WorldWideScience

Sample records for gaz periode 2009-2020

  1. Multi-annual planning of investments for heat production. 2009 - 2020 period

    International Nuclear Information System (INIS)

    2005-01-01

    A new Multi-annual Planning of Investments (PPI) for heat production in France has been realized in order to meet the conclusions of the Grenelle Environnement Forum for a better energy efficiency and a larger use of renewable energies. Based on quantitative data (the increase in heat production will reach more than 10 Mtoe by 2020), potential objectives have been assessed for the various heat production sources and techniques: wood, biomass (for buildings, district heating, industry and processes, cogeneration), deep and intermediary geothermal energy, individual heat pumps, individual and collective heat solar systems, biogas, etc. These objectives are said to be ambitious but reachable if every sources and techniques are thoroughly exploited

  2. Natural gas news; Gaz actualites

    Energy Technology Data Exchange (ETDEWEB)

    Anon,

    1998-12-01

    This brochure is a compilation of practical information concerning the Gaz de France group: organization chart, daughter companies, services, economical activity, natural gas market, trade, regulations etc. A list of partners, directions, centres, groups, associations and other various organisms in relation with Gaz de France company is given. (J.S.)

  3. Gaz de France. Operation note

    International Nuclear Information System (INIS)

    2003-01-01

    This note was published for the public at the occasion of the admission to Euronext's Eurolist of the existing shares that make the capital of Gaz de France company, the French gas utility. The note gives some informations about Gaz de France activity, and about its strategy of development in the European gas market. Then it describes the offer relative to the opening of Gaz de France capital. Some selected financial data and some precision about the risk factors and the management of the company complete the document. (J.S.)

  4. Gaz de France. Source document

    International Nuclear Information System (INIS)

    2005-01-01

    This document was issued by Gaz de France, the French gas utility, at the occasion of the opening of the capital of the company. It is intended to shareholders and presents some informations relative to the stocks admitted to Euronext's Eurolist, some general informations about the company and its capital, some informations about the activities of Gaz de France group, about its financial situation and results, about its management, and about its recent evolution and future perspectives. (J.S.)

  5. Gaz de France interim financial report 2007

    International Nuclear Information System (INIS)

    2007-01-01

    This financial report contains the unaudited condensed financial statements of Gaz de France Group for the first half ended June 30, 2007, which were reviewed by the audit committee on August 27, 2007 and by the board of directors at its meeting on August 28, 2007. It includes forward-looking statements concerning the objectives, strategies, financial position, future operating results and the operations of Gaz de France Group. These statements reflect the Group's current perception of its activities and the markets in which it operates, as well as various estimates and assumptions considered to be reasonable. Content: interim management report (highlights of the first half of 2007, revenues and results for the period, financial structure, data on outstanding stock, outlook); interim consolidated financial statements (consolidated statements of income, consolidated balance sheets, consolidated statements of cash flows, recognized income and expenses, statements of changes in shareholders' equity, note to the consolidated financial statements); statement by the person responsible for the interim financial report; statutory auditors' report. (J.S.)

  6. Pluri annual indicative plan of the investments in the gas sector; Plan indicatif pluriannuel des investissements dans le secteur du gaz Periode 2006-2015

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-03-15

    This indicative plan constitutes the first report to the Parliament. It is a prospective document for the period 2006-2015 containing: a forecast of the gas demand increase, a description of main investments decided in matter of gas infrastructures, a diagnostic concerning the adequation between the supplying capacities in natural gas and the national needs, a series of recommendations on the State tools to guarantee the national supplying security and on the investment. The four parts deal with the stakes and perspectives of the national natural gas supplying, the demand evolution, the offer evolution and the equilibrium offer. (A.L.B.)

  7. Gaz de France. Operation note; Gaz de France. Note d'operation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This note was published for the public at the occasion of the admission to Euronext's Eurolist of the existing shares that make the capital of Gaz de France company, the French gas utility. The note gives some informations about Gaz de France activity, and about its strategy of development in the European gas market. Then it describes the offer relative to the opening of Gaz de France capital. Some selected financial data and some precision about the risk factors and the management of the company complete the document. (J.S.)

  8. Gaz de France annual report 2003

    International Nuclear Information System (INIS)

    2003-01-01

    Today, Gaz de France Group ranks as one of the largest gas utilities in Europe. This success is the fruit of a growth strategy that fuses economic, social and environmental imperatives. To respond more efficiently to fluctuations in the natural gas market and continue to expand its range of competitive products and services, Gaz de France has committed to integrated development across the full spectrum of natural gas activities, from exploration and production to the sale of energy and related services. As the leading supplier of natural gas in France, Gaz de France has honed a targeted policy to acquire equity interests and assets, mainly in Europe, assuring the Group of a privileged place at the heart of the European gas grid. As European energy markets continue to open more widely to competition, the Group intends to benefit from its presence in all the sectors of the natural gas industry and in the European market to confirm its position as an integrated energy operator, focused on gas, among Europe's leaders. To achieve this goal, Gaz de France will concentrate in a balanced fashion on activities linked to infrastructures and activities related to energy supply and services. While assuming its public service responsibilities, the Group will expand the range of products and services to customers. This activity report presents: consolidated financial highlights, profile, corporate governance, Gaz de France's ambition, panorama of activities: energy supply and services (exploration - production, purchase and sale of energy, services), infrastructures (transmission and storage - France, distribution - France, transmission and distribution - international), Commitments of Gaz de France (human resources, research and development, sustainable development, map of main subsidiaries and affiliates)

  9. Gaz de France. Source document; Gaz de France. Document de base

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This document was issued by Gaz de France, the French gas utility, at the occasion of the opening of the capital of the company. It is intended to shareholders and presents some informations relative to the stocks admitted to Euronext's Eurolist, some general informations about the company and its capital, some informations about the activities of Gaz de France group, about its financial situation and results, about its management, and about its recent evolution and future perspectives. (J.S.)

  10. Gaz de France annual report 2001

    International Nuclear Information System (INIS)

    2001-01-01

    One of Europe's leading gas utilities, the Gaz de France Group operates in all sectors of the natural gas industry, from exploration and production to energy distribution and services, to respond to customer demand efficiently and achieve sustained and profitable growth. To this end, the Group is organized in five lines of business: exploration and production, supply and trading, transmission, distribution and services. Active in 33 countries, the Gaz de France Group first targets growth in Europe, its natural environment. The opening of energy markets and its position at the center of Europe's gas grids offers the Group many opportunities in trading, transmission for third parties, distribution and services. Since August 10, 2000, Gaz de France has made it possible for other gas operators to access its transmission system. The Group capitalizes on its expertise at the global level as well, in emerging markets like Mexico and in fields in which it has recognized know-how, such as liquefied natural gas (LNG). To ensure this growth and pursue its penetration of European and world markets, the Gaz de France Group implements a policy of cooperation and partnership with other energy sector operators, demonstrates its well-developed ability to innovate and practices a customer-focused organization that offers competitive, tailored services to residential users, companies and local governments. The Group has chosen to pursue this growth through a strategy of sustainable development. By making natural gas more accessible and promoting its uses, Gaz de France integrates demand-side management of energy, fosters human development and ensures environmental protection in France, Europe and the world. This activity report presents: the corporate profile of the group, the international natural gas businesses, the financial highlights, the growth objectives of the group in all its businesses (exploration and production, supply and trading, transmission, distribution, services

  11. Gaz de France annual report 2003; Gaz de France rapport annuel 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Today, Gaz de France Group ranks as one of the largest gas utilities in Europe. This success is the fruit of a growth strategy that fuses economic, social and environmental imperatives. To respond more efficiently to fluctuations in the natural gas market and continue to expand its range of competitive products and services, Gaz de France has committed to integrated development across the full spectrum of natural gas activities, from exploration and production to the sale of energy and related services. As the leading supplier of natural gas in France, Gaz de France has honed a targeted policy to acquire equity interests and assets, mainly in Europe, assuring the Group of a privileged place at the heart of the European gas grid. As European energy markets continue to open more widely to competition, the Group intends to benefit from its presence in all the sectors of the natural gas industry and in the European market to confirm its position as an integrated energy operator, focused on gas, among Europe's leaders. To achieve this goal, Gaz de France will concentrate in a balanced fashion on activities linked to infrastructures and activities related to energy supply and services. While assuming its public service responsibilities, the Group will expand the range of products and services to customers. This activity report presents: consolidated financial highlights, profile, corporate governance, Gaz de France's ambition, panorama of activities: energy supply and services (exploration - production, purchase and sale of energy, services), infrastructures (transmission and storage - France, distribution - France, transmission and distribution - international), Commitments of Gaz de France (human resources, research and development, sustainable development, map of main subsidiaries and affiliates)

  12. Gaz de France annual report 2000

    International Nuclear Information System (INIS)

    2000-01-01

    A leader in the natural gas market in Europe, Gaz de France is an integrated group active in all sectors of the natural gas industry. In exploration and production, trading of natural gas, transmission, storage, distribution, energy management, air conditioning and heating, the Group has developed recognized skills and know-how both upstream and down to assure its customers of diversified, efficient and competitive services. A leader in liquefied natural gas, storage and distribution technologies, the Gaz de France Group has strong positions in Europe and operates throughout the world by promoting a strategy of alliances and partnerships at all levels of the gas industry. The goal of the Gaz de France Group is to continue to expand and develop its activities from the wellhead to the burner tip, and to seize, in France and throughout the world, the best opportunities offered to capitalize on its strengths. This activity report presents: the corporate profile, the financial highlights, the principal subsidiaries and affiliates, the major European trunk lines the responsive, customer-focused services (exploration-production, trading, transmission, distribution, services), the actions to ensure performance (productive research, comprehensive quality assurance, mobilized workforce ready for the opening of the markets)

  13. Gaz de France 2006 sustainable development report

    International Nuclear Information System (INIS)

    2006-01-01

    A major European energy utility, the Gaz de France Group produces, purchases, transports, distributes and sells natural gas, electricity and related services for its residential, corporate and local government customers. this report presents the actions implemented by the group to incorporate sustainable development into its strategy. From the point of view of risks and opportunities, the group analyzes what it takes to ensure development that respects people and the environment, and it implements them in all its business lines and management systems. Content: Gaz de France, portrait of a major energy utility, highlights of 2006, challenges and strategy (defining strategy and sustainable development policy, specific risks and opportunities, activities of the Gaz de France group: challenges, impact for stakeholders, transparency and independence in governing), ranking and implementing (defining sustainable development policy: reviewing priorities, meeting all the challenges, publicizing and defending positions, increasing awareness, overseeing and monitoring results), results of the 2004-2006 sustainable development action plan, dialogue and action with stakeholders, performance assessment, performance in response to challenges: energy challenges (guaranteeing regular supplies, controlling atmospheric emissions, promoting energy conservation, developing renewable energy), industrial challenges (ensuring health and safety, limiting the overall environmental impact of group activities), social responsibility challenges (advocating corporate social responsibility, promoting human rights and fighting corruption, encouraging commitment to solidarity, promoting regional development through local initiatives, reconciling acquisitions, procurement and sustainable development, ensuring transparency in natural gas rates, providing shareholders with quality information, promoting diversity, a source of enrichment, making working conditions a performance factor), indicators and

  14. Gaz de France annual report 2001; Gaz de France rapport annuel 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    One of Europe's leading gas utilities, the Gaz de France Group operates in all sectors of the natural gas industry, from exploration and production to energy distribution and services, to respond to customer demand efficiently and achieve sustained and profitable growth. To this end, the Group is organized in five lines of business: exploration and production, supply and trading, transmission, distribution and services. Active in 33 countries, the Gaz de France Group first targets growth in Europe, its natural environment. The opening of energy markets and its position at the center of Europe's gas grids offers the Group many opportunities in trading, transmission for third parties, distribution and services. Since August 10, 2000, Gaz de France has made it possible for other gas operators to access its transmission system. The Group capitalizes on its expertise at the global level as well, in emerging markets like Mexico and in fields in which it has recognized know-how, such as liquefied natural gas (LNG). To ensure this growth and pursue its penetration of European and world markets, the Gaz de France Group implements a policy of cooperation and partnership with other energy sector operators, demonstrates its well-developed ability to innovate and practices a customer-focused organization that offers competitive, tailored services to residential users, companies and local governments. The Group has chosen to pursue this growth through a strategy of sustainable development. By making natural gas more accessible and promoting its uses, Gaz de France integrates demand-side management of energy, fosters human development and ensures environmental protection in France, Europe and the world. This activity report presents: the corporate profile of the group, the international natural gas businesses, the financial highlights, the growth objectives of the group in all its businesses (exploration and production, supply and trading, transmission, distribution, services

  15. Gaz de France annual report 2001; Gaz de France rapport annuel 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    One of Europe's leading gas utilities, the Gaz de France Group operates in all sectors of the natural gas industry, from exploration and production to energy distribution and services, to respond to customer demand efficiently and achieve sustained and profitable growth. To this end, the Group is organized in five lines of business: exploration and production, supply and trading, transmission, distribution and services. Active in 33 countries, the Gaz de France Group first targets growth in Europe, its natural environment. The opening of energy markets and its position at the center of Europe's gas grids offers the Group many opportunities in trading, transmission for third parties, distribution and services. Since August 10, 2000, Gaz de France has made it possible for other gas operators to access its transmission system. The Group capitalizes on its expertise at the global level as well, in emerging markets like Mexico and in fields in which it has recognized know-how, such as liquefied natural gas (LNG). To ensure this growth and pursue its penetration of European and world markets, the Gaz de France Group implements a policy of cooperation and partnership with other energy sector operators, demonstrates its well-developed ability to innovate and practices a customer-focused organization that offers competitive, tailored services to residential users, companies and local governments. The Group has chosen to pursue this growth through a strategy of sustainable development. By making natural gas more accessible and promoting its uses, Gaz de France integrates demand-side management of energy, fosters human development and ensures environmental protection in France, Europe and the world. This activity report presents: the corporate profile of the group, the international natural gas businesses, the financial highlights, the growth objectives of the group in all its businesses (exploration and production, supply and trading, transmission, distribution

  16. Gaz de France. 2006 reference document

    International Nuclear Information System (INIS)

    2006-01-01

    This document was issued by Gaz de France, the French gas utility, at the occasion of the opening of the capital of the company. It is intended to shareholders and presents the relevant informations relative to the annual consolidated financial statements of the group according to IFRS and French standards for the year 2005 (selected financial information, business overview, liquidity and capital resources, profit forecasts or estimates, compensation and benefits, issuer assets etc..). It includes also some complementary information about the activities of the group, its estate property, plants and equipments, its R and D and patenting activities, its management and administration, its 2005 and 2006 contracts etc.. (J.S.)

  17. Gaz de France 2006 annual report

    International Nuclear Information System (INIS)

    2006-01-01

    Gaz de France is major European energy utility, which produces, purchases, transports, distributes and sells natural gas, electricity and related services for its residential, corporate and local government customers. Its strategic focuses are to develop an ambitious marketing strategy, pursue a supply and procurement policy that guarantees the Group's competitiveness, confirm its position as a benchmark infrastructure manager, and speed up its profitable growth in Europe. Gaz de France aligns its strategy with a concrete and ambitious sustainable development policy. Its growth model is based on responsiveness to customers and constructive dialogue with its employees and partners. This document is the activity report of the group for the year 2006. It presents: 1 - the corporate profile of the group; 2 - its strategies (energy, energy supply, infrastructures); 3 - its financial highlights; 4 - its governance, shareholders and human resources; 5 - the activities of the group (exploration and production, energy procurement, energy sales, services, transmission France, storage France, LNG terminals, distribution France, transmission and distribution international, research and development); 6 - its 2006 financial data and financial summary

  18. Gaz de France and the sustainable development in 2005

    International Nuclear Information System (INIS)

    2006-01-01

    This booklet provides information on the Gaz de France group involvement in the sustainable development: the stakes, the approach, the energy challenge answers, the security and the solidarity and the active part in the territories development. (A.L.B.)

  19. Gaz de France annual report 2000; Gaz de France rapport annuel 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    A leader in the natural gas market in Europe, Gaz de France is an integrated group active in all sectors of the natural gas industry. In exploration and production, trading of natural gas, transmission, storage, distribution, energy management, air conditioning and heating, the Group has developed recognized skills and know-how both upstream and down to assure its customers of diversified, efficient and competitive services. A leader in liquefied natural gas, storage and distribution technologies, the Gaz de France Group has strong positions in Europe and operates throughout the world by promoting a strategy of alliances and partnerships at all levels of the gas industry. The goal of the Gaz de France Group is to continue to expand and develop its activities from the wellhead to the burner tip, and to seize, in France and throughout the world, the best opportunities offered to capitalize on its strengths. This activity report presents: the corporate profile, the financial highlights, the principal subsidiaries and affiliates, the major European trunk lines the responsive, customer-focused services (exploration-production, trading, transmission, distribution, services), the actions to ensure performance (productive research, comprehensive quality assurance, mobilized workforce ready for the opening of the markets)

  20. Gaz de France 2006 sustainable development report; Gaz de France 2006 rapport developpement durable

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    A major European energy utility, the Gaz de France Group produces, purchases, transports, distributes and sells natural gas, electricity and related services for its residential, corporate and local government customers. this report presents the actions implemented by the group to incorporate sustainable development into its strategy. From the point of view of risks and opportunities, the group analyzes what it takes to ensure development that respects people and the environment, and it implements them in all its business lines and management systems. Content: Gaz de France, portrait of a major energy utility, highlights of 2006, challenges and strategy (defining strategy and sustainable development policy, specific risks and opportunities, activities of the Gaz de France group: challenges, impact for stakeholders, transparency and independence in governing), ranking and implementing (defining sustainable development policy: reviewing priorities, meeting all the challenges, publicizing and defending positions, increasing awareness, overseeing and monitoring results), results of the 2004-2006 sustainable development action plan, dialogue and action with stakeholders, performance assessment, performance in response to challenges: energy challenges (guaranteeing regular supplies, controlling atmospheric emissions, promoting energy conservation, developing renewable energy), industrial challenges (ensuring health and safety, limiting the overall environmental impact of group activities), social responsibility challenges (advocating corporate social responsibility, promoting human rights and fighting corruption, encouraging commitment to solidarity, promoting regional development through local initiatives, reconciling acquisitions, procurement and sustainable development, ensuring transparency in natural gas rates, providing shareholders with quality information, promoting diversity, a source of enrichment, making working conditions a performance factor), indicators and

  1. Greenhouse effect gases inventory in France during the years 1990-1999; Inventaire des emissions de gaz a effet de serre en France au cours de la periode 1990-1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    The present report supplies emission data, for France and for the period 1990-1999, concerning all the substances involved in the increase in the greenhouse effect and covered under the United Nations' Framework Convention on Climate Change (UNFCCC). The substances are the six direct greenhouse gases covered by the Kyoto protocol: carbon dioxide (CO{sub 2}), methane (CH{sub 4}), nitrous oxide (N{sub 2}O), the two species of halogenous substances - hydro-fluorocarbons (HFCs) and per-fluorocarbons (PFCs), and sulphur hexafluoride (SF{sub 6}). Emissions of sulphur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), non methane volatile organic compounds (NMVOCs), and carbon monoxide (CO), gases which indirectly make a significant contribution to the greenhouse effect, are reported under the Convention. The emissions of the six gases that directly contribute to the greenhouse effect are expressed in terms of Global Warming Potential (GWP) which decreased by 2.1 % in 1999 compared to 1990. The emissions of the four gases that indirectly contribute to the greenhouse effect are moving towards decrease: this is by 17% for NO{sub x}, 23% as regards NMVOCs, 33% for CO and by 44% regarding SO{sub 2}. Out of the six greenhouse gases covered by the Kyoto Protocol, CO{sub 2} accounts for the largest share in total GWP emissions (70 %), followed by N{sub 2}O (16 %), CH{sub 4} (12 %), HFCs (0.99 %), SF{sub 6} (0.5 %), and PFCs (0.39 %). (author)

  2. Gaz de France and the sustainable development in 2005; Gaz de France et le developpement durable en 2005

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This booklet provides information on the Gaz de France group involvement in the sustainable development: the stakes, the approach, the energy challenge answers, the security and the solidarity and the active part in the territories development. (A.L.B.)

  3. Research on hydrogen by Gaz de France

    International Nuclear Information System (INIS)

    Donat, G.; Lecoanet, A.; Roncato, J.-P.

    1978-01-01

    With the increasing energy needs of mankind and the earth's necessarily limited resources of fuel, the time will come when the demand for hydrocarbons will exceed the world production capacity. This situation will subsequently get even worse because of the depletion of recoverable reserves. Massive recourse to nuclear and solar energy thus appears indispensable, and the use of hydrogen as a vector for such energies has been under consideration for several years, especially in France where petroleum resources are very limited. Gaz de France has been doing research on the mass production of hydrogen by the decomposition of water and has just come to rather pessimistic conclusions as to the competitiveness of thermochemical processes in comparison with electrolytic methods. However, the electrolysis of water offers interesting prospects providing its efficiency and economics can be improved. Furthermore research on the storage and transportation of hydrogen has already enabled some conclusions to be drawn in these fields where gaseous vectors have very encouraging possibilities [fr

  4. Gaz de France. 2006 reference document; Gaz de France. Document de reference 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This document was issued by Gaz de France, the French gas utility, at the occasion of the opening of the capital of the company. It is intended to shareholders and presents the relevant informations relative to the annual consolidated financial statements of the group according to IFRS and French standards for the year 2005 (selected financial information, business overview, liquidity and capital resources, profit forecasts or estimates, compensation and benefits, issuer assets etc..). It includes also some complementary information about the activities of the group, its estate property, plants and equipments, its R and D and patenting activities, its management and administration, its 2005 and 2006 contracts etc.. (J.S.)

  5. Contribution of Gaz de France offers to the environmental quality of buildings; Les offres de Gaz de France au service de la qualite environnementale des batiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Cegibat, the information-recommendation agency of Gaz de France for building engineering professionals, has organized this conference meeting to present the contributions of Gaz de France offers in the improvement of the environmental quality of residential and tertiary buildings: environmental quality in France and in Europe, Gaz de France and the 'high environmental quality' (HQE) approach, experience feedback: combined solar-gas systems, examples of realizations. (J.S.)

  6. Gaz de France 2006 annual report; Gaz de France 2006 rapport d'activite

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Gaz de France is major European energy utility, which produces, purchases, transports, distributes and sells natural gas, electricity and related services for its residential, corporate and local government customers. Its strategic focuses are to develop an ambitious marketing strategy, pursue a supply and procurement policy that guarantees the Group's competitiveness, confirm its position as a benchmark infrastructure manager, and speed up its profitable growth in Europe. Gaz de France aligns its strategy with a concrete and ambitious sustainable development policy. Its growth model is based on responsiveness to customers and constructive dialogue with its employees and partners. This document is the activity report of the group for the year 2006. It presents: 1 - the corporate profile of the group; 2 - its strategies (energy, energy supply, infrastructures); 3 - its financial highlights; 4 - its governance, shareholders and human resources; 5 - the activities of the group (exploration and production, energy procurement, energy sales, services, transmission France, storage France, LNG terminals, distribution France, transmission and distribution international, research and development); 6 - its 2006 financial data and financial summary.

  7. Gaz de France and market regulation

    International Nuclear Information System (INIS)

    Carriere, J.F.; Balard, Th.

    2004-01-01

    Following an overview of the specific features of the European gas sector (characterised by highly concentrated production and increasing levels of production outside Europe and over long distances), the article describes the lead up to the opening of the market place in France. Following the application of the first directive in 2000, Gaz de France has carried out various measures, the aim of which was to achieve immediate efficiency (with the organizational separation of the transport and trading divisions, the separation of activities from an accounting viewpoint and the publication of a transparent TPA tariff as opposed to a discriminatory one). This opening of the gas sector has seen the start of a gradual process based on this experience. In addition to these initial measures, the opening of the gas markets has been subject to a regulatory framework as from January 2003, and the task of regulating the French gas sector has been given to the CRE (Commission de regulation de l'electricite). Thanks to the ongoing dialogue initiated by the latter with all key players in the market, progress has been achieved in various fields related to regulation. Even if this process is not complete, the French example demonstrates that the combined actions of the regulator and the market operators working together in a constructive manner and in stages, makes it possible to successfully introduce a genuinely open market. (authors)

  8. Gaz de France: first half 2007 results

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Paris, 29 August 2007, Gaz de France Group presents its first half 2007 results (billion euros): Sales revenue 13.78 (-11% with respect to 2006), EBITDA 3.11 (-4.9%), Operating income 2.33 ( -8.7%), Net income Group share 1.51 (-11%), Net income Group share per share 1.53 euro (-11%). The half-year results are attributable primarily to three factors: - A very difficult environment with exceptionally mild climate conditions in the first half, impacting nearly all of the businesses, and unfavourable market conditions, reflected in particular in the low gas prices on the markets; - A tariff context which did not negatively impact the sales margins following a very difficult year 2006; - Good performance in international activities. Despite the environment, the Group is maintaining its financial target for 2007, as announced in March this year: 2007 will be a year of consolidation. EBITDA is expected to be in line with that of 2006. This target assumes average climate conditions during the second half 2007.

  9. Gaz de France: first half 2007 results

    International Nuclear Information System (INIS)

    2007-01-01

    Paris, 29 August 2007, Gaz de France Group presents its first half 2007 results (billion euros): Sales revenue 13.78 (-11% with respect to 2006), EBITDA 3.11 (-4.9%), Operating income 2.33 ( -8.7%), Net income Group share 1.51 (-11%), Net income Group share per share 1.53 euro (-11%). The half-year results are attributable primarily to three factors: - A very difficult environment with exceptionally mild climate conditions in the first half, impacting nearly all of the businesses, and unfavourable market conditions, reflected in particular in the low gas prices on the markets; - A tariff context which did not negatively impact the sales margins following a very difficult year 2006; - Good performance in international activities. Despite the environment, the Group is maintaining its financial target for 2007, as announced in March this year: 2007 will be a year of consolidation. EBITDA is expected to be in line with that of 2006. This target assumes average climate conditions during the second half 2007

  10. Natural Gas Storage Seismic Monitoring Suivi sismique des stockages de gaz naturel

    Directory of Open Access Journals (Sweden)

    Mari J.L.

    2011-02-01

    Full Text Available IFP Energies nouvelles, CGGVeritas and GDF Suez have conducted together, since 1980, a series of seismic monitoring experiments in order to detect and follow the movements of the gas plume in natural gas geologic storages. Surface and well seismic surveys were carried out at different stages of the storage life. Permanent receiver arrays have been set down in wells. Permanent sources have been designed. Sources and receivers have been used to follow continuously the storage cycle during several years, providing time measurement accuracy within a tenth of a millisecond. Gas intrusion into an aquifer leads to an increase in the arrival times of reflections beneath the storage reservoir and to a variation of the reflection amplitudes at top and bottom of the reservoirs. Progressive variations of the seismic parameters may be followed during the initial infill period. Further movements of the gas plume with the annual in/out cycles are more difficult to follow, because of the simultaneous presence of gas and water in the pores. Arrival time variations of some tenths of a millisecond may be detected and measured. Saturations, using accurate picking of the arrival times, can be estimated in favourable cases. Because of the higher density of carbon dioxide, when stored in a supercritical phase, sensitivity of the seismic parameters, velocity, density and acoustic impedance to saturation variations will be about twice smaller for CO2 storages than it is for methane. IFP Energies nouvelles, la CGGVeritas et GDF Suez ont mené ensemble, depuis 1980, de nombreuses expériences de monitoring sismique afin de détecter et de suivre les mouvements du gaz dans des stockages géologiques de gaz naturel. Des acquisitions ont été réalisées à différents stades de la vie du stockage tant en sismique de surface qu’en sismique de puits. Des antennes de récepteurs permanentes ont été construites et implantées dans des puits. Des sources permanentes ont

  11. Activities of Gaz de France Group

    International Nuclear Information System (INIS)

    Anon.

    2003-01-01

    The Board of Directors of Gaz de France approved the Group's consolidated accounts for 2004. In a more dynamic economic environment than in 2003, the Gaz de France Group reports enhanced results and has continued to pursue its growth in Europe. Increase in net sales driven by sustained growth in sales (+ 8.9%): In 2004, net sales rose 8.9% compared with the 2003 financial year to reach a total of euro 18,129 m. This strong increase in business activities was driven by sustained growth in sales volumes both in France and Europe. Total Group sales volumes amounted to 730 TWh (approximately 66 billion cubic metres), equal to growth of 10.3%. Natural gas sales volumes increased by approximately 10% in France, and are almost 18% higher in Europe, notably in the United Kingdom, Italy, Belgium and the Netherlands. The Group has pursued the profitable development of its activities outside France. As a result, international activities account for 29% of total sales in 2004, against 23% in 2003. The contribution made by international subsidiaries - particularly those specializing in exploration and production - grew by a very substantial 44.3% to reach a total of euro 502 m in 2004. Energy and Services Offering Branch: this core business line, which includes natural gas and oil exploration and production, energy trading and sales, and services associated with the supply of energy, boasts net sales of euro 16,498 m, equal to growth of 10.8% compared with 2003. Infrastructures Branch: this division, which groups together all activities related to the management of transmission and distribution infrastructures in both the French domestic and international markets, generated net sales of euro 6,794 m in 2004, virtually unchanged from the previous year. This situation is the result of higher sales generated by the distribution subsidiaries operating outside France (+9.2%) offset by a decline in the sales performance of the Transmission, Storage and Distribution in France

  12. EdF-Gaz de France. No merger without dismembering

    International Nuclear Information System (INIS)

    Lepetit, V.

    2007-01-01

    Gathering together the two historical French energy monopolies, Electricite de France (EdF) and Gaz de France (GdF), and warranting low electricity and gas prices is still an attractive idea for some political and syndicate representatives. However, such a merger would create a dominating position which is forbidden with respect to Brussels criteria. (J.S.)

  13. The results of Gaz de France in 1996

    International Nuclear Information System (INIS)

    Gadonneix, P.

    1997-01-01

    The principle results of the national company activity for 1996 have been presented by Mr Gadonneix, president of Gaz de France. These results will allow to face in the best economic conditions the realisation of the next contract which has to be signed with the government. Financial results, commercial results, supplies, transport and storage, distribution system, research and development are detailed. (N.C.)

  14. Optimal use of the Gaz de France underground gas storage facilities; Utilisation optimale des stockages souterrains de Gaz de France

    Energy Technology Data Exchange (ETDEWEB)

    Favret, F.; Rouyer, E.; Bayen, D.; Corgier, B. [Gaz de France (GDF), 75 - Paris (France)

    2000-07-01

    This paper describes the tools developed by Gaz de France to optimize the use of its whole set of underground gas storage facilities. After a short introduction about the context and the purposes, the methodology and the models are detailed. The operational results obtained during the last three years are presented, and some conclusions and perspectives are given. (authors)

  15. Spectral study of the luminescence produced by the excitation of noble gases by alpha-rays; Etude spectrale de la luminescence due a l'excitation des gaz rares par les rayons alpha

    Energy Technology Data Exchange (ETDEWEB)

    Koch, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Luminescence spectra of the noble gases He, A, Kr and Xe are studied under excitation by {alpha} rays. It is shown that the energy is transferred from excited levels of these gases to Hg and N{sub 2} impurities for impurity concentrations respectively less than 10{sup 6} and 10{sup 4}. These results confirm previous measurements concerning the period of luminescence and its variations versus nitrogen concentration in noble gases. (author) [French] On etudie les spectres de luminescence des gaz rares, He, A, Kr et Xe excites par une source intense de rayons {alpha}. Le transfert d'energie des etats excites des gaz rares sur les impuretes mercure et azote pour des concentrations respectives de ces impuretes inferieures a 1 ppm et 100 ppm est demontre. Ces resultats confirment les mesures anterieures concernant la duree de luminescence et ses variations avec la concentration d'azote dans les gaz rares. (auteur)

  16. The merging of Suez and 'Gaz de France'

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    The merging of 'Gaz de France' and Suez has been approved by the shareholders on the 16 july 2008, and the decree for the privatization of 'Gaz de France' has been published to the 'Journal Officiel'. The French state will hold 35.6% of the capital of the new group GDF-Suez. The board of directors will be composed of 24 members: 7 officials from the state, 1 representative of the share-holding staff, 3 representatives of the elected employees and 13 members named by the general assembly of the shareholders. This group, which is officially born on the 22. of july 2008, is the fourth bigger group worldwide in the domain of energy. (A.C.)

  17. Gaz Metropolitain's experience in regards to transmission access

    International Nuclear Information System (INIS)

    Noel, J.-P.

    1994-01-01

    The natural gas industry in Canada is briefly reviewed as it applies to the sale of transported gas in Quebec. The deregulation of the industry which occurred in 1985 brought many changes to the relationships among natural gas consumers, suppliers, transmission companies, and distribution utilities. It is noted that only the producers' natural gas sale price has been deregulated, not the rates of transmission companies or distributors. Deregulation offered two possibilities for natural gas users in Quebec: the client can contract a transmission service between the Alberta (source of supply) and Quebec borders, separately from contracting a delivery service from Gaz Metropolitain, the company supplying the vast majority of natural gas in Quebec; or the client can contract those two services from Gaz Metropolitain who then gathers the gas at the Alberta border. The adoption of Gaz Metropolitain services to meet the need for transmission access are discussed in the areas of supply contracts, and services offered (buy/sell, rate unbundling, delivery). The opportunities and risks for the customer are assessed in the areas of costs, speculation on transportation capacity, operational flexibility, and the possiblity of unused capacities. Opportunities and issues for the distributor include maintenance of client satisfaction, shortening of the duration of contracts, maintenance of the role of the distributor in natural gas sales, take-or-pay commitments, rate unbundling, accounting methods, inventories, and pricing

  18. Case-book of all decisions taken by the Regie du gaz naturel from April 1, 1995 - March 31, 1996

    International Nuclear Information System (INIS)

    Precourt, L.; L'Heureux, L.

    1996-01-01

    All decisions taken by the Regie du gaz naturel du Quebec during the period of April 1, 1995 to March 31, 1996 were presented. The case-book includes all legal decisions concerning the supply, transmission and storage of natural gas delivered or intended for delivery by pipeline distribution in the Province of Quebec. The text of the Act, amendments and revisions to the Act, and summaries of Board decisions are provided in French and English. Also included are a number of indexes for ease of reference and a glossary of relevant terms

  19. A contribution from Gaz de France to the economic performance of industries; Contribution de Gaz de France a la perfomance economique des industriels

    Energy Technology Data Exchange (ETDEWEB)

    Depail, J.C. [Gaz de France (GDF), 75 - Paris (France)

    1996-12-31

    The aim of the policy of the French national gas utility, Gaz de France, towards industries, is to promote natural gas as a competitive fuel compared to fuels and electric power, with energy efficient solutions that are easy to implement and maintain: space heating, paint curing, surface cleaning, bath heating, vapour generation, waste treatment (especially for molding sand and volatile organic compounds, sludge drying). Gaz de France proposes also expertise schemes and audits

  20. Mortal waiting for EdF and Gaz de France

    International Nuclear Information System (INIS)

    Jemain, A.

    2003-01-01

    Electricite de France (EdF) and Gaz de France (GdF) utilities have announced important investment programs for the forthcoming opening of gas and electricity markets to 2.5 millions of professionals by July 1, 2004. However, nothing can be done before the approval of the French government has been given for the change of their statuses (from the industrial and commercial public company status to the anonymous company status) and for the opening of their capital. Short paper. (J.S.)

  1. Gaz Metropolitain 2002 report : connecting with the future

    International Nuclear Information System (INIS)

    2003-01-01

    Gaz Metropolitain is the major natural gas distributor in Quebec. In 2002, the utility had its best year ever in terms of Partners' income of $154.6 million, representing a 9.5 per cent increase from 2001. Income from its core business, the distribution of natural gas in Quebec and Vermont, was $7.5 million higher than in 2001. This increase in income was due in part to better transportation and load balancing transactions. The main business effort in 2002 was on cogeneration plant projects developed with Boralex and Hydro Quebec. The projects, however, were not retained. This annual report presented consolidated financial and operating data for the distribution and transmission sectors of the company. It included information about Gaz Metropolitain's customers, the transmission and supply system, mission objectives, partnerships, corporate structure, and the year in review. The consolidated financial statements included income and cash flows, consolidated normalized volumes, and consolidated balance sheets. Revenue and expenditure statements were summarized by source. tabs., figs

  2. Petroleum labour market information supply demand analysis 2009-2020

    International Nuclear Information System (INIS)

    2010-03-01

    Since 2006, the petroleum industry has been interested in collaboration to determine labour demand and supply/demand gaps for the upstream petroleum industry. In 2006, the petroleum industry experienced strong employment growth and was having difficulty finding workers. Comprehensive, up-to-date labour market information and analysis are the key foundation for addressing labour supply/demand issues. This document presented labour market information on the petroleum industry in order to inform company retention and recruitment offices; government departments involved in development of labour market policies and programs; education and training institutions; guidance counsellors, employment centres and organizations that work with youth and labour supply pools; and job seekers. Specific topics that were discussed included two industry scenarios (growth and base case) in determining the petroleum industry's medium-and long-term employment needs; labour supply/demand considerations for the industry as a whole and an industry-wide cost management; and an analysis of exploration and production, oil sands, services, and pipeline sectors to 2020. It was concluded that while new employment is not expected to lead to labour shortages within the pipeline sector, attrition due to requirements almost certainly would. In the growth scenario, it is likely the pipeline sector will be challenged by competition from the other petroleum industry sectors. tabs., figs., appendices.

  3. Petroleum labour market information supply demand analysis 2009-2020

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-03-15

    Since 2006, the petroleum industry has been interested in collaboration to determine labour demand and supply/demand gaps for the upstream petroleum industry. In 2006, the petroleum industry experienced strong employment growth and was having difficulty finding workers. Comprehensive, up-to-date labour market information and analysis are the key foundation for addressing labour supply/demand issues. This document presented labour market information on the petroleum industry in order to inform company retention and recruitment offices; government departments involved in development of labour market policies and programs; education and training institutions; guidance counsellors, employment centres and organizations that work with youth and labour supply pools; and job seekers. Specific topics that were discussed included two industry scenarios (growth and base case) in determining the petroleum industry's medium-and long-term employment needs; labour supply/demand considerations for the industry as a whole and an industry-wide cost management; and an analysis of exploration and production, oil sands, services, and pipeline sectors to 2020. It was concluded that while new employment is not expected to lead to labour shortages within the pipeline sector, attrition due to requirements almost certainly would. In the growth scenario, it is likely the pipeline sector will be challenged by competition from the other petroleum industry sectors. tabs., figs., appendices.

  4. Le Gaz Naturel Véhicule Natural Gas for Vehicles

    Directory of Open Access Journals (Sweden)

    De Chauveron S.

    2006-11-01

    Full Text Available Cet article présente le GNV (Gaz Naturel Véhicule. Le GNV a en effet de sérieux atouts, à la fois comme carburant de substitution et comme carburant propre. Ces atouts sont aussi bien économiques que techniques. La première partie est consacrée aux enjeux du développement du GNV. Les premiers pays utilisateurs ont été ceux qui disposent sur leur sol de ressources de gaz naturel. Aujourd'hui, alors que de nombreux pays doivent faire face à l'inquiétude croissante relative à l'augmentation de la pollution urbaine, le gaz naturel apparaît également comme un carburant propre, permettant de réduire rapidement les émissions de polluants des véhicules. Dans une deuxième partie, nous donnons une description technique sommaire des stations GNV et des véhicules GNV. Il s'agit de familiariser le lecteur avec les quelques spécificités techniques du GNV, par rapport à l'essence et au gazole. On constatera d'ailleurs que les technologies GNV sont très proches des technologies classiques. Enfin, la dernière partie est consacrée aux actions en cours, qui permettront le développement du GNV en France et en Europe : programmes de recherche, réduction des coûts de la filière, actions réglementaires, communication, etc. This article presents compressed natural gas for vehicles (CNG, which can provide considerable advantages both as an alternative fuel and as a clean fuel. These assets are not only economic but also technical. The first part deals with what is at stake in developing natural gas as a motor fuel. The first countries to use CNG were those with natural gas resources in their subsoil. Today, with a large number of countries having to cope with growing concern about increasing urban pollution, natural gas is also seen as a clean fuel that can help cut vehicle pollutant emissions dramatically. In the second part a brief technical description is given of CNG stations and vehicles, with the aim of acquainting the reader with

  5. Cycle e-business: the e-business of Gaz De France; Cycle e-business: l'e-business de Gaz de France

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This paper deals with the Gaz De France Group position in the e-business context. In terms of e-business, all is done to put Internet at the marketing service. Three examples of Internet sites realization and the future policy are presented. (A.L.B.)

  6. Toprak Radon (222Rn Gazı Anomalilerinin ARIMA Analizi

    Directory of Open Access Journals (Sweden)

    Miraç KAMIŞLIOĞLU

    2014-12-01

    Full Text Available Özet: Zaman serileri analizi, istatistik, ekonomi, fizik ve mühendislik gibi bilim dallarında geniş uygulama alanına sahiptir. Zaman serisi analizi, değişkenlerin gelecekteki değerlerinin doğru bir şekilde tahmin edilmesi için kullanılan bir yöntemdir. Bu çalışmada, bir deprem öncüsü olarak bilinen toprak radon gazı (222Rn ölçümleri ile bir zaman serisi oluşturulmuştur. Bu veriler kullanılarak, otoregresif süreçler (ARIMA yardımıyla dinamik sistem modellemesi yapılmıştır. ARIMA; zaman serileri analizinde, zaman içerisinde rastgele gerçekleşen bir stokastik (olasılıksal sürecin veya hatalarının modellenmesidir. ARIMA modeli, temelde Box-Jenkins modeline dayanmaktadır. Box-Jenkins modeli, tek değişkenli zaman serilerinin ileriye dönük tahmin ve kontrolünde kullanılan istatistiksel tabanlı bir yöntemdir. Elde edilen sonuçlar, ARIMA modellerinin tahmin konusundaki başarısını göstermektedir. Anahtar kelimeler: Zaman Serileri Analizi, Radon Gazı (222Rn, ARIMA ARIMA Analysis of Soil Radon (222Rn Gas Anomalies Abstract: Time series analysis, has wide applications in statistics, economics, physics and engineering such disciplines. This method used for estimate correctly future values of the variables. In this study, is formed a time series with soil radon gas (222Rn measurements known as a pioneer of an earthquake. Dynamic system modelling was performed with autoregressive (ARIMA modelling process by used these measurements. ARIMA; time series analysis is modelled of the recoverable over time a random stochastic (probabilistic process or its errors. ARIMA model is based on Box-Jenkins model. Box-Jenkins model is a statistically based method which is used forward-looking forecasting and control of univariate time series. The obtained results, ARIMA model is indicating success in predict subject. Key words: Time Series Analysis, Radon Gas (222Rn, ARIMA

  7. Some results on the fluorescence of gases excited by high-energy charged particles; Quelques resultats concernant la fluorescence de gaz excites par des particules chargees de grande energie

    Energy Technology Data Exchange (ETDEWEB)

    Koch, L; Lesureur, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The essential characteristics of rare gases for use as scintillators are as follows: a very brief period of luminescence, generally less than 10{sup -8} s; a linear response as a function of the energy lost by the nuclear particle in the gas, even in the case of strongly ionising particles (fission fragments). In the gaseous or condensed state therefore, they are of great interest in nuclear physics. (author) [French] Les caracteristiques essentielles des gaz rares en tant que scintillateurs sont: une duree de luminescence tres breve, inferieure a 10{sup -8} s en general; une reponse lineaire en fonction de l'energie perdue par la particule nucleaire dans le gaz, meme dans le cas de particules fortement ionisantes (fragments de fission). A l'etat gazeux ou condense, ils presentent donc un grand interet en physique nucleaire. (auteur)

  8. Recent and future developments at the Regie du gaz naturel

    International Nuclear Information System (INIS)

    Giroux, J.

    1995-01-01

    The history of the Quebec Regie du gaz naturel, dating back to 1932, and its role in distributing natural gas in Quebec was described. Among more recent developments construction of a natural gas distribution system on the south shore of Quebec City was discussed. Unlinked mini-systems were built in St-Romuald and Levis. Gas was delivered by truck until an underwater crossing was completed. The federal-provincial infrastructures program was also summarized. The most important ruling by the Regie was the D-94-19 decision on GMi's supply policy and the concept of u mbrella buy-sell . Although this policy was originally approved by the Regie, after consideration of all factors, it was decided that this system was not in line with the deregulation trend and that buyers and sellers could do without GMi's intrusion in their contractual agreements. Issues to be addressed by the Regie in the coming months included transportation service, unbundling, cost allocation and rate of return adjustments mechanism in regards to the recent National Energy Board (NEB) decision on the subject, and separation of (LDC) distribution activities from LDC sales

  9. Natural gas and laundry: an efficient duo; Conference Cegibat: Gaz naturel et blanchisserie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Cegibat, the information-recommendation agency of Gaz de France for building engineering professionals, has organized this conference about the use of natural gas in the laundry sector. This document summarizes the content of the different talks dealing with: the history and evolution of laundry activity, the energy consumption problem, the gas appliances (dryers) and their advantages, some testimonies in the health sector (hospitals), the regulatory aspects, the economic aspects (tariffs), Gaz de France energy diagnostic offer, and the testimony of a launderette. (J.S.)

  10. Black and blue gas, the Gaz de France story during the last forty years

    International Nuclear Information System (INIS)

    Beltran, A.; Williot, J.P.

    1992-01-01

    This book narrates Gaz de France story during the last forty years. The author describes the great events such change from coal gas to methane (black and blue gas), building of a national distribution network, natural gas promoting, negotiating on great supply contracts, research programs. 61 refs., 12 figs., 29 photos

  11. Report of visiting Laboratoire de Physique des Gaz et des Plasmas, Universite Paris-Sud

    International Nuclear Information System (INIS)

    Ferreira, J.L.

    1991-03-01

    The activities carried out by identification mission to the Laboratoire de Physique des Gaz et des Plasmas (LPGP) of Paris-Sud University are related. The mission is part of the project of Study on Plasma wave and Plasma turbulence which is part of international agreement between CAPES and COFECUB in France. (M.C.K.)

  12. Globalization of the natural gas industry; La mondialisation de l`industrie du gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    Deyirmendjan, J. [Gaz de France (GDF), 75 - Paris (France)

    1997-05-01

    After presenting a panorama of the international gas industry, a description of changes affecting the world gas industry, and an analysis of how environment-related demands give gas an opportunity to become the leading source of energy in the 21. century, Mr Jacques Deyirmendjan, Senior Executive-Vice-President of Gaz de France, tells his interviewer how French industry and national companies are designing their strategies to respond effectively to these changes.

  13. Gaz de France and Ruhrgas have made commitments towards the European commission

    International Nuclear Information System (INIS)

    Anon.

    2004-01-01

    The European Commission's DG Competition has decided to close its investigation into the alleged refusal by the French and German gas companies Gaz de France and Ruhrgas to grant the Norwegian subsidiary of the US gas producer Marathon access to their gas networks. Both companies have offered commitments to improve third party access to their respective transport networks in order to allow customers in France and Germany to benefit more effectively from the opening of the gas markets to competition. (author)

  14. Oil and Gas Prospects in Egypt Recherches d'huile et de gaz en Égypte

    Directory of Open Access Journals (Sweden)

    El Ayouti M. K.

    2006-10-01

    Full Text Available Accumulations of oil were first known in Egypt since 1968, some ten years after the famous Drake well in Pennsylvania in August 1859. These oil accumulation were found as seepages in tunnels dug for extracting sulphur in the area of Gemsa on the West coast of the Gulf of Suez. Since that time exploration activites were conducted on and off throughout a long history of operations which witnessed the use of the latest developments in exploration tools and techniques. So far, the main oil province in Egypt is the Gulf of Suez Basin, where the bulk of oil reserve have been found. Other hydrocarbon provinces are the Nile Delta Basin, the Abu Gharadig Basin and the Alamein ridge, both in the Western Desert. Three important gas discoveries were made in the Nile Delta Basin two of which are offshore, in addition to other so for non commercial gas finds. In addition to the known oil and gas discoveries the exploration activities throughout that long period contributed volumenous geological and geophysical material and data which added appreciably to the geology of Egypt at large, and in particular to the petroleum geology of the country. The Gulf of Suez oil province displayed very favourable conditions for the generation and trapping of hydrocarbons in Miocene and Pre-Miocene pools though at the same time it displayed very complicated geological setting which renders the exploration work a difficult task. The Nile Delta Basin, on the otherhand, is a relatively very recently explored area. Accordingly, extensive exploration work is still needed in order to evaluate the hydrocarbon possibilities of that basin. So for, gas has been discovered at a number of locations in lower Pliocene-Miocene pools. Whether future work would prove that oil generation took place remains to be seen. The Western Desert did not yet display the required response with regards to the exploration work conducted till now. To date, only few small discoveries have been made with oil

  15. Synthesis Gas Purification Purification des gaz de synthèse

    Directory of Open Access Journals (Sweden)

    Chiche D.

    2013-10-01

    ce faire, une étape de gazéification convertit la charge carbonée en un gaz de synthèse (mélange de CO et H2, lequel, après ajustement du ratio H2/CO et élimination du CO2, subit ensuite la réaction de FischerTropsch. Les gaz de synthèse contiennent cependant de nombreuses impuretés qui nécessitent d’être éliminées afin d’éviter l’empoisonnement des catalyseurs Fischer-Tropsch. En raison de la grande variété de charges pouvant être mises en oeuvre, la composition des gaz de synthèse est susceptible de subir d’importantes variations, en particulier de part la nature des impuretés (éléments, spéciation présentes ainsi que leurs teneurs relatives. La composition des gaz de synthèse est également soumise à des spécifications extrêmement sévères en terme de pureté liées à l’importante sensibilité aux poisons des catalyseurs FT. Pour ces raisons, la purification des gaz de synthèse constitue un défi majeur pour le développement des procédés B-XTL. Dans cet article, nous présentons les principaux enjeux liés à la purification des gaz de synthèse. Les différents types d’impuretés pouvant être présentes dans les gaz de synthèse sont présentées. L’influence de la nature de la charge, des technologies de gazéification ainsi que des conditions opératoires associées sur la nature des impuretés et leurs teneurs relatives est discutée. Une attention particulière est portée au devenir des composés soufrés, azotés, des halogènes, métaux lourds et métaux de transition. Les principales technologies de purification des gaz de synthèse (adsorption, absorption, réactions catalytiques, etc. sont finalement décrites, ainsi que les défis associés.

  16. Together on the same planet. Gaz de France and sustainable development in 2006; Ensemble sur la meme planete. Gaz de France et le developpement durable en 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This document presents the sustainable development policy of Gaz de France group. It identifies the challenges the group has to face in order to control the environmental impact of the Group's activities (exploration, production, procurement, re-gasification, transmission, storage, distribution, marketing and shares, services). The approach used is based on a voluntary commitment of the Group to dialogue and share current challenges with all its stakeholders, and to imagine other roads to development. The initiatives consist in clean production practices, development of renewable energy sources, energy conservation, investment in research, safety improvement, solidarity with underprivileged people, respect of local environment and of codes of conduct, accompanying local economic development and development of clean transport systems. (J.S.)

  17. Together on the same planet. Gaz de France and sustainable development in 2006; Ensemble sur la meme planete. Gaz de France et le developpement durable en 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This document presents the sustainable development policy of Gaz de France group. It identifies the challenges the group has to face in order to control the environmental impact of the Group's activities (exploration, production, procurement, re-gasification, transmission, storage, distribution, marketing and shares, services). The approach used is based on a voluntary commitment of the Group to dialogue and share current challenges with all its stakeholders, and to imagine other roads to development. The initiatives consist in clean production practices, development of renewable energy sources, energy conservation, investment in research, safety improvement, solidarity with underprivileged people, respect of local environment and of codes of conduct, accompanying local economic development and development of clean transport systems. (J.S.)

  18. Compatibility problems of canning materials with carbon dioxide at high temperatures; Problemes de comptabilite des materiaux de gainage avec le gaz carbonique aux temperatures elevees

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R; Loriers, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    and iron-aluminium alloys should increase as a result of the research carried out with a view to improving their technological and mechanical properties. (authors) [French] L'adoption, en France, du gaz carbonique sous pression comme fluide caloporteur dans les reacteurs avances des filieres graphite-gaz et eau lourde-gaz, a impose la recherche de materiaux de gainage susceptibilite prendre la releve des alliages de magnesium. En effet, ces derniers deviennent inutilisables au dessus de 500 C environ, en raison de la proximite de leur point de fusion et de leurs proprietes mecaniques alors defaillantes, quoique leur compatibilite avec le gaz carbonique reste relativement bonne. Le beryllium, particulierement seduisant en raison de sa faible section de capture pour les neutrons thermiques, presente, entre autres, un inconvenient grave: son utilisation dans le gaz carbonique n'est possible, des 600 C, que si ce gaz est rigoureusement desseche, la pression partielle de vapeur d'eau etant le facteur determinant imposant une dessication d'autant plus poussee que la pression nominale est plus elevee. Dans le cas contraire, apres une courte periode d'incubation, l'oxydation s'accelere, conduisant a une corrosion intergranulaire rapidement destructrice. Neanmoins, les alliages beryllium-calcium ou beryllium-magnesium, a 0,5 pour cent environ d'element d'addition, permettent de surmonter cette difficulte; ils restent utilisables en presence de quelques centaines de vpm de vapeur d'eau jusqu'a 700 C au moins. Les problemes metallurgiques lies a la mise en oeuvre du beryllium ou de ses alliages ont cependant conduit a envisager provisoirement l'utilisation d'aciers inoxydables austenitiques. Ces materiaux sont intrinsequement tres resistants a l'oxydation; mais, comme ils ne peuvent etre employes qu'en faible epaisseur, etant donne leur section de capture importante, il y a lieu de choisir les nuances comparativement les moins oxydables. Au dessus de 600 C, les nuances

  19. New results concerning the behaviour of fission gases in in-pile UO{sub 2} at high temperatures; Resultats nouveaux sur le comportement des gaz de fission a haute temperature dans l'UO{sub 2} en pile

    Energy Technology Data Exchange (ETDEWEB)

    Soulhier, R; Schurenkamper, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The authors consider in the first part the various phenomena giving rise to the production of fission gases towards the exterior of nuclear fuels. The following aspects are dealt with: diffusion, for which is considered the influence of the predecessors of the radioactive gases, the fission recoil, atom expulsion along the fission paths and the evaporation. In the second part the authors present the results obtained on UO{sub 2} samples subjected to irradiation at temperatures of between 150 and 2000 deg C: - At low temperatures the variation of the amount produced as a function of the half-life of the isotopes studied shows that recoil is hot the only cause of gas production. - Above 1800 deg C, a weight loss by evaporation has been observed and the influence of this phenomenon on gas liberation has been studied; thus the fraction of {sup 135}Xe liberated at 2000 deg C by processes other than evaporation is of the order of 10 per cent. - The influence of the various mechanism on the overall effect as a function of temperature is discussed. (authors) [French] Dans une premiere partie, les auteurs etudient les differents phenomenes pouvant donner lieu au degagement des gaz de fission hors d'un combustible. Sont traites successivement: la diffusion, pour laquelle on discute l'influence des predecesseurs des gaz radioactifs, le recul de fission, l'expulsion des atomes le long des trajets de fission et l'evaporation. Dans une deuxieme partie ils exposent les resultats obtenus sur des echantillons d'UO{sub 2} portes sous irradiation a des temperatures comprises entre 150 deg C et 2000 deg C: - A basse temperature la variation de la quantite degagee suivant la periode des isotopes etudies montre que le recul n'est pas la seule cause du degagement des gaz. - Au-dessus de 1800 deg C on a note une perte de poids par evaporation et on a evalue l'influence de ce phenomene sur la liberation des gaz: ainsi la fraction du {sup 135}Xe liberee a 2000 deg C par d'autres processus

  20. 2006 annual results: Gaz de France announces record-high results and exceeds its objectives

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Paris, 13 March 2007 - In fiscal year 2006, Gaz de France had the best operational performance in its history. The Group confirms the strength of its business model, with sound Infrastructure business and sharp growth in Exploration - Production, Trading and Sales: - Net income, Group share: 2.3 billion euros; - EBITDA: 5.15 billion euros; - Dynamic dividend policy: 1.1 euro per share (+62%); - Investments at stepped-up pace: 4 billion euros (+38%); - Contribution of Group's international activities doubled in two years (39% of sales); - Many operational advances: strengthened operations, Exploration-Production, LNG Infrastructures and Electricity; - Major steps completed in merger project with Suez.

  1. 2006 annual results: Gaz de France announces record-high results and exceeds its objectives

    International Nuclear Information System (INIS)

    2007-01-01

    Paris, 13 March 2007 - In fiscal year 2006, Gaz de France had the best operational performance in its history. The Group confirms the strength of its business model, with sound Infrastructure business and sharp growth in Exploration - Production, Trading and Sales: - Net income, Group share: 2.3 billion euros; - EBITDA: 5.15 billion euros; - Dynamic dividend policy: 1.1 euro per share (+62%); - Investments at stepped-up pace: 4 billion euros (+38%); - Contribution of Group's international activities doubled in two years (39% of sales); - Many operational advances: strengthened operations, Exploration-Production, LNG Infrastructures and Electricity; - Major steps completed in merger project with Suez

  2. Energy of solution of rare gases in metals; Energie de dissolution des gaz rares dans les metaux

    Energy Technology Data Exchange (ETDEWEB)

    Blin, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In order to calculate the energy of solution of rare gases in metals, a method which has given good results in the case of solid solutions in metals has been applied. Nevertheless, it was necessary for this, to know the compressibility of gases under conditions which are not feasible in a laboratory. H. Jensen has studied this compressibility in a precise way for the rare gases Ar, Kr, Xe. It has thus been possible to calculate the energy of solution of these gases in different metals. These calculations have been carried out most thoroughly for the case of uranium. (author) [French] Nous avons applique au calcul de l'energie de dissolution des gaz rares dans les metaux, une methode qui a donne de bons resultats dans le cas des solutions solides metalliques. Il fallait pour cela connaitre la compressibilite des gaz rares dans des conditions impossibles a realiser en laboratoire. Cette compressibilite a ete etudiee par H. Jensen de facon precise pour les gaz rares A, Kr, Xe. Nous avons pu, de ce fait, calculer les energies de dissolution de ces gaz dans les differents metaux. Les calculs ont ete faits plus completement dans le cas de l'uranium. (auteur)

  3. Energy of solution of rare gases in metals; Energie de dissolution des gaz rares dans les metaux

    Energy Technology Data Exchange (ETDEWEB)

    Blin, J. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In order to calculate the energy of solution of rare gases in metals, a method which has given good results in the case of solid solutions in metals has been applied. Nevertheless, it was necessary for this, to know the compressibility of gases under conditions which are not feasible in a laboratory. H. Jensen has studied this compressibility in a precise way for the rare gases Ar, Kr, Xe. It has thus been possible to calculate the energy of solution of these gases in different metals. These calculations have been carried out most thoroughly for the case of uranium. (author) [French] Nous avons applique au calcul de l'energie de dissolution des gaz rares dans les metaux, une methode qui a donne de bons resultats dans le cas des solutions solides metalliques. Il fallait pour cela connaitre la compressibilite des gaz rares dans des conditions impossibles a realiser en laboratoire. Cette compressibilite a ete etudiee par H. Jensen de facon precise pour les gaz rares A, Kr, Xe. Nous avons pu, de ce fait, calculer les energies de dissolution de ces gaz dans les differents metaux. Les calculs ont ete faits plus completement dans le cas de l'uranium. (auteur)

  4. Annual report on theoretical work of the S.T.G.I. (Section de theorie des gaz ionises)

    International Nuclear Information System (INIS)

    1984-01-01

    This report presents in a detailed form the theoretical work of the STGI (Section Theorie des Gaz Ionises). It is thus hoped that the present report will be useful for physicists interested in additional information. Works an plasma equilibrium and its evolution are shortly presented together with works on plasma heating and current drive. Kinetic theory and spectroscopy are not forgotten

  5. Graphite suspension in carbon dioxide; Suspension de graphite dans le gaz carbonique

    Energy Technology Data Exchange (ETDEWEB)

    Roche, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Moussez, C; Rouvillois, X; Brevet, R [Societe Nationale d' Etude et de Construction de Moteurs d' Aviation (SNECMA), 75 - Paris (France)

    1965-07-01

    Since 1963 the Atomic Division of SNECMA has been conducting, under a contract with the CEA, an experimental work with a two-component fluid comprised of carbon dioxide and small graphite particles. The primary purpose was the determination of basic engineering information pertaining to the stability and the flowability of the suspension. The final form of the experimental loop consists mainly of the following items: a light-phase compressor, a heavy-phase pump, an electrical-resistance type heater section, a cooling heat exchanger, a hairpin loop, a transparent test section and a separator. During the course of the testing, it was observed that the fluid could be circulated quite easily in a broad range of variation of the suspension density and velocity - density from 30 to 170 kg/m{sup 3} and velocity from 2 to 24 m/s. The system could be restarted and circulation maintained without any difficulty, even with the heavy-phase pump alone. The graphite did not have a tendency to pack or agglomerate during operation. No graphite deposition was observed on the wall of the tubing. A long period run (250 hours) has shown the evolution of the particle dimensions. Starting with graphite of surface area around 20 m{sup 2}/g (graphite particles about 1 {mu}), the powder surface area reaches an asymptotic value of 300 m{sup 2}/g (all the particles less than 0.3 {mu}). Moisture effect on flow stability, flow distribution between two parallel channels, pressure drop in straight tubes, recompression ratio in diffusers were also investigated. (author) [French] Depuis 1963 la Division Atomique de la SNECMA conduit, dans le cadre d'un contrat avec le Commissariat A l'Energie Atomique, l'etude experimentale d'une suspension de fines particules de graphite dans le gaz carbonique. L'objectif principal est d'obtenir des informations d'ordre mecanique et technologique sur la mise en oeuvre de l'ecoulement de ce fluide diphase. Le circuit experimental comprend principalement: un

  6. Evolution dans la gestion de la détection gaz

    CERN Document Server

    Bonthond, F

    1999-01-01

    Cet article présente l'interface graphique qui a été développée pour gérer d'une façon visuelle et globale la détection des gaz inflammables utilisés dans les expériences du hall EHN1 (NA49, NA56, tests pour ATLAS, CMS, Alice, etc.). A cet effet, on utilise des détecteurs catalytiques connectés à une centrale. Afin de retransmettre les alarmes à la salle de contrôle des pompiers, cette centrale est couplée à un automate programmable connecté au réseau Ethernet du CERN. Une liaison filaire entre l'automate et le synoptique câblé des alarmes de niveau 3 assure la redondance nécessaire à ce type d'alarmes. Le logiciel de contrôle LabView a été utilisé pour développer l'interface graphique. Elle permet de visualiser sur n'importe quel PC ou X-Terminal le taux de remplissage des bouteilles de gaz, la position des électrovannes ainsi que les asservissements qui pilotent lors d'une alarme, notamment les ventilations, les panneaux de signalisation et les arrêts d'urgence.

  7. Replacing Sugar by Date Syrup in Gaz and Investigation of Texture Properties

    Directory of Open Access Journals (Sweden)

    Fateme Raiesi Ardali

    2013-10-01

    Full Text Available Date Syrup is a natural sweetener that is suitable replacement for sugar in food stuffs formulation. In this Research Amounts of 25-100 percent of sugar in Gaz formulation were replaced with date syrup and to study effect of its use in product formulation, characteristics of texture, color and sensory analyse of treatments were investigated. Statistical analyse of data was also done by SPSS software and Dankan test. The results of this research showed that amount of used date syrup in formulation had a significant effect on  color parameters  (L*,a*,b*, texture characteristics and sensory analyse of samples. By increase of date syrup in Gaz formulation, samples texture became softer than control sample and yellowness and redness index of samples were increasedDoi: DOI: 10.12777/ijse.6.1.11-15 [How to cite this article:  Shafiei, Z., Hojjatoleslami, M.,  Soha, S., and Shariati, M.A. 2014. The Influence of Malt Extraction Adding to UF Fresh Low Fat Cheese on Its Textural Properties. International Journal of Science and Engineering, 6(1:57-60. Doi: 10.12777/ijse.6.1.11-15

  8. Natural gas cogeneration in the residential sector; La cogeneration au gaz naturel en residentiel

    Energy Technology Data Exchange (ETDEWEB)

    Lancelot, C.; Gaudin, S. [Gaz de France, GDF, Dir. de la Recherche, 75 - Paris (France)

    2000-07-01

    The natural gas cogeneration offer is now available and operational in the industrial sector. It is based on technologies of piston engines and gas turbines. Currently, this offer is sufficiently diversified, so much from the point of view of the range of powers available (from 1 MW to more than 40 MW electric) that number of manufacturers. In order to widen the cogeneration market in France to the markets of the commercial and residential sectors, Gaz De France has undertaken a technical economic study to validate the potential of those markets. This study led to work on the assembly of a french die to cogeneration packages of low power (less than 1 MW electric). This step has emerged at the beginning of 1999 with the launching of a commercial offer of cogeneration packages. In margin to this work Gaz De France Research division also initiated a study in order to evaluate the offer of micro cogeneration, products delivering an electric output lower than 10 kW. (authors)

  9. The take-over of Gaz Metropolitain by Hydro-Quebec

    International Nuclear Information System (INIS)

    Bernard, J-T.

    1997-01-01

    The implications of a take-over of Gaz Metropolitain by Hydro-Quebec in early 1997 and the pricing of electricity and natural gas in Quebec were discussed. In January 1997, Hydro-Quebec purchased all the shares in Noverco that were formerly owned by SOQUIP. With this purchase, Hydro-Quebec became the major share holder in Noverco, the company that controls Gaz Metropolitain. This type of take-over, where an electrical utility purchases the interests in a natural gas distributor, has also been observed in the United States and is believed to be a consequence of the recent deregulation of the electricity market. In the near future, it is believed that consumers will probably pay for equivalent energy use (like heating or cooling) rather than separate tariffs for electricity or natural gas consumption. The recent popularity of gas-fueled electrical cogenerating stations is also believed to be an important factor in this take-over. 1 ref., 3 tabs

  10. Les perspectives du gaz naturel dans le Monde World Natural Gas Prospects

    Directory of Open Access Journals (Sweden)

    Valais M.

    2006-11-01

    Full Text Available Dans un monde en quête de diversification énergétique, le gaz naturel apparaît comme une source d'énergie particulièrement attrayante. Par son abondance, sa facilité de substitution aux produits pétroliers dans une gamme très large d'usages, il pourrait assurément jouer un rôle beaucoup plus important dans la couverture des besoins énergétiques mondiaux. Toutefois, de nombreux obstacles semblent devoir ralentir sa progression. Cet article dégage les grands paramètres techniques et économiques qui devraient conditionner le développement de l'industrie du gaz dans le monde et présente des perspectives d'évolution de sa production et de son commerce international d'ici à la fin du siècle. For a world in search of energy diversification, natural gas is a particularly attractive source. Its abundance and its facility for being substituted for petroleum products over a wide range of uses should certainly mean that it will play a much more important rote in filling world energy needs. Nonetheless, many obstacles are hindering its progress. This article outlines the leading technical and economic parameters which should influence the development of the world gas industry, and the prospects for its production and international trade evolution between now and the end of the century.

  11. The performance of the natural gas solutions in the accommodation; La performance des solutions gaz naturel dans l'habitat

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This paper presents the Gaz De France Group policy concerning the utilization of the gas as energy source in residential buildings for heating and cooking. The market and more specially the manufacturers importance are discussed. (A.L.B.)

  12. Les recherches menées par le Gaz de France dans le domaine de l'hydrogène Research on Hydrogen by Gaz de France

    Directory of Open Access Journals (Sweden)

    Donat G.

    2006-11-01

    Full Text Available Les besoins en énergie de l'humanité allant croissant et les ressources en combustibles de la Terre étant obligatoirement limitées, le temps viendra où la demande en hydrocarbures excédera la capacité mondiale de production; cette situation s'aggravera encore ultérieurement du fait de l'épuisement des réserves récupérables. Un recours massif aux énergies nucléaire et solaire semble donc indispensable et l'utilisation de l'hydrogène comme vecteur de ces énergies retient depuis quelques années l'attention, notamment en France où les ressources propres en pétrole sont faibles. Le Gaz de France a entrepris des recherches sur la production massive de l'hydrogène par décomposition de l'eau et vient de parvenir à des conclusions pessimistes quant à la compétitivité, par rapport à la voie électrolytique, de la filière utilisant des cycles thermochimiques. Par contre, l'électrolyse de l'eau offre des perspectives intéressantes à condition d'améliorer ses performances et son économie. D'autre part, des études concernant le stockage et le transport de l'hydrogène ont permis d'ores et déjà de tirer quelques conclusions dans ces domaines où les vecteurs gazeux disposent d'excellents atouts. With the increasing energy needs of mankind and the earth's necessarily limited resources of fuel, the time will come when the demand for hydrocarbons will exceed the world production capacity. This situation will subsequently get even worse becouse of the depletion of recoverable reserves. Massive recourse ta nuclear and solar energy thus appears indispensable, and the use of hydrogen as a vector for such energies has been under consideration for several years, especially in France where petroleum resources are very limited. Gaz de France has been doing research on the mass production of hydrogen by the decomposition of water and has just come ta rather pessimistic conclusions as ta the competitiveness of thermochemical processes in

  13. The reactions of magnesium and its alloys with moist gases at high temperatures; Les reactions du magnesium et de ses alliages avec les gaz humides aux temperatures elevees

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-02-15

    The kinetics and mechanisms of the reaction of pure or low alloyed magnesium with various gas saturated by water vapor: oxygen, argon, nitrogen, air, carbon dioxide, have been studied and compared in the temperature range 350-600 deg C. After picturing the large chemical reactivity of magnesium surface, the more or less properties of the oxide film, always made of magnesia, have been shown depending on the nature of the gas carrying water vapor; in fact, metal sublimation occurs the more easily as the surrounding atmosphere is less oxidizing. Moreover, an activation energy change is systematic, but at a temperature which depends also on the latter. In the case of the alloys, the linear oxidation rate is generally obtained only after short induction periods, parabolic in nature. Two possibilities of corrosion inhibition of magnesium by water vapor are then demonstrated and explained: either by a partial superficial fluoridation, or when the carrier gas is carbon dioxide. Also, the extreme conditions of oxidation were studied, that is the ignition processes that occur at a particular temperature in every gas mixture. Finally, it is tried to evolve the fundamental and practical significance of all the results. (author) [French] On a etudie et compare par voie thermogravimetrique, micrographique et radiocristallographique, les cinetiques et les mecanismes de reaction du magnesium et de certains de ses alliages avec diverses atmospheres saturees en vapeur d'eau: oxygene, argon, azote, air, gaz carbonique, dans un domaine de temperatures s'etendant de 350 a 600 deg C, Apres avoir illustre l'extreme sensibilite chimique de la surface du magnesium, on a tout d'abord montre que la valeur plus ou moins protectrice de la couche d'oxyde formee, pourtant toujours constituee de magnesie normale, depend de la nature du gaz porteur de la vapeur d'eau; en effet, la sublimation du metal intervient d'autant plus facilement que les atmospheres en presence sont moins oxydantes. De plus

  14. Together on the same planet. Gaz de France and sustainable development in 2006

    International Nuclear Information System (INIS)

    2006-01-01

    This document presents the sustainable development policy of Gaz de France group. It identifies the challenges the group has to face in order to control the environmental impact of the Group's activities (exploration, production, procurement, re-gasification, transmission, storage, distribution, marketing and shares, services). The approach used is based on a voluntary commitment of the Group to dialogue and share current challenges with all its stakeholders, and to imagine other roads to development. The initiatives consist in clean production practices, development of renewable energy sources, energy conservation, investment in research, safety improvement, solidarity with underprivileged people, respect of local environment and of codes of conduct, accompanying local economic development and development of clean transport systems. (J.S.)

  15. Fusion special: E.ON/Ruhrgas, EDF/Gaz de France? Trends. Interview. Inquiry. Portrait

    International Nuclear Information System (INIS)

    Schneid, O.; Carbier, M.Ch.

    2003-01-01

    This issue of 'Energies news' newsletter comprises 6 articles dealing with: the E.ON/Ruhrgas fusion and the birth of a leader of the gas-electric power convergence in Europe (the serial story of the fusion, the compromise with the adverse parties); the key economical data of RWE; the proposal of fusion between EdF (Electricite de France) and Gaz de France (interview of M. Boiteux, honorary president of EdF); the reorganization of RWE activities in France (interview of R. Felgentreff, head of RWE Solutions France); travel inside the French power market (part.2: opening of the power market to all professionals); portrait of J. Masdeu-Arus, co-president of a study group at the French house of commons, who made a report about the economical and financial situation of EdF. (J.S.)

  16. Cell for studying electron-adsorbed gas interactions; Cellule d'etudes des interactions electron-gaz adsorbe

    Energy Technology Data Exchange (ETDEWEB)

    Golowacz, H; Degras, D A [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires, Deptartement de Physique des Plasmas et de la Fusion Controlee, Service de Physique Appliquee, Service de Physique des Interractions Electroniques, Section d' Etude des Interactions Gaz-Solides

    1967-07-01

    The geometry and the technology of a cell used for investigations on electron-adsorbed gas interactions are described. The resonance frequencies of the surface ions which are created by the electron impact on the adsorbed gas are predicted by simplified calculations. The experimental data relative to carbon monoxide and neon are in good agreement with these predictions. (authors) [French] Les caracteristiques geometriques et technologiques generales d'une cellule d'etude des interactions entre un faisceau d'electrons et un gaz adsorbe sont donnees. Un calcul simplifie permet de prevoir les frequences de resonance des ions de surface crees par l'impact des electrons sur le gaz adsorbe. Les donnees experimentales sur l'oxyde de carbone et le neon confirment les previsions du calcul. (auteurs)

  17. New combustion, environment regulations: the answers for natural gas; Nouvelles reglementations, combustion, environnement: les reponses pour le gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    Le Peltier-Marc, A. [Gaz de France (GDF), 75 - Paris (France)

    1997-12-31

    This paper reports on the point of view from Gaz de France (GdF) company concerning the potential consequences of the use of natural gas in combustion systems with respect to the new regulations about combustion and environment. Details concerning the measures relative to the limitation of pollutants in small combustion installations (2 - 20 MW) are given (chimney height, SO{sub x}, NO{sub x} and dusts content in exhaust gases). (J.S.)

  18. Behaviour of rare gases in solids at high temperature; Comportement des gaz rares dans les solides a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Blin, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    In this article a number of simple results regarding the solubility and displacement of rare gases in solids have been assembled. These results were obtained from elementary considerations on highly compressed gases and on dislocations. They provide a better understanding of the now fairly numerous experiments dealing with the swelling of irradiated fuels, this swelling being due to the presence of a high proportion of gases in the fission products. Finally, the chances of success of the various methods which may be devised to diminish the swelling are examined. (author) [French] Nous avons rassemble dans ce texte un certain nombre de resultats simples relatifs a la solubilite et au deplacement des gaz rares dans les solides. Ces resultats ont ete obtenus par des considerations elementaires sur les gaz tres comprimes et sur les dislocations. Ils permettent de mieux comprendre les experiences, maintenant assez nombreuses, qui ont trait au gonflement des combustibles irradies; gonflement qui est du a la presence d'une forte proportion de gaz dans les produits de fission. On examine finalement les chances de succes des differents moyens que l'on peut imaginer pour attenuer le gonflement. (auteur)

  19. Contribution to the chromatography of atmospheric gases (1963); Contribution a la chromatographie des gaz de l'air (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Ghalamsiah, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-06-15

    In the first part, the author studies the gas-phase chromatographic separation of the atmospheric rare gases, of hydrogen, and of some gaseous compounds of carbon (CO, CO{sub 2}, CH{sub 4}) using inactive gases to obtain the most favourable operational conditions far this separation. In the second part, the optimum conditions for detecting non-active gases using an ionisation chamber and a {sup 239}Pu radioactive source emitting 5.15 MeV {alpha} particles are determined. (author) [French] Dans une premiere partie, l'auteur etudie la separation par chromatographie en phase gazeuse des gaz rares de l'air, de l'hydrogene, et de quelques composes gazeux du carbone (CO, CO{sub 2}, CH{sub 4}) en utilisant des gaz inactifs an vue d'obtenir les conditions experimenales les plus favorables en vue de cette separation. Dans une deuxieme partie, les conditions optimales de detection de gaz non actifs a l'aide d'une chambre d'ionisation, en utilisant comme source radioactive du {sup 239}Pu qui emet des particules {alpha} de 5,15 MeV, sont determinees. (auteur)

  20. Measurement, with steady pressure rise, of the permeability of a gas through a porous membrane; Mesure, en montee continue de pression, de la permeabilite d'un gaz a travers une membrane poreuse

    Energy Technology Data Exchange (ETDEWEB)

    Davion, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    This study concerns a device for following the variations in the permeability of a gas across a porous membrane as a function of the average pressure, increasing steadily, which is applied to the membrane: P-bar; from these variations is deduced a value of an equivalent pore radius. A constant gas flow is introduced into an enclosure separated into two compartments by the membrane; the simultaneous variations of the pressure in the enclosure and of the pressure difference {delta} P between the two compartments are followed. After a transient period, {delta} P is given by an asymptotic expansion as a function of a dimensionless variable, w, whose expression includes several parameters (ratio of the compartment volumes, physical properties of the gas, pore radius, value of {delta} P in the steady state) and the variable pressure P. When w is large compared to unity, condition which gives an upper limit to the flow for a given membrane, the expansion is practically equal to its first term; the changes in {delta} P and in the permeability are then inversely proportional. The perturbing influences of various secondary effects (e. g. changes in the enclosure temperature) on the pore radius measurement have been estimated. (author) [French] Cette etude concerne un dispositif permettant de suivre les variations de permeabilite d'un gaz a travers une membrane poreuse en fonction de la pression moyenne, continument croissante, appliquee a cette membrane: P-bar; de ces variations se deduit la valeur d'un rayon de pore equivalent. Un debit de gaz constant est introduit dans une enceinte separee par la membrane en deux compartiments, et l'on suit les variations simultanees de la pression dans l'enceinte et de la difference de pression entre ces compartiments, {delta} P. A l'issue d'un stade transitoire, {delta}P est donne par un developpement asymptotique en fonction d'une variable sans dimensions, w, dont l'expression groupe plusieurs parametres (rapport des volumes des

  1. Study of gases contained in an Antarctica glacier; Etude des gaz contenus dans un glacier antarctique

    Energy Technology Data Exchange (ETDEWEB)

    Raynaud, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-15

    This report presents a study of gases contained in ice samples taken from a drilling 97.8 meters deep in the coastal zone of Adelie Land (Antarctica). Simultaneously, a study has been made of the composition of the atmospheric air and of the gases extracted in situ from the firn. Carbon dioxyde was analysed by means of gas-phase chromatography and argon, oxygen and nitrogen by means of mass spectrometry. The results obtained show that for the most part the oxygen concentration decreases with an increase in the depth of the drilling. The values range from a maximum of 20,83 per cent of the volume at the surface to a minimum of 19,46 per cent of the volume at a depth of 87 meters. The results also show that the distribution of carbon dioxide concentration does not vary with the depth. These concentrations are either in the same range as or lower than the concentration of CO{sub 2} found in atmospheric air. The different results are discussed. (author) [French] Le present travail rend compte d'analyses de gaz contenus dans des echantillons de glace provenant d'un forage de 97,8 m de profondeur, realise dans la zone cotiere de la Terre Adelie (Antarctique). Parallelement, la composition d'air atmospherique et de gaz extraits in situ du neve a ete etudiee. La chromatographie en phase gazeuse a ete utilisee pour analyser le CO{sub 2} et la spectrometrie de masse pour analyser l'argon, l'oxygene et l'azote. Les resultats obtenus indiquent essentiellement le long du forage: - une decroissance de la teneur en oxygene avec la profondeur, les valeurs extremes etant de 20.83 pour cent en volume a la surface et de 19,46 pour cent en volume a - 87 metres, - une repartition des teneurs en CO{sub 2} sans correlation nette avec la profondeur, ces teneurs etant de l'ordre ou inferieures a la teneur atmospherique. Les differents resultats sont discutes. (auteur)

  2. Contribution to the study of the ionization and heating of gases by laser radiation; Contribution a l'etude de l'ionisation et du chauffage des gaz par le rayonnement d'un laser declenche

    Energy Technology Data Exchange (ETDEWEB)

    Veyrie, P [Commissariat a l' Energie Atomique, Limeil-Brevannes (France). Centre d' Etudes

    1968-01-01

    The ionization and heating of gases by the concentrated radiation of a neodymium laser is studied. The power is 300 MW, the gas studied is primarily deuterium between 300 mm and 2280 mm. The first part concerns a certain number of experimental results on the absorption of the radiation and on changes produced in the plasma as a function of time. From these results are deduced a certain number of consequences, amongst which may be mentioned the definition of a pre-ionization threshold. These experimental results are interpreted in the second part. A calculation is made of the length of the period during which the electrons multiply up to when the absorption becomes measurable. The last phase corresponds to the hydrodynamics evolution, the calculations are compared with the experiments. The agreement between theory and experiment is satisfactory for the different phases. (author) [French] On etudie l'ionisation et le chauffage des gaz par le rayonnement concentre d'un laser au neodyme. La puissance est de 300 MW, le gaz etudie est principalement le deuterium entre 300 mm et 2280 mm. La premiere partie concerne un certain nombre de resultats experimentaux. Il s'agit de l'absorption du rayonnement et de l'evolution chronologique du plasma. De ces resultats on deduit un certain nombre de consequences parmi lesquelles il faut citer la definition d'un seuil de preionisation. Ces resultats experimentaux sont interpretes dans la deuxieme partie. On calcule la duree de la phase pendant laquelle se multiplient les electrons jusqu'a ce que l'absorption soit mesurable. La derniere phase correspond a l'evolution hydrodynamique. Les calculs sont confrontes avec l'experience. L'accord entre theorie et experience est satisfaisant pour les differentes phases. (auteur)

  3. Contribution to the study of the ionization and heating of gases by laser radiation; Contribution a l'etude de l'ionisation et du chauffage des gaz par le rayonnement d'un laser declenche

    Energy Technology Data Exchange (ETDEWEB)

    Veyrie, P. [Commissariat a l' Energie Atomique, Limeil-Brevannes (France). Centre d' Etudes

    1968-01-01

    The ionization and heating of gases by the concentrated radiation of a neodymium laser is studied. The power is 300 MW, the gas studied is primarily deuterium between 300 mm and 2280 mm. The first part concerns a certain number of experimental results on the absorption of the radiation and on changes produced in the plasma as a function of time. From these results are deduced a certain number of consequences, amongst which may be mentioned the definition of a pre-ionization threshold. These experimental results are interpreted in the second part. A calculation is made of the length of the period during which the electrons multiply up to when the absorption becomes measurable. The last phase corresponds to the hydrodynamics evolution, the calculations are compared with the experiments. The agreement between theory and experiment is satisfactory for the different phases. (author) [French] On etudie l'ionisation et le chauffage des gaz par le rayonnement concentre d'un laser au neodyme. La puissance est de 300 MW, le gaz etudie est principalement le deuterium entre 300 mm et 2280 mm. La premiere partie concerne un certain nombre de resultats experimentaux. Il s'agit de l'absorption du rayonnement et de l'evolution chronologique du plasma. De ces resultats on deduit un certain nombre de consequences parmi lesquelles il faut citer la definition d'un seuil de preionisation. Ces resultats experimentaux sont interpretes dans la deuxieme partie. On calcule la duree de la phase pendant laquelle se multiplient les electrons jusqu'a ce que l'absorption soit mesurable. La derniere phase correspond a l'evolution hydrodynamique. Les calculs sont confrontes avec l'experience. L'accord entre theorie et experience est satisfaisant pour les differentes phases. (auteur)

  4. Oxidation of steel heated in CO{sub 2} medium under pressure; Oxydation d'un acier ordinaire chauffe dans le gaz carbonique sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R.; Leclercq, D.; Bunard, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Behaviour of low-alloyed steels heated in CO{sub 2} medium under pressure is reported. Tests are carried out in the range of erature reached in the CO{sub 2} cooled reactors (vessel, thermal shield, pipes). The observed weight increases are small, even after more than a thousand hours of heating at 350 deg. C, but oxidation curve looks like progressing linearly. Furthermore, the oxide formed under a pressure of 15 kg/cm{sup 2} is undoubtedly more compact and adherent than the one formed under a pressure of 1 kg/cm{sup 2}. Finally, for practical use, CO{sub 2} steel pipes surface has to be sand blast and pickled. A following phosphatizing protects it from atmospheric corrosion during assembling, but these treatments have no influence on the behaviour of these steels heated in CO{sub 2}. (author)Fren. [French] On etudie le comportement d'aciers au carbone faiblement allies, chauffes dans le gaz carbonique sous pression, aux temperatures atteintes dans les reacteurs refroidis par ce gaz (caisson, bouclier thermique, canalisations). Les augmentations de poids observees sont faibles, meme apres plus de 1000 heures de chauffage a 350 deg. C, mais l'oxydation semble se poursuivre lineairement. De plus, l'oxyde forme dans le gaz carbonique sous pression de 15 kg/cm{sup 2} est nettement plus compact et adherent que celui forme sous pression atmospherique de gaz carbonique. Enfin, dans la pratique, les surfaces d'acier du circuit de gaz carbonique sont necessairement sablees ou decapees; une phosphatation ulterieure le protege de la corrosion atmospherique pendant le montage. Ces traitements sont sans influence sur le comportement de ces aciers dans le gaz carbonique a chaud. (auteur)

  5. Oxidation of steel heated in CO{sub 2} medium under pressure; Oxydation d'un acier ordinaire chauffe dans le gaz carbonique sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R; Leclercq, D; Bunard, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Behaviour of low-alloyed steels heated in CO{sub 2} medium under pressure is reported. Tests are carried out in the range of erature reached in the CO{sub 2} cooled reactors (vessel, thermal shield, pipes). The observed weight increases are small, even after more than a thousand hours of heating at 350 deg. C, but oxidation curve looks like progressing linearly. Furthermore, the oxide formed under a pressure of 15 kg/cm{sup 2} is undoubtedly more compact and adherent than the one formed under a pressure of 1 kg/cm{sup 2}. Finally, for practical use, CO{sub 2} steel pipes surface has to be sand blast and pickled. A following phosphatizing protects it from atmospheric corrosion during assembling, but these treatments have no influence on the behaviour of these steels heated in CO{sub 2}. (author)Fren. [French] On etudie le comportement d'aciers au carbone faiblement allies, chauffes dans le gaz carbonique sous pression, aux temperatures atteintes dans les reacteurs refroidis par ce gaz (caisson, bouclier thermique, canalisations). Les augmentations de poids observees sont faibles, meme apres plus de 1000 heures de chauffage a 350 deg. C, mais l'oxydation semble se poursuivre lineairement. De plus, l'oxyde forme dans le gaz carbonique sous pression de 15 kg/cm{sup 2} est nettement plus compact et adherent que celui forme sous pression atmospherique de gaz carbonique. Enfin, dans la pratique, les surfaces d'acier du circuit de gaz carbonique sont necessairement sablees ou decapees; une phosphatation ulterieure le protege de la corrosion atmospherique pendant le montage. Ces traitements sont sans influence sur le comportement de ces aciers dans le gaz carbonique a chaud. (auteur)

  6. Gas transport through porous media; Sur le transport des gaz a travers les milieux poreux

    Energy Technology Data Exchange (ETDEWEB)

    Breton, J P [Commissariat a l' Energie Atomique Saclay (France). Centre d' Etudes Nucleaires

    1968-06-01

    In the first part of this work we derive a rigorous transport theory for a mixture of gases passing through a bed of spheres, when the temperature is uniform. We solve the Boltzmann equation, putting boundary conditions in the solution. Two different methods are used, according to the nature of the flow. The second part deals with the experimental work: measurements of permeability, of separation and of interdiffusion. In the last part, with the help of the new theory presented here, we are for the first time able to explain all the experimental data. (author) [French] Dans la premiere partie de ce travail nous developpons une theorie rigoureuse du transport d'un melange de gaz a travers un lit de spheres, quand la temperature est uniforme. Nous integrons l'equation de Boltzmann en introduisant des conditions aux limites dans la solution. Nous utilisons deux methodes differentes selon le regime d'ecoulement. La seconde partie est consacree a l'etude experimentale: mesures de permeametrie, de separation et d'interdiffusion. Dans la derniere partie, a l'aide de la nouvelle theorie developpee ici, nous expliquons tous les resultats experimentaux, ce qui n'avait pas ete fait jusque la. (auteur)

  7. Gas market is today strategical; Le marche du gaz est aujourd'hui strategique

    Energy Technology Data Exchange (ETDEWEB)

    Darricarrere, Y.L. [Total, 92 - Courbevoie (France)

    2006-07-01

    The energy market, and in particular the gas market, is today seething with excitement. In France, in Europe and in the rest of the world, the energy stakes are in the center of preoccupations. This article is an interview of Y.L. Darricarrere, general director of the gas and electricity division of Total group, who explains his opinions about the opening of European and French energy markets, presents the ambitions of Total group on these markets, and comments some recent events of the European energy scene: concentration between gas and electric utilities, the Suez and Gaz de France (GdF) project of merger, the risks linked with the coming in of national companies from producing countries, like Gazprom and Sonatrach, on the European market, the restriction of access of foreign companies to hydrocarbon reserves in Russia and Latin America (come back of the 'energy nationalism'), Total's policy for anticipating the increase of the world energy demand and the depletion of fossil fuel reserves. (J.S.)

  8. Les techniques de séparation de gaz par membranes Gas Separation Techniques by Membranes

    Directory of Open Access Journals (Sweden)

    Avrillon R.

    2006-11-01

    Full Text Available Deux types de membranes peuvent être utilisés pour la séparation des gaz. Les unes sont poreuses et séparent les gaz sur la base de leur masse moléculaire selon un mécanisme de diffusion de Knudsen dans des micropores. Les facteurs de séparation obtenus sont généralement trop faibles pour présenter un intérêt industriel. Les autres, appelées membranes non poreuses, mettent en oeuvre un mécanisme de dissolution-diffusion des gaz dans une fine couche de polymère dénuée de toute porosité. C'est de ces dernières que nous allons parler. Commencé il y a une vingtaine d'années, le développement de ce type de membranes a conduit aux premières applications industrielles en 1979 avec l'introduction par Monsanto des séparateurs PRISM pour la récupération d'hydrogène à partir de différents gaz de raffinerie et de pétrochimie. Après des débuts modestes par suite de la compétition avec des technologies éprouvées comme la cryogénie, l'adsorption et l'absorption, la perméation gazeuse est en train de conquérir sa place parmi les techniques de séparation de gaz. Elle est aujourd'hui l'une des techniques membranaires présentant le plus fort taux de progression (30 % par an. Après un rappel des principes de base de la perméation gazeuse on abordera successivement les points suivants : - le choix du polymère constituant la couche séparatrice, - l'élaboration des membranes à structure asymétrique présentant une peau dense et fine, - les principales applications industrielles. Cela permettra de mettre en évidence les avantages et les limitations actuelles de la perméation gazeuse et de souligner les différents domaines où les efforts de R et D peuvent amener des progrès significatifs. Principle of Gas permeation - Gas permeation is a technique for fractionating gas mixtures by using nonporous polymer membranes having a selective permeability to gas according to a dissolution-diffusion mechanism. Gas is made to pass

  9. Ecoulements intermittents de gaz et de liquide en conduite verticale Intermittent Gas and Liquid Flows in a Vertical Pipe.

    Directory of Open Access Journals (Sweden)

    Line A.

    2006-11-01

    Full Text Available Le modèle présenté ici permet la pré-détermination du gradient de pression, du taux global de gaz, et de grandeurs caractéristiques de l'intermittence, dans un écoulement à poches et bouchons en conduite verticale. L'écriture des lois de conservation en moyenne phasique conditionnelle conduit à la définition d'une cellule moyenne équivalente. La fermeture du modèle est assurée par des lois de contrainte de cisaillement film-paroi, film-poche, bouchon-paroi, par une loi d'arrachage du gaz au culot de la poche, une loi de glissement du gaz dans les bouchons et par une loi de la vitesse moyenne de propagation des fronts de poches. Le calibrage et la qualification du modèle s'appuient sur deux banques de données, dont l'une a été obtenue avec des fluides pétroliers dans des conditions proches des situations industrielles (boucle diphasique de Boussens. The model described here can be used to predetermine the pressure gradient, the overall gas rate and the characteristic intermittence magnitudes in pocket and slug flow in a vertical pipe. The way governing equations in the conditional phase average are written defines an equivalent average cell. The model is closed by film/wall, film/pocket and slug/wall shear-stress laws, by a pulloff law for the gas at the bottom of the pocket, a slippage law for the gas in the slugs, and a mean propagation velocity law for the pocket fronts. The calibration and qualification of the model are based on two data banks, one of which contains data on petroleum fluids under conditions close to industrial situations (two-phase loop at Boussens.

  10. Kinetic study of the reaction of uranium with various carbon-containing gases; Etude cinetique de la reaction sur l'uranium de differents gaz carbones

    Energy Technology Data Exchange (ETDEWEB)

    Feron, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1963-09-15

    The kinetic study of the reaction U + CO{sub 2} and U + CO has been performed by a thermogravimetric method on a spherical uranium powder, in temperature ranges respectively from 460 to 690 deg. C and from 570 to 850 deg. C. The reaction with carbon dioxide leads to uranium dioxide. A carbon deposition takes place at the same time. The global reactions is the result of two reactions: U + 2 CO{sub 2} {yields} UO{sub 2} + 2 CO U + CO{sub 2} {yields} UO{sub 2} + C The reaction with carbon monoxide leads to a mixture of dioxide UO{sub 2}, dicarbide UC{sub 2} and free carbon. The main reaction can be written. U + CO {yields} 1/2 UO{sub 2} + 1/2 UC{sub 2} The free carbon results of the disproportionation of the carbon monoxide. A remarkable separation of the two phases UO{sub 2} and UC{sub 2} can be observed. A mechanism accounting for the phenomenon has been proposed. The two reactions U + CO{sub 2} and U + CO begin with a long germination period, after which, the reaction velocity seems to be limited in both cases by the ionic diffusion of oxygen through the uranium dioxide. (author) [French] L'etude cinetique des reactions U sol + CO{sub 2} gaz et U sol + CO gaz a ete effectuee par thermogravirnetrie sur une poudre d'uranium a grains spheriques, les domaines de temperature etudies s'etendant respectivement de 460 a 690 deg. C et de 570 a 850 deg. C. L'action du dioxyde de carbone conduit au dioxyde d'uranium UO{sub 2}; il se produit en meme temps un depot de carbone. La reaction globale resulte des deux reactions: U + 2 CO{sub 2} {yields} UO{sub 2} + 2 CO U + CO{sub 2} {yields} UO{sub 2} + C Le mono-oxyde de carbone conduit a un melange de dioxyde UO{sub 2}, de dicarbure UC{sub 2} et de carbone libre. La reaction principale s'ecrit: U + CO {yields} 1/2 UO{sub 2} + 1/2 UC{sub 2} Le carbone libre provient de la dismutation du mono-oxyde de carbone. On observe une separation remarquable des deux phases UO{sub 2} et UC{sub 2}; un mecanisme rendant compte de ce phenomene a

  11. A Geochemical Approach for Monitoring a CO2 Pilot Site: Rousse, France. A Major gases, CO2-Carbon Isotopes and Noble Gases Combined Approach Une méthode géochimique pour la surveillance d’un site pilote de stockage de CO2 : Rousse, France. Approche combinant les gaz majeurs, l’isotopie du carbone du CO2 et les gaz rares

    Directory of Open Access Journals (Sweden)

    Garcia B.

    2012-02-01

    storage pilot suggest that noble gas compositions produced by oxyfuel process are sufficiently exotic compared to compositions found in nature (reservoir, aquifer and air to be directly used as tracers of the injected CO2, and to detect and quantify leaks at soil and aquifer levels. Ce papier presente la caracterisation geochimique des differents gaz, naturels et anthropogeniques, impliques dans un pilote de stockage de CO2 en champ de gaz naturel appauvri (Rousse, France. Dans ce pilote, le CO2 est produit par oxycombustion d’un gaz naturel transforme en gaz domestique a l’usine de Lacq. Ce CO2 est transporte dans un pipeline de 30 km de longueur jusqu’au reservoir de gaz appauvri de Rousse. Les gaz produits a Rousse avant injection de CO2, le gaz commercial de Lacq et le CO2 resultant de l’oxycombustion ont ete echantillonnes, ainsi que les gaz situes dans un puits de surveillance (a une profondeur de 45 m et les gaz du sol situes au voisinage de Rousse. Pour tous ces echantillons, la composition en gaz majeurs, la signature isotopique du carbone ainsi que l’abondance et signature isotopique des gaz rares ont ete determinees. Les compositions gazeuses du gaz naturel de Rousse sont comparables a celle du gaz domestique de Lacq avec le methane comme compose principal et la fraction C2-C5 et CO2 comme gaz residuels. Les gaz des sols refletent typiquement des melanges entre l’air (pole pur et le CO2 d’origine biogenique (avec des teneurs maximales de l’ordre de 9-10 %, tandis que les gaz presents dans le puits de monitoring refletent typiquement la composition de l’air sans exces de CO2. Le gaz de Rousse et le gaz domestique du site de Lacq ont une composition isotopique δ13CCH4 egale a –41,0 ‰ et –43,0 ‰ respectivement. Le CO2 injecte sur Rousse a une composition isotopique δ13CCO2 egale a –40,0 ‰ a la sortie de la chambre d’oxycombustion, tandis que la composition isotopique δ13CCO2 des gaz des sols est comprise entre –15 et –25

  12. Heavy water moderated gas-cooled reactors; Filiere eau lourde - gaz

    Energy Technology Data Exchange (ETDEWEB)

    Bailly du Bois, B; Bernard, J L; Naudet, R; Roche, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    France has based its main effort for the production of nuclear energy on natural Uranium Graphite-moderated gas-cooled reactors, and has a long term programme for fast reactors, but this country is also engaged in the development of heavy water moderated gas-cooled reactors which appear to present the best middle term prospects. The economy of these reactors, as in the case of Graphite, arises from the use of natural or very slightly enriched Uranium; heavy water can take the best advantages of this fuel cycle and moreover offers considerable development potential because of better reactor performances. A prototype plant EL 4 (70 MW) is under construction and is described in detail in another paper. The present one deals with the programme devoted to the development of this reactor type in France. Reasons for selecting this reactor type are given in the first part: advantages and difficulties are underlined. After reviewing the main technological problems and the Research and Development carried out, results already obtained and points still to be confirmed are reported. The construction of EL 4 is an important step of this programme: it will be a significant demonstration of reactor performances and will afford many experimentation opportunities. Now the design of large power reactors is to be considered. Extension and improvements of the mechanical structures used for EL 4 are under study, as well as alternative concepts. The paper gives some data for a large reactor in the present state of technology, as a result from optimization studies. Technical improvements, especially in the field of materials could lead to even more interesting performances. Some prospects are mentioned for the long run. Investment costs and fuel cycles are discussed in the last part. (authors) [French] La France, qui a base son effort principal pour la production d'energie nucleaire sur la filiere des reacteurs a uranium naturel et graphite refroidis par gaz, et qui a un programme a plus

  13. Suez-Gaz de France merger, E.ON's public takeover bid on Endesa... The new energy fight

    International Nuclear Information System (INIS)

    Lepetit, V.; Rouaud, P.O.; Mairet, C.

    2006-01-01

    The energy sector is in fever. In less than a week (February 21 to 26, 2006), the Europe of energy has fallen into a frenzy of mergers and acquisitions: the German E.ON offered 29.1 billion euros to get the Spanish Endesa, Electricite de France (EdF), who already got the Italian Edison in 2005, is ready for more major acquisitions, the Italian Enel is candidate for the repurchasing of Suez, while Gaz de France (GdF) and Suez have started a surprise merger. The stake of this match between giants is their growing up and the penetration of foreign markets before their complete liberalization in July 2007. The potential victims of these actions are the competition and the clients, the industrial ones first. (J.S.)

  14. Fractionation of Hydrocarbons Between Oil and Gas Phases Fractionnement des hydrocarbures entre les phases huile et gaz

    Directory of Open Access Journals (Sweden)

    Ruffier-Meray V.

    2006-12-01

    expliquer certains phénomènes de migration. Lors de l'injection de gaz, la dissolution préférentielle de certains constituants dans le gaz peut modifier la composition et le comportement le l'huile en place. Le stockage souterrain de gaz dans des réservoirs contenant encore de l'huile peut également être concerné par ce problème. Des études ont été menées à l'IFP, dans le cadre de différents projets, de façon à mettre en évidence ce phénomène et à le quantifier. Deux d'entre elles, qui concernent la géochimie de réservoir, ont été menées sur des fluides réels. La troisième étude, qui est un test de gonflement, concerne l'injection de gaz, le fluide considéré est un mélange synthétique comprenant des hydrocarbures jusqu'à C30. Les équipements utilisés sont, d'une part, une cellule saphir ayant une pression maximale d'utilisation de 400 bar, et d'autre part un équipement appelé Hercule dont la pression maximale d'utilisation est de 1500 bar. Pour chacun des fluides étudiés, la pression de saturation a été mesurée. Pour plusieurs paliers, inférieurs à la pression de saturation, les phases liquides et gazeuses à l'équilibre ont été prélevées à pression constante et analysées. Dans le cas de l'injection de gaz, les compositions à l'équilibre ont été déterminées pour des mélanges contenant des quantités variables de gaz. Par rapport aux n-alcanes de même nombre d'atomes de carbone, les hydrocarbures aromatiques restent préférentiellement dans la phase liquide, de même que les cycloalcanes pour lesquels ce phénomène est moins net toutefois. Par contre, la phase gazeuse s'enrichit légèrement en isoalcanes. Ces phénomènes de fractionnement sont moins marqués au voisinage de la région critique. Ils ont été modélisés au moyen d'une équation d'état cubique assortie d'une règle de mélange par contribution de groupes.

  15. Natural gas air conditioning in the tertiary sector. Ambitions, realizations and tools; Climatisation au gaz naturel dans le tertiaire. Ambitions, realisations et outils

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-04-01

    This meeting, organized by the research center of Gaz de France (Cegibat), makes a status of the market of natural gas air conditioning in office and public buildings: experience feedback, improvements of the technology, available tools. After a brief presentation of the status and perspectives of this market in France, the representatives of different companies involved in the fitting of natural gas air conditioning systems present their point of view about this technology. A last part presents the 'climogaz.com' tool launched by Gaz de France. It consists in a web site devoted to the share of knowledge and experience about this technology between professionals and applied to hotels, swimming pools, office buildings, food trade and other trades. (J.S.)

  16. The performances of natural gas infrared radiation in paints baking; Les performances de l`infrarouge gaz pour la cuisson des peintures

    Energy Technology Data Exchange (ETDEWEB)

    Lourdou, I. [Gaz de France, 75 - Paris (France). Centre d`essais de recherches sur les utilisations du gaz

    1998-04-01

    The direction of research of Gaz de France (GdF) company, in association with the centre for technical studies of aeraulic and thermal industries (CETIAT), has carried out infrared radiation baking tests on real painted parts using natural gas burners. Tests were performed on the Erica test facility. The development of the use of infrared gas burners in the mechanical industry requires an optimum use of this technology in the baking cycle. (J.S.)

  17. Gaz de France first quarter 2007 sales: an 11 per cent drop due to an exceptionally warm winter: a 1.3 per cent increase on an average-climate basis. Non-audited IFRS data

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Paris, May 14 2007 - For the first quarter 2007, Gaz de France Group posted euro 9,053 million in consolidated sales. This 11 per cent decrease on the same period in 2006 is a direct result of the extremely warm weather conditions in France and Europe this winter. In contrast, under average climate conditions sales improved by 1.3 per cent. In France, where the winter of 2006/2007 was the warmest in fifty years, sales were impacted by 18 billion kWh in the quarter compared to a quarter with average-climate conditions and 32 billion kWh compared to the first quarter 2006 which, in contrast, was colder than normal. The impact of the weather had similar effects on sales outside France. The highly unusual weather conditions also had an indirect impact on the market and, consequently, on both gas production and the arbitrage activities. Not withstanding these effects, the Group continued to consolidate its position in foreign markets, with sales outside France reaching euro 3,341 million. The share of sales outside France increased by 3 points in the first quarter of 2007 versus first quarter 2006 to 37 per cent as at end March 2007. The group reiterates the 2007 financial objective as presented at the full year 2006 results: '2007 will be a year of consolidation and the EBITDA should be in line with that of 2006'.

  18. Gaz de France first quarter 2007 sales: an 11 per cent drop due to an exceptionally warm winter: a 1.3 per cent increase on an average-climate basis. Non-audited IFRS data

    International Nuclear Information System (INIS)

    2007-01-01

    Paris, May 14 2007 - For the first quarter 2007, Gaz de France Group posted euro 9,053 million in consolidated sales. This 11 per cent decrease on the same period in 2006 is a direct result of the extremely warm weather conditions in France and Europe this winter. In contrast, under average climate conditions sales improved by 1.3 per cent. In France, where the winter of 2006/2007 was the warmest in fifty years, sales were impacted by 18 billion kWh in the quarter compared to a quarter with average-climate conditions and 32 billion kWh compared to the first quarter 2006 which, in contrast, was colder than normal. The impact of the weather had similar effects on sales outside France. The highly unusual weather conditions also had an indirect impact on the market and, consequently, on both gas production and the arbitrage activities. Not withstanding these effects, the Group continued to consolidate its position in foreign markets, with sales outside France reaching euro 3,341 million. The share of sales outside France increased by 3 points in the first quarter of 2007 versus first quarter 2006 to 37 per cent as at end March 2007. The group reiterates the 2007 financial objective as presented at the full year 2006 results: '2007 will be a year of consolidation and the EBITDA should be in line with that of 2006'

  19. Etude du déplacement de l'huile par le gaz Analysis of Oil Displacement by Gas

    Directory of Open Access Journals (Sweden)

    Delclaud J.

    2006-11-01

    Full Text Available Les ingénieurs « réservoir u prévoient avec beaucoup de difficultés l'exploitation des gisements en utilisant les relations perméabilités relatives-saturations fournies par les laboratoires. Ceci amène à se demander si le concept est valide en écoulement transitoire, si les mesures sont effectuées selon des procédures convenables, si la relation statique entre la pression capillaire et la saturation est conservée en régime variable, si enfin la méconnaissance des lois de combinaison de ces fonctions n'est pas la cause de l'insatisfaction des ingénieurs. Le travail présenté ici traite des trois premiers points. Deux séries d'expériences sont réalisées à cet effet : - d'une part, des expériences de déplacement de l'huile par le gaz, où l'on s'intéresse à l'établissement et à la caractérisation de phénomènes pseudo-stationnaires. Les échantillons poreux choisis sont de faibles dimensions. Ils permettent ainsi de réduire la durée des périodes transitoires; - d'autre part, des expériences de déplacement sur des échantillons homogènes de grandes dimensions où l'on étudie les phénomènes transitoires. On mesure, tout au long du massif, la pression dans les deux phases et la saturation. Les perméabilités relatives sont calculées en tout point et à tout instant, à partir des équations de continuité. II ressort de ces travaux que la relation perméabilité relative-saturation est la même en tout point du milieu poreux, tout au long de l'écoulement transitoire, qu'elle ne dépend pas de la vitesse d'écoulement et que la relation pression capillaire-saturation coïncide avec celle établie par la méthode des états restaurés. La validité du concept en écoulement transitoire est donc prouvée. La méthode de WELGE, JOHNSON, BOSSLER et NAUMANN conduit à des résultats différents de ceux obtenus. On montre, pour expliquer ces écarts, que les hypothèses théoriques de cette méthode sont

  20. Study of new structures adapted to gas-graphite and gas-heavy water reactors; Etude de structures nouvelles adaptees aux reacteurs graphite-gaz et eau lourde-gaz

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R; Roche, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    'EDF d'une part, les conclusions des etudes et essais effectues hors pile d'autre part, conduisent a un changement considerable de la physionomie des reacteurs de la filiere Graphite-Gaz, Les principales modifications envisagees sont analysees dans la communication. L'adoption d'un element combustible annulaire et d'un soufflage descendant permettront d'accroitre considerablement la puissance specifique et la puissance developpee par canal; il en resultera une reduction sensible du nombre des canaux et un accroissement correlatif de la maille du reseau - L'empilement de graphite devra etre adapte a ces nouvelles conditions - Des raisons de securite conduisent a generaliser l'emploi du beton precontraint pour la construction du caisson; elles pourront amener a integrer a l'interieur de celui-ci les echangeurs et l'appareil de manutention du combustible (dispositif dit: 'en grenier'). Une maquette en vraie grandeur de ce grenier a ete construite a Saclay avec la participation d'EURATOM; les resultats d'exploitation en sont presentes, ainsi que des idees de barres de controle de conception nouvelle. En ce qui concerne la filiere Eau-Lourde-Gaz, les etudes sont poursuivies dans deux voies principales; la premiere, qui conserverait l'usage de tubes de force horizontaux, tient compte de l'experience acquise au cours de la construction du reacteur EL4 dont elle constituerait une extrapolation; la seconde, inspiree des etudes poursuivies au titre de la filiere Graphite-Gaz, ferait appel a un caisson en beton precontraint pour tenir la pression, le moderateur etant sensiblement a la pression du fluide refrigerant et le combustible etant dispose dans des canaux verticaux. Les merites respectifs de ces deux variantes sont analyses dans la communication. (auteurs)

  1. Corrosion by cooling gases in nuclear reactors; la corrosion par les gaz caloporteurs dans les reacteurs nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre de Saclay, Section d' etude de la corrosion par gaz et metaux liquides (France)

    1960-07-01

    This article begins with a review of the various materials which can be used and the cooling gases in which they may be heated, emphasis being placed on the importance of reaching temperatures as high as possible. This is followed by a few general remarks on the dry oxidation of metals and alloys, particularly with regard to diffusion phenomena and their various possible mechanisms, and also the methods of investigation employed. Finally, the behaviour of the chief nuclear materials heated in the various gases is studied successively. Materials used for fuel (metallic uranium, uranium oxide, carbides and silicides), canning materials (magnesium, aluminium, zirconium, beryllium, stainless and refractory steels), structural materials (ordinary or slightly alloyed steels), and finally moderators (graphite, beryllium oxide) are deal with in this way. This account is backed up both by the results obtained at the CEA and by work published outside or abroad up to the present day. In conclusion, every effort has been made to direct future research on the basis of the foregoing. Reprint of a paper published in Industries Atomiques - no. 9/10, 1959, p. 3-23 [French] Dans cet article, on passe tout d'abord en revue les divers materiaux utilisables et les gaz de refroidissement dans lesquels ils peuvent etre chauffes, en insistant sur l'interet d'atteindre des temperatures aussi elevees que possible. On rappelle ensuite quelques generalites sur l'oxydation seche des metaux et alliages, notamment en ce qui concerne les phenomenes de diffusion et leurs divers mecanismes possibles ainsi que les methodes d'etude. Enfin, le comportement des principaux materiaux nucleaires chauffes dans les divers gaz est etudie successivement. On traita ainsi des materiaux combustibles (uranium metallique, oxyde, carbures et siliciures d'uranium), des materiaux de gainage (magnesium, aluminium, zirconium, beryllium, aciers inoxydables et refractaires), des materiaux de structure (aciers ordinaires

  2. Problem Periods

    Science.gov (United States)

    ... ovary syndrome. Read our information on PCOS for teens , and see your doctor if you think you may have PCOS. Major weight loss. Girls who have anorexia will often stop having periods. When to see ...

  3. Unconventional Gas Resources in the Paleozoic of Central Europe Ressources de gaz non conventionnels dans le Paléozoïque de l’Europe Centrale

    Directory of Open Access Journals (Sweden)

    Littke R.

    2011-05-01

    Full Text Available Whereas gas production from unconventional reserves has greatly increased over the past decades, there is still a largely unexplored potential in the Paleozoic of Central Europe. For this area, the paper summarizes some important aspects of the geology of tight sandstone gas reservoirs, gas shales and coalbed methane. Tight sandstones with low permeabilities are especially present in the Permian (Rotliegend Formation of The Netherlands and northern Germany, but also in the underlying Carboniferous. There is already active production from some of these reservoirs. Further development greatly depends on understanding of gas charge as well as the regional distribution of porosity and permeability which in turn depend on facies and diagenesis. In contrast exploration for gas shales is just at the very beginning. Whereas Mesozoic shales in the southern Lower Saxony Basin have to be regarded as prime targets due to thickness, maturity and organic matter content, there are additional targets in the Mississippian, but also in older rocks. Currently an international gas shale research programme (Gas shales in Europe, GASH gathers relevant data for these units. Coalbed methane exploration started already about 20 years ago in the Ruhr Basin, but was not successful at that time due to small flow rates. On the other hand, production from abandoned coal mines provided substantial amounts of gas. Due to the abundance of coal seams and the suitable maturity conditions and gas contents, there is a high potential for future substantial coalbed methane in the area. Alors que l’extraction du gaz naturel des gisements non conventionnels a fortement augmenté ces dernières dizaines d’années, un large potentiel de ressources reste inexploré dans les couches paléozoïques de l’Europe Centrale. Cet article présente, pour cette région, quelques aspects importants de la géologie des grès de faible perméabilité (tight gas sands, des gaz de schiste (gas

  4. No 3017. Resolution proposal aiming at creating an inquiry commission relative to the project of merger between Gaz de France and Suez, to the conditions of its preparation and announcement and to the consequences of Gaz de France privatization on users and on the energy market balance

    International Nuclear Information System (INIS)

    Balligand, J.P.; Ayrault, J.M.; Hollande, F.; Besson, E.; Migaud, D.; Emmanuelli, H.; Brottes, F.; Bataille, Ch.; Ducout, P.; Gaubert, J.; Habib, D.

    2006-04-01

    On February 25, 2006, the French government took the decision of merging together Gaz de France and Suez energy companies as an answer to Enel's project of takeover bid on Suez. This document wonders about: the real motivations of Gaz de France (the French gas utility) privatization, the possible intervention of public authorities in Enel and Veolia companies project of controlling the Suez group, the governing way of the share-holding government and the preservation of its industrial interests, and the consequences for consumers. Therefore, the creation of a parliamentary inquiry commission is requested to shade light on these different points and to give notice of any bad practices in this affair. (J.S.)

  5. Detector for the liquid carried over in a gas; Detecteur d'entrainement de liquide dans un gaz

    Energy Technology Data Exchange (ETDEWEB)

    Delisle, J P; Eperonnat, P; Lions, N [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1965-07-01

    This report describes an optical detector for the detection of a liquid carried over by a gas. The device is sensitive to a cumulated quantity of liquid equal to a few cubic millimetres and is capable of operating an alarm from a distance. The prototype was constructed and tested as detector for the oil leaking in the argon compressed by a diaphragm compressor. A patent for this apparatus under the number: P.V.954.703, has been deposited on 22.11.1963. (authors) [French] Ce rapport decrit un detecteur optique d'entrainement de liquide dans un gaz, sensible a une quantite cumulee de liquide entraine egale a quelques millimetres cubes. L'appareil peut actionner une alarme a distance. Le prototype a ete construit et essaye comme detecteur de fuites d'huile dans l'argon refoule par un compresseur a membranes. Une demande de brevet a ete deposee pour cet appareil sous le numero: P.V.954.703, le 22.11.1963. (auteur)

  6. Experimental contribution to the study of gas bearings; Contribution experimentale a l'etude des paliers a gaz

    Energy Technology Data Exchange (ETDEWEB)

    Gobert, G

    1962-07-01

    Developments for gas-lubricated bearings are discussed. The study of how the fluid film behaves compared to what one can expect is discussed. Various devices are described which have allowed us to go up to peripheral velocity greater than 400 m/s, leading to rotational speed of several thousand revolutions per second. This is obtained by using an automatic setting for the distance between fixed and rotating walls. (author) [French] Le present travail debute par un apercu de l'etat actuel des connaissances sur le processus de la lubrification, notamment sur les paliers a lubrification par gaz. Apres une analyse effectuee au moyen des recentes theories de R. Comolet sur le film fluide entre disques paralleles, nous decrivons des machines dont les charges axiales et radiales specialement etudiees ont permis, au moyen d'un reglage automatique des jeux entre parois fixes et parois tournantes, d'atteindre des vitesses peripheriques superieures a 400 m/s correspondant a des vitesses de plusieurs milliers de tours par seconde. (auteur)

  7. Experimental contribution to the study of gas bearings; Contribution experimentale a l'etude des paliers a gaz

    Energy Technology Data Exchange (ETDEWEB)

    Gobert, G

    1962-07-01

    Developments for gas-lubricated bearings are discussed. The study of how the fluid film behaves compared to what one can expect is discussed. Various devices are described which have allowed us to go up to peripheral velocity greater than 400 m/s, leading to rotational speed of several thousand revolutions per second. This is obtained by using an automatic setting for the distance between fixed and rotating walls. (author) [French] Le present travail debute par un apercu de l'etat actuel des connaissances sur le processus de la lubrification, notamment sur les paliers a lubrification par gaz. Apres une analyse effectuee au moyen des recentes theories de R. Comolet sur le film fluide entre disques paralleles, nous decrivons des machines dont les charges axiales et radiales specialement etudiees ont permis, au moyen d'un reglage automatique des jeux entre parois fixes et parois tournantes, d'atteindre des vitesses peripheriques superieures a 400 m/s correspondant a des vitesses de plusieurs milliers de tours par seconde. (auteur)

  8. Contribution to the activation analysis of the rare gases. Contribution to the analysis of carbon monoxide and water vapour in gases (1963); Contribution a l'analyse par activation des gaz rares. Contribution a l'analyse de l'oxyde de carbone et de la vapeur d'eau dans les gaz (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Diebolt, J [Commisariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1963-07-15

    In the present work, we have applied radioactive analysis to the general technique of rare gas separation. This separation is carried out on active charcoal, at constant pressure. The desorption of the gas is caused by an increase in the initial temperature of adsorption. These separations are quantitative and can be confirmed by chemical analysis. The volumes of desorbed gas are measured by radioactive counting. We have also used radioactivation to study the reduction of palladous chloride by carbon monoxide. Since this reduction is quantitative, we can have a knowledge of the mass of palladium reduced by measuring its activity. We have used the property which have organic chlorides of being hydrolysed by water vapour and of liberating hydrochloric acid to study quantitatively the amount of water vapour which a gas contains. The hydrochloric acid formed is measured by activation of the chlorine in the acid. (author) [French] Dans les travaux que nous presentons, nous avons applique l'analyse par radioactivation, a la technique generale de separation des gaz rares. Cette separation est faite sur charbon active, a pression constante. La desorption des gaz est provoquee par une augmentation de la temperature initiale d'adsorption. Ces separations sont quantitatives, et peuvent etre exploitees par l'analyse chimique. Les volumes de gaz dedorbes sont mesures par comptage de la radioactivite. Nous avons egalement utilise la radioactivation pour l'etude de la reduction du chlorure palladeux par l'oxyde de carbone. Cette reduction etant quantitative, nous pouvons connaitre la masse de palladium reduit par la mesure de son activite. Nous avons exploite la propriete que possede un chlorure organique d'etre hydrolise par la vapeur d'eau et de liberer de l'acide chlorhydrique pour etudier quantitativement la vapeur d'eau contenue dans un gaz. L'acide chlorhydrique forme est mesure par l'activation du chlore de l'acide. (auteur)

  9. Contribution to the dosimetry of tritium in the presence of inactive or active gases; Contribution a la dosimetrie du tritium en presence de gaz inactifs ou actifs

    Energy Technology Data Exchange (ETDEWEB)

    Soudain, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1966-07-01

    Tritium is a dangerous gas for man and the maximum admissible doses in the atmosphere are sufficiently low for the dosage to be fairly difficult. We have developed an apparatus for measuring selectively the contamination of air by this gas when it is alone or when it is associated with other gaseous contaminants. The differential apparatus using two ionization chambers makes it possible to eliminate a parasitic {gamma} radiation field. In a few particular cases, the presence of the radio-active gas has been studied. From the practical point of view, the use of these chambers made of stainless steel makes for easier use since the problems connected with wall adsorption have been satisfactorily resolved. The method can be applied without restriction and very easily to the dosage of traces tritium in air or in the form of tritiated water or tritiated steam in the atmosphere. (author) [French] Le tritium est un gaz dangereux pour l'homme et les concentrations maximales admissibles dans l'atmosphere sont suffisamment basses pour que le dosage soit delicat. Nous avons etudie et realise un appareil qui permet de mesurer selectivement la contamination de l'air par ce gaz lorsqu'il est seul ou lorsqu'il est associe a d'autres agents gazeux contaminants. Le montage differentiel a deux chambres d'ionisation permet d'eliminer un champ de rayonnement {beta} parasite. Dans certains cas particuliers, la presence du gaz radioactif a ete etudiee. Sur le plan pratique, l'utilisation des chambres en acier inoxydable facilite les applications car les problemes d'adsorption aux parois ont ete bien resolus. La methode peut s'appliquer sans restriction et tres pratiquement au dosage des traces de tritium dans l'air ou encore sous forme d'eau tritiee ou de vapeur d'eau tritiee dans l'atmosphere. (auteur)

  10. Modélisation d'une détente quasi-isotherme d'un gaz par contact direct avec un fluide caloporteur

    OpenAIRE

    Blaise , Mathilde; Maillet , Denis; Feidt , Michel; Alemany , Antoine; Forcinetti , Renato

    2015-01-01

    National audience; Les besoins en électricité sont croissants, cependant, les rejets thermiques industriels sont peu valorisés. La reconsidération des moteurs à apport de chaleur externe est un enjeu d'actualité pour la valorisation des rejets thermiques. Dans ces derniers, la phase de détente motrice offre des possibilités d'amélioration. L'idée ici est d'accompagner cette étape par un apport de chaleur par contact direct avec un fluide caloporteur. En effet, la détente d'un gaz entre une ha...

  11. Mass-spectrometric analysis of trace oxygen in carbon dioxide; Analyse de traces d'oxygene dans le gaz carbonique par spectrometrie de masse

    Energy Technology Data Exchange (ETDEWEB)

    Nief, G; Severin, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The mass spectrum of pure CO{sub 2} contains a peak of weight 32 whose relationship to peak at 44 varies greatly depending on the previous history of the source of ions and even during the course of an analysis. The fact that this peak is more or less proportional to the pressure and that its appearance potential is the same as that of oxygen leads us to suppose that it is produced from oxygen formed by dissociation of the carbon dioxide on the tungsten filament. A prior treatment of the ion source with acetylene reduces the ratio 32/44 to a value of about 15.10{sup -5}. This same treatment also stabilises the spectrometer's sensitivity to oxygen. Two lines of introduction enable pure carbon dioxide, the specimen to be estimated and a reference mixture of known oxygen content to be sent into the mass spectrometer in quick succession. Oxygen in the carbon dioxide in amounts ranging between 0 and 500 p.p.m. can thus be determined to an accuracy of {+-} 5 p.p.m., the analysis taking 30 minutes. (author) [French] Le spectre de masse de CO{sub 2} pur contient un pic de masse 32 dont le rapport au pic 44 varie enormement suivant l'histoire anterieure de la source d'ions et meme au cours d'une analyse. Le fait que ce pic soit grossierement proportionnel a la pression et que son potentiel d'apparition soit le meme que celui de l'oxygene permet de supposer qu'il est engendre a partir de l'oxygene produit par dissociation du gaz carbonique sur le filament de tungstene. Un conditionnement prealable de la source d'ions avec de l'acetylene reduit le rapport 32/44 a une valeur d'environ 15.10{sup -5}. Ce meme traitement stabilise egalement la sensibilite du spectrometre vis-a-vis de l'oxygene. Une double ligne d'introduction de gaz permet d'envoyer en successions rapides dans le spectrometre de masse le gaz carbonique pur, l'echantillon a doser et un melange de reference de teneur en oxygene connue. On arrive ainsi a doser l'oxygene dans le gaz carbonique dans la gamme de 0 a

  12. Dosage du mercure dans le gaz naturel par absorption atomique sans flammes Mercury Titration in Natural Gas by Flameless Atomic Absorption

    Directory of Open Access Journals (Sweden)

    La Villa F.

    2006-11-01

    Full Text Available Cet article présente la méthode mise au point par l'Institut Français du Pétrole pour déterminer par absorption atomique sans flamme, les traces de mercure métallique contenu dans un gaz naturel. La méthode d'analyse nécessite une extraction du mercure soit sous forme d'ion mercurique en faisant passer le gaz dans une solution oxydante, soit sous forme d'amalgame avec de l'or ou de l'argent. Le premier mode opératoire s'applique aux échantillons dont la concentration en mercure est supérieure à I ttg/Nm3, le second pour des concentrations inférieures à 5 pg/Nm3. Les seuils de détection sont respectivement 10 ng (en solution et 0,3 ng (en amalgame. La répétabilité pour 100 ng de mercure (en amalgame est de ± 7% pour une probabilité de.95 %. En conclusion, dans un échantillon de gaz naturel, compte tenu du volume des prélèvements effectués, il est possible de détecter des concentrations de l'ordre du nanogramme de mercure par mètre cube de gaz. This article describes the method developed by IFP using flameless atomic absorption to determine metallic mercury traces in a natural gas. The analyst method requires a mercury extraction either in the form of mercuric ions by making the gas pass through an oxidizing solution or in the form of an amalgam with gold or silver. The former operating method applies ta samples having a mercury concentration greater than I !ag/Nm3, and the latter for concentrations smaller than 5 (-Lg/Nm3. Detection thresholds are respectively 10 ng (in solution and 0.3 ng (in amalgam. The repeatability for 100 ng of mercury (in amalgam is ± 7 % with a probability of 95%. To conclude, in a sample of natural gas, considering the volume of the samples taken, it is possible ta detect concentrations in the vicinity of one nanogrom of mercury per cubic meter of gas.

  13. Can-rupture detection in gas-cooled nuclear reactors; La detection des ruptures de gaine dans les piles nucleaires refroidies par gaz

    Energy Technology Data Exchange (ETDEWEB)

    Roguin, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    Can-rupture detection (DRG) is one important aspect of pile safety, more particularly so in the case of gas-cooled reactors. A rapid and sure detection constitutes also an improvement as far as the efficiency of electricity-producing nuclear power stations are concerned. Among the numerous can-rupture detection methods, that based on the measurement of the concentration of short-lived fission gases in the heat-carrying fluid has proved to be the most sensitive and the most rapid. A systematic study of detectors based on the electrostatic collection of the daughter products of fission gases has been undertaken with a view to equip the reactors EL 2, G 3, EDF 1, EDF 2 and EDF 3, the gas loops of PEGASE and EL 4. The different parameters are studied in detail in order to obtain a maximum sensitivity and to make it possible to construct detection devices having the maximum operational reliability and requiring the minimum maintenance. The primary applications of these devices are examined in the case of the above-mentioned reactors. (author) [French] La Detection des Ruptures de Gaines (D. R. G.) est un aspect important de la securite des piles et plus particulierement des piles refroidies par un gaz. Une detection rapide et sure constitue aussi un element d'amelioration du rendement des centrales nucleaires productrices d'energie electrique. Parmi les nombreuses methodes de detection des ruptures de gaines, la mesure de la concentration dans le fluide caloporteur des gaz de fission a vie courte s'est revelee comme la plus sensible et la plus rapide. Une etude systematique des detecteurs a collection electrostatique des descendants des gaz de fission a ete entreprise en vue d'equiper les piles EL 2, G 3, EDF 1, EDF 2 et EDF 3, les boucles a gaz de la pile Pegase et la pile EL 4. Les divers parametres sont etudies en detail pour obtenir une sensibilite maximum et permettre la realisation de dispositifs de detection ayant le maximum de securite de

  14. Starting up a programme of atomic piles using compressed gas; Le demarrage d'un programme de piles atomiques a gaz comprime

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, J; Yvon, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-07-01

    1) An examination of the intellectual and material resources which have directed the French programme towards: a) the natural uranium and plutonium system, b) the use of compressed gas as heat transfer fluid (primary fluid). 2) The parts played in exploring the field by the pile EL2 and G1, EL2 a natural uranium, heavy water and compressed gas pile, G1 a natural uranium, graphite and atmospheric air pile. 3) Development of the neutronics of graphite piles: physical study of G1. 4) The examination of certain problem posed by centres equipped with natural uranium, graphite and compressed carbon dioxide piles: structure, special materials, fluid circuits, maximum efficiency. Economic aspects. 5) Aids to progress: a) piles for testing materials and for tests on canned fuel elements, b) laboratory and calculation facilities. 6) Possible new orientations of compressed gas piles: a) raising of the pressure, b) enriched fuel, c) higher temperatures, d) use of heavy water. (author) [French] 1) Examen des ressources - intellectuelles et materielles - qui ont oriente le programme fran is vers: a) la voie de l'uranium naturel et du plutonium; b) l'emploi comme fluide pour le transfert de la chaleur (fluide primaire) d'un gaz comprime. 2) Le role d'exploration des piles EL2 et G1, EL2 pile a uranium naturel, eau lourde et gaz comprime, G1 pile a uranium naturel, graphite et air atmospherique. 3) Developpement de la neutronique des piles a graphite: l'etude physique de G1. 4) Examen de certains problemes poses par les centrales equipees de piles a uranium naturel, graphite et gaz carbonique comprime: structure, materiaux speciaux, circuits de fluides, optimisation. Aspects economiques. 5) Les auxiliaires du progres: a) piles pour essai de materiaux et pour essais de cartouches, b) moyens de laboratoire et moyens de calcul. 6) Orientations nouvelles possibles des piles a gaz comprime: a) elevation de la pression, b) combustible enrichi, c) temperatures elevees, d) emploi de l

  15. Can-rupture detection in gas-cooled nuclear reactors; La detection des ruptures de gaine dans les piles nucleaires refroidies par gaz

    Energy Technology Data Exchange (ETDEWEB)

    Roguin, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    Can-rupture detection (DRG) is one important aspect of pile safety, more particularly so in the case of gas-cooled reactors. A rapid and sure detection constitutes also an improvement as far as the efficiency of electricity-producing nuclear power stations are concerned. Among the numerous can-rupture detection methods, that based on the measurement of the concentration of short-lived fission gases in the heat-carrying fluid has proved to be the most sensitive and the most rapid. A systematic study of detectors based on the electrostatic collection of the daughter products of fission gases has been undertaken with a view to equip the reactors EL 2, G 3, EDF 1, EDF 2 and EDF 3, the gas loops of PEGASE and EL 4. The different parameters are studied in detail in order to obtain a maximum sensitivity and to make it possible to construct detection devices having the maximum operational reliability and requiring the minimum maintenance. The primary applications of these devices are examined in the case of the above-mentioned reactors. (author) [French] La Detection des Ruptures de Gaines (D. R. G.) est un aspect important de la securite des piles et plus particulierement des piles refroidies par un gaz. Une detection rapide et sure constitue aussi un element d'amelioration du rendement des centrales nucleaires productrices d'energie electrique. Parmi les nombreuses methodes de detection des ruptures de gaines, la mesure de la concentration dans le fluide caloporteur des gaz de fission a vie courte s'est revelee comme la plus sensible et la plus rapide. Une etude systematique des detecteurs a collection electrostatique des descendants des gaz de fission a ete entreprise en vue d'equiper les piles EL 2, G 3, EDF 1, EDF 2 et EDF 3, les boucles a gaz de la pile Pegase et la pile EL 4. Les divers parametres sont etudies en detail pour obtenir une sensibilite maximum et permettre la realisation de dispositifs de detection ayant le maximum de securite de fonctionnement et le

  16. Compatibility of various magnesium alloys with pressurized carbon dioxide at high temperatures; Compatibilite de divers alliages de magnesium avec le gaz carbonique sous pression aux temperatures elevees

    Energy Technology Data Exchange (ETDEWEB)

    Dewanckel, B; David, R; Hulin, C; Leclercq, D [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

    1968-07-01

    This work on the compatibility of magnesium alloys with pressurized carbon dioxide has been carried out along three lines: - testing of special alloys containing additions of zirconium, manganese, cerium, zinc, beryllium and yttrium. The results are satisfactory, generally speaking, and the corrosion kinetics are often comparable to those of conventional magnesium-zirconium alloy; - influence of the quality of the carbon dioxide, in particular the presence of water vapour or of carbon monoxide in this gas. It appears that oxidation is reduced if the carbon dioxide contains traces of water vapour, but is more pronounced if carbon monoxide is also present; - study of certain phenomena related to corrosion: size changes in the samples during tests, structural modifications in the alloys (grain-size changes, formation of a cortical zone in the case of alloys containing zirconium). The influence of thermal cycling has also been studied in a few specific tests. The results obtained make it possible to compare the behaviour of various alloys under varying conditions of long-term use, and to choose, if required, the best composition for a given application. (authors) [French] Ce travail sur la compatibilite des alliages de magnesium avec le gaz carbonique sous pression a ete particulierement oriente dans trois directions: - epreuve, d'alliages speciaux comportant des additions de zirconium, manganese, cerium, zinc, beryllium et yttrium. Les resultats sont generalement satisfaisants et les cinetiques de corrosion souvent comparables a celles de l'alliage magnesium-zirconium classique; - influence de la qualite du gaz carbonique, et notamment de la presence de vapeur d'eau ou d'oxyde de carbone dans ce gaz. Il est apparu que l'oxydation est reduite si le gaz carbonique contient des traces d'eau, mais accrue si l'oxyde de carbone est egalement present; - etude de certains phenomenes lies a la corrosion: variations dimensionnelles des echantillons au cours des essais

  17. Irreversibility of Gas-Condensate Flow in Gas Cycling Projects: Kinetically Stable Saturation Patterns Irréversibilité des écoulements de gaz à condensat dans les projets de recyclage de gaz : profils stationnaires de saturation

    Directory of Open Access Journals (Sweden)

    Mitlin V.

    2006-12-01

    Full Text Available The dynamics of a two-phase multicomponent reservoir system which is approaching the steady-state flow regime are studied. First, the compositional model is analyzed in the linear approximation, for the case of a small initial deviation from the steady-state regime. An analytical expression is obtained for the characteristic relaxation time. Next, numerical simulations are performed for situations where there is a substantial deviation from the steady-state regime. The linear injection of an enriched gas into a gas-condensate reservoir, followed by the extraction regime, is simulated. It is shown that the change in phase compositions and pressure on the way to equilibrium proceeds with characteristic times of the order of the injection time. However, the change in the saturation and overall composition takes approximately 200 times longer than the injection time. Thus, the reservoir system manifests a spatially inhomogeneous saturation distribution for an abnormally long time. Similar kinetically stable patterns have been also discovered in the nonlinear dynamics of phase transitions, plasma, and thin films. The question of the existence of discontinuous steady states for this multicomponent flow is considered. In the case of a binary mixture, it is shown that such solutions do not exist. Cet article présente une étude de la dynamique d'un réservoir biphasique multiconstituant approchant le régime d'écoulement stationnaire. En premier lieu, nous procédons à une approximation linéaire du modèle compositionnel dans le cas des petites fluctuations autour du régime permanent. Une expression analytique est ainsi obtenue pour le temps caractéristique de transition. Des simulations numériques sont ensuite effectuées pour les déviations importantes par rapport au régime permanent. Nous avons ainsi pu étudier le déplacement linéaire d'un mélange gaz/condensat par un gaz enrichi suivi d'un régime de production. On montre alors que le

  18. Étude des équilibres thermodynamiques des réactions de gazéification en vue de l'optimisation du rapport vapeur/comburant injecté dans un gazogène souterrain Study of Thermodynamic Equilibria in Gasification Reactions So As to Optimise the Steam/Oxidizer Ratio Injected Into an Underground Gas Generator

    OpenAIRE

    Pirard J. P.

    2006-01-01

    Le but de cette étude est de déterminer sur la base des équilibres thermodynamiques des réactions de gazéification le rapport vapeur/comburant à injecter dans un gazogène fonctionnant sous pression pour optimaliser les compositions, les pouvoirs calorifiques, les rendements de gazéification et la consommation d'agent gazéifiant. The aim of this study is to determine, on the basis of the thermodynamic equilibria of gazification reactions, the steam/oxidizer ratio to be injected into a gas g...

  19. Fission gas pressure build-up and fast-breeder economy; Accumulation de la pression des gaz de fission et economie des reacteurs surgenerateurs a neutrons rapides; Nakoplenie davleniya gazov produktov deleniya i ehkonomika reaktorov-razmnozhitelej na bystrykh nejtronakh; Aumento de la presion de los gases de fision y economia de los reactores reproductores rapidos

    Energy Technology Data Exchange (ETDEWEB)

    Engelmann, P [Kernforschungszentrum, Karlsruhe (Germany)

    1962-03-15

    Fuel-cycle costs and doubling time of fast-breeder reactors are strongly affected by the fuel-burn-up obtainable. Use of oxide or carbide fuel offers the possibility of reaching a burn-up of 100 000 MWd/t. In fuel-clad elements, a limiting factor is the fission-gas-pressure build-up. At the high burn-up considered, an appreciable fraction of the fission gases gets into the pores and thus contributes to the pressure on the can. Starting from the known fission-product yields and decay chains, gas production and pressure build-up have been calculated. Three physical models have been employed in calculating the pressure acting upon the can : the gas is contained either in interconnected pores, in separate pores, or in a central hole. The pressure-dependence upon free volume (fuel density) and temperature will be discussed. Cans made of high-strength materials as Ineonel-X and molybdenum could stand the fission-gas pressure at operating temperatures. Unfortunately, these materials have higher absorption cross-sections than stainless steel. Results of a multi-group calculation are given, showing the effect of using these can materials and of decreasing the fuel density on critical mass and breeding ratio in small and medium-size breeders. (author) [French] Le cout du cycle de combustible et la periode de doublement des reacteurs surgenerateurs a neutrons rapides dependent etroitement du taux de combustion. En utilisant pour combustible un oxyde ou un carbure, on peut atteindre un taux de combustion de 100 000 MW j/t. Avec des combustibles gaines, l'accumulation de la pression des gaz de fission est un facteur limitatif. Pour le fort taux de combustion envisage, une fraction non negligeable des gaz de fission penetre dans les interstices et contribue ainsi a la pression sur la gaine. A partir des rendements en produits de fission et des chaines de desintegration connus, l'auteur a calcule la production de gaz et l'accumulation de pression. Pour calculer la pression

  20. ZEHİRLİ GAZ SALDIRILARINA KARŞI HALKIN BİLİNÇLENDİRİLMESİ VE EĞİTİMDEKİ YANSIMASI: GAZDAN KORUNMA DERSİ (1931-1940

    Directory of Open Access Journals (Sweden)

    Sena COŞĞUN KANDAL

    2016-10-01

    Full Text Available 19. yüzyılın ortalarına doğru gelişen kimya sanâyisi savaşların seyrini değiştirecek kadar önemli buluşlar ortaya çıkarmıştır. Kuşkusuz bu buluşların başında zehirli gazlar gelir. I. Dünya Savaşı boyunca kullanılan zehirli gazların yarattığı tehlike, savaş sonrasında kurulan Türkiye Cumhuriyeti’nde göz ardı edilmemiştir. Bu sebeple Maarif Vekâleti, Millî Savunma Vekâleti ve Kızılay işbirliği ile lise/muallim mektepleri ve ortaokul müfredât programlarına gazdan korunma dersi eklenmiş, öğrenciler ve memurlar için gazdan korunma kursları açılmış, yurtdışından, özellikle Almanya’dan uzmanlar getirilerek gerçekleşebilecek bir taarruzu en az zararla atlatmak için önlemler alınmıştır.Bu makalede “Gazdan Korunma Dersi” nin ortaya çıkışı ve gelişimi, Millî Talîm ve Terbiye Dâiresi ile Başbakanlık Cumhuriyet Arşivi belgeleri, dönemin gazeteleri ve ders kitaplarında bulunan bilgiler ışığında nitel araştırma yöntemlerinden doküman inceleme kullanılarak ortaya konulmuştur. Anahtar Kelimeler: Gaz Taarruzu, Gaz Saldırısı, Atatürk Dönemi Müfredât Programları, Kimya Dersi RAISE AWARENESS of PUBLIC AGAINST POISON GAS and its REFLECTIONS on EDUCATION: PROTECTION from GAS ATTACKS (1931-1940Abstract: The developing chemistry industry towards the middle of the 19th century provided significant inventions which had even the power to change course of events at war. Certainly, one of the main inventions was toxic gases. The toxic gases, which had been used during the World War I, and not neglected by the post-war government; Turkish Republic. For these reasons, by courtesy of The Board of Education, The Ministry of Defense and Red Crescent Society, “Protection from Gas Attacks” courses were added to the curriculum of high/teacher and mid school, gas protections courses were opened for students and officers, and from abroad; especially from Germany

  1. Simplified theory of gas-jet pumps and experimental verification; Theorie simplifiee des trompes a gaz et verification experimentale

    Energy Technology Data Exchange (ETDEWEB)

    Costes, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    With a view to using the gas-jet pump in the fuel-study loops of gas reactors, a theory is developed for an unidimensional mixer, applicable to the case of low compression ratios in the induced current. This theory makes it possible to optimize the diameter of the mixer if the pressure-drop coefficient {alpha} of the mixer is known with respect to the induced current. An experimental study has made it possible to define the geometry suitable for such pumps, and to provide a remarkably constant value of {alpha} for the economically advantageous designs; this makes it possible to define simply the geometry of the optimized pump as a function of the geometry of the circuit in use, and independently of the flow-rate conditions. (author) [French] Dans le but d'utiliser la pompe a jet (ou trompe) dans des boucles d'etude de combustible des piles a gaz, on etablit une theorie du melangeur unidimensionnel, applicable dans la cas des faibles rapports de compression dans le courant induit. Cette theorie permet l'optimisation du diametre de melangeur, moyennant la connaissance du coefficient {alpha} de pertes de charge de celui-ci, relativement au courant induit. Une recherche experimentale a permis de preciser la geometrie a adopter dans de telles pompes, et fourni pour {alpha} une valeur remarquablement constante dans les configurations economiquement interessantes, ce qui permet de definir simplement la geometrie de la pompe optimisee en fonction de la geometrie du circuit d'utilisation et independamment des conditions de debit. (auteur)

  2. Liberalization of energy markets, reorganization of work and collective mobilization in the company. The case of Gaz de Bordeaux

    International Nuclear Information System (INIS)

    Dif-Pradalier, M.

    2009-01-01

    Formerly in a monopolistic situation and running on a politico-administrative mode, Gaz de Bordeaux is a network industry now part of a competitive market. The present case study of this local public utility is meant to identify the nature of its modernisation and to measure its effects as well on the system of social regulations and professional identities, as on the capacities of action and forms of appropriation/resistance developed by the various categories of actors within the company. From a methodological point of view, we pledged ourselves with a combination of qualitative and quantitative approaches, aiming at articulating analysis of the work being done with that of collective action, both considered as linked realities. As work gains in intensity, in both senses of productive pressure (do more in less time and with fewer staff) and interest (given the need expressed by every person to come true by the reality of its work), the company appears as disrespectful of the quality of work possible and the capacities mobilized by individuals that modern management precisely contributed to develop. Faced with this reorganisation of work, labor unions struggle to grasp the issues at stake in modern employment relationships and translate individual complaints in renewed collective claims. Despite increasing individual withdrawal behaviours, working collectives recompose on new bases. We therefore revisit the origin of suffering at work; from its contemporary mutations, we present evidence for what we believe is one of its current major problems: the one at stake around what employees call a 'well done work', at the very moment when management is concerned with quality. (author)

  3. Ortaçağlardan 21. Yüzyıla Gazâlî’nin Kozmolojisinin Batılı Alımlanışı

    OpenAIRE

    GRIFFEL, Frank

    2011-01-01

    İslam teolojisinin konuları arasında özellikle Gazâlî’nin kozmolojisi Batı’da oldukça dikkat çekmiştir. Rönesans dönemi ilim adamları Gazâlî’nin Filozofların Tutarsızlığı (Tehâfütü’l-felâ- sife) adlı eserinin 17. meselesinde filozofların nedensellik teorilerine yönelttiği eleştirilere aşinaydılar. İslam teolojisine dair akademik araştırmaların başladığı 19. yüzyılın ilk yarısında ilim adamları, Gazâlî’nin sözkonusu meselede nedensel ilişkilerin varlığını reddettiği sonucuna ulaştılar. Gazâlî’...

  4. Plasmas pour valorisation totale ou partielle des gaz contenant de l'H2S Plasmas for Total Or Partial Upgrading of H2s Containing Gases

    Directory of Open Access Journals (Sweden)

    Czernichowski A.

    2006-12-01

    Full Text Available Des procédés par plasmas alternatifs au procédé Claus sont proposés pour produire de l'hydrogène et récupérer du soufre à partir des gaz contenant une forte teneur en H2S. Quand la teneur en H2S est moins importante, des techniques plasma peuvent également être utiles pour assister certains étages du procédé classique Claus ou réaliser ce procédé pour des gaz non conventionnels. Les tests allant jusqu'à l'échelle industrielle sont menés dans divers réacteurs à plasmas et les résultats encourageants rapportés de la littérature et de la recherche propre laissent envisager des prochaines applications. Plasma assisted processes are proposed to act as an alternative to the Claus process in order to recover hydrogen and sulphur from high H2S gases. For less concentrated gases plasma techniques may also be inserted into classical Claus plant or may allow treatment of non conventional gases. Up to industrial scale tests are performed using different plasma reactors. The literature-based results as well as our own ones make the future applications quite optimistic.

  5. Magnesium and uranium ignition in different gaseous atmospheres; Inflammabilite du magnesium et de l'uranium dans l'air et le gaz carbonique

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R; Baque, P; Leclercq, D [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Magnesium, uranium and some of their alloys burning temperatures have been systematically determined in an air or carbon dioxide atmosphere, either dry or wet. Two different ways of heating have been used: either continuously rising up the temperature, or heating to and then maintaining a constant temperature. The results are clearly different in the two cases. Besides, if moisture has little effect on the magnesium burning temperatures in air, it does lower them by about 130-140 deg. C in CO{sub 2}. The differences of sight between the burning of magnesium and uranium have been noticed; this leads to distinguish between an 'ignition' and an 'inflammation'. (author) [French] Les temperatures auxquelles apparait la combustion vive du magnesium, de l'uranium et certains de leurs alliages ont ete determinees systematiquement dans l'air et le gaz carbonique, soit secs, soit humidifies. On a mis en evidence l'influence du mode de chauffage sur les resultats: soit montee en temperature continue, soit stabilisation a partir d'une certaine temperature. En outre, si la presence d'humidite affecte peu les temperatures de combustion vive du magnesium dans l'air, elle les abaisse de 130 a 140 deg. C dans le gaz carbonique. Les differences d'aspect entre la combustion vive du magnesium et de l'uranium ont egalement ete remarquees, ce qui amene notamment a distinguer une 'ignition' d'une 'inflammation'. (auteur)

  6. World Gas Prospects: Which Role for the Middle East? Perspectives mondiales du gaz naturel : quel rôle pourrait jouer le Moyen-Orient ?

    Directory of Open Access Journals (Sweden)

    Chabrelie M. F.

    2006-12-01

    Full Text Available Since the early 1970s, the policies of energy diversification that have been implemented in the industrialized countries and in many developing countries have enabled natural gas to regularly increase its role in the world energy balance. Thus, during the past twenty years, natural gas recorded the highest growth rate among fossil fuels, and its share in the energy market has gradually risen from 18. 9% in 1975 to 23% in 1997. Today, thanks to favorable economic and environmental factors, natural gas has become the fuel of choice on many markets. Indeed, gas is blessed with a certain number of favorable assets (abundant reserves, flexibility, high-performance uses which give it a major role in all energy demand forecast scenarios. The most spectacular development will indisputably take place in the power generation sector. Endowed with a considerable gas potential, the Middle East will represent an essential source of supply for many industrialized countries and several gas export projects, either by LNG tanker or by pipelines are currently being contemplated. During the past decade, the contribution of natural gas to the energy mix also grew substantially in most Middle Eastern countries. The increase in gas demand should continue at a sustained rate, mainly driven by the power generation sector, petrochemicals and energy consumption by the hydrocarbons industry. These promising prospects for gas demand in most of the markets in the region might lead to the development of an intra-regional network. However, although opportunities exist, the region will have to meet many challenges in order to contribute more largely to the world gas balance in the years to come. de diversification énergétique mises en Suvre dans les pays industrialisés et dans de nombreux pays en voie de développement depuis le début des années 1970 ont permis au gaz naturel d'accroître régulièrement sa présence dans le bilan énergétique mondial. Ainsi, au cours des

  7. 2001-2003 ''public utility'' contract between the French government and Gaz de France; Contrat de ''service public'' 2001-2003 entre l'etat et Gaz de France

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    The ''public utility'' contract aims at specifying the actions of Gaz de France (GdF), the French gas utility, in terms of national development and public utility presence at the local scale. It extends and completes the 'contract of group' established between the government and GdF in the domain of quality of the services offered to clients, development of gas infrastructures and extension of gas supplies, and sustainable development. (J.S.)

  8. Ecoulements diphasiques gaz-liquide à poches et à bouchons en conduites Two-Phase Gas-Liquid Slug Flow in Pipes

    Directory of Open Access Journals (Sweden)

    Ferschneider G.

    2006-11-01

    Full Text Available Les écoulements diphasiques gaz-liquide ont été étudiés afin de contribuer à développer des modèles de calculs prédictifs des pertes de charge dans les conduites de production des bruts pétroliers. Les expériences nécessaires ont été réalisées sur la boucle diphasique de Boussens dans les conditions suivantes représentatives des conditions industrielles : diamètre 6 , longueur 120 m, disposition de la conduite horizontale ou faiblement ascendante, couple de fluide gaz naturel-huile légère. Le gradient de pression, le contenu global, et la distribution locale des phases ont été mesurés. Le traitement des équations de conservation phasique intégrées sur la section par différents types de moyennes a permis de développer un modèle cellulaire qui inclue un nombre limité d'équations constitutives nécessaires à sa fermeture. Ce modèle prédétermine convenablement le gradient de pression, le contenu gaz global et la longueur des poches et des bouchons. Two-phase gas-liquid flows were analyzed so as to develop models for prediction of pressure drops in crude-oil production lines. The experiments were performed on the two-phase loop at Boussens under the following representative industrial conditions: 6 diameter, 120 m length, horizontal or slightly rising pipe, couple of fluids natural gas and light oil. The pressure gradient, average content and local phase distribution were measured. Conservation phase equations integrated along the cross-section were processed by different time-averaged operators so as to develop a cellular model including a limited number of constitutive equations required for its closure. This model suitably predetermines the pressure gradient, the average gas content and the length of gas and liquid slug.

  9. Detection of high energy gamma radiations with liquid rare gases as scintillators; Detection des rayonnements Gamma de grande energie avec les gaz rares liquides comme scintillateurs

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Phan Xuan

    1965-11-25

    This research thesis reports the study of a sensor based on a liquid scintillator for the detection of high energy (10 to 30 MeV) gamma radiations. The scintillator is a liquefied argon or xenon rare gas. The author first studies the process of energy transfer from the particle to the sensing medium. He addresses the different involved elements and phenomena: electromagnetic radiations (Compton Effect, photoelectric effect, pair production, and total gamma absorption), charged particles (braking radiation, collisions) and application to gamma spectrometry. He describes and discusses the scintillation mechanisms (scintillation of organic and inorganic materials), the general characteristics of scintillators (impurities, converters), and then reports the practical realisation of the sensor. Results are presented and discussed [French] Dans ce travail, nous nous proposons d'etudier une technique. Il s'agit d'un detecteur a scintillateur liquide pour la detection des rayonnements gamma energiques (10 a 30 MeV). Le scintillateur utilise est un gaz rare liquefie argon ou xenon. Nous examinerons d'abord les processus de transfert de l'energie de la particule au milieu detecteur puis les mecanismes de scintillation en general pour pouvoir exploiter au mieux les phenomenes favorables. Nous presenterons ensuite la realisation pratique du detecteur. Ses qualites (et defauts) trouveront leur place dans la fin de ce memoire. Bien qu'a l'heure actuelle, par la methode de Kyropoulos, on puisse faire pousser des gros cristaux d'iodure de sodium, l'utilisation des 'gaz rares' liquefies comme scintillateurs est, grace a la brievete de la scintillation, tres utile lorsqu'on recherche un fort taux de comptage (jusqu'a 10 impulsions par seconde) ou lorsqu'on veut resoudre certains problemes de coincidence. Les cristaux NaI(Tl) de grandes dimensions sont d'un montage facile mais leur manipulation requiert beaucoup de precautions du fait qu'ils supportent tres mal les chocs thermiques

  10. La formation de l'oxyde azotique dans les flammes de diffusion de gaz naturel Nitrogen. Oxyde Formation in Natural-Gas Diffusion Flams

    Directory of Open Access Journals (Sweden)

    Portrait L. M.

    2006-11-01

    Full Text Available L'étude de la formation de l'oxyde azotique dans des flammes de diffusion de ga naturel est effectuée depuis deux ans sur le four expérimental du Groupe d'Etude des Flammes de Gaz Naturel situé à Toulouse. Un certain nombre de variables ont été explorées : type de flamme, excès d'air, préchauffage de l'air, teneur en oxygène du comburant, puissance calorifique, et débit de moment cinétique. L'étude a mis en évidence une corrélation générale, quelle que soit la variable considérée, entre la quantité maximale d'oxyde d'azote formé et la température maximale de la flamme. Certains des résultats précédents ont été exploités à l'Institut Français du Pétrole, en vue d'établir une équation de vitesse de formation de NO applicable aux flammes axiales de diffusion de gaz naturel. Les calculs s'appuient sur les connaissances obtenues lors de l'étude cinétique de formation de NO effectuée au Laboratoire d'Aérothermique Fondamentale. Les résultats du calcul théorique confirment ceux de l'étude sur le four expérimental en ce qui concerne l'influence prépondérante de la température sur la formation de l'oxyde azotique. Par ailleurs, le calcul théorique retrouve bien les résultats obtenus lors de l'étude fondamentale, selon lesquels la cinétique de formation de NO évolue le long de la flamme depuis le front de flamme jusqu'aux gaz brûlés. La généralisation à un grand nombre de flammes de l'équation cinétique expérimentale obtenue nécessite maintenant de prendre en compte certains phénomènes de diffusion négligés jusqu'à présent. Research on the formation of nitrogen oxide in natural-gas diffusion flammes has been going on for two years in the experimental furnace of the Groupe d'Etude des Flammes de Gaz Naturel located in Toulouse. Different variables have been investigoted such as type of flamme, air excess, air preheating, oxygen content in the oxidant, heating power and kinetic moment output

  11. Spatial flux instabilities, and their control in the graphite gas power reactors; Les instabilites spatiales du flux et leur controle dans les reacteurs de puissance graphite-gaz

    Energy Technology Data Exchange (ETDEWEB)

    Cailly, J L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Radial-azimuthal and axial spatial flux instabilities in graphite-gas reactors are studied by means of an analytical approach. Results are checked with those which are given by two dimensional (r, z and r, {theta}) kinetic models programmed for an IBM 7094 computer. At least, conclusions on the control of instabilities obtained from these models are reported. (author) [French] Les instabilites spatiales du flux dans les reacteurs graphite-gaz, radiales et azimutales d'une part, axiales d'autre part, sont etudiees au moyen d'une formulation analytique. Les resultats sont confrontes avec ceux que fournissent des modeles cinetiques a deux dimensions (r, z et r, {theta}) programmes sur IBM 7094. On donne enfin les conclusions relatives au controle de ces instabilites que ces modeles ont permis de degager. (auteur)

  12. Apparatus for studying the diffusion of rare gases in stainless steel; Appareil pour etude de la diffusion des gaz rares dans l'acier inoxydable

    Energy Technology Data Exchange (ETDEWEB)

    Stohr, J A; Alfille, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    This apparatus enables measurements to be carried out on the diffusion of gaseous fission products and of gases in general across thin metallic walls at high temperatures. This work was initially intended to solve the problems involved in systems for detecting the rupture of a fuel element can (D.R.G.) by the diffusion of fission products through the cans at high temperatures. The extension of the work to other fields is envisaged. (author) [French] Cet appareil permet d'effectuer des mesures sur la diffusion des produits de fission gazeux, et des gaz en general, au travers de parois metalliques minces a haute temperature. Au depart, ce procede devait contribuer a resoudre les problemes poses aux systemes detecteurs de rupture de gaine (D.R.G.), par la diffusion des produits de fission au travers des gaines de cartouches a haute temperature. Son extension a d'autres etudes est envisagee. (auteur)

  13. The analysis on of the effect of urea, iron sulfate and vermicompost fertilizers on the growth characteristics and yield of sunflower (Helianthus annuus L. The city Darreh Gaz

    Directory of Open Access Journals (Sweden)

    mahdiyeh zomorrodi

    2015-12-01

    Full Text Available To study the effect of vermicompost and urea and iron sulfate fertilizers on the growth characteristics and yield of sunflower seed (Helianthus annuus L. an pediment was conducted in Darreh Gaz located in Khorasan Razavi province in 2012. Factorial experiment in a randomized complete block design with three factors and three repetition. In this experiment three levels of urea (50; 150 and 250 kg per hectare as the first factor and two level of vermicompost (7 tons per hectare consumption and non-consumption as the second factor and two iron sulfate (80 kilogram per hectare consumption and non- consumption were considered as the third factor. The results showed that the effect of urea × vermicompost treatment combination on stem height, head diameter, stem dry weight and yield was significantly at one percent probability level. The treatment combination of 250 kg. ha-1 × iron sulfate× vermicompost increased plant height, head diameter, petiole dry weight. Vermicompost × iron sulfate treatment combination on the dry weight’s leaf, petiole, stem and head were the highest significant (p≤0.01. The application of vermicompost × iron sulfate treatment combination resulted in the highest rate of stem diameter, leaf dry weight and stem the highest yield belonged to 250 kg.ha-1 × vermicompost. Iron sulfate use different amounts of urea fertilizer redact yield. The lowest yield of 250 kg.ha-1× iron sulfate was related to treatment combination. So it seems that the combined application of organic vermicompost fertilizer and urea and iron sulfate fertilizers on the growth and yield of sunflower Darreh Gaz can be effective in improving properties.

  14. Transport diphasique de gaz et de condensat. Aspects techniques et économiques Technical and Economic Aspects of Two-Phase Pipelining of Gas and Condensate

    Directory of Open Access Journals (Sweden)

    Bourgeois T.

    2006-11-01

    Full Text Available L'évacuation diphasique de la production d'un gisement de gaz à condensat présente des avantages importants, en particulier sur le plan économique. Les caractéristiques des écoulements diphasiques sont exposées, avec les conséquences principales sur la définition d'un schéma d'exploitation. Une comparaison économique est ensuite présentée, pour illustrer la réduction des investissements qui peut être apportée par l'évacuation diphasique de la production. Enfin, les recherches françaises sur les écoulements diphasiques dans les conduites pétrolières sont brièvement décrites, ainsi qu'un exemple de calcul sur une conduite de gaz à condensat en exploitation diphasique. The two-phase pipelining of a wet gas field production presents many advantages, especially from an economic point of view. The characteristics of two-phase flow are described, together with their main consequences on the operational scheme. Then an economic comparison is made to illustrate the reduction in investment costs that can by achieved with two-phase pipelining. Research in France on two-phase flow in gas and condensate pipelines is briefly described, and an example is given of the designing of a wet-gas pipeline currently being operated in the two-phase mode.

  15. Gasification in Petroleum Refinery of 21st Century La gazéification dans la raffinerie du pétrole du XXIe siècle

    Directory of Open Access Journals (Sweden)

    Furimsky E.

    2006-12-01

    goudrons, le coke et l'asphalte, résultant respectivement de la viscoréduction, de la carbonisation et du désasphaltage. Les résidus finaux peuvent être, à leur tour, convertis en produits utilisables comme l'hydrogène, la vapeur, l'électricité, l'ammoniac et des produits chimiques. Dans ce contexte, la gazéification est apparue comme la technologie de choix pour la valorisation des résidus en raison de ses meilleures performances. De même, les boues de raffinerie peuvent être cogazéifiées avec les résidus finaux et devenir alors des produits valorisables. Intégrée à la raffinerie de pétrole, la gazéification peut aider à résoudre les problèmes environnementaux liés à l'élimination des résidus et des boues. Les résultats économiques de la raffinerie peuvent également être améliorés. Les tendances de déréglementation du marché de l'énergie permettent aux raffineries de pétrole d'y pénétrer, soit toutes seules, soit en partenariat avec les fournisseurs d'utilités. Le potentiel de coproduction de produits chimiques et de vapeur avec l'électricité offre une souplesse de réaction permettant de répondre aux demandes du marché. L'intérêt de la technologie de la gazéification est commercialement démontré. Parmi d'autres, les gazéificateurs à lit entraîné sont les gazéificateurs de prédilection. Plusieurs projets commerciaux en Europe, en Asie et aux États-Unis font appel à un gazéificateur utilisant soit un système d'alimentation en suspension, soit un système d'alimentation par voie sèche.

  16. Gas and electric power opening of the markets. Reality, limits and paradoxes the position of the cogeneration; Gaz electricite ouverture des marches. Realite, limites et paradoxes place de la cogeneration

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    During these two days of the colloquium on gas and electric power market opening, industrial and french administration discussed about the new market deregulation impacts and the cogeneration position in this context. The position of EDF and Gaz De France, the european competition and the government policy are presented. These nineteen papers proposed an economic analysis and the state of the art of the situation. (A.L.B.)

  17. Realisation and tests of a compressed gas Cherenkov counter. Study of the pollution of a beam (1961); Realisation et essais d'un compteur cherenkov a gaz comprime etude de la pollution d'un faisceau (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Duboc, J; Banaigs, J; Detoeuf, J F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The realisation of a compressed as Cherenkov counter permits the study of the pollution of a beam of {pi} mesons with momentum varying from 220 to 11000 MeV/c. (authors) [French] La realisation d'un compteur Cherenkov a gaz sous pression permet l'etude de la pollution d'un faisceau de mesons {pi} d'impulsions comprise entre 220 et 1100 MeV/c. (auteurs)

  18. The compatibility of chromium-aluminium steels with high pressure carbon dioxid at intermediate- temperatures; Compatibilite des aciers au chrome-aluminium avec le gaz carbonique sous pression aux temperatures moyennes

    Energy Technology Data Exchange (ETDEWEB)

    Leclercq, D; Loriers, H; David, R; Darras, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    With a view to their use in the exchangers of nuclear reactors of the graphite-gas or heavy water-gas types, the behaviour of chromium-aluminium steels containing up to 7 per cent chromium and 1.5 per cent aluminium has been studied in the presence of high-pressure carbon dioxide at temperatures of between 400 and 700 deg. C. The two most interesting grades of steel (2 per cent Cr - 0.35 per cent Al - 0.35 per cent Mo and 7 per cent Cr - 1.5 per cent Al - 0.6 per cent Si) are still compatible with carbon dioxide up to 550 and 600 deg. C respectively. A hot dip aluminised coating considerably increases resistance to oxidation of the first grade and should make possible its use up to temperatures of at least 600 deg. C. (authors) [French] Dans l'optique de leur emploi dans les echangeurs de reacteurs nucleaires des filieres graphite-gaz ou eau lourde-gaz, le comportement en presence de gaz carbonique sous pression d'aciers au chrome-aluminium, contenant jusqu'a 7 pour cent de chrome et 1,5 pour cent d'aluminium a ete etudie entre 400 et 700 deg. C. Les deux nuances les plus interessantes (2 pour cent Cr - 0,35 pour cent Al - 0,35 pour cent Mo et 7 pour cent Cr - 1,5 pour cent Al - 0,6 pour cent Si) restent compatibles avec le gaz carbonique jusqu'a 550 et 600 deg. C respectivement. Un revetement d'aluminium, effectue par immersion dans un bain fondu, ameliore notablement la resistance a l'oxydation de la premiere et doit permettre son empioi jusqu'a 600 deg. C au moins. (auteurs)

  19. Depo Gazı Enerji Üretim Tesisi Baca Gazı Atık Isısının Seralarda Değerlendirilmesi: İstanbul Örneği / Utilization of Waste Heat in Energy Production Plant from Landfill Gas at Greenhouses – Case Study in Istanbul

    Directory of Open Access Journals (Sweden)

    Volkan Enç

    2012-12-01

    Full Text Available Evsel atık düzenli depolama sahaları kullanım ömrü dolduktan sonra yararlı kullanım alanları sınırlı sahalardır. Çoğunlukla yeşil alan olarak kullanılan bu yerler ekonomik ve çevresel anlamda atıl durumda bulunmaktadır. Depolama sahalarının İstanbul gibi arazi sıkıntısı çeken bir şehirde yararlı amaçlar için kullanılması elzemdir. Depolama sonrası sahalarda metan gazı oluşmakta ve farklı yöntemlerle kontrol altına alınmaktadır. Bu gazların toplanması, taşınması ve özel motorlarda yakılması ile elektrik enerjisi üretilmektedir. Tesislerde gazın yakılması, depo gazı içerisinde bulunan CH4 (metan gazının CO2’e indirgenmesini sağlayarak sera etkisini azaltmakta, elektrik enerjisi üreterek ekonomiye katkı sağlamaktadır. Çevresel ve ekonomik yarar göz önüne alındığında, depo gazından enerji üretim tesislerinde, enerji üretiminde mümkün olabilecek maksimum verime ulaşılmalıdır. Bu düşünce ile bakıldığında, depo gazı enerji üretim tesisinde oluşan atık ısının değerlendirilemeden atmosfere verilmesi önemli bir sorun olarak ortaya çıkmaktadır. Oldukça yüksek debi ve sıcaklığa sahip bu ısı, enerji bakımından önemli bir potansiyele sahiptir. Bu sıcaklıktaki ve debideki ısının değerlendirilmeden atmosfere verilmesi, çevreyi olumsuz etkilemesinin yanında ekonomik kayıplara yol açmaktadır. Seralarda mevsimlik çiçek üretimi, maliyeti yüksek bir faaliyettir. Maliyetlerin önemli bir kısmını sera ısıtılması ve gübre kullanımı oluşturmaktadır. Isıtma işlemi için Türkiye’nin büyük bir bölümünde kömür ve doğalgaz kullanılmaktadır. Kışın seraların ısıtılması için kullanılan fosil yakıtların hem maliyeti yüksek, hem de çevresel standardı düşüktür. Bu çalışma, İstanbul Kalkınma Ajansı (İSTKA tarafından desteklenen “Depo Gazı Enerji Üretim Tesisi Atık Isının ve Kompostun Seralarda

  20. Detection of radioactive gases in the CO{sub 2} cooling the reactors G 2 - G 3; Detection des gaz radioactifs dans le CO{sub 2} de refroidissement des piles G2 - G3

    Energy Technology Data Exchange (ETDEWEB)

    Pouthier, J; Rossi, J [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

    1968-07-01

    The carbon dioxide cooling the reactors G2 - G3 contains activation gases and fission gases. It is of interest to know their concentration, for example to be able to deduce rapidly the norms which would have to be applied in the case of an incident in the circuit. Gas-phase chromatography is applied daily for carrying out analyses. The chromatogram has separate peaks due to tritium, argon 41, krypton 85 and the 133 and 135 isotopes of xenon. By integrating each peak it is possible to calculate the specific activity of each product. The construction of an apparatus for carrying out continuous measurements is under consideration. (authors) [French] Le gaz carbonique, refroidissant les reacteurs G2 - G3, contient des gaz d'activation et des gaz de fission. Il est interessant de connaitre leur teneur par exemple pour etre en mesure de deduire rapidement les normes qu'il y aurait lieu d'appliquer en cas d'incidents sur le circuit. La methode de chromatographie en phase gazeuse est employee quotidiennement pour faire des analyses. Le chromatogramme se presente sous forme de pics distincts dus au tritium, a l'argon 41, au krypton 85 et aux isotopes 133 et 135 du xenon. L'integration de chaque pic permet de calculer l'activite specifique de chaque compose. Il est envisage de construire un appareil pour des mesures en continu. (auteurs)

  1. Gaz - almaz / Jekaterina Rodina

    Index Scriptorium Estoniae

    Rodina, Jekaterina

    2008-01-01

    Venemaa Energiapoliitika Instituudi arvutuste kohaselt võib maagaasi tootmise ja nõudluse vahe ulatuda 2010. aastaks 100 miljardi kuupmeetrini, Kui maagaasi tarned Eestisse ära jäävad, saab meie riik omal jõul hakkama kõige rohkem kuu aega. Vt. samas: Gaas arvudes

  2. Gas mission; Mission gaz

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This preliminary report analyses the desirable evolutions of gas transport tariffing and examines some questions relative to the opening of competition on the French gas market. The report is made of two documents: a synthesis of the previous report with some recommendations about the tariffing of gas transport, about the modalities of network access to third parties, and about the dissociation between transport and trade book-keeping activities. The second document is the progress report about the opening of the French gas market. The first part presents the European problem of competition in the gas supply and its consequences on the opening and operation of the French gas market. The second part presents some partial syntheses about each topic of the mission letter of the Ministry of Economics, Finances and Industry: future evolution of network access tariffs, critical analysis of contractual documents for gas transport and delivery, examination of auxiliary services linked with the access to the network (modulation, balancing, conversion), consideration about the processing of network congestions and denied accesses, analysis of the metering dissociation between the integrated activities of gas operators. Some documents are attached in appendixes: the mission letter from July 9, 2001, the detailed analysis of the new temporary tariffs of GdF and CFM, the offer of methane terminals access to third parties, the compatibility of a nodal tariffing with the presence of three transport operators (GdF, CFM and GSO), the contract-type for GdF supply, and the contract-type for GdF connection. (J.S.)

  3. Contribution to the study of the fission-gas release in metallic nuclear fuels; Contribution a l'etude du degagement des gaz de fission dans les combustibles nucleaires metalliques

    Energy Technology Data Exchange (ETDEWEB)

    Kryger, B [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-10-01

    In order to study the effect of an external pressure on the limitation of swelling due to fission-gas precipitation, some irradiations have been carried out at burn-ups of about 35.000 MWd/ton, and at average sample temperatures of 575 Celsius degrees, of non-alloyed uranium and uranium 8 per cent molybdenum gained in a thick stainless steel can. A cylindrical central hole allows a fuel swelling from 20 to 33 per cent according to the experiment. After irradiation, the uranium samples showed two types of can rupture: one is due to the fuel swelling, and the other, to the pressure of the fission gases, released through a network of microcracks. The cans of the uranium-molybdenum samples are all undamaged and it is shown that the gas release occurs by interconnection of the bubbles for swelling values higher than those obtained in the case of uranium. For each type of fuel, a swelling-fission gas release relationship is established. The results suggest that good performances with a metallic fuel intended for use in fast reactor conditions can be obtained. (author) [French] Afin d'etudier l'effet d'une pression exterieure sur la limitation du gonflement due a la precipitation des gaz de fission, on a irradie a des taux de combustion d'environ 35.000 MWj/t et a des temperatures moyennes de 575 degres des echantillons d'uranium non allie et d'uranium-molybdene 8 pour cent contenus dans une gaine en acier inoxydable epaisse. Un trou cylindrique central permet au combustible de gonfler librement de 20 a 33 pour cent suivant les cas. Apres irradiation les echantillons d'uranium presentent deux types de ruptures de gaine: l'une due au gonflement du combustible, l'autre a la pression des gaz degages, ce degagement des gaz etant provoque par un reseau de micro-fissures. Les gaines des echantillons d'alliage uranium-molybdene sont toutes intactes et l'on montre que le relachement des gaz opere par interconnexion des bulles pour des valeurs de gonflement plus elevees que dans

  4. Preparation and properties of carbonaceous products prepared by the cracking of natural gas; Fabrication et proprietes de corps carbones prepares par craquage de gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    Blum, P L; Bochirol, L; Rappeneau, J; Cornuault, P; Blanchard, R; Moreau, C [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-07-01

    Complete results are presented of tests recently carried out at the Grenoble Nuclear Research Centre in an attempt to transform natural gas (gas from Lacq), used as a source of pyrolytic carbon, into carbonaceous products with improved properties. Several methods have been studied: 1 - By using normal grade industrial graphite as support (density of about 1.50) products having densities of about 1.80 are obtained. Their open porosity (6 to 7 per cent) is lower than that of conventional graphites, and several of their characteristics are more or less equal to, or better than those obtained from a double impregnation witch pitch. 2 - The use as supporting material of the semi-products ('cooked') usually used for graphite production does not lead to satisfactory results. The main reasons for this are given. 3 - A new process, called 'BB5', has been developed. The starting materials here are powdered products (petrol coke or graphite) which are put into shape with the use of a binder which can be dispersed in water. The supports thus produced make it possible, because of their porous structure, to make the most of the densification produced by cracking natural gas below 1000 deg. C. The products obtained, which are made up of equal amounts approximately of the supporting material and of pyrocarbon can attain densities of over 1.90. Their very low open porosity can be reduced almost to zero and their impermeability is then excellent (k=10{sup -8} cm{sup 2}sec{sup -1}). They have also a remarkably high resistance to compression, values of 15 to 20 kg/mm{sup 2} being obtained for those carbons which have not undergone a final graphitization treatment. Some examples are given of possible nuclear applications of the materials produced in this manner. (authors) [French] On expose l'ensemble des essais effectues recemment au CEN-G pour preparer, a partir de gaz naturel (gaz de Lacq) comme source de carbone pyrolytique, des corps carbones de caracteristiques ameliorees

  5. Containment for Heavy-Water Gas-Cooled Reactors; Le Confinement des Reacteurs a Eau Lourde Refroidis par Gaz

    Energy Technology Data Exchange (ETDEWEB)

    Verstraete, P.; Lehmann, D.; Lafitte, R. [Bonard et Gardel, Ingenieurs-Conseils, Lausanne (Switzerland)

    1967-09-15

    par gaz sont passes en revue dans le but d'etablir les specifications des enceintes de confinement en fonction des conditions des sites disponibles en Suisse pour la construction de centrales nucleaires. Ces specifications sont etablies d'apres les taux de dose consideres comme admissibles pour les populations vivant aux environs de la centrale en cas d 'accident grave du reacteur, en se basant sur des conditions meteorologiques et demographiques representatives de la plupart des sites du pays. Differents modes de construction de l ' enceinte de confinement, prenant en consideration les conditions qui s'etablissent dans l'enceinte a la suite de l'accident maximal concevable du reacteur, sont consideres. Les enceintes etudiees sont les suivantes: beton precontraint; beton precontraint avec coupole d'acier; beton precontraint avec peau d' etancheite interieure en acier; acier avec ecran lateral en beton pour la protection contre les radiations; et double confinement. Le degre d'etancheite des enceintes etudiees a ete considere comme une caracteristique lie e au mode de construction particulier et non comme une valeur prescrite en vue de laquelle la construction devait etre adaptee. Les caracteristiques d'etancheite de chaque enceinte sont estimees et les prix de chaque construction ont ete determines sur la base de plans precis avec le concours de diverses entrepises specialisees. L'estimation de l'efficacite des differentes enceintes, sous l'an gle de la securite, a ete faite en prenant en consideration differentes procedures en cas d' accident parmi lesquelles on citera principalement le rejet atmospherique, au travers de filtres adequats, et la decontamination de l 'atmosphere de l 'enceinte par recyclage dans des batteries de filtres. Une dizaine de cas, correspondant a differentes combinaisons de modes de construction et procedures en cas d'accident, font l 'objet d'une comparaison tres detaillee qui a ete realisee grace a un programme pour ordinateur electronique

  6. Corrosion of magnesium and some magnesium alloys in gas cooled reactors; Corrosion du magnesium et de certains de ses alliages dans les piles refroidies par gaz

    Energy Technology Data Exchange (ETDEWEB)

    Caillat, R; Darras, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The results of corrosion tests on magnesium and some magnesium alloys (Mg-Zr and Mg-Zr-Zn) in moist air (like G1 reactor) and in CO{sub 2}: (like G2, G3, EDF1 reactors) are reported. The maximum temperature for exposure of magnesium to moist air without any risk of corrosion is 350 deg. C. Indeed, the oxidation rate follows a linear law above 350 deg. C although it reaches a constant level and keeps on very low under 350 deg. C. However, as far as corrosion is concerned this temperature limit can be raised up to 500 deg. C if moist air is very slightly charged with fluorinated compounds. Under pressure of CO{sub 2}, these three materials oxidate much more slowly even if 500 deg. C is reached. The higher is the temperature, the higher is the constant level of the weight increase and the quicker is reached this one. However, Mg-Zr alloy behaves quite better than pure magnesium and especially than Mg-Zr-Zn alloy. (author)Fren. [French] On expose essentiellement les resultats d'etudes sur la corrosion du magnesium et de certains de ses alliages (Mg-Zr et Mg-Zr-Zn) dans l'air humide (cas de la pile G1) et dans le gaz carbonique (cas des piles G2, G3, EDF1, etc...). La temperature limite d'exposition du magnesium dans l'air humide sans risque de corrosion se situe a 350 deg. C; en effet l'oxydation a un caractere lineaire au-dessus de cette temperature, alors qu'elle atteint un palier et reste tres limitee au-dessous de 350 deg. C. Du point de vue de la corrosion, cette temperature limite d'emploi peut cependant etre elevee jusqu'a 500 deg. C si l'on introduit dans l'air humide de tres faibles teneurs de composes fluores. Dans le gaz carbonique sous pression, l'oxydation est beaucoup plus faible, meme jusqu'a 50g. C pour les trois materiaux: l'augmentation de poids atteint un palier d'autant plus eleve et ceci d'autant plus rapidement que la temperature est elle-meme plus elevee. Cependant, l'alliage Mg-Zr se comporte nettement mieux que le magnesium pur et surtout que l

  7. Corrosion of magnesium and some magnesium alloys in gas cooled reactors; Corrosion du magnesium et de certains de ses alliages dans les piles refroidies par gaz

    Energy Technology Data Exchange (ETDEWEB)

    Caillat, R.; Darras, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The results of corrosion tests on magnesium and some magnesium alloys (Mg-Zr and Mg-Zr-Zn) in moist air (like G1 reactor) and in CO{sub 2}: (like G2, G3, EDF1 reactors) are reported. The maximum temperature for exposure of magnesium to moist air without any risk of corrosion is 350 deg. C. Indeed, the oxidation rate follows a linear law above 350 deg. C although it reaches a constant level and keeps on very low under 350 deg. C. However, as far as corrosion is concerned this temperature limit can be raised up to 500 deg. C if moist air is very slightly charged with fluorinated compounds. Under pressure of CO{sub 2}, these three materials oxidate much more slowly even if 500 deg. C is reached. The higher is the temperature, the higher is the constant level of the weight increase and the quicker is reached this one. However, Mg-Zr alloy behaves quite better than pure magnesium and especially than Mg-Zr-Zn alloy. (author)Fren. [French] On expose essentiellement les resultats d'etudes sur la corrosion du magnesium et de certains de ses alliages (Mg-Zr et Mg-Zr-Zn) dans l'air humide (cas de la pile G1) et dans le gaz carbonique (cas des piles G2, G3, EDF1, etc...). La temperature limite d'exposition du magnesium dans l'air humide sans risque de corrosion se situe a 350 deg. C; en effet l'oxydation a un caractere lineaire au-dessus de cette temperature, alors qu'elle atteint un palier et reste tres limitee au-dessous de 350 deg. C. Du point de vue de la corrosion, cette temperature limite d'emploi peut cependant etre elevee jusqu'a 500 deg. C si l'on introduit dans l'air humide de tres faibles teneurs de composes fluores. Dans le gaz carbonique sous pression, l'oxydation est beaucoup plus faible, meme jusqu'a 50g. C pour les trois materiaux: l'augmentation de poids atteint un palier d'autant plus eleve et ceci d'autant plus rapidement que la temperature est elle-meme plus elevee. Cependant, l

  8. CO{sub 2} direct cycles suitable for AGR type reactors; Cycles directs de gaz carbonique applicables aux reacteurs du genre AGR

    Energy Technology Data Exchange (ETDEWEB)

    Maillet, E [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1967-10-01

    The perspectives given by the gas turbines under pressure, to build simple nuclear power plants and acieving significantly high yield, are specified. The CO{sub 2} is characterised by by good efficiency under moderate temperature (500 to 750 Celsius degrees), compactness and the simpleness of machines and the safe exploitation (supply, storage, relief cooling, thermosyphon). The revision of thermal properties of the CO{sub 2} and loss elements show that several direct cycles would fit in particular to the AGR type reactors. Cycles that would diverge a little from classical models and able to lead to power and heat generation can lead by simple means to the best results. Several satisfying solutions present for the starting up, the power regulation and the stopping. The nuclear power plant components and the functioning safety are equally considered in the present report. The conclusions stimulate the studies and realizations of carbon dioxide gas turbines in when approprite. [French] Les perspectives offertes par la turbine a gaz sous pression, pour construire des centrales nucleaires simples et de rendement progressivement eleve, se precisent actuellement. le CO{sub 2} se distingue par sa bonne efficacite a temperature moderee (500 a 750 degres celsius), la compacite et la simplicite des machines, et la surete qu'il apporte a l'exploitation ( approvisionnement, stockage, refroidissement de secours, thermosiphon). La revision des proprietes thermophysiques du CO{sub 2} et des elements de pertes montre que divers cycles directs conviendraient en particulier aux reacteurs agr ou derives. Des cycles s'ecartant peu des modeles classiques, et se pretant ulterieurement a la production simultanee d'electricite et de chaleur, peuvent conduire par des moyens simples aux meilleurs resultats d'ensemble. Plusieurs solutions satisfaisantes se presentent pour le demarrage, le reglage de la puissance et l'arret. Les composants de la centrale et la surete de fonctionnement sont

  9. Étude des équilibres thermodynamiques des réactions de gazéification en vue de l'optimisation du rapport vapeur/comburant injecté dans un gazogène souterrain Study of Thermodynamic Equilibria in Gasification Reactions So As to Optimise the Steam/Oxidizer Ratio Injected Into an Underground Gas Generator

    Directory of Open Access Journals (Sweden)

    Pirard J. P.

    2006-11-01

    Full Text Available Le but de cette étude est de déterminer sur la base des équilibres thermodynamiques des réactions de gazéification le rapport vapeur/comburant à injecter dans un gazogène fonctionnant sous pression pour optimaliser les compositions, les pouvoirs calorifiques, les rendements de gazéification et la consommation d'agent gazéifiant. The aim of this study is to determine, on the basis of the thermodynamic equilibria of gazification reactions, the steam/oxidizer ratio to be injected into a gas generator operating under pressure so as to optimize the compositions, the heating values, the gasification efficiencies and the consumption of gasifying agent.

  10. Evolution of periodicity in periodical cicadas.

    Science.gov (United States)

    Ito, Hiromu; Kakishima, Satoshi; Uehara, Takashi; Morita, Satoru; Koyama, Takuya; Sota, Teiji; Cooley, John R; Yoshimura, Jin

    2015-09-14

    Periodical cicadas (Magicicada spp.) in the USA are famous for their unique prime-numbered life cycles of 13 and 17 years and their nearly perfectly synchronized mass emergences. Because almost all known species of cicada are non-periodical, periodicity is assumed to be a derived state. A leading hypothesis for the evolution of periodicity in Magicicada implicates the decline in average temperature during glacial periods. During the evolution of periodicity, the determinant of maturation in ancestral cicadas is hypothesized to have switched from size dependence to time (period) dependence. The selection for the prime-numbered cycles should have taken place only after the fixation of periodicity. Here, we build an individual-based model of cicadas under conditions of climatic cooling to explore the fixation of periodicity. In our model, under cold environments, extremely long juvenile stages lead to extremely low adult densities, limiting mating opportunities and favouring the evolution of synchronized emergence. Our results indicate that these changes, which were triggered by glacial cooling, could have led to the fixation of periodicity in the non-periodical ancestors.

  11. Epidemiological Surveillance at Electricite de France and Gaz de France: Health Assessment of Nuclear Power Plant Employers between 1993 and 1998

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, A.; Gros, H.; Carrier, E.; Labon, G.

    2004-07-01

    Because the 17,500 employees working in nuclear power plants at Electricite de France, the national power company, may be exposed to a wide variety of industrial hazards, the health insurance department of the company has set up an epidemiologic surveillance programme for them. This descriptive, cross-sectional,and exhaustive study examined sick-leaves, mortality and cancer incidence to assess the health of the employees working from 1993 through 1998. The analysis comparing the employees in nuclear power plants, considered exposed, to the rest of the personnel of Electricite de France-Gaz de France, the non-exposed (125,000 persons) showed that globally, the employees in the nuclear sector appeared to have fewer health problems than the other company employees. This was true regardless of age and especially for men, operating employees, and supervisory employees. Nonetheless three points must be noted: non-work accidents generated a non-significant excess of absenteeism and mortality among these employees, especially among management and supervisory personnel; suicides affected supervisors in particular; and an excess of primary malignant brain tumors affected both mortality (RR{sub 1}.96, NS) and incidence, especially among operating employees (RR=2.87, 95% CL=(1.00-8.43)). No excess of malignant blood disease was observed. (Author) 38 refs.

  12. Preparation and characterization of mechanically alloyed AB3-type based material LaMg2Ni5Al4 and its solid-gaz hydrogen storage reaction

    Science.gov (United States)

    Jaafar, Hassen; Aymard, Luc; Dachraoui, Walid; Demortière, Arnaud; Abdellaoui, Mohieddine

    2018-04-01

    We developed in the present paper the synthesis of a new AB3-type compound LaMg2Ni5Al4 by mechanical alloying (MA) process. ​​X-ray diffraction analysis (XRD) was used to determine the structural properties and the phase evolution of the powder mixtures. Two different synthesis pathways have been investigated. The first starting from elemental metals and the second from a mixture of two binary compounds LaNi5 (CaCu5-type structure, P6/mmm space group) and Al(Mg) solid solution (cubic Fm-3 m space group). The results show multiphase alloys which contain LaMg2Ni5Al4 main phase with hexagonal PuNi3-type structure (R-3 m space group). Rietveld analysis shows that using a planetary ball mill, we obtain a good yield of LaMg2Ni5Al4 compound after 5 h of mechanical alloying for both synthesis pathways. TEM analysis confirmed XRD results. SEM-EDX analysis of the final product was in agreement with the nominal chemical formula. A setup of possible solid-gaz hydrogenation reaction will be described so far at the end of this work. Electrochemical results demonstrate evidence on hydrogen absorption in the AB3 material and the discharge capacity was equal to 5.9 H/f.u.

  13. Oxidation of ordinary steels or alloys heated in carbon dioxide under pressure; Oxydation d'aciers ordinaires ou allies chauffes dans le gaz carbonique sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Leclercq, D; Chevilliard, C; Darras, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Selection tests were carried out on commercial steels from the viewpoint of their resistance to oxidation in carbon dioxide, under 25 atmospheres pressure, between 350 and 600 deg. C. Comparative curve of oxidation kinetics were obtained, from which the influence of various additive elements can be found; small amounts of aluminium particularly seem to be favourable in the case of only slightly alloyed steels. (author) [French] Des essais de selection d'aciers commerciaux ont ete effectues quant a leur resistance a l'oxydation dans le gaz carbonique, sous pression de 25 atmospheres, ente 350 et 600 deg. C. Des courbes comparatives de cinetique d'oxydation ont ete obtenues, ce qui permet de degager l'influence de divers elements d'addition; de faibles teneurs en aluminium apparaissent notamment favorables dans le cas des aciers peu allies. L'acier inoxydable 18-8 a egalement ete etudie, notamment sous forme de tubes minces. Son comportement est bon jusqu'au moins 600 deg. C dans ces conditions. (auteur)

  14. Epidemiological Surveillance at Electricite de France and Gaz de France: Health Assessment of Nuclear Power Plant Employers between 1993 and 1998

    International Nuclear Information System (INIS)

    Chevalier, A.; Gros, H.; Carrier, E.; Labon, G.

    2004-01-01

    Because the 17,500 employees working in nuclear power plants at Electricite de France, the national power company, may be exposed to a wide variety of industrial hazards, the health insurance department of the company has set up an epidemiologic surveillance programme for them. This descriptive, cross-sectional,and exhaustive study examined sick-leaves, mortality and cancer incidence to assess the health of the employees working from 1993 through 1998. The analysis comparing the employees in nuclear power plants, considered exposed, to the rest of the personnel of Electricite de France-Gaz de France, the non-exposed (125,000 persons) showed that globally, the employees in the nuclear sector appeared to have fewer health problems than the other company employees. This was true regardless of age and especially for men, operating employees, and supervisory employees. Nonetheless three points must be noted: non-work accidents generated a non-significant excess of absenteeism and mortality among these employees, especially among management and supervisory personnel; suicides affected supervisors in particular; and an excess of primary malignant brain tumors affected both mortality (RR 1 .96, NS) and incidence, especially among operating employees (RR=2.87, 95% CL=(1.00-8.43)). No excess of malignant blood disease was observed. (Author) 38 refs

  15. Cellular properties of slug flow in vertical co-current gas-liquid flow: slug-churn transition; Caracteristiques cellulaires du regime a poches en ecoulement gaz-liquide co-courant vertical. Transition vers le regime destructure

    Energy Technology Data Exchange (ETDEWEB)

    Lusseyran, Francois

    1990-12-13

    This research thesis reports the study and description of the structure of a slug flow regime in a co-current vertical cylindrical duct, and the characterization and prediction of its transition towards a slug-churn (de-structured) regime. Flow physical mechanisms highlighted by the measurement of two important dynamics variables (wall friction and thickness of liquid films) are related to hypotheses of cellular models. The author first proposes an overview of slug flow regimes: theoretical steady and one-dimensional analysis, mass assessment equations of cellular models, application to the assessment of the flow rate and of the thickness of the film surrounding the gas slug. In the second part, the author addresses the slug flow regime transition towards the slug-churn regime: assessment of the evolution of flow dynamic properties, use of average wall friction analysis to obtain a relevant transition criterion. The third part presents experimental conditions, and measurement methods: conductometry for thickness measurement, polarography for wall friction measurement, and gas phase detection by using an optic barrier or optic fibres [French] Les ecoulements gaz-liquide en conduite verticale presentent quatre configurations ou regimes d'ecoulement. Ce travail porte sur le regime a poches et sur la transition vers la configuration qui lui succede: le regime destructure (churn flow). Les mesures sont effectuees a 200D du point d'injection du gaz, dans une conduite de 12.2 mm de diametre et pour le couple de fluides eau-azote. Les deux principales grandeurs mesurees en fonction des flux d'entree sont: le frottement parietal instantane (methode electrochimique) et l'epaisseur de film instantanee (methode conductimetrique). Une detection optique simultanee de la presence des phases permet un traitement conditionnel de la base de donnees. Les caracteristiques de la cellule moyenne representative de chaque point de fonctionnement en sont deduites: longueur de la cellule

  16. Economical and geopolitical aspects bond to the foreseen development of the natural gas in an open market; Aspects economiques et geopolitiques lies au developpement prevu du gaz naturel dans un marche ouvert

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-12-15

    For the first time in 2000, the part of natural gas is equal to those of coal in the world energy accounting. The economy and the geo-policy of this developing energy is analyzed, showing an economy dominated by the transport costs, the specificity of the european sector and the opening market since 1980. The european market opening incertitudes and opportunities are detailed. In conclusion the Gaz De France role in the european energy pole and the new regulations are discussed. (A.L.B.)

  17. The gas market opens out to competition: how will the French system of distributions evolve?; Ouverture a la concurrence du marche du gaz: quelle evolution pour le systeme francais des concessions de distribution?

    Energy Technology Data Exchange (ETDEWEB)

    Carbonnier, R. [Strasbourg-3 Universite, Robert Schuman, 67 (France)]|[Strasbourg-1 Univ. Louis Pasteur, 67 (France)

    1998-10-01

    Th public distribution of natural gas in France is organised around a system of franchises allocated by the communes to a unique designated distributor (Gaz de France in most cases). This system, which was recently eased by a legislative provision, seems to have an uncertain future faced with the opening of competition that is encouraged by the European authorities and with the demands of some local communities which would like to lay a greater role in the future organisational plan for gas. This article looks at the possible evolutions, from the reactivation of franchises to their complete disappearance. (author)

  18. Risk Analysis of Flare Flame-out Condition in a Gas Process Facility Analyse des risques des conditions d’extinction de torche au sein d’une installation de traitement de gaz

    Directory of Open Access Journals (Sweden)

    Zadakbar O.

    2011-02-01

    Full Text Available Flaring is a common method of disposal of flammable waste gases in the downstream industries. Flare flame out (flame lift-off or blow-outs often occurs causing toxic vapors to discharge. The toxic gases released may have hazardous effects on the surrounding environment. To study the effect of inhalation exposure of these toxic gases on human health, the four steps of the EPA (Environmental Protection Agency framework with the field data to quantify the cancer and non-cancer health risks are integrated in this paper. As a part of exposure assessment, gas dispersion modeling using AERMOD and UDM-PHAST is applied in two different conditions of normal flaring and flare flame out during a particular climate condition in Khangiran region. Recommendations to avoid flare flame out conditions are also presented here. Le torchage est un procédé courant d’élimination des gaz résiduaires inflammables dans les industries de traitement. L’extinction de la torche (par décollage ou soufflage de flamme provoque souvent une émission de vapeurs toxiques. Ces gaz toxiques libérés peuvent présenter des effets dangereux sur le milieu environnant. Pour étudier l’effet d’une exposition par inhalation de ces gaz toxiques sur la santé, cet article croise les quatre étapes de la démarche de l’EPA (Environmental Protection Agency, Agence de protection de l’environnement avec les données d’exploitation afin de quantifier le risque sanitaire cancérologique et non cancérologique. Dans le cadre de l’estimation d’exposition, une modélisation de dispersion des gaz utilisant AERMOD et UDM-PHAST est évaluée dans deux configurations différentes de torchage normal et d’extinction de torche à l’occasion de conditions climatiques particulières dans la région du Khangiran. L’article propose également des recommandations destinées à éviter les conditions d’une extinction de flamme de torche.

  19. Possibilités de contribution de la gazéification Lurgi à notre approvisionnement énergétique futur Potential Contribution of Lurgi Gasification to Our Future Energy Supplies

    Directory of Open Access Journals (Sweden)

    Eckert G.

    2006-11-01

    Full Text Available Pour la valorisation du charbon, la gazéification est une possibilité immédiatement utilisable et industriellement éprouvée, qui présente l'avantage de permettre la production des formes d'énergie secondaire, auxquelles nous sommes habitués. Indépendamment du produit final, une unité de conversion du charbon est toujours constituée d'étapes de transformation successives, mettant en oeuvre des procédés adaptés, parmi lesquels la gazéification de charbon proprement dite constitue la première étape qui n'est cependant qu'une opération parmi d'autres. Le traitement des gaz et la séparation des produits secondaires sont mis en oeuvre également et sont importants dans l'ensemble du complexe de traitement. Dans la communication présentée, trois possibilités différentes sont évoquées : - production de gaz de chauffage de différents pouvoirs calorifiques ; - production de méthanol et transformation éventuelle de celui-ci en essence ; - production d'hydrocarbures par la synthèse de Fischer-Tropsch. Une approche économique générale dégage une idée d'ensemble sur la situation et l'intérêt des techniques de conversion du charbon à l'heure actuelle. For the upgrading of coal, gasification is an immediately available and industrially well-proven possibility which has the advantage of making it possible to produce the types of secondary energy to which we have become accustomed. Independently of the end product, a coal conversion plant always consists of successive transformation steps making use of suitable processes, among which coal gasification itself is the first such step, although being only one operation among others. Gas processing and secondary products separation are also implemented and are important in the overall processing complex. This article brings out three different possibilities: (a production of fuel gas with different heating values; (b production of methanol and eventual transformation into gasoline

  20. A study on the isotope effects in the reduction of carbon dioxide by zinc; Etude des effets isotopiques dans la reduction du gaz carbonique par le zinc

    Energy Technology Data Exchange (ETDEWEB)

    Senegacnik, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-06-15

    We have determined the isotope effects which occur in the reduction of carbon dioxide by zinc. It has been shown that in the case of irreversible surface reactions, Bernstein's equation which permits the calculation of the fractionation factor is still valid. These experimental factors are in good agreement with those obtained by calculating the partition functions of the adsorbed activated complexes. In the reaction mechanism used, the model of the activated complex corresponds to the dissociation of one of the carbon oxygen bonds CO{sub 2} {yields} CO + O. Perturbations arising from the slight reversibility of the reaction Zn + CO{sub 2} {r_reversible} ZnO + CO on the isotope effects on the carbon and oxygen atoms have also been calculated. (author) [French] Nous avons etudie les effets isotopiques qui ont lieu dans la reduction du gaz carbonique par le zinc. La validite de l'equation de Bernstein qui permet de calculer le facteur de fractionnement a ete demontree pour le cas d'une reaction irreversible de surface. Ces facteurs de fractionnement experimentaux sont en bon accord avec ceux obtenus par le calcul des fonctions de partition isotopiques des complexes actives adsorbes. Dans le mecanisme de reaction utilise, le modele du complexe active correspond a la dissociation d'une des liaisons carbone oxygene CO{sub 2} {yields} CO + O. Les effets perturbateurs de la reversibilite de la reduction Zn + CO{sub 2} {r_reversible} ZnO + CO sur les effets isotopiques du carbone et ceux de l'oxygene ont ete egalement evalues. (auteur)

  1. Enjeux juridiques du contrôle des émissions personnelles de gaz à effet de serre par un dispositif de carte carbone

    Directory of Open Access Journals (Sweden)

    Sandrine Rousseaux

    2011-02-01

    Full Text Available La carte carbone individuelle est un dispositif innovant, qui permet d’impliquer les particuliers dans la lutte face au changement climatique. Ce dispositif consiste à limiter leurs émissions de gaz à effet de serre, ce qui suppose de suivre leur consommation de certains produits et services. Ce mode de contrôle des émissions personnelles soulève parfois des controverses, la carte carbone pouvant être perçue comme un instrument de rationnement potentiellement liberticide. Ces deux aspects sont discutés sur la base d’une analyse comparative de la conception et des modalités de mise en œuvre des différents dispositifs de carte carbone, établis ou envisagés en Europe et aux États-Unis. Il en ressort que les controverses ne sont pas réellement fondées.The individual carbon card is an innovative mechanism that helps involve individuals in the fight against climate change. It consists in limiting their greenhouse gas emissions, which requires monitoring a part of their goods and services consumption. This method of personal emissions control is much debated since the carbon card may be perceived as a rationing tool and raises civil liberty issues. Both of these controversial aspects are discussed on the basis of a comparative analysis of how the various carbon card programs, established or contemplated in Europe and in the USA, are designed and implemented. The findings are these controversies are somewhat groundless.

  2. A study on the isotope effects in the reduction of carbon dioxide by zinc; Etude des effets isotopiques dans la reduction du gaz carbonique par le zinc

    Energy Technology Data Exchange (ETDEWEB)

    Senegacnik, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-06-15

    We have determined the isotope effects which occur in the reduction of carbon dioxide by zinc. It has been shown that in the case of irreversible surface reactions, Bernstein's equation which permits the calculation of the fractionation factor is still valid. These experimental factors are in good agreement with those obtained by calculating the partition functions of the adsorbed activated complexes. In the reaction mechanism used, the model of the activated complex corresponds to the dissociation of one of the carbon oxygen bonds CO{sub 2} {yields} CO + O. Perturbations arising from the slight reversibility of the reaction Zn + CO{sub 2} {r_reversible} ZnO + CO on the isotope effects on the carbon and oxygen atoms have also been calculated. (author) [French] Nous avons etudie les effets isotopiques qui ont lieu dans la reduction du gaz carbonique par le zinc. La validite de l'equation de Bernstein qui permet de calculer le facteur de fractionnement a ete demontree pour le cas d'une reaction irreversible de surface. Ces facteurs de fractionnement experimentaux sont en bon accord avec ceux obtenus par le calcul des fonctions de partition isotopiques des complexes actives adsorbes. Dans le mecanisme de reaction utilise, le modele du complexe active correspond a la dissociation d'une des liaisons carbone oxygene CO{sub 2} {yields} CO + O. Les effets perturbateurs de la reversibilite de la reduction Zn + CO{sub 2} {r_reversible} ZnO + CO sur les effets isotopiques du carbone et ceux de l'oxygene ont ete egalement evalues. (auteur)

  3. Theoretical interpretations and experimental verifications of a radioelectric resonance method for measuring the electronic density and collision frequency in a discharge plasma in gases; Interpretations theoriques et verifications experimentales d'une methode de resonance radioelectrique pour la mesure de la densite d'une decharge dans les gaz

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Trong, Khoi [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Theoretical discussions and experimental verifications of one radioelectric resonance method for measuring plasma electronic density and collision frequency. (author) [French] Discussions theoriques et verifications experimentales sur une methode de resonance radioelectrique pour la mesure de la densite electronique et de la frequence de collision d'un plasma d'une decharge dans le gaz. (auteur)

  4. Approche économique de l'exploration des stockages souterrains de gaz en nappe aquifère Economic Approach to Exploration for Underground Gas Storage Facilities in Aquifers

    Directory of Open Access Journals (Sweden)

    Colonna J.

    2006-11-01

    Full Text Available Dans le cadre de la recherche des stockages souterrains de gaz, le Département Réservoirs Souterrains de Gaz de France est amené à établir un programme d'exploration destiné à sélectionner définitivement, et au moindre coût, les structures capables de satisfaire la demande. Cette sélection passe par une estimation des probabilités de rejet ou d'abandon affectant les différentes structures susceptibles de donner lieu à une exploration. Il faut ensuite constituer le programme d'exploration de chacun des sites retenus après cet examen; ce programme consiste en une liste d'opérations (forage, sismique, essai hydraulique, forage à faible profondeur etc. qui mettront le plus vite possible en évidence : - d'une part les défauts; - d'autre part les principales caractéristiques techniques de la structure étudiée. La règle est d'atteindre la décision sur la faisabilité du site au stockage avec le moindre coût d'exploration. Pour ce faire, une analyse détaillée des causes potentielles d'abandon (recensement des défauts permet de choisir les opérations à effectuer, et d'associer à chacun des défauts recensés, l'opération ou l'ensemble d'opérations permettant de le détecter de façon certaine. Alors les estimateurs économiques tels que l'espérance de dépense, le risque financier, l'espérance de gain, sont calculés pour chacun des programmes, en vue de déterminer l'ordre d'exécution optimal des opérations. L'intérêt d'une telle approche, en ce qui concerne la réduction des dépenses d'exploration, est illustré par un exemple. As part of its work concerning the search for underground gas storage sites, the Underground Storage Department of Gaz de France has established an exploration program for the definitive and lowcost selection of suitable geological structures. This selection involves estimating probabilities of rejecting or abandoning different structures liable to be targets for exploration. The

  5. Improvements in gas supply systems for heavy-water moderated reactors; Etudes de perfectionnements aux systemes d'alimentation en gaz d'un reacteur modere a l'eau lourde

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, G; Hassig, J M; Laurent, N; Thomas, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In a heavy-water moderated reactor cooled by pressurized gas, an important problem from the point of view, of the reactor block and its economics is the choice of the gas supply system. In the pressure tube solution, the whole of the reactor block structure is at a relatively low temperature, whereas the gas supply equipment is at that of the gas, which is much higher. These parts, through which passes the heat carrying fluid have to present as low a resistance as possible to it so as to avoid costly extra blowing power. Finally, they may only be placed in the reactor block after it has been built; the time required for putting them in position should therefore not be too long. The work reported here concerns the various problems arising in the case of each channel being supplied individually by a tube at the entry and the exit which is connected to a main circuit made up of large size collectors. This individual tubing is sufficiently flexible to absorb the differential expansion and the movement of its ends without stresses or prohibitive reactions being produced; the tubing is also of relatively short length so as to reduce the pressure head of the pressurized gas outside the channels; the small amount of space taken up by the tubing makes it possible to assemble it in a manner which is satisfactory from the point of view both of the time required and of the technical quality. (authors) [French] Dans un reacteur modere a l'eau lourde et refroidi au gaz sous pression, un probleme important du point de vue du trace du bloc pile et de son economie est le choix du systeme d'alimentation en gaz. Pour une solution a tubes de force, l'ensemble des structures du bloc reacteur est a temperature relativement faible, alors que les organes d'alimentation en gaz sont a celle, notablement plus elevee, du gaz. Ces organes, traverses par le debit du caloporteur, doivent lui opposer le minimum de resistance afin de ne pas necessiter un supplement onereux de puissance de

  6. Description d'un nouveau brûleur compact. Fonctionnement en régime de gaz prémélangés Description of a New Compact Premixed Gas Burner

    Directory of Open Access Journals (Sweden)

    Minetti R.

    2006-11-01

    Full Text Available On décrit un nouveau brûleur compact à gaz, de haut rendement et d'une puissance variable de 1 à 5 kW. La source de chaleur est une flamme plate d'un prémélange stoechiométrique de gaz naturel et d'air stabilisé sur une grille d'une surface de 100 cm2. Plusieurs grilles en acier inoxydable sont comparées. Elles diffèrent par leur épaisseur, le nombre et la dimension des trous. Un échangeur de chaleur en laiton à circulation d'eau peut être approché jusqu'à 7 mm de la surface du brûleur. La température des gaz frais, le débit et la position de l'échangeur ont été modifiés et les conditions optimales de fonctionnement sont décrites. Les températures à travers les gaz frais, la flamme, les gaz brûlés et les fumées, ont été mesurées. Un modèle simple des échanges de chaleurs est présenté. Il permet une meilleure compréhension des processus de transfert et facilite le choix des conditions opératoires. Dans les meilleures conditions, 93 % du contenu thermique du mélange gazeux est transféré à l'échangeur. Some general characteristics of a compact and efficient gas burner are described (1-5 kW. The heat source is a premixed flat flame stabilized on a 100 cm2 grid fed by a stoechiometric mixture of air and natural gas. Various types of stainless steel grids have been investigated. They differ according to their thickness and to the number and size of the holes. A circulating water heat exchanger made of brass can be approached to the flame as close as 7 mm above the burner surface. The temperature of the inlet gas mixture, the flow rate, and the position of the heat exchanger have been varied. The best working conditions are given as well as the temperature through the fresh gaseous mixture, the temperature profiles of the flame and the temperature of the fumes. From heat transfer calculations a simple model is presented. It gives better insight into the heat transfer processes and facilitates a judicious

  7. The Periodic Pyramid

    Science.gov (United States)

    Hennigan, Jennifer N.; Grubbs, W. Tandy

    2013-01-01

    The chemical elements present in the modern periodic table are arranged in terms of atomic numbers and chemical periodicity. Periodicity arises from quantum mechanical limitations on how many electrons can occupy various shells and subshells of an atom. The shell model of the atom predicts that a maximum of 2, 8, 18, and 32 electrons can occupy…

  8. Book Reviews in Periodicals.

    Science.gov (United States)

    Ettelt, Harold J.

    All recent issues of periodicals found which contain indexed book reviews are listed in this compilation from Drake Memorial Library at the New York State University at Brockport. The periodicals are listed by 29 subject headings in this informal guide designed to be used at Drake Library. The number of reviews in the periodical in a recent year…

  9. National action plan for the promotion of renewable energies 2009-2020. In accordance with Article 4 of European Union Directive 2009/28/EC

    International Nuclear Information System (INIS)

    2012-01-01

    Article 4 of the renewable energy Directive (2009/28/EC) required Member States to submit national renewable energy action plans by 30 June 2010. These plans, were prepared in accordance with the template published by the Commission, and provide detailed road-maps of how each Member State expects to reach its legally binding 2020 target for the share of renewable energy in their final energy consumption. In their national renewable energy action plans Member States set out the sectoral targets, the technology mix they expect to use, the trajectory they will follow and the measures and reforms they will undertake to overcome the barriers to developing renewable energy. Since 2007, France has put in place an ambitious strategy for the development of renewable energies within its territory. A major national consultation, the 'Grenelle Environment Forum', was held from July to November 2007 and led to the emergence of priority targets in terms of controlling energy consumption and promoting renewable energies. It brought together all interested parties (State, local authorities, employers, Trade Unions and associations) and has been unanimously recognised as a solid starting point for later decisions in terms of sustainable development in the territory. Following this consultation, a working group met to establish a reference scenario to achieve the target of 23% of renewable energies in the total final energy consumption. The main determining factors in this scenario are, firstly, major efforts to control energy consumption, particularly in buildings where the scenario provides for a reduction of 38% in consumption by 2020, and, secondly, strong penetration by renewable energies with a targeted additional production of 20 mega-tons of oil equivalent (Mtoe) compared to 2006, or an approximate doubling in production of renewable energies by 2020. Regarding the control of energy consumption, residential and tertiary buildings have been identified as the biggest sources. Around 40% of primary energy is consumed to heat or light these buildings. A large-scale thermal renovation project driven by various financial incentives is in progress. The scheme provides for the insulation of the entire building stock and the installation of several million heating devices and renewable energy production systems. Regarding medium and large scale facilities for renewable energy production, the choice has been made to consider all sources of renewable energy, in order to position France as a major actor in all production technologies. Various incentives and aid schemes have been established: financial aid for research and development projects, aid for the creation of industrial demonstrators, aid for the installation or purchase of equipment, soft loans, etc. France intends to position itself as the leader in technologies as diverse as wind power, maritime energies, solar photovoltaic and thermodynamic, the production of biogas units, etc. From a socio-economic point of view, this means both developing industrial sectors of excellence and creating several hundred thousand jobs, particularly in the fields of building renovation and the installation of renewable energy production equipment. In terms of employment, the achievement of these targets implies accepting three major challenges, as is the case with the other sectors concerned by 'green growth': - support for the emergence of new trades or activities, - support for the changes experienced by trades in certain sectors, - orientation and qualification of labour towards developing sectors. From a geopolitical viewpoint, while this energy policy has the aim of reducing national greenhouse gases, the search for greater security of supply and a reduced dependency on imports of fossil fuels is also a priority target. Through increased use of biofuels, the maintenance of nuclear power stations and the rise in renewable energies, the policy also aims to reduce dependency on fossil energies as much as possible. This reduction of dependency is a long term target, and 2020 only represents an intermediate stage.. Finally, France has chosen a reasoned and organised approach to the development of renewable energies. The development of renewable energies must be linked to other major problems: - air pollution, with in particular strict regulation of those facilities using biomass in terms of particulate emissions; - energy sector life expectancy, particularly those relating to material production or plant chemistry, which already use biomass or which intend to increase its use; - landscape impact, particularly in terms of strict regulation governing the location of wind turbines and a financial incentive in favour of photovoltaic installations integrated into buildings; - land use conflicts, particularly regarding work on different agricultural uses of land and increased vigilance relating to the establishing of photovoltaic facilities and land-based wind-turbines, particularly in agricultural areas; - architectural impact, particularly regarding an adaptation of the thermal requirements for buildings according to their architectural character. While the targets for renewable energy production for 2020 were defined at national level, the establishment of production methods has largely been delegated to local level, with heavy involvement of the territory's local and regional authorities both to promote new technologies and to provide examples. The territory's local and regional authorities and decentralised services, particularly at regional level, are the main principals in terms of the construction of public buildings and are responsible for implementing and monitoring compliance with local town planning regulations

  10. Painful menstrual periods

    Science.gov (United States)

    Menstruation - painful; Dysmenorrhea; Periods - painful; Cramps - menstrual; Menstrual cramps ... into two groups, depending on the cause: Primary dysmenorrhea Secondary dysmenorrhea Primary dysmenorrhea is menstrual pain that ...

  11. Middle Helladic Period

    DEFF Research Database (Denmark)

    Sarri, Kalliopi

    1999-01-01

    and their quality was improved considerably toward the end of this period. The profound cultural innovations of the Middle Helladic period were initially interpreted as a result of violent population movement and troubles provoked by the coming of the first Indo-European races. However, this matter does no more...... Helladic period is considered as a period of economic and social decline it was the time during which the mainland features merged with the insular influence, that is all the Aegean elements which led to the creation of the Mycenaean civilization were mixed in a creative way....

  12. Dépollution des gaz d'échappement des moteurs diesel au moyen de pots catalytiques Depolluting Exhaust Gases from Diesel Engines by Catalytic Mufflers

    Directory of Open Access Journals (Sweden)

    Goldenberg E.

    2006-11-01

    Full Text Available On présente dans cet article les résultats d'une première série de recherches sur la dépollution des gaz d'échappement des moteurs diesel au moyen de pots catalytiques. L'efficacité des catalyseurs à base de platine pour l'oxydation du monoxyde de carbone et des hydrocarbures imbrûlés a pu être établie par des essais sur banc moteur et sur véhicule. L'emploi de certaines phases actives à base de métaux non nobles permet d'autre part d'abaisser la température de début d'oxydation des particules de suie de 380 à 250 °C environ, avec, entre 250 et 350 °C, élimination de 15 à 20 % des produits piégés. L'essai de divers media filtrants a mis en évidence l'importance des phénomènes d'adsorption des revêtements en alumine et a orienté la recherche vers de nouveaux supports pour filtres catalytiques. This article describes the results of a first series of research on the depollution of exhaust gases from diesel engines by catalytic mufflers. The effectiveness of platinum-base catalysts for the oxidation of carbon monoxide and unburned hydrocarbons was determined by test on an engine test bed and on vehicles on the road. The use of some active non-noble metal phases reduced on the other hand the starting oxidation temperature of soot particulates from 380°C to about 250°C, eliminating 15 to 20% of the trapped products between 250 and 350° C. Tests of different filtering media revealed the importance of adsorption phenomena on alumina coatings and directed research toward new supports for catalytic filters.

  13. General design and main problems of a gas-heavy-water power reactor contained in a pressure vessel; Conception generale et principaux problemes d'un reacteur de puissance eau lourde-gaz contenu dans un caisson resistant

    Energy Technology Data Exchange (ETDEWEB)

    Roche, R; Gaudez, J C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In the framework of research carried out on a CO{sub 2}-cooled power reactor moderated by heavy water, the so-called 'pressure vessel' solution involves the total integration of the core, of the primary circuit (exchanges and blowers) and of the fuel handling machine inside a single, strong, sealed vessel made of pre-stressed concrete. A vertical design has been chosen: the handling 'attic' is placed above the core, the exchanges being underneath. This solution makes it possible to standardize the type of reactor which is moderated by heavy-water or graphite and cooled by a downward stream of carbon dioxide gas; it has certain advantages and disadvantages with respect to the pressure tube solution and these are considered in detail in this report. Extrapolation presents in particular.problems due specifically to the heavy water (for example its cooling,its purification, the balancing of the pressures of the heavy water and of the gas, the assembling of the internal structures, the height of the attic, etc. (authors) [French] Dans le cadre des etudes d'un reacteur de puissance modere a l'eau lourde et refroidi-au gaz carbonique, la solution dite 'en caisson' consiste en une integration totale du coeur, du circuit primaire (echangeurs et soufflantes) et du dispositif de manutention du combustible a l'interieur d'un meme caisson etanche et resistant en beton precontraint. La disposition envisagee est verticale; le grenier de manutention est dispose au-dessus du coeur, les echangeurs en dessous. Cette solution, qui permet d'uniformiser les types de reacteurs moderes a l'eau lourde ou au graphite et refroidis par une circulation descendante de gaz carbonique presente, par rapport a la solution a tube de force, des avantages et des inconvenients qui sont analyses dans cette etude. L'extrapolation pose, en particulier, des problemes specifiques a l'eau lourde (tels que son refroidissement, son epuration, l'equilibrage des pression entre l'eau lourde et le gaz, le montage

  14. General design and main problems of a gas-heavy-water power reactor contained in a pressure vessel; Conception generale et principaux problemes d'un reacteur de puissance eau lourde-gaz contenu dans un caisson resistant

    Energy Technology Data Exchange (ETDEWEB)

    Roche, R.; Gaudez, J.C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    In the framework of research carried out on a CO{sub 2}-cooled power reactor moderated by heavy water, the so-called 'pressure vessel' solution involves the total integration of the core, of the primary circuit (exchanges and blowers) and of the fuel handling machine inside a single, strong, sealed vessel made of pre-stressed concrete. A vertical design has been chosen: the handling 'attic' is placed above the core, the exchanges being underneath. This solution makes it possible to standardize the type of reactor which is moderated by heavy-water or graphite and cooled by a downward stream of carbon dioxide gas; it has certain advantages and disadvantages with respect to the pressure tube solution and these are considered in detail in this report. Extrapolation presents in particular.problems due specifically to the heavy water (for example its cooling,its purification, the balancing of the pressures of the heavy water and of the gas, the assembling of the internal structures, the height of the attic, etc. (authors) [French] Dans le cadre des etudes d'un reacteur de puissance modere a l'eau lourde et refroidi-au gaz carbonique, la solution dite 'en caisson' consiste en une integration totale du coeur, du circuit primaire (echangeurs et soufflantes) et du dispositif de manutention du combustible a l'interieur d'un meme caisson etanche et resistant en beton precontraint. La disposition envisagee est verticale; le grenier de manutention est dispose au-dessus du coeur, les echangeurs en dessous. Cette solution, qui permet d'uniformiser les types de reacteurs moderes a l'eau lourde ou au graphite et refroidis par une circulation descendante de gaz carbonique presente, par rapport a la solution a tube de force, des avantages et des inconvenients qui sont analyses dans cette etude. L'extrapolation pose, en particulier, des problemes specifiques a l'eau lourde (tels que son refroidissement, son epuration

  15. On some periodicity effects

    DEFF Research Database (Denmark)

    Sorokin, Sergey V.

    2015-01-01

    The talk is concerned with the modelling of wave propagation in and vibration of periodic elastic structures. Although analysis of wave-guide properties of infinite periodic structures is a well establish research subject, some issues have not yet been fully addressed in the literature. The aim o...

  16. The Living Periodic Table

    Science.gov (United States)

    Nahlik, Mary Schrodt

    2005-01-01

    To help make the abstract world of chemistry more concrete eighth-grade students, the author has them create a living periodic table that can be displayed in the classroom or hallway. This display includes information about the elements arranged in the traditional periodic table format, but also includes visual real-world representations of the…

  17. Periods and Nori motives

    CERN Document Server

    Huber, Annette

    2017-01-01

    This book casts the theory of periods of algebraic varieties in the natural setting of Madhav Nori’s abelian category of mixed motives. It develops Nori’s approach to mixed motives from scratch, thereby filling an important gap in the literature, and then explains the connection of mixed motives to periods, including a detailed account of the theory of period numbers in the sense of Kontsevich-Zagier and their structural properties. Period numbers are central to number theory and algebraic geometry, and also play an important role in other fields such as mathematical physics. There are long-standing conjectures about their transcendence properties, best understood in the language of cohomology of algebraic varieties or, more generally, motives. Readers of this book will discover that Nori’s unconditional construction of an abelian category of motives (over fields embeddable into the complex numbers) is particularly well suited for this purpose. Notably, Kontsevich's formal period algebra represents a to...

  18. Mean-periodic functions

    Directory of Open Access Journals (Sweden)

    Carlos A. Berenstein

    1980-01-01

    Full Text Available We show that any mean-periodic function f can be represented in terms of exponential-polynomial solutions of the same convolution equation f satisfies, i.e., u∗f=0(μ∈E′(ℝn. This extends to n-variables the work of L. Schwartz on mean-periodicity and also extends L. Ehrenpreis' work on partial differential equations with constant coefficients to arbitrary convolutors. We also answer a number of open questions about mean-periodic functions of one variable. The basic ingredient is our work on interpolation by entire functions in one and several complex variables.

  19. Modélisation et analyse exergetique d'un système de gazéification des résidus de bois en vue de la production d'électricité

    OpenAIRE

    Razanajatovo , Tahiry Landry; Morau , Dominique; Rakotondramiarana , Hery Tiana

    2016-01-01

    International audience; Cette étude s'est focalisée sur l'opportunité de l'utilisation des ressources renouvelables, comme le bois, dans le domaine énergétique. La modélisation de chaque étape de transformation de l'énergie des résidus bois en électricité est présentée : transformation du bois en gaz de synthèse par le biais d'un gazogène – conversion de l'énergie calorifique du syngaz en énergie mécanique par l'utilisation d'un moteur à combustion interne – conversion de l'énergie mécanique ...

  20. Model-Based Throttle Control using Static Compensators and Pole Placement Commande des gaz basée sur un modèle utilisant des compensateurs statiques et un placement de pôles

    Directory of Open Access Journals (Sweden)

    Thomasson A.

    2011-10-01

    Full Text Available In modern spark ignited engines, the throttle is controlled by the Electronic Control Unit (ECU, which gives the ECU direct control of the air flow and thereby the engine torque. This puts high demands on the speed and accuracy of the controller that positions the throttle plate. The throttle control problem is complicated by two strong nonlinear effects, friction and limp-home torque. This paper proposes the use of two, simultaneously active, static compensators to counter these effects and approximately linearize the system. A PID controller is designed for the linearized system, where pole placement is applied to design the PD controller and a gain scheduled I-part is added for robustness against model errors. A systematic procedure for generating compensator and controller parameters from open loop experiments is also developed. The controller performance is evaluated both in simulation, on a throttle control benchmark problem, and experimentally. A robustness investigation pointed out that the limp-home position is an important parameter for the controller performance, this is emphasized by the deviations found in experiments. The proposed method for parameter identification achieves the desired accuracy. Au sein des moteurs à allumage commandé modernes, les gaz sont régulés par le boîtier de commande électronique (ECU; Electronic Control Unit, qui permet la régulation directe par l’ECU du flux d’air et ainsi du couple moteur. Cela conduit à des exigences élevées quant à la vitesse et à la précision du régulateur qui positionne le papillon des gaz. Le problème de commande des gaz est compliqué par deux forts effets non linéaires, le frottement et le couple de mode de secours (“limp-home”. Cet article propose l’utilisation de deux compensateurs statiques, actifs simultanément, pour contrer ces effets et linéariser approximativement le système. Un régulateur PID est conçu pour le système linéarisé, où un

  1. Mobility of Rb{sup +} and Cs{sup +} ions in gases at high pressures; Mobilite des ions Rb{sup +} et Cs{sup +} dans les gaz a haute pression

    Energy Technology Data Exchange (ETDEWEB)

    Bacconnet, E. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    A theoretical study and mobility measurements have been made of Rb{sup +} and Cs{sup +} ions moving in gases at high pressures (10{sup -2} to 25 kg/cm{sup 2}). The theoretical study has been effected using the results of P. Langevin who considers the ions and molecules as elastic spheres and takes into account the electrical polarization forces. The practical work has been carried out using the Rb{sup +} and Cs{sup +} ions emitted by a thermal source; for the measurement of their velocity the method using an ionic beam cut by four grids was employed. Since the source does not work in atmospheres containing oxygen (even in the combined state) the tests only involved pure gases: nitrogen, argon, helium at pressures of from 10{sup -2} to 12 kg/cm{sup 2}. The overall results show that the Rb{sup +} and Cs{sup +} ionic mobilities are very similar and that for fairly-short times spent by the ions in the gas, the measurement results are in agreement with theory. An increase in these times favours a degradation of the ions, which always leads to a decrease in the mobility. This effect is most marked in helium. The gases argon and nitrogen behave identically towards Rb{sup +} and Cs{sup +} ions. (author) [French] Une etude theorique et des mesures de mobilite ont ete effectuees pour des ions Rb{sup +} et Cs{sup +} se deplacant dans des gaz a haute pression (10{sup -2} a 25 kg/cm{sup 2}). L'etude theorique a ete effectuee en utilisant les resultats de P. Langevin qui assimile les ions et les molecules a des spheres elastiques et tient compte des forces de polarisation electrique. L'etude pratique a ete realisee en utilisant des ions Rb{sup +} et Cs{sup +} emis par une source thermique et pour la mesure de leur vitesse, la methode de coupure du faisceau ionique au moyen de quatre grilles a ete adoptee. La source ne fonctionnant pas dans des atmospheres contenant de l'oxygene (meme a l'etat combine) les essais ont seulement porte sur des gaz purs: azote

  2. Mobility of Rb{sup +} and Cs{sup +} ions in gases at high pressures; Mobilite des ions Rb{sup +} et Cs{sup +} dans les gaz a haute pression

    Energy Technology Data Exchange (ETDEWEB)

    Bacconnet, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    A theoretical study and mobility measurements have been made of Rb{sup +} and Cs{sup +} ions moving in gases at high pressures (10{sup -2} to 25 kg/cm{sup 2}). The theoretical study has been effected using the results of P. Langevin who considers the ions and molecules as elastic spheres and takes into account the electrical polarization forces. The practical work has been carried out using the Rb{sup +} and Cs{sup +} ions emitted by a thermal source; for the measurement of their velocity the method using an ionic beam cut by four grids was employed. Since the source does not work in atmospheres containing oxygen (even in the combined state) the tests only involved pure gases: nitrogen, argon, helium at pressures of from 10{sup -2} to 12 kg/cm{sup 2}. The overall results show that the Rb{sup +} and Cs{sup +} ionic mobilities are very similar and that for fairly-short times spent by the ions in the gas, the measurement results are in agreement with theory. An increase in these times favours a degradation of the ions, which always leads to a decrease in the mobility. This effect is most marked in helium. The gases argon and nitrogen behave identically towards Rb{sup +} and Cs{sup +} ions. (author) [French] Une etude theorique et des mesures de mobilite ont ete effectuees pour des ions Rb{sup +} et Cs{sup +} se deplacant dans des gaz a haute pression (10{sup -2} a 25 kg/cm{sup 2}). L'etude theorique a ete effectuee en utilisant les resultats de P. Langevin qui assimile les ions et les molecules a des spheres elastiques et tient compte des forces de polarisation electrique. L'etude pratique a ete realisee en utilisant des ions Rb{sup +} et Cs{sup +} emis par une source thermique et pour la mesure de leur vitesse, la methode de coupure du faisceau ionique au moyen de quatre grilles a ete adoptee. La source ne fonctionnant pas dans des atmospheres contenant de l'oxygene (meme a l'etat combine) les essais ont seulement porte sur des gaz purs: azote, argon, helium et pour

  3. Project of law relative to the electricity and gas public utilities and to the power and gas companies; Projet de loi relatif au service public de l'electricite et du gaz et aux entreprises electriques et gazieres

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This document is the definitive text of this project of law adopted by the French house of commons. The aim of this law is to allow the administrations to avoid to use their eligibility right with the opening of the electricity and gas markets to competition. It changes the juridical status of the two public utilities Electricite de France (EdF) and Gaz de France (GdF) into two anonymous companies and creates two additional companies for the management of the power and gas networks. It ensures also the transposition of the European directives from June 26, 2003 (2003/54/CE and 2003/55/CE). It contains some proper dispositions and modifies various existing French laws, in particular the law no. 46-628 from April 8, 1946 about the electricity and gas nationalization and the law no. 2000-108 from February 10, 2000 relative to the modernization and development of the electric public utility. (J.S.)

  4. Painful periods (dysmenorrhea) (image)

    Science.gov (United States)

    Primary dysmenorrhea is a normal cramping of the lower abdomen caused by hormone-induced uterine contractions before the period. Secondary dysmenorrhea may be caused by abnormal conditions such as ...

  5. Vaginal bleeding between periods

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003156.htm Vaginal bleeding between periods To use the sharing features ... this page, please enable JavaScript. This article discusses vaginal bleeding that occurs between a woman's monthly menstrual ...

  6. Super periodic potential

    Science.gov (United States)

    Hasan, Mohammd; Mandal, Bhabani Prasad

    2018-04-01

    In this paper we introduce the concept of super periodic potential (SPP) of arbitrary order n, n ∈I+, in one dimension. General theory of wave propagation through SPP of order n is presented and the reflection and transmission coefficients are derived in their closed analytical form by transfer matrix formulation. We present scattering features of super periodic rectangular potential and super periodic delta potential as special cases of SPP. It is found that the symmetric self-similarity is the special case of super periodicity. Thus by identifying a symmetric fractal potential as special cases of SPP, one can obtain the tunnelling amplitude for a particle from such fractal potential. By using the formalism of SPP we obtain the close form expression of tunnelling amplitude of a particle for general Cantor and Smith-Volterra-Cantor potentials.

  7. Establishing contract periods

    International Nuclear Information System (INIS)

    Huffman, F.C.

    1978-01-01

    The lead time for executing the Adjustable Fixed-Commitment (AFC) contract and exceptions which may be considered are discussed. The initial delivery period is also discussed. Delays, deferrals, and schedule adjustment charges are finally considered

  8. The Periodic Table CD.

    Science.gov (United States)

    Banks, Alton J.; Holmes, Jon L.

    1995-01-01

    Describes the characteristics of the digitized version of The Periodic Table Videodisc. Provides details about the organization of information and access to the data via Macintosh and Windows computers. (DDR)

  9. Setting the Periodic Table.

    Science.gov (United States)

    Saturnelli, Annette

    1985-01-01

    Examines problems resulting from different forms of the periodic table, indicating that New York State schools use a form reflecting the International Union of Pure and Applied Chemistry's 1984 recommendations. Other formats used and reasons for standardization are discussed. (DH)

  10. Supersymmetrically transformed periodic potentials

    OpenAIRE

    C, David J. Fernandez

    2003-01-01

    The higher order supersymmetric partners of a stationary periodic potential are studied. The transformation functions associated to the band edges do not change the spectral structure. However, when the transformation is implemented for factorization energies inside of the forbidden bands, the final potential will have again the initial band structure but it can have bound states encrusted into the gaps, giving place to localized periodicity defects.

  11. Thyrotoxic periodic paralysis

    OpenAIRE

    Rojith Karandode Balakrishnan; Suresh Rama Chandran; Geetha Thirumalnesan; Nedumaran Doraisamy

    2011-01-01

    This article aims at highlighting the importance of suspecting thyrotoxicosis in cases of recurrent periodic flaccid paralysis; especially in Asian men to facilitate early diagnosis of the former condition. A case report of a 28 year old male patient with recurrent periodic flaccid paralysis has been presented. Hypokalemia secondary to thyrotoxicosis was diagnosed as the cause of the paralysis. The patient was given oral potassium intervention over 24 hours. The patient showed complete recove...

  12.  Standardy rachunkowości stanowiące podstawę sporządzania sprawozdań finansowych przez jednostki wydobywające gaz łupkowy w Polsce i w Stanach Zjednoczonych

    Directory of Open Access Journals (Sweden)

    Anna Galimska

    2015-12-01

    Full Text Available Celem artykułu jest analiza oraz porównanie standardów rachunkowości wykorzystywanych przez przedsiębiorstwa poszukujące i wydobywające gaz łupkowy w Stanach Zjednoczonych i w Polsce. Autorka dokonała zestawienia regulacji służących do sporządzania i prezentacji sprawozdań finansowych, na których opierają się jednostki eksploatujące węglowodory niekonwencjonalne. Wciąż postępujący rozwój rynków kapitałowych znajduje swoje odzwierciedlenie w intensyfikacji oczekiwań interesariuszy względem atrybutów, którymi winny charakteryzować się sprawozdania finansowe. Rozważania zawarte w artykule ukazują wysoki poziom specjalizacji amerykańskich standardów rachunkowości, na których bazują podmioty wydobywające gaz łupkowy w Stanach Zjednoczonych. Natomiast standardy międzynarodowe poruszają jedynie kwestię początkowego stadium procesu wydobycia alternatywnych węglowodorów, co rzutuje na spójność przygotowywanych na ich podstawie sprawozdań finansowych. Ponadto istotna jest kwestia rozbieżności merytorycznych czy też interpretacyjnych analizowanych standardów zarówno w zakresie identyfikacji kosztów oraz ich klasyfikacji, jak i określania wysokości odpisów z tytułu utraty wartości.

  13. Contribution to the study of the desorption of fission gases formed in irradiated uranium oxide; Contribution a l'etude de la desorption des gaz de fission formes dans l'oxyde d'uranium irradie

    Energy Technology Data Exchange (ETDEWEB)

    Berry, J -L; Darras, R; Roger, B [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1966-09-01

    The release of {sup 133}Xe from irradiated UO{sub 2} has been studied in the temperature range 1300 to 1900 deg C, using various monocrystalline or sintered samples. Up to 1600 deg C, this release is proportional to the square root of the time and thus occurs essentially by diffusion. The apparent diffusion constant D' decreases and the activation energy of the corresponding process increases as the integrated neutron flux received by the fuel increases. As the density of the sintered samples decreases however, the activation energy of the release also decreases, so that the difference between D' values for sintered samples of different densities decreases as the temperature rises. Finally, above 1600 deg C, the fission gas release phenomenon is governed by UO{sub 2} evaporation, and all the different types of oxide studied have similar behaviors, characterized by poor retention of these gases. (authors) [French] La desorption du xenon 133 forme dans le bioxyde d'uranium irradie a ete etudiee dans l'intervalle de 1300 a 1900 C, a l'aide de differents echantillons monocristallins ou frittes. Jusqu'a 1600 C, elle s'effectue proportionnellement a la racine carree du temps, donc essentiellement par diffusion. La pseudo-constante de desorption D' decroit et l'energie d'activation du processus correspondant croit lorsque le flux de neutrons integre recu par le combustible augmente. Cependant, lorsque la densite des frittes diminue, l'energie d'activation de desorption diminue egalement, de sorte que l'ecart entre les valeurs de D' relatives a des frittes de densites differentes se restreint lorsque, la temperature s'eleve. Finalement, au-dessus de 1600 C, l'evaporation de l'UO{sub 2} regit le phenomene de liberation des gaz de fission, et toutes les qualites d'oxyde etudiees presentent alors des comportements voisins a cet egard, caracterises par une mediocre retention de ces gaz. (auteurs)

  14. Visual Investigation of Retrograde Phenomena and Gas Condensate Flow in Porous Media Étude visuelle des phénomènes rétrogrades et de l'écoulement des gaz de condensat en milieux poreux

    Directory of Open Access Journals (Sweden)

    Danesh A.

    2006-11-01

    Full Text Available The mechanism of retrograde condensation and the flow of gas-condensate in horizontal porous media under simulated reservoir conditions were visually studied. Two-dimensional glass micromodels with homogeneous pore structures, as well as heterogeneous patterns, reproduced from real rock micrographs were employed in this study. Depletion tests were carried out using synthetic multicomponent hydrocarbon gas mixtures and also a North Sea gas condensate. The multiphase flow behaviour of the tested systems, as observed and recorded on video, is presented here along with the measured data. In water-wet pores, condensate was observed to be formed as a continuous thin film on connate water, which was the preferred site for condensation. Pressure reduction below the system cricondenbar resulted in the growth of the condensate almost exclusively on water rings at pore throats and dead end pores. The condensate was observed to flow through thin films even at low saturations, with little contribution to the condensate recovery. The rate of pressure depletion influenced the gas flow shear and was found to strongly affect the condensate propagation. Local instabilities could promote significant condensate movement in pore sections which would only be retarded further downstream by capillary effects diminishing the condensate recovery. Relative permeability-saturation relation-ships for gas-condensate flow should not be expected to take the same form as the oil-gas relative permeability for solution gas or external gas drive. Le mécanisme de la condensation rétrograde et l'écoulement des gaz de condensat en milieu poreux horizontal dans une simulation des conditions naturelles ont fait l'objet d'études visuelles. Des micromodèles en verre bi-dimensionnels à structure poreuse homogène, et des éléments hétérogènes reproduisant des micrographies de roches réelles, ont été utilisés pour cette étude. Des essais d'épuisement ont été effectu

  15. Karabük İlindeki Hava Kirliliğinin Doğal Gaz Kullanımı İle Değişimi

    Directory of Open Access Journals (Sweden)

    Abdülaziz YILDIZ

    2012-12-01

    Full Text Available ÖzetFosil kaynaklı yakıtların kullanımı, hava kirliliğine sebebiyet veren en önemli unsurlardan bir tanesidir. Bu yakıtların bilinçsizce kullanılması sonucunda çevre problemlerine özellikle de hava kirliliğine neden olmaktadır. Yapılan bu çalışmada, Karabük ilinin doğalgaz kullanmaya başlamadan önceki ve doğalgaza geçiş ile hava kirlilik parametreleri (SO2 ve PM10 incelenmiştir. Doğal gaz kullanımının hava kalitesine etkisi araştırılmıştır. İlde ısınma ihtiyacını karşılamak için kömür, fuel-oil ve mazot kullanılırken 2010 yılı itibariyle doğal gaza geçilmiştir. Doğal gazın kullanılmaya başlanmasıyla bu yakıtların kullanımı azalmıştır. Çalışmanın sonunda, Hava Kalitesi Değerlendirme ve Yönetimi Yönetmeliğinde (HKDYY belirtilen, SO2 için 250 μg/m3 değerinin doğal gaz kullanımına geçilmeden önce bazı aylarda üzerinde olduğu görülmüş ve doğal gaz kullanılmaya başlanmasından sonraki dönemlerde ise 250 μg/m3 değerinin aşılmadığı görülmüştür. PM10 için yönetmelikte belirtilen 200 μg/m3 değerinin kış sezonunda aşıldığı tespit edilmiştir. 2010 yılında Doğal gaz kullanımına geçiş ile birlikte bu değerde tekrar bir düşüş gözlenmiştir. Doğal gaz kullanım oranı artıkça havadaki SO2 ve PM10 değerlerinde ciddi düşüşler olduğu gözlenmiştir.AbstractThe Usage of fossil origin fuels is one of the most important cause of air pollution. The usage of these fuels unconsciously causes environmental problems especially air pollution. In this study air pollution parameters (SO2 ve PM10 were analyzed before and after the usage of natural gas in Karabuk. The effect of usage natural gas on air quality is researched. In this city before 2010 coal, foul-oil and diesel were used to provide heat demanded then it is started using natural gas by 2010.With starting the usage of natural gas, the usage of these kind of fuels (coal, foul

  16. Energy Equation Derivation of the Oil-Gas Flow in Pipelines Dérivation de l’équation d’énergie de l’écoulement huile-gaz dans des pipelines

    Directory of Open Access Journals (Sweden)

    Duan J.M

    2012-09-01

    well describe the oil-gas two-phase flow. Lors de la simulation d’un écoulement multiphasique huile-gaz dans une conduite, le calcul thermodynamique représente un processus important en interaction avec le calcul hydraulique; il influence la convergence du programme et la précision des résultats. La forme de l’équation d’énergie constitue la clef du calcul thermodynamique. Basée sur l’équation d’énergie de l’écoulement huile-gaz dans un pipeline, la formule de chute de température explicite (ETDF; Explicit Temperature Drop Formula est dérivée pour un calcul de température d’état stable huile-gaz. Cette nouvelle équation d’énergie prend en compte de nombreux facteurs, tels que l’effet Joule-Thomson, le travail de pression, le travail de frottement, ainsi que l’incidence des ondulations de terrain et le transfert de chaleur avec le milieu extérieur le long de la ligne. Ainsi, il s’agit d’une forme globale de l’équation d’énergie, laquelle pourrait décrire précisément la réalité d’un pipeline à phases multiples. Pour cette raison, un certain nombre de points de vue de la littérature à propos du calcul de température d’un écoulement diphasique huile-gaz dans des pipelines sont passés en revue. L’élimination de la boucle d’itération de température et l’intégration de l’équation de température explicite, au lieu de l’équation d’énergie d’enthalpie, dans le calcul conjugué hydraulique et thermique, se sont avérées améliorer l’efficacité de l’algorithme. Le calcul a été appliqué non seulement au modèle de composants mais aussi au modèle Black-Oil. Ce modèle est incorporé respectivement dans le modèle de composants ainsi que le modèle Black-Oil et deux simulations sont effectuées sur deux pipelines en service, les pipelines multiphasiques Yingmai-Yaha et Lufeng; les résultats de température sont comparés à la simulation calculée par OLGA et aux résultats mesurés. Il

  17. Periodic table of elements

    International Nuclear Information System (INIS)

    Fluck, E.; Heumann, K.G.

    1985-01-01

    Following a recommendation by the International Union for Pure and Applied Chemistry (IUPAC), the groups of the periodic table shall be numbered from 1 to 18, instead of I to VIII as before. The recommendations has been approved of by the Committee on Nomenclature of the American Chemical Society. The new system abandons the distinction between main groups (a) and auxiliary groups (b), which in the past frequently has been the reason for misunderstandings between European and American chemists, due to different handling. The publishing house VCH Verlagsgesellschaft recently produced a new periodic table that shows the old and the new numbering system together at a glance, so that chemists will have time to get familiar with the new system. In addition the new periodic table represents an extensive data compilation arranged by elements. The front page lists the chemical properties of elements, the back page their physical properties. (orig./EF) [de

  18. Thyrotoxic periodic paralysis

    Directory of Open Access Journals (Sweden)

    Rojith Karandode Balakrishnan

    2011-01-01

    Full Text Available This article aims at highlighting the importance of suspecting thyrotoxicosis in cases of recurrent periodic flaccid paralysis; especially in Asian men to facilitate early diagnosis of the former condition. A case report of a 28 year old male patient with recurrent periodic flaccid paralysis has been presented. Hypokalemia secondary to thyrotoxicosis was diagnosed as the cause of the paralysis. The patient was given oral potassium intervention over 24 hours. The patient showed complete recovery after the medical intervention and was discharged after 24 hours with no residual paralysis. Thyrotoxic periodic paralysis (TPP is a complication of thyrotoxicosis, more common amongst males in Asia. It presents as acute flaccid paralysis in a case of hyperthyroidism with associated hypokalemia. The features of thyrotoxicosis may be subtle or absent. Thus, in cases of recurrent or acute flaccid muscle paralysis, it is important to consider thyrotoxicosis as one of the possible causes, and take measures accordingly.

  19. Impact environnemental d'une désulfuration poussée des gazoles Environmental Impact of Gaz Oil Desulfurization

    Directory of Open Access Journals (Sweden)

    Armengol C.

    2006-11-01

    Full Text Available En une dizaine d'années, le diesel a connu un développement spectaculaire sur les marchés automobile français et européen et pourrait atteindre, en 1995, la moitié des immatriculations de véhicules particuliers en France et le quart en Europe de l'Ouest. Cette situation n'est évidemment pas sans poser de problèmes. Problèmes environnementaux puisque le moteur diesel est une source plus importante d'émissions d'oxydes d'azote et de particules que le convertisseur essence, mais également au niveau de l'industrie du raffinage qui, en France, n'est plus en mesure de satisfaire la demande en gazole. De plus, à compter du 1er octobre 1996, la teneur en soufre du gazole routier ne devra pas excéder 0,05 %, conformément aux nouvelles spécifications européennes. Cette perspective de production de carburants fortement désulfurés va affecter directement l'équilibre en hydrogène de la raffinerie et donc les autoconsommations et les émissions de CO2. L'objectif de cette étude est de mesurer l'impact sur l'environnement d'une réduction de la teneur en soufre des gazoles de 0,3 à 0,05 %. Le bilan est réalisé sur l'ensemble de la filière énergétique, depuis l'extraction du pétrole jusqu'à la combustion du carburant dans le moteur. Les gains et les pertes en termes de pollution locale ou globale sont évalués suivant la nature de l'hydrogène utilisé (oxydation partielle de résidus sous vide ou de charbon, reformage à la vapeur de gaz naturel ou de naphta électrolyse et la nature de la charge à traiter (gazole straight run ou light cycle oil lors de l'hydrodésulfuration. Over the past decade, diesel had made large advances in the French and European automobile markets. In 1995, diesel could account for half of all private vehicle registrations in France, and a quarter in Western Europe. This situation inevitably raises a number of problems : environmental problems, because the diesel engine emits more nitrogen oxides and

  20. Fluctuations Magnetiques des Gaz D'electrons Bidimensionnels: Application AU Compose Supraconducteur LANTHANE(2-X) Strontium(x) Cuivre OXYGENE(4)

    Science.gov (United States)

    Benard, Pierre

    Nous presentons une etude des fluctuations magnetiques de la phase normale de l'oxyde de cuivre supraconducteur La_{2-x}Sr _{x}CuO_4 . Le compose est modelise par le Hamiltonien de Hubbard bidimensionnel avec un terme de saut vers les deuxiemes voisins (modele tt'U). Le modele est etudie en utilisant l'approximation de la GRPA (Generalized Random Phase Approximation) et en incluant les effets de la renormalisation de l'interaction de Hubbard par les diagrammes de Brueckner-Kanamori. Dans l'approche presentee dans ce travail, les maximums du facteur de structure magnetique observes par les experiences de diffusion de neutrons sont associes aux anomalies 2k _{F} de reseau du facteur de structure des gaz d'electrons bidimensionnels sans interaction. Ces anomalies proviennent de la diffusion entre particules situees a des points de la surface de Fermi ou les vitesses de Fermi sont tangentes, et conduisent a des divergences dont la nature depend de la geometrie de la surface de Fermi au voisinage de ces points. Ces resultats sont ensuite appliques au modele tt'U, dont le modele de Hubbard usuel tU est un cas particulier. Dans la majorite des cas, les interactions ne determinent pas la position des maximums du facteur de structure. Le role de l'interaction est d'augmenter l'intensite des structures du facteur de structure magnetique associees a l'instabilite magnetique du systeme. Ces structures sont souvent deja presentes dans la partie imaginaire de la susceptibilite sans interaction. Le rapport d'intensite entre les maximums absolus et les autres structures du facteur de structure magnetique permet de determiner le rapport U_ {rn}/U_{c} qui mesure la proximite d'une instabilite magnetique. Le diagramme de phase est ensuite etudie afin de delimiter la plage de validite de l'approximation. Apres avoir discute des modes collectifs et de l'effet d'une partie imaginaire non-nulle de la self-energie, l'origine de l'echelle d'energie des fluctuations magnetiques est examinee

  1. Heat transfer by gas-liquid mixture in forced turbulent flow with weak vaporization of the liquid phase (1962); Transfert de chaleur par melange de liquide et de gaz en convection forcee turbulente avec faible vaporisation de la phase liquide (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Huyghe, J; Mondin, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1962-07-01

    The present study deals with measures of heat transfer and pressure drop in two-phase liquid flow. The stream is of annular dispersed type, obtained by introducing a small quantity of liquid in a gas turbulent flow. The heat transfer experiments are performed without vaporization of the liquid phase. A notable improvement of the heat transfer coefficient of such a stream is observed, compared with a gas-alone or liquid-alone flow. The improvement concerning the gas-alone is of about 20 when it is compared with the same gas Reynolds's number, of about 8 when it is compared with the same total mass flow rate. A hydrodynamic study of the flow pattern lets us know the original structure of the flow, and allows to foresee the experimental results by means of a simplified theory. (authors) [French] II est fait etat de mesures de transfert thermique et de perte de charge dans un ecoulement en double phase gaz-liquide. L'ecoulement est du type annulaire disperse, obtenu par injection d'une faible quantite de liquide dans un ecoulement gazeux en regime turbulent. Les experiences de transfert thermique sont menees sans vaporisation de la phase liquide. On note une amelioration sensible du coefficient de transfert thermique dans un tel ecoulement par rapport a un ecoulement de gaz seul ou de liquide seul. L'augmentation est de l'ordre de 20 par rapport au gaz seul si on opere a meme nombre de REYNOLDS du gaz, de l'ordre de 8 si on opere a meme debit massique total. Une etude hydrodynamique rapide de l'ecoulement permet de connaitre la structure originale de l'ecoulement, puis de prevoir par une theorie simplifiee le phenomene thermique observe. (auteurs)

  2. Analysis of Simultaneous Gas-Liquid Flow Through an Orifice and Its Application to Flow Metering Etude de l'écoulement simultané d'un mélange gaz-liquide à travers un orifice et son application à la mesure du débit

    Directory of Open Access Journals (Sweden)

    Pascal H.

    2006-11-01

    Full Text Available The purpose of this article is to show a more accurate orifice equation for a two-phase flow, such a compressible mixture of gas and liquid. The orifice equation given here con be used for the measurement of a gas-liquid mixture of fine emulsions by the orificemeter method. From the thermodynamic point of view, an equation of state has been formulated which provides the relationship between the specific mass of the mixture and pressure, under conditions of adiabatic expansion. The results obtained enable the mass flow rates of gas and liquid ta be determined without separation of the phases, provided thot the gas liquid mass ratio is known. The critical pressure ratio corresponding ta sonic velocity is also determined. Cet article présente une relation plus précise pour l'écoulement d'un système à deux phases, tel qu'un mélange compressible gaz-liquide, à travers un diaphragme. Cette relation peut être utilisée pour des mesures de mélanges gaz-liquide très finement divisés, c'est-à-dire des émulsions ou brouillards, par la méthode du diaphragme en paroi mince. Du point de vue thermodynamique, on a formulé une équation d'état donnant la relation entre la masse spécifique du mélange et la pression dans des conditions d'expansion adiabatique. Les résultats obtenus per-mettent de déterminer le débit massique du gaz et du liquide, sans séparation des deux phases, à condition que le rapport de masse gaz-liquide soit connu. On détermine également le rapport de pression critique correspondantà la vitesse du son.

  3. Reconsideration of Methane Isotope Signature As a Criterion for the Genesis of Natural Gas: Influence of Migration on Isotopic Signatures Reconsidération de la signature isotopique du méthane comme critère pour la genèse du gaz naturel : influence de la migration sur les signatures isotopiques

    Directory of Open Access Journals (Sweden)

    Pernaton E.

    2006-11-01

    Full Text Available Experiments were performed in the purpose of studying the isotopic consequences of the diffusional transport of hydrocarbon gases through sediment rocks. Linked to a numerical model, these gas diffusion experiments through a shale porous plug allowed us to correlate porosity and diffusivity of the migration medium. Significant isotopic fractionations (carbon and hydrogen of methane, and ethane at a lesser degree were observed. This is in contradiction with the actual dogma of isotope geochemistry of natural gases which claims that no fractionation occurs during gas migration. The genetic characterization of natural gases by using the isotopic signature of methane appears as an ambiguous method. Plusieurs expériences ont été réalisées dans le but d'étudier les conséquences isotopiques du transport par diffusion des gaz hydrocarbures au travers des roches sédimentaires. Associées à un modèle numérique, ces expériences de diffusion au travers d'une membrane d'argile reconstituée nous ont permis de corréler deux paramètres pétrophysiques du milieu de migration : la porosité et la diffusivité. D'importants fractionnements isotopiques ont été observés au cours de la diffusion du méthane et, à plus petite échelle, lors de la diffusion de l'éthane. Ces résultats remettent en cause le dogme actuel de la géochimie isotopique des gaz naturels qui stipule que la migration des gaz ne peut induire de fractionnements isotopiques. En conséquence, les méthodes de caractérisation génétique des gaz naturels utilisant la signature isotopique du méthane apparaissent comme insuffisantes.

  4. Glaz da glaz ili gaz da gaz? / Jevgenija Garanzha

    Index Scriptorium Estoniae

    Garanža, Jevgenija, 1979-

    2005-01-01

    Euroopa Liidu ja Venemaa tippkohtumisest Londonis, kõnealusteks teemadeks lihtsustatud viisarežiim, piirilepingud Eesti ja Lätiga, vähemusrahvuste olukord nendes riikides, põhiteemaks kujuneb Euroopa sõltuvus Venemaa gaasist ja naftast

  5. Periodically poled silicon

    Science.gov (United States)

    Hon, Nick K.; Tsia, Kevin K.; Solli, Daniel R.; Khurgin, Jacob B.; Jalali, Bahram

    2010-02-01

    Bulk centrosymmetric silicon lacks second-order optical nonlinearity χ(2) - a foundational component of nonlinear optics. Here, we propose a new class of photonic device which enables χ(2) as well as quasi-phase matching based on periodic stress fields in silicon - periodically-poled silicon (PePSi). This concept adds the periodic poling capability to silicon photonics, and allows the excellent crystal quality and advanced manufacturing capabilities of silicon to be harnessed for devices based on χ(2)) effects. The concept can also be simply achieved by having periodic arrangement of stressed thin films along a silicon waveguide. As an example of the utility, we present simulations showing that mid-wave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50% based on χ(2) values measurements for strained silicon reported in the literature [Jacobson et al. Nature 441, 199 (2006)]. The use of PePSi for frequency conversion can also be extended to terahertz generation. With integrated piezoelectric material, dynamically control of χ(2)nonlinearity in PePSi waveguide may also be achieved. The successful realization of PePSi based devices depends on the strength of the stress induced χ(2) in silicon. Presently, there exists a significant discrepancy in the literature between the theoretical and experimentally measured values. We present a simple theoretical model that produces result consistent with prior theoretical works and use this model to identify possible reasons for this discrepancy.

  6. Hereditary periodic fever syndromes

    NARCIS (Netherlands)

    McDermott, MF; Frenkel, J

    Hereditary periodic fever syndromes are defined by recurrent attacks of generalised inflammation for which no infectious or auto-immune cause can be identified. For most of these disorders, the molecular basis has recently been elucidated. This has opened the prospect of novel therapeutic

  7. Almost periodic Schroedinger operators

    International Nuclear Information System (INIS)

    Bellissard, J.; Lima, R.

    1984-01-01

    These lectures are devoted to recent developments in the theory of almost-periodic Schroedinger Operators. We specially describe the algebraic point of view, with applications to gap-labelling theorems. Particular models are also presented which exhibit various spectral properties. (orig.)

  8. Astrophysical implications of periodicity

    International Nuclear Information System (INIS)

    Muller, R.A.

    1988-01-01

    Two remarkable discoveries of the last decade have profound implications for astrophysics and for geophysics. These are the discovery by Alvarez et al., that certain mass extinctions are caused by the impact on the earth of a large asteroid or comet, and the discovery by Raup and Sepkoski that such extinctions are periodic, with a cycle time of 26 to 30 million years. The validity of both of these discoveries is assumed and the implications are examined. Most of the phenomena described depend not on periodicity, but just on the weaker assumption that the impacts on the earth take place primarily in showers. Proposed explanations for the periodicity include galactic oscillations, the Planet X model, and the possibility of Nemesis, a solar companion star. These hypotheses are critically examined. Results of the search for the solar companion are reported. The Deccan flood basalts of India have been proposed as the impact site for the Cretaceous impact, but this hypotheisis is in contradiction with the conclusion of Courtillot et al., that the magma flow began during a period of normal magnetic field. A possible resolution of this contradiction is proposed

  9. Periodic Table of Students.

    Science.gov (United States)

    Johnson, Mike

    1998-01-01

    Presents an exercise in which an eighth-grade science teacher decorated the classroom with a periodic table of students. Student photographs were arranged according to similarities into vertical columns. Students were each assigned an atomic number according to their placement in the table. The table is then used to teach students about…

  10. A Modern Periodic Table.

    Science.gov (United States)

    Herrenden-Harker, B. D.

    1997-01-01

    Presents a modern Periodic Table based on the electron distribution in the outermost shell and the order of filling of the sublevels within the shells. Enables a student to read off directly the electronic configuration of the element and the order in which filling occurs. (JRH)

  11. Study of a device for the direct measurement of the fission gas pressure inside an in-pile fuel element; Etude d'un dispositif pour la mesure directe de la pression des gaz de fission a l'interieur d'un element combustible en pile

    Energy Technology Data Exchange (ETDEWEB)

    Lavaud, B; Uschanoff, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The fission gas pressure inside a fuel element made of a refractory fuel constitutes an important limiting factor for the burn-up. Although it is possible to calculate approximately the volume of gas produced outside the fuel during its life-time; it is nevertheless very difficult to evaluate the pressure since the volume allowed to the fission gases, as well as their temperature are known only very approximately. This physical value, which is essential for the technologist, can only be known by direct in-pile measurement of the pressure. The report describes the equipment which has been developed for this test. (authors) [French] La pression des gaz de fission a l'interieur d'un element combustible a combustible refractaire constitue une des limitations importantes du taux de combustion. Si on peut approcher par calcul la determination du volume, des gaz degages hors du combustible au cours de sa vie, il est par contre tres difficile d'evaluer la pression car le volume alloue aux gaz de fission et leur temperature sont tres mal connus. Cette donnee essentielle pour le technologue ne peut etre atteinte que par une mesure directe en pile de la pression. Le rapport decrit l'appareillage qui a ete mis au point pour cet essai. (auteurs)

  12. Algeria facing the challenges of Europe natural gas supply and the respect of the environment.; L'Algerie face aux defis de l'approvisionnement de l'Europe en gaz naturel et le respect de l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Nadia Nait

    2010-09-15

    Taking into account the expectations, for the next decades, of a strong increase in the demand for gas in Europe, Algeria has committed to large structuring projects, adding to the two gas pipeline linking Algeria to Spain via Morocco and Algeria to Italy via Tunisia. Two more undertakings are added linking Algeria directly to two European partners. Sonatrach will play an important role in global environment protection, natural gas being less polluting than oil and coal and emitting less co2. Substitution of coal by natural gas will generate socio economical advantages and will preserve the environment. [French] Compte tenu des attentes, pour les decennies prochaines, d'une forte croissance de la demande de gaz en Europe, l'Algerie s'est engagee dans de grands projet structurants s'ajoutant aux deux gazoducs reliant l'Algerie a l'Espagne via le Maroc et l'Algerie a l'Italie via la Tunisie, viennent s'ajouter deux autres ouvrages reliant directement l'Algerie a deux partenaires europeens. Sonatrach Jouera un role important dans la protection de l'environnement a l'echelle mondiale, le gaz naturel est moins polluants que le petrole, le charbon et emet moins de co2. La substitution du charbon par le gaz naturel generera des avantages socio-economiques, preservation de l'environnement.

  13. Thyrotoxic periodic paralysis

    International Nuclear Information System (INIS)

    Ferreiro, J.E.; Arguelles, D.J.; Rams, H. Jr.

    1986-01-01

    A case of thyrotoxic periodic paralysis is reported in a Hispanic man with an unusual recurrence six weeks after radioactive iodine treatment. Thyrotoxic periodic paralysis has now been well characterized in the literature: it occurs primarily in Orientals with an overwhelming male preponderance and a higher association of specific HLA antigens. Clinical manifestations include onset after high carbohydrate ingestion or heavy exertion, with progressive symmetric weakness leading to flaccid paralysis of the extremities and other muscle groups, lasting several hours. If hypokalemia is present, potassium administration may help abort the attack. Although propranolol can be efficacious in preventing further episodes, the only definitive treatment is establishing a euthyroid state. The pathophysiology is still controversial, but reflects altered potassium and calcium dynamics as well as certain morphologic characteristics within the muscle unit itself

  14. Polysheroidal periodic functions

    International Nuclear Information System (INIS)

    Truskova, N.F.

    1985-01-01

    Separation of variables in the Helmholtz N-dimensional (N≥4) equation in polyspheroidal coordinate systems leads to the necessity of solving equations going over into equations for polyspheroidal periodic functions used for solving the two-centre problem in quantum mechanics, the three-body problem with Coulomb interaction, etc. For these functions the expansions are derived in terms of the Jacobi polynomials and Bessel functions. Their basic properties, asymptotics are considered. The algorithm of their computer calculations is developed. The results of numerical calculations are given

  15. Deciphering Periodic Methanol Masers

    Science.gov (United States)

    Stecklum, Bringfried; Caratti o Garatti, Alessio; Henning, Thomas; Hodapp, Klaus; Hopp, Ulrich; Kraus, Alex; Linz, Hendrik; Sanna, Alberto; Sobolev, Andrej; Wolf, Verena

    2018-05-01

    Impressive progress has been made in recent years on massive star formation, yet the involved high optical depths even at submm/mm wavelengths make it difficult to reveal its details. Recently, accretion bursts of massive YSOs have been identified to cause flares of Class II methanol masers (methanol masers for short) due to enhanced mid-IR pumping. This opens a new window to protostellar accretion variability, and implies that periodic methanol masers hint at cyclic accretion. Pinning down the cause of the periodicity requires joint IR and radio monitoring. We derived the first IR light curve of a periodic maser host from NEOWISE data. The source, G107.298+5.639, is an intermediate-mass YSO hosting methanol and water masers which flare every 34.5 days. Our recent joint K-band and radio observations yielded first but marginal evidence for a phase lag between the rise of IR and maser emission, respectively, and revealed that both NEOWISE and K-band light curves are strongly affected by the light echo from the ambient dust. Both the superior resolution of IRAC over NEOWISE and the longer wavelengths compared to our ground-based imaging are required to inhibit the distractive contamination by the light echo. Thus, we ask for IRAC monitoring of G107 to cover one flare cycle, in tandem with 100-m Effelsberg and 2-m Wendelstein radio and NIR observations to obtain the first high-quality synoptic measurements of this kind of sources. The IR-maser phase lag, the intrinsic shape of the IR light curves and their possible color variation during the cycle allow us to constrain models for the periodic maser excitation. Since methanol masers are signposts of intermediate-mass and massive YSOs, deciphering their variability offers a clue to the dynamics of the accretion-mediated growth of massive stars and their feedback onto the immediate natal environment. The Spitzer light curve of such a maser-hosting YSO would be a legacy science product of the mission.

  16. Méthode analytique généralisée pour le calcul du coning. Nouvelle solution pour calculer le coning de gaz, d'eau et double coning dans les puits verticaux et horizontaux Generalized Analytical Method for Coning Calculation. New Solution to Calculation Both the Gas Coning, Water Coning and Dual Coning for Vertical and Horizontal Wells

    Directory of Open Access Journals (Sweden)

    Pietraru V.

    2006-11-01

    Full Text Available Une nouvelle méthode analytique d'évaluation du coning d'eau par bottom water drive et/ou de gaz par gas-cap drive dans les puits horizontaux et verticaux a été développée pour les réservoirs infinis [1]. Dans cet article, une généralisation de cette méthode est présentée pour les réservoirs confinés d'extension limitée dont le toit est horizontal. La généralisation proposée est basée sur la résolution des équations différentielles de la diffusivité avec prise en compte des effets de drainage par gravité et des conditions aux limites pour un réservoir confiné. La méthode est applicable aux réservoirs isotropes ou anisotropes. L'hypothèse de pression constante à la limite de l'aire de drainage dans l'eau et/ou dans le gaz a été adoptée. Les pertes de charge dans l'aquifère et dans le gas-cap sont donc négligées. Les principales contributions de cet article sont : - L'introduction de la notion de rayon de cône, différent du rayon de puits. La hauteur du cône et le débit critique dépendent du rayon de cône alors qu'ils sont indépendants du rayon du puits. - Une nouvelle corrélation pour le calcul du débit critique sous forme adimensionnelle en fonction de trois paramètres : le temps, la longueur du drain horizontal (nulle pour un puits vertical et le rayon de drainage. - Des corrélations pour le calcul du rapport des débits gaz/huile (GOR ou de la fraction en eau (fw, pendant les périodes critique et postcritique, qui tiennent compte de la pression capillaire et des perméabilités relatives. - Des corrélations pour le calcul des rapports de débits gaz/huile et eau/huile pendant les périodes pré, post et supercritique en double coning. - Des critères pour le calcul du temps de percée au puits en simple coning de gaz ou d'eau, ou en double coning de gaz et d'eau. A new analytical method for assessing water and/or gas coning in horizontal and vertical wells has been developed for infinite

  17. Performance Analysis of Compositional and Modified Black-Oil Models For a Gas Lift Process Analyse des performances de modèles black-oil pour le procédé d’extraction par injection de gaz

    Directory of Open Access Journals (Sweden)

    Mahmudi M.

    2013-03-01

    Full Text Available Artificial gas lift is frequently used to boost production rate of mature oil fields. An integrated mathematical model was developed in order to track the spatial and temporal changes in various components of the continuous gas lift process. The computational demand for solving the comprehensive gas lift model highly depends on the thermodynamic treatment of the hydrocarbon fluids involved. A full compositional treatment using an equation of state provides the most accurate results but at a high computational cost. The results of this article showed that the computational cost can be halved without sacrificing accuracy by using reduced parameter stability and flash calculation procedures. It was also demonstrated that a Modified Black-Oil treatment of the fluids can provide reasonable accuracy at a much-reduced computational cost. The Modified Black-Oil treatment provides a valuable tool when the model has to be solved many hundreds of times to find the optimal combination of the gas lift parameters. Les procédés artificiels d’extraction par injection de gaz sont utilisés pour améliorer le taux de récupération des champs pétroliers matures. Un modèle mathématique intégré a été développé pour détecter de faibles changements temporels et spatiaux dans plusieurs composants des procédés continus d’extraction par injection de gaz. La solution numérique utilisée pour résoudre le modèle du procédé d’extraction dépend fortement du comportement thermodynamique des hydrocarbures impliqués. Un traitement complet de la composition utilisant une équation d’état offre les résultats les plus précis, mais à un coût de calcul très élevé. Les résultats de nos travaux de recherche montrent que l’implication des paramètres de stabilité et des procédures de calcul flash, peut diviser par deux le coût du calcul tout en gardant la précision attendue. Ces travaux montrent que la précision admissible peut être

  18. Periodically modulated dark states

    Science.gov (United States)

    Han, Yingying; Zhang, Jun; Zhang, Wenxian

    2018-04-01

    Phenomena of electromagnetically induced transparency (PEIT) may be interpreted by the Autler-Townes Splitting (ATS), where the coupled states are split by the coupling laser field, or by the quantum destructive interference (QDI), where the atomic phases caused by the coupling laser and the probe laser field cancel. We propose modulated experiments to explore the PEIT in an alternative way by periodically modulating the coupling and the probe fields in a Λ-type three-level system initially in a dark state. Our analytical and numerical results rule out the ATS interpretation and show that the QDI interpretation is more appropriate for the modulated experiments. Interestingly, dark state persists in the double-modulation situation where control and probe fields never occur simultaneously, which is significant difference from the traditional dark state condition. The proposed experiments are readily implemented in atomic gases, artificial atoms in superconducting quantum devices, or three-level meta-atoms in meta-materials.

  19. Construction of the core of the 'heavy water-gas' reactor EL 4; Structures du coeur du reacteur 'eau- lourde-gaz EL 4'

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, J L; Foulquier, H; Thome, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    problem of thermal insulation around a zirconium alloy liner tube. The neutron absorption equivalent is about 1, 1 mm of Al, and the mean loss around 2 p. 100 of the thermal power of the reactor. The methods proposed have proved practicable as a result of important research and developments on automatic remote control for all the operations which make up the sequences of mounting, demounting and repairing of the construction components. In particular the possibilities opened up by the new techniques of welding tubes from the inside have been extended to other problems connected with the assembling of a reactor. (authors) [French] Le coeur de ce reacteur est constitue par une cuve contenant l'eau lourde, cuve traversee d'une serie de tubes de force dans lesquels circule le gaz caloporteur sous pression de 60 at. Les specifications de depart qui ont joue un role important dans la conception de ces structures concernent des aspects de securite de fonctionnement (chargement du combustible par les deux faces du reacteur, remplacement des structures sur les deux faces du reacteur), des necessites neutroniques (absorption des structures minimum, pas du reseau, diametre des tubes de force) et des considerations thermiques (temperature de sortie 500 C). Ces specifications ont entraine une disposition horizontale des tubes de force et des problemes d'encombrement tres delicats qui ont elimine (pour les dimensions d'EL 4) toute possibilite de recourir a des compensateurs de dilatation sur les tubes de force. II s'ensuit un dessin de cuve semi-rigide dans lequel les tubes de force contribuent pour une part importante a la resistance mecanique de l'ensemble en jouant le role de tirant, d'ou des contraintes elevees sur les jonctions et tubes de force (et le choix des alliages de zirconium). Les structures comprennent le tube de force, les jonctions, l'isolement thermique et le tube de guidage. On expose brievement les moyens d'essais mis en oeuvre et les performances de ces diverses

  20. Improvement of heat transfer to gases by mean of electric fields (1962); Etude de l'amelioration des echanges de chaleur dans les gaz au moyen de champs electriques (1962)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1962-07-01

    The effects of electric fields on heat transfer to the following gases: air, argon, nitrogen, carbon dioxyde, helium, hydrogen, were studied in an annular channel, the inner part of which is the heating element. Experiments were made both in free convection and forced convection, the latter case with and without an external source of ionisation. Two causes of improvement of heat transfer were found: electro-convection and ionic convection; the influence of various parameters (electric fields, current of ionisation, temperatures, pressures, flow rate, etc...) is also investigated. Increasing of exchanged power was measured: in free convection this increasing reached 400 per cent and, in forced convection, it was found to be mainly dependent on stream velocity, decreasing from 300 per cent at Re = 6000 to few per cent for Re {>=} 30000 for a given gas pressure. Experiments in pile have shown that the use of an external source of ionisation allowed to obtain the same order of improvement as above but with a voltage much lower. This fact would make easier the use of this process of heat transfer in a channel of a reactor. (authors) [French] On a etudie l'action du champ electrique sur les echanges de chaleur dans les gaz suivants: air, argon, azote, anhydride carbonique, helium, hydrogene, avec un element chauffant cylindrique dans un canal concentrique. Des experiences ont ete effectuees en convection libre et en convection forcee en l'absence et en presence d'une source exterieure d'ionisation. On a distingue deux sortes de mecanismes d'accroissement des echanges, l'un d'electroconvection proprement dite et l'autre de convection ionique, et on precise l'influence des divers parametres (champ electrique, courant d'ionisation, temperature, pression, debit, etc...). On a pu chiffrer les ordres de grandeur des accroissements d'echanges observes qui, en convection libre, atteignent 300 a 400 pour cent et, en convection forcee, dependent beaucoup de la vitesse d

  1. Contribution to the study of the reactivity of graphite with respect to carbon dioxide and air; Contribution a l'etude de la reactivite du graphite vis-a-vis du gaz corbonique et de l'air

    Energy Technology Data Exchange (ETDEWEB)

    Jacquet, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-09-15

    The oxidation of nuclear-quality graphite by air and carbon dioxide has been studied at temperatures at which the reaction becomes measurable. These experiments have been carried out on graphites differing in the concentration and nature of their ash, and in their mode of preparation. The reaction velocities measured have been compared in an attempt to correlate these two factors. Ten types of graphite have thus been studied. Since the oxidation reactions are of the type gas-solid, their velocities have also been compared to the BET surface areas of the graphite studied and to the diameter distribution of the pores of this surface. The conclusion is that, even for these low impurity contents, the law relating the reaction velocity to the surface is masked by the impurities which appear to behave as preferential reaction sites. This has been shown by carrying out successive purifications on various types of graphite, which treatment results in an important decrease in the reactivity of all the samples studied. (author) [French] On a etudie l'oxydation de graphites de qualites nucleaires par l'air et par le gaz carbonique, a des temperatures telles que la reaction commence a etre mesurable. Ces essais ont porte sur des graphites differents aux points de vue de la concentration et de la nature des cendres, et differents par le mode de preparation. Les vitesses de reaction mesurees ont ete comparees afin de tenter de les relier a ces deux facteurs. Dix qualites de graphite ont ainsi ete etudiees. Les reactions d'oxydation etant des reactions gaz-solide, les vitesses ont ete egalement comparees aux surfaces specifiques B.E.T. des echantillons de graphite etudies et a la repartition par diametres des pores de cette surface. La conclusion est que, meme a ces teneurs faibles en impuretes, la loi de variation de la vitesse de reaction en fonction de la surface est masquee par les impuretes qui paraissent jouer le role de sites privilegies de reaction comme l'ont montre les

  2. Possibilities of gas-phase radio-chromatography application to permanent-gas analysis; Possibilites de la radiochromatographie en phase gazeuse applications a l'analyse des gaz permanents

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, M C; Charrier, G; Alba, C; Massimino, D [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1970-07-01

    The gas-phase radio-chromatography technique has been applied to the rapid analysis of permanent gases (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) labelled with radioactive indicators ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). After calibration, the components of such a mixture can be identified and their concentrations measured in less than two hours, using a sample volume of from 0.1 to 10 cm{sup 3}. The minimum detectable activity is of the order of 10{sup -4} {mu}C for each radioactive isotope. The measurements are reproducible to about 2 to 3 per cent. This work has been mainly concerned with the influence of parameters affecting the response of the radioactivity detector (ionization chamber or gas flow proportional counter). The method has very numerous applications both theoretically, for the study of chromatographic phenomena under ideal conditions (infinitesimal concentrations made possible by the use of radioactive tracers), and practically, for rapid and accurate radiochemical analysis of radioactive gas mixtures. (authors) [French] La technique de radiochromatographie en phase gazeuse est appliquee a l'analyse rapide de gaz permanents (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) marques par des indicateurs radioactifs ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). Apres etalonnage, l'identification et la mesure des concentrations des constituants d'un tel melange requierent moins de deux heures, sur un volume d'echantillon de 0.1 a 10 cm{sup 3}. L'activite minimum detectable est de l'ordre de 10{sup -4} {mu}C pour chaque isotope radioactif. La reproductibilite des mesures est de l'ordre de 2 a 3 pour cent. L'etude porte principalement sur l'influence des parametres affectant la reponse du detecteur de radioactivite (chambre d'ionisation, ou compteur proportionnel a circulation). La methode est extremement fertile en applications tant sur le plan theorique pour l'etude du phenomene chromatographique dans les conditions

  3. Measurement of the activity of beta emitting gases using an ionisation chamber; Mesure de l'activite des gaz emetteurs beta au moyen d'une chambre d'ionisation

    Energy Technology Data Exchange (ETDEWEB)

    Lebouleux, P [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1962-07-01

    An ionization chamber was developed for measuring directly the activity of a {beta}-emitting gas whatever the gas may be. The following two parameters are defined and determined: p, the average specific ionization produced by a {beta} disintegration, and i, the average {beta} path in the chamber. It was shown, during the determination of i, that the {beta} particles are reflected on the walls of the ionization chamber when the latter are made of a high atomic number material. It was possible to eliminate this effect by constructing an electrode chamber made of graphite. With this chamber a direct measurement can be made of the activity of a gaseous {beta} emitter with a precision of about {+-}10%. Some applications are given of the graphite electrode chamber (calibration of the chambers built industrially and determination of the activation cross section of a gaseous emitter). It was possible to determine the activation cross section of {sup 134}Xe; a value of 0.18 {+-} 0.03 barn was found. (author) [French] Le but de l'etude est de realiser une chambre d'ionisation permettant d'effectuer une mesure directe de l'activite d'un gaz emetteur {beta} quel que soit l'emetteur considere. On definit et l'on determine les deux parametres suivants: p: ionisation specifique moyenne produite par une desintegration {beta}. La determination est effectuee par une methode graphique, i: moyenne des parcours des {beta} dans la chambre. La determination est effectuee experimentalement par introduction dans la chambre d'un gaz radioactif dont on peut calculer l'activite. On a mis en evidence, au cours de la determination de i, la reflexion des particules {beta} sur les parois des chambres d'ionisation lorsque celles-ci sont constituees d'un materiau de numero atomique eleve. La construction d'une chambre a electrodes de graphite nous a permis d'eliminer ce phenomene. Avec cette chambre, on effectue une mesure directe de l'activite d'un emetteur {beta} gazeux avec une precision de l

  4. Possibilities of gas-phase radio-chromatography application to permanent-gas analysis; Possibilites de la radiochromatographie en phase gazeuse applications a l'analyse des gaz permanents

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, M.C.; Charrier, G.; Alba, C.; Massimino, D. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1970-07-01

    The gas-phase radio-chromatography technique has been applied to the rapid analysis of permanent gases (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) labelled with radioactive indicators ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). After calibration, the components of such a mixture can be identified and their concentrations measured in less than two hours, using a sample volume of from 0.1 to 10 cm{sup 3}. The minimum detectable activity is of the order of 10{sup -4} {mu}C for each radioactive isotope. The measurements are reproducible to about 2 to 3 per cent. This work has been mainly concerned with the influence of parameters affecting the response of the radioactivity detector (ionization chamber or gas flow proportional counter). The method has very numerous applications both theoretically, for the study of chromatographic phenomena under ideal conditions (infinitesimal concentrations made possible by the use of radioactive tracers), and practically, for rapid and accurate radiochemical analysis of radioactive gas mixtures. (authors) [French] La technique de radiochromatographie en phase gazeuse est appliquee a l'analyse rapide de gaz permanents (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) marques par des indicateurs radioactifs ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). Apres etalonnage, l'identification et la mesure des concentrations des constituants d'un tel melange requierent moins de deux heures, sur un volume d'echantillon de 0.1 a 10 cm{sup 3}. L'activite minimum detectable est de l'ordre de 10{sup -4} {mu}C pour chaque isotope radioactif. La reproductibilite des mesures est de l'ordre de 2 a 3 pour cent. L'etude porte principalement sur l'influence des parametres affectant la reponse du detecteur de radioactivite (chambre d'ionisation, ou compteur proportionnel a circulation). La methode est extremement fertile en applications tant sur le plan theorique pour l

  5. [Childhood periodic syndromes].

    Science.gov (United States)

    Cuvellier, J-C; Lépine, A

    2010-01-01

    This review focuses on the so-called "periodic syndromes of childhood that are precursors to migraine", as included in the Second Edition of the International Classification of Headache Disorders. Three periodic syndromes of childhood are included in the Second Edition of the International Classification of Headache Disorders: abdominal migraine, cyclic vomiting syndrome and benign paroxysmal vertigo, and a fourth, benign paroxysmal torticollis is presented in the Appendix. The key clinical features of this group of disorders are the episodic pattern and intervals of complete health. Episodes of benign paroxysmal torticollis begin between 2 and 8 months of age. Attacks are characterized by an abnormal inclination and/or rotation of the head to one side, due to cervical dystonia. They usually resolve by 5 years. Benign paroxysmal vertigo presents as sudden attacks of vertigo, accompanied by inability to stand without support, and lasting seconds to minutes. Age at onset is between 2 and 4 years, and the symptoms disappear by the age of 5. Cyclic vomiting syndrome is characterized in young infants and children by repeated stereotyped episodes of pernicious vomiting, at times to the point of dehydration, and impacting quality of life. Mean age of onset is 5 years. Abdominal migraine remains a controversial issue and presents in childhood with repeated stereotyped episodes of unexplained abdominal pain, nausea and vomiting occurring in the absence of headache. Mean age of onset is 7 years. Both cyclic vomiting syndrome and abdominal migraine are noted for the absence of pathognomonic clinical features but also for the large number of other conditions to be considered in their differential diagnoses. Diagnostic criteria, such as those of the Second Edition of the International Classification of Headache Disorders and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition, have made diagnostic approach and management easier. Their diagnosis

  6. Nonparametric Inference for Periodic Sequences

    KAUST Repository

    Sun, Ying; Hart, Jeffrey D.; Genton, Marc G.

    2012-01-01

    the periodogram, a widely used tool for period estimation. The CV method is computationally simple and implicitly penalizes multiples of the smallest period, leading to a "virtually" consistent estimator of integer periods. This estimator is investigated both

  7. Eskişehir’de Hava Kirliliği ve Doğal Gazın Tarihçesi: Genel Değerlendirme / History of Air Pollution and Natural Gas Usage in Eskişehir: A General Review

    Directory of Open Access Journals (Sweden)

    Nazmi Oruç

    2012-12-01

    şehir temiz hava planı (2011-2014 hazırlanmıştır. Partikül Madde ve SO2 yanında NO2,O3 ve PAH gibi kirleticilerin ve ulaşım araçlarının neden olduğu kirliliğin de irdelendiği bu raporda, Eskişehir için ulusal yasal sınır değerleri zorlayan bir durum söz konusu olmasa da geniş ölçekte Avrupa Birliği ve Dünya Sağlık Örgütü (DSÖ gibi kuruluşların oluşturmuş olduğu standartların üzerinde değerlere rastlandığı kaydedilmektedir. Hava kirliliğinin önlenmesi amacıyla doğal gaz kullanımına ilk kez Eskişehir Organize Sanayi Bölgesinde (EOSB Botaş bünyesinde 1990 yılında başlanılmış daha sonra bu hizmet özelleştirme kapsamı içerisinde 2004 yılında Eskişehir Doğal Gaz Dağıtım A.Ş. (ESGAZ firmasına devredilmiştir. ESGAZ, Büyükşehir Belediyesi mücavir alanlarda yer alan imara açık tüm cadde ve sokaklara doğal gaz hizmeti vermekte olup 2004 yılında devir alınan 107.000 bağımsız birim sayısını 2011 yılı sonu itibariyle 300.000’e çıkartmıştır. EOSB bölgesi hariç evsel ve şehir içi sanayi tüketimi de 2005 yılında 211.756.888 m3 iken, 2011 yılında 348.974.147 m3’e çıkmıştır. Tüm bu olumlu gelişmelere karşın doğal gaz alt yapısı bulunan bazı semt ve apartmanlarda günümüzde de ithal ve yerli kömür kullanılması zaman zaman hava kirliliğine neden olmaktadır. İlk aşamada kent merkezinde özellikle kış aylarında kömür yerine tamamen doğal gaza geçilmesi ve ulaşım kaynaklı hava kirliğinin azaltılması için gereken önlemlerin alınması önerilmiştir. History of Air Pollution and Natural Gas Usage in Eskişehir: A General Review The aim of this study is to investigate the use of natural gas and air pollution levels in Eskişehir City Center in the last 30 years. Air pollution has been phenomena in Eskişehir since the beginning of 1980s, due to the use of low quality coal, unplanned and irregular urbanization and negative climate factors. First air

  8. Vibrational and cascade dissociation of H{sub 2}{sup +} ions by collision with gas molecules; Dissociation vibrationnelle et dissociation en cascade d'ions H{sub 2}{sup +} par collisions avec les molecules d'un gaz

    Energy Technology Data Exchange (ETDEWEB)

    Verveer, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1966-07-01

    Protons produced by collisional dissociation of H{sub 2}{sup +} ions have an energy spectrum with a narrow central peak. For a part the protons in this peak are produced by vibrational dissociation and for another part by a cascade of two collisions. For H{sub 2}{sup +} ions of 50 to 150 keV the cross section for vibrational dissociation is about 4.1 10{sup -19} cm{sup 2}/molecule in hydrogen and 1.1 10{sup -18} cm{sup 2}/molecule in argon. (author) [French] Les protons resultant de la dissociation par collisions d'ions H{sub 2}{sup +} dans un gaz ont un spectre d'energie qui presente un pic central tres etroit. Les protons dans ce pic proviennent, pour une part de la dissociation vibrationnelle et pour l'autre part d'une suite de deux collisions. Dans le domaine d'energie des ions H{sub 2}{sup +} de 50 a 150 keV la section efficace de dissociation vibrationnel vaut 4.1 10{sup -19} cm{sup 2}/molecule pour l'hydrogene et 1,1 10{sup -18} cm{sup 2}/molecule pour l'argon.

  9. Methods for continuous or semi-continuous analysis of gases dissolved in pressurized water; Methodes d'analyses continue et semi-continue de gaz dissous dans l'eau surpressee

    Energy Technology Data Exchange (ETDEWEB)

    Vignet, P; Gabilly, R; Lutz, J; Zermizogilou, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    }/kg of water. (authors) [French] Trois appareils ont ete mis au point pour permettre la mesure de gaz en solution dans l'eau sous une pression pouvant atteindre 200 kg/cm{sup 2}. 1 - Analyseur d'hydrogene: On mesure la variation relative de resistance d'un filament immerge dans l'eau, constitue par du palladium pur ou par un alliage palladium-platine 75.25, lors de l'absorption de l'hydrogene. On a trace les courbes d'etalonnage pour un fil de palladium pour des temperatures allant de 180 a 280 deg. C. A temperature ambiante, on a utilise un ruban en alliage palladium-platine. L'etude theorique et experimentale de la cinetique d'absorption de l'hydrogene dissous dans l'eau par un metal a permis de definir les meilleures conditions de fonctionnement de l'analyseur pour obtenir une reponse rapide, de l'ordre de quelques minutes. On utilise actuellement pour la mesure un pont alimente en courant alternatif (pont de Kohlrausch) avec compensation de temperature et systeme de regeneration periodique du filament. 2 - Analyseur d'oxygene: On sait que l'oxygene dissous dans l'eau reagit sur le thallium pour former l'hydroxyde de thallium, compose soluble dont la presence augmente la conductibilite electrique de l'eau. Pour realiser une methode de dosage basee sur ce principe, on a mis au point un conductimetre differentiel dont les caracteristiques permettent d'atteindre une excellente precision dans une gamme de 0,001 ppm a quelques dizaines de ppm d'oxygene. On examine dans quelles conditions le bruit de fond de l'appareil, du a des reactions parasites, peut etre rendu negligeable; puis on etudie la cinetique de la reaction d'oxydation du thallium par l'oxygene dissous, qui est de type diffusionnel. On a ainsi pu relier quantitativement le taux de transformation aux parametres physiques et hydrodynamiques. 3 - Analyse globale des gaz en solution: On isole, dans une bombe placee en derivation sur un circuit surpresse un volume d'eau a pression et temperature elevees. Apres

  10. Comportment of various magnesium alloys in carbon dioxide under pressure, between 400 and 600 deg; Compatibilite de divers alliages de magnesium avec le gaz carbonique sous pression entre 400 et 600 deg

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R; Baque, P; Chevilliard, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    'magnesium oxyde fritte'. Les echantillons, preleves dans des produits files, sont convenablement polis, deux etats de surface reproductibles etant realises a titre comparatif. Les essais ont ete effectues dans le gaz carbonique purifie, aux pressions de 25 et 60 atmospheres, et a des temperatures allant de 400 a 600, au moyen d'autoclaves speciaux en acier inoxydable, chauffes exterieurement. Leur duree est en general superieure a 1000 heures. Les equations des courbes d'augmentation de poids obtenues sont du type ({delta}p){sup n} = k.t (({delta}p en mg/cm{sup 2} et t en heures), l'exposant n etant voisin de 2, du moins jusqu'a 500 deg. C. En se referant a des resultats precedemment acquis quant a certains de ces materiaux exposes dans le gaz carbonique sous pression atmospherique et sous 15 atmospheres, il apparait que: 1) Pour un materiau determine: - a une pression donnee, l'oxydation augmente avec la temperature, - a une temperature donnee, l'oxydation augmente avec la pression, - dans les memes conditions de temperature et de pression, les resultats obtenus varient peu suivant les deux etats de surface etudies; 2) les alliages Mg-Zr presentent une resistance a l'oxydation amelioree par rapport au magnesium non allie; 3) l'alliage magnox est beaucoup moins avantageux dans le gaz carbonique que dans l'air, par rapport aux autres alliages. D'une facon generale, les courbes d'oxydation tendant vers un palier apres un certain temps d'exposition, la compatibilite de tous les alliages consideres avec le gaz carbonique apparait satisfaisante jusqu'a une temperature voisine de 500 deg. C, dans les conditions operatoires presentement definies; au dessus de 500 deg. C, des differences notables apparaissent entre les divers alliages, mais des phenomenes de sublimation interferent avec ceux d'oxydation, de sorte qu'un classement des divers materiaux ne peut etre base que sur leur resultante. (auteur)

  11. Development of a unified sizing method for gas radiation heating facilities used in large-volume buildings; Developpement d'une methode de dimensionnement unifiee d'installations de chauffage radiant gaz pour les batiments de grand volume

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, M.; Bego, L.; Douls, Y.; Le Dean, P.; Paradowski, V. [Gaz de France, GDF, Dir. de la Recherche, 75 - Paris (France)

    2000-07-01

    Builders now have perfect command of the natural gas heating technique used for large-volume buildings. However, the sizing of heating facilities still leaves grounds for discussion, whatever the energies actually used. Accordingly, between 1997 and 1999, the ATG (technical association of the Gas industry in France), seven French manufacturers of 'large volume' heating equipment, the Chaleur Et Rayonnement (CER) association and Gaz de France decided to collaborate and develop a 'unified sizing method' for heating facilities using radiating emitters. During the first year of the study, the above partners worked on the said method (theoretical thermal study of the radiative phenomena, and then adaptation to the methods currently used by the various manufacturers). In 1998, with the support of the ADEME (the French environment and energy control agency), the partners tested the method on five industrial buildings (studying the thermal behavior and making air renewal measurements with search gases). This work made it possible to either confirm or adapt the theoretical evaluations which had been made originally. In 1999, a software program was produced to make the developed method more user friendly. The program can be used to determine the power to be installed, but also to assess the quality of the chosen configuration of the emitters (unit power, inclination, orientation) for optimum customer comfort. (authors)

  12. Testing periodically integrated autoregressive models

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); M.J. McAleer (Michael)

    1997-01-01

    textabstractPeriodically integrated time series require a periodic differencing filter to remove the stochastic trend. A non-periodic integrated time series needs the first-difference filter for similar reasons. When the changing seasonal fluctuations for the non-periodic integrated series can be

  13. Periodic feedback stabilization for linear periodic evolution equations

    CERN Document Server

    Wang, Gengsheng

    2016-01-01

    This book introduces a number of recent advances regarding periodic feedback stabilization for linear and time periodic evolution equations. First, it presents selected connections between linear quadratic optimal control theory and feedback stabilization theory for linear periodic evolution equations. Secondly, it identifies several criteria for the periodic feedback stabilization from the perspective of geometry, algebra and analyses respectively. Next, it describes several ways to design periodic feedback laws. Lastly, the book introduces readers to key methods for designing the control machines. Given its coverage and scope, it offers a helpful guide for graduate students and researchers in the areas of control theory and applied mathematics.

  14. Tariff proposal of the Commission of energy regulation from February 28, 2008 for the use of public natural gas distribution networks; Proposition tarifaire de la Commission de regulation de l'energie du 28 fevrier 2008 pour l'utilisation des reseaux publics de distribution de gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    With the complete opening of natural gas markets to competition and the legal separation of distribution networks, Gaz de France Reseau Distribution requested the implementation of a new tariff of use of gas distribution networks to the Commission of energy regulation (CRE). A new tariff of networks utilisation has thus been proposed by CRE after a public consultation and the audition of gas suppliers. This tariff foresees a 5.6% increase of the present day tariff by July 1, 2008. The impact on the end-users' gas retail price will be a 1.5% rise of the regulated tariff. (J.S.)

  15. Study of the strength of the internal can for internally and externally cooled fuel elements intended for gas graphite reactors; Etude de la tenue de la gaine interne pour-element combustible a refroidissement interne et externe d'un reacteur graphite-gaz

    Energy Technology Data Exchange (ETDEWEB)

    Boudouresque, B; Courcon, P; Lestiboubois, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The cartridge of an internally and externally cooled annular fuel element used in gas-graphite reactors is made up of an uranium fuel tube, an external can and an internal can made of magnesium alloy. For the thermal exchange between the internal can and the fuel to be satisfactory, it is necessary for the can to stay in contact with the uranium under all temperature conditions. This report, based on a theoretical study, shows how the internal can fuel gap varies during the processes of canning, charging into the reactor and thermal cycling. The following parameters are considered: tube diameter, pressure of the heat carrying gas, gas entry temperature, plasticity of the can alloy. It is shown that for all operating conditions the internal can of a 77 x 95 element, planned for a gas-graphite reactor with a 40 kg/cm{sup 2} gas pressure, should remain in contact with the fuel. (authors) [French] La cartouche d'un element combustible annulaire, a refroidissement interne et externe pour reacteur graphite-gaz, est composee d'un tube combustible en uranium, d'une gaine externe et d'une gaine interne en alliage de magnesium. Pour que l'echange thermique entre la gaine interne et le combustible soit bon, il faut que la gaine reste appliquee sur l'uranium quel que soit le regime de temperature. Cette note a pour but de montrer comment, d'apres une etude theorique, le jeu combustible-gaine interne varie au cours des operations de gainage, de chargement dans le reacteur, et des cyclages thermiques. Les parametres suivants sont etudies: diametres de tube, pression du gaz caloporteur, temperature d'entree du gaz, plasticite de l'alliage de gaine. Il est montre que, quel que soit le regime de fonctionnement, la gaine interne d'un element 77 x 95, en projet pour un reacteur graphite-gaz sous pression de 40 kg/cm{sup 2}, doit rester appliquee sur le combustible. (auteurs)

  16. Study of the consequences of the rupture of a pressure tube in the tank of a gas-cooled, heavy-water moderated reactor; Etude des consequences de la rupture d'un tube de force dans la cuve d'un reacteur modere a l'eau lourde et refroidi au gaz

    Energy Technology Data Exchange (ETDEWEB)

    Hareux, F; Roche, R; Vrillon, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Bursting of a pressure tube in the tank of a heavy water moderated-gas cooled reactor is an accident which has been studied experimentally about EL-4. A first test (scale 1) having shown that the burst of a tube does not cause the rupture of adjacent tubes, tests on the tank resistance have been undertaken with a very reduced scale model (1 to 10). It has been found that the tank can endure many bursts of tube without any important deformation. Transient pressure in the tank is an oscillatory weakened wave, the maximum of which (pressure peak) has been the object of a particular experimental study. It appears that the most important parameters which affect the pressure peak are; the pressure of the gas included in the bursting pressure tube, the volume of this gas, the mass of air included in the tank and the nature of the gas. A general method to calculate the pressure peak value in reactor tanks has been elaborated by direct application of experimental data. (authors) [French] L'eclatement d'un tube de force dans la cuve d'un reacteur de puissance modere a l'eau lourde et refroidi par un gaz sous pression est un accident qui a ete etudie experimentalement a propos d'EL-4. Un premier essai a l'echelle 1 ayant montre que l'eclatement d'un tube ne provoque pas celui des tubes voisins, des essais relatifs a la tenue de la cuve ont ete effectues sur maquettes a echelle tres reduite (l/lO). Il a ete trouve que la cuve peut supporter plusieurs eclatements de tubes sans deformations notables. La pression transitoire dans la cuve a une allure oscillatoire amortie dont le maximum (pression de pic) a fait l'objet d'une etude experimentale detaillee. Il apparait que les parametres essentiels influant sur cette pression sont: la pression du gaz contenu dans le tube de force, le volume du gaz qui participe a l'eclatement, la flexibilite de la cuve, la masse d'air empoisonnee dans la cuve, la nature du gaz explosant. Une methode generale d'estimation des pics de pression dans

  17. The redoubtable ecological periodic table

    Science.gov (United States)

    Ecological periodic tables are repositories of reliable information on quantitative, predictably recurring (periodic) habitat–community patterns and their uncertainty, scaling and transferability. Their reliability derives from their grounding in sound ecological principle...

  18. Periodic waves in nonlinear metamaterials

    International Nuclear Information System (INIS)

    Liu, Wen-Jun; Xiao, Jing-Hua; Yan, Jie-Yun; Tian, Bo

    2012-01-01

    Periodic waves are presented in this Letter. With symbolic computation, equations for monochromatic waves are studied, and analytic periodic waves are obtained. Factors affecting properties of periodic waves are analyzed. Nonlinear metamaterials, with the continuous distribution of the dielectric permittivity obtained, are different from the ones with the discrete distribution. -- Highlights: ► Equations for the monochromatic waves in transverse magnetic polarization have been studied. ► Analytic periodic waves for the equations have been obtained. ► Periodic waves are theoretically presented and studied in the nonlinear metamaterials.

  19. Nonparametric Inference for Periodic Sequences

    KAUST Repository

    Sun, Ying

    2012-02-01

    This article proposes a nonparametric method for estimating the period and values of a periodic sequence when the data are evenly spaced in time. The period is estimated by a "leave-out-one-cycle" version of cross-validation (CV) and complements the periodogram, a widely used tool for period estimation. The CV method is computationally simple and implicitly penalizes multiples of the smallest period, leading to a "virtually" consistent estimator of integer periods. This estimator is investigated both theoretically and by simulation.We also propose a nonparametric test of the null hypothesis that the data have constantmean against the alternative that the sequence of means is periodic. Finally, our methodology is demonstrated on three well-known time series: the sunspots and lynx trapping data, and the El Niño series of sea surface temperatures. © 2012 American Statistical Association and the American Society for Quality.

  20. Positive periodic solutions of delayed periodic Lotka-Volterra systems

    International Nuclear Information System (INIS)

    Lin Wei; Chen Tianping

    2005-01-01

    In this Letter, for a general class of delayed periodic Lotka-Volterra systems, we prove some new results on the existence of positive periodic solutions by Schauder's fixed point theorem. The global asymptotical stability of positive periodic solutions is discussed further, and conditions for exponential convergence are given. The conditions we obtained are weaker than the previously known ones and can be easily reduced to several special cases

  1. Photolysis of Periodate and Periodic Acid in Aqueous Solution

    DEFF Research Database (Denmark)

    Sehested, Knud; Kläning, U. K.

    1978-01-01

    The photochemistry of periodate and periodic acid in aqueous solution was studied (i) by quantum yield measurements at low light intensity (ii) by flash photolysis, and (iii) by photolysis of glassy samples at 77 K. The photochemical studies were supplemented with pulse radiolysis studies...... of aqueous periodate solutions and with kinetic studies using stopped-flow technique. In strongly alkaline solution the photodecomposition of periodate proceeds via formation of O– and IVI. At pH solution O3 P is formed in a small...

  2. Experimental study of improvement of exchanged power in gases by catalytic dissociation: ammonia (1961); Etude experimentale de l'amelioration des echanges de chaleur avec les gaz par dissociation catalytique: ammoniac (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Perroud, P [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires; De La Harpe, A [Centre National de la Recherche Scientifique(CNRS), 75 - Paris (France)

    1961-07-01

    Rates of ammonia dissociation and resulting coefficients of improvement of exchanged power have been measured in an annular channel under following conditions: mean wall temperature until 1500 deg. C (tungsten rod, diameter 3 mm), mass velocity until 11 g/cm{sup 2}.s and absolute pressure between 1.5 and 7 kg/cm{sup 2}. Rate of dissociation is mainly function of wall temperature and total mass flow rate of ammonia; it depends little on entrance gas temperature and is practically independent of pressure. Apparent coefficients of improvement of exchanged power under above conditions (including radiation) have reached 1.8; this maximum was obtained for a mean wall temperature of 1250 deg. C. These coefficients decrease when Reynolds number increases. Finally, a theoretical analysis of the phenomenon is given as well as possibilities of application. (authors) [French] Les taux de dissociation d'ammoniac et les coefficients d'amelioration de puissance echangee resultants ont ete mesures en espace annulaire dans les conditions suivantes: temperature moyenne de paroi jusqu'a 1500 deg. C (barreau de tungstene de diametre 3 mm), vitesse massique jusqu'a 11 g/cm{sup 2}.s et pression absolue comprise entre 1,5 et 7 kg/cm{sup 2}. Le taux de dissociation est surtout fonction de la temperature de paroi et du debit en masse total d'ammoniac; il depend peu de la temperature d'entree du gaz et est pratiquement independant de la pression. Les coefficients d'amelioration apparents de la puissance echangee dans les conditions d'experience (rayonnement compris) ont atteint 1,8. Ce maximum observe se place vers une temperature moyenne de la paroi de 1250 deg. C. Ces coefficients decroissent quand le nombre de Reynolds de l'ecoulement croit. Finalement, une analyse theorique du phenomene est donnee ainsi que les perspectives d'applications. (auteurs)

  3. Quantitative measurements of small isotopic samples in gaseous mixtures by utilization of some nuclear properties; Etude des possibilites de mesures de faibles quantites de gaz radioactifs dans un melange en utilisant simultanement plusieurs proprietes nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Maragnon, J; Delperie, C

    1967-12-01

    The question is to define the characteristics of a group of measurements allowing the analysis of traces of radioactive rare gases in gas mixtures of different composition. To distinguish the radioactive isotopes from each other and the activity level reaching 10{sup 6} due to their nuclear properties, the method was chosen to use several nuclear properties: gamma radiation energy, beta particle energy, lifetime of excited states. The choice of a plastic scintillator as beta detector allows to answer satisfactorilly to this demand by measurement of nuclear constants because of the short de/excitation time of this detector. Another advantage is that it can be a reservoir for the sample without any destruction nor modification of the sample. The study has been based on the mixture of Kr-85, the analysis of other rare gases follwos immediately from the adopted principle. [French] Les auteurs ont oriente leur recherche vers une solution permettant de distinguer les isotopes radioactifs les uns des autres et dans des rapports d'activite pouvant atteindre 10{sup 6}, grace a plusieurs de leurs proprietes nucleaires, energie de rayonnement gamma, energie de la particule beta, temps de vie des niveaux excites. Le choix d'un scintillateur plastique comme detecteur beta permet de repondre d'une maniere satisfaisante a la mesure des constantes nucleaires en raison du temps de de/excitation rapide de ce scintillateur. Il offre en outre l'avantage de pouvoir servir de reservoir a l'echantillon sans entrainer aucune destruction ni modification de celui-ci. L'etude a ete basee sur la mixture de Kr-85, l'analyse des autre gaz rares decoulant immediatement du principe adopte. (auteur)

  4. Production of Methanol-Higher Alcohol Mixtures from Natural Gas via Syngas Chemistry Production de mélanges méthanol-alcools supérieurs à partir du gaz, via (CO + H2

    Directory of Open Access Journals (Sweden)

    Courty P.

    2006-11-01

    Full Text Available Despite the prevailing position of ethers (MTBE, TAME as octane boosters, and the low oil prices at present, alcohol synthesis remains one of the near future means of natural gas upgrading via syngas chemistry. After a review of the available process development data in the field, this paper focuses on the IFP process studies, based on the CuCo and CuNi catalysts developed by Institut Français du Pétrole (IFR, France and Idemitsu Kosan (Japan. The adequacy between the product specifications, and the optimization of the performances is then discussed in a technico-economic context, together with a presentation of lab scale, pilot scale and demonstration scale test results. As a conclusion, a prospective overall view brings together todays economics and some improvement guidelines dealing with investments, operating cost and catalyst performances. Cette publication présente les travaux de R & D (Recherche et Développement menés par l'Institut Français du Pétrole (IFP, France et Idemitsu Kosan (Japon en synthèse d'alcools. Elle situe les résultats dans le contexte technique et économique actuel. L'accroissement constant des ressources prouvées en gaz et, chronologiquement, les deux crises pétrolières, la suppression du plomb dans les essences, ont conduit le monde industriel à intensifier les recherches concernant la synthèse d'alcools. Très récemment, les effets bénéfiques de l'addition d'alcools sur les émissions de polluants ont été mis en évidence. Toutefois, l'additivation de carburants par les alcools est en voie de disparition au profit des éthers, alors que, indépendamment, les procédés de production d'ammoniac, de méthanol, d'acide acétique, également fondés sur le gaz, se sont seuls développés. La synthèse d'alcools a fait l'objet de nombreux travaux, résumés dans les tableaux 1 et 2. L'étude des différents aspects réactionnels amène à prendre en compte l'exothermicité importante des r

  5. From Periodic Properties to a Periodic Table Arrangement

    Science.gov (United States)

    Besalú, Emili

    2013-01-01

    A periodic table is constructed from the consideration of periodic properties and the application of the principal components analysis technique. This procedure is useful for objects classification and data reduction and has been used in the field of chemistry for many applications, such as lanthanides, molecules, or conformers classification.…

  6. Periodic instantons and scattering amplitudes

    International Nuclear Information System (INIS)

    Khlebnikov, S.Yu.; Rubakov, V.A.; Tinyakov, P.G.

    1991-04-01

    We discuss the role of periodic euclidean solutions with two turning points and zero winding number (periodic instantons) in instanton induced processes below the sphaleron energy E sph . We find that the periodic instantons describe certain multiparticle scattering events leading to the transitions between topologically distinct vacua. Both the semiclassical amplitudes and inital and final states of these transitions are determined by the periodic instantons. Furthermore, the corresponding probabilities are maximal among all states of given energy. We show that at E ≤ E sph , the periodic instantons can be approximated by infinite chains of ordinary instantons and anti-instantons, and they naturally emerge as deformations of the zero energy instanton. In the framework of 2d abelian Higgs model and 4d electroweak theory we show, however, that there is not obvious relation between periodic instantons and two-particle scattering amplitudes. (orig.)

  7. Holonomic systems for period mappings

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jingyue, E-mail: jychen@brandeis.edu [Department of Mathematics, Brandeis University, Waltham, MA 02454 (United States); Huang, An, E-mail: anhuang@math.harvard.edu [Department of Mathematics, Harvard University, Cambridge, MA 02138 (United States); Lian, Bong H., E-mail: lian@brandeis.edu [Department of Mathematics, Brandeis University, Waltham, MA 02454 (United States)

    2015-09-15

    Period mappings were introduced in the sixties [4] to study variation of complex structures of families of algebraic varieties. The theory of tautological systems was introduced recently [7,8] to understand period integrals of algebraic manifolds. In this paper, we give an explicit construction of a tautological system for each component of a period mapping. We also show that the D-module associated with the tautological system gives rise to many interesting vanishing conditions for period integrals at certain special points of the parameter space.

  8. Microprocessor controlled digital period meter

    International Nuclear Information System (INIS)

    Keefe, D.J.; McDowell, W.P.; Rusch, G.K.

    1980-01-01

    A microprocessor controlled digital period meter has been developed and tested operationally on a reactor at Argonne National Laboratory. The principle of operation is the mathematical relationship between asymptotic periods and pulse counting circuitry. This relationship is used to calculate and display the reactor periods over a range of /plus or minus/1 second to /plus or minus/999 seconds. The time interval required to update each measurement automatically varies from 8 seconds at the lowest counting rates to 2 seconds at higher counting rates. The paper will describe hardware and software design details and show the advantages of this type of Period Meter over the conventional circuits. 1 ref

  9. Inflammability of magnesium and its alloys in carbon dioxide either pure or mixed with water vapour, air or oxygen; Inflammabilite du magnesium et de ses alliages dans le gaz carbonique et ses melanges avec la vapeur d'eau, l'air ou l'oxygene

    Energy Technology Data Exchange (ETDEWEB)

    Baque, P; Chevilliard, C; Darras, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Whereas low contents of metallic additions have only a small influence on the temperature at which magnesium begins to burn in carbon dioxide, an increase in the specific surface area of the samples is likely to reduce it considerably, the self-heating phenomena being then more pronounced. On the other hand, the exact nature of the surrounding atmosphere is a very important factor; thus the temperature at which ignition begins increases with increasing carbon dioxide pressure, decreases very rapidly when the moisture content of this gas increases up to 3000 v.p.m., and decreases regularly when the partial pressure of air or oxygen increases. (authors) [French] Alors que de faibles teneurs en additions metalliques n'ont que peu d'influence sur la temperature d'inflammation du magnesium dans le gaz carbonique, l'augmentation de la surface specifique des echantillons est susceptible de l'abaisser fortement, le phenomene d'autochauffage se trouvant alors accru. D'autre part, la nature exacte de l'atmosphere gazeuse ambiante est un facteur tres important; ainsi la temperature d'inflammation croit avec la pression du gaz carbonique, decroit tres rapidement lorsque sa teneur en humidite augmente jusqu'a 3000 v.p.m., et diminue regulierement lorsque la pression partielle d'air ou d'oxygene augmente. (auteurs)

  10. Study of the formation and of the distribution of dissolved gases and hydrogen peroxide in water from a swimming-pool reactor (triton) (1961); Etude de la formation et de la repartition des gaz dissous et de l'eau oxygenee dans l'eau d'un reacteur piscine (triton) (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Chenouard, J; Rozenberg, J; Dolle, L; Dirian, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    In order to determine experimentally the amount of radiolysis in the swimming-pool reactor Triton, direct measurements have been made of the quantity of radiolysis gas and hydrogen peroxide in the water, at the entry and exit of the core. The concentration distribution of these gases in the reactor was also determined. An explanation is given as to why no gases evolution is seen in the swimming-pool reactors of the C.E.A. The overall amount of radiolysis is zero, and a simple interpretation of this result is possible. The real amount of radiolysis occurring in the reactor core can be calculated. This is in satisfactory agreement with certain measurement mad elsewhere. (authors) [French] Pour determiner experimentalement le taux de radiolyse dans la pile piscine Triton, des mesures directes de la quantite de gaz de radiolyse et d'eau oxygenee dans l'eau a l'entree et a la sortie du coeur ont ete faites. La repartition de la concentration de ces gaz dans la piscine a egalement ete determinee. On explique pourquoi aucun degagement gazeux n'est observe dans les piles piscines du CE.A. Le taux de radiolyse global est nul, et une interpretation simple de ce resultat est possible. Un taux de radiolyse reel dans le coeur du reacteur peut etre calcule. Celui-ci est en accord satisfaisant avec certaines determinations faites ailleurs. (auteurs)

  11. Forward Period Analysis Method of the Periodic Hamiltonian System.

    Directory of Open Access Journals (Sweden)

    Pengfei Wang

    Full Text Available Using the forward period analysis (FPA, we obtain the period of a Morse oscillator and mathematical pendulum system, with the accuracy of 100 significant digits. From these results, the long-term [0, 1060] (time unit solutions, ranging from the Planck time to the age of the universe, are computed reliably and quickly with a parallel multiple-precision Taylor series (PMT scheme. The application of FPA to periodic systems can greatly reduce the computation time of long-term reliable simulations. This scheme provides an efficient way to generate reference solutions, against which long-term simulations using other schemes can be tested.

  12. Detecting periodicities with Gaussian processes

    Directory of Open Access Journals (Sweden)

    Nicolas Durrande

    2016-04-01

    Full Text Available We consider the problem of detecting and quantifying the periodic component of a function given noise-corrupted observations of a limited number of input/output tuples. Our approach is based on Gaussian process regression, which provides a flexible non-parametric framework for modelling periodic data. We introduce a novel decomposition of the covariance function as the sum of periodic and aperiodic kernels. This decomposition allows for the creation of sub-models which capture the periodic nature of the signal and its complement. To quantify the periodicity of the signal, we derive a periodicity ratio which reflects the uncertainty in the fitted sub-models. Although the method can be applied to many kernels, we give a special emphasis to the Matérn family, from the expression of the reproducing kernel Hilbert space inner product to the implementation of the associated periodic kernels in a Gaussian process toolkit. The proposed method is illustrated by considering the detection of periodically expressed genes in the arabidopsis genome.

  13. Scheduling periodic tasks with slack

    NARCIS (Netherlands)

    Korst, J.H.M.; Aarts, E.H.L.; Lenstra, J.K.

    1997-01-01

    We consider the problem of nonpreemptively scheduling periodic tasks on a minimum number of identical processors, assuming that some slack is allowed in the time between successive executions of a periodic task. We prove that the problem is NP-hard in the strong sense. Necessary and sufficient

  14. A study of the fluorescence of the rare gases excited by nuclear particles. Use of the principle for the detection of nuclear radiation by scintillation; Etude de la fluorescence des gaz rares excites par des particules nucleaires. Utilisation pour la detection des rayonnements nucleaires par scintillation

    Energy Technology Data Exchange (ETDEWEB)

    Koch, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-12-15

    In the first part is studied the properties of atoms excited by the passage of {alpha} particles through the various rare gases at atmospheric pressure. A spectral analysis of the emitted light showed that certain impurities play an important part in producing the fluorescence, and it has led to the conclusion that the light emission contains at least two components - one very short - lived due to the direct deexcitation of the rare gas, the other relatively slower due to the energy transfers to the impurity. The measurement of the life-time of the excited states has confirmed this foregoing hypothesis, the rapid part of the impulse is extremely short: less than 2,25.10{sup -9} s in the case of xenon; the slower part has a life-time depending directly on the nitrogen concentration, nitrogen being the impurity giving the largest effect in all cases. The study of rare gases under the influence of an electric field has made it possible to show that the amount of light produced by an {alpha} particle can be multiplied (by 60, for example, in a field of 600 V:cm) so that the luminescent efficiency is greater than in the case of INaTI. In the second part the characteristics of the rare gases acting as scintillators is examined, the most important property being the absence of fluorescence saturation when the intensity of the excitation incident on the gas is very large. This, together with the very short time of scintillation has made it possible to study a certain number of nuclear physical applications (heavy particle energy-measurements, kinetic studies on nuclear reactors, neutron spectroscopy). (author) [French] On etudie dans la premiere partie les proprietes des atomes excites par le passage de particules {alpha} dans les differents gaz rares a la pression atmospherique. L'etude spectrale de la lumiere emise a montre que certaines impuretes jouent un role considerable dans la fluorescence et on a ete amene a penser que l'emission de lumiere comporte au moins deux

  15. A Comprehensive Numerical Study on Effects of Natural Gas Composition on the Operation of an HCCI Engine Une étude numérique complète sur les effets de la composition du gaz naturel carburant sur le réglage d’un moteur HCCI

    Directory of Open Access Journals (Sweden)

    Jahanian O.

    2011-11-01

    Full Text Available Homogeneous Charge Compression Ignition (HCCI engine is a promising idea to reduce fuel consumption and engine emissions. Natural Gas (NG, usually referred as clean fuel, is an appropriate choice for HCCI engines due to its suitable capability of making homogenous mixture with air. However, varying composition of Natural Gas strongly affects the auto-ignition characteristics of in-cylinder mixture and the performance of the HCCI engine. This paper has focused on the influence of Natural Gas composition on engine operation in HCCI mode. Six different compositions of Natural Gas (including pure methane have been considered to study the engine performance via a thermo-kinetic zero-dimensional model. The simulation code covers the detailed chemical kinetics of Natural Gas combustion, which includes Zeldovich extended mechanism to evaluate NOx emission. Validations have been made using experimental data from other works to ensure the accuracy needed for comparison study. The equivalence ratio and the compression ratio are held constant but the engine speed and mixture initial temperature are changed for comparison study. Results show that the peak value of pressure/temperature of in-cylinder mixture is dependent of fuel Wobbe number. Furthermore, engine gross indicated power is linearly related to fuel Wobbe number. Gross indicated work, gross mean effective pressure, and NOx are the other parameters utilized to compare the performance of engine using different fuel compositions. Le moteur HCCI (Homogeneous Charge Compression Ignition, ou à allumage par compression d’une charge homogène est une idée prometteuse pour réduire la consommation de carburant et les émissions polluantes. Le gaz naturel, considéré généralement comme un carburant propre, est un choix approprié pour les moteurs HCCI en raison de sa capacité à former avec l’air un mélange homogène. Cependant, la composition du gaz naturel influe fortement sur les caract

  16. Rationalization of Comet Halley's periods

    Science.gov (United States)

    Belton, Michael J. S.

    1990-01-01

    The sense of long axis orientation of Comet Halley during the Vega 1 encounter must be reversed from that deduced by Sagdeev et al. (1986) in order to harmonize the comet nucleus' Vega/Giotto-observed orientations with periodicities extracted from time-series brightness data. It is also demonstrated that Vega/Giotto observations can be satisfied by either a 2.2- or 3.7-day long-axis free precession period. A novel Fourier algorithm is used to reanalyze five independent data sets; strong evidence is adduced for periods harmonically related to a 7.4-day period. The preferred candidate models for Halley's nuclear rotation are characterized by a long-axis precession period of 3.7 days.

  17. Orbital periods of recurrent novae

    International Nuclear Information System (INIS)

    Schaefer, B.E.

    1990-01-01

    The class of recurrent novae (RN) with thermonuclear runaways contains only three systems (T Pyx, U Sco, and V394 CrA), for which no orbital periods are known. This paper presents a series of photometric observations where the orbital periods for all three systems are discovered. T Pyx is found to have sinusoidal modulation with an amplitude of 0.08 mag and a period of 2.3783 h (with a possible alias of 2.6403 h). U Sco is found to be an eclipsing system with an eclipse amplitude of roughly 1.5 mag and an orbital period of 1.2344 days. V394 CrA is found to have sinusoidal modulation with an amplitude of 0.5 mag and a period of 0.7577 days. Thus two out of three RN with thermonuclear runaways (or five out of six for all RN) have evolved companions. 16 refs

  18. Chaos to periodicity and periodicity to chaos by periodic perturbations in the Belousov-Zhabotinsky reaction

    International Nuclear Information System (INIS)

    Li Qianshu; Zhu Rui

    2004-01-01

    A three-variable model of the Belousov-Zhabotinsky reaction system subject to external sinusoidal perturbations is investigated by means of frequency spectrum analysis. In the period-1 window of the model, the transitions from periodicity to chaos are observed; in the chaotic window, the transitions from chaos to periodicity are found. The former might be understood by the circle map of two coupled oscillators, and the latter is partly explained by the resonance between the main frequency of the chaos and the frequency of the external periodic perturbations

  19. Iraqi architecture in mogul period

    Directory of Open Access Journals (Sweden)

    Hasan Shatha

    2018-01-01

    Full Text Available Iraqi architecture have many periods passed through it until now, each on from these periods have it is architectural style, also through time these styles interacted among us, to creating kind of space forming, space relationships, and architectural elements (detailed treatments, the research problem being from the multi interacted architectural styles causing some of confused of general characteristic to every style, that we could distinguish by it. Research tries to study architecture style through Mogul Conquest to Baghdad. Aim of research follow main characteristic for this architectural style in the Mogul periods on the level of form, elements, and treatments. Research depending on descriptive and analytical all buildings belong to this period, so from analyzing there style by, general form for building, architectural elements, and it architectural treatment, therefore; repeating this procedures to every building we get some similarities, from these similarities we can making conclusion about pure characteristic of the style of these period. Other side, we also discover some Dissimilar in the building periods, these will lead research to make what interacting among styles in this period, after all that we can drew clearly main characteristic of Architectural Style for Mogul Conquest in Baghdad

  20. The Periodic Table in Croatia

    Directory of Open Access Journals (Sweden)

    Raos, N.

    2011-12-01

    Full Text Available The Croatian (Yugoslav Academy of Sciences and Arts was the first academy to elect D. I. Mendeleev as its honorary member (1882, whereas the periodic table of the elements has been taught regularly at the Zagreb University since 1888. The early interest of Croatian chemists in the periodic table should be attributed primarily to their pan-Slavic attitude, particularly as proof that Slavic people were able to produce "their own Newtons" (M. V. Lomonosov and D. I. Mendeleev. Such enthusiastic views, however, did not help in analyzing the contribution of Mendeleev and other scientists to the discovery and development of the periodic table of the elements.

  1. Topological imprint for periodic orbits

    International Nuclear Information System (INIS)

    Martín, Jesús San; Moscoso, Ma José; Gómez, A González

    2012-01-01

    The more self-crossing points an orbit has the more complex it is. We introduce the topological imprint to characterize crossing points and focus on the period-doubling cascade. The period-doubling cascade topological imprint determines the topological imprint for orbits in chaotic bands. In addition, there is a closer link between this concept and the braids studied by Lettelier et al (2000 J. Phys. A: Math. Gen. 33 1809–25). (paper)

  2. Minimum period and the gap in periods of Cataclysmic binaries

    International Nuclear Information System (INIS)

    Paczynski, B.; Sienkiewicz, R.

    1983-01-01

    The 81 minute cutoff to the orbital periods of hydrogen-rich cataclysmic binaries is consistent with evolution of those systems being dominated by angular momentum losses due to gravitational radiation. Unfortunately, many uncertainties, mainly poorly known atmospheric opacities below 2000 K, make is physically impossible to verify the quadrupole formula for gravitational radiation by using the observed cutoff at 81 minutes. The upper boundary of the gap in orbital periods observed at about 3 hours is almost certainly due to enhanced angular momentum losses from cataclysmic binaries which have longer periods. The physical mechanism of those losses is not identified, but a possible importance of stellar winds is pointed out. The lower boundary of the gap may be explained with the oldest cataclysmic binaries, whose periods evolved past the minimum at 81 minutes and reached the value of 2 hours within about 12 x 10 9 years after the binary had formed. Those binaries should have secondary components of only 0.02 solar masses, and their periods could be used to estimate ages of the oldest cataclysmic stars, and presumably the age of Galaxy. An alternative explanation for the gap requires that binaries should be detached while crossing the gap. A possible mechanism for this phenomenon is discussed. It requires the secondary components to be about 0.2 solar masses in the binaries just below the gap

  3. Commuting periodic operators and the periodic Wigner function

    International Nuclear Information System (INIS)

    Zak, J

    2004-01-01

    Commuting periodic operators (CPO) depending on the coordinate x-hat and the momentum p-hat operators are defined. The CPO are functions of the two basic commuting operators exp(i x-hat 2π/a) and exp(i/h p-hat a), with a being an arbitrary constant. A periodic Wigner function (PWF) w(x, p) is defined and it is shown that it is applicable in a normal expectation value calculation to the CPO, as done in the original Wigner paper. Moreover, this PWF is non-negative everywhere, and it can therefore be interpreted as an actual probability distribution. The PWF w(x, p) is shown to be given as an expectation value of the periodic Dirac delta function in the phase plane. (letter to the editor)

  4. Nanopublication beyond the sciences: the PeriodO period gazetteer

    Directory of Open Access Journals (Sweden)

    Patrick Golden

    2016-02-01

    Full Text Available The information expressed in humanities datasets is inextricably tied to a wider discursive environment that is irreducible to complete formal representation. Humanities scholars must wrestle with this fact when they attempt to publish or consume structured data. The practice of “nanopublication,” which originated in the e-science domain, offers a way to maintain the connection between formal representations of humanities data and its discursive basis. In this paper we describe nanopublication, its potential applicability to the humanities, and our experience curating humanities nanopublications in the PeriodO period gazetteer.

  5. Gas Well Testing Analysis Using Finite-Difference Models and Optimization Techniques Analyse d'essais de puits de gaz par des modèles utilisant la méthode des différences finies et par des techniques d'optimisation

    Directory of Open Access Journals (Sweden)

    Darderes E. A.

    2006-11-01

    Full Text Available In reservoir engineering studies of gas fields, three important parameters are needed: the permeability-thickness product, the skin factor, and the inertial-turbulent factor. Several methods have been proposed to determine these parameters from gas well tests. The most powerful one is the pseudo-steady state analysis, where a linear dependence on a semilogarithmic plot is found between the real gas pseudo-pressure and time. Another one is the type-curve matching. Both have drawbacks because they can be rigorously applied only to specific cases. An automated type-curve match, which provides a general method to analyze well test data, is presented in this paper. It is based on the adjustment of a numerical model to gas well test data, by means of optimization techniques. The numerical model is the solution of the second order strongly non-linear partial differential equation which rules the radial flow of real gases towards a well. The differential equation is solved by finite-differences, taking into account the variation of gas properties with pressure. In order to simulate any gas well test, appropriate initial and boundary conditions are imposed. The least squares method is used to minimize residual differences between actual pressures measured during test and computed pressures. Two optimization techniques are applied to obtain the best estimate of parameters that minimize the sum of the square of the residuals: the univariate method of Fibonacci [1] and the multivariate method of Marquardt [1, 2]. This procedure is applied to a single-rate and a two-rate drawdown test. Numerical results showed excellent agreement with well test data. Les études de gisements de gaz rendent indispensables la connaissance de trois paramètres importants : la capacité de flux (produit de la perméabilité par l'épaisseur de la couche productrice, l'effet de peau et le facteur d'inertie et de turbulence. On connaît plusieurs méthodes pour déterminer ces

  6. Periodic testing in operative action

    International Nuclear Information System (INIS)

    Larm, T.

    2005-01-01

    Periodic testing forms a remarkable part of the regular work tasks of the shift crew. Testing is generally carried out beside the daily monitoring and control work. Even remarkable plant related differences may occur in the procedures and routines used in periodic testing. The goal is still always the same, to regularly ensure that the systems and equipment are in working order according to their design. This presentation studies with examples the execution and scope of periodic testing as well as the routines and procedures used in the testing in Loviisa power plant. The presentation is based on the testing procedures of Loviisa power plant and the aim is not to compare them to the procedures of other plants. The scope of periodic testing has increased and the routines and procedures have been developed as the operation experience has increased. The assessment of the need of periodic testing and the consideration of the practical execution possibilities should be a part of the plant's planning phase as a part of the planning process. (orig.)

  7. Inflation from periodic extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Higaki, Tetsutaro [Department of Physics, Keio University, Kanagawa 223-8522 (Japan); Tatsuta, Yoshiyuki, E-mail: thigaki@rk.phys.keio.ac.jp, E-mail: y_tatsuta@akane.waseda.jp [Department of Physics, Waseda University, Tokyo 169-8555 (Japan)

    2017-07-01

    We discuss a realization of a small field inflation based on string inspired supergravities. In theories accompanying extra dimensions, compactification of them with small radii is required for realistic situations. Since the extra dimension can have a periodicity, there will appear (quasi-)periodic functions under transformations of moduli of the extra dimensions in low energy scales. Such a periodic property can lead to a UV completion of so-called multi-natural inflation model where inflaton potential consists of a sum of multiple sinusoidal functions with a decay constant smaller than the Planck scale. As an illustration, we construct a SUSY breaking model, and then show that such an inflaton potential can be generated by a sum of world sheet instantons in intersecting brane models on extra dimensions containing orbifold. We show also predictions of cosmic observables by numerical analyzes.

  8. Periodicity, the Canon and Sport

    Directory of Open Access Journals (Sweden)

    Thomas F. Scanlon

    2015-10-01

    Full Text Available The topic according to this title is admittedly a broad one, embracing two very general concepts of time and of the cultural valuation of artistic products. Both phenomena are, in the present view, largely constructed by their contemporary cultures, and given authority to a great extent from the prestige of the past. The antiquity of tradition brings with it a certain cachet. Even though there may be peripheral debates in any given society which question the specifics of periodization or canonicity, individuals generally accept the consensus designation of a sequence of historical periods and they accept a list of highly valued artistic works as canonical or authoritative. We will first examine some of the processes of periodization and of canon-formation, after which we will discuss some specific examples of how these processes have worked in the sport of two ancient cultures, namely Greece and Mesoamerica.

  9. Periodicity and repeatability in data

    Science.gov (United States)

    Southwood, D.

    Using magnetic data from the first two years in Saturn orbit, the basic periodicity of apparent is examined with the aim of elucidating the `cam' shaft model of Espinosa et al. (2003) identifying the nature of the `cam' and giving a definitive period for its rotation. An initial hypothesis, supported by the spectral analysis of analysis of the first 8 months in orbit Gianpieri et al. (2006), is made that the source of the period is linked to something inside the planet and therefore that the source inertia means that the period effectively does not change over the 2 years. Moreover one expects that the source phase is fixed. Using this approach, not only can the period identified by spectral analysis (647.1 + 0.6 min.) be verified but also by phase analysis between successive passes over the 2 years the period can be refined to 647.6 + 0.1 min. The signal itself is remarkably reproducible from pass to pass. It appears in all three components of the field and its polarisation is unambiguously not attributable to direct detection of an internal field. Not only does the signal not decay rapidly with distance from the planet, but although it has the m=1 symmetry of a tilted dipole, the field lines diverge from the planet indicating an exterior source. This feature led to the `cam' model. The polarisation and comparisons of passes with different latitude profiles show a surprising north-south symmetry in the azimuthal field. The absence of asymmetry with respect to the magnetic equator rules out a direct magnetospheric-ionospheric interaction source. Accordingly, it is proposed that the basic `cam' effect is generated by a single hemisphere anomaly which creates hemisphere to hemisphere field aligned currents. The existence of Saturn phase related anomaly appears to produce a basic asymmetry in the inner magnetosphere that sets the phase of both an inflowing and outflowing sector in a rotating circulation system.

  10. Research into zirconium alloys resistant to carbon dioxide under pressure at temperatures of up to 600 deg C (1963); Recherche d'alliages de zirconium compatibles avec le gaz carbonique sous pression jusqu'a 500 ou 600 deg C (1063)

    Energy Technology Data Exchange (ETDEWEB)

    Baque, P; Dominget, R; Bossard, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    Zirconium is a metal having a relatively low neutron capture cross-section and a high melting point; it is thus possible to consider its use in particular as a canning material for fuel elements in CO{sub 2}-cooled nuclear reactors. A preliminary study of several types of zirconium showed that the metal is already strongly oxidised in this gas at 500 deg C. The 'breakaway' phenomenon is generalised; the oxidation rate is then linear and depends on the carbon dioxide pressure. An attempt was therefore made to find binary and tertiary alloys in order to improve the metal behaviour. Several interesting compositions were found: 1, 1.6 and 2.5 per cent of copper, 2 per cent of vanadium, and 0.05 and 0.5 per cent of calcium. Tertiary copper-molybdenum and copper-phosphorus alloys are also less liable to oxidation and in particular do not exhibit the 'breakaway' phenomenon even after a prolonged treatment at 600 deg C. (authors) [French] Le zirconium se trouve parmi les metaux a section de capture neutronique relativement faible et possede une temperature de fusion elevee; aussi peut on songer a l'employer notamment comme materiau de gainage d'elements combustibles pour reacteurs nucleaires refroidis au gaz carbonique. Une etude prealable de plusieurs qualites de zirconium a montre que le metal est deja assez fortement oxyde dans ce gaz des 500 deg C. En effet, le phenomene de ''breakaway'' est general; la vitesse d'oxydation devient alors lineaire et depend de la pression du gaz carbonique. La recherche d'alliages binaires et ternaires a donc ete entreprise afin de tenter d'ameliorer le comportement du metal. Elle a permis d'aboutir a quelques compositions interessantes: cuivre 1, 1,6 et 2,5 pour cent, vanadium 2 pour cent, et calcium 0,05 et 0,5 pour cent. Des alliages ternaires au cuivre-molybdene et cuivre-phosphore sont egalement moins oxydables, et en particulier ne presentent pas le phenomene de ''breakaway'', meme apres une longue exposition a 600 deg C. (auteurs)

  11. Theory of high frequency discharge in gases under low pressures. Experimental investigation of high-frequency type ion sources; Theorie de la decharge haute frequence dans les gaz aux faibles pressions. Etude experimentale des sources d'ions du type haute frequence

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, Jean

    1955-03-02

    The first part of this research thesis addresses the theory of high frequency discharge in gases under low pressures, and first proposes a calculation of the distribution function for electrons present within the gas. The author then studies the evolution of electron density within a discharge tube by assigning the governing role in electron multiplication to the secondary emission of tube walls. The second part proposes a detailed description of a source operating at 96.5 Mc/s, a discussion of measurements performed on this source, and the search for a theoretical explanation of some of its properties. The author then briefly analyses various existing types of high frequency sources, and finally discusses their use in corpuscular microscopy and in particle accelerators [French] La presente these comprend deux parties. La premiere est consacree a la theorie de la decharge haute frequence dans les gaz aux faibles pressions et comporte tout d'abord le calcul de la fonction de distribution des electrons presents au sein du gaz. Nous etudions ensuite l'evolution de la densite electronique a l'interieur d'un tube a decharge en attribuant, a l'emission secondaire des parois de ce dernier, le role essentiel dans la multiplicalion des electrons. Nous obtenons ainsi les conditions d'amorcage. Tout au long de cette etude, on doit distinguer soigneusement le cas ou le libre parcours moyen des electrons dans le gaz est inferieur aux dimensions de l'enceinte et le cas ou il leur est superieur. La deuxieme partie comprend la description detaillee d'une source fonctionnant sur 96.5 Mc/s, l'expose des mesures effectuees sur celle-ci et la recherche d'une explication theorique de certaines de ses proprietes. Nous faisons ensuite une breve analyse des divers types de sources d'ions haute frequence existant a l'heure actuelle et nous terminons en traitant de leur utilisation en microscopie corpusculaire et dans les accelerateurs de particules.

  12. An improved test for periodicity

    International Nuclear Information System (INIS)

    Davies, S.R.

    1990-01-01

    I discuss two widely used methods of testing for periodicity, phase dispersion minimization and epoch-folding. Using an analysis of variance approach, I demonstrate the close relationship between these two methods. I also show that the significance test sometimes used in phase dispersion minimization is statistically inaccurate, and that the test used in epoch-folding is an approximation valid only for large sample sizes. I propose a new test statistic, applicable to either epoch-folding or PDM, which is statistically sound for all sample sizes, and which is also more sensitive to periodicity than the test statistics previously used with these two methods. (author)

  13. Sigmoid Volvulus Complicating Postpartum Period

    Directory of Open Access Journals (Sweden)

    Kelsey E. Ward

    2017-01-01

    Full Text Available Background. Sigmoid volvulus is a rare complication of pregnancy and the puerperium. Case. A 19-year-old patient, gravida 1 para 0 at 41 0/7 weeks of gestation, admitted for late-term induction of labor underwent an uncomplicated primary low transverse cesarean delivery for arrest of descent. Her postoperative period was complicated by sudden onset of abdominal pain and the ultimate diagnosis of sigmoid volvulus. Conclusion. Prompt surgical evaluation of an acute abdomen in the postpartum period is essential; delayed diagnosis and treatment can lead to significant maternal morbidity and mortality.

  14. Hydrogen purification by periodic adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Barg, Christian; Secchi, Argimiro R.; Trierweiler, Jorge O. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. de Engenharia Quimica]. E-mail: cbarg@enq.ufrgs.br; arge@enq.ufrgs.br; jorge@enq.ufrgs.br

    2000-07-01

    The periodic adsorption processes have been widely used for industrial applications, mainly because it spends less energy than the usual gas separation processes, like the cryogenic distillation. The largest commercial application of periodic adsorption processes is the pressure swing adsorption (PSA) applied to hydrogen purification. Although its wide use in the chemical and petrochemical industry, there are no reports in the open literature about complete modeling studies of a complex commercial unit, with multiple adsorbents and multiple beds and several feed components. This study has as objective the modeling, optimization and dynamical analysis of an industrial PSA unit for hydrogen purification. (author)

  15. Availability of periodically tested systems

    International Nuclear Information System (INIS)

    Signoret, J.P.

    1979-01-01

    There is at the present time a need in accurate models to asess the availability of periodically tested stand-by systems. This paper shows how to improve the well known 'saw-tooth curve' model in order to take into account various reliability parameters. A model is developed to assess the pointwise and the mean availabilities of periodically tested stand-by systems. Exact and approxination formulae are given. In addition, the model developed herein leads to optimize the test interval in order to minimize the mean unavailability. A safety diesel in a nuclear power plant is given as an example

  16. Greenhouse effect: a point about the sequestration of carbonic gas; Effet de serre: le dossier de la sequestration du gaz carbonique

    Energy Technology Data Exchange (ETDEWEB)

    Chesnais, L.

    2005-10-01

    'Factor 4' is the name of a working group whose aim is to propose different ways to cut the emission of greenhouse gases in France by a factor 4. One of solutions is to store in deep geological layers a great part of the carbonic gas produced on earth. The storing capacities of aquifers are 10 folds as important as the capacities of gas and oil natural reservoirs currently in service throughout the world. Feasibility tests have been made in Norway, Canada and Algeria. A lot of uncertainties concerning the behaviour of CO{sub 2} in geological layers over very large time periods (from 500.000 to 1 million years) have to be cleared before considering an industrial scale use. As a consequence no industrial use is planned before 10 to 15 years from now. Furthermore the industrial use requires a cost below 20 euros the tonne which is far from the estimation of the cost based on the today's technology (50 to 70 euros the tonne of carbonic gas collected). (A.C.)

  17. Poultry farming buildings. Natural gas heating. Guidebook of installation rules; Batiments d`elevage avicole. Chauffage au gaz. Guide des regles d`installation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The technical and economical performances of a poultry farm are greatly influenced by the mastery of ambient temperature during the first days of husbandry. The natural gas space heating installation must answer these requirements and also respect all safety rules concerning the personnel and the animals. In order to answer the questions of poultry farming professionals, the technical association of the natural gas industry (ATG) in France and the Groupama insurance company have redefined the new version of this brochure which integrates the recent technological advances and defines the minimum quality and safety rules required to achieve a natural gas heating installation. The different topics presented are: the gas supply (aerial fixed reservoirs), the general distribution panel (location, command systems, regulation systems for LPG installations, electrical equipments), the distribution pipes (general supply, indoor pipes, flexible pipes, pipe fittings), the heating systems (power, choice, power supply, fastening, air renewal), the check and sign and the start-up of the installation, the periodical control and maintenance operations. (J.S.)

  18. [ A registry of ischaemic cardiopathies among active workers at Electricité de France-Gaz de France. Program development and first results].

    Science.gov (United States)

    Chevalier, A; Zins, M; Godard, C; Morin, J; Jourdain, V; François, F; Lambrozo, J; Goldberg, M; Ducimetière, P

    2001-02-01

    The social security department of the French national electric and gas company has established an ischemic heart disease register among a population of about 140 000 employees based on sick leaves as well as deaths recorded with their medical cause. History of the illness, medical tests and treatments were known retrospectively from the consulting physicians of the company. Acute coronary events recorded were: inaugural angina pectoris, myocardial infarction, sudden coronary death and fortuitous discovery of coronary disease. A first study conducted on employees during the 1993-1995 period showed infarction incidence age rates similar to those estimated from the French MONICA registers for France as a whole. Regional discrepancies were observed for myocardial infarction rates: Nord-Pas de Calais, Champagne-Ardennes, Lorraine, Franche-Comté and Limousin were at the most elevated risk (SIR=131, 155, 169, 125 and 178 resp). Large variations according to socio-economic status were observed. This register will permit studies on the links between socio-economic status at different professional career points and the occurrence of ischemic heart disease and the evaluation of the impact of psychosocial factors such as previous depressive disorders.

  19. Preliminary report on inventory of greenhouse gases. Phase 1; Rapport preliminaire sur l`inventaire de gaz a effet de serre. Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Fenhann, J

    1997-07-01

    The United Nations Framework Convention on Climate Change (UNFCC) requires the signatory countries to develop, periodically update, publish and make available to the Conference of the Parties national inventories of anthropogenic greenhouse gas emissions (GHG) by sources and removals by sinks, using comparable methodologies as well as to formulate policies and programmes to adapt to or mitigate climate change. Following the entree-into-force of the Convention, the Government of Burkina Faso requested the Danish Government to provide technical assistance and support in order to assess national contributions to global GHG accumulation and to identify the most relevant GHG mitigation and adaptation options for national target-setting and action. This report presents the results of the Phase 1 of the project. The report summarises: (i) the national inventory on GHG emissions and sinks; (ii) a preliminary forecast of GHG emissions and possible mitigation options, and (iii) a first attempt to analyse the vulnerability and possible adaptation strategies to climate change. (LN) 51 refs.

  20. Periodic and quasiperiodic revivals in periodically driven interacting quantum systems

    Science.gov (United States)

    Luitz, David J.; Lazarides, Achilleas; Bar Lev, Yevgeny

    2018-01-01

    Recently it has been shown that interparticle interactions generically destroy dynamical localization in periodically driven systems, resulting in diffusive transport and heating. In this Rapid Communication we rigorously construct a family of interacting driven systems which are dynamically localized and effectively decoupled from the external driving potential. We show that these systems exhibit tunable periodic or quasiperiodic revivals of the many-body wave function and thus of all physical observables. By numerically examining spinless fermions on a one-dimensional lattice we show that the analytically obtained revivals of such systems remain stable for finite systems with open boundary conditions while having a finite lifetime in the presence of static spatial disorder. We find this lifetime to be inversely proportional to the disorder strength.

  1. Cosmophysical periods in European history

    International Nuclear Information System (INIS)

    Vladimirskij, B.M.; Kislovskij, L.D.

    1995-01-01

    In social systems there are rhythms synchronised by cosmical periods. These rhythms have partly biological origin. Some natural cycles also might influence upon historical processes (as such as climatic and epidemical). The analysis of the literature shows that there is rhythmic component in European history where solar activity cycles -11 and 340 years are presented. 17 refs., 2 tabs

  2. Genius of the periodic table

    International Nuclear Information System (INIS)

    1969-01-01

    'Isn't it the work of a genius!' exclaimed Academician V.I. Spitsyn, USSR, a member of the Scientific Advisory Committee when talking to an Agency audience in January. His listeners shared his enthusiasm. Academician Spitsyn was referring to the first formulation a hundred years ago by Professor Dmitry I. Mendeleyev of the Periodic Law of Elements. (author)

  3. Glass Waveguides for Periodic Poling

    DEFF Research Database (Denmark)

    Fage-Pedersen, Jacob; Jacobsen, Rune Shim; Kristensen, Martin

    2005-01-01

    Planar silica-based waveguide devices have been developed for second-harmonic generation by poling with periodic electrodes. We show that detrimental charge transport can occur along interfaces, but with proper choice of fabrication, high-quality devices are obtained....

  4. Periodic linear differential stochastic processes

    NARCIS (Netherlands)

    Kwakernaak, H.

    1975-01-01

    Periodic linear differential processes are defined and their properties are analyzed. Equivalent representations are discussed, and the solutions of related optimal estimation problems are given. An extension is presented of Kailath and Geesey’s [1] results concerning the innovations representation

  5. Model selection in periodic autoregressions

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)

    1994-01-01

    textabstractThis paper focuses on the issue of period autoagressive time series models (PAR) selection in practice. One aspect of model selection is the choice for the appropriate PAR order. This can be of interest for the valuation of economic models. Further, the appropriate PAR order is important

  6. Periodic progress report, 6 months

    DEFF Research Database (Denmark)

    Juhl, Thomas Winther; Nielsen, Jakob Skov

    This is the first progress report of the BriteEuram project named "High Power Laser Cutting for Heavy Industry" ("Powercut"). The report contains a summary of the objectives of the first period, an overview of the technical progress, a comparison between the planed and the accomplished work...

  7. Un nouveau moyen de mesure absolue du taux gazeux des mélanges gaz-liquides : le SMAC A New Absolute Measurement of the Volumetric Gas Ratio of Gas-Liquid Mixture: the Smac

    Directory of Open Access Journals (Sweden)

    Porot P.

    2006-11-01

    Full Text Available Du graphe (P, V de la compression d'un mélange gaz-liquide, on peut tirer la valeur du taux volumique de gaz dans le mélange. La vérification théorique et expérimentale de ce principe ainsi que ses limites d'application comme moyen de mesure sont présentées. Ce résultat a été utilisé pour développer un système de mesure de l'aération de l'huile moteur, le SMAC (Système de Mesure d'Aération par Compressibilité. Des exemples d'application, tels que l'étude de la sensibilité de certaines huiles à l'aération, sont exposés. Oil aeration can be a real problem in engine oil circuit. The involved lubrication power decrease and thermic properties changes can damage the engine. Furthermore, the increased compressibility is very dangerous for hydraulic systems like valve lash adjusters. A first step to control this aeration is to be able to measure it. Gammametry is often used but this measurement needs a very precise calibration and is quite complicated and dangerous. A new absolute measurement has been discovered, based on the difference of compressibility between air and oil. It is absolute because the measurement principle is independant of the conditions, The system does not need a new calibration at each new environment. It is valid for any gas-liquid mixture. From the (P, V graph of a gas-liquid mixture compression, one can derive the gas-liquid volumetric ratio. The log-log graph (P/PO, 1-V/VO of a mixture sample pressurization always shows an inflexion point. The y value of this inflexion point (1-V/VO is equal to the volumetric gas ratio of the sample (before compression. This phenomenon is obvious on hydraulic curves (see Annexe 1. To check it, we have proceeded to a theoretical demonstration and an experimental verification. The theoretical demonstration of this principle concludes that the principle is verified as long as the ration P index 0 / alpha B is small. B is the oil bulk modulus, alpha is the volumetric gas ratio

  8. Some economic aspects of natural uranium graphite gas reactor types. Present status and trends of costs in France; Quelques aspects economiques de la filiere uranium naturel - Graphite - gaz. Etat actuel et tendance des couts en France

    Energy Technology Data Exchange (ETDEWEB)

    Gaussens, J; Tanguy, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Leo, B [Electricite de France (EDF), 75 - Paris (France)

    1964-07-01

    reduction in investment costs can be obtained without relying on fuel enrichment, and that this development is accompanied moreover by improvements in the operational safety of the reactor. The economic aspects of the main technical problems entailed by these developments are discussed: loading and unloading machines, blowers etc... (authors) [French] Dans une premiere partie, on situe l'interet economique de l'utilisation de l'uranium naturel comme combustible. Cet interet reside a la fois dans le nombre limite et la simplicite relative des operations de mise en forme des elements combustibles, dans le faible cout du produit fini par kwh et dans les immobilisations modestes en capital qu'implique ce cycle par rapport ou cycle de l'uranium enrichi. Tous ces elements permettent de reduire le caractere aleatoire des evaluations des couts, particulierement marque dans le cas de l'uranium enrichi, en raison de la complexite de son cycle et des incertitudes concernant le prix du plutonium. Enfin, la diversite des sources d'approvisionnement en concentre d'uranium naturel opposee au quasi monopole actuel de la separation isotopique, et le faible cout du stockage de ce concentre, offrent des garanties en matiere de securite d'approvisionnement et d'independance economique et politique appreciables par rapport a l'uranium enrichi. En ce qui concerne l'ensemble des capitaux immobilises, on montre que si le cout des centrales au graphite-gaz est plus eleve que celui des centrales eau legere pour certaines gammes de puissance, ce resultat est fortement nuance des que l'on fait intervenir dans un souci d'independance nationale le cout de l'equipement de production des combustibles de l'une et l'autre filiere. Enfin, le cout marginal de la puissance du reacteur au graphite est faible, ses limitations technologiques ont considerablement recule (grace en particulier a l'utilisation du beton precontraint). On sait que la tendance actuelle est a l'accroissement de la puissance unitaire des

  9. Autoinflammatory Diseases with Periodic Fevers.

    Science.gov (United States)

    Sag, Erdal; Bilginer, Yelda; Ozen, Seza

    2017-07-01

    One purpose of this review was to raise awareness for the new autoinflammatory syndromes. These diseases are increasingly recognized and are in the differential diagnosis of many disease states. We also aimed to review the latest recommendations for the diagnosis, management, and treatment of these patients. Familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), tumor necrosis factor receptor-associated periodic fever syndrome (TRAPS), and hyperimmunoglobulinemia D and periodic fever syndrome/mevalonate kinase deficiency (HIDS/MVKD) are the more common autoinflammatory diseases that are characterized by periodic fevers and attacks of inflammation. Recently much collaborative work has been done to understand the characteristics of these patients and to develop recommendations to guide the physicians in the care of these patients. These recent recommendations will be summarized for all four diseases. FMF is the most common periodic fever disease. We need to further understand the pathogenesis and the role of single mutations in the disease. Recently, the management and treatment of the disease have been nicely reviewed. CAPS is another interesting disease associated with severe complications. Anti-interleukin-1 (anti-IL-1) treatment provides cure for these patients. TRAPS is characterized by the longest delay in diagnosis; thus, both pediatricians and internists should be aware of the characteristic features and the follow-up of these patients. HIDS/MVKD is another autoinflammatory diseases characterized with fever attacks. The spectrum of disease manifestation is rather large in this disease, and we need further research on biomarkers for the optimal management of these patients.

  10. Vertebrate fauna of the Roman period, migrations period and Medieval period in Vojvodina (Serbia

    Directory of Open Access Journals (Sweden)

    Radmanović Darko P.

    2014-01-01

    Full Text Available Based on current published and unpublished research results, a total of 16 vertebrate species members of mammal (Mammalia, bird (Aves and osteichthyes (Osteichthyes classes have been registered at 11 archaeological sites from the Roman Period in Vojvodina. Mammals dominate with 12 species and one genus, birds are present with 3 species, and osteichthyes with one. From the Migration Period, at 9 sites, 22 vertebrate species have been registered, of which 13 species and one genus of mammals, 4 species and one genus of birds, and 5 species from the Osteichthyes class. At 8 sites from the Medieval Period, 16 vertebrate species have been registered. Mammals are the most numerous class with 10 species and one genus, while birds are present with 4 species and one genus. Furthermore, two species of osteichthyes have also been registered.

  11. Low intensity natural gas infrared in sports centres; L'infrarouge a basse intensite au gaz naturel dans les centres sportifs

    Energy Technology Data Exchange (ETDEWEB)

    Lajoie, S. [Gaz Metropolitain, Montreal, PQ (Canada)

    2002-09-30

    Infrared devices are being employed more and more for heating buildings. They were traditionally used to heat large spaces higher than 3 metres, such as aviation hangars and industrial buildings. Natural gas infrared devices have found other applications, namely in sports centres, due in large part to the energy efficiency and the resulting comfort. There are three types of infrared devices: low intensity or low intensity tubes, high intensity, and catalytic infrared. Each type of device possesses specific characteristics and applications. For example, infrared tubes are used to uniformly heat a specific area. High intensity devices possess a more intense heat and concentrated in a confined space. Catalytic devices do not have flames, and they can be used in industrial drying processes and thermoforming. In the case of skating rinks, the use of low intensity natural gas infrared tubes is ideal. They reduce the crossed effects of ice cooling load and the spectators need for heat. This is due to infrared acting more on mass (spectators and bleachers) than ambient air. The author described the situation at the Val d'Or arena, Quebec where an energy saving project was initiated two years ago, involving the installation for one of the ice surfaces, of movement sensors to turn off infrared tubes when the rink is unoccupied. The payback period for such equipment is short. The case of the Soccerplex at Lachine, part of the larger City of Montreal, was also discussed. This sports centre comprises indoor soccer fields with 30 foot-high ceilings and large area covering 66,000 square feet (3 soccer fields). Once again, low intensity natural gas infrared tubes were installed and have proved successful.

  12. Study of total ionization by {alpha} particles, in pure gases and gaseous mixtures containing metastable atoms, as a function of temperature; Etude de l'ionisation totale par les paricules {alpha}, dans les gaz purs et les melanges gazeux contenant des atomes metastables, en fonction de la temperature

    Energy Technology Data Exchange (ETDEWEB)

    Bristeau, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    Experiments have been carried out on the total ionization by alpha particles, in pure gases and gaseous mixtures containing metastable atoms, as a function of temperature. Using a different experimental method, the results for the mean ionization energy at 300 K given by Jesse in 1953 have been confirmed to within 1 per cent. It is established that in pure gases the mean energy W required to form a pair of ions remains constant as the temperature varies from 77 to 300 K. It is shown that there is a temperature effect for W in binary gas mixtures of the type A-B containing meta-stable atoms A{sup *} and an 'impurity' B. A systematic study is made of the change {delta}W in W as a function of the temperature and of the B 'impurity' concentration in the mixtures Ne - Ar, Ne - Kr, Ne - H{sub 2}, Ne - N{sub 2}, Ne - CH{sub 4} and He - Ar. Experiments have been carried out on a ternary gas mixture of the type A - B - C, where C is a second ionizable 'impurity' added to the binary mixture A - B; they show the existence of excited atoms B{sup *} formed from the 'impurity' B. Finally, it is shown that the amount of metastable atoms formed in a pure gas must be very close to the number N{sub 0} of ion pairs, and that there must exist a correlation between the number N{sub 0} of ion pairs and the number {approx_equal} N{sub 0} of metastable atoms created in the pure rare gases. (author) [French] On realise des experiences sur l'ionisation totale par les particules alpha, dans les gaz purs et les melanges gazeux contenant des atomes metastables, en fonction de la temperature. Avec une methode experimentale differente, on retrouve a mieux que 1 pour cent pres les valeurs de l'energie moyenne d'ionisation que JESSE a obtenues en 1953 et a 300 K. On etablit que dans les gaz purs, l'energie moyenne W pour creer une paire d'ions demeure constante, quand la temperature varie entre 77 et 300 K. On met en evidence un effet de temperature sur W, dans les melanges gazeux binaires du type

  13. Law no. 2004-803 from August 9, 2004 relative to electricity and gas public utilities and to the power and gas companies; Loi no. 2004-803 du 9 aout 2004 relative au service public de l'electricite et du gaz et aux entreprises electriques et gazieres

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-09-01

    The aim of this law is to allow the administrations to avoid to use their eligibility right with the opening of the electricity and gas markets to competition. It changes the juridical status of the two public utilities Electricite de France (EdF) and Gaz de France (GdF) into two anonymous companies and creates two additional companies for the management of the power and gas networks. It ensures also the transposition of the European directives from June 26, 2003 (2003/54/CE and 2003/55/CE). It contains some proper dispositions and modifies various existing French laws, in particular the law no. 46-628 from April 8, 1946 about the electricity and gas nationalization and the law no. 2000-108 from February 10, 2000 relative to the modernization and development of the electric public utility. (J.S.)

  14. Evolutionary dynamics of incubation periods.

    Science.gov (United States)

    Ottino-Loffler, Bertrand; Scott, Jacob G; Strogatz, Steven H

    2017-12-21

    The incubation period for typhoid, polio, measles, leukemia and many other diseases follows a right-skewed, approximately lognormal distribution. Although this pattern was discovered more than sixty years ago, it remains an open question to explain its ubiquity. Here, we propose an explanation based on evolutionary dynamics on graphs. For simple models of a mutant or pathogen invading a network-structured population of healthy cells, we show that skewed distributions of incubation periods emerge for a wide range of assumptions about invader fitness, competition dynamics, and network structure. The skewness stems from stochastic mechanisms associated with two classic problems in probability theory: the coupon collector and the random walk. Unlike previous explanations that rely crucially on heterogeneity, our results hold even for homogeneous populations. Thus, we predict that two equally healthy individuals subjected to equal doses of equally pathogenic agents may, by chance alone, show remarkably different time courses of disease.

  15. Period of an Interrupted Pendulum

    Science.gov (United States)

    Miller, Bradley E.

    2002-11-01

    While demonstrating a classic conservation-of-energy problem to my AP Physics students, I became curious about the periodic motion that ensued for certain initial conditions. The original problem consists of releasing a mass at the end of a string from an initial position horizontal to the plane of a table. The string comes in contact with a peg some distance below the point where the string is attached at the top. One is asked to find what minimum fraction of the string's length should the peg be placed to have the mass complete a circle about the peg. However, when the mass is released from much lower heights, the system undergoes periodic motion that can be thought of as an interrupted pendulum.

  16. Periodicity of the stable isotopes

    CERN Document Server

    Boeyens, J C A

    2003-01-01

    It is demonstrated that all stable (non-radioactive) isotopes are formally interrelated as the products of systematically adding alpha particles to four elementary units. The region of stability against radioactive decay is shown to obey a general trend based on number theory and contains the periodic law of the elements as a special case. This general law restricts the number of what may be considered as natural elements to 100 and is based on a proton:neutron ratio that matches the golden ratio, characteristic of biological and crystal growth structures. Different forms of the periodic table inferred at other proton:neutron ratios indicate that the electronic configuration of atoms is variable and may be a function of environmental pressure. Cosmic consequences of this postulate are examined. (author)

  17. On nonlinear periodic drift waves

    International Nuclear Information System (INIS)

    Kauschke, U.; Schlueter, H.

    1990-09-01

    Nonlinear periodic drift waves are investigated on the basis of a simple perturbation scheme for both the amplitude and inverse frequency. The coefficients for the generation of the forced harmonics are derived, a nonlinear dispersion relation is suggested and a criterion for the onset of the modulational instability is obtained. The results are compared with the ones obtained with the help of a standard KBM-treatment. Moreover cnoidal drift waves are suggested and compared to an experimental observation. (orig.)

  18. Long Period Seismological Research Program

    Science.gov (United States)

    1974-10-31

    in central Asia as observed at the high-gain long- period sites. Preliminary results from observations at Chiang Mai (CHG) show that the complexity...Preliminary results from observations at Chiang Mai (CHG) show that the complexity of the surface wave signals from many events in the Tadzhik-Kirgiz...and receivers. A number of Interesting features can be illustrated by examining portions of three selsmograms recorded at Chiang Mai (CHO

  19. Theory and Practice of a New Class of Equipment for Separation of Particulates from Gases: the Turbulent Flow Precipitator Le précipitateur turbulent : un nouveau type de dispositif de séparation de particules présentes dans un courant de gaz. Théorie et technologie

    Directory of Open Access Journals (Sweden)

    Dullien F. A. L.

    2006-12-01

    Full Text Available The main classes of separators of particulates from gases comprise inertial separators, filters, (wet scrubbers and electrostatic precipitators, each of which technique has its proper niche and each has its advantages and its disadvantages. In the present paper a new class of equipment, the turbulent flow precipitator (TFP for gas cleaning is described that, though at the present only in its infancy, is rapidly gaining popularity because it has some advantages over each and every known type of separator and it has very few limitations. TFPs are far more efficient for the removal of fine particles than inertial separators, unlike filters they do not plug up, they do not present secondary disposal problems and they require less maintenance (and are less expensive than electrostatic precipitators. They can be very efficient also in the submicron range of particle size and there are no practical limitations as far as high temperatures and/or corrosive atmospheres are concerned. They are equally suitable for the removal of solid and liquid particles from gases. Turbulent flow precipitators work on the principle of turbulent eddy penetration into deep regions where there is no net flow, where the eddies die out and where the fine particulates carried by the eddies deposit on collector surfaces. TFPs comprise two well defined regions:- straight, uniform and unobstructed flow passages in which the gas carrying the suspended fine particulates is passed in turbulent flow;- and adjacent collection regions where there is no net gas flow and where all of the separation of particles from the gas takes place. Hence, a TFP is a filter in which the separation of the particulates from the gas takes place outside the passages where the gas flows. Les principaux séparateurs de particules dans un courant de gaz existants sur le marché sont les séparateurs par inertie, les filtres, les laveurs et les électrofiltres. Chaque type de séparateur est destiné à une

  20. Karabük İlindeki Hava Kirliliğinin Doğal Gaz Kullanımı İle Değişimi / The Change of Air Pollution in Karabuk with the Usage of Natural Gas

    Directory of Open Access Journals (Sweden)

    Yusuf CAY

    2012-12-01

    Full Text Available Fosil kaynaklı yakıtların kullanımı, hava kirliliğine sebebiyet veren en önemli unsurlardan bir tanesidir. Bu yakıtların bilinçsizce kullanılması sonucunda çevre problemlerine özellikle de hava kirliliğine neden olmaktadır. Yapılan bu çalışmada, Karabük ilinin doğalgaz kullanmaya başlamadan önceki ve doğalgaza geçiş ile hava kirlilik parametreleri (SO2 ve PM10 incelenmiştir. Doğal gaz kullanımının hava kalitesine etkisi araştırılmıştır. İlde ısınma ihtiyacını karşılamak için kömür, fuel-oil ve mazot kullanılırken 2010 yılı itibariyle doğal gaza geçilmiştir. Doğal gazın kullanılmaya başlanmasıyla bu yakıtların kullanımı azalmıştır. Çalışmanın sonunda, Hava Kalitesi Değerlendirme ve Yönetimi Yönetmeliğinde (HKDYY belirtilen, SO2 için 250 μg/m3 değerinin doğal gaz kullanımına geçilmeden önce bazı aylarda üzerinde olduğu görülmüş ve doğal gaz kullanılmaya başlanmasından sonraki dönemlerde ise 250 μg/m3 değerinin aşılmadığı görülmüştür. PM10 için yönetmelikte belirtilen 200 μg/m3 değerinin kış sezonunda aşıldığı tespit edilmiştir. 2010 yılında Doğal gaz kullanımına geçiş ile birlikte bu değerde tekrar bir düşüş gözlenmiştir. Doğal gaz kullanım oranı artıkça havadaki SO2 ve PM10 değerlerinde ciddi düşüşler olduğu gözlenmiştir. The Change of Air Pollution in Karabuk with the Usage of Natural Gas The Usage of fossil origin fuels is one of the most important cause of air pollution. The usage of these fuels unconsciously causes environmental problems especially air pollution. In this study air pollution parameters (SO2 ve PM10 were analyzed before and after the usage of natural gas in Karabuk. The effect of usage natural gas on air quality is researched. In this city before 2010 coal, foul-oil and diesel were used to provide heat demanded then it is started using natural gas by 2010.With starting the usage of

  1. Etude d'un procédé d'hydroliquéfaction du charbon pour la production simultanée de gaz et de carburant . . . . . Studies of a Coal Hydrogenation Process to Produce CO-Currently Gas and Gasoline

    Directory of Open Access Journals (Sweden)

    Franckowiak S.

    2006-11-01

    Full Text Available Un des principaux moyens de réintroduire le charbon dans le marché énergétique français est de le transformer en produits utiles comme le gaz de réseau ou les carburants. Les procédés d'oxyvapogazéification permettent d'obtenir un gaz de synthèse qui peut être ensuite converti en gaz riche ou en produits liquides. L'hydrogénation en phase liquide (ou hydroliquéfaction se présente pour le long terme comme une seconde voie qui offre des avantages spécifiques - taux de conversion du charbon et rendement élevés, - production directe de gaz de substitution (GNS et de carburant, - possibilité d'utilisation d'hydrogène provenant de l'électricité nucléaire. Un programme d'étude a été lancé avec la participation du Gaz de France (GDF, du Centre d'études et de recherches des Charbonnages de France (Cerchar, de l'institut Français du Pétrole (lFP et du Centre National de la Recherche Scientifique (CNRS dans le cadre du Groupe d'Étude de la Conversion du Charbon par Hydrogénation (GECH. Un banc d'essai d'hydroliquéfaction situé au Cerchar, d'un débit de 10 kg/h de mélange charbon-solvant, permet d'obtenir des hydrogénats dans des conditions variées et en présence de divers catalyseurs. L'étude de la valorisation de ces hydrogénats est effectuée dans les laboratoires de l'lFP. Les essais et les études effectués permettent d'envisager la production à volonté du GNS, de carburants ou des deux ensemble. Un modèle d'optimisation a été réalisé au GDF pour étudier et comparer les différentes filières en prenant en compte l'utilisation d'hydrogène d'électrolyse ou d'hydrogène produit sur place à partir du résidu de liquéfaction. One of the main ways to bring coal in the future french energy market is to transform it into valuable products. The oxygen steam gasification processes give a synthesis gas which can be converted into SNG or gasoline in a catalytic stage. The liquid phase hydrogenation process is a

  2. Long-Period Solar Variability

    Energy Technology Data Exchange (ETDEWEB)

    GAUTHIER,JOHN H.

    2000-07-20

    Terrestrial climate records and historical observations of the Sun suggest that the Sun undergoes aperiodic oscillations in radiative output and size over time periods of centuries and millenia. Such behavior can be explained by the solar convective zone acting as a nonlinear oscillator, forced at the sunspot-cycle frequency by variations in heliomagnetic field strength. A forced variant of the Lorenz equations can generate a time series with the same characteristics as the solar and climate records. The timescales and magnitudes of oscillations that could be caused by this mechanism are consistent with what is known about the Sun and terrestrial climate.

  3. Pairs of dual periodic frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Goh, Say Song

    2012-01-01

    The time–frequency analysis of a signal is often performed via a series expansion arising from well-localized building blocks. Typically, the building blocks are based on frames having either Gabor or wavelet structure. In order to calculate the coefficients in the series expansion, a dual frame...... is needed. The purpose of the present paper is to provide constructions of dual pairs of frames in the setting of the Hilbert space of periodic functions L2(0,2π). The frames constructed are given explicitly as trigonometric polynomials, which allows for an efficient calculation of the coefficients...

  4. Periodic dynamics in queuing networks

    Energy Technology Data Exchange (ETDEWEB)

    Addabbo, Tommaso [Information Engineering Department, University of Siena, Via Roma 56, 53100 Siena (Italy)], E-mail: addabbo@dii.unisi.it; Kocarev, Ljupco [Macedonian Academy of Sciences and Arts, bul. Krste Misirkov 2, P.O. Box 428, 1000 Skopje, Republic of Macedonia (Macedonia, The Former Yugoslav Republic of)], E-mail: lkocarev@ucsd.edu

    2009-08-30

    This paper deals with state-dependent open Markovian (or exponential) queuing networks, for which arrival and service rates, as well as routing probabilities, may depend on the queue lengths. For a network of this kind, following Mandelbaum and Pats, we provide a formal definition of its associated fluid model, and we focus on the relationships which may occur between the network stochastic dynamics and the deterministic dynamics of its corresponding fluid model, particularly focusing on queuing networks whose fluid models have global periodic attractors.

  5. Periodic permanent magnet focused klystron

    Science.gov (United States)

    Ferguson, Patrick; Read, Michael; Ives, R Lawrence

    2015-04-21

    A periodic permanent magnet (PPM) klystron has beam transport structures and RF cavity structures, each of which has permanent magnets placed substantially equidistant from a beam tunnel formed about the central axis, and which are also outside the extent of a cooling chamber. The RF cavity sections also have permanent magnets which are placed substantially equidistant from the beam tunnel, but which include an RF cavity coupling to the beam tunnel for enhancement of RF carried by an electron beam in the beam tunnel.

  6. Forgiveness in the intertestamental period

    Directory of Open Access Journals (Sweden)

    Sang-Mong Lee

    2012-02-01

    Full Text Available The article suggests answers to the following questions: what are the characteristics of God�s forgiveness in the intertestamental literature and what connection do these characteristics have with the Old Testament? Important passages in the late Second Temple period that expose the characteristics of God�s forgiveness, such as certain Qumran texts (1QH 12:35�37, 1QH 13:2 and the Damascus Document 14:18�19, the writings of Philo and Josephus, the Apocrypha and the Pseudepigrapha, are investigated for this purpose.

  7. Apport de la géostatistique à la description des stockages de gaz en aquifère Contribution of Geostatistics to Describing Aquifer Gas-Storage Reservoirs

    Directory of Open Access Journals (Sweden)

    Delhomme J. P.

    2006-11-01

    Full Text Available L'étude du comportement d'un réservoir de gaz en nappe aquifère réclame une connaissance aussi précise que possible des caractéristiques géométriques et pétrophysiques des couches réservoirs. Les moyens d'investigation sont de deux natures : - forages permettant une connaissance locale des roches réservoirs ; - mesures sismiques conduisant à une estimation approximative des cotes de certains repères stratigraphiques, en des points situés le long de profils. Les données recueillies sont donc, par nature, fragmentaires et discrètes : là où elles sont absentes, il y a lieu d'estimer les grandeurs étudiées en tenant compte au mieux de notre connaissance de leur variabilité spatiale. Ce problème d'interpolation optimale a donné lieu, depuis une vingtaine d'années, à l'élaboration et la mise en pratique d'un outil théorique particulièrement bien adapté aux besoins exprimés par les techniciens des sciences de la terre : la théorie des variables régionalisées due à G. Matheron. Des programmes informatiques mettant en oeuvre cette théorie sont actuellement opérationnels. Des exemples d'application en sont donnés : - tracé automatique de cartes structurales à partir des données de forages et des mesures sismiques ; - estimation des incertitudes de prévision sur les profondeurs ; - tracé de plusieurs variantes de carte compatibles avec les données ; - établissement d'éléments statistiques relatifs à une grandeur caractéristique d'un stockage : volume stockable par exemple ; - génération automatique des données nécessaires à la mise en oeuvre d'un modèle maillé de réservoir. Predicting and monitoring the behavior of an aquifer gas-storage reservoir requires as precise a knowledge as possible of the geometric and petrophysical properties of the reservoir layer. Two ways of obtaining this information can be given: (a Boreholes which provide local knowledge of the reservoir, and (b Seismic measurements

  8. Optimisation énergétique des procédés de séparation en raffinage et en traitement de gaz naturel Optimal Use of Energy in Separation Processes for Refining and Natural Gas Treatment

    Directory of Open Access Journals (Sweden)

    Rojey A.

    2006-11-01

    Full Text Available Cet article présente une méthode d'optimisation des procédés de séparation basée sur une analyse thermodynamique. Cette analyse s'appuie sur un bilan exergétique qui est établi dans le cas général d'un système quelconque opérant en régime permanent. Les facteurs qui conditionnent le rendement exergétique d'un procédé de séparation sont ensuite examinés. Il en résulte une méthode d'optimisation basée sur une réduction des irréversibilités thermodynamiques. Des exemples concrets d'application en raffinage et en traitement de gaz naturel sont présentés, et on montre comment cette analyse peut déboucher sur la conception de procédés innovants. The optimization of separation units in refining and natural-gas processing must take into consideration new needs and constraints that may seem incompatible. New installations must be designed not only on the basis of energy optimization but also by seeking to minimize investments and to respect new rules concerning environmental protection. The optimization described in this article is based on a thermodynamic analysis of different material and energy exchanges, The energybalance provides a suitable basis for making this analysis. It leads to the defining of an exergy efficiency that is all the higher as the thermodynamic irreversibilities are reduced, and that tends toward one for an ideal reversible system. For a separation process, a separation exergyterm is defined that correspond to the minimum separation work . Distillation is the basic separation operation. The exergy efficiency of this operation is low, and we show that, even in a relatively favorable cas, it is no greater than a value of about 6%. For an atmospheric distillation operation of crude oil, the exergy efficiency is about 4%. This overall exergy efficiency is the product of an external exergy efficiency and an internal exergy efficiency. The external exergy efficiency can be improved by better thermal

  9. Single Pellet String Reactor for Intensification of Catalyst Testing in Gas/Liquid/Solid Configuration Réacteur catalytique de type “filaire” pour l’intensification de tests catalytiques en configuration gaz/liquide/solide

    Directory of Open Access Journals (Sweden)

    Hipolito A.I.

    2010-09-01

    . Ce probleme est particulierement critique pour les reactions rapides et tres exothermiques. Une nouvelle geometrie de reacteur est proposee pour intensifier les transferts de matieres autour des grains de catalyseur et accelerer les vitesses superficielles des fluides : le “reacteur filaire”. Pour caracteriser cette nouvelle geometrie de reacteur, une etude hydrodynamique a ete menee avec un reacteur filaire horizontal de section carree de 4,0 × 4,0 mm2 rempli de particules spheriques de diametre compris entre 2 et 4 mm et simulant des grains de catalyseur. Les regimes d’ecoulement ontete etudies a partir d’analyses d’images, des mesures de perte de pression et de distribution de temps de sejour qui ont ete effectuees en ecoulement monophasique liquide et diphasique gaz/liquide. Deux principaux regimes d’ecoulements ont ete observes: un regime de “bulles isolees” et un regime de type “stratifie”. Les retentions liquides sont toujours superieures a 60 %, ce qui indique en complement d’observations visuelles que le catalyseur est toujours correctement irrigue par l’ecoulement liquide. En ecoulement diphasique gaz/liquide, l’ecoulement est de type piston puisque les nombres de Peclet sont toujours superieurs a 40. La perte de pression est principalement controlee par les forces de frottement liquide/solide et les valeurs de perte de pression restent tres faibles en conditions de tests catalytiques (< 0,1 bar. Les caracteristiques hydrodynamiques indiquent donc que ce reacteur est approprie pour des tests catalytiques. Enfin, ce type de reacteur a ete mis en oeuvre en conditions de reactions catalytiques pour effectuer des tests d’un catalyseur commercial pour une reaction d’hydrogenation de l’allene. Le reacteur a permis d’effectuer des tests en conditions isothermes avec une tres faible quantite de catalyseur (inferieure a 2 cc et d’acceder aux performances catalytiques pour des temps de contact tres courts impossible a atteindre

  10. Revue des aspects hydrodynamiques des réacteurs catalytiques gaz-liquide-solide à lit fixe arrosé Hydrodynamics of Gas-Liquid-Solid Trickle-Bed Reactors: a Critical Review

    Directory of Open Access Journals (Sweden)

    Attou A.

    2006-12-01

    Full Text Available Bien que les aspects hydrodynamiques soient d'une importance primordiale lors de la conception et du fonctionnement d'un réacteur gaz-liquide-solide à lit fixe arrosé, les méthodes de calcul prédictif proposées sont restées fort rudimentaires. La plupart des études portant sur ce sujet ont été menées dans des conditions quasi atmosphériques alors que les réacteurs industriels fonctionnent à des pressions élevées. C'est seulement récemment que quelques résultats expérimentaux ont été obtenus à des hautes pressions, et des corrélations ont été proposées dans ces conditions pour prédire la transition entre les régimes ruisselant et pulsé, la perte de pression et le taux de rétention de liquide. L'objectif de cet article est double. D'une part, une synthèse y est présentée ; elle fait état des connaissances acquises sur les divers aspects hydrodynamiques du réacteur triphasique à lit fixe, incluant les récents développements réalisés à hautes pressions. D'autre part, les modèles et les corrélations actuels de transitions de régimes, de la perte de pression et du taux de rétention de liquide sont soumis à une analyse critique en confrontant leurs prédictions à l'ensemble des données expérimentales obtenues pour un large intervalle de la pression de fonctionnement du réacteur. Des conclusions objectives ont pu être tirées concernant les aptitudes des corrélations et des modèles actuels à être utilisées pour les calculs de conception des réacteurs triphasiques à lit fixe industriels. Malheureusement, il apparaît qu'aucun modèle de transitions entre les régimes ruisselant et pulsé n'est satisfaisant. Seule la corrélation empirique de Larachi et al. (1993 s'avère être jusqu'à présent la méthode la plus précise pour prédire la position de la frontière entre les régimes ruisselant et pulsé dans un large domaine de la pression de fonctionnement. Par ailleurs, aucune corr

  11. Periodic weather and climate variations

    International Nuclear Information System (INIS)

    Ivanov, Vladimir V

    2002-01-01

    Variations in meteorological parameters are largely due to periodic processes and can be forecast for several years. Many such processes are related to astronomical factors such as the gravitational influences of the Moon and the Sun, and the modulation of solar irradiance by lunar and planetary motion. The Moon, Jupiter, and Venus have the strongest effect. These influences produce lines in the spectra of meteorological variations, which are combinations of the harmonics of the frequencies of revolution of the planets, the Earth, and the Moon around the Sun with the harmonics of the lunar revolution around the Earth. Due to frequency differences between the orbital and radial motions, fine spectral features of three types appear: line splitting, line-profile complications due to radial oscillations, and additional lines due to the combination of radial-oscillation frequencies with perturbation harmonics. (reviews of topical problems)

  12. The periodic table in Flatland

    International Nuclear Information System (INIS)

    Kibler, M.

    1995-01-01

    The D-dimensional Coulomb system serves as a starting point for generating generalized atomic shells. These shells are ordered according to a generalized Madelung rule in D dimensions. This rule together with an Aufbau Prinzip is applied to produce a D-dimensional periodic table. A model is developed to rationalize the ordering of the shells predicted by the generalized Madelung rule. This model is based on the introduction of an Hamiltonian, invariant under the q-deformed algebra U q (so(D)), that breaks down the SO (D + 1) dynamical symmetry of the hydrogen atom in D dimensions. The D = 2 case (Flatland) is investigated with some details. It is shown that the neutral atoms and the (moderately) positive ions correspond to the values q = 0.8 and q = 1, respectively, of the deformation parameter q. (authors). 55 refs

  13. Periodic folding of viscous sheets

    Science.gov (United States)

    Ribe, Neil M.

    2003-09-01

    The periodic folding of a sheet of viscous fluid falling upon a rigid surface is a common fluid mechanical instability that occurs in contexts ranging from food processing to geophysics. Asymptotic thin-layer equations for the combined stretching-bending deformation of a two-dimensional sheet are solved numerically to determine the folding frequency as a function of the sheet’s initial thickness, the pouring speed, the height of fall, and the fluid properties. As the buoyancy increases, the system bifurcates from “forced” folding driven kinematically by fluid extrusion to “free” folding in which viscous resistance to bending is balanced by buoyancy. The systematics of the numerically predicted folding frequency are in good agreement with laboratory experiments.

  14. A periodic table for cancer.

    Science.gov (United States)

    Epstein, Richard J

    2015-01-01

    Cancers exhibit differences in metastatic behavior and drug sensitivity that correlate with certain tumor-specific variables such as differentiation grade, growth rate/extent and molecular regulatory aberrations. In practice, patient management is based on the past results of clinical trials adjusted for these biomarkers. Here, it is proposed that treatment strategies could be fine-tuned upfront simply by quantifying tumorigenic spatial (cell growth) and temporal (genetic stability) control losses, as predicted by genetic defects of cell-cycle-regulatory gatekeeper and genome-stabilizing caretaker tumor suppressor genes, respectively. These differential quantifications of tumor dysfunction may in turn be used to create a tumor-specific 'periodic table' that guides rational formulation of survival-enhancing anticancer treatment strategies.

  15. Liquefied natural gas; Gaz naturel liquefie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Total has interests in five of the world's largest liquefaction plants, which together account for roughly 40% of global LNG production capacity. This presentation illustrates the activities of the Group in the LNG sector. It discusses the advantages of the LNG as a clean energy, the LNG market, the liquefaction process and plants, the LNG trading marketing and shipping, the re-gasification and TOTAL promoting innovation. (A.L.B.)

  16. GAZ - slishkom vremennaja alternativa / Roman Vikulov

    Index Scriptorium Estoniae

    Vikulov, Roman

    2005-01-01

    Narva linna küttekomisjoni poolt organiseeritud seminarist, kus osales ka Põhjamaade juhtivasse energeetikakompaniisse kuuluva kontserni Fortum Termest arengudirektor Kaido-Paul Bõstrov ja Vene Föderatsiooni majandusministeeriumi riiklik ekspert, akadeemik Vladimir Borovkov

  17. Gaz nam ne ukaz / Josef Kats

    Index Scriptorium Estoniae

    Kats, Josef, 1977-

    2007-01-01

    Valitsuse eitavast otsusest Vene-Saksa gaasijuhtme uuringute taotlusele, välisminister Urmas Paeti kommentaaridest pressikonverentsil. Välisminister leiab, et antud olukorras oli valitsuse otsus ainuõige

  18. Dynamical diffraction in periodic multilayers

    CERN Document Server

    Sears, V F

    1997-01-01

    Exact reflectivity curves are calculated numerically for various periodic multilayers using the optical matrix method in order to test the dynamical theory of diffraction. The theory is generally valid for values of the bilayer thickness d up to about 100 A. For somewhat larger values of d, where the theory begins to break down, the initial discrepancy is in the phase of the oscillations in the wings of the peaks. For very large values of d, where the first-order Bragg peak approaches the edge of the mirror reflection, two general types of multilayers can be distinguished. In the first (typified in the present work by Ni/Ti), there is a large (30% or more) reduction in the actual value of the critical wave vector for total reflection while, in the second (typified here by Fe/Ge), there is very little reduction (3 % or so). The origin of these two very different types of behavior is explained. It is also shown that, within the dynamical theory of diffraction, the change in the position of the center of the Dar...

  19. The Hydrodynamic Characteristics of Cocurrent Downflow and Cocurrent Upflow Gas-Liquid-Solid Catalytic Fixed Bed Reactors: the Effect of Pressure Les caractéristiques hydrodynamiques des réacteurs gaz-liquide-solide à lit de catalyseur fixe à écoulement cocourant montant et descendant : l'influence de la pression

    Directory of Open Access Journals (Sweden)

    Wild G.

    2006-11-01

    Full Text Available While most catalytic fixed bed gas-liquid reactors of the petrol industry work at quite high pressures, the academic scientific work in this field concerned itself almost exclusively with the domain of approximatively atmospheric pressures. The authors present the results of some years of experimental investigations on the hydrodynamic characteristics of trickle bed reactors and lately of cocurrent upflow reactors. During the last years, results were also obtained under pressures up to 8 MPa. The measurements were made in a small scale cold flow equipment (diameter 23 mm. Different aqueous and organic more or less viscous, eventually coalescence inhibiting liquids, four gases and a number of non porous more or less wettable particles were used. The liquid holdup was determined in all cases by measuring liquid phase residence time distribution by different tracers. The following conclusions may be drawn:(a In the high interaction regime, it is the inertia of the gas and the liquid phases which is the main cause of the dissipation of mechanical energy. In this regime, results obtained in cocurrent upflow and downflow are approximately equal. (b Most correlations of literature are unable to predict the effect of pressure on the pressure drop or the liquid holdup. (c The gas viscosity has no influence on the hydrodynamics. It is therefore possible to simulate for example hydrogen under high pressure conditions by another gas of the same density (at a much lower pressures. A critical evaluation of the correlations and/or models of literature is presented, concerning their ability to represent the different characteristics as a function of pressure. Tandis que la plupart des réacteurs industriels gaz-liquide à lit de catalyseur fixe fonctionnent à assez hautes pressions, les travaux scientifiques académiques sont, dans ce domaine, presque exclusivement consacrés aux pressions avoisinant la pression atmosphérique. Les auteurs présentent les r

  20. Crystallography beyond periodic Crystal perfection

    International Nuclear Information System (INIS)

    Estevez-Rams, E.

    2008-01-01

    Full text: The discovery of the quasi-crystals [D. Schechtman et. Al., Phys.] Rev. Lett. [53, 1951-1953 (1984)] made very narrow definition of the crystalline state based on the periodicity of a local arrangement of atoms. Since the definition of this State has been a matter of much controversy [G.R. Desiraju, Nature 423, 485 (2003); S. van Smaalen, IUCR Aperiodic Commission Reports. August 7, 2002; International Union of Crystallography. Report of the Executive Committee for 1991; ACTA Cryst. A48, 922-946 (1992)]. We will make a presentation of the current time of the crystallography in this regard from the conceptual point of view. We show the use of the formalism of algorithmic complexity or Kolmogorov [M. Li and P. Vitanyi, An Introduction to Kolmogorov Complexity and Its Applications (Springer Verlag, Heidelberg, 1993), W.H. Zurek, Phys.] Rev. 40, 4731 (1989); Nature 341, 119-124 (1989)] provides a different perspective on the nature of the Crystallographic order. Infinite crystals can be considered solid with zero algorithmic complexities by atom. Show statistical analysis of inorganic compounds [J.L.C. Daams et al., Atlas of Crystal Structure Types for Intermetallic Phases (ASM International, Ohio, 1991), Fachinformationszentrum/NIST Inorganic Crystal Structure Database, Karlsruhe (2003) icsd.fkf.mpg.de] demonstrating that the minimization of complexity is a trend in the crystalline arrangement. We will then compare the degree of disorder of some typical solids according to their algorithmic complexity. Finally, space diffraction will be studied from this same perspective and will be discussed that zero algorithmic complexities by point in space of diffraction does not necessarily imply the same thing for the Atomic arrangement. The discrete portion of the diffraction pattern is a fingerprint of the underlying order but not the actual existence of long-range order. Experimental results will be showcased [E. Estévez-Rams et al., Physical Review B, 63 (2001

  1. Periodic precursors of nonlinear dynamical transitions

    International Nuclear Information System (INIS)

    Jiang Yu; Dong Shihai; Lozada-Cassou, M.

    2004-01-01

    We study the resonant response of a nonlinear system to external periodic perturbations. We show by numerical simulation that the periodic resonance curve may anticipate the dynamical instability of the unperturbed nonlinear periodic system, at parameter values far away from the bifurcation points. In the presence of noise, the buried intrinsic periodic dynamics can be picked out by analyzing the system's response to periodic modulation of appropriate intensity

  2. Visualisation of Gasoline and Exhaust Gases Distribution in a 4-Valve Si Engine; Effects of Stratification on Combustion and Pollutants Visualisation de la répartition du carburant et des gaz brûlés dans un moteur à 4 soupapes à allumage commandé ; effet de la stratification sur la combustion et les polluants

    Directory of Open Access Journals (Sweden)

    Deschamps B.

    2006-12-01

    Full Text Available sAn indirect method to map the burned gases in SI engine has been developed. It is based on visualisation by Laser Induced Fluorescence of the unburned mixture seeded with biacetyl. Both internally and externally recirculated burned gases are monitored. This diagnostic is complementary to the LIF technique applied to measure the gasoline distribution. These LIF gasoline and burned gases measurements are applied in a 4-valve optical access SI engine for a large range of operating conditions. These include variations of both fuel injection and burned gas recirculation modes causing different types of stratification leading to very distinct heat release and exhaust emissions characteristics. Tumble level and spark location are also modified. The observation of the actual stratification in the engine forms a sound basis explanation of the engine performance. Parameters allowing an optimisation of NOx and HC levels can be inferred, and in particular the effectiveness of recirculation and fuel injection strategies. The conclusions are confirmed by measurements in a single engine cylinder conventional head with the same geometry. Une méthode indirecte pour cartographier les gaz brûlés dans un moteur à allumage commandé a été développée. Elle est fondée sur une visualisation à partir de la fluorescence induite par laser (LIF du mélange air-carburant non brûlé et ensemencé avec du biacétyl. Les gaz brûlés provenant à la fois des recirculations internes et externes sont observés. Ce type de diagnostic est complémentaire des techniques de LIF utilisées pour observer la distribution du carburant. Ces mesures de concentration sont réalisées dans un moteur à 4 soupapes avec accès optiques, pour une gamme étendue de conditions opératoires. Celles-ci comprennent des variations des modes d'injection du carburant et des modes de recirculation des gaz brûlés, provoquant ainsi différents types de stratifications qui correspondent

  3. Geochemical Study of Natural CO2 Emissions in the French Massif Central: How to Predict Origin, Processes and Evolution of CO2 Leakage Étude géochimique des émissions naturelles de CO2 du Massif Central : origine et processus de migration du gaz

    Directory of Open Access Journals (Sweden)

    Battani A.

    2010-05-01

    de surveillance des futurs sites de stockage de CO2. Au cours des campagnes de terrain, nous avons analysé des flux de CO2 entre le sol et l’atmosphère, et nous avons prélevé et analysé à la fois des gaz des sols, et du gaz provenant de sources carbo-gazeuses, présentes dans toute la région. Un dispositif de « monitoring continu » dans le temps a également été testé, afin d’enregistrer conjointement les teneurs en CO2 de l’atmosphère et dans le sol en un point précis. Nous avons pu mettre au point un suivi géochimique basé sur la composition isotopique des gaz rares prélevés dans les sols. L’ensemble de nos résultats, confronté à la géologie de terrain, nous a permis de mettre en évidence l’origine mantellique du CO2. Ce CO2 remonte rapidement à la surface à l’état gazeux, le long de failles normales et/ou décrochantes, actives actuellement. Les teneurs et flux de CO2 dans le sol sont spatialement variables et élevés, et montrent également une origine mantellique. Les teneurs atmosphériques semblent faiblement augmenter par rapport à l’important dégazage observé dans la région.

  4. Mesure et modélisation multidimensionnelle des transferts thermiques gaz-paroi dans le cas des moteurs à allumage commandé Measurement and Multidimensional Modeling of Gas-Wall Heat Transfers in Spark-Ignition Engines

    Directory of Open Access Journals (Sweden)

    Gilaber P.

    2006-11-01

    Full Text Available A cette fin, deux étapes de recherche ont été mises en oeuvre : une phase expérimentale et une phase calcul. Dans la phase expérimentale, des mesures ont été faites sur un moteur monocylindre équipé de flux-mètres à réponse rapide. Chaque flux-mètre est composé d'un cylindre d'acier, contenant deux thermocouples. Dans le but de montrer l'influence de l'aérodynamique sur les échanges thermiques, un anémomètre à Laser a été utilisé à l'aide d'une entretoise placée entre culasse et cylindre. L'entretoise comportait deux hublots et deux flux-mètres permettant la mesure simultanée des flux thermiques et des paramètres aérodynamiques à l'extérieur de la couche limite. Deux flux-mètres supplémentaires ont été placés dans la culasse et le système d'acquisition permettait d'enregistrer simultanément dix voies de mesure à chaque degré vilebrequin, parmi lesquelles deux composantes de vitesse et la pression cylindre. Une étude paramétrique a révélé les tendances suivantes : - les pertes globales aux parois au cours d'un cycle thermodynamique diminuent lorsque le régime augmente, mais la valeur maximale des flux locaux augmente en raison de l'élévation du niveau de turbulence; - le remplissage a peu d'effet sur l'aérodynamique; son influence sur les transferts thermiques est due principalement à l'augmentation de la densité des gaz, qui se traduit par une augmentation des flux. Dans la phase calcul, deux idées de base ont guidé notre travail : - pour des raisons de temps de calcul prohibitif, il est impossible de mailler la couche limite; les échanges thermiques ont donc été estimés à l'aide d'une loi de paroi; - on fait l'hypothèse que les champs locaux de densité, vitesse et turbulence conditionnent fortement les flux thermiques; ce seront les paramètres de la loi de paroi. Dans cet esprit, le modèle de transferts thermiques de DIWAKAR a été introduit dans le code multi-dimensionnel KIVA. Une

  5. Periodic Poisson Solver for Particle Tracking

    International Nuclear Information System (INIS)

    Dohlus, M.; Henning, C.

    2015-05-01

    A method is described to solve the Poisson problem for a three dimensional source distribution that is periodic into one direction. Perpendicular to the direction of periodicity a free space (or open) boundary is realized. In beam physics, this approach allows to calculate the space charge field of a continualized charged particle distribution with periodic pattern. The method is based on a particle mesh approach with equidistant grid and fast convolution with a Green's function. The periodic approach uses only one period of the source distribution, but a periodic extension of the Green's function. The approach is numerically efficient and allows the investigation of periodic- and pseudo-periodic structures with period lengths that are small compared to the source dimensions, for instance of laser modulated beams or of the evolution of micro bunch structures. Applications for laser modulated beams are given.

  6. Proposition d'explication de la formation d'hydrogène sulfuré dans les stockages souterrains de gaz naturel par réduction des sulfures minéraux de la roche magasin Proposed Explanation of Hydrogen-Sulfide Formation in Underground Natural-Gas Storage Structures by Reduction of Mineral Sulfides in the Reservoir Rock.

    Directory of Open Access Journals (Sweden)

    Bourgeois J. P.

    2006-11-01

    Full Text Available La formation d'hydrogène sulfuré dans les structures de stockage peu expliquer autrement que par l'action de bactéries sulfato-réductrices. La contenue dans la roche magasin constitue une source de sulfures capable d'alimenter en H2S le gaz naturel. La réduction de la pyrite en sulfures du type Fe 1-x S et l'équilibre de dissolution précipitation, lié principalement à la pression de CO2, dans les structures stockages, constituent un processus de formation d'H2S capable d'expliquer tativement et quantitativement les phénomènes observés sur le terrain. Un modèle simplifié de stockage reprend ce schéma et teste la sensibililté de la teneur en H2S à la valeur des paramètres physiques et chimiques définissant le stockage. Cette étude permet de proposer un certain nombre d'actions susceptibles de limiter la formation d'H2S et d'orienter les choix futurs du couple gaz naturel - structures de stockage. The formation of hydrogen sulfide in storage structures can be explained otherwise thon by the action of sulfate-reducing bacteria. The pyrite contained in the reservoir rock makes up a source of sulfides capable of supplying the natural gas with H2S.Reduction of pyrite ta sulfides of the Fe,-,S type and the dissolution precipitation equilibrium, linked mainly ta C02 pressure in storage structures, make up an H2S for-mation process capable of qualitatively and quantitatively explained phenomena observed in the field.A simplified storage model reflects this scheme and can be used ta test the sensi-tivity of the H2S content ta the value of the physical and chemical parameters defining the storage structure.This investigation can be used to propose various means of action (sable ta "mit H2S formation and ta guide future choices of natural gas/storage-structure pairs.

  7. Unstable periodic orbits and chaotic economic growth

    International Nuclear Information System (INIS)

    Ishiyama, K.; Saiki, Y.

    2005-01-01

    We numerically find many unstable periodic solutions embedded in a chaotic attractor in a macroeconomic growth cycle model of two countries with different fiscal policies, and we focus on a special type of the unstable periodic solutions. It is confirmed that chaotic behavior represented by the model is qualitatively and quantitatively related to the unstable periodic solutions. We point out that the structure of a chaotic solution is dissolved into a class of finite unstable periodic solutions picked out among a large number of periodic solutions. In this context it is essential for the unstable periodic solutions to be embedded in the chaotic attractor

  8. Depression in pregnancy and postpartum period.

    Science.gov (United States)

    Sood, Mamta; Sood, A K

    2003-01-01

    This prospective study was carried out in a service hospital, with the aim to study the prevalence and incidence of depression in pregnancy and postpartum period. Eighty Four consecutive patients attending the antenatal outpatient in the Obstetrics & Gynaecology department in their last trimester of pregnancy were recruited for the study. They were assessed on Beck Depression Inventory thrice viz. during third trimester of pregnancy, within 3 days of delivery (early postpartum period) & within 4-8 weeks of delivery (late postpartum period).The prevalence of depression was 8.3%, 20% and 12.8% respectively at three ratings. The incidence was 16% and 10% in the early & late postpartum period respectively. Further analysis revealed that depression in pregnancy correlated significantly with depression in early postpartum period, but not with late postpartum period. Depression in early postpartum period correlated with depression in late postpartum period.These findings have implications for early detection and care of women at risk for developing depression.

  9. Periodic solutions of nonlinear vibrating beams

    Directory of Open Access Journals (Sweden)

    J. Berkovits

    2003-01-01

    Full Text Available The aim of this paper is to prove new existence and multiplicity results for periodic semilinear beam equation with a nonlinear time-independent perturbation in case the period is not prescribed. Since the spectrum of the linear part varies with the period, the solvability of the equation depends crucially on the period which can be chosen as a free parameter. Since the period of the external forcing is generally unknown a priori, we consider the following natural problem. For a given time-independent nonlinearity, find periods T for which the equation is solvable for any T-periodic forcing. We will also deal with the existence of multiple solutions when the nonlinearity interacts with the spectrum of the linear part. We show that under certain conditions multiple solutions do exist for any small forcing term with suitable period T. The results are obtained via generalized Leray-Schauder degree and reductions to invariant subspaces.

  10. 21 CFR 573.240 - Calcium periodate.

    Science.gov (United States)

    2010-04-01

    ... with calcium hydroxide or calcium oxide to form a substance consisting of not less than 60 percent by... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium periodate. 573.240 Section 573.240 Food... Additive Listing § 573.240 Calcium periodate. The food additive calcium periodate may be safely used in...

  11. 39 CFR 121.2 - Periodicals.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Periodicals. 121.2 Section 121.2 Postal Service UNITED STATES POSTAL SERVICE POST OFFICE SERVICES [DOMESTIC MAIL] SERVICE STANDARDS FOR MARKET-DOMINANT MAIL PRODUCTS § 121.2 Periodicals. (a) End-to-End. (1) For all SCF turnaround Periodicals properly...

  12. 27 CFR 70.244 - Payroll period.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Payroll period. 70.244... Excise and Special (Occupational) Tax Limitations § 70.244 Payroll period. For purpose of determining the... established calendar period regularly used by the employer or other person levied upon for payroll or payment...

  13. 40 CFR 35.9035 - Budget period.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Budget period. 35.9035 Section 35.9035... ASSISTANCE Financial Assistance for the National Estuary Program § 35.9035 Budget period. An applicant may choose its budget period in consultation with and subject to the approval of the Regional Administrator. ...

  14. 10 CFR 603.1295 - Periodic audit.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Periodic audit. 603.1295 Section 603.1295 Energy... Used in this Part § 603.1295 Periodic audit. An audit of a participant, performed at an agreed-upon... an audit may cover. A periodic audit of a participant differs from an award-specific audit of an...

  15. 32 CFR 37.1325 - Periodic audit.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Periodic audit. 37.1325 Section 37.1325 National... TECHNOLOGY INVESTMENT AGREEMENTS Definitions of Terms Used in This Part § 37.1325 Periodic audit. An audit of... awards. Appendix C to this part describes what such an audit may cover. A periodic audit of a participant...

  16. 49 CFR 236.588 - Periodic test.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Periodic test. 236.588 Section 236.588..., Train Control and Cab Signal Systems Inspection and Tests; Locomotive § 236.588 Periodic test. Except as provided in § 236.586, periodic test of the automatic train stop, train control, or cab signal apparatus...

  17. 47 CFR 22.1035 - Construction period.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Construction period. 22.1035 Section 22.1035 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Offshore Radiotelephone Service § 22.1035 Construction period. The construction period (see § 22.142) for...

  18. Influence of the heat flux and of the gas on heat transfer and friction coefficients in a smooth cylindrical tube; Influence du flux de chaleur et de la nature du gaz sur les coefficients d'echange et le frottement dans un tube cylindrique lisse

    Energy Technology Data Exchange (ETDEWEB)

    Delpont, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-12-15

    The stainless steel tube used for the experiments is heated by means of d.c current; its inside diameter is 40 mm; its length is about 5.80 meters. Special core has been taken (heated rocket) to avoid heat loss and to provide very accurate measurements. The cooling gases tested are air and carbon dioxide at a pressure of 2.6 to 19 psi; the Reynolds number ranges from 70,000 to 10{sup 6}, the wall temperature and the heat flux reach respectively 430 deg C and 16 watts/cm{sup 2}. The Reynolds number Re{sub m}, Stanton number M{sub m} and friction coefficient f are computed by evaluating the physical properties of the gases at the mean temperature T{sub m}. For a given Reynolds number, a decrease of M{sub m} and of f is observed hen the heat flux increases, this decrease reaches 10 per cent in the experiments described. A formulation is proposed to express this effect in terms of a heat flow parameter (T{sub m} - T{sub m}) / T{sub p} used as a corrective factor (T{sub p} = wall temperature). The correlation formulae are: M{sub m} = 0.0168 Re{sub m}{sup -0.18} P{sub m}{sup -0.6} (1 - 0.4 [(T{sub p} - T{sub m}) / T{sub p}]) for air f = f{sub 0} (1 0.25 [(T{sub p} - T{sub m}) / T{sub p}]) for air M{sub m} = 0.0171 Re{sub m}{sup -0.18} P{sub m}{sup -0.6} (1 - 0.2 [(T{sub p} - T{sub m}) / T{sub p}]) for carbon dioxide f = f{sub 0} (1 - 0.20 [(T{sub p} - T{sub m}) / T{sub p}]) for carbon dioxide where f{sub 0} = the friction coefficient for isotherm flow. (author) [French] Le tube utilite a un diametre interieur de 40 mm; sa longueur est de 5,80 m environ; il est en acier inoxydable et chauffe par un courant continu. Des precautions particulieres (enceinte chauffante exterieure) ont ete prises pour eviter tout echange de chaleur avec le milieu exterieur et permettre des mesures extremement precises. Les gaz de refroidissement experimentes sont l'air et le gaz corbonique sous une pression de 1,8 a 13 hpz; les nombres de Reynolds vont de 70 000 a 10{sup 6}, la temperature de

  19. Law project modified by the Senate after urgency declaration relative to the electric and gas public utilities and to the power and gas companies; Projet de loi modifie par le Senat apres declaration d'urgence relatif au service public de l'electricite et du gaz et aux entreprises electriques et gazieres

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This document is the modifications made by the French Senate after the first reading of the law project adopted by the House of Commons and relative to the change of status of the power and gas public utilities in the framework of the deregulation of European energy markets. This law changes the juridical status of the two state monopolies Electricite de France (EdF) and Gaz de France (GdF) into two anonymous companies and creates two additional companies for the management of the power and gas networks. It ensures also the transposition of the European directives from June 26, 2003 (2003/54/CE and 2003/55/CE). It contains some proper dispositions and modifies various existing French laws, in particular the law no. 46-628 from April 8, 1946 about the electricity and gas nationalization and the law no. 2000-108 from February 10, 2000 relative to the modernization and development of the electric public utility. The document lists the modifications made by the Senate article by article. (J.S.)

  20. The Use of Fuel Gas as Stripping Medium in Atmospheric Distillation of Crude Oil L’utilisation de gaz combustible comme moyen d’extraction des fractions légères en distillation atmosphérique du pétrole brut

    Directory of Open Access Journals (Sweden)

    Plellis-Tsaltakis C.

    2011-09-01

    Full Text Available Stripping of petroleum fractions aims to remove the light ends that spoil some of their properties, such as the flash point. Stripping usually employs steam for that purpose. Except for steam, other substances can perform the same function, among them light hydrocarbons. In this article, we investigate the use of refinery fuel gas as stripping medium for a crude oil atmospheric distillation unit. L’extraction des fractions légères du pétrole vise à enlever les produits nuisibles à certaines propriétés comme le point d’éclair. Cette opération utilise habituellement de la vapeur d’eau. D’autres substances peuvent remplir la même fonction, comme les hydrocarbures légers. Dans cet article, on étudie l’utilisation du gaz combustible de la raffinerie comme moyen d’extraction des fractions légères dans une unité de distillation atmosphérique.

  1. Influence de la pression et de la non-idéalité des gaz dans le calcul d'un réacteur d'ammoniac Influence of Gas Pressure and Non-Iddeality on Designing an Ammonia Reactor

    Directory of Open Access Journals (Sweden)

    Scheiderman B.

    2006-11-01

    Full Text Available Le mélange gazeux qui parcourt un réacteur de synthèse d'ammoniac présente des écarts notables par rapport aux gaz idéaux. On a établi les équations de calcul d'un réacteur à gradient thermique optimum en tenant compte de l'influence de ces écarts sous trois pressions d'opération (150, 300 et 500 atm.. On a vérifié que les corrections principales à effectuer sont dues à la fugacité; les autres sont d'une importance moindre, et affectent surtout le contrôle du réacteur. En outre, on a mis en évidence l'influence considérable de la pression totale. The gaseous mixture flowing through an ommonia synthesis reactor shows considerable divergences from the behovior of ideal gases. These divergences are examined at three operating pressures (150, 300 and 500 atm, and the corresponding design equations for an optimum temperature progression are determined. The main diver gences are those caused by fugacity. The others are of lesser importance. At the same time, the great influence of total pressure is demonstrated.

  2. Project of law modified by the Senate relative to the electric and gas public utilities and to the electric and gas companies; Projet de loi modifie par le Senat relatif au service public de l'electricite et du gaz et aux entreprises electriques et gazieres

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This project of law aims to adapt the electricity and gas sector to the new economical context of opening of the energy markets to competition. It gives to energy companies the internal organization base necessary to warrant a high level of service and a transparent and non-discriminatory access of third parties to transport and distribution networks. These evolutions will allow Electricite de France (EdF) and Gaz de France (GdF) companies to compete on equal terms with their European competitors. It confirms first the prime role of public utility of both companies and then transposes the dispositions of the European directives relative to the organization of EdF and GdF integrated companies. It foresees the creation of two daughter companies for the management of energy transport activities. The project of law foresees also the change of the status of EdF and GdF companies and the reform of the retirement pensions of the personnel. This report presents the modifications added by the Senate to the text of law adopted at first reading by the House of Commons. (J.S.)

  3. Handgun waiting periods reduce gun deaths.

    Science.gov (United States)

    Luca, Michael; Malhotra, Deepak; Poliquin, Christopher

    2017-11-14

    Handgun waiting periods are laws that impose a delay between the initiation of a purchase and final acquisition of a firearm. We show that waiting periods, which create a "cooling off" period among buyers, significantly reduce the incidence of gun violence. We estimate the impact of waiting periods on gun deaths, exploiting all changes to state-level policies in the Unites States since 1970. We find that waiting periods reduce gun homicides by roughly 17%. We provide further support for the causal impact of waiting periods on homicides by exploiting a natural experiment resulting from a federal law in 1994 that imposed a temporary waiting period on a subset of states. Copyright © 2017 the Author(s). Published by PNAS.

  4. A highly specific test for periodicity

    Energy Technology Data Exchange (ETDEWEB)

    Ansmann, Gerrit, E-mail: gansmann@uni-bonn.de [Department of Epileptology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Helmholtz Institute for Radiation and Nuclear Physics, University of Bonn, Nussallee 14–16, 53115 Bonn (Germany); Interdisciplinary Center for Complex Systems, University of Bonn, Brühler Straße 7, 53175 Bonn (Germany)

    2015-11-15

    We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely, that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic time-continuous dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincaré sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its runtime grows asymptotically linear with the length of the time series.

  5. A highly specific test for periodicity

    International Nuclear Information System (INIS)

    Ansmann, Gerrit

    2015-01-01

    We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely, that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic time-continuous dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincaré sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its runtime grows asymptotically linear with the length of the time series

  6. Seismic isolation of two dimensional periodic foundations

    International Nuclear Information System (INIS)

    Yan, Y.; Mo, Y. L.; Laskar, A.; Cheng, Z.; Shi, Z.; Menq, F.; Tang, Y.

    2014-01-01

    Phononic crystal is now used to control acoustic waves. When the crystal goes to a larger scale, it is called periodic structure. The band gaps of the periodic structure can be reduced to range from 0.5 Hz to 50 Hz. Therefore, the periodic structure has potential applications in seismic wave reflection. In civil engineering, the periodic structure can be served as the foundation of upper structure. This type of foundation consisting of periodic structure is called periodic foundation. When the frequency of seismic waves falls into the band gaps of the periodic foundation, the seismic wave can be blocked. Field experiments of a scaled two dimensional (2D) periodic foundation with an upper structure were conducted to verify the band gap effects. Test results showed the 2D periodic foundation can effectively reduce the response of the upper structure for excitations with frequencies within the frequency band gaps. When the experimental and the finite element analysis results are compared, they agree well with each other, indicating that 2D periodic foundation is a feasible way of reducing seismic vibrations.

  7. Discrete symmetries in periodic-orbit theory

    International Nuclear Information System (INIS)

    Robbins, J.M.

    1989-01-01

    The application of periodic-orbit theory to systems which possess a discrete symmetry is considered. A semiclassical expression for the symmetry-projected Green's function is obtained; it involves a sum over classical periodic orbits on a symmetry-reduced phase space, weighted by characters of the symmetry group. These periodic orbits correspond to trajectories on the full phase space which are not necessarily periodic, but whose end points are related by symmetry. If the symmetry-projected Green's functions are summed, the contributions of the unperiodic orbits cancel, and one recovers the usual periodic-orbit sum for the full Green's function. Several examples are considered, including the stadium billiard, a particle in a periodic potential, the Sinai billiard, the quartic oscillator, and the rotational spectrum of SF 6

  8. How periodic are terahertz quantum cascade lasers?

    International Nuclear Information System (INIS)

    Kubis, T; Vogl, P

    2009-01-01

    We apply a novel non-equilibrium Green's function method for open quantum devices to analyze quantum cascade lasers. We find the carrier distribution in typical resonant phonon THz-QCLs to develop a periodicity that differs from the geometric periodicity of the QCL. We propose a design improvement that thermalizes electrons at threshold bias and thereby pins the electron density to the QCL periodicity.

  9. How periodic are terahertz quantum cascade lasers?

    Energy Technology Data Exchange (ETDEWEB)

    Kubis, T; Vogl, P, E-mail: tillmann.kubis@wsi.tum.d [Walter Schottky Institute, Technische Universitaet Muenchen, Am Coulombwall 3, 85748 Garching (Germany)

    2009-11-15

    We apply a novel non-equilibrium Green's function method for open quantum devices to analyze quantum cascade lasers. We find the carrier distribution in typical resonant phonon THz-QCLs to develop a periodicity that differs from the geometric periodicity of the QCL. We propose a design improvement that thermalizes electrons at threshold bias and thereby pins the electron density to the QCL periodicity.

  10. Southern hemisphere searches for short period pulsars

    International Nuclear Information System (INIS)

    Manchester, R.N.

    1984-01-01

    Two searches of the southern sky for short period pulsars are briefly described. The first, made using the 64-m telescope at Parkes, is sensitive to pulsars with periods greater than about 10 ms and the second, made using the Molonglo radio telescope, has sensitivity down to periods of about 1.5 ms. Four pulsars were found in the Parkes survey and none in the Molonglo survey, although analysis of the latter is as yet incomplete. 10 references, 1 figure, 2 tables

  11. Long-Period Variability in o Ceti

    Science.gov (United States)

    Templeton, Matthew R.; Karovska, Margarita

    2009-02-01

    We carried out a new and sensitive search for long-period variability in the prototype of the Mira class of long-period pulsating variables, o Ceti (Mira A), the closest and brightest Mira variable. We conducted this search using an unbroken light curve from 1902 to the present, assembled from the visual data archives of five major variable star observing organizations from around the world. We applied several time-series analysis techniques to search for two specific kinds of variability: long secondary periods (LSPs) longer than the dominant pulsation period of ~333 days, and long-term period variation in the dominant pulsation period itself. The data quality is sufficient to detect coherent periodic variations with photometric amplitudes of 0.05 mag or less. We do not find evidence for coherent LSPs in o Ceti to a limit of 0.1 mag, where the amplitude limit is set by intrinsic, stochastic, low-frequency variability of approximately 0.1 mag. We marginally detect a slight modulation of the pulsation period similar in timescale to that observed in the Miras with meandering periods, but with a much lower period amplitude of ±2 days. However, we do find clear evidence of a low-frequency power-law component in the Fourier spectrum of o Ceti's long-term light curve. The amplitude of this stochastic variability is approximately 0.1 mag at a period of 1000 days, and it exhibits a turnover for periods longer than this. This spectrum is similar to the red noise spectra observed in red supergiants.

  12. Epidural Analgesia in the Postoperative Period

    National Research Council Canada - National Science Library

    Mathsen, Curtis

    2001-01-01

    .... This descriptive study was conducted to determine which surgical patients experienced the most analgesia with the fewest side effects when receiving epidural analgesia in the postoperative period...

  13. Project 2nd Periodic Report - Section 2

    DEFF Research Database (Denmark)

    Healy, Mark; Knowles, Emma; Johnstone, Cameron

    The work described in this publication has received support from the European Community - Research Infrastructure Action under the FP7 “Capacities” Specific Programme through grant agreement number 262552, MaRINET. Project Periodic Report. 2nd Period: October 2012 – March 2014 inclusive.......The work described in this publication has received support from the European Community - Research Infrastructure Action under the FP7 “Capacities” Specific Programme through grant agreement number 262552, MaRINET. Project Periodic Report. 2nd Period: October 2012 – March 2014 inclusive....

  14. Periodic Continuing Disability Review Case Backlog

    Data.gov (United States)

    Social Security Administration — The Social Security Administration (SSA) conducts periodic CDRs to ensure that only those beneficiaries who remain disabled continue to receive monthly benefits. The...

  15. 38 CFR 3.252 - Annual income; pension; Mexican border period and later war periods.

    Science.gov (United States)

    2010-07-01

    ...; Mexican border period and later war periods. 3.252 Section 3.252 Pensions, Bonuses, and Veterans' Relief... Dependency, Income and Estate § 3.252 Annual income; pension; Mexican border period and later war periods. (a) Annual income limitations; old-law pension. Where the right to old-law pension is payable under section...

  16. The Cyrano program. 1 - description and operation of an irradiation device 'Cyrano'. 2 - results of the experiments Cyrano 1 and 2 (study of the EL 4 first-bach pencil); measurement of the thermal conductivity integral for UO{sub 2} sintered up to 2300 deg C; evolution of fission gases at constant power; Programme Cyrano. 1 - description et exploitation d'un dispositif d'irradiation ''cyrano''. 2 - resultats des experiences cyrano 1 et 2 (etude du crayon EL4 1. jeu). Mesure de l'integrale de conductibilite thermique d'UO{sub 2} fritte jusqu'a 2300 deg C. Evolution des gaz de fission a puissance constante

    Energy Technology Data Exchange (ETDEWEB)

    Stora, J P; Chenebault, P [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    Two rods of the type 'EL 4 first score' have been irradiated in 'Cyrano' capsules which are suited for continuous measurement of the nuclear power evolved and equipped with thermocouples. The variations of the integral of conductivity of sintered 96 per cent theoretical dense UO{sub 2} has been established until 2300 deg. C; these variations are coherent with those previously measured out-of-pile. The released fission gases have been recovered at different times during the irradiation: the kinetics of release of stable gases is such that, in the experimental conditions (T{sub surface} = 610 deg. C, {integral}{sub T{sub s}}{sup T{sub c}} kdT = 34.7 W cm{sup -1}) the fraction of released gases is still widely increasing after 12 days of irradiation. Numerous observations have been made on concentrations of rare gases locally present in the irradiated fuel. (authors) [French] L'irradiation de deux crayons combustibles type EL 4, 1er jeu, a ete menee a bien dans des capsules 'Cyrano' equipees de dispositifs de mesure continue de la puissance nucleaire et de plusieurs reperes de temperatures; la variation de l'integrale de conductibilite thermique de l'oxyde d'uranium fritte (96 pour cent d. th.) a ete tracee jusqu'a 2300 deg. C; la courbe representative de ces variations est coherente avec celle obtenue precedemment hors pile. Les gaz de fission apparus hors du combustible ont ete extraits du crayon a plusieurs reprises pendant l'experience: la cinetique d'accumulation des gaz stables est telle que dans les conditions etudiees (T{sub surface} = 610 deg. C, {integral}{sub T{sub s}}{sup T{sub c}} kdT = 34.7 W cm{sup -1}) la fraction des gaz degages est encore largement croissante apres 12 jours d'irradiation. De nombreuses observations ont ete recueillies sur la nature et la concentration des gaz rares presents en differents points du combustible irradie. (auteurs)

  17. 46 CFR 403.115 - Accounting period.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Accounting period. 403.115 Section 403.115 Shipping COAST GUARD (GREAT LAKES PILOTAGE), DEPARTMENT OF HOMELAND SECURITY GREAT LAKES PILOTAGE UNIFORM ACCOUNTING SYSTEM General § 403.115 Accounting period. Each Association subject to this part shall maintain...

  18. 18 CFR 367.5 - Accounting period.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Accounting period. 367.5 Section 367.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION... Instructions § 367.5 Accounting period. Each service company must keep its books on a monthly basis so that for...

  19. 24 CFR 221.775 - Option period.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Option period. 221.775 Section 221.775 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... § 221.775 Option period. The mortgagee may exercise its option to assign within one year following the...

  20. 42 CFR 409.60 - Benefit periods.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Benefit periods. 409.60 Section 409.60 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM HOSPITAL INSURANCE BENEFITS Scope of Hospital Insurance Benefits § 409.60 Benefit periods. (a) When benefit...

  1. 28 CFR 524.75 - Periodic review.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Periodic review. 524.75 Section 524.75... TRANSFER CLASSIFICATION OF INMATES Central Inmate Monitoring (CIM) System § 524.75 Periodic review. The Warden shall ensure that the status of an inmate's CIM assignment is considered at each program review...

  2. 50 CFR 424.21 - Periodic review.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Periodic review. 424.21 Section 424.21... SPECIES AND DESIGNATING CRITICAL HABITAT Revision of the Lists § 424.21 Periodic review. At least once every 5 years, the Secretary shall conduct a review of each listed species to determine whether it...

  3. Attractors for discrete periodic dynamical systems

    Science.gov (United States)

    John E. Franke; James F. Selgrade

    2003-01-01

    A mathematical framework is introduced to study attractors of discrete, nonautonomous dynamical systems which depend periodically on time. A structure theorem for such attractors is established which says that the attractor of a time-periodic dynamical system is the unin of attractors of appropriate autonomous maps. If the nonautonomous system is a perturbation of an...

  4. Discontinuous Spirals of Stable Periodic Oscillations

    DEFF Research Database (Denmark)

    Sack, Achim; Freire, Joana G.; Lindberg, Erik

    2013-01-01

    We report the experimental discovery of a remarkable organization of the set of self-generated periodic oscillations in the parameter space of a nonlinear electronic circuit. When control parameters are suitably tuned, the wave pattern complexity of the periodic oscillations is found to increase...

  5. Multi-periodic nanostructures for photon control

    DEFF Research Database (Denmark)

    Kluge, Christian; Adam, Jost; Barié, Nicole

    2014-01-01

    We propose multi-periodic nanostructures yielded by superposition of multiple binary gratings for wide control over photon emission in thin-film devices. We present wavelength- and angle-resolved photoluminescence measurements of multi-periodically nanostructured organic light-emitting layers...

  6. Quantized gauge invariant periodic TDHF solutions

    International Nuclear Information System (INIS)

    Kan, K.-K.; Griffin, J.J.; Lichtner, P.C.; Dworzecka, M.

    1979-01-01

    Time-dependent Hartree-Fock (TDHF) is used to study steady state large amplitude nuclear collective motions, such as vibration and rotation. As is well known the small amplitude TDHF leads to the RPA equation. The analysis of periodicity in TDHF is not trivial because TDHF is a nonlinear theory and it is not known under what circumstances a nonlinear theory can support periodic solutions. It is also unknown whether such periodic solution, if they exist, form a continuous or a discrete set. But, these properties may be important in obtaining the energy spectrum of the collective states from the TDHF description. The periodicity and Gauge Invariant Periodicity of solutions are investigated for that class of models whose TDHF solutions depend on time through two parameters. In such models TDHF supports a continuous family of periodic solutions, but only a discrete subset of these is gauge invariant. These discrete Gauge Invariant Periodic solutions obey the Bohr-Summerfeld quantization rule. The energy spectrum of the Gauge Invariant Periodic solutions is compared with the exact eigenergies in one specific example

  7. 20 CFR 410.501 - Payment periods.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Payment periods. 410.501 Section 410.501 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Payment of Benefits § 410.501 Payment periods. Benefits are paid to...

  8. The decreasing period of AG Phe

    International Nuclear Information System (INIS)

    Cerruti, M.A.

    1986-01-01

    Seven UBV photoelectric times of minimum light are presented. They shift the photographically known period 0 . d 613 to 0 . d 380. The improvement of the light elements leads to a reliable shortening of the period. A rough determination of the mass-ratio permitted to give an estimate of the mass transfer in the system. 13 refs., 1 fig., 1 tab. (author)

  9. Selecting Full-Text Undergraduate Periodicals Databases.

    Science.gov (United States)

    Still, Julie M.; Kassabian, Vibiana

    1999-01-01

    Examines how libraries and librarians can compare full-text general periodical indices, using ProQuest Direct, Periodical Abstracts (via Ovid), and EBSCOhost as examples. Explores breadth and depth of coverage; manipulation of results (email/download/print); ease of use (searching); and indexing quirks. (AEF)

  10. 20 CFR 655.205 - Recruitment period.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Recruitment period. 655.205 Section 655.205... FOREIGN WORKERS IN THE UNITED STATES Labor Certification Process for Logging Employment and Non-H-2A Agricultural Employment § 655.205 Recruitment period. (a) If the OFLC Administrator determines that the...

  11. Buffer Overflow Period in a MAP Queue

    Directory of Open Access Journals (Sweden)

    Andrzej Chydzinski

    2007-01-01

    Full Text Available The buffer overflow period in a queue with Markovian arrival process (MAP and general service time distribution is investigated. The results include distribution of the overflow period in transient and stationary regimes and the distribution of the number of cells lost during the overflow interval. All theorems are illustrated via numerical calculations.

  12. Shock dynamics in layered periodic media

    KAUST Repository

    Ketcheson, David I.; Leveque, Randall J.

    2012-01-01

    of shock waves in a one-dimensional periodic layered medium by a computational study of time-reversibility and entropy evolution. We find that periodic layered media tend to inhibit shock formation. For small initial conditions and large impedance variation

  13. Survival period, infectivity and morphological composition of ...

    African Journals Online (AJOL)

    Open Access DOWNLOAD FULL TEXT ... At the end of each maintenance period (hours), three clean albino mice were ... for up to 12 and 24 hours respectively were infective for the mice inoculation test. ... period (21.0days) higher peak parasitaemia (15-20 parasites per field) and higher population of slender forms.

  14. Online Periodic Table: A Cautionary Note

    Science.gov (United States)

    Izci, Kemal; Barrow, Lloyd H.; Thornhill, Erica

    2013-01-01

    The purpose of this study was (a) to evaluate ten online periodic table sources for their accuracy and (b) to compare the types of information and links provided to users. Limited studies have been reported on online periodic table (Diener and Moore 2011; Slocum and Moore in "J Chem Educ" 86(10):1167, 2009). Chemistry students'…

  15. The periodic table of elementary particles

    International Nuclear Information System (INIS)

    Bhattacharjee, B.J.

    1994-01-01

    It is shown that a periodic classification of elementary particles (eps) may be done with the basic properties of eps: viz. mass, spin and parity. Further application of spacing rule and GMO mass formulae show repetitions at very regular intervals. It is found that properties of eps are periodic function of rest mass. (author). 17 refs., 6 tabs

  16. The periodic table of elementary particles

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, B J [St. Anthony' s College, Shillong (India). Dept. of Physics

    1994-01-01

    It is shown that a periodic classification of elementary particles (eps) may be done with the basic properties of eps: viz. mass, spin and parity. Further application of spacing rule and GMO mass formulae show repetitions at very regular intervals. It is found that properties of eps are periodic function of rest mass. (author). 17 refs., 6 tabs.

  17. 12 CFR 226.7 - Periodic statement.

    Science.gov (United States)

    2010-01-01

    ... consumer with a periodic statement that discloses the following items, to the extent applicable: (a... convenience of the user, the revised text is set forth as follows: § 226.7 Periodic statement. (a) Rules... consumers may obtain from the creditor more information about the balance computation method and how...

  18. 5 CFR 9901.512 - Probationary periods.

    Science.gov (United States)

    2010-01-01

    ... 9901.512 Administrative Personnel DEPARTMENT OF DEFENSE HUMAN RESOURCES MANAGEMENT AND LABOR RELATIONS SYSTEMS (DEPARTMENT OF DEFENSE-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF DEFENSE NATIONAL SECURITY... Probationary periods. (a) Initial probationary period. (1) An employee who is given a career, career...

  19. Resonances in a periodically driven bosonic system

    NARCIS (Netherlands)

    Quelle, Anton; de Morais Smith, Cristiane

    2017-01-01

    Periodically driven systems are a common topic in modern physics. In optical lattices specifically, driving is at the origin of many interesting phenomena. However, energy is not conserved in driven systems, and under periodic driving, heating of a system is a real concern. In an effort to better

  20. Almost periodic Hamiltonians: an algebraic approach

    International Nuclear Information System (INIS)

    Bellissard, J.

    1981-07-01

    We develop, by analogy with the study of periodic potential, an algebraic theory for almost periodic hamiltonians, leading to a generalized Bloch theorem. This gives rise to results concerning the spectral measures of these operators in terms of those of the corresponding Bloch hamiltonians

  1. Period Variations for the Cepheid VZ Cyg

    Science.gov (United States)

    Sirorattanakul, Krittanon; Engle, Scott; Pepper, Joshua; Wells, Mark; Laney, Clifton D.; Rodriguez, Joseph E.; Stassun, Keivan G.

    2017-12-01

    The Cepheid Period-Luminosity law is a key rung on the extragalactic distance ladder. However, numerous Cepheids are known to undergo period variations. Monitoring, refining, and understanding these period variations allows us to better determine the parameters of the Cepheids themselves and of the instability strip in which they reside, and to test models of stellar evolution. VZ Cyg, a classical Cepheid pulsating at ˜4.864 days, has been observed for over 100 years. Combining data from literature observations, the Kilodegree Extremely Little Telescope (KELT) transit survey, and new targeted observations with the Robotically Controlled Telescope (RCT) at Kitt Peak, we find a period change rate of dP/dt = -0.0642 ± 0.0018 s yr-1. However, when only the recent observations are examined, we find a much higher period change rate of dP/dt = -0.0923 ± 0.0110 s yr-1. This higher rate could be due to an apparent long-term (P ≈ 26.5 years) cyclic period variation. The possible interpretations of this single Cepheid’s complex period variations underscore both the need to regularly monitor pulsating variables and the important benefits that photometric surveys such as KELT can have on the field. Further monitoring of this interesting example of Cepheid variability is recommended to confirm and better understand the possible cyclic period variations. Further, Cepheid timing analyses are necessary to fully understand their current behaviors and parameters, as well as their evolutionary histories.

  2. David's Understanding of Functions and Periodicity

    Science.gov (United States)

    Gerson, Hope

    2008-01-01

    This is a study of David, a senior enrolled in a high school precalculus course. David's understandings of functions and periodicity was explored, through clinical interviews and contextualized through classroom observations. Although David's precalculus class was traditional his understanding of periodic functions was unconventional David engaged…

  3. Periodization Theory: Confronting an Inconvenient Truth.

    Science.gov (United States)

    Kiely, John

    2018-04-01

    Periodization theory has, over the past seven decades, emerged as the preeminent training planning paradigm. The philosophical underpinnings of periodization theory can be traced back to the integration of diverse shaping influences, whereby coaching beliefs and traditions were blended with historically available scientific insights and contextualized against pervading social planning models. Since then, many dimensions of elite preparation have evolved significantly, as driven by a combination of coaching innovations and science-led advances in training theory, techniques, and technologies. These advances have been incorporated into the fabric of the pre-existing periodization planning framework, yet the philosophical assumptions underpinning periodization remain largely unchallenged and unchanged. One particularly influential academic sphere of study, the science of stress, particularly the work of Hans Selye, is repeatedly cited by theorists as a central pillar upon which periodization theory is founded. A fundamental assumption emanating from the early stress research is that physical stress is primarily a biologically mediated phenomenon: a presumption translated to athletic performance contexts as evidence that mechanical training stress directly regulates the magnitude of subsequent 'fitness' adaptations. Interestingly, however, since periodization theory first emerged, the science of stress has evolved extensively from its historical roots. This raises a fundamental question: if the original scientific platform upon which periodization theory was founded has disintegrated, should we critically re-evaluate conventional perspectives through an updated conceptual lens? Realigning periodization philosophy with contemporary stress theory thus presents us with an opportunity to recalibrate training planning models with both contemporary scientific insight and progressive coaching practice.

  4. Periodic and secular changes in SS 433

    International Nuclear Information System (INIS)

    Collins, G.W.; Newsom, G.H.

    1983-01-01

    The recent history of SS 433 is reviewed with particular attention being given to the discovery of the periodic phenomena displayed by this object. Several periods ranging from days to months are established as being present in the spectrum of the ''moving'' lines as well as in other aspects of the emission from the object. In addition evidence for secular change in some of the defining parameters of the system is presented. Although these secular changes may eventually prove to be periodic on a rather long time scale, some interpretation of both the periodic and secular phenomena is possible. It is shown that it is possible to interpret all the known periodic phenomena in terms of a processing object responding to the time-varying torques that one would expect in a binary system

  5. Hypokalemic periodic paralysis: Three rare secondary causes

    Directory of Open Access Journals (Sweden)

    Prasanna Eswaradass Venkatesan

    2015-01-01

    Full Text Available Periodic paralysis is a rare neuromuscular disorder, related to a defect in muscle ion channels, characterized by episodes of painless muscle weakness, which may be precipitated by heavy exercise, fasting, or high-carbohydrate meals. Hypokalemic periodic paralysis may be familial (primary or secondary. Here, we report three cases of secondary causes of hypokalemic periodic paralysis. On evaluation, case 1 had distal renal tubular acidosis (RTA due to Sjogren′s syndrome, case 2 had drug induced proximal RTA (Fanconi′s syndrome and case 3 had thyrotoxicosis. Clinician must be aware of causes of secondary PP as recognition and diagnosis can completely prevent further attacks of periodic paralysis. Each of the above case is rare, but completely treatable if diagnosed. Low dose steroids with bicarbonate replacement in case 1, stopping tenofovir in case 2 and carbimazole therapy in case 3 prevented further attacks of periodic paralysis and cardiopulmonary complications.

  6. Periodic-cylinder vesicle with minimal energy

    International Nuclear Information System (INIS)

    Xiao-Hua, Zhou

    2010-01-01

    We give some details about the periodic cylindrical solution found by Zhang and Ou-Yang in [1996 Phys. Rev. E 53 4206] for the general shape equation of vesicle. Three different kinds of periodic cylindrical surfaces and a special closed cylindrical surface are obtained. Using the elliptic functions contained in mathematic, we find that this periodic shape has the minimal total energy for one period when the period–amplitude ratio β ≈ 1.477, and point out that it is a discontinuous deformation between plane and this periodic shape. Our results also are suitable for DNA and multi-walled carbon nanotubes (MWNTs). (cross-disciplinary physics and related areas of science and technology)

  7. Measurements and Application of Partition Coefficients of Compounds Suitable for Tracing Gas Injected Into Oil Reservoirs Mesures et applications des coefficients de partage de composants utilisables comme gaz traceurs injectés dans des réservoirs de pétrole

    Directory of Open Access Journals (Sweden)

    Dugstad O.

    2006-11-01

    Full Text Available Tracing of injection gas in oil reservoirs is a technique used to improve the description of permeability distributions in situ. Results from dynamic laboratory experiments of gas tracers are reported. Gas tracers are delayed when flooding through a reservoir by the partitioning into the oil phase. A knowledge of this effect is important to optimize the interpretation of field tracer tests. The partition is quantified by the partition coefficient K. Two chemical tracers perfluoromethylcyclopentane (PMCP and perfluoromethylcyclohexane (PMCH and the radioactive 14C labelled ethane have been studied here. The two chemical compounds are new as reservoir tracers and no field results with these tracers are reported in the open literature. Our group has, however, recently applied these compound successfully as tracers in a North Sea reservoir. Les traceurs représentent un outil précieux pour améliorer la description des gisements. On les a utilisés pour obtenir des renseignements sur la configuration de l'écoulement des fluides injectés et sur leur vitesse, sur l'instant de percé des venues d'eau et sur leur origine précise, sur les traitements d'amélioration du balayage, sur les hétérogénéités importantes telles que fractures, barrières d'écoulement et stratifications de la perméabilité. Dans les gisements importants comportant plusieurs puits de production et plusieurs puits d'injection, il est donc souhaitable de disposer de plusieurs traceurs afin de pouvoir injecter différents traceurs ou mélanges de traceurs dans les différents puits. L'article présenté ici est une contribution a l'effort fait pour étendre le nombre de gaz traceurs fiables applicables aux gisements. L'article présente les résultats d'essais dynamiques en laboratoires dans lesquels on injecte des traceurs à travers un milieu poreux. Lorsqu'ils traversent un réservoir, les gaz traceurs sont retardés du fait de leur ségrégation dans la phase huile. La

  8. Variable-Period Undulators for Synchrotron Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai

    2005-02-22

    A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

  9. Variable-Period Undulators For Synchrotron Radiation

    Science.gov (United States)

    Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai

    2005-02-22

    A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

  10. Optimal glucose management in the perioperative period.

    Science.gov (United States)

    Evans, Charity H; Lee, Jane; Ruhlman, Melissa K

    2015-04-01

    Hyperglycemia is a common finding in surgical patients during the perioperative period. Factors contributing to poor glycemic control include counterregulatory hormones, hepatic insulin resistance, decreased insulin-stimulated glucose uptake, use of dextrose-containing intravenous fluids, and enteral and parenteral nutrition. Hyperglycemia in the perioperative period is associated with increased morbidity, decreased survival, and increased resource utilization. Optimal glucose management in the perioperative period contributes to reduced morbidity and mortality. To readily identify hyperglycemia, blood glucose monitoring should be instituted for all hospitalized patients. Published by Elsevier Inc.

  11. Convectons in periodic and bounded domains

    International Nuclear Information System (INIS)

    Mercader, Isabel; Batiste, Oriol; Alonso, Arantxa; Knobloch, Edgar

    2010-01-01

    Numerical continuation is used to compute spatially localized convection in a binary fluid with no-slip laterally insulating boundary conditions and the results are compared with the corresponding ones for periodic boundary conditions (PBC). The change in the boundary conditions produces a dramatic change in the snaking bifurcation diagram that describes the organization of localized states with PBC: the snaking branches turn continuously into a large amplitude state that resembles periodic convection with defects at the sidewalls. Odd parity convectons are more affected by the boundary conditions since the sidewalls suppress the horizontal pumping action that accompanies these states in spatially periodic domains.

  12. Convectons in periodic and bounded domains

    Energy Technology Data Exchange (ETDEWEB)

    Mercader, Isabel; Batiste, Oriol; Alonso, Arantxa [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, Barcelona (Spain); Knobloch, Edgar [Department of Physics, University of California, Berkeley, CA 94720 (United States)

    2010-04-15

    Numerical continuation is used to compute spatially localized convection in a binary fluid with no-slip laterally insulating boundary conditions and the results are compared with the corresponding ones for periodic boundary conditions (PBC). The change in the boundary conditions produces a dramatic change in the snaking bifurcation diagram that describes the organization of localized states with PBC: the snaking branches turn continuously into a large amplitude state that resembles periodic convection with defects at the sidewalls. Odd parity convectons are more affected by the boundary conditions since the sidewalls suppress the horizontal pumping action that accompanies these states in spatially periodic domains.

  13. Diffraction Theory and Almost Periodic Distributions

    Science.gov (United States)

    Strungaru, Nicolae; Terauds, Venta

    2016-09-01

    We introduce and study the notions of translation bounded tempered distributions, and autocorrelation for a tempered distribution. We further introduce the spaces of weakly, strongly and null weakly almost periodic tempered distributions and show that for weakly almost periodic tempered distributions the Eberlein decomposition holds. For translation bounded measures all these notions coincide with the classical ones. We show that tempered distributions with measure Fourier transform are weakly almost periodic and that for this class, the Eberlein decomposition is exactly the Fourier dual of the Lebesgue decomposition, with the Fourier-Bohr coefficients specifying the pure point part of the Fourier transform. We complete the project by looking at few interesting examples.

  14. Attractors of the periodically forced Rayleigh system

    Directory of Open Access Journals (Sweden)

    Petre Bazavan

    2011-07-01

    Full Text Available The autonomous second order nonlinear ordinary differential equation(ODE introduced in 1883 by Lord Rayleigh, is the equation whichappears to be the closest to the ODE of the harmonic oscillator withdumping.In this paper we present a numerical study of the periodic andchaotic attractors in the dynamical system associated with the generalized Rayleigh equation. Transition between periodic and quasiperiodic motion is also studied. Numerical results describe the system dynamics changes (in particular bifurcations, when the forcing frequency is varied and thus, periodic, quasiperiodic or chaotic behaviour regions are predicted.

  15. Periodicity in Age-Resolved Populations

    Science.gov (United States)

    Esipov, Sergei

    We discuss the interplay between the non-linear diffusion and age-resolved population dynamics. Depending on the age properties of collective migration the system may exhibit continuous joint expansion of all ages or continuous expansion with age segregation. Between these two obvious limiting regimes there is an interesting window of periodic expansion, which has been previously used by us in modeling bacterial colonies of Proteus mirabilis. In order to test whether the age-dependent collective migration leads to periodicity in other systems we performed a Fourier analysis of historical data on ethnic expansions and found multiple co-existing periods of activity.

  16. Periodic solutions of dissipative systems revisited

    Directory of Open Access Journals (Sweden)

    Górniewicz Lech

    2006-01-01

    Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.

  17. Periodic solutions of dissipative systems revisited

    Directory of Open Access Journals (Sweden)

    Lech Górniewicz

    2006-05-01

    Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.

  18. 77 FR 73452 - Grace Period Study

    Science.gov (United States)

    2012-12-10

    ... survey may be distributed in waves for convenience. The Grace Period Study survey will be an electronic... information that is used for sampling purposes will be maintained in a separate file from the quantitative...

  19. Time-Varying Periodicity in Intraday Volatility

    DEFF Research Database (Denmark)

    Andersen, Torben Gustav; Thyrsgaard, Martin; Todorov, Viktor

    We develop a nonparametric test for deciding whether return volatility exhibits time-varying intraday periodicity using a long time-series of high-frequency data. Our null hypothesis, commonly adopted in work on volatility modeling, is that volatility follows a stationary process combined...... with a constant time-of-day periodic component. We first construct time-of-day volatility estimates and studentize the high-frequency returns with these periodic components. If the intraday volatility periodicity is invariant over time, then the distribution of the studentized returns should be identical across...... with estimating volatility moments through their sample counterparts. Critical values are computed via easy-to-implement simulation. In an empirical application to S&P 500 index returns, we find strong evidence for variation in the intraday volatility pattern driven in part by the current level of volatility...

  20. Multi-Period Trading via Convex Optimization

    DEFF Research Database (Denmark)

    Boyd, Stephen; Busseti, Enzo; Diamond, Steve

    2017-01-01

    We consider a basic model of multi-period trading, which can be used to evaluate the performance of a trading strategy. We describe a framework for single-period optimization, where the trades in each period are found by solving a convex optimization problem that trades off expected return, risk......, transaction cost and holding cost such as the borrowing cost for shorting assets. We then describe a multi-period version of the trading method, where optimization is used to plan a sequence of trades, with only the first one executed, using estimates of future quantities that are unknown when the trades....... In this paper, we do not address a critical component in a trading algorithm, the predictions or forecasts of future quantities. The methods we describe in this paper can be thought of as good ways to exploit predictions, no matter how they are made. We have also developed a companion open-source software...

  1. Optimization on replacement period of plant equipment

    International Nuclear Information System (INIS)

    Kasai, Masao; Asano, Hiromi

    2002-01-01

    Optimization of the replacement period of plant equipment is one of the main items to rationalize the activities on plant maintenance. There are several models to replace the equipment and the formulations for optimizing the replacement period are different among these models. In this study, we calculated the optimum replacement periods for some equipment parts based on the replacement models and found that the optimum solutions are not so largely differ from the replacement models as far as the replacement period is not so large. So we will be able to use the most usable model especially in the early phase of rationalization on plant maintenance, since there are large uncertainties in data for optimization. (author)

  2. Early and Periodic Screening, Diagnosis and Treatment

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Early and Periodic Screening, Diagnostic and Treatment (EPSDT) benefit provides comprehensive and preventive health care services for children under age 21 who...

  3. 12 CFR 219.24 - Retention period.

    Science.gov (United States)

    2010-01-01

    ... PROVIDING FINANCIAL RECORDS; RECORDKEEPING REQUIREMENTS FOR CERTAIN FINANCIAL RECORDS (REGULATION S... period of time, taking into consideration the nature of the record and the amount of time that has...

  4. The period-luminosity relation for Cepheids

    International Nuclear Information System (INIS)

    Brodie, J.P.

    1980-01-01

    Numerical simulations of the empirical determination of the period-luminosity-colour relation for classical Cepheids are presented. In this study the quantitative effects of random errors, reddening, sample size and the presence of both colour and period cut-offs (imposed by the finite extent of the instability strip) on the observational redetermination of the original relation are evaluated. Both random errors in the photometry and correlated errors in the reddening corrections are shown to have systematic effects. Especially sensitive to these errors is the colour coefficient in the period-luminosity-colour relation, where the ratio of the error to the width of the instability strip is the determining factor. With present observations only broad confidence limits can be placed on present knowledge of the intrinsic period-luminosity-colour relation and/or its variations from galaxy to galaxy. (author)

  5. Genetics Home Reference: hypokalemic periodic paralysis

    Science.gov (United States)

    ... M, Franques J, Bendahhou S, Lory P, Hainque B, Fournier E, Nicole S, Fontaine B. Hypokalemic Periodic Paralysis. 2002 ... related congenital muscular dystrophy Melorheostosis Rhabdoid tumor predisposition syndrome All New & Updated Pages Reviewed : October 2017 Published : ...

  6. The ACM Periodical Bank: A Retrospective View.

    Science.gov (United States)

    Clarke, Jack A.

    1980-01-01

    Evaluates a cooperative venture in interlibrary lending of periodicals planned and executed by ten midwestern colleges. The study traces the consortium's history from 1967 to the present, describing successes and problems. (RAA)

  7. Concurrent hypokalemic periodic paralysis and bipolar disorder

    Directory of Open Access Journals (Sweden)

    Chia-Lin Lin

    2015-01-01

    Full Text Available Primary periodic paralysis is a rare autosomal dominant disorder of ion-channel dysfunction, manifested by episodic flaccid paresis secondary to abnormal sarcolemma excitability. Membrane destabilization involving Na, K-ATPase has been hypothesized to be a biological etiology of the bipolar disorder (BD and the mechanisms underlying lithium therapy have been linked to it. To date, there has been only one reported case of BD comorbid with periodic paralysis. Herein, we reported another case of concurrent bipolar mania and hypokalemic periodic paralysis (HPP, one special form of periodic paralysis. Consistent with the previous case, our patient responded well to lithium treatment for both bipolar mania and HPP. This might provide some support to the hypothesis that the therapeutic effects of lithium in both BD and HPP could be due to the correction of the underlying common pathophysiology.

  8. Ecological periodic tables: In principle and practice

    Science.gov (United States)

    The chemical periodic table, the Linnaean system of classification and the Hertzsprung-Russell diagram are iconic information organizing structure in chemistry, biology and astronomy, respectively, because they are simple, exceptionally useful and they foster the expansion of sci...

  9. Galactic Dark Matter and Terrestrial Periodicities

    National Research Council Canada - National Science Library

    Clube, S

    1998-01-01

    .... The Earth may thus be regarded as a probe of the disc environment; and to account for the periodicity, the Galactic disc is required to have a substantial dark matter component ( approx .15 molar mass/cu pc...

  10. Global bioevents and the question of periodicity

    Science.gov (United States)

    Sepkoski, J. John

    The hypothesis of periodicity in extinction is an empirical claim that extinction events, while variable in magnitude, are regular in timing and therefore are serially dependent upon some single, ultimate cause with clocklike behavior. This hypothesis is controversal, in part because of questions regarding the identity and timing of certain extinction events and because of speculations concerning possible catastrophic extraterrestrial forcing mechanisms. New data on extinctions of marine animal genera are presented that display a high degree of periodicity in the Mesozoic and Cenozoic as well as a suggestion of nonstationary periodicity in the late Paleozoic. However, no periodicity is evident among the as yet poorly documented extinction events of the early and middle Paleozoic.

  11. Periodical test program in depth revision

    International Nuclear Information System (INIS)

    Feltin, C.; Zermizoglou, R.

    1987-11-01

    Inspection visits made to different sites during 1980 and 1981 evidenced the need to extend and define more precisely the periodical tests performed on safety related systems; thus Electricite de France was requested by the Safety Authorities to re-examine the periodical test program for all safety related systems. This paper presents the methodology adopted by Electricite de France in order to perform an exhaustive analysis of the periodical test program for the 900 and 1300 MWe plants, and the organization set up at the IPSN at one hand and Electricite de France on the other hand for the purpose of elaborating a periodical test program which would be ratified by the Safety Authorities

  12. Toward an Organic Chemist's Periodic Table.

    Science.gov (United States)

    Hall, H. K., Jr.

    1980-01-01

    An analogy between electron transfer reactions of the elements and those of organic molecules is offered. Examples of organic electron transfer reactions are presented. The rationale of constructing an organic chemists' periodic table is also discussed. (HM)

  13. Theodore William Richards and the Periodic Table

    Science.gov (United States)

    Conant, James B.

    1970-01-01

    Discusses the contribution of Theodore Richards to the accurate determination of atomic weights of copper and other elements; his major contribution was to the building of the definitive periodic table of the elements. (BR)

  14. Spectral properties of almost-periodic Hamiltonians

    International Nuclear Information System (INIS)

    Lima, R.

    1983-12-01

    We give a description of some spectral properties of almost-periodic hamiltonians. We put the stress on some particular points of the proofs of the existence of absolutely continuous or pure point spectrum [fr

  15. Astrobee Periodic Technical Review (PTR) Delta 3

    Science.gov (United States)

    Provencher, Christopher; Smith, Marion F.; Smith, Ernest Everett; Bualat, Maria Gabriele; Barlow, Jonathan Spencer

    2017-01-01

    Astrobee is a free flying robot for the inside of the International Space Station (ISS). The Periodic Technical Review (PTR) delta 3 is the final design review of the system presented to stakeholders.

  16. Periodic words connected with the Fibonacci words

    Directory of Open Access Journals (Sweden)

    G. M. Barabash

    2016-06-01

    Full Text Available In this paper we introduce two families of periodic words (FLP-words of type 1 and FLP-words of type 2 that are connected with the Fibonacci words and investigated their properties.

  17. Broiler adaptation to post-hatching period

    Directory of Open Access Journals (Sweden)

    Maiorka Alex

    2006-01-01

    Full Text Available In the latest years more attention has been given to mechanisms for bird adaptation at post-hatching period by management of environmental conditions and formulations of diets offered during this period when digestive, immune, and thermo-regulating systems suffer slight changes. In post-hatching period, digestive system is anatomically complete, but its functionality is still immature in relation to adult birds. The chick immunity depends on maternal antibodies transferred to egg just before laying. In addition, variations within thermal comfort zone might affect initial development of chick. For example, high temperatures may induce hyperthermia with dehydration, while low temperatures may lead to hypothermia responsible by pulmonary hypertension syndrome. In conclusion, productivity might be enhanced when good conditions are offered to chicks during the period from last embryo development to first days after hatching.

  18. Prognosis following cancer surgery during holiday periods.

    Science.gov (United States)

    Lagergren, Jesper; Mattsson, Fredrik; Lagergren, Pernilla

    2017-11-15

    Surgery is the mainstay curative treatment in most cancer. We aimed to test the new hypothesis that cancer surgery performed during holiday periods is associated with worse long-term prognosis than for non-holiday periods. This nationwide Swedish population-based cohort study included 228,927 patients during 1997-2014 who underwent elective resectional surgery for a cancer where the annual number of resections was over 100. The 16 eligible cancer sites were grouped into 10 cancer groups. The exposure, holiday periods, was classified as wide (14-weeks) or narrow (7-weeks). Surgery conducted inside versus outside holiday periods was compared regarding overall disease-specific (main outcome) and overall all-cause (secondary outcome) mortality. Cox regression provided hazard ratios (HR) with 95% confidence intervals (CI) adjusted for age, sex, comorbidity, hospital volume, calendar period and tumor stage. Surgery conducted during wide and narrow holiday periods were associated with increased HRs of disease-specific mortality for cancer of the breast (HR 1.08, 95% CI 1.03-1.13 and HR 1.06, 95% CI 1.01-1.12) and possibly of cancer of the liver-pancreas-bile ducts (HR 1.09, 95% CI 0.99-1.20 and HR 1.12, 95% CI 0.99-1.26). Sub-groups with cancer of the colon-rectum, head-and-neck, prostate, kidney-urine bladder and thyroid also experienced statistically significantly worse prognosis following surgery conducted during holiday periods. No influence of surgery during holiday was detected for cancer of the esophagus-stomach, lung or ovary-uterus. All-cause HRs were similar to the disease-specific HRs. The prognosis following cancer surgery might not be fully maintained during holiday periods for all cancer sites. © 2017 UICC.

  19. Entanglement of periodic anisotropic XY chains

    International Nuclear Information System (INIS)

    Zhang Lifa; Tong Peiqing

    2005-01-01

    By using the concept of concurrence, the entanglement of periodic anisotropic XY chains in a transverse field is studied numerically. It is found that the derivatives ∂ λ C(1) of nearest-neighbour concurrence diverge at quantum critical points. By proper scaling, we found that all the derivatives ∂ λ C(1) for periodic XY chains in the vicinity of quantum critical points have the same behaviours as that of a uniform chain

  20. Coupled mode theory of periodic waveguides arrays

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Chigrin, Dmitry N.

    We apply the scalar coupled mode theory to the case of waveguides array consisting om two periodic waveguides. One of the waveguides is arbitrary shifted along another. A longitudinal shift acts as a parameter in the coupled mode theory. The proposed theory explains peculiarities of modes dispers...... dispersion and transmission in coupled periodic waveguides systems. Analytical results are compared with the numerical ones obtained by the plane wave expansion and FDTD methods....

  1. IUPAC Periodic Table of the Isotopes

    Science.gov (United States)

    Holden, N.E.; Coplen, T.B.; Böhlke, J.K.; Wieser, M.E.; Singleton, G.; Walczyk, T.; Yoneda, S.; Mahaffy, P.G.; Tarbox, L.V.

    2011-01-01

    For almost 150 years, the Periodic Table of the Elements has served as a guide to the world of elements by highlighting similarities and differences in atomic structure and chemical properties. To introduce students, teachers, and society to the existence and importance of isotopes of the chemical elements, an IUPAC Periodic Table of the Isotopes (IPTI) has been prepared and can be found as a supplement to this issue.

  2. Periodicity and Immortality in Reversible Computing

    OpenAIRE

    Kari , Jarkko; Ollinger , Nicolas

    2008-01-01

    Additional material available on the web at http://www.lif.univ-mrs.fr/~nollinge/rec/gnirut/; We investigate the decidability of the periodicity and the immortality problems in three models of reversible computation: reversible counter machines, reversible Turing machines and reversible one-dimensional cellular automata. Immortality and periodicity are properties that describe the behavior of the model starting from arbitrary initial configurations: immortality is the property of having at le...

  3. PERIODIC SIGNALS IN BINARY MICROLENSING EVENTS

    International Nuclear Information System (INIS)

    Guo, Xinyi; Stefano, Rosanne Di; Esin, Ann; Taylor, Jeffrey

    2015-01-01

    Gravitational microlensing events are powerful tools for the study of stellar populations. In particular, they can be used to discover and study a variety of binary systems. A large number of binary lenses have already been found through microlensing surveys and a few of these systems show strong evidence of orbital motion on the timescale of the lensing event. We expect that more binary lenses of this kind will be detected in the future. For binaries whose orbital period is comparable to the event duration, the orbital motion can cause the lensing signal to deviate drastically from that of a static binary lens. The most striking property of such light curves is the presence of quasi-periodic features, which are produced as the source traverses the same regions in the rotating lens plane. These repeating features contain information about the orbital period of the lens. If this period can be extracted, then much can be learned about the lensing system even without performing time-consuming, detailed light-curve modeling. However, the relative transverse motion between the source and the lens significantly complicates the problem of period extraction. To resolve this difficulty, we present a modification of the standard Lomb–Scargle periodogram analysis. We test our method for four representative binary lens systems and demonstrate its efficiency in correctly extracting binary orbital periods

  4. Interference pattern period measurement at picometer level

    Science.gov (United States)

    Xiang, Xiansong; Wei, Chunlong; Jia, Wei; Zhou, Changhe; Li, Minkang; Lu, Yancong

    2016-10-01

    To produce large scale gratings by Scanning Beam Interference Lithography (SBIL), a light spot containing grating pattern is generated by two beams interfering, and a scanning stage is used to drive the substrate moving under the light spot. In order to locate the stage at the proper exposure positions, the period of the Interference pattern must be measured accurately. We developed a set of process to obtain the period value of two interfering beams at picometer level. The process includes data acquisition and data analysis. The data is received from a photodiode and a laser interferometer with sub-nanometer resolution. Data analysis differs from conventional analyzing methods like counting wave peaks or using Fourier transform to get the signal period, after a preprocess of filtering and envelope removing, the mean square error is calculated between the received signal and ideal sinusoid waves to find the best-fit frequency, thus an accuracy period value is acquired, this method has a low sensitivity to amplitude noise and a high resolution of frequency. With 405nm laser beams interfering, a pattern period value around 562nm is acquired by employing this process, fitting diagram of the result shows the accuracy of the period value reaches picometer level, which is much higher than the results of conventional methods.

  5. Physical explanation of the periodic table.

    Science.gov (United States)

    Ostrovsky, V N

    2003-05-01

    The Periodic Table of the elements, the most important generalization in chemistry, is often considered as a representative special case in the study of the relation between chemistry and physics. Its quantum interpretation was initiated, but not completed, by Niels Bohr. In this paper, post-Bohr conceptual developments are discussed from historical and epistemological points of view. The difference between high-precision numerical calculations for individual atoms and the theory of the periodic system as a whole is emphasized. Periodic laws met in Nature are not restricted to the chemical Periodic Table. A comparative study of these laws makes it possible to single out essential features that define the particular pattern of periodicity. It is shown that the periodic system of neutral ground state atoms now has a firm nonempirical quantum-theoretical basis. Alternative approaches, based on group theory and other mathematical schemes, are briefly discussed. It is argued that, while quantum theory is capable of fully accurate calculations for relatively simple atoms or molecular objects, the complexity of polyatomic molecules and chemical reactions guarantees the flourishing of chemistry as a separate scientific discipline.

  6. La fonction logistique, un outil performant d'analyse et de prévision à moyen terme. Application à la production de pétrole et de gaz aux Etats-Unis, en URSS et dans d'autres pays The Logistic Function, an Efficient Medium-Range Analysis and Forecasting Method

    Directory of Open Access Journals (Sweden)

    Seguret J.

    2006-11-01

    Full Text Available A partir de la similitude observée entre l'évolution de la production pétrolière d'un pays et celle de la pénétration d'un produit dans un marché (fonction logistique, l'auteur expose le principe d'une méthode originale qui permet, sous certaines conditions, de prévoir quelle sera la production annuelle probable d'un pays producteur à un horizon de 10 à 15 ans. La validité de cette méthode est d'abord démontrée sur l'exemple de la production pétrolière aux Etats-Unis. Elle est ensuite illustrée par les résultats obtenus pour un certain nombre de pays : production future de gaz aux Etats-Unis, production pétrolière future du Canada, de l'URSS, du Venezuela et de l'ensemble du monde hors Moyen-Orient. On the basis of the similarity observed between the variation in the petroleum production of a country and that of the penetration of a product into the market (logistic function, this article describes the principle of an original method that can be used, under certain conditions, to forecast the probable annual production of a producing country in 10 to 15 years. The validity of this method is first demonstrated for the example of oil production in the United States. It is then illustrated by results obtained for various other countries, i. e. future gas production in the United States, future oil production of Canada, the Soviet Union, Venezuela and the world as a whole outside of the Middle East.

  7. Estimates on the minimal period for periodic solutions of nonlinear second order Hamiltonian systems

    International Nuclear Information System (INIS)

    Yiming Long.

    1994-11-01

    In this paper, we prove a sharper estimate on the minimal period for periodic solutions of autonomous second order Hamiltonian systems under precisely Rabinowitz' superquadratic condition. (author). 20 refs, 1 fig

  8. Bounded and Periodic Solutions of Semilinear Impulsive Periodic System on Banach Spaces

    Directory of Open Access Journals (Sweden)

    Wei W

    2008-01-01

    Full Text Available Abstract A class of semilinear impulsive periodic system on Banach spaces is considered. First, we introduce the -periodic PC-mild solution of semilinear impulsive periodic system. By virtue of Gronwall lemma with impulse, the estimate on the PC-mild solutions is derived. The continuity and compactness of the new constructed Poincaré operator determined by impulsive evolution operator corresponding to homogenous linear impulsive periodic system are shown. This allows us to apply Horn's fixed-point theorem to prove the existence of -periodic PC-mild solutions when PC-mild solutions are ultimate bounded. This extends the study on periodic solutions of periodic system without impulse to periodic system with impulse on general Banach spaces. At last, an example is given for demonstration.

  9. Seminar on the news energy utilization in rural area of April 3 to March 24 , 1980 in Reo, Upper Volta[Energie renouvelable ; Zone rurale ; Gaz biologique ; Energie solaire ; Sechoir solaire]; Seminaire sur l'utilisation des energies nouvelles en zone rurale du 24 mars au3 avril 1980 a Reo, Haute Volta

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1980-04-15

    volume of transport much more reduced. Mastering these new technologies will help fight efficiently against desertification, and fruits and vegetables rotting. [French] L'acces a l'energie par toutes les populations reste une des preoccupations du Gouvernement de Haute Volta (Burkina Faso). C'est ainsi que sous l'egide de la Communaute Economique de l Afrique de l'Ouest (CEAO), de l'Agence Canadienne de Developpement International et du Mouvement Scout, un seminaire sur l'utilisation des energies renouvelables en zone rurale y a ete organise. Il s'agit pour les participants venus de plusieurs pays, d'apprendre a mettre en pratique, l'utilisation des energies nouvelles telles la cuisiniere a feu ferme, le gaz biologique, le chauffe- eau solaire et le sechoir solaire. L'adoption de ces nouvelles sources d'energie par les populations permettrait de pallier les problemes de desertification lies au deboisement intensif dans le pays. Tous les participants a cette rencontre sont donc sensibilises pour qu'ils apportent leur contribution et celle des populations de leurs terroirs respectifs pour une meilleure conservation des ressources naturelles disponibles. Cela passe aussi par la construction de cuisinieres a feu ferme qui permettent d'avoir deux sources d'energie. Ce type de foyer est d'une construction facile et utilisable seulement trois jours apres. Il permet d'eviter la perte d'energie qui caracterisait le foyer traditionnel (pres de 95% de perte d'energie) ; ce qui revient a consommer moins de bois tout en assurant un rendement de l'ordre de 60 a 70%. Il s'est agi pour les participants aux travaux de s'initier a l'installation de gaz suivant des modeles chinois et indien . Ils ont donc ete inities a la realisation des technologies de production de gaz biologique a travers la maitrise du schema de principe du procede de fermentation discontinue. De meme, ils ont acquis le savoir- faire sur les techniques de mise en place du chauffe- eau solaire par insolateur et du

  10. Convergence acceleration of quasi-periodic and quasi-periodic-rational interpolations by polynomial corrections

    OpenAIRE

    Lusine Poghosyan

    2014-01-01

    The paper considers convergence acceleration of the quasi-periodic and the quasi-periodic-rational interpolations by application of polynomial corrections. We investigate convergence of the resultant quasi-periodic-polynomial and quasi-periodic-rational-polynomial interpolations and derive exact constants of the main terms of asymptotic errors in the regions away from the endpoints. Results of numerical experiments clarify behavior of the corresponding interpolations for moderate number of in...

  11. Periodic Table Target: A Game that Introduces the Biological Significance of Chemical Element Periodicity

    Science.gov (United States)

    Sevcik, Richard S.; McGinty, Ragan L.; Schultz, Linda D.; Alexander, Susan V.

    2008-01-01

    Periodic Table Target, a game for middle school or high school students, familiarizes students with the form of the periodic table and the biological significance of different elements. The Periodic Table Target game board is constructed as a class project, and the game is played to reinforce the content. Students are assigned several elements…

  12. Period, Place and Mental Space: Using Historical Scholarship to Develop Year 7 Pupils' Sense of Period

    Science.gov (United States)

    Smith, Dan

    2014-01-01

    What is a sense of period? And how can pupils' sense of period be developed? Questions such as these have troubled history teachers for many years, often revolving around debates over the role played by empathy and imagination in coming to know a period on its own terms. Rather than adopt a comparative approach, Dan Smiths decided in his teaching…

  13. Charged particle periodicity in the Saturnian magnetosphere

    International Nuclear Information System (INIS)

    Carbary, J.F.; Krimigis, S.M.

    1982-01-01

    The low energy charged particles (LECP) experiments on the Voyager 1 and 2 spacecraft performed measurements of electrons (approx.22 keV to approx.20 MeV) and ions (approx.28 keV to approx.150 MeV) during the Saturn encounters in 1980 and 1981. Count rate ratios of two of the low energy electron (22 to 35 keV and 183 to 500 keV) and ion (43 to 80 keV and 137 to 215 keV) channels exhibit an approximation 10 hour periodicity in the outer Saturnian magnetosphere beyond the orbit of Titan. Electron ratios vary from approx.50 to approx.300; ion ratios vary from approx.3 to approx.20. Similar but less pronounced periodicities are observed for higher and lower energy electron and ion spectral indices. Three complete cycles were observed during the Voyager 2 outbound portion of the encounter from which were determined an electron ratio period of 10/sup h/21/sup m/ +- 48/sup m/ and an ion ratio period of 9/sup h/49/sup m/ +- 59/sup m/. Using Saturn Kilometric Radiation (SKR) and Saturn Electrostatic Discharge (SED) periods, extrapolation backward from Voyager 2 to Voyager 1 suggests that the periodicities are Saturnian rather than Jovian in nature, and that they persist in phase for time intervals at least as long as 287 days. Ratio minima, or spectral hardenings, occur in the same hemisphere as do auroral brightenings, SKR activity, and spoke enhanement. We interpret the observations as prima facie evidence of an asymmetry in the Saturian magnetic field and the root cause of the observed SKR periodicity

  14. The period-age relation for cepheids

    International Nuclear Information System (INIS)

    Efremov, Yu.N.

    1978-01-01

    The list of 119 cepheid-members of 55 clusters and associations of the Magellanic Clouds, the Galaxy, and M31 is given. The period-age relation is found from the data on 64 cepheids in 29 clusters for which the age determinations are available, the ages of extragalactic clusters were determined mainly from their integral colours. The U-B colours are found to be of much better age parameters than the B-V ones. The composite period-age relation agrees well with the theoretical one. The observed dispersion of the period-age relation leads to an estimate of the age dispersion about 1x10 7 years in the associations. Some peculiarities of the cepheids with the shortest periods amongst others in the same clusters are probably explained if they are overtone pulsators. The period-age relation may be used for an investigation of the recent history of star formation in the galaxies. This relation allows to determine the age gradient across the spiral arm in M31 which is in agreement with the density wave theory predictions. The distribution of cepheids in our Galaxy and neighbouring galaxies is consistent with the conception of star formation lasting for some dozen million years in cells with a dimension of some hundreds of parsecs

  15. Periodic subsystem density-functional theory

    International Nuclear Information System (INIS)

    Genova, Alessandro; Pavanello, Michele; Ceresoli, Davide

    2014-01-01

    By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn–Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn–Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed

  16. Periodic subsystem density-functional theory

    Science.gov (United States)

    Genova, Alessandro; Ceresoli, Davide; Pavanello, Michele

    2014-11-01

    By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn-Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn-Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed.

  17. Multiphase averaging of periodic soliton equations

    International Nuclear Information System (INIS)

    Forest, M.G.

    1979-01-01

    The multiphase averaging of periodic soliton equations is considered. Particular attention is given to the periodic sine-Gordon and Korteweg-deVries (KdV) equations. The periodic sine-Gordon equation and its associated inverse spectral theory are analyzed, including a discussion of the spectral representations of exact, N-phase sine-Gordon solutions. The emphasis is on physical characteristics of the periodic waves, with a motivation from the well-known whole-line solitons. A canonical Hamiltonian approach for the modulational theory of N-phase waves is prescribed. A concrete illustration of this averaging method is provided with the periodic sine-Gordon equation; explicit averaging results are given only for the N = 1 case, laying a foundation for a more thorough treatment of the general N-phase problem. For the KdV equation, very general results are given for multiphase averaging of the N-phase waves. The single-phase results of Whitham are extended to general N phases, and more importantly, an invariant representation in terms of Abelian differentials on a Riemann surface is provided. Several consequences of this invariant representation are deduced, including strong evidence for the Hamiltonian structure of N-phase modulational equations

  18. Medicine in Balkans during the Roman Period.

    Science.gov (United States)

    Baykan, Daniş

    2017-08-04

    The aim of this study is to investigate the archaeological finds to enlighten the medical methods of treatments and operations applied in Balkans during Roman Period. Some independent local and regional find groups, taken from existing publications will be grouped together and a holistic point-of-view will be taken against medicine in Balkan Geography during Roman Period. Due to basic differences it contained, the data before Roman Period are excluded. Most of Greece and Aegean Islands are also excluded since the topic selected is "Medicine of Roman Period." Greece and Aegean Islands should be evaluated in another study in connection with West Anatolia which is closer than the Balkan Geography in terms of social relations. The spread of medical tools in Balkans during Roman Period is concentrated around military garrisons, and in settlements built around military pathways, and in settlements containing an amphitheater associated with gladiators. This spread is verified by the studies on Bulgaria in general. The data is also compatible with the assertion suggesting that the amount of application of pharmaceutical treatment increases when one moves away from the military centres.

  19. The Discrete Beverton-Holt Model with Periodic Harvesting in a Periodically Fluctuating Environment

    Directory of Open Access Journals (Sweden)

    Ziyad AlSharawi

    2010-01-01

    Full Text Available We investigate the effect of constant and periodic harvesting on the Beverton-Holt model in a periodically fluctuating environment. We show that in a periodically fluctuating environment, periodic harvesting gives a better maximum sustainable yield compared to constant harvesting. However, if one can also fix the environment, then constant harvesting in a constant environment can be a better option, especially for sufficiently large initial populations. Also, we investigate the combinatorial structure of the periodic sequence of carrying capacities and its effect on the maximum sustainable yield. Finally, we leave some questions worth further investigations.

  20. On complex periodic motions and bifurcations in a periodically forced, damped, hardening Duffing oscillator

    International Nuclear Information System (INIS)

    Guo, Yu; Luo, Albert C.J.

    2015-01-01

    In this paper, analytically predicted are complex periodic motions in the periodically forced, damped, hardening Duffing oscillator through discrete implicit maps of the corresponding differential equations. Bifurcation trees of periodic motions to chaos in such a hardening Duffing oscillator are obtained. The stability and bifurcation analysis of periodic motion in the bifurcation trees is carried out by eigenvalue analysis. The solutions of all discrete nodes of periodic motions are computed by the mapping structures of discrete implicit mapping. The frequency-amplitude characteristics of periodic motions are computed that are based on the discrete Fourier series. Thus, the bifurcation trees of periodic motions are also presented through frequency-amplitude curves. Finally, based on the analytical predictions, the initial conditions of periodic motions are selected, and numerical simulations of periodic motions are carried out for comparison of numerical and analytical predictions. The harmonic amplitude spectrums are also given for the approximate analytical expressions of periodic motions, which can also be used for comparison with experimental measurement. This study will give a better understanding of complex periodic motions in the hardening Duffing oscillator.

  1. Policy Uncertainty, Investment and Commitment Periods

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Today's investment decisions in key sectors such as energy, forestry or transport have significant impacts on the levels of greenhouse gas (GHG) emissions over the coming decades. Given the economic and environmental long-term implications of capital investment and retirement, a climate mitigation regime should aim to encourage capital investment in climate-friendly technologies. Many factors affect technology choice and the timing of investment, including investor expectations about future prices and policies. Recent international discussions have focused on the importance of providing more certainty about future climate policy stringency. The design of commitment periods can play a role in creating this environment. This paper assesses how the length of commitment periods influences policy uncertainty and investment decisions. In particular, the paper analyses the relationship between commitment period length and near term investment decisions in climate friendly technology.

  2. Magnetomechanically induced long period fiber gratings

    International Nuclear Information System (INIS)

    Causado-Buelvas, Jesus D.; Gomez-Cardona, Nelson D.; Torres, Pedro

    2008-01-01

    In this work, we report a simple, flexible method to create long period fiber gratings mechanically by controlling the repulsion/attraction force between two magnets that pressing a plate with a periodic array of small glass cylinders to a short length of optical fiber. Via the photoelastic effect, the pressure points induce the required periodic refractive index modulation to create the LPFG. We found that the induced device exhibits spectral characteristics similar to those of other types of LPFG. As the optical properties of LPFGs are directly related to the nature of the applied perturbations, we show, to our knowledge for the frrst time, how is the evolution of birefringence effects in mechanically induced LPFGs

  3. Effective propagation in a perturbed periodic structure

    Science.gov (United States)

    Maurel, Agnès; Pagneux, Vincent

    2008-08-01

    In a recent paper [D. Torrent, A. Hakansson, F. Cervera, and J. Sánchez-Dehesa, Phys. Rev. Lett. 96, 204302 (2006)] inspected the effective parameters of a cluster containing an ensemble of scatterers with a periodic or a weakly disordered arrangement. A small amount of disorder is shown to have a small influence on the characteristics of the acoustic wave propagation with respect to the periodic case. In this Brief Report, we inspect further the effect of a deviation in the scatterer distribution from the periodic distribution. The quasicrystalline approximation is shown to be an efficient tool to quantify this effect. An analytical formula for the effective wave number is obtained in one-dimensional acoustic medium and is compared with the Berryman result in the low-frequency limit. Direct numerical calculations show a good agreement with the analytical predictions.

  4. Effective propagation in a perturbed periodic structure

    International Nuclear Information System (INIS)

    Maurel, Agnes; Pagneux, Vincent

    2008-01-01

    In a recent paper [D. Torrent, A. Hakansson, F. Cervera, and J. Sanchez-Dehesa, Phys. Rev. Lett. 96, 204302 (2006)] inspected the effective parameters of a cluster containing an ensemble of scatterers with a periodic or a weakly disordered arrangement. A small amount of disorder is shown to have a small influence on the characteristics of the acoustic wave propagation with respect to the periodic case. In this Brief Report, we inspect further the effect of a deviation in the scatterer distribution from the periodic distribution. The quasicrystalline approximation is shown to be an efficient tool to quantify this effect. An analytical formula for the effective wave number is obtained in one-dimensional acoustic medium and is compared with the Berryman result in the low-frequency limit. Direct numerical calculations show a good agreement with the analytical predictions

  5. Krsko NPP Periodic Safety Review program

    International Nuclear Information System (INIS)

    Basic, I.; Spiler, J.; Novsak, M.

    2001-01-01

    The need for conducting a Periodic Safety Review for the Krsko NPP has been clearly recognized both by the NEK and the regulator (SNSA). The PSR would be highly desirable both in the light of current trends in safety oversight practices and because of many benefits it is capable to provide. On January 11, 2001 the SNSA issued a decision requesting the Krsko NPP to prepare a program and determine a schedule for the implementation of the program for 'Periodic Safety Review of NPP Krsko'. The program, which is required to be in accordance with the IAEA safety philosophy and with the EU practice, was submitted for the approval to the SNSA by the end of March 2001. The paper summarizes Krsko NPP Periodic Safety Review Program [1] including implemented SNSA and IAEA Expert Mission comments.(author)

  6. Electromagnetic Radiation of Electrons in Periodic Structures

    CERN Document Server

    Potylitsyn, Alexander Petrovich

    2011-01-01

    Periodic magnetic structures (undulators) are widely used in accelerators to generate monochromatic undulator radiation (UR) in the range from far infrared to the hard X-ray region. Another periodic crystalline structure is used to produce quasimonochromatic polarized photon beams via the coherent bremsstrahlung mechanism (CBS). Due to such characteristics as monochromaticity, polarization and adjustability, these types of radiation is of large interest for applied and basic research of accelerator-emitted radiation. The book provides a detailed overview of the fundamental principles behind electromagnetic radiation emitted from accelerated charged particles (e.g. UR, CBS, radiation of fast electrons in Laser flash fields) as well as a unified description of relatively new radiation mechanisms which attracted great interest in recent years. This are the so-called polarization radiation excited by the Coulomb field of incident particles in periodic structures, parametric X-rays, resonant transition radiation a...

  7. Subdomain Precise Integration Method for Periodic Structures

    Directory of Open Access Journals (Sweden)

    F. Wu

    2014-01-01

    Full Text Available A subdomain precise integration method is developed for the dynamical responses of periodic structures comprising many identical structural cells. The proposed method is based on the precise integration method, the subdomain scheme, and the repeatability of the periodic structures. In the proposed method, each structural cell is seen as a super element that is solved using the precise integration method, considering the repeatability of the structural cells. The computational efforts and the memory size of the proposed method are reduced, while high computational accuracy is achieved. Therefore, the proposed method is particularly suitable to solve the dynamical responses of periodic structures. Two numerical examples are presented to demonstrate the accuracy and efficiency of the proposed method through comparison with the Newmark and Runge-Kutta methods.

  8. [Hypertension and pregnancy: Post-partum period].

    Science.gov (United States)

    Hugon-Rodin, Justine; Plu-Bureau, Geneviève

    2016-01-01

    Post-partum period is associated with specific characteristics in women with gestational disorders or preeclampsia. For breastfeeding women, the choice of antihypertensive treatment should take into account the impact on child health. The impact of breastfeeding on health mother must be also discussed. Moreover, for lactation inhibition, bromocriptine should not be used, especially in the context of gestational disorders. In post-partum period, the best contraceptive strategy is only-progestin contraception or non-hormonal contraceptives use. However, this choice will depend on the stabilization or normalization of blood pressure in early post-partum period. Finally, several consultations should be suggested: an information and announcement to explain the consequences of these gestational disorders and organize their multidisciplinary management and follow-up. A preconceptional consultation takes its place to anticipate potential recurrent preeclampsia or gestational hypertension and to schedule a future pregnancy in optimal conditions. Copyright © 2016. Published by Elsevier Masson SAS.

  9. Quasi-periodicity in deep redshift surveys

    International Nuclear Information System (INIS)

    Weygaert, R. van de

    1991-01-01

    The recent result by Broadhurst et al., (1990. Nature 343, 726) showing a striking, nearly periodic, galaxy redshift distribution in a narrow pencil-beam survey, is explained within the Voronoi cellular model of clustering of galaxies. Galaxies, whose luminosities are selected from a Schechter luminosity function, are placed randomly within the walls of this cellular model. Narrow and deep, magnitude-limited, pencil-beam surveys through these structures are simulated. Some 15 per cent of these beams show that observed regular pattern, with a spacing between the peaks of the order of 105 h -1 -150 h -1 Mpc, but most pencil-beams show peaks in the redshift distribution without periodicity, so we may conclude that, even within a cellular universe, periodicity is not a common phenomenon. (author)

  10. Vlasov dynamics of periodically driven systems

    Science.gov (United States)

    Banerjee, Soumyadip; Shah, Kushal

    2018-04-01

    Analytical solutions of the Vlasov equation for periodically driven systems are of importance in several areas of plasma physics and dynamical systems and are usually approximated using ponderomotive theory. In this paper, we derive the plasma distribution function predicted by ponderomotive theory using Hamiltonian averaging theory and compare it with solutions obtained by the method of characteristics. Our results show that though ponderomotive theory is relatively much easier to use, its predictions are very restrictive and are likely to be very different from the actual distribution function of the system. We also analyse all possible initial conditions which lead to periodic solutions of the Vlasov equation for periodically driven systems and conjecture that the irreducible polynomial corresponding to the initial condition must only have squares of the spatial and momentum coordinate. The resulting distribution function for other initial conditions is aperiodic and can lead to complex relaxation processes within the plasma.

  11. Periodic safety analyses; Les essais periodiques

    Energy Technology Data Exchange (ETDEWEB)

    Gouffon, A; Zermizoglou, R

    1990-12-01

    The IAEA Safety Guide 50-SG-S8 devoted to 'Safety Aspects of Foundations of Nuclear Power Plants' indicates that operator of a NPP should establish a program for inspection of safe operation during construction, start-up and service life of the plant for obtaining data needed for estimating the life time of structures and components. At the same time the program should ensure that the safety margins are appropriate. Periodic safety analysis are an important part of the safety inspection program. Periodic safety reports is a method for testing the whole system or a part of the safety system following the precise criteria. Periodic safety analyses are not meant for qualification of the plant components. Separate analyses are devoted to: start-up, qualification of components and materials, and aging. All these analyses are described in this presentation. The last chapter describes the experience obtained for PWR-900 and PWR-1300 units from 1986-1989.

  12. Periodic solutions of Volterra integral equations

    Directory of Open Access Journals (Sweden)

    M. N. Islam

    1988-01-01

    Full Text Available Consider the system of equationsx(t=f(t+∫−∞tk(t,sx(sds,           (1andx(t=f(t+∫−∞tk(t,sg(s,x(sds.       (2Existence of continuous periodic solutions of (1 is shown using the resolvent function of the kernel k. Some important properties of the resolvent function including its uniqueness are obtained in the process. In obtaining periodic solutions of (1 it is necessary that the resolvent of k is integrable in some sense. For a scalar convolution kernel k some explicit conditions are derived to determine whether or not the resolvent of k is integrable. Finally, the existence and uniqueness of continuous periodic solutions of (1 and (2 are btained using the contraction mapping principle as the basic tool.

  13. Impact of the infectious period on epidemics

    Science.gov (United States)

    Wilkinson, Robert R.; Sharkey, Kieran J.

    2018-05-01

    The duration of the infectious period is a crucial determinant of the ability of an infectious disease to spread. We consider an epidemic model that is network based and non-Markovian, containing classic Kermack-McKendrick, pairwise, message passing, and spatial models as special cases. For this model, we prove a monotonic relationship between the variability of the infectious period (with fixed mean) and the probability that the infection will reach any given subset of the population by any given time. For certain families of distributions, this result implies that epidemic severity is decreasing with respect to the variance of the infectious period. The striking importance of this relationship is demonstrated numerically. We then prove, with a fixed basic reproductive ratio (R0), a monotonic relationship between the variability of the posterior transmission probability (which is a function of the infectious period) and the probability that the infection will reach any given subset of the population by any given time. Thus again, even when R0 is fixed, variability of the infectious period tends to dampen the epidemic. Numerical results illustrate this but indicate the relationship is weaker. We then show how our results apply to message passing, pairwise, and Kermack-McKendrick epidemic models, even when they are not exactly consistent with the stochastic dynamics. For Poissonian contact processes, and arbitrarily distributed infectious periods, we demonstrate how systems of delay differential equations and ordinary differential equations can provide upper and lower bounds, respectively, for the probability that any given individual has been infected by any given time.

  14. El pacto periodístico

    OpenAIRE

    Ma. de Lourdes Romero Álvarez

    2002-01-01

    En este artículo se plantea una de las cuestiones fundamentales sobre las que se realiza la actividad periodística y que la autora ha llamado el pacto periodístico. El pacto, celebrado entre el periodista y sus lectores, consiste en que el emisor expresa lo que sucedió tal y como lo vio y el destinatario acepta lo expresado en las mismas condiciones. El compromiso entre ambos participantes los obliga a saber y cumplir con lo estipulado en el contrato, para evitar que alguna de ...

  15. Pulsation properties of Mira long period variables

    International Nuclear Information System (INIS)

    Cahn, J.H.

    1980-01-01

    A matter of great interest to variable star students concerns the mode of pulsation of Mira long period variables. In this report we first give observational evidence for the pulsation constant Q. We then compare the observations with calculations. Next, we review two interesting groups of papers dealing with hydrodynamic properties of long period variables. In the first, a fully dynamic nonlinear calculation maps out the Mira instability domain. In the second, special attention is paid to shock propagation beyond the photosphere which in large measure accounts for the complex spectra from this region. (orig./WL)

  16. Short period tidal variations of earth rotation

    Science.gov (United States)

    Yoder, C. F.; Williams, J. G.; Parke, M. E.; Dickey, J. O.

    1981-01-01

    It is explained that the tidal deformation of the earth's polar moment of inertia by the moon and sun cause periodic variations in rotation. The short period oscillations give rise to a meter-sized, diurnal signature in the lunar laser ranging data obtained at McDonald Observatory. A solution is given for the scale parameter k/C at fortnightly and monthly tidal frequencies. The results are compared with those obtained by other investigators and with a theoretical estimate which includes the effect of oceans and a decoupled fluid core.

  17. Mathematics of Periodic Tables for Benzenoid Hydrocarbons.

    Science.gov (United States)

    Dias, Jerry Ray

    2007-01-01

    The upper and lower bounds for invariants of polyhex systems based on the Harary and Harborth inequalities are studied. It is shown that these invariants are uniquely correlated by the Periodic Table for Benzenoid Hydrocarbons. A modified periodic table for total resonant sextet (TRS) benzenoids based on the invariants of Ds and r(empty) is presented; Ds is the number of disconnections among the empty rings for fused TRS benzenoid hydrocarbons. This work represents a contribution toward deciphering the topological information content of benzenoid formulas.

  18. Orbital Period Changes in WZ Sagittae

    Science.gov (United States)

    Patterson, Joseph; Stone, Geoffrey; Kemp, Jonathan; Skillman, David R.; de Miguel, Enrique; Potter, Michael; Starkey, Donn; Uthas, Helena; Jones, Jim; Slauson, Douglas; Koff, Robert; Myers, Gordon; Menzies, Kenneth; Campbell, Tut; Roberts, George; Foote, Jerry; Vanmunster, Tonny; Cook, Lewis M.; Krajci, Thomas; Ogmen, Yenal; Sabo, Richard; Seargeant, Jim

    2018-06-01

    We report a long-term (1961–2017) study of the eclipse times in the dwarf nova WZ Sagittae, in an effort to learn its rate of orbital-period change. Some wiggles with a timescale of 20–50 years are apparent, and a connection with the ∼23 year interval between dwarf-nova eruptions is possible. These back-and-forth wiggles dominate the O–C diagram, and prevent a secure measurement of the steady rate of orbital-period change.

  19. Radiocarbon clock strikes the glacial period pulse

    International Nuclear Information System (INIS)

    Serebryannyj, L.R.

    1976-01-01

    Discussed are some aspects of the theory of radiocarbon dating in application to the study of the history of the Earth. The accumulation and the decay of C 14 and methods for its recording are desribed. Presented is a block diagram of a scintillation counter for recording C 14 . The chronology of the last glaciation of Europe has been determined: the Interglacial period (between 50 and 40 thousand years) a prolonged preglacil period (between 40 and 25 thousand years), the last glaciation (between 25 and 10 thousand years ago)

  20. [Hypoglycaemic periodic paralysis in hyperthyroidism patients].

    Science.gov (United States)

    Kratochvíl, J; Masopust, J; Martínková, V; Charvát, J

    2008-11-01

    Hypokalemic periodic paralysis (HPP) is a rare disorder characterised by acute, potentially fatal atacks of muscle weakness or paralysis. Massive shift of potassium into cells is caused by elevated levels of insulin and catecholamines in the blood. Hypophosphatemia and hypomagnesemia may be also present. Acidobasic status usually is not impaired. HPP occurs as familiar (caused by ion channels inherited defects) or acquired (in patients with hyperthyroidism). On the basis of two clinical cases we present a review of hypokalemic periodic paralysis in hyperthyroid patients. We discuss patogenesis, clinical and laboratory findings as well as the principles of prevention and treatment of this rare disorder.

  1. Using periodicity to mitigate ground vibration

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard

    2015-01-01

    Introduction of trenches, barriers and wave impeding blocks on the transmission path between a source and receiver can be used for mitigation of ground vibration. However, to be effective a barrier must have a depth of about one wavelength of the waves to be mitigated. Hence, while great reductions......: A soil with periodic stiffening (ground improvement) and a ground with periodic changes in the surface elevation obtained by artificial landscaping. By means of a two-dimensional finite-element model, the stiffness and mass matrices are determined for a single cell of the ground with horizonal...

  2. Reconstruction of periodic signals using neural networks

    Directory of Open Access Journals (Sweden)

    José Danilo Rairán Antolines

    2014-01-01

    Full Text Available In this paper, we reconstruct a periodic signal by using two neural networks. The first network is trained to approximate the period of a signal, and the second network estimates the corresponding coefficients of the signal's Fourier expansion. The reconstruction strategy consists in minimizing the mean-square error via backpro-pagation algorithms over a single neuron with a sine transfer function. Additionally, this paper presents mathematical proof about the quality of the approximation as well as a first modification of the algorithm, which requires less data to reach the same estimation; thus making the algorithm suitable for real-time implementations.

  3. Periodic Boundary Motion in Thermal Turbulence

    International Nuclear Information System (INIS)

    Zhang, Jun; Libchaber, Albert

    2000-01-01

    A free-floating plate is introduced in a Benard convection cell with an open surface. It partially covers the cell and distorts the local heat flux, inducing a coherent flow that in turn moves the plate. Remarkably, the plate can be driven to a periodic motion even under the action of a turbulent fluid. The period of the oscillation depends on the coverage ratio, and on the Rayleigh number of the convective system. The plate oscillatory behavior observed in this experiment may be related to a geological model, in which continents drift in a quasiperiodic fashion. (c) 2000 The American Physical Society

  4. On Helmholtz Problem for Plane Periodical Structures

    International Nuclear Information System (INIS)

    Akishin, P.G.; Vinitskij, S.I.

    1994-01-01

    The plane Helmholtz problem of the periodical disc structures with the phase shifts conditions of the solutions along the basis lattice vectors and the Dirichlet conditions on the basic boundaries is considered. The Green function satisfying the quasi periodical conditions on the lattice is constructed. The Helmholtz problem is reduced to the boundary integral equations for the simple layer potentials of this Green function. The methods of the discretization of the arising integral equations are proposed. The procedures of calculation of the matrix elements are discussed. The reality of the spectral parameter of the nonlinear continuous and discretized problems is shown. 8 refs., 2 figs

  5. Culture and Cooperation during the Interwar Period

    Directory of Open Access Journals (Sweden)

    Anişoara Popa

    2015-05-01

    Full Text Available Starting from the most important Publications of the International Institute for Intellectual Cooperation (1925-1946 we will explore the ideas concerning culture and personalities involved in the intellectual cooperation during the Interwar Period. Pointing out the role that the International Institute of Intellectual Cooperation had and the Romanian contribution to this cooperation is another purpose of this article.

  6. Periodic Solutions for Highly Nonlinear Oscillation Systems

    DEFF Research Database (Denmark)

    Ghadimi, M; Barari, Amin; Kaliji, H.D

    2012-01-01

    In this paper, Frequency-Amplitude Formulation is used to analyze the periodic behavior of tapered beam as well as two complex nonlinear systems. Many engineering structures, such as offshore foundations, oil platform supports, tower structures and moving arms, are modeled as tapered beams...

  7. Periodic review in natural resource contracts | Mandelbaum ...

    African Journals Online (AJOL)

    Periodic contract review mechanisms, which are provisions in contracts that formally require parties to meet at particular intervals to review the terms of the contract, are mechanisms that may facilitate the process of negotiating contractual changes to accommodate changing circumstances over the term of extractive ...

  8. Resonances in a periodically driven bosonic system

    Science.gov (United States)

    Quelle, Anton; Smith, Cristiane Morais

    2017-11-01

    Periodically driven systems are a common topic in modern physics. In optical lattices specifically, driving is at the origin of many interesting phenomena. However, energy is not conserved in driven systems, and under periodic driving, heating of a system is a real concern. In an effort to better understand this phenomenon, the heating of single-band systems has been studied, with a focus on disorder- and interaction-induced effects, such as many-body localization. Nevertheless, driven systems occur in a much wider context than this, leaving room for further research. Here, we fill this gap by studying a noninteracting model, characterized by discrete, periodically spaced energy levels that are unbounded from above. We couple these energy levels resonantly through a periodic drive, and discuss the heating dynamics of this system as a function of the driving protocol. In this way, we show that a combination of stimulated emission and absorption causes the presence of resonant stable states. This will serve to elucidate the conditions under which resonant driving causes heating in quantum systems.

  9. 5 CFR 317.503 - Probationary period.

    Science.gov (United States)

    2010-01-01

    .... (b) When a career appointee's executive qualification have been certified by a Qualifications Review... THE SENIOR EXECUTIVE SERVICE Career Appointments § 317.503 Probationary period. (a) An individual's initial appointment as an SES career appointee becomes final only after the individual has served a 1-year...

  10. New Realization of Periodic Cycled Separation

    DEFF Research Database (Denmark)

    Toftegard, Bjarne; Clausen, Charlotte H.; Jørgensen, Sten B.

    2016-01-01

    are drained sequentially rather than simultaneously, such that the vapor flow is not interrupted during the liquid drainage. For different ratios of counter-current vapor/liquid flow rates, column efficiencies for periodically cycled columns are shown experimentally to be two times greater than those...

  11. Teaching the Hitler Period: History and Morality.

    Science.gov (United States)

    Mork, Gordon R.

    1980-01-01

    Outlines six approaches used in a university history course which address the problems of teaching the Hitler period. The assumption underlying all the approaches is that Americans are not entirely different from Germans and that they may be faced with similar moral choices. The approaches avoid the didactic moralism often taught about this era.…

  12. Vitamins and administration periods effects on haematological ...

    African Journals Online (AJOL)

    Vitamins and administration periods effects on haematological parameters of broiler ... Data obtained on haematological indices were subjected to Analysis of ... été répartis sur base de l'égalisation du poids en neuf (9) groupes de traitement, ...

  13. Regular arrangement of periodates bound to lysozyme

    Czech Academy of Sciences Publication Activity Database

    Ondráček, Jan; Weiss, M.S.; Brynda, Jiří; Fiala, J.; Jursík, F.; Řezáčová, Pavlína; Jenner, L.B.; Sedláček, Juraj

    2005-01-01

    Roč. 61, Pt9 (2005), s. 1181-1189 ISSN 0907-4449 Institutional research plan: CEZ:AV0Z50520514 Keywords : hen egg white lysozyme * periodate * epitaxy Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.401, year: 2005

  14. QS Spiral: Visualizing Periodic Quantified Self Data

    DEFF Research Database (Denmark)

    Larsen, Jakob Eg; Cuttone, Andrea; Jørgensen, Sune Lehmann

    2013-01-01

    In this paper we propose an interactive visualization technique QS Spiral that aims to capture the periodic properties of quantified self data and let the user explore those recurring patterns. The approach is based on time-series data visualized as a spiral structure. The interactivity includes ...

  15. Gestation period and twinning in chimpanzees.

    Science.gov (United States)

    PEACOCK, L J; ROGERS, C M

    1959-04-10

    The length of the gestation period in 118 births in a colony of chimpanzees was found to be 226.8 days, with a standard deviation of 13.3 and a range of 196 to 260 days. Six pairs of twins were born in 120 parturitions; thus the apparent twinning rate is higher than that in man.

  16. Theory of periodic conjugate heat transfer

    CERN Document Server

    Zudin, Yuri B

    2016-01-01

    This book presents the theory of periodic conjugate heat transfer in detail. It offers a simplified description of the interaction between a solid body and a fluid as a boundary value problem of the heat conduction equation for the solid body.

  17. Periodic diffeomorphisms on homotopy E (4) surfaces

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 124; Issue 3. Periodic Diffeomorphisms on Homotopy (4) Surfaces. Hongxia Li. Volume 124 Issue 3 August 2014 pp 437-445. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/pmsc/124/03/0437-0445 ...

  18. Pleural effusions in the postpartum period

    International Nuclear Information System (INIS)

    Stark, P.; Pollack, M.S.

    1986-01-01

    We report on the high frequency of pleural effusions in the immediate postpartum period. Forty-four out of 45 women who examined within 24-48 h after delivery showed evidence of pleural fluid. Under these circumstances, this pleural abnormality should not be considered an indicator of serious cardiopulmonary disease. (orig.) [de

  19. U. S. and Canadian Indian Periodicals.

    Science.gov (United States)

    Price, John

    The document lists and discusses Indian-published and Indian-oriented newspapers, periodicals, and other assorted publications generally designed to establish a communication system reflecting the interest of the majority of American Indians. Also provided are resumes of several publications that are thought to have gained wide acceptance through…

  20. Periodical Cicada--Brood V (Pest Alert)

    Science.gov (United States)

    USDA Forest Service

    1999-01-01

    Three separate species of periodical cicadas, Magicicada septendecim (L.), M. cassini (Fisher), and M. septendecula (Alexander and Moore), will appear this spring over large portions of Ohio and West Virginia during the scheduled Brood V emergence. This brood is the largest that occurs in either state and was last seen in 1982. It will also emerge in the southwest...

  1. Engineered quantum tunnelling in extended periodic potentials

    Energy Technology Data Exchange (ETDEWEB)

    Wimberger, Sandro; Ciampini, Donatella; Morsch, Oliver; Mannella, Riccardo; Arimondo, Ennio [CNR-INFM and Dipartimento di Fisica ' Enrico Fermi' , Largo Pontecorvo 3, 1-56127 Pisa (Italy)

    2007-05-15

    Quantum tunnelling from a tilted, but otherwise periodic potential is studied. Our theoretical and experimental results show that, by controlling the system's parameters, we can engineer the escape rate of a Bose-Einstein condensate to an exceptional degree. Possible applications of this atom-optics realization of the open Wannier-Stark system are discussed.

  2. Periodic and recurrent variations of cosmic rays

    International Nuclear Information System (INIS)

    Somogyi, A.J.

    1981-12-01

    The new results achieved in the field of periodic and recurrent variations of the intensity of 10 9 to 10 13 eV cosmic rays are reviewed. Particular emphasis is given to developments in understanding the fluctuations of corotation-type anisotropies as well as to the structure of the heliosphere and its temporal changes. (author)

  3. 42 CFR 423.38 - Enrollment periods.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Enrollment periods. 423.38 Section 423.38 Public... material provision of its contract under this part in relation to the individual, including, but not... in marketing the plan to the individual. (ii) The individual meets other exceptional circumstances as...

  4. NPP Krsko Periodic Safety Review action plan

    International Nuclear Information System (INIS)

    Bilic Zabric, T.

    2006-01-01

    In the current, internationally accepted, safety philosophy Periodic Safety Reviews (PSRs) are comprehensive reviews aimed at the verification that an operating NPP remains safe when judged against current safety objectives and practices and that adequate arrangements are in place to maintain an acceptable level of safety. These reviews are complementary to the routine and special safety reviews. They are long time-scale reviews intended to deal with the cumulative effects of plant ageing, modifications, operating experience and technical developments, which are not so easily comprehended over the shorter time-scale routine of safety reviews. The review was completed in 2005 and the next period will see the implementation of the action plan including some plant upgrades. The action plan lists issues that should be implemented at NPP Krsko together with associated milestones. The milestones were assumed based on best estimate resource availability and their ends can be potentially floated. In some cases, multiple corrective measures may be postulated to provide resolution for a given safety issue. The Slovenian Nuclear Safety Administration by decree approved the first periodic safety review and the implementation plan of activities arising from it. The entire implementation plan must be carried out by 15 October 2010. Report on the second periodic safety review must be submitted by the NEK not later than 15 December 2013. (author)

  5. Ultrasound periodic inspections of reactor pressure vessels

    International Nuclear Information System (INIS)

    Haniger, L.

    1980-01-01

    Two versions are described of ultrasonic equipment for periodic inspections of reactor pressure vessels. One uses the principle of exchangeable programmators with solid-state logic while the other uses programmable logic with semiconductor memories. The equipment is to be used for inspections of welded joints on the upper part of the V-1 reactor pressure vessel. (L.O.)

  6. 5 CFR 2634.908 - Reporting periods.

    Science.gov (United States)

    2010-01-01

    ... DISCLOSURE, QUALIFIED TRUSTS, AND CERTIFICATES OF DIVESTITURE Confidential Financial Disclosure Reports § 2634.908 Reporting periods. (a) Incumbents. Each confidential financial disclosure report filed under... information required to be reported according to the provisions of this subpart for the preceding calendar...

  7. Periodic and in-service inspection programs

    International Nuclear Information System (INIS)

    Dinu, M.

    2000-01-01

    Periodic and in-service inspection programs for Cernavoda NPP consists of periodic inspections of CANDU NPP components CSAN N-285.4 and CSAN N-285.4, in-service inspections and repair and modifications general inspection. Periodic inspection program document (PIPD) determines the systems and components subject to inspection, the category of the inspection, techniques, areas and other details.The current status of the inspection programs is presented, including containment , erosion/corrosion, pressure vessel support and snubbers, main steam lines inspection programs. Qualification program in Cernavoda NPP involves equipment qualification in the on-site laboratory, yearly certification, special equipment qualification in the National Institute of Metrology. All procedures are approved by the ISCIR (regulatory body for pressure vessel and lifting equipment) and CNCAN (National Commission on Nuclear Activities Control). Qualification of the personnel is performed according to the ISCIR Technical prescription CR 11/82 for up to 3 year period. Final qualification and licensing is performed by CNCAN

  8. Anomalous periodic disruptions in tokamak plasma

    International Nuclear Information System (INIS)

    Montvai, A.; Tegze, M.; Valyi, I.

    1982-09-01

    Anomalously strong, periodic instabilities were observed in the MT-1 tokamak. Characteristics of these instabilities were partly similar to those of internal disruptions, but there were features making them different from the normal relaxational oscillations. Basic characteristics of the phenomenon were studied with the aid of generally used diagnostics. (author)

  9. 14 CFR 271.8 - Rate period.

    Science.gov (United States)

    2010-01-01

    ... Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS GUIDELINES FOR SUBSIDIZING AIR CARRIERS PROVIDING ESSENTIAL AIR TRANSPORTATION § 271.8 Rate period... place essential air service level; or (5) The uncertainties of the market or other circumstances warrant...

  10. Periodic Solutions for Circular Restricted -Body Problems

    Directory of Open Access Journals (Sweden)

    Xiaoxiao Zhao

    2013-01-01

    Full Text Available For circular restricted -body problems, we study the motion of a sufficiently small mass point (called the zero mass point in the plane of equal masses located at the vertices of a regular polygon. By using variational minimizing methods, for some , we prove the existence of the noncollision periodic solution for the zero mass point with some fixed wingding number.

  11. Mental Illness in the Peripartum Period

    Science.gov (United States)

    Ostler, Teresa

    2009-01-01

    Women are particularly vulnerable in the peripartum period for either developing a mental illness or suffering symptom exacerbation. These illnesses are often experienced covertly, however, and women may not seek out professional help, even though their symptoms may be seriously affecting their well-being and parenting. This article provides an…

  12. Isomeric periodic mesoporous organosilicas with controllable properties

    NARCIS (Netherlands)

    Vercaemst, C.; Ide, I.; Friedrich, H.; de Jong, K.P.; Verpoort, F.; van der Voort, P.

    2009-01-01

    The synthesis procedure for isomeric periodic mesoporous organosilicas with E-configured ethenylene bridges was investigated using the homemade pure E-isomer of 1,2-bis(triethoxysilyl)ethene. The pH, aging temperature and the presence of cosolvents played a key role in obtaining well-ordered

  13. The Different Periodic Tables of Dmitrii Mendeleev

    Science.gov (United States)

    Laing, Michael

    2008-01-01

    Between 1869 and 1905 the Russian chemist Dmitrii Mendeleev published several tables with different arrangements of the chemical elements. Four of these are compared with periodic tables by Russian scientists from 1934 and 1969. The difficulties caused by the lanthanoid elements are clearly seen in the table of 1905, which satisfactorily includes…

  14. Ecological periodic tables for estuarine habitats

    Science.gov (United States)

    Southwood (1977; J Anim Ecol 46: 337-365) compared the situation in ecology to that in chemistry before the development of the periodic table when each fact, for example, the solubility or reactivity of a chemical element, had to be discovered independently and remembered in isol...

  15. Relating Functional Groups to the Periodic Table

    Science.gov (United States)

    Struyf, Jef

    2009-01-01

    An introduction to organic chemistry functional groups and their ionic variants is presented. Functional groups are ordered by the position of their specific (hetero) atom in the periodic table. Lewis structures are compared with their corresponding condensed formulas. (Contains 5 tables.)

  16. Decision Making during the Psychological Refractory Period

    NARCIS (Netherlands)

    Zylberberg, Ariel; Ouellette, Brian; Sigman, Mariano; Roelfsema, Pieter R.

    2012-01-01

    In spite of its massively parallel architecture [1], the human brain is fundamentally limited if required to perform two tasks at the same time [2, 3]. This limitation can be studied with the psychological refractory period (PRP) paradigm, where two stimuli that require speeded responses occur in

  17. Resonances in a periodically driven bosonic system.

    Science.gov (United States)

    Quelle, Anton; Smith, Cristiane Morais

    2017-11-01

    Periodically driven systems are a common topic in modern physics. In optical lattices specifically, driving is at the origin of many interesting phenomena. However, energy is not conserved in driven systems, and under periodic driving, heating of a system is a real concern. In an effort to better understand this phenomenon, the heating of single-band systems has been studied, with a focus on disorder- and interaction-induced effects, such as many-body localization. Nevertheless, driven systems occur in a much wider context than this, leaving room for further research. Here, we fill this gap by studying a noninteracting model, characterized by discrete, periodically spaced energy levels that are unbounded from above. We couple these energy levels resonantly through a periodic drive, and discuss the heating dynamics of this system as a function of the driving protocol. In this way, we show that a combination of stimulated emission and absorption causes the presence of resonant stable states. This will serve to elucidate the conditions under which resonant driving causes heating in quantum systems.

  18. Polarization of a periodic solar microwave burst

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, P [Universidade Mackenzie, Sao Paulo (Brazil). Centro de Radio-Astronomia e Astrofisica

    1976-09-01

    No fluctuations in polarization have been found during a 7 GHz solar burst showing 17s periodic pulses in intensity. Polarization effects can be produced by the propagation media in the active centre, which are not affected directly by the burst source, but situated more deeply than the observed heights at that microwave frequency.

  19. Audibility of harmonics in periodic "white noise"

    NARCIS (Netherlands)

    Duifhuis, H.

    1973-01-01

    The finding that spectrally suppressed high harmonics (n>16) in a periodic pulse are perceptible has been related [H. Duifhuis, J. Acoust. Soc. Amer. 48, 888–893 (1970); 49, 1155–1163 (1971)] to the ear's limited resolving power in peripheral frequency analysis. The limited frequency resolution

  20. Audibility of harmonics in 'periodic white noise'

    NARCIS (Netherlands)

    Duifhuis, H.; Tomesen, H.H.

    1970-01-01

    In a previous article (Duifhuis, 1970) results' concerning the audibility of harmonics in a periodic pulse have been presented. Each of the lower harmonics could be perceived separately, whereas the high harmonics were heard together as one complex signal. High harmonics, however, appeared to be