM 3084; Hill AFB; McClellan AFB AMDAHL; McClellan AFB IBM 3090; and Warner-Robins AFB.

  5. Application of bias factor method with use of virtual experimental value to prediction uncertainty reduction in void reactivity worth of breeding light water reactor

    International Nuclear Information System (INIS)

    Kugo, Teruhiko; Mori, Takamasa; Kojima, Kensuke; Takeda, Toshikazu

    2007-01-01

    We have carried out the critical experiments for the MOX fueled tight lattice LWR cores using FCA facility and constructed the XXII-1 series cores. Utilizing the critical experiments carried out at FCA, we have evaluated the reduction of prediction uncertainty in the coolant void reactivity worth of the breeding LWR core based on the bias factor method with focusing on the prediction uncertainty due to cross section errors. In the present study, we have introduced a concept of a virtual experimental value into the conventional bias factor method to overcome a problem caused by the conventional bias factor method in which the prediction uncertainty increases in the case that the experimental core has the opposite reactivity worth and the consequent opposite sensitivity coefficients to the real core. To extend the applicability of the bias factor method, we have adopted an exponentiated experimental value as the virtual experimental value and formulated the prediction uncertainty reduction by the use of the bias factor method extended by the concept of the virtual experimental value. From the numerical evaluation, it has been shown that the prediction uncertainty due to cross section errors has been reduced by the use of the concept of the virtual experimental value. It is concluded that the introduction of virtual experimental value can effectively utilize experimental data and extend applicability of the bias factor method. (author)

  6. Initial CAD investigations for NET

    International Nuclear Information System (INIS)

    Katz, F.; Leinemann, K.; Ludwig, A.; Marek, U.; Olbrich, W.; Schlechtendahl, E.G.

    1985-11-01

    This report summarizes the work done under contract no. 164/84-7/FU-D-/NET between the Commission of the European Communities and KfK during the period from June 1, 1984, through May 31, 1985. The following topics are covered in this report: Initial modelling of NET version NET2A, CAD system extension for remote handling studies, analysis of the CAD information structure, work related to the transfer of CAD information between KfK and the NET team. (orig.) [de

  7. Understanding Net Zero Energy Buildings

    DEFF Research Database (Denmark)

    Salom, Jaume; Widén, Joakim; Candanedo, José

    2011-01-01

    Although several alternative definitions exist, a Net-Zero Energy Building (Net ZEB) can be succinctly described as a grid-connected building that generates as much energy as it uses over a year. The “net-zero” balance is attained by applying energy conservation and efficiency measures...... and by incorporating renewable energy systems. While based on annual balances, a complete description of a Net ZEB requires examining the system at smaller time-scales. This assessment should address: (a) the relationship between power generation and building loads and (b) the resulting interaction with the power grid...

  8. A Science Cloud: OneSpaceNet

    Science.gov (United States)

    Morikawa, Y.; Murata, K. T.; Watari, S.; Kato, H.; Yamamoto, K.; Inoue, S.; Tsubouchi, K.; Fukazawa, K.; Kimura, E.; Tatebe, O.; Shimojo, S.

    2010-12-01

    Main methodologies of Solar-Terrestrial Physics (STP) so far are theoretical, experimental and observational, and computer simulation approaches. Recently "informatics" is expected as a new (fourth) approach to the STP studies. Informatics is a methodology to analyze large-scale data (observation data and computer simulation data) to obtain new findings using a variety of data processing techniques. At NICT (National Institute of Information and Communications Technology, Japan) we are now developing a new research environment named "OneSpaceNet". The OneSpaceNet is a cloud-computing environment specialized for science works, which connects many researchers with high-speed network (JGN: Japan Gigabit Network). The JGN is a wide-area back-born network operated by NICT; it provides 10G network and many access points (AP) over Japan. The OneSpaceNet also provides with rich computer resources for research studies, such as super-computers, large-scale data storage area, licensed applications, visualization devices (like tiled display wall: TDW), database/DBMS, cluster computers (4-8 nodes) for data processing and communication devices. What is amazing in use of the science cloud is that a user simply prepares a terminal (low-cost PC). Once connecting the PC to JGN2plus, the user can make full use of the rich resources of the science cloud. Using communication devices, such as video-conference system, streaming and reflector servers, and media-players, the users on the OneSpaceNet can make research communications as if they belong to a same (one) laboratory: they are members of a virtual laboratory. The specification of the computer resources on the OneSpaceNet is as follows: The size of data storage we have developed so far is almost 1PB. The number of the data files managed on the cloud storage is getting larger and now more than 40,000,000. What is notable is that the disks forming the large-scale storage are distributed to 5 data centers over Japan (but the storage

  9. A Virtual Class Calculus

    DEFF Research Database (Denmark)

    Ernst, Erik; Ostermann, Klaus; Cook, William Randall

    2006-01-01

    Virtual classes are class-valued attributes of objects. Like virtual methods, virtual classes are defined in an object's class and may be redefined within subclasses. They resemble inner classes, which are also defined within a class, but virtual classes are accessed through object instances...... model for virtual classes has been a long-standing open question. This paper presents a virtual class calculus, vc, that captures the essence of virtual classes in these full-fledged programming languages. The key contributions of the paper are a formalization of the dynamic and static semantics of vc...

  10. Virtual Trackballs Revisited

    DEFF Research Database (Denmark)

    Henriksen, Knud; Sporring, Jon; Hornbæk, Kasper

    2004-01-01

    reviews and provides a mathematical foundation for virtual trackballs. The first, but still popular, virtual trackball was described by Chen et al. [CHECK END OF SENTENCE]. We show that the virtual trackball by Chen et al. does not rotate the object along the intended great circular arc on the virtual...... trackball and we give a correction. Another popular virtual trackball is Shoemake's quaternion implementation [CHECK END OF SENTENCE], which we show to be a special case of the virtual trackball by Chen et al.. Shoemake extends the scope of the virtual trackball to the full screen. Unfortunately, Shoemake......'s virtual trackball is inhomogeneous and discontinuous with consequences for usability. Finally, we review Bell's virtual trackball [CHECK END OF SENTENCE] and discuss studies of the usability of virtual trackballs....

  11. Virtual cystoscopy.

    Science.gov (United States)

    Mohammed, Aza; Simpson, Adam; Zamora, Ignacio; Gilliland, Leslie

    2008-07-01

    Bladder cancer is a common problem facing urologists worldwide. The gold standard for its diagnosis and follow-up is the direct visualization of the tumor using conventional cystoscopy. Despite having high sensitivity and specificity for detecting bladder cancer, conventional cystoscopy is regarded as an invasive procedure which is associated with several complications. In addition, regular follow-up of patients with bladder cancer is a financial burden on the health system. With the progressive development in diagnostic imaging and medical computer software technologies, it was possible to generate virtual reality images to aid the clinician to inspect the interior of the bladder in real time. This technology is considered as a safe test for bladder cancer diagnosis and follow-up, and it is associated with cancer detection rates comparable with conventional cystoscopy. However, it is associated with some drawbacks that limit its use in routine clinical practice at the current time. In this paper, we review the development and clinical applications of this technology.

  12. Design and Test of the Cross-Format Schema Protocol (XFSP) for Networked Virtual Environments

    National Research Council Canada - National Science Library

    Serin, Ekrem

    2003-01-01

    A Networked Virtual Environment (Net-VE) is a distributed software system in which multiple users interact with each other in real time even though these users may be located around the world Zyda 99...

  13. Rare, but challenging tumors: NET

    International Nuclear Information System (INIS)

    Ivanova, D.; Balev, B.

    2013-01-01

    Full text: Introduction: Gastroenteropancreatic Neuroendocrine Tumors (GEP - NET) are a heterogeneous group of tumors with different locations and many different clinical, histological, and imaging performance. In a part of them a secretion of various organic substances is present. The morbidity of GEP - NET in the EU is growing, and this leads to increase the attention to them. What you will learn: Imaging methods used for localization and staging of GEP - NET, characteristics of the study’s protocols; Classification of GEP - NET; Demonstration of typical and atypical imaging features of GEP - NET in patients registered at the NET Center at University Hospital ‘St. Marina’, Varna; Features of metastatic NET, The role of imaging in the evaluation of treatment response and follow-up of the patients. Discussion: The image semiotics analysis is based on 19 cases of GEP - NET registered NET Center at University Hospital ‘St. Marina’. The main imaging method is multidetector CT (MDCT), and magnetic resonance imaging (MRI ) has advantages in the evaluation of liver lesions and the local prevalence of anorectal tumors. In patients with advanced disease and liver lesions the assessment of skeletal involvement (MRI/ nuclear medical method) is mandatory. The majority of GEP - NET have not any specific imaging findings. Therefore it is extremely important proper planning and conducting of the study (MDCT and MR enterography; accurate assessment phase of scanning, positive and negative contrast). Conclusion: GEP - NET is a major diagnostic challenge due to the absence of typical imaging characteristics and often an overlap with those of the tumors of different origin can be observed. Therefore, a good knowledge of clinical and imaging changes occurring at different locations is needed. MDCT is the basis for the diagnosis, staging and follow-up of these neoplasms

  14. Virtual Web Services

    OpenAIRE

    Rykowski, Jarogniew

    2007-01-01

    In this paper we propose an application of software agents to provide Virtual Web Services. A Virtual Web Service is a linked collection of several real and/or virtual Web Services, and public and private agents, accessed by the user in the same way as a single real Web Service. A Virtual Web Service allows unrestricted comparison, information merging, pipelining, etc., of data coming from different sources and in different forms. Detailed architecture and functionality of a single Virtual We...

  15. Virtual button interface

    Science.gov (United States)

    Jones, J.S.

    1999-01-12

    An apparatus and method of issuing commands to a computer by a user interfacing with a virtual reality environment are disclosed. To issue a command, the user directs gaze at a virtual button within the virtual reality environment, causing a perceptible change in the virtual button, which then sends a command corresponding to the virtual button to the computer, optionally after a confirming action is performed by the user, such as depressing a thumb switch. 4 figs.

  16. Virtual reality in education

    OpenAIRE

    Minocha, Shailey; Tudor, Ana-Despina

    2017-01-01

    In this workshop-presentation, we described the evolution of virtual reality technologies and our research from 3D virtual worlds, 3D virtual environments built in gaming environments such as Unity 3D, 360-degree videos, and mobile virtual reality via Google Expeditions. For each of these four technologies, we discussed the affordances of the technologies and how they contribute towards learning and teaching. We outlined the significance of students being aware of the different virtual realit...

  17. Virtual reality - aesthetic consequences

    OpenAIRE

    Benda, Lubor

    2014-01-01

    In the present work we study aesthetic consequences of virtual reality. Exploring the fringe between fictional and virtual is one of the key goals, that will be achieved through etymologic and technologic definition of both fiction and virtual reality, fictional and virtual worlds. Both fiction and virtual reality will be then studied from aesthetic distance and aesthetic pleasure point of view. At the end, we will see the main difference as well as an common grounds between fiction and virtu...

  18. Virtual goods recommendations in virtual worlds.

    Science.gov (United States)

    Chen, Kuan-Yu; Liao, Hsiu-Yu; Chen, Jyun-Hung; Liu, Duen-Ren

    2015-01-01

    Virtual worlds (VWs) are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies' intelligence resources, but also makes it difficult for users to find suitable virtual goods fit for their virtual home in daily virtual life. In the VWs, users decorate their houses, visit others' homes, create families, host parties, and so forth. Users establish their social life circles through these activities. This research proposes a novel virtual goods recommendation method based on these social interactions. The contact strength and contact influence result from interactions with social neighbors and influence users' buying intention. Our research highlights the importance of social interactions in virtual goods recommendation. The experiment's data were retrieved from an online VW platform, and the results show that the proposed method, considering social interactions and social life circle, has better performance than existing recommendation methods.

  19. LeatherNet: an evaluation as a mission planning and briefing tool

    OpenAIRE

    Hague, Tracy R.

    1996-01-01

    Information Technology Management The author evaluates LeatherNet, a Distributed Interactive Simulation compliant, virtual simulation system being developed by the Advanced Research Projects Agency to demonstrate Modeling and Simulation(M&S) technologies and to partially fulfill the U. S. Marine Corps M&S goals. The research focuses on evaluation of LeatherNet as a mission planning and briefing tool for Marine infantry company commanders, staff, and subordinate leaders. Evaluation is based...

  20. Linear Logic on Petri Nets

    DEFF Research Database (Denmark)

    Engberg, Uffe Henrik; Winskel, Glynn

    This article shows how individual Petri nets form models of Girard's intuitionistic linear logic. It explores questions of expressiveness and completeness of linear logic with respect to this interpretation. An aim is to use Petri nets to give an understanding of linear logic and give some apprai...

  1. Net neutrality and audiovisual services

    NARCIS (Netherlands)

    van Eijk, N.; Nikoltchev, S.

    2011-01-01

    Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication

  2. Properties of porous netted materials

    International Nuclear Information System (INIS)

    Daragan, V.D.; Drozdov, B.G.; Kotov, A.Yu.; Mel'nikov, G.N.; Pustogarov, A.V.

    1987-01-01

    Hydraulic and strength characteristics, efficient heat conduction and inner heat exchange coefficient are experimentally studied for porous netted materials on the base of the brass nets as dependent on porosity, cell size and method of net laying. Results of the studies are presented. It is shown that due to anisotropy of the material properties the hydraulic resistance in the direction parallel to the nets plane is 1.3-1.6 times higher than in the perpendicular one. Values of the effective heat conduction in the direction perpendicular to the nets plane at Π>0.45 agree with the data from literature, at Π<0.45 a deviation from the calculated values is marked in the direction of the heat conduction decrease

  3. NET remote workstation

    International Nuclear Information System (INIS)

    Leinemann, K.

    1990-10-01

    The goal of this NET study was to define the functionality of a remote handling workstation and its hardware and software architecture. The remote handling workstation has to fulfill two basic functions: (1) to provide the man-machine interface (MMI), that means the interface to the control system of the maintenance equipment and to the working environment (telepresence) and (2) to provide high level (task level) supporting functions (software tools) during the maintenance work and in the preparation phase. Concerning the man-machine interface, an important module of the remote handling workstation besides the standard components of man-machine interfacing is a module for graphical scene presentation supplementing viewing by TV. The technique of integrated viewing is well known from JET BOOM and TARM control using the GBsim and KISMET software. For integration of equipment dependent MMI functions the remote handling workstation provides a special software module interface. Task level support of the operator is based on (1) spatial (geometric/kinematic) models, (2) remote handling procedure models, and (3) functional models of the equipment. These models and the related simulation modules are used for planning, programming, execution monitoring, and training. The workstation provides an intelligent handbook guiding the operator through planned procedures illustrated by animated graphical sequences. For unplanned situations decision aids are available. A central point of the architectural design was to guarantee a high flexibility with respect to hardware and software. Therefore the remote handling workstation is designed as an open system based on widely accepted standards allowing the stepwise integration of the various modules starting with the basic MMI and the spatial simulation as standard components. (orig./HP) [de

  4. RadNet Radiological Air Monitoring Network

    International Nuclear Information System (INIS)

    Scott Telofski, J.; Askren, D.R.; Petko, Ch.M.; Fraass, R.G.

    2010-01-01

    The United States Environmental Protection Agency operates a national environmental radiation monitoring program called RadNet. RadNet monitors airborne particulates, precipitation, milk, and drinking water for radiation levels. The primary purpose of the original program in the 1950's and 1960's was to collect and analyze samples in various media to assess the effects of radioactive fallout from above-ground nuclear weapon testing. As above-ground testing diminished in the 1970's, the program, especially the air network, became critical in evaluating effects of other types of nuclear incidents, such as the nuclear reactor accident at Chernobyl, as well as monitoring trends in environmental radioactive contamination. The value of rapid data collection subsequent to such incidents led to the consideration of developing air monitors with radiation detectors and telecommunication equipment for real-time radiation measurement. The strengthened United States homeland security posture after 2001 led to production and installation of the current real-time RadNet air monitors. There are now 118 stationary, continuously operating air monitoring stations and 40 mobile air monitors for site specific monitoring. The stationary air monitors include radiation detectors, meteorological sensors, a high-volume air sampler, and communication devices for hourly data transfers. When unusual levels are detected, scientists download a full sodium iodide detector spectrum for analysis. The real-time data collected by RadNet stationary systems permit rapid identification and quantification of airborne nuclides with sufficient sensitivity to provide critical information to help determine protective actions. The data also may help to rapidly refine long-range radioactive plume models and estimate exposure to the population. This paper provides an overview of the airborne particulate monitoring conducted during above-ground nuclear weapon testing, summarizes the uses of data from the program

  5. Discards of Danish set nets fisheries in the Kattegat

    DEFF Research Database (Denmark)

    Savina, Esther; Krag, Ludvig Ahm; Frandsen, Rikke

    to the food web. These ecological interactions can be of importance for the surrounding ecosystem, especially regarding small-scale fisheries which take place in relatively shallow waters. Previous studies on gill- or trammel nets discards mostly focus either on commercially valuable fish, or on incidentally...... caught rare or protected species. Data collected by observers aboard commercial fishing vessels gives a first insight into the discards of non-commercial fish and invertebrates in the Danish small-scale set nets fisheries...

  6. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-08-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  7. Pro asynchronous programming with .NET

    CERN Document Server

    Blewett, Richard; Ltd, Rock Solid Knowledge

    2014-01-01

    Pro Asynchronous Programming with .NET teaches the essential skill of asynchronous programming in .NET. It answers critical questions in .NET application development, such as: how do I keep my program responding at all times to keep my users happy how do I make the most of the available hardware how can I improve performanceIn the modern world, users expect more and more from their applications and devices, and multi-core hardware has the potential to provide it. But it takes carefully crafted code to turn that potential into responsive, scalable applications.With Pro Asynchronous Programming

  8. Microbial activity in district cooling nets; Mikrobiell Aktivitet i Fjaerrkylenaet

    Energy Technology Data Exchange (ETDEWEB)

    Nordling, Magnus [Swedish Corrosion Inst., Stockholm (Sweden)

    2004-07-01

    Four district cooling nets with varying water quality have been investigated according to presence of microbially related problems. The aim has been to formulate recommendations regarding the water quality and regarding other procedures that might reduce the risk for biofilm formation and microbial corrosion. The method has consisted of using so called exposure containers, connected to each net. The water has been allowed to flow through the exposure containers where coupons of carbon steel have been exposed. The coupons have been withdrawn at different times, and analysed regarding the presence of biofilm and corrosion attack. Analyses have also been made regarding the amount of a number of different types of micro-organisms in the biofilm and in the district cooling water. The project has been divided in two phases. During the first phase of the project only two nets were investigated, one with municipal water and one with water of district heating quality, i.e. degassed and deionised. Biofilms could be seen on the coupons from both nets, even though the exposure time only had been 1.5 month. Considerable concentrations of micro-organisms were found in the biofilms and in the water for both nets, however much larger amounts for the net with municipal water. During the second phase of the project four nets were investigated, two with mainly municipal water and two with water of district heating quality. Here, on the other hand, it could be seen that the two nets with municipal water had micro-organisms of equivalent or lower concentrations compared to the two nets with water of district heating quality. One explanation to this is that the colouring substance pyranine is added to these two nets. Pyranine is added for the purpose of easily detecting a leakage but is at the same time a carbon compound, and as such a possible nutrient for the micro-organisms. This illustrates the importance of having the district cooling water as free from additives as possible. Other

  9. Pickering nuclear fish diversion net

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, J.; Lew, A. [Ontario Power Generation, Toronto, Ontario (Canada)

    2013-07-01

    Pickering Fish Diversion Net - An Engineered Environmental Solution that has significantly reduced fish impingement at the Pickering Nuclear Facility. Note: As a recent urgent request/discussed by Mark Elliot, CNE-OPG and Jacques Plourde, CNS.

  10. PolicyNet Publication System

    Data.gov (United States)

    Social Security Administration — The PolicyNet Publication System project will merge the Oracle-based Policy Repository (POMS) and the SQL-Server CAMP system (MSOM) into a new system with an Oracle...

  11. Net Neutrality: Background and Issues

    National Research Council Canada - National Science Library

    Gilroy, Angele A

    2006-01-01

    .... The move to place restrictions on the owners of the networks that compose and provide access to the Internet, to ensure equal access and nondiscriminatory treatment, is referred to as "net neutrality...

  12. Analisis Determinan Net Ekspor Indonesia

    OpenAIRE

    Daulay, Rahmawaty

    2010-01-01

    This study is to analyzing empirically among Indonesia GDP, trade partnership GDP (Malaysia, Singapore, US and Thailand) and real exchange rate toward Indonesia Net Export. To find out which one from those three variables is significant in order to fluctuating (increasing or decreasing) Indonesia Net Export either in the short run or in the long run. Data collection is obtained using secondary data, namely Indonesia GDP, Malaysia GDP, Singapura GDP, US GDP, Thailand GDP and real exchange rate...

  13. NetBeans GUI Builder

    OpenAIRE

    Pusiankova, Tatsiana

    2009-01-01

    This work aims at making readers familiar with the powerful tool NetBeans IDE GUI Builder and helping them make their first steps to creation of their own graphical user interface in the Java programming language. The work includes theoretical description of NetBeans IDE GUI Builder, its most important characteristics and peculiarities and also a set of practical instructions that will help readers in creation of their first GUI. The readers will be introduced to the environment of this tool ...

  14. Virtual Trackballs Revisited

    OpenAIRE

    Henriksen, Knud; Sporring, Jon; Hornbæk, Kasper

    2004-01-01

    Udgivelsesdato: March/April Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-aided design, operation simulations, and desktop virtual reality. The most commonly used rotation technique is a virtual trackball surrounding the object and operated by the mouse pointer. This article reviews and provides a mathematical foundation for virtual trackballs. The first, but still popular, virtual trackball was described by Chen et al. [CHECK END OF SENTENC...

  15. Server virtualization solutions

    OpenAIRE

    Jonasts, Gusts

    2012-01-01

    Currently in the information technology sector that is responsible for a server infrastructure is a huge development in the field of server virtualization on x86 computer architecture. As a prerequisite for such a virtualization development is growth in server productivity and underutilization of available computing power. Several companies in the market are working on two virtualization architectures – hypervizor and hosting. In this paper several of virtualization products that use host...

  16. Virtual currencies- Real opportunities?

    OpenAIRE

    Selldahl, Sara

    2013-01-01

    The European Central Bank defines virtual currencies as ”unregulated, digital money, which is issued and usually controlled by its developers, and used and accepted among the members of a specific virtual community.” (European Central Bank, 2012, p. 5) The interest in virtual currencies has increased immensely over the last few years as they become increasingly prevalent in our society across many different industries. Up until now, the field of virtual currencies has been mainly uncharted ...

  17. Virtual reality exposure therapy

    OpenAIRE

    Rothbaum, BO; Hodges, L; Kooper, R

    1997-01-01

    It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer- generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first control...

  18. Interactive Virtual Cinematography

    OpenAIRE

    Burelli, Paolo

    2012-01-01

    A virtual camera represents the point-of-view of the player through which sheperceives the game world and gets feedback on her actions. Thus, the virtualcamera plays a vital role in 3D computer games and aects player experienceand enjoyability in games. Interactive virtual cinematography is the process ofvisualising the content of a virtual environment by positioning and animatingthe virtual camera in the context of interactive applications such as a computergame.Camera placement and animatio...

  19. Multiflavor string-net models

    Science.gov (United States)

    Lin, Chien-Hung

    2017-05-01

    We generalize the string-net construction to multiple flavors of strings, each of which is labeled by the elements of an Abelian group Gi. The same flavor of strings can branch, while different flavors of strings can cross one another and thus they form intersecting string nets. We systematically construct the exactly soluble lattice Hamiltonians and the ground-state wave functions for the intersecting string-net condensed phases. We analyze the braiding statistics of the low-energy quasiparticle excitations and find that our model can realize all the topological phases as the string-net model with group G =∏iGi . In this respect, our construction provides various ways of building lattice models which realize topological order G , corresponding to different partitions of G and thus different flavors of string nets. In fact, our construction concretely demonstrates the Künneth formula by constructing various lattice models with the same topological order. As an example, we construct the G =Z2×Z2×Z2 string-net model which realizes a non-Abelian topological phase by properly intersecting three copies of toric codes.

  20. Virtual Reality: An Overview.

    Science.gov (United States)

    Franchi, Jorge

    1994-01-01

    Highlights of this overview of virtual reality include optics; interface devices; virtual worlds; potential applications, including medicine and archaeology; problems, including costs; current research and development; future possibilities; and a listing of vendors and suppliers of virtual reality products. (Contains 11 references.) (LRW)

  1. The Virtuality Continuum Revisited

    NARCIS (Netherlands)

    Nijholt, Antinus; Traum, D.; Zhai, Sh.; Kellogg, W.

    2005-01-01

    We survey the themes and the aims of a workshop devoted to the state-of-the-art virtuality continuum. In this continuum, ranging from fully virtual to real physical environments, allowing for mixed, augmented and desktop virtual reality, several perspectives can be taken. Originally, the emphasis

  2. Virtual Reference Services.

    Science.gov (United States)

    Brewer, Sally

    2003-01-01

    As the need to access information increases, school librarians must create virtual libraries. Linked to reliable reference resources, the virtual library extends the physical collection and library hours and lets students learn to use Web-based resources in a protected learning environment. The growing number of virtual schools increases the need…

  3. New Desktop Virtual Reality Technology in Technical Education

    Science.gov (United States)

    Ausburn, Lynna J.; Ausburn, Floyd B.

    2008-01-01

    Virtual reality (VR) that immerses users in a 3D environment through use of headwear, body suits, and data gloves has demonstrated effectiveness in technical and professional education. Immersive VR is highly engaging and appealing to technically skilled young Net Generation learners. However, technical difficulty and very high costs have kept…

  4. WE-NET: Japanese hydrogen program

    International Nuclear Information System (INIS)

    Mitsugi, Chiba; Harumi, Arai; Kenzo, Fukuda

    1998-01-01

    The Agency of Industrial Science and Technology (AIST), in the Ministry of International Trade and Industry (MITI), started the New Sunshine Program in 1993 by unifying the Sunshine Program (R and D on new energy technology), the Moonlight Program (R and D on energy conservation technology), and the Research and Development Program for Environmental Technology. The objective of the new program is to develop innovative technologies to allow sustainable growth while solving energy and environmental issues. One of the new projects in this program is the ''International Clean Energy System Technology Utilizing Hydrogen (World Energy Network)'': WE-NET. The goal of WE-NET is to construct a worldwide energy network for effective supply, transportation and utilization of renewable energy using hydrogen. The WE-NET program extends over 28 years from 1993 to 2020. In Phase 1, we started core research in areas such as development of high efficiency technologies including hydrogen production using polymer electrolyte membrane water electrolysis, hydrogen combustion turbines, etc. (author)

  5. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  6. Hybrid Analysis of Blue Water Consumption and Water Scarcity Implications at the Global, National, and Basin Levels in an Increasingly Globalized World.

    Science.gov (United States)

    Wang, Ranran; Zimmerman, Julie

    2016-05-17

    As the fifth global water footprint assessment, this study enhanced previous estimates of national blue water consumption (including fresh surface and groundwater) and main economic activities with (1) improved spatial and sectoral resolution and (2) quantified the impacts of virtual water trade on water use and water stress at both the national and basin level. In 2007, 1194 Gm(3) of blue water was consumed globally for human purposes. The consuming (producing) of primary and manufactured goods and services from the sectors of "Primary Crops and Livestock", "Primary Energy and Minerals", "Processed Food and Beverages", "Non-food Manufactured Products", "Electricity", "Commercial and Public Services", and "Households" accounted for 33% (91%), ∼ 0% (1%), 37% (water consumption, respectively. The considerable differences in sectoral water consumption accounted for by the two perspectives (consumption- vs production-based) highlight the significance of the water consumed indirectly, upstream in the supply chain (i.e., > 70% of total blue water consumption) while offering additional insights into the water implications of critical interconnected economic activities, such as the water-energy nexus. With 145 Gm(3) (12%) of the blue water consumption embedded in the goods and services traded internationally, 89 countries analyzed were net blue water importers at the national level. On the basin level, the impacts of virtual water trade on water stress were statistically significant for basins across the world and within 104 countries; virtual water trade mitigated water stress for the basins within 85 of the 104 countries, including all of those where there are moderate and greater water stress countrywide (except Italy).

  7. Controls on the variability of net infiltration to desert sandstone

    Science.gov (United States)

    Heilweil, Victor M.; McKinney, Tim S.; Zhdanov, Michael S.; Watt, Dennis E.

    2007-01-01

    As populations grow in arid climates and desert bedrock aquifers are increasingly targeted for future development, understanding and quantifying the spatial variability of net infiltration becomes critically important for accurately inventorying water resources and mapping contamination vulnerability. This paper presents a conceptual model of net infiltration to desert sandstone and then develops an empirical equation for its spatial quantification at the watershed scale using linear least squares inversion methods for evaluating controlling parameters (independent variables) based on estimated net infiltration rates (dependent variables). Net infiltration rates used for this regression analysis were calculated from environmental tracers in boreholes and more than 3000 linear meters of vadose zone excavations in an upland basin in southwestern Utah underlain by Navajo sandstone. Soil coarseness, distance to upgradient outcrop, and topographic slope were shown to be the primary physical parameters controlling the spatial variability of net infiltration. Although the method should be transferable to other desert sandstone settings for determining the relative spatial distribution of net infiltration, further study is needed to evaluate the effects of other potential parameters such as slope aspect, outcrop parameters, and climate on absolute net infiltration rates.

  8. Virtualization A Manager's Guide

    CERN Document Server

    Kusnetzky, Dan

    2011-01-01

    What exactly is virtualization? As this concise book explains, virtualization is a smorgasbord of technologies that offer organizations many advantages, whether you're managing extremely large stores of rapidly changing data, scaling out an application, or harnessing huge amounts of computational power. With this guide, you get an overview of the five main types of virtualization technology, along with information on security, management, and modern use cases. Topics include: Access virtualization-Allows access to any application from any deviceApplication virtualization-Enables applications

  9. Perception of Virtual Audiences.

    Science.gov (United States)

    Chollet, Mathieu; Scherer, Stefan

    2017-01-01

    A growing body of evidence shows that virtual audiences are a valuable tool in the treatment of social anxiety, and recent works show that it also a useful in public-speaking training programs. However, little research has focused on how such audiences are perceived and on how the behavior of virtual audiences can be manipulated to create various types of stimuli. The authors used a crowdsourcing methodology to create a virtual audience nonverbal behavior model and, with it, created a dataset of videos with virtual audiences containing varying behaviors. Using this dataset, they investigated how virtual audiences are perceived and which factors affect this perception.

  10. CellNet: Network Biology Applied to Stem Cell Engineering

    Science.gov (United States)

    Cahan, Patrick; Li, Hu; Morris, Samantha A.; da Rocha, Edroaldo Lummertz; Daley, George Q.; Collins, James J.

    2014-01-01

    SUMMARY Somatic cell reprogramming, directed differentiation of pluripotent stem cells, and direct conversions between differentiated cell lineages represent powerful approaches to engineer cells for research and regenerative medicine. We have developed CellNet, a network biology platform that more accurately assesses the fidelity of cellular engineering than existing methodologies and generates hypotheses for improving cell derivations. Analyzing expression data from 56 published reports, we found that cells derived via directed differentiation more closely resemble their in vivo counterparts than products of direct conversion, as reflected by the establishment of target cell-type gene regulatory networks (GRNs). Furthermore, we discovered that directly converted cells fail to adequately silence expression programs of the starting population, and that the establishment of unintended GRNs is common to virtually every cellular engineering paradigm. CellNet provides a platform for quantifying how closely engineered cell populations resemble their target cell type and a rational strategy to guide enhanced cellular engineering. PMID:25126793

  11. Comparison of the performance of net radiation calculation models

    DEFF Research Database (Denmark)

    Kjærsgaard, Jeppe Hvelplund; Cuenca, R.H.; Martinez-Cob, A.

    2009-01-01

    . The long-wave radiation models included a physically based model, an empirical model from the literature, and a new empirical model. Both empirical models used only solar radiation as required for meteorological input. The long-wave radiation models were used with model calibration coefficients from......Daily values of net radiation are used in many applications of crop-growth modeling and agricultural water management. Measurements of net radiation are not part of the routine measurement program at many weather stations and are commonly estimated based on other meteorological parameters. Daily...... values of net radiation were calculated using three net outgoing long-wave radiation models and compared to measured values. Four meteorological datasets representing two climate regimes, a sub-humid, high-latitude environment and a semi-arid mid-latitude environment, were used to test the models...

  12. A virtual tour of virtual reality

    Science.gov (United States)

    Harris, Margaret

    2018-03-01

    Virtual-reality glasses might still be on the starting blocks, but plenty of companies are working on the technology. Margaret Harris tries on some examples at the Photonics West show in San Francisco

  13. MATT: Multi Agents Testing Tool Based Nets within Nets

    Directory of Open Access Journals (Sweden)

    Sara Kerraoui

    2016-12-01

    As part of this effort, we propose a model based testing approach for multi agent systems based on such a model called Reference net, where a tool, which aims to providing a uniform and automated approach is developed. The feasibility and the advantage of the proposed approach are shown through a short case study.

  14. Net4Care PHMR Library

    DEFF Research Database (Denmark)

    2014-01-01

    The Net4Care PHMR library contains a) A GreenCDA approach for constructing a data object representing a PHMR document: SimpleClinicalDocument, and b) A Builder which can produce a XML document representing a valid Danish PHMR (following the MedCom profile) document from the SimpleClinicalDocument......The Net4Care PHMR library contains a) A GreenCDA approach for constructing a data object representing a PHMR document: SimpleClinicalDocument, and b) A Builder which can produce a XML document representing a valid Danish PHMR (following the MedCom profile) document from the Simple...

  15. [Zr(NEtMe)2(guan-NEtMe)2] as a novel ALD precursor: ZrO2 film growth and mechanistic studies

    NARCIS (Netherlands)

    Blanquart, T.; Niinistö, J.; Aslam, N.; Banerjee, M.; Tomczak, Y.; Gavagnin, M.; Longo, V.; Puukilainen, E.; Wanzenboeck, H.D.; Kessels, W.M.M.; Devi, A.; Hoffmann-Eifert, S.; Ritala, M.; Leskelä, M.

    2013-01-01

    [Zr(NEtMe)2(guan-NEtMe2)2], a recently developed compound, was investigated as a novel precursor for the atomic layer deposition (ALD) of ZrO2. With water as the oxygen source, the growth rate remained constant over a wide temperature range, whereas with ozone the growth rate increased steadily with

  16. Virtual Reality: Principles and Applications

    OpenAIRE

    MÉRIENNE , Frédéric

    2017-01-01

    Virtual reality aims at immersing a user in a virtual environment. Dedicated virtual reality technologies of human–computer interaction enable to make the link between the user and a virtual environment in capturing the user’s motion, acting on his senses as well as computing the virtual experience in real-time. The immersion in virtual environment is evaluated through the user’s perception and reaction. Virtual reality is used in a large variety of application domains which need multisensory...

  17. Coloured Petri Nets and the Invariant Method

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1981-01-01

    processes to be described by a common subnet, without losing the ability to distinguish between them. Our generalization, called coloured Petri nets, is heavily influenced by predicate transition-nets introduced by H.J. Genrich and K. Lautenbach. Moreover our paper shows how the invariant-method, introduced...... for Petri nets by K. Lautenbach, can be generalized to coloured Petri nets....

  18. Numerical study on the hydrodynamic characteristics of biofouled full-scale net cage

    Science.gov (United States)

    Bi, Chun-wei; Zhao, Yun-peng; Dong, Guo-hai

    2015-06-01

    The effect of biofouling on the hydrodynamic characteristics of the net cage is of particular interest as biofouled nettings can significantly reduce flow of well-oxygenated water reaching the stocked fish. For computational efficiency, the porous-media fluid model is proposed to simulate flow through the biofouled plane net and full-scale net cage. The porous coefficients of the porous-media fluid model can be determined from the quadratic-function relationship between the hydrodynamic forces on a plane net and the flow velocity using the least squares method. In this study, drag forces on and flow fields around five plane nets with different levels of biofouling are calculated by use of the proposed model. The numerical results are compared with the experimental data of Swift et al. (2006) and the effectiveness of the numerical model is presented. On that basis, flow through full-scale net cages with the same level of biofouling as the tested plane nets are modeled. The flow fields inside and around biofouled net cages are analyzed and the drag force acting on a net cage is estimated by a control volume analysis method. According to the numerical results, empirical formulas of reduction in flow velocity and load on a net cage are derived as function of drag coefficient of the corresponding biofouled netting.

  19. [Virtual reality in neurosurgery].

    Science.gov (United States)

    Tronnier, V M; Staubert, A; Bonsanto, M M; Wirtz, C R; Kunze, S

    2000-03-01

    Virtual reality enables users to immerse themselves in a virtual three-dimensional world and to interact in this world. The simulation is different from the kind in computer games, in which the viewer is active but acts in a nonrealistic world, or on the TV screen, where we are passively driven in an active world. In virtual reality elements look realistic, they change their characteristics and have almost real-world unpredictability. Virtual reality is not only implemented in gambling dens and the entertainment industry but also in manufacturing processes (cars, furniture etc.), military applications and medicine. Especially the last two areas are strongly correlated, because telemedicine or telesurgery was originated for military reasons to operate on war victims from a secure distance or to perform surgery on astronauts in an orbiting space station. In medicine and especially neurosurgery virtual-reality methods are used for education, surgical planning and simulation on a virtual patient.

  20. Transforming Virtual Teams

    DEFF Research Database (Denmark)

    Bjørn, Pernille

    2005-01-01

    Investigating virtual team collaboration in industry using grounded theory this paper presents the in-dept analysis of empirical work conducted in a global organization of 100.000 employees where a global virtual team with participants from Sweden, United Kingdom, Canada, and North America were...... studied. The research question investigated is how collaboration is negotiated within virtual teams? This paper presents findings concerning how collaboration is negotiated within a virtual team and elaborate the difficulties due to invisible articulation work and managing multiple communities...... in transforming the virtual team into a community. It is argued that translucence in communication structures within the virtual team and between team and management is essential for engaging in a positive transformation process of trustworthiness supporting the team becoming a community, managing the immanent...

  1. Agreements in Virtual Organizations

    Science.gov (United States)

    Pankowska, Malgorzata

    This chapter is an attempt to explain the important impact that contract theory delivers with respect to the concept of virtual organization. The author believes that not enough research has been conducted in order to transfer theoretical foundations for networking to the phenomena of virtual organizations and open autonomic computing environment to ensure the controllability and management of them. The main research problem of this chapter is to explain the significance of agreements for virtual organizations governance. The first part of this chapter comprises explanations of differences among virtual machines and virtual organizations for further descriptions of the significance of the first ones to the development of the second. Next, the virtual organization development tendencies are presented and problems of IT governance in highly distributed organizational environment are discussed. The last part of this chapter covers analysis of contracts and agreements management for governance in open computing environments.

  2. D.NET case study

    International Development Research Centre (IDRC) Digital Library (Canada)

    lremy

    The mission was defined to build, “A society where information and ... innovative ideas and projects around different themes (using ICT), and piloting them to test .... like D.Net with several projects that had moved beyond their pilot phase.

  3. Petri Nets in Cryptographic Protocols

    DEFF Research Database (Denmark)

    Crazzolara, Federico; Winskel, Glynn

    2001-01-01

    A process language for security protocols is presented together with a semantics in terms of sets of events. The denotation of process is a set of events, and as each event specifies a set of pre and postconditions, this denotation can be viewed as a Petri net. By means of an example we illustrate...

  4. Complexity metrics for workflow nets

    NARCIS (Netherlands)

    Lassen, K.B.; Aalst, van der W.M.P.

    2009-01-01

    Process modeling languages such as EPCs, BPMN, flow charts, UML activity diagrams, Petri nets, etc., are used to model business processes and to configure process-aware information systems. It is known that users have problems understanding these diagrams. In fact, even process engineers and system

  5. Reference Guide Microsoft.NET

    NARCIS (Netherlands)

    Zee M van der; Verspaij GJ; Rosbergen S; IMP; NMD

    2003-01-01

    Met behulp van het rapport kunnen ontwikkelaars, beheerders en betrokken managers bij ICT projecten meer inzicht krijgen in de .NET technologie en een goede keuze maken in de inzetbaarheid van deze technologie. Het rapport geeft de bevindingen en conclusies van een verkennende studie naar het

  6. Complexity Metrics for Workflow Nets

    DEFF Research Database (Denmark)

    Lassen, Kristian Bisgaard; van der Aalst, Wil M.P.

    2009-01-01

    Process modeling languages such as EPCs, BPMN, flow charts, UML activity diagrams, Petri nets, etc.\\ are used to model business processes and to configure process-aware information systems. It is known that users have problems understanding these diagrams. In fact, even process engineers and system...

  7. Communicating with the Net Generation

    Science.gov (United States)

    2011-03-11

    resource investment is necessary to sustain a high quality all-volunteer force. 9 Leadership Technique for the Net Generation Army Regulation 600...Generations at Work, Millenials at Work, http://www.generationsatwork. com /articles_millennials_at_work.php (accessed November 21, 2010). 31 Thomas

  8. Net Neutrality in the Netherlands

    NARCIS (Netherlands)

    van Eijk, N.

    2014-01-01

    The Netherlands is among the first countries that have put specific net neutrality standards in place. The decision to implement specific regulation was influenced by at least three factors. The first was the prevailing social and academic debate, partly due to developments in the United States. The

  9. Surgery for GEP-NETs

    DEFF Research Database (Denmark)

    Knigge, Ulrich; Hansen, Carsten Palnæs

    2012-01-01

    Surgery is the only treatment that may cure the patient with gastroentero-pancreatic (GEP) neuroendocrine tumours (NET) and neuroendocrine carcinomas (NEC) and should always be considered as first line treatment if R0/R1 resection can be achieved. The surgical and interventional procedures for GEP...

  10. Net4Care PHMR Tutorial

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    Goal To demonstrate how to use the Net4Care PHMR builder module to a) Create a SimpleClinicalDocument instance and populate it with relevant administrative and medical information to form a tele medical report of a set of measurements, b) Use the provided DanishPHMRBuilder to generate a correctly...

  11. The water footprint of agricultural products in European river basins

    International Nuclear Information System (INIS)

    Vanham, D; Bidoglio, G

    2014-01-01

    This work quantifies the agricultural water footprint (WF) of production (WF prod, agr ) and consumption (WF cons, agr ) and the resulting net virtual water import (netVW i, agr ) of 365 European river basins for a reference period (REF, 1996–2005) and two diet scenarios (a healthy diet based upon food-based dietary guidelines (HEALTHY) and a vegetarian (VEG) diet). In addition to total (tot) amounts, a differentiation is also made between the green (gn), blue (bl) and grey (gy) components. River basins where the REF WF cons, agr, tot exceeds the WF prod, agr, tot (resulting in positive netVW i, agr, tot values), are found along the London–Milan axis. These include the Thames, Scheldt, Meuse, Seine, Rhine and Po basins. River basins where the WF prod, agr, tot exceeds the WF cons, agr, tot are found in Western France, the Iberian Peninsula and the Baltic region. These include the Loire, Ebro and Nemunas basins. Under the HEALTHY diet scenario, the WF cons, agr, tot of most river basins decreases (max −32%), although it was found to increase in some basins in northern and eastern Europe. This results in 22 river basins, including the Danube, shifting from being net VW importers to being net VW exporters. A reduction (max −46%) in WF cons, agr, tot is observed for all but one river basin under the VEG diet scenario. In total, 50 river basins shift from being net VW importers to being net exporters, including the Danube, Seine, Rhone and Elbe basins. Similar observations are made when only the gn + bl and gn components are assessed. When analysing only the bl component, a different river basin pattern is observed. (letters)

  12. Virtual currencies : Real opportunities?

    OpenAIRE

    Selldahl, Sara

    2013-01-01

    AbstractThe European Central Bank defines virtual currencies as ”unregulated, digital money, which is issued and usuallycontrolled by its developers, and used and accepted among the members of a specific virtual community.”(European Central Bank, 2012, p. 5) The interest in virtual currencies has increased immensely over the last fewyears as they become increasingly prevalent in our society across many different industries. Up until now, the field ofvirtual currencies has been mainly uncharte...

  13. Real and virtual radiation

    International Nuclear Information System (INIS)

    Wolynec, E.

    1988-01-01

    Electrodisintegration cross sections related to the corresponding photonuclear process through virtual-photon spectra. A brief review of virtual-photon theory is presented. Calculations of DWBA virtual-photon spectra for finite nuclei are compared with experimental results. The multipole decomposition of electrodisintegration cross sections using these spectra is discussed and several experimental results are presented. A brief review for the bremsstrahlung cross section is also presented. (author) [pt

  14. Virtual Campus Hub technology

    DEFF Research Database (Denmark)

    Vercoulen, Frank; Badger, Merete; Monaco, Lucio

    This deliverable briefly describes which technological components have been delivered for the Virtual Campus Hub and how they can be used. A detailed discussion of the technical details of the components, how they were realized and how they fit the VCH concept can be found in deliverables D5.......4. Virtual Campus Hub Technology Evaluation Report and D6.7 The Virtual Campus Hub Concept....

  15. High availability using virtualization

    International Nuclear Information System (INIS)

    Calzolari, Federico; Arezzini, Silvia; Ciampa, Alberto; Mazzoni, Enrico; Domenici, Andrea; Vaglini, Gigliola

    2010-01-01

    High availability has always been one of the main problems for a data center. Till now high availability was achieved by host per host redundancy, a highly expensive method in terms of hardware and human costs. A new approach to the problem can be offered by virtualization. Using virtualization, it is possible to achieve a redundancy system for all the services running on a data center. This new approach to high availability allows the running virtual machines to be distributed over a small number of servers, by exploiting the features of the virtualization layer: start, stop and move virtual machines between physical hosts. The 3RC system is based on a finite state machine, providing the possibility to restart each virtual machine over any physical host, or reinstall it from scratch. A complete infrastructure has been developed to install operating system and middleware in a few minutes. To virtualize the main servers of a data center, a new procedure has been developed to migrate physical to virtual hosts. The whole Grid data center SNS-PISA is running at the moment in virtual environment under the high availability system.

  16. Secure Virtual Enclaves

    National Research Council Canada - National Science Library

    Shands, Deborah

    2002-01-01

    The Secure Virtual Enclaves (SVE) collaboration infrastructure allows multiple organizations to share their distributed application resources, while respecting organizational autonomy over local resources...

  17. Virtual Environments for Training

    National Research Council Canada - National Science Library

    Stiles, R

    1998-01-01

    .... Progress on productization of the VET Training Studio software includes increased robustness for Vista virtual environment display and interaction services, a new capability to use the STEVE visual...

  18. Photon virtual bound state

    International Nuclear Information System (INIS)

    Inoue, J.; Ohtaka, K.

    2004-01-01

    We study virtual bound states in photonics, which are a vectorial extension of electron virtual bound states. The condition for these states is derived. It is found that the Mie resonant state which satisfies the condition that the size parameter is less than the angular momentum should be interpreted as a photon virtual bound state. In order to confirm the validity of the concept, we compare the photonic density of states, the width of which represents the lifetime of the photon virtual bound states, with numerical results

  19. Virtual Training Devices Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Virtual Training Devices (VTD) Laboratory at the Life Cycle Software Engineering Center, Picatinny Arsenal, provides a software testing and support environment...

  20. Virtual Reality Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Performs basic and applied research in interactive 3D computer graphics, including visual analytics, virtual environments, and augmented reality (AR). The...

  1. VIRTUAL NETWORK COMMUNICATION AND ITS IMPACT ON INTERPERSONAL RELATIONS

    Directory of Open Access Journals (Sweden)

    Сергей Николаевич Хуторной

    2013-08-01

    Full Text Available The Internet was playing an increasing role in human life. Increasingly popular sites, where visitors can interact with other visitors through this site. Becoming popular communication "online", partially displacing the real-мире. There arises a problem of Internet addiction, or dependence on the Internet, which includes not only the dependence on virtual communication in social networks, but also addiction to gambling, online games, electronic purchases, and so on. Virtual reality acts not only as an intermediary virtual communication, but also significantly affect the nature, means and methods of communication, which ultimately has a significant effect on identity, often negatively, transforming it. The article dedicated to the analysis  of intercourse in virtual reality. The specification of net communication in comparing of real social communication is researching. The concept of Internet addicion is examined.DOI: http://dx.doi.org/10.12731/2218-7405-2013-6-9

  2. Virtual VMASC: A 3D Game Environment

    Science.gov (United States)

    Manepalli, Suchitra; Shen, Yuzhong; Garcia, Hector M.; Lawsure, Kaleen

    2010-01-01

    The advantages of creating interactive 3D simulations that allow viewing, exploring, and interacting with land improvements, such as buildings, in digital form are manifold and range from allowing individuals from anywhere in the world to explore those virtual land improvements online, to training military personnel in dealing with war-time environments, and to making those land improvements available in virtual worlds such as Second Life. While we haven't fully explored the true potential of such simulations, we have identified a requirement within our organization to use simulations like those to replace our front-desk personnel and allow visitors to query, naVigate, and communicate virtually with various entities within the building. We implemented the Virtual VMASC 3D simulation of the Virginia Modeling Analysis and Simulation Center (VMASC) office building to not only meet our front-desk requirement but also to evaluate the effort required in designing such a simulation and, thereby, leverage the experience we gained in future projects of this kind. This paper describes the goals we set for our implementation, the software approach taken, the modeling contribution made, and the technologies used such as XNA Game Studio, .NET framework, Autodesk software packages, and, finally, the applicability of our implementation on a variety of architectures including Xbox 360 and PC. This paper also summarizes the result of our evaluation and the lessons learned from our effort.

  3. .net

    Directory of Open Access Journals (Sweden)

    Le Comité de Rédaction d' EspacesTemps.net

    2002-06-01

    Full Text Available EspacesTemps lance aujourd'hui deux objets différents : un site internet et, sur ce site, Le Journal . Il s'agit donc de bien plus, et, au fond, de tout autre chose qu'un simple outil de communication destiné à informer nos lecteurs de nos parutions. Ce n'est pas non plus la « mise en ligne » de nos numéros-papier. L'internet nous donne au contraire l'occasion de réaliser, dans de meilleures conditions, ce que nous avons tenté de faire depuis quelques ...

  4. Caught in the Net: Perineuronal Nets and Addiction

    Directory of Open Access Journals (Sweden)

    Megan Slaker

    2016-01-01

    Full Text Available Exposure to drugs of abuse induces plasticity in the brain and creates persistent drug-related memories. These changes in plasticity and persistent drug memories are believed to produce aberrant motivation and reinforcement contributing to addiction. Most studies have explored the effect drugs of abuse have on pre- and postsynaptic cells and astrocytes; however, more recently, attention has shifted to explore the effect these drugs have on the extracellular matrix (ECM. Within the ECM are unique structures arranged in a net-like manner, surrounding a subset of neurons called perineuronal nets (PNNs. This review focuses on drug-induced changes in PNNs, the molecules that regulate PNNs, and the expression of PNNs within brain circuitry mediating motivation, reward, and reinforcement as it pertains to addiction.

  5. Petri nets and fault diagnosis in nuclear reactors

    International Nuclear Information System (INIS)

    Jalel, N.A.; Nicholson, H.

    1990-11-01

    The possibility of applying Petri nets (Pns) as a modelling tool to represent any fault or accident that might occur in the Loss Of Fluid Test (LOFT) reactor, small scale pressurised water reactor, is discussed and analysed. Pns are developed to assist the nuclear reactor operator in identifying any fault or alarm that might arise in the power station. (author)

  6. Drag of Clean and Fouled Net Panels--Measurements and Parameterization of Fouling.

    Directory of Open Access Journals (Sweden)

    Lars Christian Gansel

    Full Text Available Biofouling is a serious problem in marine aquaculture and it has a number of negative impacts including increased forces on aquaculture structures and reduced water exchange across nets. This in turn affects the behavior of fish cages in waves and currents and has an impact on the water volume and quality inside net pens. Even though these negative effects are acknowledged by the research community and governmental institutions, there is limited knowledge about fouling related effects on the flow past nets, and more detailed investigations distinguishing between different fouling types have been called for. This study evaluates the effect of hydroids, an important fouling organism in Norwegian aquaculture, on the forces acting on net panels. Drag forces on clean and fouled nets were measured in a flume tank, and net solidity including effect of fouling were determined using image analysis. The relationship between net solidity and drag was assessed, and it was found that a solidity increase due to hydroids caused less additional drag than a similar increase caused by change in clean net parameters. For solidities tested in this study, the difference in drag force increase could be as high as 43% between fouled and clean nets with same solidity. The relationship between solidity and drag force is well described by exponential functions for clean as well as for fouled nets. A method is proposed to parameterize the effect of fouling in terms of an increase in net solidity. This allows existing numerical methods developed for clean nets to be used to model the effects of biofouling on nets. Measurements with other types of fouling can be added to build a database on effects of the accumulation of different fouling organisms on aquaculture nets.

  7. Army Net Zero Prove Out. Net Zero Energy Best Practices

    Science.gov (United States)

    2014-11-18

    recovery and cogeneration opportunities, offsetting the remaining demand with the production of renewable energy from onsite sources so that the Net...implementing energy recovery and cogeneration opportunities, and then offsetting the remaining demand with the production of renewable energy from on-site...they impact overall energy performance. The use of energy modeling in the design stage provides insights that can contribute to more effective design

  8. Army Net Zero Prove Out. Net Zero Waster Best Practices

    Science.gov (United States)

    2014-11-18

    Municipal Supply – It may be feasible for the installation to construct its own Water Treatment Plant ( WTP ) and/or Waste Water Treatment Plant...Supply – It may be feasible for the installation to construct its own Water Treatment Plant ( WTP ) and/or Waste Water Treatment Plant (WWTP) to be free

  9. Net alkalinity and net acidity 1: Theoretical considerations

    International Nuclear Information System (INIS)

    Kirby, Carl S.; Cravotta, Charles A.

    2005-01-01

    Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO 2 , and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined 'CO 2 -acidity' is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO 2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass-action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mgL -1 as CaCO 3 (based on pH and analytical concentrations of dissolved Fe II , Fe III , Mn, and Al in mgL -1 ):acidity calculated =50{1000(10 -pH )+[2(Fe II )+3(Fe III )]/56+2(Mn) /55+3(Al)/27}underestimates contributions from HSO 4 - and H + , but overestimates the acidity due to Fe 3+ and Al 3+ . However, these errors tend to approximately cancel each other. It is demonstrated that 'net alkalinity' is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the

  10. Net alkalinity and net acidity 1: Theoretical considerations

    Science.gov (United States)

    Kirby, C.S.; Cravotta, C.A.

    2005-01-01

    Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO2, and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined "CO 2-acidity" is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass- action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mg L -1 as CaCO3 (based on pH and analytical concentrations of dissolved FeII, FeIII, Mn, and Al in mg L -1):aciditycalculated=50{1000(10-pH)+[2(FeII)+3(FeIII)]/56+2(Mn)/ 55+3(Al)/27}underestimates contributions from HSO4- and H+, but overestimates the acidity due to Fe3+ and Al3+. However, these errors tend to approximately cancel each other. It is demonstrated that "net alkalinity" is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation, (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the value obtained in a

  11. A Virtual History of Mauritius

    African Journals Online (AJOL)

    admpather

    University of Mauritius, Réduit, Mauritius. 116. A Virtual History ... out will be presented. Keywords: Virtual Heritage, Virtual Reality, Archaeology, Mauritius ... money would better be spent on other major education and IT development projects ...

  12. CLIMATIC FORECASTING OF NET INFILTRATION AT YUCCA MOUNTAIN, USING ANALOGUE METEOROLOGICAL DATA

    International Nuclear Information System (INIS)

    B. Faybishenko

    2005-01-01

    Net infiltration is a key hydrologic parameter that controls the rate of deep percolation through the unsaturated zone, the groundwater recharge, radionuclide transport, and seepage into the underground tunnels. Because net infiltration is largely affected by climatic conditions, future changes in climatic conditions will potentially alter net infiltration. The objectives of this presentation are to: (1) Present a conceptual model and a semi-empirical approach for regional, climatic forecasting of net infiltration, based on the precipitation and temperature data from analogue meteorological stations, and (2) Demonstrate the results of forecasting net infiltration for future climates--interglacial, monsoon and glacial--over the Yucca Mountain region for the period of 500,000 years. Calculations of the net infiltration were performed using a modified Budyko's water-balance model, for which potential evapotranspiration was evaluated from the temperature-based Thornthwaite formula. (Both Budyko's and Thornthwaite's formulae have been used broadly in hydrological studies.) The results of calculations were used for ranking net infiltration, along with the aridity and precipitation-effectiveness (P-E) indexes, for future climatic scenarios. Using this approach, we determined a general trend of increasing net infiltration from the present-day (interglacial) climate to monsoon, intermediate (glacial transition), and then to the glacial climate. Ranking of the aridity and P-E indexes is practically the same as that of net infiltration. The validation of the computed net infiltration rates yielded a good match with other field and modeling study results of groundwater recharge and net infiltration evaluation

  13. The virtual GULLIVER project

    NARCIS (Netherlands)

    Trappl, R.; Nijholt, Antinus; Stuk, M.; Zwiers, Jakob

    2002-01-01

    In this paper we discuss our virtual reality project Gulliver. This project is part of a more comprehensive project conceived by two artists, Matjaž Štuk and Alena Hudcovicová, called “Gulliver’s Museum of Living Art��?. Our part of the project involves a virtual reality version of Swift’s Gulliver

  14. A Virtual Good Idea

    Science.gov (United States)

    Bolch, Matt

    2009-01-01

    School districts across the country have always had to do more with less. Funding goes only so far, leaving administrators and IT staff to find innovative ways to save money while maintaining a high level of academic quality. Creating virtual servers accomplishes both tasks, district technology personnel say. Virtual environments not only allow…

  15. 10 Myths of Virtualization

    Science.gov (United States)

    Schaffhauser, Dian

    2012-01-01

    Half of servers in higher ed are virtualized. But that number's not high enough for Link Alander, interim vice chancellor and CIO at the Lone Star College System (Texas). He aspires to see 100 percent of the system's infrastructure requirements delivered as IT services from its own virtualized data centers or other cloud-based operators. Back in…

  16. Designing Virtual Learning Environments

    DEFF Research Database (Denmark)

    Veirum, Niels Einar

    2003-01-01

    The main objective of this working paper is to present a conceptual model for media integrated communication in virtual learning environments. The model for media integrated communication is very simple and identifies the necessary building blocks for virtual place making in a synthesis of methods...

  17. OVERLAPPING VIRTUAL CADASTRAL DOCUMENTATION

    Directory of Open Access Journals (Sweden)

    Madalina - Cristina Marian

    2013-12-01

    Full Text Available Two cadastrale plans of buildings, can overlap virtual. Overlap is highlighted when digital reception. According to Law no. 7/1996 as amended and supplemented, to solve these problems is by updating the database graphs, the repositioning. This paper addresses the issue of overlapping virtual cadastre in the history of the period 1999-2012.

  18. Taxation of virtual currency

    NARCIS (Netherlands)

    Bal, Aleksandra Marta

    2014-01-01

    The Information Age has created a new concept of money – virtual currencies existing solely in the cyberspace in the form of intangible computer code. The most prominent virtual currency scheme, Bitcoin, grabbed the public attention as its value skyrocketed at the beginning of 2012. Whereas Bitcoin

  19. Virtual Company and Modelbank

    DEFF Research Database (Denmark)

    Thorsteinsson, Uffe

    1996-01-01

    Ansøgning til Socrates programmet vedr. Tematisk netværk inden for området Virtual Company and Modelbank......Ansøgning til Socrates programmet vedr. Tematisk netværk inden for området Virtual Company and Modelbank...

  20. Virtual Pediatric Hospital

    Science.gov (United States)

    ... Thoracopaedia - An Imaging Encyclopedia of Pediatric Thoracic Disease Virtual Pediatric Hospital is the Apprentice's Assistant™ Last revised ... pediatric resources: GeneralPediatrics.com | PediatricEducation.org | SearchingPediatrics.com Virtual Pediatric Hospital is curated by Donna M. D' ...

  1. Virtual School Counseling

    Science.gov (United States)

    Osborn, Debra S.; Peterson, Gary W.; Hale, Rebecca R.

    2015-01-01

    The advent of virtual schools opens doors to opportunity for delivery of student services via the Internet. Through the use of structured interviews with four practicing Florida virtual school counselors, and a follow-up survey, the authors examined the experiences and reflections of school counselors who are employed full time in a statewide…

  2. State Virtual Libraries

    Science.gov (United States)

    Pappas, Marjorie L.

    2003-01-01

    Virtual library? Electronic library? Digital library? Online information network? These all apply to the growing number of Web-based resource collections managed by consortiums of state library entities. Some, like "INFOhio" and "KYVL" ("Kentucky Virtual Library"), have been available for a few years, but others are just starting. Searching for…

  3. Who Benefits from Virtuality?

    Science.gov (United States)

    Harper, Barry; Hedberg, John G.; Wright, Rob

    2000-01-01

    Discusses the use of constructivist frameworks to develop effective and successful learning environments, including educational software. Topics include technology supporting reform; virtuality and multimedia; attributes of interactive multimedia and virtual reality; and examples of context and learner active participation. (Contains 35…

  4. Virtual Reality in Psychology

    Science.gov (United States)

    Foreman, Nigel

    2009-01-01

    The benefits of using virtual environments (VEs) in psychology arise from the fact that movements in virtual space, and accompanying perceptual changes, are treated by the brain in much the same way as those in equivalent real space. The research benefits of using VEs, in areas of psychology such as spatial learning and cognition, include…

  5. Virtual reality musical instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj

    2016-01-01

    The rapid development and availability of low cost technologies has created a wide interest in virtual reality (VR), but how to design and evaluate multisensory interactions in VR remains as a challenge. In this paper, we focus on virtual reality musical instruments, present an overview of our...

  6. Virtual Seminar Room

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Fosgerau, Anders; Hansen, Peter Søren Kirk

    1999-01-01

    The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented.......The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented....

  7. Virtual Peace Education

    Science.gov (United States)

    Firer, Ruth

    2008-01-01

    This article is based on the convictions that peace education is the basis for any sustainable non-violent relations between parties in a conflict, and that virtual peace education is almost the only feasible way to practise peace education in an open violent conflict as is the current Israeli/Palestinians one. Moreover, virtual peace education…

  8. Representing Large Virtual Worlds

    NARCIS (Netherlands)

    Kol, T.R.

    2018-01-01

    The ubiquity of large virtual worlds and their growing complexity in computer graphics require efficient representations. This means that we need smart solutions for the underlying storage of these complex environments, but also for their visualization. How the virtual world is best stored and how

  9. VEM: Virtual Enterprise Methodology

    DEFF Research Database (Denmark)

    Tølle, Martin; Vesterager, Johan

    2003-01-01

    This chapter presents a virtual enterprise methodology (VEM) that outlines activities to consider when setting up and managing virtual enterprises (VEs). As a methodology the VEM helps companies to ask the right questions when preparing for and setting up an enterprise network, which works...

  10. The Erasmus Virtual Campus

    Science.gov (United States)

    Isakeit, D.

    2002-02-01

    The Erasmus Virtual Campus was inaugurated in September 2000 to bring together scientists and engineers interested in using the International Space Station and other facilities for their research. It also provides the foundation for creating Virtual Institutes in selected scientific disciplines. The current capabilities of the Campus are highlighted, along with plans for the future.

  11. Les dispositifs du Net art

    OpenAIRE

    Fourmentraux, Jean-Paul

    2010-01-01

    La pratique du Net art radicalise la question du potentiel communicationnel d’un média —Internet— qui constitue tout à la fois le support technique, l’outil créatif et le dispositif social de l’œuvre. Les technologies de l’information et de la communication (TIC) placent en effet l’œuvre d’art au cœur d’une négociation socialement distribuée entre l’artiste et le public. L’article est focalisé sur cette construction collective du Net art et sur ses mises en scènes. Il montre le travail artist...

  12. Complexity Metrics for Workflow Nets

    DEFF Research Database (Denmark)

    Lassen, Kristian Bisgaard; van der Aalst, Wil M.P.

    2009-01-01

    analysts have difficulties grasping the dynamics implied by a process model. Recent empirical studies show that people make numerous errors when modeling complex business processes, e.g., about 20 percent of the EPCs in the SAP reference model have design flaws resulting in potential deadlocks, livelocks......, etc. It seems obvious that the complexity of the model contributes to design errors and a lack of understanding. It is not easy to measure complexity, however. This paper presents three complexity metrics that have been implemented in the process analysis tool ProM. The metrics are defined...... for a subclass of Petri nets named Workflow nets, but the results can easily be applied to other languages. To demonstrate the applicability of these metrics, we have applied our approach and tool to 262 relatively complex Protos models made in the context of various student projects. This allows us to validate...

  13. WE-NET Hydrogen Energy Symposium proceedings; WE-NET suiso energy symposium koen yokoshu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-24

    The research and development of WE-NET (World Energy Network) was started in 1993 as a NEDO (New Energy and Industrial Technology Development Organization) project in the New Sunshine Program of Agency of Industrial Science and Technology, Ministry of International Trade and Industry, and aims to contribute to the improvement of global environment and to ease the difficult energy supply/demand situation. The ultimate goal of WE-NET is the construction of a global-scale clean energy network in which hydrogen will be produced from renewable energies such as water and sunshine for distribution to energy consuming locations. Experts are invited to the Symposium from the United States, Germany, and Canada. Information is collected from the participants on hydrogen energy technology development in the three countries, the result of the Phase I program of WE-NET is presented to hydrogen energy scientists in Japan, and views and opinions on the project are collected from them. Accommodated in the above-named publication are 30 essays and three special lectures delivered at the Symposium. (NEDO)

  14. Virtual Manufacturing Techniques Designed and Applied to Manufacturing Activities in the Manufacturing Integration and Technology Branch

    Science.gov (United States)

    Shearrow, Charles A.

    1999-01-01

    One of the identified goals of EM3 is to implement virtual manufacturing by the time the year 2000 has ended. To realize this goal of a true virtual manufacturing enterprise the initial development of a machinability database and the infrastructure must be completed. This will consist of the containment of the existing EM-NET problems and developing machine, tooling, and common materials databases. To integrate the virtual manufacturing enterprise with normal day to day operations the development of a parallel virtual manufacturing machinability database, virtual manufacturing database, virtual manufacturing paradigm, implementation/integration procedure, and testable verification models must be constructed. Common and virtual machinability databases will include the four distinct areas of machine tools, available tooling, common machine tool loads, and a materials database. The machine tools database will include the machine envelope, special machine attachments, tooling capacity, location within NASA-JSC or with a contractor, and availability/scheduling. The tooling database will include available standard tooling, custom in-house tooling, tool properties, and availability. The common materials database will include materials thickness ranges, strengths, types, and their availability. The virtual manufacturing databases will consist of virtual machines and virtual tooling directly related to the common and machinability databases. The items to be completed are the design and construction of the machinability databases, virtual manufacturing paradigm for NASA-JSC, implementation timeline, VNC model of one bridge mill and troubleshoot existing software and hardware problems with EN4NET. The final step of this virtual manufacturing project will be to integrate other production sites into the databases bringing JSC's EM3 into a position of becoming a clearing house for NASA's digital manufacturing needs creating a true virtual manufacturing enterprise.

  15. dotNet som multimediaplattform

    OpenAIRE

    Johansson, Glenn

    2008-01-01

    As the speed and complexity of computers have increased so have software and the expectations of users. Software development follows a straightforward evolution where complicated tasks are made easier by better tools; this repeats itself as those tasks in turn are automated. Software mechanics that were seen as revolutionary a decade ago are seen as obvious requirements that no multimedia application can be without. dotNet is the next step in line and makes it easier and faster to build softw...

  16. Organization Virtual or Networked?

    Directory of Open Access Journals (Sweden)

    Rūta Tamošiūnaitė

    2013-08-01

    Full Text Available Purpose—to present distinction between “virtual organization” and “networked organization”; giving their definitions.Design/methodology/approach—review of previous researches, systemic analyses of their findings and synthesis of distinctive characteristics of ”virtual organization” and “networked organization.”Findings—the main result of the research is key diverse features separating ”virtual organization” and ”networked organization.” Definitions of “virtual organization” and “networked organization” are presented.Originality/Value—distinction between “virtual organization” and “networked organization” creates possibilities to use all advantages of those types of organizations and gives foundation for deeper researches in this field.Research type: general review.

  17. Designing Virtual Worlds

    DEFF Research Database (Denmark)

    Gürsimsek, Remzi Ates

    2014-01-01

    The online social platforms known as virtual worlds present their users various affordances for avatar based co-presence, social interaction and provide tools for collaborative content creation, including objects, textures and animations. The users of these worlds navigate their avatars as personal...... the audio-visual characteristics of designing in multi-user virtual environments generate experiential, interpersonal and textual meaning potentials....... mediators in 3D virtual space to collaborate and co-design the digital content. These co-designers are also the residents of these worlds, as they socialize by building inworld friendships. This article presents a social semiotic analysis of the three-dimensional virtual places and artifacts in the virtual...

  18. NET model coil test possibilities

    International Nuclear Information System (INIS)

    Erb, J.; Gruenhagen, A.; Herz, W.; Jentzsch, K.; Komarek, P.; Lotz, E.; Malang, S.; Maurer, W.; Noether, G.; Ulbricht, A.; Vogt, A.; Zahn, G.; Horvath, I.; Kwasnitza, K.; Marinucci, C.; Pasztor, G.; Sborchia, C.; Weymuth, P.; Peters, A.; Roeterdink, A.

    1987-11-01

    A single full size coil for NET/INTOR represents an investment of the order of 40 MUC (Million Unit Costs). Before such an amount of money or even more for the 16 TF coils is invested as much risks as possible must be eliminated by a comprehensive development programme. In the course of such a programme a coil technology verification test should finally prove the feasibility of NET/INTOR TF coils. This study report is almost exclusively dealing with such a verification test by model coil testing. These coils will be built out of two Nb 3 Sn-conductors based on two concepts already under development and investigation. Two possible coil arrangements are discussed: A cluster facility, where two model coils out of the two Nb 3 TF-conductors are used, and the already tested LCT-coils producing a background field. A solenoid arrangement, where in addition to the two TF model coils another model coil out of a PF-conductor for the central PF-coils of NET/INTOR is used instead of LCT background coils. Technical advantages and disadvantages are worked out in order to compare and judge both facilities. Costs estimates and the time schedules broaden the base for a decision about the realisation of such a facility. (orig.) [de

  19. NET-2 Network Analysis Program

    International Nuclear Information System (INIS)

    Malmberg, A.F.

    1974-01-01

    The NET-2 Network Analysis Program is a general purpose digital computer program which solves the nonlinear time domain response and the linearized small signal frequency domain response of an arbitrary network of interconnected components. NET-2 is capable of handling a variety of components and has been applied to problems in several engineering fields, including electronic circuit design and analysis, missile flight simulation, control systems, heat flow, fluid flow, mechanical systems, structural dynamics, digital logic, communications network design, solid state device physics, fluidic systems, and nuclear vulnerability due to blast, thermal, gamma radiation, neutron damage, and EMP effects. Network components may be selected from a repertoire of built-in models or they may be constructed by the user through appropriate combinations of mathematical, empirical, and topological functions. Higher-level components may be defined by subnetworks composed of any combination of user-defined components and built-in models. The program provides a modeling capability to represent and intermix system components on many levels, e.g., from hole and electron spatial charge distributions in solid state devices through discrete and integrated electronic components to functional system blocks. NET-2 is capable of simultaneous computation in both the time and frequency domain, and has statistical and optimization capability. Network topology may be controlled as a function of the network solution. (U.S.)

  20. Virtual Organizations: Beyond Network Organization

    Directory of Open Access Journals (Sweden)

    Liviu Gabriel CRETU

    2006-01-01

    Full Text Available One of the most used buzz-words in (e-business literature of the last decade is virtual organization. The term "virtual" can be identified in all sorts of combinations regarding the business world. From virtual products to virtual processes or virtual teams, everything that is “touched” by the computer’s processing power instantly becomes virtual. Moreover, most of the literature treats virtual and network organizations as being synonyms. This paper aims to draw a much more distinctive line between the two concepts. Providing a more coherent description of what virtual organization might be is also one of our intentions.