WorldWideScience

Sample records for natural transmission cycles

  1. Multinational Firms and Business Cycle Transmission

    DEFF Research Database (Denmark)

    Menno, Dominik Francesco

    This paper studies the effect of foreign direct investment (FDI) on the transmission of international business cycles. I document for the G7 countries between 1991 and 2006 that increases in bilateral FDI linkages are associated with more synchronized investment cycles. I also find...... that the relation between FDI integration and synchronization of gross domestic product (GDP) is - yet positive - statistically insignificant after controlling for time fixed effects. I then study a model of international business cycles with an essential role for FDI and shocks to multinational activity...

  2. Natural Leishmania (Viannia) spp. infections in phlebotomine sand flies (Diptera: Psychodidae) from the Brazilian Amazon region reveal new putative transmission cycles of American cutaneous leishmaniasis

    Science.gov (United States)

    de Souza, Adelson Alcimar Almeida; dos Santos, Thiago Vasconcelos; Jennings, Yara Lúcia Lins; Ishikawa, Edna Aoba Yassui; Barata, Iorlando da Rocha; Silva, Maria das Graças Soares; Lima, José Aprígio Nunes; Shaw, Jeffrey; Lainson, Ralph; Silveira, Fernando Tobias

    2016-01-01

    In Amazonian Brazil the etiological agents of American cutaneous leishmaniasis (ACL) belong to at least seven Leishmania species but little is known about the putative phlebotomine sand fly vectors in different biomes. In 2002–2003 a survey of the phlebotomine fauna was undertaken in the “Floresta Nacional do Tapajós”, Belterra municipality, in the lower Amazon region, western Pará State, Brazil, where we recently confirmed the presence of a putative hybrid parasite, L. (V.) guyanensis × L. (V.) shawi shawi. Sand flies were collected from Centers for Disease Control (CDC) light traps, Shannon traps and by aspiration on tree bases. Females were dissected and attempts to isolate any flagellate infections were made by inoculating homogenized midguts into Difco B45 medium. Isolates were characterized by monoclonal antibodies and isoenzyme electrophoresis. A total of 9,704 sand flies, belonging to 68 species or subspecies, were collected. Infections were found in the following sand flies: L. (V.) naiffi with Psychodopygus hirsutus hirsutus (1) and Ps. davisi (2); and L. (V.) shawi shawi with Nyssomyia whitmani (3) and Lutzomyia gomezi (1). These results provide strong evidence of new putative transmission cycles for L. (V.) naiffi and L. (V.) s. shawi. PMID:27235194

  3. Natural Leishmania (Viannia) infections of phlebotomines (Diptera: Psychodidae) indicate classical and alternative transmission cycles of American cutaneous leishmaniasis in the Guiana Shield, Brazil.

    Science.gov (United States)

    de Souza, Adelson Alcimar Almeida; da Rocha Barata, Iorlando; das Graças Soares Silva, Maria; Lima, José Aprígio Nunes; Jennings, Yara Lúcia Lins; Ishikawa, Edna Aoba Yassui; Prévot, Ghislaine; Ginouves, Marine; Silveira, Fernando Tobias; Shaw, Jeffrey; Dos Santos, Thiago Vasconcelos

    2017-01-01

    From 1996 to 1999 multi-trapping methods (Center of Diseases Control, CDC) light traps, light-baited Shannon traps, and aspiration on tree bases) were used to study the phlebotomine fauna of the "Serra do Navio" region of the Brazilian State of Amapá, which is part of the Guiana Shield. Fifty-three species were identified among 8,685 captured individuals. The following species, associated with the transmission of American cutaneous leishmaniasis in Amazonian Brazil, were captured: Nyssomyia umbratilis (3,388), Psychodopygus squamiventris maripaensis (995), Ny. anduzei (550), Trichophoromyia ubiquitalis (400), Ny. whitmani (291), Ps. paraensis (116), and Bichromomyia flaviscutellata (50). Flagellate infections were detected in 45 flies. Of the 19 parasites isolated in vitro, 15 were Leishmania (Viannia) guyanensis (13 in Ny. umbratilis, 1 in Ny. whitmani, 1 in Ny. anduzei) and three were L. (V.) naiffi (2 in Ps. s. maripaensis, 1 in Ny. anduzei). The results indicate the participation of three phlebotomine species in the transmission of L. (V.) guyanensis and two species in that of L. (V.) naiffi, and show that the same phlebotomine species is involved in the transmission of different Leishmania (Viannia) species in the Guianan/Amazon region. A review of the literature together with the results of the present study, and other published and unpublished results, indicate that eight phlebotomine species potentially participate in the transmission of Leishmania (Viannia) naiffi in Amazonia. © A.A.A. de Souza et al., published by EDP Sciences, 2017.

  4. Ecological effects on arbovirus-mosquito cycles of transmission.

    Science.gov (United States)

    Tabachnick, Walter J

    2016-12-01

    Mosquitoes transmit many viruses to a variety of hosts. Cycles of mosquito borne arbovirus transmission are the result of complex interactions between the mosquito, the arbovirus and the host that are influenced by genetic variations in a variety of traits in each that are all influenced by many environmental factors. R 0 , the basic reproduction number or mean number of individuals infected from a single infected individual, is a measure of mosquito borne arbovirus transmission. Understanding the causes for the distribution of R 0 in any transmission cycle is a daunting challenge due to the lack of information on the genetic and environmental variances that influence R 0 . Information about the major factors influencing R 0 for specific transmission cycles is essential to develop efficient and effective strategies to reduce transmission in different cycles and locations. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Monetary transmission and business cycle asymmetry

    NARCIS (Netherlands)

    Kakes, Jan

    1998-01-01

    This paper investigates asymmetric effects of monetary policy over the business cycle. A two-state Markov Switching Model is employed to model both recessions and expansions. For the United States and Germany, strong evidence is found that monetary policy is more effective in a recession than during

  6. Business cycles and natural gas prices

    International Nuclear Information System (INIS)

    Apostolos, S.; Asghar, S.

    2005-01-01

    This paper investigates the basic stylised facts of natural gas price movements using data for the period that natural gas has been traded on an organised exchange and the methodology suggested by Kydland and Prescott (1990). Our results indicate that natural gas prices are procyclical and lag the cycle of industrial production. Moreover, natural gas prices are positively contemporaneously correlated with United States consumer prices and lead the cycle of consumer prices, raising the possibility that natural gas prices might be a useful guide for US monetary policy, like crude oil prices are, possibly serving as an important indicator variable. (author)

  7. Nature's third cycle a story of sunspots

    CERN Document Server

    Choudhuri, Arnab Rai

    2015-01-01

    The cycle of day and night and the cycle of seasons are two familiar natural cycles around which many human activities are organized. But is there a third natural cycle of importance for us humans? On 13 March 1989, six million people in Canada went without electricity for many hours: a large explosion on the sun was discovered as the cause of this blackout. Such explosions occur above sunspots, dark features on the surface of the Sun that have been observed through telescopes since the time of Galileo. The number of sunspots has been found to wax and wane over a period of 11 years. Although this cycle was discovered less than two centuries ago, it is becoming increasingly important for us as human society becomes more dependent on technology. For nearly a century after its discovery, the cause of the sunspot cycle remained completely shrouded in mystery. The 1908 discovery of strong magnetic fields in sunspots made it clear that the 11-year cycle is the magnetic cycle of the sun. It is only during the last ...

  8. Life cycle assessment of the transmission network in Great Britain

    International Nuclear Information System (INIS)

    Harrison, Gareth P.; Maclean, Edward J.; Karamanlis, Serafeim; Ochoa, Luis F.

    2010-01-01

    Analysis of lower carbon power systems has tended to focus on the operational carbon dioxide (CO 2 ) emissions from power stations. However, to achieve the large cuts required it is necessary to understand the whole-life contribution of all sectors of the electricity industry. Here, a preliminary assessment of the life cycle carbon emissions of the transmission network in Great Britain is presented. Using a 40-year period and assuming a static generation mix it shows that the carbon equivalent emissions (or global warming potential) of the transmission network are around 11 gCO 2-eq /kWh of electricity transmitted and that almost 19 times more energy is transmitted by the network than is used in its construction and operation. Operational emissions account for 96% of this with transmission losses alone totalling 85% and sulphur hexafluoride (SF 6 ) emissions featuring significantly. However, the CO 2 embodied within the raw materials of the network infrastructure itself represents a modest 3%. Transmission investment decisions informed by whole-life cycle carbon assessments of network design could balance higher financial and carbon 'capital' costs of larger conductors with lower transmission losses and CO 2 emissions over the network lifetime. This will, however, necessitate new regulatory approaches to properly incentivise transmission companies.

  9. Transmission of influenza reflects seasonality of wild birds across the annual cycle

    Science.gov (United States)

    Hill, Nichola J.; Ma, Eric J.; Meixell, Brandt W.; Lindberg, Mark S.; Boyce, Walter M.; Runstadler, Jonathan A.

    2016-01-01

    Influenza A Viruses (IAV) in nature must overcome shifting transmission barriers caused by the mobility of their primary host, migratory wild birds, that change throughout the annual cycle. Using a phylogenetic network of viral sequences from North American wild birds (2008–2011) we demonstrate a shift from intraspecific to interspecific transmission that along with reassortment, allows IAV to achieve viral flow across successive seasons from summer to winter. Our study supports amplification of IAV during summer breeding seeded by overwintering virus persisting locally and virus introduced from a wide range of latitudes. As birds migrate from breeding sites to lower latitudes, they become involved in transmission networks with greater connectivity to other bird species, with interspecies transmission of reassortant viruses peaking during the winter. We propose that switching transmission dynamics may be a critical strategy for pathogens that infect mobile hosts inhabiting regions with strong seasonality.

  10. Environmental analysis of natural gas life cycle

    International Nuclear Information System (INIS)

    Riva, A.; D'Angelosante, S.; Trebeschi, C.

    2000-01-01

    Life Cycle Assessment is a method aimed at identifying the environmental effects connected with a given product, process or activity during its whole life cycle. The evaluation of published studies and the application of the method to electricity production with fossil fuels, by using data from published databases and data collected by the gas industry, demonstrate the importance and difficulties to have reliable and updated data required for a significant life cycle assessment. The results show that the environmental advantages of natural gas over the other fossil fuels in the final use stage increase still further if the whole life cycle of the fuels, from production to final consumption, is taken into account [it

  11. 75 FR 42432 - Northern Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC...

    Science.gov (United States)

    2010-07-21

    ... Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC, Transcontinental... abandonment of facilities by Northern Natural Gas Company, Southern Natural Gas Company, Florida Gas... resources, fisheries, and wetlands; Cultural resources; Vegetation and wildlife; Endangered and threatened...

  12. Assessment of the role of small mammals in the transmission cycle of tegumentary leishmaniasis and first report of natural infection with Leishmania braziliensis in two sigmodontines in northeastern Argentina.

    Science.gov (United States)

    Fernández, María S; Fraschina, Jimena; Acardi, Soraya; Liotta, Domingo J; Lestani, Eduardo; Giuliani, Magalí; Busch, María; Salomón, O Daniel

    2018-02-01

    To contribute to the knowledge of the role of small mammals in the transmission cycle of tegumentary leishmaniasis caused by Leishmania braziliensis, we studied the small mammal community and its temporal and spatial association with phlebotominae, as well as small mammal infection by Leishmania spp. by PCR-RFLP analyses in an endemic area of northeastern Argentina. Ten small mammal samplings were conducted (2007-2009, 7506 Sherman trap nights and 422 cage trap nights). In two of these samplings, 16 capture stations each one consisting of a CDC light trap to capture phlebotominae, two to four Sherman traps and two cage traps were placed. We found co-occurrence of phlebotominae and small mammal captures in four stations, which were all the stations with small mammal captures and yielded 97% (2295 specimens, including 21 gravid females) of the total phlebotominae captures, suggesting that small mammals may provide a potential source of blood for phlebotominae females. One Didelphis albiventris and two Rattus rattus were associated with high captures of Nyssomyia whitmani, vector of L. braziliensis in the study area. The PCR-RFLP analyses confirm the presence of L. braziliensis in two sigmodontine small mammals (Akodon sp. and Euryoryzomys russatus) for the first time in Argentina, to our knowledge.

  13. Parasite transmission in a natural multihost-multiparasite community.

    Science.gov (United States)

    Auld, Stuart K J R; Searle, Catherine L; Duffy, Meghan A

    2017-05-05

    Understanding the transmission and dynamics of infectious diseases in natural communities requires understanding the extent to which the ecology, evolution and epidemiology of those diseases are shaped by alternative hosts. We performed laboratory experiments to test how parasite spillover affected traits associated with transmission in two co-occurring parasites: the bacterium Pasteuria ramosa and the fungus Metschnikowia bicuspidata Both parasites were capable of transmission from the reservoir host ( Daphnia dentifera ) to the spillover host ( Ceriodaphnia dubia ), but this occurred at a much higher rate for the fungus than the bacterium. We quantified transmission potential by combining information on parasite transmission and growth rate, and used this to compare parasite fitness in the two host species. For both parasites, transmission potential was lower in the spillover host. For the bacterium, virulence was higher in the spillover host. Transmission back to the original host was high for both parasites, with spillover influencing transmission rate of the fungus but not the bacterium. Thus, while inferior, the spillover host is not a dead-end for either parasite. Overall, our results demonstrate that the presence of multiple hosts in a community can have important consequences for disease transmission, and host and parasite fitness.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'. © 2017 The Author(s).

  14. Parasite transmission in a natural multihost–multiparasite community

    Science.gov (United States)

    2017-01-01

    Understanding the transmission and dynamics of infectious diseases in natural communities requires understanding the extent to which the ecology, evolution and epidemiology of those diseases are shaped by alternative hosts. We performed laboratory experiments to test how parasite spillover affected traits associated with transmission in two co-occurring parasites: the bacterium Pasteuria ramosa and the fungus Metschnikowia bicuspidata. Both parasites were capable of transmission from the reservoir host (Daphnia dentifera) to the spillover host (Ceriodaphnia dubia), but this occurred at a much higher rate for the fungus than the bacterium. We quantified transmission potential by combining information on parasite transmission and growth rate, and used this to compare parasite fitness in the two host species. For both parasites, transmission potential was lower in the spillover host. For the bacterium, virulence was higher in the spillover host. Transmission back to the original host was high for both parasites, with spillover influencing transmission rate of the fungus but not the bacterium. Thus, while inferior, the spillover host is not a dead-end for either parasite. Overall, our results demonstrate that the presence of multiple hosts in a community can have important consequences for disease transmission, and host and parasite fitness. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289264

  15. 75 FR 13524 - Northern Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC...

    Science.gov (United States)

    2010-03-22

    ... Natural Gas Company, Southern Natural Gas Company, Florida Gas Transmission Company, LLC, Transcontinental... notice that on March 5, 2010, Northern Natural Gas Company (Northern Natural), 1111 South 103rd Street, Omaha, Nebraska 68124- 1000, filed on behalf of itself and other owners, Southern Natural Gas Company...

  16. Natural Characteristics of The Herringbone Gear Transmission System

    Science.gov (United States)

    Zhou, Jianxing; Sun, Wenlei; Cao, Li

    2018-03-01

    According to the structure characteristics of herringbone gear transmission, a more realistic dynamic model of the transmission system is built in consideration of the inner excitation, herringbone gears axial positioning and sliding bearing etc. The natural frequencies of the system are calculated, and the vibration mode is divided into symmetric vibration modes and asymmetric vibration modes. The time history of system dynamic force is obtained by solving the dynamic model. The effects of the connection stiffness of left and right sides of herringbone gears and axial support stiffness on natural characteristics are discussed.

  17. Efficacy of natural cycle IVF: a review of the literature

    NARCIS (Netherlands)

    Pelinck, M. J.; Hoek, A.; Simons, A. H. M.; Heineman, M. J.

    2002-01-01

    Since the introduction of IVF treatments, natural cycle IVF has been largely replaced by IVF with ovarian stimulation. However, natural cycle IVF has several advantages. It is associated with a close to zero multiple pregnancy rate, and a zero risk of ovarian hyperstimulation syndrome. Per cycle,

  18. Efficacy of natural cycle IVF : a review of the literature

    NARCIS (Netherlands)

    Pelinck, MJ; Hoek, A; Simons, AHM; Heineman, MJ

    2002-01-01

    Since the introduction of IVF treatments, natural cycle IVF has been largely replaced by IVF with ovarian stimulation. However, natural cycle IVF has several advantages. It is associated with a close to zero multiple pregnancy rate, and a zero risk of ovarian hyperstimulation syndrome. Per cycle,

  19. Thermodynamic design of natural gas liquefaction cycles for offshore application

    Science.gov (United States)

    Chang, Ho-Myung; Lim, Hye Su; Choe, Kun Hyung

    2014-09-01

    A thermodynamic study is carried out for natural gas liquefaction cycles applicable to offshore floating plants, as partial efforts of an ongoing governmental project in Korea. For offshore liquefaction, the most suitable cycle may be different from the on-land LNG processes under operation, because compactness and simple operation are important as well as thermodynamic efficiency. As a turbine-based cycle, closed Claude cycle is proposed to use NG (natural gas) itself as refrigerant. The optimal condition for NG Claude cycle is determined with a process simulator (Aspen HYSYS), and the results are compared with fully-developed C3-MR (propane pre-cooled mixed refrigerant) JT cycles and various N2 (nitrogen) Brayton cycles in terms of efficiency and compactness. The newly proposed NG Claude cycle could be a good candidate for offshore LNG processes.

  20. Natural environment and the biogeochemical cycle s. Pt. A

    Energy Technology Data Exchange (ETDEWEB)

    Hutzinger, O [ed.

    1980-01-01

    At the moment three volumes of the handbook are planned. Volume 1 deals with the natural environment and the biogeochemical cycles therein, including some background information such as energetics and ecology. The individual chapters are dealing with the atmosphere, the hydrosphere, chemical oceanography, chemical aspects of soil, the cycle of oxygen, sulfur, and phosphorus, metal cycles and biological methylation, and natural organohalogen compounds. Separate abstracts are prepared for 5 chapters of this book.

  1. Biomes and Natural Cycles. [CD-ROM].

    Science.gov (United States)

    1996

    This interactive multimedia software illustrates and explains life on planet Earth through colorful and dynamic representations. Clear explanations and animation elucidate a variety of subjects such as the organization of the ecosphere, the flux of energy, water cycles, climates, and characteristics of regions across the globe. Five animated films…

  2. Trade flows as a channel for the transmission of business cycles

    OpenAIRE

    J.M. BERK

    1997-01-01

    The interdependence between business cycles of different countries has grown in recent decades. Many factors act as conductors of cyclical fluctuations between countries. In this context, the influence of trade flows in the global transmission of business cycles is examined. The author aims to identify empirically the line of causality of international cyclical movements as suggested by trade flows, presenting an estimate of the quantitive importance of trade flows as transmission channel.

  3. Magnetic Nature of Light Transmission through a 5-nm Gap.

    Science.gov (United States)

    Yang, Hyosim; Kim, Dai-Sik; Kim, Richard H Joon-Yeon; Ahn, Jae Sung; Kang, Taehee; Jeong, Jeeyoon; Lee, Dukhyung

    2018-02-09

    Slot antennas have been exploited as important building blocks of optical magnetism because their radiations are invoked by the magnetic fields along the axes, as vectorial Babinet principle predicts. However, optical magnetism of a few-nanometer-width slit, for which fascinating applications are found due to the colossal field enhancement but Babinet principle fails due to the nonnegligible thickness, has not been investigated. In this paper, we demonstrated that the magnetic field plays a dominant role in light transmission through a 5-nm slit on a 150-nm-thick gold film. The 5-nm slit was fabricated by atomic layer lithography, and the transmission was investigated for various incident angles by experiment and simulation at 785-nm wavelength. We found that, due to the deep subwavelength gap width, the transmission has the same incident angle dependence as the tangential magnetic field on the metal surface and this magnetic nature of a nanogap holds up to ~100-nm width. Our analysis establishes conditions for nanogap optical magnetism and suggests new possibilities in realizing magnetic-field-driven optical nonlinearities.

  4. Novel combined cycle configurations for propane pre-cooled mixed refrigerant (APCI) natural gas liquefaction cycle

    International Nuclear Information System (INIS)

    Mortazavi, Amir; Alabdulkarem, Abdullah; Hwang, Yunho; Radermacher, Reinhard

    2014-01-01

    Highlights: • 10 New LNG plants driver cycle enhancement configurations were developed. • All the 14 enhancement options design variables were optimized to demonstrate their energy saving potentials. • The best driver cycle enhancement option improved the driver cycle energy efficiency by 38%. • The effects of technological advancements on the performances of the enhancement options were studied. - Abstract: A significant amount of energy is required for natural gas liquefaction. Due to the production scale of LNG plants, they consume an intensive amount of energy. Consequently, any enhancement to the energy efficiency of LNG plants will result in a considerable reduction in natural gas consumption and CO 2 emission. Compressor drivers are the main energy consumer in the LNG plants. In this paper, 14 different driver cycle enhancement options were considered. A number of these options have not been proposed for the LNG plants. The new driver cycle development was performed by analyzing and optimizing the design variables of four conventional driver cycle enhancement options. The optimization results were used to develop more efficient cycles through mitigating the active constrains and driver cycle innovations. Based on the current available technologies five of our newly developed driver cycle configurations have higher efficiency than the most efficient existing conventional driver cycle. The best developed driver cycle enhancement option improved the base driver cycle energy efficiency by 38%. The effects of technological advancement on the performances of the all driver cycle enhancement options were also considered

  5. Research into the transmission of natural gas by gas pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Gadonneix, P.

    1998-12-31

    This paper is the press release of the talk given at the `Gaz de France scientific meeting with the press` by P. Gadonneix, chairman of Gaz de France company, on October 7, 1998. The aim of this talk concerns the new French and European supply link for bringing natural gas from the Norwegian North Sea fields. This new supply link is the first direct link between Norway and France and the NorFra gas pipeline which brings natural gas from the North Sea to France is the longest offshore pipeline in the world. The `Artere des Hauts de France` pipeline (the largest diameter gas pipeline ever laid in France) is devoted to the transfer of natural gas from Dunkerque to the Gournay-sur-Aronde underground storage site. This paper describes successively: the French European gas supply hub, the NorFra project, the Artere des Hauts de France pipeline, the network performance research, the safety and quality guaranties, the reduction of overland natural gas transmission costs (improvement of pipe-laying techniques and optimization of line route and welding operations), the specific techniques used for road and river crossing (micro-tunnel digging, river-crossing ditches) and for anchoring (buoyancy compensation). Finally, the environmental impact of the laying operations is briefly described. (J.S.)

  6. The Carbon Cycle: Teaching Youth about Natural Resource Sustainability

    Science.gov (United States)

    Warren, William A.

    2015-01-01

    The carbon cycle was used as a conceptual construct for organizing the curriculum for a youth summer camp on natural resource use and sustainability. Several studies have indicated the importance of non-traditional youth education settings for science education and understanding responsible natural resource use. The Sixth Grade Forestry Tour, a…

  7. Nitrogen expander cycles for large capacity liquefaction of natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ho-Myung; Park, Jae Hoon; Gwak, Kyung Hyun [Hong Ik University, Department of Mechanical Engineering, Seoul, 121-791 (Korea, Republic of); Choe, Kun Hyung [Korea Gas Corporation, Incheon, 406-130 (Korea, Republic of)

    2014-01-29

    Thermodynamic study is performed on nitrogen expander cycles for large capacity liquefaction of natural gas. In order to substantially increase the capacity, a Brayton refrigeration cycle with nitrogen expander was recently added to the cold end of the reputable propane pre-cooled mixed-refrigerant (C3-MR) process. Similar modifications with a nitrogen expander cycle are extensively investigated on a variety of cycle configurations. The existing and modified cycles are simulated with commercial process software (Aspen HYSYS) based on selected specifications. The results are compared in terms of thermodynamic efficiency, liquefaction capacity, and estimated size of heat exchangers. The combination of C3-MR with partial regeneration and pre-cooling of nitrogen expander cycle is recommended to have a great potential for high efficiency and large capacity.

  8. Nitrogen expander cycles for large capacity liquefaction of natural gas

    Science.gov (United States)

    Chang, Ho-Myung; Park, Jae Hoon; Gwak, Kyung Hyun; Choe, Kun Hyung

    2014-01-01

    Thermodynamic study is performed on nitrogen expander cycles for large capacity liquefaction of natural gas. In order to substantially increase the capacity, a Brayton refrigeration cycle with nitrogen expander was recently added to the cold end of the reputable propane pre-cooled mixed-refrigerant (C3-MR) process. Similar modifications with a nitrogen expander cycle are extensively investigated on a variety of cycle configurations. The existing and modified cycles are simulated with commercial process software (Aspen HYSYS) based on selected specifications. The results are compared in terms of thermodynamic efficiency, liquefaction capacity, and estimated size of heat exchangers. The combination of C3-MR with partial regeneration and pre-cooling of nitrogen expander cycle is recommended to have a great potential for high efficiency and large capacity.

  9. Nitrogen expander cycles for large capacity liquefaction of natural gas

    International Nuclear Information System (INIS)

    Chang, Ho-Myung; Park, Jae Hoon; Gwak, Kyung Hyun; Choe, Kun Hyung

    2014-01-01

    Thermodynamic study is performed on nitrogen expander cycles for large capacity liquefaction of natural gas. In order to substantially increase the capacity, a Brayton refrigeration cycle with nitrogen expander was recently added to the cold end of the reputable propane pre-cooled mixed-refrigerant (C3-MR) process. Similar modifications with a nitrogen expander cycle are extensively investigated on a variety of cycle configurations. The existing and modified cycles are simulated with commercial process software (Aspen HYSYS) based on selected specifications. The results are compared in terms of thermodynamic efficiency, liquefaction capacity, and estimated size of heat exchangers. The combination of C3-MR with partial regeneration and pre-cooling of nitrogen expander cycle is recommended to have a great potential for high efficiency and large capacity

  10. Natural gas supply in Denmark - A model of natural gas transmission and the liberalized gas market

    International Nuclear Information System (INIS)

    Bregnbaek, L.

    2005-01-01

    In the wake of the liberalization of European energy markets a large area of research has spawned. This area includes the development of mathematical models to analyze the impact of liberalization with respect to efficiency, supply security and environment, to name but a few subjects. This project describes the development of such a model. In Denmark the parallel liberalization of the markets of natural gas and electricity and the existence of an abundance of de-centralized combined heat and power generators of which most are natural gas fired, leads to the natural assumption that the future holds a greater deal of interdependency for these markets. A model is developed describing network flows in the natural gas transmission system, the main arteries of natural gas supply, from a technical viewpoint. This yields a technical bounding on the supply available in different parts of the country. Additionally the economic structure of the Danish natural gas market is formulated mathematically giving a description of the transmission, distribution and storage options available to the market. The supply and demand of natural gas is put into a partial equilibrium context by integrating the developed model with the Balmorel model, which describes the markets for electricity and district heat. Specifically on the demand side the consumption of natural gas for heat and power generation is emphasized. General results and three demonstration cases are presented to illustrate how the developed model can be used to analyze various energy policy issues, and to disclose the strengths and weaknesses in the formulation. (au)

  11. Natural cycle IVF with and without terminal HCG: learning from failed cycles.

    Science.gov (United States)

    Lenton, Elizabeth A

    2007-08-01

    Natural cycle IVF, without the use of LH down-regulation, is difficult because women start spontaneous LH surges at any time of the day and on any day of the week. This is not readily compatible with delivery of a routine IVF service and so historically the natural cycle has been modified by the use of human chorionic gonadotrophin (HCG) to make the natural cycle fit convenient clinical practice. This report re-evaluates data collected some years ago and seeks to determine whether the use of HCG is ultimately beneficial. Two large series of natural cycle IVF where only LH monitoring was performed (534 cycles) or where this was combined with HCG as necessary (241 cycles) were analysed. In essence, the use of HCG introduced as many problems as it overcame: there was no net benefit with respect to the number of eggs collected or clinical pregnancies generated. In fact there was an overall deterioration in all indices. The principle difficulties with natural cycle IVF are those associated with the prediction of follicle maturity and hence timing egg collection, and the conflict between costly and intrusively frequent monitoring with simpler but far less effective approaches.

  12. Cost function for the natural gas transmission, industry: further considerations

    International Nuclear Information System (INIS)

    Massol, Olivier

    2009-01-01

    This article studies the cost function for the natural gas transmission industry. 60 years ago, Hollis B. Chenery published an important contribution that demonstrated how, in that particular industry, the production function of micro-economic theory can be rewritten with engineering variables (Chenery, 1949). In 2008, an article published in The Engineering Economist (Yepez, 2008) provided a refreshing revival on Chenery's seminal thoughts. In addition to a tribute to the late H.B. Chenery, this document offers some further comments and extensions on Yepez (2008). It provides a statistically estimated characterisation of the long-run scale economies and a discussion on the short-run economics of the duplication of existing equipments. As a first extension, we study the optimal design for infrastructure that is planned to transport a seasonally-varying flow of natural gas. The second extension analyzes the optimal degree of excess capacity to be built into a new infrastructure by a firm that expects a random rise in its output during the infrastructure's lifetime. (author)

  13. A two years study on vectors of cutaneous Leishmaniasis. Evidence for sylvatic transmission cycle in the state of Campeche, Mexico.

    Science.gov (United States)

    Rebollar-Téllez, E A; Ramírez-Fraire, A; Andrade-Narvaez, F J

    1996-01-01

    Vectors of cutaneous leishmaniasis in the State of Campeche were studied in relation to the transmission cycle of Leishmania (Le.) mexicana. To determine how transmission of leishmaniasis occurs, we collected phlebotomine sand flies for two years. In the first year (October 1990 to November 1991) the collections were made with CDC light traps, Shannon traps and direct captures at natural shelters around the village (La Libertad. In the second year (February 1993 to January 1994) the catches were performed at 8 km southeast of La Libertad in the forest. Female sand flies were examined for Leishmania. During the first year, 347 sand flies of nine species were collected, most of which were Lutzomyia deleoni (61.3%). When all nine species were considered, more females than males were captured. Low densities of anthropophillic species of sand flies around the village indicated that sylvatic transmission was taking place. For the second year. 1484 sand flies of 16 species were caught. The most common were L. olmeca olmeca (21.7%), L. cruciata (19.2%) and L. ovallesi (14.1%). Similarly, more females were caught than males. Thirty-five females of five species were found infected with flagellates believed to be Leishmania sp. The highest infection rate was found in L. olmeca olmeca (7.1%) followed by L. cruciata (4.5%) and L. ovallesi (1.1%). These data plus other evidence on the epidemiology of human cases and results from reservoir studies are discussed in relation to the sylvatic transmission cycle.

  14. Proton cycling, buffering, and reaction stoichiometry in natural waters

    NARCIS (Netherlands)

    Hofmann, A.F.; Middelburg, J.J.; Soetaert, K.; Wolf-Gladrow, D.A.; Meysman, F.J.R.

    2010-01-01

    Ongoing acidification of the global ocean necessitates a solid understanding of how biogeochemical processes are driving proton cycling and observed pH changes in natural waters. The standard way of calculating the pH evolution of an aquatic system is to specify first how biogeochemical processes

  15. Life-cycle greenhouse gas emissions of shale gas, natural gas, coal, and petroleum.

    Science.gov (United States)

    Burnham, Andrew; Han, Jeongwoo; Clark, Corrie E; Wang, Michael; Dunn, Jennifer B; Palou-Rivera, Ignasi

    2012-01-17

    The technologies and practices that have enabled the recent boom in shale gas production have also brought attention to the environmental impacts of its use. It has been debated whether the fugitive methane emissions during natural gas production and transmission outweigh the lower carbon dioxide emissions during combustion when compared to coal and petroleum. Using the current state of knowledge of methane emissions from shale gas, conventional natural gas, coal, and petroleum, we estimated up-to-date life-cycle greenhouse gas emissions. In addition, we developed distribution functions for key parameters in each pathway to examine uncertainty and identify data gaps such as methane emissions from shale gas well completions and conventional natural gas liquid unloadings that need to be further addressed. Our base case results show that shale gas life-cycle emissions are 6% lower than conventional natural gas, 23% lower than gasoline, and 33% lower than coal. However, the range in values for shale and conventional gas overlap, so there is a statistical uncertainty whether shale gas emissions are indeed lower than conventional gas. Moreover, this life-cycle analysis, among other work in this area, provides insight on critical stages that the natural gas industry and government agencies can work together on to reduce the greenhouse gas footprint of natural gas.

  16. Life-cycle analysis of shale gas and natural gas.

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C.E.; Han, J.; Burnham, A.; Dunn, J.B.; Wang, M. (Energy Systems); ( EVS)

    2012-01-27

    The technologies and practices that have enabled the recent boom in shale gas production have also brought attention to the environmental impacts of its use. Using the current state of knowledge of the recovery, processing, and distribution of shale gas and conventional natural gas, we have estimated up-to-date, life-cycle greenhouse gas emissions. In addition, we have developed distribution functions for key parameters in each pathway to examine uncertainty and identify data gaps - such as methane emissions from shale gas well completions and conventional natural gas liquid unloadings - that need to be addressed further. Our base case results show that shale gas life-cycle emissions are 6% lower than those of conventional natural gas. However, the range in values for shale and conventional gas overlap, so there is a statistical uncertainty regarding whether shale gas emissions are indeed lower than conventional gas emissions. This life-cycle analysis provides insight into the critical stages in the natural gas industry where emissions occur and where opportunities exist to reduce the greenhouse gas footprint of natural gas.

  17. Fiat Chrysler Application for Alternative Methodology for Off-Cycle Technology Credits: Engine and Transmission Warmup

    Science.gov (United States)

    FCA Group LLC request to the EPA regarding greenhouse gas, off-cycle CO2 credits for Active Engine Warm Up used in 2011-2013 model year vehicles and Active Transmission Warm Up Technologies used in 2013 model year vehicles.

  18. Natural cycle in vitro fertilisation (IVF) for subfertile couples.

    Science.gov (United States)

    Allersma, Thomas; Farquhar, Cindy; Cantineau, Astrid E P

    2013-08-30

    Subfertility affects 15% to 20% of couples trying to conceive. In vitro fertilisation (IVF) is one of the assisted reproduction techniques developed to improve chances of achieving pregnancy. In the standard IVF method with controlled ovarian hyperstimulation (COH), growth and development of multiple follicles are stimulated by using gonadotrophins, often combined with a gonadotrophin-releasing hormone (GnRH) agonist or antagonist. Although it is an established method of conception for subfertile couples, the treatment is expensive and has a high risk of adverse effects. Studies have shown that IVF in a natural cycle (NC) or a modified natural cycle (MNC) might be a promising low risk and low cost alternative to the standard stimulated IVF treatment since the available dominant follicle of each cycle is used. In this review, we included available randomised controlled studies comparing natural cycle IVF (NC and MNC) with standard IVF. To compare the efficacy and safety of natural cycle IVF (including both NC-IVF and MNC-IVF) with controlled ovarian hyperstimulation IVF (COH-IVF) in subfertile couples. An extended search including of the Menstrual Disorders and Subfertility Group (MDSG) Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, ClinicalTrials.gov, conference abstracts in the Web of Knowledge, the World Health Organization International Trials Registry Platform search portal, LILACS database, PubMed and the OpenSIGLE database was conducted according to Cochrane guidelines. The last search was on 31st July 2013. All randomised controlled trials (RCTs) comparing either natural cycle IVF or modified natural cycle IVF versus standard IVF in subfertile couples were included. Data selection and extraction and risk of bias assessment were carried out independently by two authors (TA and AC). The primary outcome measures were live birth rate and ovarian hyperstimulation syndrome (OHSS) rate per randomised woman. We

  19. Borrelia bissettiae sp. nov. and Borrelia californiensis sp. nov. prevail in diverse enzootic transmission cycles.

    Science.gov (United States)

    Margos, Gabriele; Lane, Robert S; Fedorova, Natalia; Koloczek, Johannes; Piesman, Joseph; Hojgaard, Andrias; Sing, Andreas; Fingerle, Volker

    2016-03-01

    Two species of the genus Borrelia , Borrelia bissettiae sp. nov. and Borrelia californiensis sp. nov., were first described by Postic and co-workers on the basis of genetic analyses of several loci. Multilocus sequence analysis of eight housekeeping loci confirmed that these two Borrelia genomospecies are distinct members of the Borrelia burgdorferi sensu lato complex. B. bissettiae sp. nov. was initially described in transmission cycles involving Neotoma fuscipes wood rats and Ixodes pacificus ticks in California, and Neotoma mexicana and Ixodes spinipalpis in Colorado. The preferred host of B. californiensis sp. nov. appears to be the California kangaroo rat, Dipodomys californicus ; Ixodes jellisoni , I. spinipalipis and I. pacificus ticks are naturally infected with it. Thus, the ecological associations of the two genomospecies and their genetic distance from all other known Borrelia genomospecies species justify their description as separate genomospecies: B. bissettiae sp. nov. (type strain DN127 T  = DSM 17990 T  =  CIP 109136 T ) and B. californiensis (type strain CA446 T  = DSM 17989 T  = ATCC BAA-2689 T ).

  20. 78 FR 38309 - Northern Natural Gas Company; Southern Natural Gas Company, L.L.C.; Florida Gas Transmission...

    Science.gov (United States)

    2013-06-26

    ... Natural Gas Company; Southern Natural Gas Company, L.L.C.; Florida Gas Transmission Company, LLC; Notice of Application Take notice that on June 4, 2013, Northern Natural Gas Company (Northern), 1111 South 103rd Street, Omaha, Nebraska 68124; on behalf of itself, Southern Natural Gas Company, L.L.C., and...

  1. Estimating Externalities of Natural Gas Fuel Cycles, Report 4

    Energy Technology Data Exchange (ETDEWEB)

    Barnthouse, L.W.; Cada, G.F.; Cheng, M.-D.; Easterly, C.E.; Kroodsma, R.L.; Lee, R.; Shriner, D.S.; Tolbert, V.R.; Turner, R.S.

    1998-01-01

    This report describes methods for estimating the external costs (and possibly benefits) to human health and the environment that result from natural gas fuel cycles. Although the concept of externalities is far from simple or precise, it generally refers to effects on individuals' well being, that result from a production or market activity in which the individuals do not participate, or are not fully compensated. In the past two years, the methodological approach that this report describes has quickly become a worldwide standard for estimating externalities of fuel cycles. The approach is generally applicable to any fuel cycle in which a resource, such as coal, hydro, or biomass, is used to generate electric power. This particular report focuses on the production activities, pollution, and impacts when natural gas is used to generate electric power. In the 1990s, natural gas technologies have become, in many countries, the least expensive to build and operate. The scope of this report is on how to estimate the value of externalities--where value is defined as individuals' willingness to pay for beneficial effects, or to avoid undesirable ones. This report is about the methodologies to estimate these externalities, not about how to internalize them through regulations or other public policies. Notwithstanding this limit in scope, consideration of externalities can not be done without considering regulatory, insurance, and other considerations because these institutional factors affect whether costs (and benefits) are in fact external, or whether they are already somehow internalized within the electric power market. Although this report considers such factors to some extent, much analysis yet remains to assess the extent to which estimated costs are indeed external. This report is one of a series of reports on estimating the externalities of fuel cycles. The other reports are on the coal, oil, biomass, hydro, and nuclear fuel cycles, and on general

  2. Isotopic composition of chemical elements in natural cycles

    International Nuclear Information System (INIS)

    Wetzel, K.

    1977-12-01

    Mathematical models developed for planning and evaluating tracer experiments have been applied in investigations of the isotopic composition of carbon in its natural cycle through various periods of the last billion years. The influence on the natural isotope ratio due to industrial combustion of fossil fuels is shown. In order to describe regional differences from the global behaviour of carbon a parameter has been introduced, which represents the time needed for one total exchange of the atmosphere in a certain region with the global atmosphere

  3. Gait-Cycle-Driven Transmission Power Control Scheme for a Wireless Body Area Network.

    Science.gov (United States)

    Zang, Weilin; Li, Ye

    2018-05-01

    In a wireless body area network (WBAN), walking movements can result in rapid channel fluctuations, which severely degrade the performance of transmission power control (TPC) schemes. On the other hand, these channel fluctuations are often periodic and are time-synchronized with the user's gait cycle, since they are all driven from the walking movements. In this paper, we propose a novel gait-cycle-driven transmission power control (G-TPC) for a WBAN. The proposed G-TPC scheme reinforces the existing TPC scheme by exploiting the periodic channel fluctuation in the walking scenario. In the proposed scheme, the user's gait cycle information acquired by an accelerometer is used as beacons for arranging the transmissions at the time points with the ideal channel state. The specific transmission power is then determined by using received signal strength indication (RSSI). An experiment was conducted to evaluate the energy efficiency and reliability of the proposed G-TPC based on a CC2420 platform. The results reveal that compared to the original RSSI/link-quality-indication-based TPC, G-TPC reduces energy consumption by 25% on the sensor node and reduce the packet loss rate by 65%.

  4. Combined cycles and cogeneration with natural gas and alternative fuels

    International Nuclear Information System (INIS)

    Gusso, R.

    1992-01-01

    Since 1985 there has been a sharp increase world-wide in the sales of gas turbines. The main reasons for this are: the improved designs allowing better gas turbine and, thus, combined cycle efficiencies; the good fuel use indices in the the case of cogeneration; the versatility of the gas turbines even with poly-fuel plants; greatly limited exhaust emissions; and lower manufacturing costs and delivery times with respect to conventional plants. This paper after a brief discussion on the evolution in gas turbine applications in the world and in Italy, assesses their use and environmental impacts with fuels other than natural gas. The paper then reviews Italian efforts to develop power plants incorporating combined cycles and the gasification of coal, residual, and other low calorific value fuels

  5. Evaluation method for regional water cycle health based on nature-society water cycle theory

    Science.gov (United States)

    Zhang, Shanghong; Fan, Weiwei; Yi, Yujun; Zhao, Yong; Liu, Jiahong

    2017-08-01

    Regional water cycles increasingly reflect the dual influences of natural and social processes, and are affected by global climate change and expanding human activities. Understanding how to maintain a healthy state of the water cycle has become an important proposition for sustainable development of human society. In this paper, natural-social attributes of the water cycle are synthesized and 19 evaluation indices are selected from four dimensions, i.e., water-based ecosystem integrity, water quality, water resource abundance and water resource use. A hierarchical water-cycle health evaluation system is established. An analytic hierarchy process is used to set the weight of the criteria layer and index layer, and the health threshold for each index is defined. Finally, a water-cycle health composite-index assessment model and fuzzy recognition model are constructed based on the comprehensive index method and fuzzy mathematics theory. The model is used to evaluate the state of health of the water cycle in Beijing during 2010-2014 and in the planning year (late 2014), considering the transfer of 1 billion m3 of water by the South-to-North Water Diversion Project (SNWDP). The results show health scores for Beijing of 2.87, 3.10, 3.38, 3.11 and 3.02 during 2010-2014. The results of fuzzy recognition show that the sub-healthy grade accounted for 54%, 49%, 61% and 49% of the total score, and all years had a sub-healthy state. Results of the criteria layer analysis show that water ecosystem function, water quality and water use were all at the sub-healthy level and that water abundance was at the lowest, or sick, level. With the water transfer from the SNWDP, the health score of the water cycle in Beijing reached 4.04. The healthy grade accounted for 60% of the total score, and the water cycle system was generally in a healthy state. Beijing's water cycle health level is expected to further improve with increasing water diversion from the SNWDP and industrial

  6. A two years study on vectors of cutaneous leishmaniasis: Evidence for sylvatic transmission cycle in the State of Campeche, Mexico

    Directory of Open Access Journals (Sweden)

    Eduardo A Rebollar-Téllez

    1996-10-01

    Full Text Available Vectors of cutaneous leishmaniasis in the State of Campeche were studied in relation to the transmission cycle of Leishmania (Le. mexicana. To determine how transmission of leishmaniasis occurs, we collected phlebotomine sand flies for two years. In the first year (October 1990 to November 1991 the collections were made with CDC light traps, Shannon traps and direct captures at natural shelters around the village (<200 m of La Libertad. In the second year (February 1993 to January 1994 the catches were performed at 8 km southeast of La Libertad in the forest. Female sand flies were examined for Leishmania. During the first year, 347 sand flies of nine species were collected, most of which were Lutzomyia deleoni (61.3%. When all nine species were considered, more females than males were captured. Low densities of anthropophillic species of sand flies around the village indicated that sylvatic transmission was taking place. For the second year, 1484 sand flies of 16 species were caught. The most common were L. olmeca olmeca (21.7%, L. cruciata (19.2% and L. ovallesi (14.1%. Similarly, more females were caught than males. Thirty-five females of five species were found infected with flagellates believed to be Leishmania sp. The highest infection rate was found in L. olmeca olmeca (7.1% followed by L. cruciata (4.5% and L. ovallesi (1.1%. These data plus other evidence on the epidemiology of human cases and results from reservoir studies are discussed in relation to the sylvatic transmission cycle.

  7. Helicobacter pylori genomic microevolution during naturally occurring transmission between adults.

    Directory of Open Access Journals (Sweden)

    Bodo Linz

    Full Text Available The human gastric pathogen Helicobacter pylori is usually acquired during childhood and, in the absence of treatment, chronic infection persists through most of the host's life. However, the frequency and importance of H. pylori transmission between adults is underestimated. Here we sequenced the complete genomes of H. pylori strains that were transmitted between spouses and analysed the genomic changes. Similar to H. pylori from chronic infection, a significantly high proportion of the determined 31 SNPs and 10 recombinant DNA fragments affected genes of the hop family of outer membrane proteins, some of which are known to be adhesins. In addition, changes in a fucosyltransferase gene modified the LPS component of the bacterial cell surface, suggesting strong diversifying selection. In contrast, virulence factor genes were not affected by the genomic changes. We propose a model of the genomic changes that are associated with the transmission and adaptation of H. pylori to a new human host.

  8. Natural transmission of feline immunodeficiency virus from infected queen to kitten

    Directory of Open Access Journals (Sweden)

    Medeiros Sheila de

    2012-05-01

    Full Text Available Abstract Background Feline immunodeficiency virus (FIV is a naturally occurring lentivirus that infects cats. The primary mode of transmission occurs through bite wounds, and other routes are difficult to observe in nature. Findings The purpose of this study was to evaluate FIV transmission from queen to kitten in a colony of naturally infected stray cats. With this aim, a queen was monitored over a period of three years. A blood sample was taken to amplify and sequence gag, pol and env regions of the virus from the queen, two kittens and other cats from the colony. Conclusion Phylogenetic analysis showed evidence of queen to kitten transmission.

  9. Natural transmission of feline immunodeficiency virus from infected queen to kitten.

    Science.gov (United States)

    Medeiros, Sheila de Oliveira; Martins, Angelica Nascimento; Dias, Carlos Gabriel Almeida; Tanuri, Amilcar; Brindeiro, Rodrigo de Moraes

    2012-05-25

    Feline immunodeficiency virus (FIV) is a naturally occurring lentivirus that infects cats. The primary mode of transmission occurs through bite wounds, and other routes are difficult to observe in nature. The purpose of this study was to evaluate FIV transmission from queen to kitten in a colony of naturally infected stray cats. With this aim, a queen was monitored over a period of three years. A blood sample was taken to amplify and sequence gag, pol and env regions of the virus from the queen, two kittens and other cats from the colony. Phylogenetic analysis showed evidence of queen to kitten transmission.

  10. 78 FR 44900 - Communication of Operational Information Between Natural Gas Pipelines and Electric Transmission...

    Science.gov (United States)

    2013-07-25

    ... Regional Transmission Organizations and Independent System Operators (RTOs/ISOs) also noted that, although... operator from discussions between RTOs/ ISOs and natural gas pipelines regarding the status of a generator... not customers of electric transmission operators. Likewise, in the case of RTOs/ISOs, they are not...

  11. Transmission of naturally occurring lymphoma in macaque monkeys.

    OpenAIRE

    Hunt, R D; Blake, B J; Chalifoux, L V; Sehgal, P K; King, N W; Letvin, N L

    1983-01-01

    Spontaneously occurring rhesus monkey lymphomas were transmitted into healthy rhesus monkeys by using tumor cell suspensions. The naturally arising tumors included an immunoblastic sarcoma and an undifferentiated lymphoma. Recipient animals developed undifferentiated lymphomas, poorly differentiated lymphomas, or parenchymal lymphoproliferative abnormalities suggestive of early lesions of lymphoma. Some of these animals developed such opportunistic infections as cytomegalovirus hepatitis and ...

  12. The effect of elevated progesterone levels before HCG triggering in modified natural cycle frozen-thawed embryo transfer cycles

    DEFF Research Database (Denmark)

    Groenewoud, Eva R; Macklon, Nick S; Cohlen, Ben J

    2017-01-01

    follicular phase progesterone levels may occur in unstimulated cycles before frozen-thawed embryo transfer, or what affect they may have on outcomes. In this cohort study, 271 patients randomized to the modified natural cycle arm of a randomized controlled trial comparing two endometrial preparation regimens....... Whether monitoring of progesterone and LH in natural cycle frozen-thawed embryo transfer has added clinical value should studied further....

  13. First record of natural vertical transmission of dengue virus in Aedes aegypti from Cuba.

    Science.gov (United States)

    Gutiérrez-Bugallo, Gladys; Rodriguez-Roche, Rosmari; Díaz, Gisell; Vázquez, Antonio A; Alvarez, Mayling; Rodríguez, Magdalena; Bisset, Juan A; Guzman, Maria G

    2017-10-01

    While horizontal transmission (human-mosquito-human) of dengue viruses largely determines the epidemiology of the disease, vertical transmission (infected female mosquito- infected offspring) has been suggested as a mechanism that ensures maintenance of the virus during adverse conditions for horizontal transmission to occur. The purpose of this study was to analyze the natural infection of larval stages of Aedes aegypti (Diptera: Culicidae) with the dengue virus (DENV) in Cuba. Here, we report vertical transmission of DENV-3 genotype III in natural populations of Ae. aegypti through RT-PCR detection and serotyping plus sequencing. Our report constitutes the first record of vertical transmission of DENV in Ae. aegypti from Cuba with details of its serotype and genotype. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Influence of laboratory animal hosts on the life cycle of Hyalomma marginatum and implications for an in vivo transmission model for Crimean-Congo hemorrhagic fever virus

    Directory of Open Access Journals (Sweden)

    Aysen eGargili

    2013-08-01

    Full Text Available Crimean-Congo hemorrhagic fever virus (CCHFV is one of the most geographically widespread arboviruses and causes a severe hemorrhagic syndrome in humans. The virus circulates in nature in a vertebrate-tick cycle and ticks of the genus Hyalomma are the main vectors and reservoirs. Although the tick vector plays a central role in the maintenance and transmission of CCHFV in nature, comparatively little is known of CCHFV-tick interactions. This is mostly due to the fact that establishing tick colonies is laborious, and working with CCHFV requires a biosafety level 4 laboratory (BSL4 in many countries. Nonetheless, an in vivo transmission model is essential to understand the epidemiology of the transmission cycle of CCHFV. In addition, important parameters such as vectorial capacity of tick species, levels of infection in the host necessary to infect the tick, and aspects of virus transmission by tick bite including the influence of tick saliva, cannot be investigated any other way. Here, we evaluate the influence of different laboratory animal species as hosts supporting the life cycle of Hyalomma marginatum, a two-host tick. Rabbits were considered the host of choice for the maintenance of the uninfected colonies due to high larval attachment rates, shorter larval-nymphal feeding times, higher nymphal molting rates, high egg hatching rates and higher conversion efficiency index. Furthermore, we describe the successful establishment of an in vivo transmission model CCHFV in a BSL4 biocontainment setting using interferon knockout mice. This will give us a new tool to study the transmission and interaction of CCHFV with its tick vector.

  15. Natural plant sugar sources of Anopheles mosquitoes strongly impact malaria transmission potential.

    Directory of Open Access Journals (Sweden)

    Weidong Gu

    Full Text Available An improved knowledge of mosquito life history could strengthen malaria vector control efforts that primarily focus on killing mosquitoes indoors using insecticide treated nets and indoor residual spraying. Natural sugar sources, usually floral nectars of plants, are a primary energy resource for adult mosquitoes but their role in regulating the dynamics of mosquito populations is unclear. To determine how the sugar availability impacts Anopheles sergentii populations, mark-release-recapture studies were conducted in two oases in Israel with either absence or presence of the local primary sugar source, flowering Acacia raddiana trees. Compared with population estimates from the sugar-rich oasis, An. sergentii in the sugar-poor oasis showed smaller population size (37,494 vs. 85,595, lower survival rates (0.72 vs. 0.93, and prolonged gonotrophic cycles (3.33 vs. 2.36 days. The estimated number of females older than the extrinsic incubation period of malaria (10 days in the sugar rich site was 4 times greater than in the sugar poor site. Sugar feeding detected in mosquito guts in the sugar-rich site was significantly higher (73% than in the sugar-poor site (48%. In contrast, plant tissue feeding (poor quality sugar source in the sugar-rich habitat was much less (0.3% than in the sugar-poor site (30%. More important, the estimated vectorial capacity, a standard measure of malaria transmission potential, was more than 250-fold higher in the sugar-rich oasis than that in the sugar-poor site. Our results convincingly show that the availability of sugar sources in the local environment is a major determinant regulating the dynamics of mosquito populations and their vector potential, suggesting that control interventions targeting sugar-feeding mosquitoes pose a promising tactic for combating transmission of malaria parasites and other pathogens.

  16. Life Cycle Assessment on a 765 kV Venezuelan Transmission System

    International Nuclear Information System (INIS)

    Wang, Wenlu; Tremouille, Gilles; Beroual, Abderrahmane; Bessede, Jean-Luc

    2011-03-01

    The demand to preserve the environment and form a sustainable development is greatly increasing in the recent decades all over the world, and this environmental concern is also merged in electrical power industry, resulting in many eco-design approaches in T and D industries. As a method of eco-design, Life Cycle Assessment (LCA) is a systematic tool that enables the assessment of the environmental impacts of a product or service throughout its entire life cycle, i.e. raw material production, manufacture, distribution, use and disposal including all intervening transportation steps necessary or caused by the product's existence. In T and D industries, LCA has been done for a lot of products individually, in order to see one product's environmental impacts and to seek for ways of improving its environmental performance. This eco-design for product approach is a rather well-developed trend, however, as only a single electrical product cannot provide the electrical power to users, electrical system consists of a huge number of components, in order to investigate system's environmental profile, the entire environmental profiles of different composing products has to be integrated systematically, that is to say, a system approach is needed. Under this philosophy, in this paper, an LCA using SimaPro (one kind of LCA software) is conducted on a whole Venezuelan 765 kV AC transmission system, which transmits 8000 MW hydro-electrical power through 760 km to this country's load centers, with total 7 substations, i.e. one sending end, 2 intermediate substations and 4 receiving ends. This LCA includes both transmission lines and substations, and then the environmental impacts of the whole transmission system are investigated. (authors)

  17. Model documentation: Natural gas transmission and distribution model of the National Energy Modeling System. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-17

    The Natural Gas Transmission and Distribution Model (NGTDM) is the component of the National Energy Modeling System (NEMS) that is used to represent the domestic natural gas transmission and distribution system. NEMS was developed in the Office of integrated Analysis and Forecasting of the Energy information Administration (EIA). NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the EIA and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. The NGTDM is the model within the NEMS that represents the transmission, distribution, and pricing of natural gas. The model also includes representations of the end-use demand for natural gas, the production of domestic natural gas, and the availability of natural gas traded on the international market based on information received from other NEMS models. The NGTDM determines the flow of natural gas in an aggregate, domestic pipeline network, connecting domestic and foreign supply regions with 12 demand regions. The methodology employed allows the analysis of impacts of regional capacity constraints in the interstate natural gas pipeline network and the identification of pipeline capacity expansion requirements. There is an explicit representation of core and noncore markets for natural gas transmission and distribution services, and the key components of pipeline tariffs are represented in a pricing algorithm. Natural gas pricing and flow patterns are derived by obtaining a market equilibrium across the three main elements of the natural gas market: the supply element, the demand element, and the transmission and distribution network that links them. The NGTDM consists of four modules: the Annual Flow Module, the Capacity F-expansion Module, the Pipeline Tariff Module, and the Distributor Tariff Module. A model abstract is provided in Appendix A.

  18. Model documentation: Natural gas transmission and distribution model of the National Energy Modeling System. Volume 1

    International Nuclear Information System (INIS)

    1995-01-01

    The Natural Gas Transmission and Distribution Model (NGTDM) is the component of the National Energy Modeling System (NEMS) that is used to represent the domestic natural gas transmission and distribution system. NEMS was developed in the Office of integrated Analysis and Forecasting of the Energy information Administration (EIA). NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the EIA and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. The NGTDM is the model within the NEMS that represents the transmission, distribution, and pricing of natural gas. The model also includes representations of the end-use demand for natural gas, the production of domestic natural gas, and the availability of natural gas traded on the international market based on information received from other NEMS models. The NGTDM determines the flow of natural gas in an aggregate, domestic pipeline network, connecting domestic and foreign supply regions with 12 demand regions. The methodology employed allows the analysis of impacts of regional capacity constraints in the interstate natural gas pipeline network and the identification of pipeline capacity expansion requirements. There is an explicit representation of core and noncore markets for natural gas transmission and distribution services, and the key components of pipeline tariffs are represented in a pricing algorithm. Natural gas pricing and flow patterns are derived by obtaining a market equilibrium across the three main elements of the natural gas market: the supply element, the demand element, and the transmission and distribution network that links them. The NGTDM consists of four modules: the Annual Flow Module, the Capacity F-expansion Module, the Pipeline Tariff Module, and the Distributor Tariff Module. A model abstract is provided in Appendix A

  19. Technical comparison between Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Pablo Andres Silva; Venturini, Osvaldo Jose; Lora, Electo Eduardo Silva [Federal University of Itajuba - UNIFEI, MG (Brazil). Excellence Group in Thermal Power and Distributed Generation - NEST], e-mails: osvaldo@unifei.edu.br, electo@unifei.edu.br

    2010-07-01

    Among the emerging clean coal technologies for power generation, Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) systems are receiving considerable attention as a potentially attractive option to reduce the emissions of greenhouse gases (GHG). The main reason is because these systems has high efficiency and low emissions in comparison with traditional power generation plants. Currently in IGCC and NGCC systems at demonstration stage is been considered to implement CCS technology. CO{sub 2} emissions can be avoided in a gasification-based power plant because by transferring almost all carbon compounds to CO{sub 2} through the water gas shift (WGS) reaction, then removing the CO{sub 2} before it is diluted in the combustion stage. The aim of this study is to compare the technical performance of an IGCC system that uses Brazilian coal and petroleum coke as fuel with a NGCC system, with the same fixed output power of 450 MW. The first section of this paper presents the plant configurations of IGCC systems. The following section presents an analysis of NGCC technology. (author)

  20. Natural characteristics analysis of two teeth difference external compound planet transmission

    Directory of Open Access Journals (Sweden)

    Youdong YE

    2016-12-01

    Full Text Available An analytical translational-rotational-coupling dynamic model is developed to evaluate the natural characteristics of two teeth difference external compound planet transmission by adopting centralized parameters method. The governing differential equations are established by deriving relative displacement relationships between all motional components, and Matlab is used to calculate and obtain the natural frequencies and free vibration modes of the transmission system. The analysis results show that the vibration modes are classified into rotational mode of the central members, translational mode of the central members and complicate vibration mode of the planetary gears. The vibration modes are different from the NGW planetary transmission, and especially the planetary gears vibration mode are quite complex with several different vibration modes. The research can provide useful reference for preventing resonance, vibration and noise reduction, and structure optimization of the planet transmission mode used in polishing grinding.

  1. Horizontal transmission of Paranosema locustae (Microsporidia) in grasshopper populations via predatory natural enemies.

    Science.gov (United States)

    Wang-Peng, Shi; Zheng, Xuan; Jia, Wan-Tong; Li, Ao-Mei; Camara, Ibrahima; Chen, Hong-Xing; Tan, Shu-Qian; Liu, Yi-Qing; Ji, Rong

    2018-04-24

    Paranosema locustae Canning, 1953 (Microsporidia) provides effective control of grasshoppers. While horizontal transmission of P. locustae is known to occur, evidence for the mechanisms of such transmission via predatory natural enemies was found. We conducted a three-year laboratory and field study to assess the potential impact of feces both from grasshoppers Locusta migratoria L. and from their natural enemies on the persistence of P. locustae. We found that P. locustae persisted among grasshopper populations in treated areas and in adjacent untreated areas for up to two years, and the density of grasshoppers decreased in both areas. We showed that healthy grasshoppers could be infected by feeding on food contaminated by feces from their natural enemies. Predators of grasshoppers retained a large number of spores acquired from eating grasshoppers infected with P. locustae. Spores in the feces of the main natural enemy, the beetle Pterostichus gebleri Dejean 1828 in treated area showed clear viability. These results demonstrate that predatory natural enemies are important vectors for this microsporidian disease, and suggest that sustainable transmission and continuing population suppression might be achieved by horizontal transmission through natural enemies, which should be maximized to increase the effectiveness of P. locustae. This article is protected by copyright. All rights reserved.

  2. Critical Knowledge Gaps in Our Understanding of Environmental Cycling and Transmission of Leptospira spp.

    Science.gov (United States)

    Barragan, Veronica; Olivas, Sonora; Keim, Paul; Pearson, Talima

    2017-10-01

    Exposure to soil or water contaminated with the urine of Leptospira -infected animals is the most common way in which humans contract leptospirosis. Entire populations can be at high risk of leptospirosis while working in inundated fields, when engaging in aquatic sports, or after periods of heavy rainfall. The risk of infection after contact with these environmental sources depends on the ability of Leptospira bacteria to survive, persist, and infect new hosts. Multiple variables such as soil and water pH, temperature, and even environmental microbial communities are likely to shape the environmental conditions needed by the pathogen to persist. Here we review what is known about the environmental phase of the infectious Leptospira transmission cycle and identify knowledge gaps that will serve as a guide for future research. Copyright © 2017 Barragan et al.

  3. Cycle-by-cycle variations in a spark ignition engine fueled with natural gas-hydrogen blends combined with EGR

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Bin; Hu, Erjiang; Huang, Zuohua; Zheng, Jianjun; Liu, Bing; Jiang, Deming [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, 710049 Xi' an (China)

    2009-10-15

    Study of cycle-by-cycle variations in a spark ignition engine fueled with natural gas-hydrogen blends combined with exhaust gas recirculation (EGR) was conducted. The effects of EGR ratio and hydrogen fraction on engine cycle-by-cycle variations are analyzed. The results show that the cylinder peak pressure, the maximum rate of pressure rise and the indicated mean effective pressure decrease and cycle-by-cycle variations increase with the increase of EGR ratio. Interdependency between the above parameters and their corresponding crank angles of cylinder peak pressure is decreased with the increase of EGR ratio. For a given EGR ratio, combustion stability is promoted and cycle-by-cycle variations are decreased with the increase of hydrogen fraction in the fuel blends. Non-linear relationship is presented between the indicated mean effective pressure and EGR ratio. Slight influence of EGR ratio on indicated mean effective pressure is observed at low EGR ratios while large influence of EGR ratio on indicated mean effective pressure is demonstrated at high EGR ratios. The high test engine speed has lower cycle-by-cycle variations due to the enhancement of air flow turbulence and swirls in the cylinder. Increasing hydrogen fraction can maintain low cycle-by-cycle variations at high EGR ratios. (author)

  4. Cycle-by-cycle exhaust temperature monitoring for detection of misfiring and combustion instability in reciprocating natural gas engines

    Energy Technology Data Exchange (ETDEWEB)

    Gardiner, D.P. [Nexum Research Corp., Kingston, ON (Canada); Bardon, M.F. [Royal Military Coll. of Canada, Kingston, ON (Canada). Dept. of Mechanical Engineering

    2007-07-01

    The effectiveness of a cycle-by-cycle exhaust temperature monitoring system on engines operating at or near their fully rate load capacity was examined. Tests were conducted on stationary industrial natural gas engines. The study evaluated the monitoring system's ability to detect isolated single misfires, as well as combustion instability during misfire-free operations when the air/fuel ratio of the engine was adjusted to progressively lower settings. The combustion instability level of the engines was quantified by determining the relative variability of the groups of consecutive cycles. The coefficient of variation of indicated mean effective pressure (COV of IMEP) was used to examine cyclic variability. A combustion instability index was used to quantify cyclic variability with cycle-by-cycle exhaust temperature monitoring. Two engines were tested, notably a Cummins QSK 19G turbocharged natural gas engine; and a Waukesha VHP L5790G industrial natural gas engine. The tests demonstrated that cycle-by-cycle exhaust temperature monitoring system was capable of detecting misfiring and combustion instabilities in natural gas engines. 6 refs., 9 figs.

  5. Natural Gas Transmission and Distribution Model of the National Energy Modeling System. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    The Natural Gas Transmission and Distribution Model (NGTDM) is the component of the National Energy Modeling System (NEMS) that is used to represent the domestic natural gas transmission and distribution system. The NGTDM is the model within the NEMS that represents the transmission, distribution, and pricing of natural gas. The model also includes representations of the end-use demand for natural gas, the production of domestic natural gas, and the availability of natural gas traded on the international market based on information received from other NEMS models. The NGTDM determines the flow of natural gas in an aggregate, domestic pipeline network, connecting domestic and foreign supply regions with 12 demand regions. The purpose of this report is to provide a reference document for model analysts, users, and the public that defines the objectives of the model, describes its basic design, provides detail on the methodology employed, and describes the model inputs, outputs, and key assumptions. Subsequent chapters of this report provide: an overview of NGTDM; a description of the interface between the NEMS and NGTDM; an overview of the solution methodology of the NGTDM; the solution methodology for the Annual Flow Module; the solution methodology for the Distributor Tariff Module; the solution methodology for the Capacity Expansion Module; the solution methodology for the Pipeline Tariff Module; and a description of model assumptions, inputs, and outputs.

  6. Zika virus transmission to mouse ear by mosquito bite: a laboratory model that replicates the natural transmission process.

    Science.gov (United States)

    Secundino, Nagila Francinete Costa; Chaves, Barbara Aparecida; Orfano, Alessandra Silva; Silveira, Karine Renata Dias; Rodrigues, Nilton Barnabe; Campolina, Thais Bonifácio; Nacif-Pimenta, Rafael; Villegas, Luiz Eduardo Martinez; Silva, Breno Melo; Lacerda, Marcus Vinícius Guimarães; Norris, Douglas Eric; Pimenta, Paulo Filemon Paolucci

    2017-07-20

    Zika disease has transformed into a serious global health problem due to the rapid spread of the arbovirus and alarming severity including congenital complications, microcephaly and Guillain-Barré syndrome. Zika virus (ZIKV) is primarily transmitted to humans through the bite of an infective mosquito, with Aedes aegypti being the main vector. We successfully developed a ZIKV experimental transmission model by single infectious Ae. aegypti bite to a laboratory mouse using circulating Brazilian strains of both arbovirus and vector. Mosquitoes were orally infected and single Ae. aegypti were allowed to feed on mouse ears 14 days post-infection. Additionally, salivary gland (SG) homogenates from infected mosquitoes were intrathoracically inoculated into naïve Ae. aegypti. Mosquito and mouse tissue samples were cultured in C6/36 cells and processed by quantitative real-time PCR. A total of 26 Ae. aegypti were allowed to feed individually on mouse ears. Of these, 17 mosquitoes fed, all to full engorgement. The transmission rate of ZIKV by bite from these engorged mosquitoes to mouse ears was 100%. The amount of virus inoculated into the ears by bites ranged from 2 × 10 2 -2.1 × 10 10 ZIKV cDNA copies and was positively correlated with ZIKV cDNA quantified from SGs dissected from mosquitoes post-feeding. Replicating ZIKV was confirmed in macerated SGs (2.45 × 10 7 cDNA copies), mouse ear tissue (1.15 × 10 3 cDNA copies, and mosquitoes 14 days post-intrathoracic inoculation (1.49 × 10 7 cDNA copies) by cytopathic effect in C6/36 cell culture and qPCR. Our model illustrates successful transmission of ZIKV by an infectious mosquito bite to a live vertebrate host. This approach offers a comprehensive tool for evaluating the development of infection in and transmission from mosquitoes, and the vertebrate-ZIKV interaction and progression of infection following a natural transmission process.

  7. Understanding the life cycle surface land requirements of natural gas-fired electricity

    Science.gov (United States)

    Jordaan, Sarah M.; Heath, Garvin A.; Macknick, Jordan; Bush, Brian W.; Mohammadi, Ehsan; Ben-Horin, Dan; Urrea, Victoria; Marceau, Danielle

    2017-10-01

    The surface land use of fossil fuel acquisition and utilization has not been well characterized, inhibiting consistent comparisons of different electricity generation technologies. Here we present a method for robust estimation of the life cycle land use of electricity generated from natural gas through a case study that includes inventories of infrastructure, satellite imagery and well-level production. Approximately 500 sites in the Barnett Shale of Texas were sampled across five life cycle stages (production, gathering, processing, transmission and power generation). Total land use (0.62 m2 MWh-1, 95% confidence intervals ±0.01 m2 MWh-1) was dominated by midstream infrastructure, particularly pipelines (74%). Our results were sensitive to power plant heat rate (85-190% of the base case), facility lifetime (89-169%), number of wells per site (16-100%), well lifetime (92-154%) and pipeline right of way (58-142%). When replicated for other gas-producing regions and different fuels, our approach offers a route to enable empirically grounded comparisons of the land footprint of energy choices.

  8. Price and volatility transmissions between natural gas, fertilizer, and corn markets

    NARCIS (Netherlands)

    Etienne, Xiaoli Liao; Trujillo-Barrera, Andrés; Wiggins, Seth

    2016-01-01

    Purpose – The purpose of this paper is to investigate the price and volatility transmission between natural gas, fertilizer (ammonia), and corn markets, an issue that has been traditionally ignored in the literature despite its significant importance. Design/methodology/approach – The authors

  9. Analysis and consideration for the US criteria of nuclear fuel cycle facilities to resist natural disasters

    International Nuclear Information System (INIS)

    Shen Hong

    2013-01-01

    Natural disasters pose a threat to the safety of nuclear facilities. Fukushima nuclear accident tells us that nuclear safety in siting, design and construction shall be strengthened in case of external events caused by natural disasters. This paper first analyzes the DOE criteria of nuclear fuel cycle facilities to resist natural disasters. Then to develop our national criteria for natural disaster resistance of nuclear fuel cycle facilities is suggested, so as to ensure the safety of these facilities. (authors)

  10. Identifying the age cohort responsible for transmission in a natural outbreak of Bordetella bronchiseptica.

    Directory of Open Access Journals (Sweden)

    Gráinne H Long

    2010-12-01

    Full Text Available Identifying the major routes of disease transmission and reservoirs of infection are needed to increase our understanding of disease dynamics and improve disease control. Despite this, transmission events are rarely observed directly. Here we had the unique opportunity to study natural transmission of Bordetella bronchiseptica--a directly transmitted respiratory pathogen with a wide mammalian host range, including sporadic infection of humans--within a commercial rabbitry to evaluate the relative effects of sex and age on the transmission dynamics therein. We did this by developing an a priori set of hypotheses outlining how natural B. bronchiseptica infections may be transmitted between rabbits. We discriminated between these hypotheses by using force-of-infection estimates coupled with random effects binomial regression analysis of B. bronchiseptica age-prevalence data from within our rabbit population. Force-of-infection analysis allowed us to quantify the apparent prevalence of B. bronchiseptica while correcting for age structure. To determine whether transmission is largely within social groups (in this case litter, or from an external group, we used random-effect binomial regression to evaluate the importance of social mixing in disease spread. Between these two approaches our results support young weanlings--as opposed to, for example, breeder or maternal cohorts--as the age cohort primarily responsible for B. bronchiseptica transmission. Thus age-prevalence data, which is relatively easy to gather in clinical or agricultural settings, can be used to evaluate contact patterns and infer the likely age-cohort responsible for transmission of directly transmitted infections. These insights shed light on the dynamics of disease spread and allow an assessment to be made of the best methods for effective long-term disease control.

  11. Combination of IVF and IVM in naturally cycling women

    DEFF Research Database (Denmark)

    Tang-Pedersen, Mikael; Westergaard, Lars Grabow; Erb, Karin

    2012-01-01

    This study investigated the combination of an unstimulated IVF cycle with in-vitro maturation (IVM) of additional immature cumulus-oocyte-complexes (COC) from the same cycle collected at the same time as the spontaneous preovulatory follicle. This could potentially improve rates of embryo transfer...... and pregnancy/live births compared with conventional unstimulated IVF treatment and at the same time eliminate the risk of ovarian hyperstimulation syndrome. This prospective trial included 77 women with regular menstrual cycles. Age at inclusion was between 20 and 37 years. Results showed a retrieval rate...... between endometrial factors and IVM oocytes together with unknown competence of IVM embryos is suspected. For some time, there has been an increasing interest in mild approaches for fertility treatment, in particular IVF. In-vitro maturation (IVM) of immature eggs outside the ovaries followed by IVF...

  12. Guidelines for clockspeed acceleration in the US natural gas transmission industry

    International Nuclear Information System (INIS)

    Weijermars, Ruud

    2010-01-01

    This study presents the clockspeed analysis of a peer group comprising six major integrated US energy companies with substantial US interstate natural gas pipeline business activities: El Paso, Williams, NiSource, Kinder Morgan, MidAmerican and CMS Energy. For this peer group, the three clockspeed accelerators have been benchmarked at both corporate level and gas transmission business level, using time-series analysis and cross-sectional analysis over a 6-year period (2002-2007). The results are visualized in so-called clockspeed radargraphs. Overall corporate clockspeed winners - over the performance period studied - are: Williams, El Paso and Kinder Morgan; MidAmerican is a close follower. Corporate clockspeed laggards are: CMS Energy and NiSource. The peer group ranking for the natural gas transmission business segment shows similar clockspeed winners, but with different ranking in the following order: Kinder Morgan, MidAmerican and El Paso; Williams is a close follower. Clockspeed laggards for the natural gas transmission segments coincide with the corporate clockspeed laggards of the peer group: CMS Energy and NiSource (over the performance period studied); laggards of the past may become clockspeed leaders of the future if adjustments are made. Practical recommendations are formulated for achieving competitive clockspeed optimization in the US gas transmission industry as a whole. Recommendations for clockspeed acceleration at individual companies are also given. Although the US natural gas market is subject to specific regulations and its own geographical dynamics, this study also provides hints for improving the competitive clockspeed performance of gas transmission companies elsewhere, in other world regions. (author)

  13. Guidelines for clockspeed acceleration in the US natural gas transmission industry

    Energy Technology Data Exchange (ETDEWEB)

    Weijermars, Ruud [Department of Geotechnology, Delft University of Technology, PO Box 5048, 2600GA Delft (Netherlands)

    2010-08-15

    This study presents the clockspeed analysis of a peer group comprising six major integrated US energy companies with substantial US interstate natural gas pipeline business activities: El Paso, Williams, NiSource, Kinder Morgan, MidAmerican and CMS Energy. For this peer group, the three clockspeed accelerators have been benchmarked at both corporate level and gas transmission business level, using time-series analysis and cross-sectional analysis over a 6-year period (2002-2007). The results are visualized in so-called clockspeed radargraphs. Overall corporate clockspeed winners - over the performance period studied - are: Williams, El Paso and Kinder Morgan; MidAmerican is a close follower. Corporate clockspeed laggards are: CMS Energy and NiSource. The peer group ranking for the natural gas transmission business segment shows similar clockspeed winners, but with different ranking in the following order: Kinder Morgan, MidAmerican and El Paso; Williams is a close follower. Clockspeed laggards for the natural gas transmission segments coincide with the corporate clockspeed laggards of the peer group: CMS Energy and NiSource (over the performance period studied); laggards of the past may become clockspeed leaders of the future if adjustments are made. Practical recommendations are formulated for achieving competitive clockspeed optimization in the US gas transmission industry as a whole. Recommendations for clockspeed acceleration at individual companies are also given. Although the US natural gas market is subject to specific regulations and its own geographical dynamics, this study also provides hints for improving the competitive clockspeed performance of gas transmission companies elsewhere, in other world regions. (author)

  14. Towards better monitoring of technology critical elements in Europe: Coupling of natural and anthropogenic cycles.

    Science.gov (United States)

    Nuss, Philip; Blengini, Gian Andrea

    2018-02-01

    The characterization of elemental cycles has a rich history in biogeochemistry. Well known examples include the global carbon cycle, or the cycles of the 'grand nutrients' nitrogen, phosphorus, and sulfur. More recently, efforts have increased to better understand the natural cycling of technology critical elements (TCEs), i.e. elements with a high supply risk and economic importance in the EU. On the other hand, tools such as material-flow analysis (MFA) can help to understand how substances and goods are transported and accumulated in man-made technological systems ('anthroposphere'). However, to date both biogeochemical cycles and MFA studies suffer from narrow system boundaries, failing to fully illustrate relative anthropogenic and natural flow magnitude and the degree to which human activity has perturbed the natural cycling of elements. We discuss important interconnections between natural and anthropogenic cycles and relevant EU raw material dossiers. Increased integration of both cycles could help to better capture the transport and fate of elements in nature including their environmental/human health impacts, highlight potential future material stocks in the anthroposphere (in-use stocks) and in nature (e.g., in soils, tailings, or mining wastes), and estimate anticipated emissions of TCEs to nature in the future (based on dynamic stock modeling). A preliminary assessment of natural versus anthropogenic element fluxes indicates that anthropogenic fluxes induced by the EU-28 of palladium, platinum, and antimony (as a result of materials uses) might be greater than the respective global natural fluxes. Increased combination of MFA and natural cycle data at EU level could help to derive more complete material cycles and initiate a discussion between the research communities of biogeochemists and material flow analysts to more holistically address the issues of sustainable resource management. Copyright © 2017 The Authors. Published by Elsevier B.V. All

  15. Election cycles in natural resource rents : Empirical evidence

    NARCIS (Netherlands)

    Klomp, Jeroen; de Haan, Jakob

    We examine whether governments' natural resource rents are affected by upcoming elections and if so, whether the incumbent uses these additional rents for re-election purposes. Estimates of a dynamic panel model for about 60 countries for 1975-2011 suggest that elections increase natural resource

  16. Election cycles in natural resource rents: Empirical evidence

    NARCIS (Netherlands)

    Klomp, Jeroen; Haan, de Jakob

    2016-01-01

    We examine whether governments' natural resource rents are affected by upcoming elections and if so, whether the incumbent uses these additional rents for re-election purposes. Estimates of a dynamic panel model for about 60 countries for 1975-2011 suggest that elections increase natural resource

  17. Condensation in gas transmission pipelines. Phase behavior of mixtures of hydrogen with natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Schouten, J.A.; Michels, J.P.J. [Amsterdam Univ. (Netherlands). Van der Waals-Zeeman Inst.; Rosmalen, R.J. van [Energy, Roden (Netherlands)

    2005-05-01

    Several pressure and temperature reductions occur along gas transmission lines. Since the pressure and temperature conditions of the natural gas in the pipeline are often close to the dew point curve, liquid dropout can occur. Injection of hydrogen into the natural gas will change the phase envelope and thus the liquid dropout. This condensation of the heavy hydrocarbons requires continuous operational attention and a positive effect of hydrogen may affect the decision to introduce hydrogen. In this paper we report on calculations of the amount of condensate in a natural gas and in this natural gas mixed with 16.7% hydrogen. These calculations have been performed at conditions prevailing in gas transport lines. The results will be used to discuss the difference in liquid dropout in a natural gas and in a mixture with hydrogen at pressure reduction stations, at crossings under waterways, at side-branching, and at separators in the pipelines. (author)

  18. NATURAL GAS LIQUEFACTION UNITS ON THE BASE OF EXPANDER NITROGEN CYCLES

    OpenAIRE

    Кузьменко, И. Ф.; Передельский, В. А.; Довбиш, А. Л.

    2014-01-01

    It is necessary to create large-capacity LNG-units for natural gas peaks consumption shaving and also to expand liquefied natural gas (LNG) marketing. It is proposed to create such natural gas liquefaction units with the use of outer nitrogen cryogenic thermodynamic cycles. It is necessary to use turboexpander-compressor sets (TECS) in them for maximizing cycles efficiency. Different technological schemes of LNG-units including nitrogen cryogenic units with TECS from one to four have been exa...

  19. Study of cycle-by-cycle variations of a spark ignition engine fueled with natural gas-hydrogen blends

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jinhua; Chen, Hao; Liu, Bing; Huang, Zuohua [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2008-09-15

    Cycle-by-cycle variations of a spark ignition engine fueled with natural gas-hydrogen blends with hydrogen volumetric fraction of 0%, 12%, 23%, 30% and 40% were studied. The effect of hydrogen addition on cycle-by-cycle variations of the natural gas engine was analyzed. The results showed that the peak cylinder pressure, the maximum rate of pressure rise and the indicated mean effective pressure increased and their corresponding cycle-by-cycle variations decreased with the increase of hydrogen fraction at lean mixture operation. The interdependency between the combustion parameters and the corresponding crank angle tended to be strongly correlated with the increase of hydrogen fraction under lean mixture operation. Coefficient of variation of the indicated mean effective pressure gave a low level and is slightly influenced by hydrogen addition under the stoichiometric and relatively rich mixture operation while it decreased remarkably with the increase of hydrogen fraction under the lean mixture operation. The excessive air ratio at CoV{sub imep} = 10% extended to the leaner mixture side with the increase of hydrogen fraction and this indicated that the engine lean operating limit could be extended with hydrogen addition. (author)

  20. Daytime behavior of Pteropus vampyrus in a natural habitat: the driver of viral transmission

    OpenAIRE

    HENGJAN, Yupadee; PRAMONO, Didik; TAKEMAE, Hitoshi; KOBAYASHI, Ryosuke; IIDA, Keisuke; ANDO, Takeshi; KASMONO, Supratikno; BASRI, Chaerul; FITRIANA, Yuli Sulistya; ARIFIN, Eko M. Z.; OHMORI, Yasushige; MAEDA, Ken; AGUNGPRIYONO, Srihadi; HONDO, Eiichi

    2017-01-01

    Flying foxes, the genus Pteropus, are considered viral reservoirs. Their colonial nature and long flight capability enhance their ability to spread viruses quickly. To understand how the viral transmission occurs between flying foxes and other animals, we investigated daytime behavior of the large flying fox (Pteropus vampyrus) in the Leuweung Sancang conservation area, Indonesia, by using instantaneous scan sampling and all-occurrence focal sampling. The data were obtained from 0700 to 1700 ...

  1. Transmission efficiency of the sigma virus in natural populations of its host, Drosophila melanogaster.

    Science.gov (United States)

    Fleuriet, A

    1982-01-01

    A study of the viral samples collected in French natural populations of Drosophila melanogaster since 1969, indicates that natural populations include, as expected, both stabilized and non stabilized infected individuals. In agreement with previous observations made on other characters of the virus, the viral samples collected appear to be homogeneous for the efficiency of the hereditary transmission. However, this efficiency is greater than the average value observed with virus perpetuated in infected laboratory fly strains. One sample collected in Gabon and three in the U.S.A. appear to differ from the French samples for one at least of the traits studied in these experiments.

  2. Natural selection drives the evolution of ant life cycles.

    Science.gov (United States)

    Wilson, Edward O; Nowak, Martin A

    2014-09-02

    The genetic origin of advanced social organization has long been one of the outstanding problems of evolutionary biology. Here we present an analysis of the major steps in ant evolution, based for the first time, to our knowledge, on combined recent advances in paleontology, phylogeny, and the study of contemporary life histories. We provide evidence of the causal forces of natural selection shaping several key phenomena: (i) the relative lateness and rarity in geological time of the emergence of eusociality in ants and other animal phylads; (ii) the prevalence of monogamy at the time of evolutionary origin; and (iii) the female-biased sex allocation observed in many ant species. We argue that a clear understanding of the evolution of social insects can emerge if, in addition to relatedness-based arguments, we take into account key factors of natural history and study how natural selection acts on alleles that modify social behavior.

  3. Prediction of the diffuse-field transmission loss of interior natural-ventilation openings and silencers.

    Science.gov (United States)

    Bibby, Chris; Hodgson, Murray

    2017-01-01

    The work reported here, part of a study on the performance and optimal design of interior natural-ventilation openings and silencers ("ventilators"), discusses the prediction of the acoustical performance of such ventilators, and the factors that affect it. A wave-based numerical approach-the finite-element method (FEM)-is applied. The development of a FEM technique for the prediction of ventilator diffuse-field transmission loss is presented. Model convergence is studied with respect to mesh, frequency-sampling and diffuse-field convergence. The modeling technique is validated by way of predictions and the comparison of them to analytical and experimental results. The transmission-loss performance of crosstalk silencers of four shapes, and the factors that affect it, are predicted and discussed. Performance increases with flow-path length for all silencer types. Adding elbows significantly increases high-frequency transmission loss, but does not increase overall silencer performance which is controlled by low-to-mid-frequency transmission loss.

  4. First report of venereal and vertical transmission of canine leishmaniosis from naturally infected dogs in Germany

    Directory of Open Access Journals (Sweden)

    Naucke Torsten J

    2012-04-01

    Full Text Available Abstract Background Canine leishmaniosis (CanL is a zoonotic disease caused by Leishmania (L. infantum. It is endemic to several tropical and subtropical countries but also to the Mediterranean region. It is transmitted by phlebotomine sandflies but occasional non-vector transmissions have been reported, including vertical and horizontal transmission. Findings The authors report a case of CanL in a female boxer dog from Dusseldorf, Germany, that had never been in an endemic region. A serum sample from the bitch was tested positive for antibodies against Leishmania (IFAT 1:2,000, ELISA 72. The bitch had whelped three litters, and one puppy from the third litter was also found to be seropositive for Leishmania antibodies (IFAT 1:4,000, ELISA 78. Conclusions Up to now, despite intensive searching, the occurrence of sandflies could not be proved in the bitch's region of origin. Thus, vertical and horizontal transmission are to be discussed as possible ways of infection. This may be the first report of venereal and vertical transmission of L. infantum in naturally infected dogs in Germany.

  5. Data base for a CANDU-PHW operating on a once-through natural uranium cycle

    International Nuclear Information System (INIS)

    1979-07-01

    This report, prepared for INFCE, describes a standard 600 MW(e) CANDU-PHW reactor operating on a once-through natural uranium fuel cycle. Subsequently, data are given for an extrapolated 1000 MW(e) design (the nominal capacity adopted for the INFCE study) operating on the same fuel cycle. (author)

  6. Effectiveness of indometacin to prevent ovulation in modified natural-cycle IVF : A randomized controlled trial

    NARCIS (Netherlands)

    Rijken-Zijlstra, T. M.; Haadsma, M. L.; Hammer, C.; Burgerhof, J. G. M.; Pelinck, M. J.; Simons, A. H. M.; van Echten-Arends, J.; Arts, J. G. E. M.; Land, J. A.; Groen, H.; Hoek, A.

    Modified natural-cycle IVF has a lower pregnancy rate per started cycle as compared with IVF with ovarian stimulation due to, for example, premature ovulation. Indometacin administered before ovulation prevents follicle rupture. Therefore, addition of indometacin may improve the effectiveness of

  7. From Fall to Spring, or Spring to Fall? Seasonal Cholera Transmission Cycles and Implications for Climate Change

    Science.gov (United States)

    Akanda, A. S.; Jutla, A. S.; Huq, A.; Colwell, R.; Islam, S.; WE Reason

    2010-12-01

    Cholera remains a major public health threat in many developing countries around the world. The striking seasonality and the annual recurrence of this infectious disease in endemic areas continues to be of considerable interest to scientists and public health workers. Despite major advances in the ecological, and microbiological understanding of Vibrio cholerae, the causative agent, the role of underlying macro-scale hydroclimatic processes in propagating the disease in different seasons and years is not well understood. The incidence of cholera in the Bengal Delta region, the ‘native homeland’ of cholera, shows distinct biannual peaks in the southern floodplains, as opposed to single annual peaks in coastal areas and the northern parts of Bangladesh, as well as other cholera-endemic regions in the world. A coupled analysis of the regional hydroclimate and cholera incidence reveals a strong association of the spatio-temporal variability of incidence peaks with seasonal processes and extreme events. At a seasonal scale, the cycles indicate a spring-fall transmission pattern, contrary to the prevalent notion of a fall-spring transmission cycle. We show that the asymmetric seasonal hydroclimatology affects regional cholera dynamics by providing a coastal growth environment for bacteria in spring, while propagating transmission to fall by flooding. This seasonal interpretation of the progression of cholera has important implications, for formulating effective cholera intervention and mitigation efforts through improved water management and understanding the impacts of changing climate patterns on seasonal cholera transmission. (Water Environental Research Education Actionable Solutions Network)

  8. Integrating Natural Gas Hydrates in the Global Carbon Cycle

    Energy Technology Data Exchange (ETDEWEB)

    David Archer; Bruce Buffett

    2011-12-31

    We produced a two-dimensional geological time- and basin-scale model of the sedimentary margin in passive and active settings, for the simulation of the deep sedimentary methane cycle including hydrate formation. Simulation of geochemical data required development of parameterizations for bubble transport in the sediment column, and for the impact of the heterogeneity in the sediment pore fluid flow field, which represent new directions in modeling methane hydrates. The model is somewhat less sensitive to changes in ocean temperature than our previous 1-D model, due to the different methane transport mechanisms in the two codes (pore fluid flow vs. bubble migration). The model is very sensitive to reasonable changes in organic carbon deposition through geologic time, and to details of how the bubbles migrate, in particular how efficiently they are trapped as they rise through undersaturated or oxidizing chemical conditions and the hydrate stability zone. The active margin configuration reproduces the elevated hydrate saturations observed in accretionary wedges such as the Cascadia Margin, but predicts a decrease in the methane inventory per meter of coastline relative to a comparable passive margin case, and a decrease in the hydrate inventory with an increase in the plate subduction rate.

  9. Natural gas transmission and distribution model of the National Energy Modeling System

    International Nuclear Information System (INIS)

    1997-02-01

    The Natural Gas Transmission and Distribution Model (NGTDM) is the component of the National Energy Modeling System (NEMS) that is used to represent the domestic natural gas transmission and distribution system. NEMS was developed in the Office of Integrated Analysis and Forecasting of the Energy Information Administration (EIA). NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the EIA and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. From 1982 through 1993, the Intermediate Future Forecasting System (IFFS) was used by the EIA for its analyses, and the Gas Analysis Modeling System (GAMS) was used within IFFS to represent natural gas markets. Prior to 1982, the Midterm Energy Forecasting System (MEFS), also referred to as the Project Independence Evaluation System (PIES), was employed. NEMS was developed to enhance and update EIA's modeling capability by internally incorporating models of energy markets that had previously been analyzed off-line. In addition, greater structural detail in NEMS permits the analysis of a broader range of energy issues. The time horizon of NEMS is the midterm period (i.e., through 2015). In order to represent the regional differences in energy markets, the component models of NEMS function at regional levels appropriate for the markets represented, with subsequent aggregation/disaggregation to the Census Division level for reporting purposes

  10. Natural gas transmission and distribution model of the National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The Natural Gas Transmission and Distribution Model (NGTDM) is the component of the National Energy Modeling System (NEMS) that is used to represent the domestic natural gas transmission and distribution system. NEMS was developed in the Office of Integrated Analysis and Forecasting of the Energy Information Administration (EIA). NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the EIA and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. From 1982 through 1993, the Intermediate Future Forecasting System (IFFS) was used by the EIA for its analyses, and the Gas Analysis Modeling System (GAMS) was used within IFFS to represent natural gas markets. Prior to 1982, the Midterm Energy Forecasting System (MEFS), also referred to as the Project Independence Evaluation System (PIES), was employed. NEMS was developed to enhance and update EIA`s modeling capability by internally incorporating models of energy markets that had previously been analyzed off-line. In addition, greater structural detail in NEMS permits the analysis of a broader range of energy issues. The time horizon of NEMS is the midterm period (i.e., through 2015). In order to represent the regional differences in energy markets, the component models of NEMS function at regional levels appropriate for the markets represented, with subsequent aggregation/disaggregation to the Census Division level for reporting purposes.

  11. Nonlinear dynamics of cycle-to-cycle combustion variations in a lean-burn natural gas engine

    International Nuclear Information System (INIS)

    Li Guoxiu; Yao Baofeng

    2008-01-01

    Temporal dynamics of the combustion process in a lean-burn natural gas engine was studied by the analysis of time series of consecutive experimental in-cylinder pressure data in this work. Methods borrowed to the nonlinear dynamical system theory were applied to analyze the in-cylinder pressure time series under operating conditions with different equivalence ratio. Phase spaces were reconstructed from the in-cylinder pressure time series and Poincare section calculated from each phase space. Poincare sections show that the in-cylinder combustion process involves chaotic behavior. Furthermore, return maps plotted from time series of indicated mean effective pressure show that both nonlinear deterministic components and stochastic components are involved in the dynamics of cycle-to-cycle combustion variations in the lean burn natural gas engine. There is a transition from stochastic behavior to noisy nonlinear determinism as equivalence ratio decreases from near stoichiometric to very lean conditions

  12. Nonlinear dynamics of cycle-to-cycle combustion variations in a lean-burn natural gas engine

    Energy Technology Data Exchange (ETDEWEB)

    Li Guoxiu [School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China)], E-mail: gxli@bjtu.edu.cn; Yao Baofeng [School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China)

    2008-04-15

    Temporal dynamics of the combustion process in a lean-burn natural gas engine was studied by the analysis of time series of consecutive experimental in-cylinder pressure data in this work. Methods borrowed to the nonlinear dynamical system theory were applied to analyze the in-cylinder pressure time series under operating conditions with different equivalence ratio. Phase spaces were reconstructed from the in-cylinder pressure time series and Poincare section calculated from each phase space. Poincare sections show that the in-cylinder combustion process involves chaotic behavior. Furthermore, return maps plotted from time series of indicated mean effective pressure show that both nonlinear deterministic components and stochastic components are involved in the dynamics of cycle-to-cycle combustion variations in the lean burn natural gas engine. There is a transition from stochastic behavior to noisy nonlinear determinism as equivalence ratio decreases from near stoichiometric to very lean conditions.

  13. Mitigation of Prion Infectivity and Conversion Capacity by a Simulated Natural Process—Repeated Cycles of Drying and Wetting

    Science.gov (United States)

    Yuan, Qi; Eckland, Thomas; Telling, Glenn; Bartz, Jason; Bartelt-Hunt, Shannon

    2015-01-01

    Prions enter the environment from infected hosts, bind to a wide range of soil and soil minerals, and remain highly infectious. Environmental sources of prions almost certainly contribute to the transmission of chronic wasting disease in cervids and scrapie in sheep and goats. While much is known about the introduction of prions into the environment and their interaction with soil, relatively little is known about prion degradation and inactivation by natural environmental processes. In this study, we examined the effect of repeated cycles of drying and wetting on prion fitness and determined that 10 cycles of repeated drying and wetting could reduce PrPSc abundance, PMCA amplification efficiency and extend the incubation period of disease. Importantly, prions bound to soil were more susceptible to inactivation by repeated cycles of drying and wetting compared to unbound prions, a result which may be due to conformational changes in soil-bound PrPSc or consolidation of the bonding between PrPSc and soil. This novel finding demonstrates that naturally-occurring environmental process can degrade prions. PMID:25665187

  14. Use of 15N Natural Abundance and N Species Concentrations to Assess N-Cycling in Constructed and Natural Coastal

    International Nuclear Information System (INIS)

    Aelion, W.C.M.; Engle, M.R.; Aelion, W.C.M.; Ma, H.

    2010-01-01

    Natural abundance of N stable isotopes used in combination with concentrations may be useful indicators of N-cycling in wetlands. Concentrations and 15 N signatures of NO 3 -, NH 4 and sediment organic nitrogen (SON) were measured in two impacted coastal golf course retention ponds and two natural marshes. Limited NO 3 was detected in natural site surface water or pore water, but both isotopic signature and concentrations of NO 3 - in surface water of impacted sites indicated anthropogenic inputs. In natural sites, NH 4 concentrations were greatest in deeper pore water and least in surface water, suggesting diffusion predominates. The natural sites had greater % SON, and 15 N indicated that the natural sites also had greater NH 4 + released from SON mineralization than impacted sites. In NO 3 --limited systems, neither concentrations nor 15 N natural abundance was able to provide information on N-cycling, while processes associated with NH 4 + were better elucidated by using both concentrations and 15 N natural abundance

  15. Use of N Natural Abundance and N Species Concentrations to Assess N-Cycling in Constructed and Natural Coastal Wetlands

    Directory of Open Access Journals (Sweden)

    C. Marjorie Aelion

    2010-01-01

    Full Text Available Natural abundance of N stable isotopes used in combination with concentrations may be useful indicators of N-cycling in wetlands. Concentrations and N signatures of NO3−, NH4+, and sediment organic nitrogen (SON were measured in two impacted coastal golf course retention ponds and two natural marshes. Limited NO3− was detected in natural site surface water or pore water, but both isotopic signature and concentrations of NO3− in surface water of impacted sites indicated anthropogenic inputs. In natural sites, NH4+ concentrations were greatest in deeper pore water and least in surface water, suggesting diffusion predominates. The natural sites had greater %SON, and N indicated that the natural sites also had greater NH4+ released from SON mineralization than impacted sites. In NO3−-limited systems, neither concentrations nor N natural abundance was able to provide information on N-cycling, while processes associated with NH4+ were better elucidated by using both concentrations and N natural abundance.

  16. Natural vertical transmission of dengue viruses by Aedes aegypti in Bolivia

    Science.gov (United States)

    Le Goff, G.; Revollo, J.; Guerra, M.; Cruz, M.; Barja Simon, Z.; Roca, Y.; Vargas Florès, J.; Hervé, J.P.

    2011-01-01

    The natural transmission of dengue virus from an infected female mosquito to its progeny, namely the vertical transmission, was researched in wild caught Aedes aegypti during an important outbreak in the town of Santa Cruz de la Sierra, Bolivia. Mosquitoes were collected at the preimaginal stages (eggs, larvae and pupae) then reared up to adult stage for viral detection using molecular methods. Dengue virus serotypes 1 and 3 were found to be co-circulating with significant higher prevalence in male than in female mosquitoes. Of the 97 pools of Ae. aegypti (n = 635 male and 748 female specimens) screened, 14 pools, collected in February-May in 2007, were found positive for dengue virus infection: five DEN-1 and nine DEN-3. The average true infection rate (TIR) and minimum infection rate (MIR) were respectively 1.08% and 1.01%. These observations suggest that vertical transmission of dengue virus may be detected in vectors at the peak of an outbreak as well as several months before an epidemic occurs in human population. PMID:21894270

  17. Daytime behavior of Pteropus vampyrus in a natural habitat: the driver of viral transmission.

    Science.gov (United States)

    Hengjan, Yupadee; Pramono, Didik; Takemae, Hitoshi; Kobayashi, Ryosuke; Iida, Keisuke; Ando, Takeshi; Kasmono, Supratikno; Basri, Chaerul; Fitriana, Yuli Sulistya; Arifin, Eko M Z; Ohmori, Yasushige; Maeda, Ken; Agungpriyono, Srihadi; Hondo, Eiichi

    2017-06-29

    Flying foxes, the genus Pteropus, are considered viral reservoirs. Their colonial nature and long flight capability enhance their ability to spread viruses quickly. To understand how the viral transmission occurs between flying foxes and other animals, we investigated daytime behavior of the large flying fox (Pteropus vampyrus) in the Leuweung Sancang conservation area, Indonesia, by using instantaneous scan sampling and all-occurrence focal sampling. The data were obtained from 0700 to 1700 hr, during May 11-25, 2016. Almost half of the flying foxes (46.9 ± 10.6% of all recorded bats) were awake and showed various levels of activity during daytime. The potential behaviors driving disease transmission, such as self-grooming, mating/courtship and aggression, peaked in the early morning. Males were more active and spent more time on sexual activities than females. There was no significant difference in time spent for negative social behaviors between sexes. Positive social behaviors, especially maternal cares, were performed only by females. Sexual activities and negative/positive social behaviors enable fluid exchange between bats and thus facilitate intraspecies transmission. Conflicts for living space between the flying foxes and the ebony leaf monkey (Trachypithecus auratus) were observed, and this caused daily roosting shifts of flying foxes. The ecological interactions between bats and other wildlife increase the risk of interspecies infection. This study provides the details of the flying fox's behavior and its interaction with other wildlife in South-East Asia that may help explain how pathogen spillover occurs in the wild.

  18. Combined Brayton-JT cycles with refrigerants for natural gas liquefaction

    Science.gov (United States)

    Chang, Ho-Myung; Park, Jae Hoon; Lee, Sanggyu; Choe, Kun Hyung

    2012-06-01

    Thermodynamic cycles for natural gas liquefaction with single-component refrigerants are investigated under a governmental project in Korea, aiming at new processes to meet the requirements on high efficiency, large capacity, and simple equipment. Based upon the optimization theory recently published by the present authors, it is proposed to replace the methane-JT cycle in conventional cascade process with a nitrogen-Brayton cycle. A variety of systems to combine nitrogen-Brayton, ethane-JT and propane-JT cycles are simulated with Aspen HYSYS and quantitatively compared in terms of thermodynamic efficiency, flow rate of refrigerants, and estimated size of heat exchangers. A specific Brayton-JT cycle is suggested with detailed thermodynamic data for further process development. The suggested cycle is expected to be more efficient and simpler than the existing cascade process, while still taking advantage of easy and robust operation with single-component refrigerants.

  19. Pollutant Dispersion Modeling in Natural Streams Using the Transmission Line Matrix Method

    Directory of Open Access Journals (Sweden)

    Safia Meddah

    2015-09-01

    Full Text Available Numerical modeling has become an indispensable tool for solving various physical problems. In this context, we present a model of pollutant dispersion in natural streams for the far field case where dispersion is considered longitudinal and one-dimensional in the flow direction. The Transmission Line Matrix (TLM, which has earned a reputation as powerful and efficient numerical method, is used. The presented one-dimensional TLM model requires a minimum input data and provides a significant gain in computing time. To validate our model, the results are compared with observations and experimental data from the river Severn (UK. The results show a good agreement with experimental data. The model can be used to predict the spatiotemporal evolution of a pollutant in natural streams for effective and rapid decision-making in a case of emergency, such as accidental discharges in a stream with a dynamic similar to that of the river Severn (UK.

  20. Model documentation Natural Gas Transmission and Distribution Model of the National Energy Modeling System. Volume 1

    International Nuclear Information System (INIS)

    1996-01-01

    The Natural Gas Transmission and Distribution Model (NGTDM) of the National Energy Modeling System is developed and maintained by the Energy Information Administration (EIA), Office of Integrated Analysis and Forecasting. This report documents the archived version of the NGTDM that was used to produce the natural gas forecasts presented in the Annual Energy Outlook 1996, (DOE/EIA-0383(96)). The purpose of this report is to provide a reference document for model analysts, users, and the public that defines the objectives of the model, describes its basic approach, and provides detail on the methodology employed. Previously this report represented Volume I of a two-volume set. Volume II reported on model performance, detailing convergence criteria and properties, results of sensitivity testing, comparison of model outputs with the literature and/or other model results, and major unresolved issues

  1. Model documentation Natural Gas Transmission and Distribution Model of the National Energy Modeling System. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-26

    The Natural Gas Transmission and Distribution Model (NGTDM) of the National Energy Modeling System is developed and maintained by the Energy Information Administration (EIA), Office of Integrated Analysis and Forecasting. This report documents the archived version of the NGTDM that was used to produce the natural gas forecasts presented in the Annual Energy Outlook 1996, (DOE/EIA-0383(96)). The purpose of this report is to provide a reference document for model analysts, users, and the public that defines the objectives of the model, describes its basic approach, and provides detail on the methodology employed. Previously this report represented Volume I of a two-volume set. Volume II reported on model performance, detailing convergence criteria and properties, results of sensitivity testing, comparison of model outputs with the literature and/or other model results, and major unresolved issues.

  2. Environmental impact analysis of batik natural dyes using life cycle assessment

    Science.gov (United States)

    Rinawati, Dyah Ika; Sari, Diana Puspita; Purwanggono, Bambang; Hermawan, Andy Tri

    2017-11-01

    The use of natural dyes for batik dyeing is fewer than synthetic dyes because of its limitations in the application such complexity in manufacture and usage. For ease of use, natural dyes need to be processed into instant products. Extract of natural dyes are generally produced in liquid form that are less practical in long-term use. Dye powder obtained by drying the liquid extract using spray dryer. Production process of liquid natural dye is simpler and require less energy but need more energy for transporting. It is important to know which type of natural dyes should be produced based on their environmental impact. This research aim to compare environmental impact between liquid and powder natural dyes and also to find relative contribution of different stage in life cycle to total environmental impact. The appropriate method to analyze and compare the environmental impacts of powder and liquid natural dyes is Life Cycle Assessment (LCA). The "cradle to grave" approach used to assess environmental impact of powder and liquid natural dyes of Jalawe rind throughout production process of natural dyes, distribution and use of natural dyes for coloring batik. Results of this research show that powder natural dyes has lower environmental impacts than liquid natural dyes. It was found that distribution, mordanting and packaging of liquid dyes have big contribution to environmental impact.

  3. Nature, Nurture and Evolution of Intra-Species Variation in Mosquito Arbovirus Transmission Competence

    Directory of Open Access Journals (Sweden)

    Walter J. Tabachnick

    2013-01-01

    Full Text Available Mosquitoes vary in their competence or ability to transmit arthropod-borne viruses (arboviruses. Many arboviruses cause disease in humans and animals. Identifying the environmental and genetic causes of variation in mosquito competence for arboviruses is one of the great challenges in public health. Progress identifying genetic (nature and environmental (nurture factors influencing mosquito competence for arboviruses is reviewed. There is great complexity in the various traits that comprise mosquito competence. The complex interactions between environmental and genetic factors controlling these traits and the factors shaping variation in Nature are largely unknown. The norms of reaction of specific genes influencing competence, their distributions in natural populations and the effects of genetic polymorphism on phenotypic variation need to be determined. Mechanisms influencing competence are not likely due to natural selection because of the direct effects of the arbovirus on mosquito fitness. More likely the traits for mosquito competence for arboviruses are the effects of adaptations for other functions of these competence mechanisms. Determining these other functions is essential to understand the evolution and distributions of competence for arboviruses. This information is needed to assess risk from mosquito-borne disease, predict new mosquito-arbovirus systems, and provide novel strategies to mitigate mosquito-borne arbovirus transmission.

  4. Nature, Nurture and Evolution of Intra-Species Variation in Mosquito Arbovirus Transmission Competence

    Science.gov (United States)

    Tabachnick, Walter J.

    2013-01-01

    Mosquitoes vary in their competence or ability to transmit arthropod-borne viruses (arboviruses). Many arboviruses cause disease in humans and animals. Identifying the environmental and genetic causes of variation in mosquito competence for arboviruses is one of the great challenges in public health. Progress identifying genetic (nature) and environmental (nurture) factors influencing mosquito competence for arboviruses is reviewed. There is great complexity in the various traits that comprise mosquito competence. The complex interactions between environmental and genetic factors controlling these traits and the factors shaping variation in Nature are largely unknown. The norms of reaction of specific genes influencing competence, their distributions in natural populations and the effects of genetic polymorphism on phenotypic variation need to be determined. Mechanisms influencing competence are not likely due to natural selection because of the direct effects of the arbovirus on mosquito fitness. More likely the traits for mosquito competence for arboviruses are the effects of adaptations for other functions of these competence mechanisms. Determining these other functions is essential to understand the evolution and distributions of competence for arboviruses. This information is needed to assess risk from mosquito-borne disease, predict new mosquito-arbovirus systems, and provide novel strategies to mitigate mosquito-borne arbovirus transmission. PMID:23343982

  5. Nature, nurture and evolution of intra-species variation in mosquito arbovirus transmission competence.

    Science.gov (United States)

    Tabachnick, Walter J

    2013-01-11

    Mosquitoes vary in their competence or ability to transmit arthropod-borne viruses (arboviruses). Many arboviruses cause disease in humans and animals. Identifying the environmental and genetic causes of variation in mosquito competence for arboviruses is one of the great challenges in public health. Progress identifying genetic (nature) and environmental (nurture) factors influencing mosquito competence for arboviruses is reviewed. There is great complexity in the various traits that comprise mosquito competence. The complex interactions between environmental and genetic factors controlling these traits and the factors shaping variation in Nature are largely unknown. The norms of reaction of specific genes influencing competence, their distributions in natural populations and the effects of genetic polymorphism on phenotypic variation need to be determined. Mechanisms influencing competence are not likely due to natural selection because of the direct effects of the arbovirus on mosquito fitness. More likely the traits for mosquito competence for arboviruses are the effects of adaptations for other functions of these competence mechanisms. Determining these other functions is essential to understand the evolution and distributions of competence for arboviruses. This information is needed to assess risk from mosquito-borne disease, predict new mosquito-arbovirus systems, and provide novel strategies to mitigate mosquito-borne arbovirus transmission.

  6. Illumination of murine gammaherpesvirus-68 cycle reveals a sexual transmission route from females to males in laboratory mice.

    Directory of Open Access Journals (Sweden)

    Sylvie François

    Full Text Available Transmission is a matter of life or death for pathogen lineages and can therefore be considered as the main motor of their evolution. Gammaherpesviruses are archetypal pathogenic persistent viruses which have evolved to be transmitted in presence of specific immune response. Identifying their mode of transmission and their mechanisms of immune evasion is therefore essential to develop prophylactic and therapeutic strategies against these infections. As the known human gammaherpesviruses, Epstein-Barr virus and Kaposi's Sarcoma-associated Herpesvirus are host-specific and lack a convenient in vivo infection model; related animal gammaherpesviruses, such as murine gammaherpesvirus-68 (MHV-68, are commonly used as general models of gammaherpesvirus infections in vivo. To date, it has however never been possible to monitor viral excretion or virus transmission of MHV-68 in laboratory mice population. In this study, we have used MHV-68 associated with global luciferase imaging to investigate potential excretion sites of this virus in laboratory mice. This allowed us to identify a genital excretion site of MHV-68 following intranasal infection and latency establishment in female mice. This excretion occurred at the external border of the vagina and was dependent on the presence of estrogens. However, MHV-68 vaginal excretion was not associated with vertical transmission to the litter or with horizontal transmission to female mice. In contrast, we observed efficient virus transmission to naïve males after sexual contact. In vivo imaging allowed us to show that MHV-68 firstly replicated in penis epithelium and corpus cavernosum before spreading to draining lymph nodes and spleen. All together, those results revealed the first experimental transmission model for MHV-68 in laboratory mice. In the future, this model could help us to better understand the biology of gammaherpesviruses and could also allow the development of strategies that could prevent

  7. Model documentation: Natural Gas Transmission and Distribution Model of the National Energy Modeling System; Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-02-24

    The Natural Gas Transmission and Distribution Model (NGTDM) is a component of the National Energy Modeling System (NEMS) used to represent the domestic natural gas transmission and distribution system. NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the Energy Information Administration (EIA) and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. This report documents the archived version of NGTDM that was used to produce the natural gas forecasts used in support of the Annual Energy Outlook 1994, DOE/EIA-0383(94). The purpose of this report is to provide a reference document for model analysts, users, and the public that defines the objectives of the model, describes its basic design, provides detail on the methodology employed, and describes the model inputs, outputs, and key assumptions. It is intended to fulfill the legal obligation of the EIA to provide adequate documentation in support of its models (Public Law 94-385, Section 57.b.2). This report represents Volume 1 of a two-volume set. (Volume 2 will report on model performance, detailing convergence criteria and properties, results of sensitivity testing, comparison of model outputs with the literature and/or other model results, and major unresolved issues.) Subsequent chapters of this report provide: (1) an overview of the NGTDM (Chapter 2); (2) a description of the interface between the National Energy Modeling System (NEMS) and the NGTDM (Chapter 3); (3) an overview of the solution methodology of the NGTDM (Chapter 4); (4) the solution methodology for the Annual Flow Module (Chapter 5); (5) the solution methodology for the Distributor Tariff Module (Chapter 6); (6) the solution methodology for the Capacity Expansion Module (Chapter 7); (7) the solution methodology for the Pipeline Tariff Module (Chapter 8); and (8) a description of model assumptions, inputs, and outputs (Chapter 9).

  8. Country-Level Life Cycle Assessment of Greenhouse Gas Emissions from Liquefied Natural Gas Trade for Electricity Generation.

    Science.gov (United States)

    Kasumu, Adebola S; Li, Vivian; Coleman, James W; Liendo, Jeanne; Jordaan, Sarah M

    2018-02-20

    In the determination of the net impact of liquefied natural gas (LNG) on greenhouse gas emissions, life cycle assessments (LCA) of electricity generation have yet to combine the effects of transport distances between exporting and importing countries, country-level infrastructure in importing countries, and the fuel sources displaced in importing countries. To address this, we conduct a LCA of electricity generated from LNG export from British Columbia, Canada with a three-step approach: (1) a review of viable electricity generation markets for LNG, (2) the development of results for greenhouse gas emissions that account for transport to importing nations as well as the infrastructure required for power generation and delivery, and (3) emissions displacement scenarios to test assumptions about what electricity is being displaced in the importing nation. Results show that while the ultimate magnitude of the greenhouse gas emissions associated with natural gas production systems is still unknown, life cycle greenhouse gas emissions depend on country-level infrastructure (specifically, the efficiency of the generation fleet, transmission and distribution losses and LNG ocean transport distances) as well as the assumptions on what is displaced in the domestic electricity generation mix. Exogenous events such as the Fukushima nuclear disaster have unanticipated effects on the emissions displacement results. We highlight national regulations, environmental policies, and multilateral agreements that could play a role in mitigating emissions.

  9. A precipitation-induced landslide susceptibility model for natural gas transmission pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Finley, Jason P. [Fugro William Lettis and Associates, Inc., Valencia, California (United States); Slayter, David L.; Hitchcock, Chris S. [Fugro William Lettis and Associates, Inc., Walnut Creek, California (United States); Lee, Chih-Hung [Pacific Gas and Electric Company, Gas Systems Integrity Management, Walnut Creek, California (United States)

    2010-07-01

    Landslides related to heavy rainfall can cause extensive damage to natural gas transmission pipelines. Fugro William Lettis and Associates Inc. have developed and implemented a geographic information system (GIS) model that evaluates near real-time precipitation-induced landslide susceptibility. The model incorporates state-wide precipitation data and geologically-based landslide classifications to produce rapid landslide risk evaluation for Pacific Gas and Electric Company's (PGandE) gas transmission system during winter rain storms in California. The precipitation data include pre-storm event quantitative precipitation forecasts (QPF) and post-storm event quantitative precipitation estimate (QPE) from the United States National Oceanic and Atmospheric Administration (NOAA). The geologic classifications are based on slope, susceptible geologic formations, and the locations of historic or known landslide occurrences. Currently the model is calibrated using qualitative measures. This paper describes the development of the model algorithm and input data, model results, calibration efforts, and the on-going research and landslide collection warranted for continued refinement of the model.

  10. Modeling of leak detection system for high pressure transmission system of natural gas

    International Nuclear Information System (INIS)

    Qureshi, S.A.; Paracha, Z.J.; Ali, A.

    2005-01-01

    Gas Industry can be considered as one of the most important industries in the economy of any country. Safe Transportation of Gas is thus considered to be vital because interruption of Supply of Gas to consumers not only causes domestic problems but also loss of revenue to country. Now most of power generation Sector has switched over their system to Natural Gas. So, interruption of supply to this sector can cause a lot of problems. This paper has provided assessment of technology approach and formulated this approach for Leak Detection Model in High Pressure Transmission system for current and future operations, which will improve the efficiency of any transmission company to a great extent. This model can be extremely helpful in conditions of Rupture Emergencies or Leakage because of corrosive conditions of Pipeline to manage the situation of resources in pipeline network. Any exceptional readings or messages should alert the user to the fact that something is wrong with the system. Such a system helps a lot in the safe and efficient management of pipeline network. The data and information provided by the Leak Detection System applications will allow for efficient and safe pipeline operation maximizing profitability over the pipeline's service lifetime. (author)

  11. Rethinking the area of protection "natural resources" in life cycle assessment.

    Science.gov (United States)

    Dewulf, Jo; Benini, Lorenzo; Mancini, Lucia; Sala, Serenella; Blengini, Gian Andrea; Ardente, Fulvio; Recchioni, Marco; Maes, Joachim; Pant, Rana; Pennington, David

    2015-05-05

    Life cycle impact assessment (LCIA) in classical life cycle assessment (LCA) aims at analyzing potential impacts of products and services typically on three so-called areas of protection (AoPs): Natural Environment, Human Health, and Natural Resources. This paper proposes an elaboration of the AoP Natural Resources. It starts with analyzing different perspectives on Natural Resources as they are somehow sandwiched in between the Natural Environment (their cradle) and the human-industrial environment (their application). Reflecting different viewpoints, five perspectives are developed with the suggestion to select three in function of classical LCA. They result in three safeguard subjects: the Asset of Natural Resources, their Provisioning Capacity, and their role in Global Functions. Whereas the Provisioning Capacity is fully in function of humans, the global functions go beyond provisioning as they include nonprovisioning functions for humans and regulating and maintenance services for the globe as a whole, following the ecosystem services framework. A fourth and fifth safeguard subject has been identified: recognizing the role Natural Resources for human welfare, either specifically as building block in supply chains of products and services as such, either with or without their functions beyond provisioning. But as these are far broader as they in principle should include characterization of mechanisms within the human industrial society, they are considered as subjects for an integrated sustainability assessment (LCSA: life cycle sustainability assessment), that is, incorporating social, economic and environmental issues.

  12. Human chorionic gonadotropin-administered natural cycle versus spontaneous ovulatory cycle in patients undergoing two pronuclear zygote frozen-thawed embryo transfer.

    Science.gov (United States)

    Lee, You-Jung; Kim, Chung-Hoon; Kim, Do-Young; Ahn, Jun-Woo; Kim, Sung-Hoon; Chae, Hee-Dong; Kang, Byung-Moon

    2018-03-01

    To compare human chorionic gonadotropin (HCG)-administered natural cycle with spontaneous ovulatory cycle in patients undergoing frozen-thawed embryo transfer (FTET) in natural cycles. In this retrospective cohort study, we analyzed the clinical outcome of a total of 166 consecutive FTET cycles that were performed in either natural cycle controlled by HCG for ovulation triggering (HCG group, n=110) or natural cycle with spontaneous ovulation (control group, n=56) in 166 infertile patients between January 2009 and November 2013. There were no differences in patients' characteristics between the 2 groups. The numbers of oocytes retrieved, mature oocytes, fertilized oocytes, grade I or II embryos and frozen embryos in the previous in vitro fertilization (IVF) cycle in which embryos were frozen were comparable between the HCG and control groups. Significant differences were not also observed between the 2 groups in clinical pregnancy rate (CPR), embryo implantation rate, miscarriage rate, live birth rate and multiple CPR. However, the number of hospital visits for follicular monitoring was significantly fewer in the HCG group than in the control group ( P cycle reduces the number of hospital visits for follicular monitoring without any detrimental effect on FTET outcome when compared with spontaneous ovulatory cycles in infertile patients undergoing FTET in natural ovulatory cycles.

  13. Analysis and design of Fuel Cycle Plant for natural phenomena hazards

    International Nuclear Information System (INIS)

    Horsager, B.K.

    1985-01-01

    A description of the Design Basis and the analysis and design methods used for natural phenomena at the Fuel Cycle Plant at Hanford, Washington is presented. A physical description of the main process facility and the auxiliary emergency and support facilities is given. The mission of the facility is presented and a brief description of the processes which will take place within the facility is given. The Design Criteria and design bases for natural phenomena including tornados, earthquakes and volcanic eruptions are described

  14. Soils Alive! From Tiny Rocks to Composting. Cycling Back to Nature.

    Science.gov (United States)

    Horton, Robert L.; And Others

    This environmental sourcebook contains activities focusing on the living and nonliving components of soil and their relationship to the earth's natural cycles. The materials contained in this guide are for use with youth ages ten and older and are designed to stimulate a sense of stewardship for the environment through group discussion, role…

  15. Life Cycle Assessment of Hydrogen Production via Natural Gas Steam Reforming; TOPICAL

    International Nuclear Information System (INIS)

    Spath, P. L.; Mann, M. K.

    2000-01-01

    A life cycle assessment of hydrogen production via natural gas steam reforming was performed to examine the net emissions of greenhouse gases as well as other major environmental consequences. LCA is a systematic analytical method that helps identify and evaluate the environmental impacts of a specific process or competing processes

  16. The relationship between natural uranium and advanced fuel cycles in CANDU reactors

    International Nuclear Information System (INIS)

    Lane, A.D.; McDonnell, F.N.; Griffiths, J.

    1988-11-01

    CANDU is the most uranium-economic type of thermal power reactor, and is the only type used in Canada. CANDU reactors consume approximately 15% of Canadian uranium production and support a fuel service industry valued at ∼$250 M/a. In addition to their once-through, natural-uranium fuel cycle, CANDU reactors are capable of operating with slightly-enriched uranium (SEU), uranium-plutonium and thorium cycles, more efficiently than other reactors. Only SEU is economically attractive in Canada now, but the other cycles are of interest to countries without indigenous fuel resources. A program is underway to establish the fuel technologies necessary for the use of SEU and the other fuel cycles in CANDU reactors. 22 refs

  17. Natural ventilation reduces high TB transmission risk in traditional homes in rural KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Lygizos, Melissa; Shenoi, Sheela V; Brooks, Ralph P; Bhushan, Ambika; Brust, James C M; Zelterman, Daniel; Deng, Yanhong; Northrup, Veronika; Moll, Anthony P; Friedland, Gerald H

    2013-07-01

    Transmission of drug susceptible and drug resistant TB occurs in health care facilities, and community and households settings, particularly in highly prevalent TB and HIV areas. There is a paucity of data regarding factors that may affect TB transmission risk in household settings. We evaluated air exchange and the impact of natural ventilation on estimated TB transmission risk in traditional Zulu homes in rural South Africa. We utilized a carbon dioxide decay technique to measure ventilation in air changes per hour (ACH). We evaluated predominant home types to determine factors affecting ACH and used the Wells-Riley equation to estimate TB transmission risk. Two hundred eighteen ventilation measurements were taken in 24 traditional homes. All had low ventilation at baseline when windows were closed (mean ACH = 3, SD = 3.0), with estimated TB transmission risk of 55.4% over a ten hour period of exposure to an infectious TB patient. There was significant improvement with opening windows and door, reaching a mean ACH of 20 (SD = 13.1, p ventilation conditions (windows/doors open) and window to volume ratio. Expanding ventilation increased the odds of achieving ≥12 ACH by 60-fold. There is high estimated risk of TB transmission in traditional homes of infectious TB patients in rural South Africa. Improving natural ventilation may decrease household TB transmission risk and, combined with other strategies, may enhance TB control efforts.

  18. Scanning transmission X-ray microscopy as a speciation tool for natural organic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Rothe, J.; Plaschke, M.; Denecke, M.A. [Inst. fuer Nukleare Entsorgung, Forschungszentrum Karlsruhe, Karlsruhe (Germany)

    2004-07-01

    A molecular-scale understanding of the basic processes affecting stability and transport behavior of actinide cations, complexes or hydroxide ('eigencolloid') species is prerequisite to performance assessment of nuclear waste disposal in geological formations. Depending on their functional group chemistry and macromolecular structure, naturally occurring organic molecules (NOM) possess a high tendency towards actinide complexation reactions. However, the compositional and structural heterogeneity of NOM and mixed aggregates with inorganic phases makes speciation by spectromicroscopy techniques highly desirable. The applicability of Scanning Transmission X-ray Microscopy (STXM) as a speciation tool for the characterization of NOM is demonstrated for a multifunctional natural organic acid (chlorogenic acid), Eu(III)-loaded humic acid (HA) aggregates and Eu(III)-oxo/hydroxide/HA hetero-aggregates. It is shown that in situ probing of HA functional group chemistry down to a spatial resolution < 100 nm (i.e., less than femto-liter sampled volumes) is feasible, at the same time revealing morphological details on NOM aggregates and NOM/mineral associations. (orig.)

  19. A cost function for the natural gas transmission industry: further considerations

    International Nuclear Information System (INIS)

    Massol, O.

    2009-09-01

    This article studies the cost function for the natural gas transmission industry. 60 years ago, Hollis B. Chenery published an important contribution that demonstrated how, in that particular industry, the production function of micro-economic theory can be rewritten with engineering variables (Chenery, 1949). In 2008, an article published in The Engineering Economist (Yepez, 2008) provided a refreshing revival on Chenery's seminal thoughts. In addition to a tribute to the late H.B. Chenery, this document offers some further comments and extensions on Yepez (2008). It provides a statistically estimated characterisation of the long-run scale economies and a discussion on the short-run economics of the duplication of existing equipments. As a first extension, we study the optimal design for infrastructure that is planned to transport a seasonally-varying flow of natural gas. The second extension analyzes the optimal degree of excess capacity to be built into a new infrastructure by a firm that expects a random rise in its output during the infrastructure's lifetime. (author)

  20. Methane Emissions from the Natural Gas Transmission and Storage System in the United States.

    Science.gov (United States)

    Zimmerle, Daniel J; Williams, Laurie L; Vaughn, Timothy L; Quinn, Casey; Subramanian, R; Duggan, Gerald P; Willson, Bryan; Opsomer, Jean D; Marchese, Anthony J; Martinez, David M; Robinson, Allen L

    2015-08-04

    The recent growth in production and utilization of natural gas offers potential climate benefits, but those benefits depend on lifecycle emissions of methane, the primary component of natural gas and a potent greenhouse gas. This study estimates methane emissions from the transmission and storage (T&S) sector of the United States natural gas industry using new data collected during 2012, including 2,292 onsite measurements, additional emissions data from 677 facilities and activity data from 922 facilities. The largest emission sources were fugitive emissions from certain compressor-related equipment and "super-emitter" facilities. We estimate total methane emissions from the T&S sector at 1,503 [1,220 to 1,950] Gg/yr (95% confidence interval) compared to the 2012 Environmental Protection Agency's Greenhouse Gas Inventory (GHGI) estimate of 2,071 [1,680 to 2,690] Gg/yr. While the overlap in confidence intervals indicates that the difference is not statistically significant, this is the result of several significant, but offsetting, factors. Factors which reduce the study estimate include a lower estimated facility count, a shift away from engines toward lower-emitting turbine and electric compressor drivers, and reductions in the usage of gas-driven pneumatic devices. Factors that increase the study estimate relative to the GHGI include updated emission rates in certain emission categories and explicit treatment of skewed emissions at both component and facility levels. For T&S stations that are required to report to the EPA's Greenhouse Gas Reporting Program (GHGRP), this study estimates total emissions to be 260% [215% to 330%] of the reportable emissions for these stations, primarily due to the inclusion of emission sources that are not reported under the GHGRP rules, updated emission factors, and super-emitter emissions.

  1. The Transmission of U.S. Election Cycles to International Stock Returns

    OpenAIRE

    Stephen R Foerster; John J Schmitz

    1997-01-01

    This paper examines the international pervasiveness and importance of the previously uncovered four-year U.S. election cycle whereby U.S. stock returns are significantly lower, and negative, in year 2 following U.S. presidential election relative to years 1, 3 and 4. All eighteen countries examined over the 1957 to 1996 time period possess lower local currency stock market capital gains returns in year 2 (-0.66%) relative to the average capital gains of years 1, 3 and 4 (11.68%). These predom...

  2. Long distance electron transmission couples sulphur, iron, calcium and oxygen cycling in marine sediment

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Nielsen, Lars Peter

    sulfide oxidation leads to electric field formation, sulfide depletion and acidification of the upper centimeters of the sediment. This promoted ion migration and dissolution of carbonates and iron sulfides. Sulfide released from iron sulfides was the major e-donor in the system. Ferrous iron released...... from iron sulfides was to a large extend deposited in the oxic zone as iron oxides and Ca2+ eventually precipitates at the surface as due to high pH caused by cathodic oxygen reduction. The result show how long distance electron transmission allows oxygen to drive the allocation of important minerals...... geochemical alterations in the upper centimetres of the anoxic sediment: Sulphides were oxidized to sulphate in anoxic sediment layers. Electrons from this half-reaction were passed to the oxic layers cm above. In this way the domain of oxygen was extended far beyond it’s physically presence. Bioelectrical...

  3. Life Cycle Assessment Of Hydrogen Production From Natural Gas Reforming Process

    International Nuclear Information System (INIS)

    Ozturk, M.

    2010-01-01

    Society has become concerned about the issues of natural resource depletion and environmental degradation. The environmental performance of products or processes has become a key issue, which is why ways to minimize the effects on the environment are investigated. The most effective tool for this purpose is called life cycle assessment (LCA). This concept considers the entire life cycle of product or process. The life cycle of a product begins with the extraction of raw materials from the earth to create the product and ends at the point when all materials are returned to the earth. LCA makes it possible to estimate the cumulative environmental impacts resulting from all stages in the product life cycle, often including impacts not considered in more traditional analyses. Therefore, LCA provides a comprehensive view of the environmental aspects of the product or process and a more accurate picture of the true environmental trade-offs in product selection. In the case of this study, life cycle assessments of hydrogen production via natural gas reforming process are investigated for environmental affect.

  4. Blood meal sources of wild and domestic Triatoma infestans (Hemiptera: Reduviidae) in Bolivia: connectivity between cycles of transmission of Trypanosoma cruzi.

    Science.gov (United States)

    Buitrago, Rosio; Bosseno, Marie-France; Depickère, Stéphanie; Waleckx, Etienne; Salas, Renata; Aliaga, Claudia; Barnabé, Christian; Brenière, Simone Frédérique

    2016-04-18

    Chagas disease is a major public health problem in Latin America. Its etiologic agent, Trypanosoma cruzi, is mainly transmitted through the contaminated faeces of blood-sucking insects called triatomines. Triatoma infestans is the main vector in various countries in South America and recently, several foci of wild populations of this species have been described in Bolivia and other countries. These wild populations are suspected of affecting the success of insecticide control campaigns being carried out in South America. To assess the risk that these T. infestans populations pose to human health, it is helpful to determine blood meal sources. In the present work, blood meals were identified in various Bolivian wild T. infestans populations and in three specific areas, in both wild and intra-peridomestic populations to assess the links between wild and domestic cycles of T. cruzi transmission. PCR-HDA and sequencing of Cytb gene were used to identify these blood meal sources. Fourteen vertebrate species were identified as wild blood meal sources. Of those, the most prevalent species were two Andean endemic rodents, Octodontomys gliroides (36%) and Galea musteloides (30%), while humans were the third most prevalent source (18.7%). Of 163 blood meals from peridomestic areas, more than half were chickens, and the others were generally domestic animals or humans. Interestingly, blood from wild animals was identified in triatomines captured in the peridomestic and domestic environment, and blood from domestic animals was found in triatomines captured in the wild, revealing links between wild and domestic cycles of T. cruzi transmission. The current study suggests that wild T. infestans attack humans in the wild, but is also able to bite humans in domestic settings before going back to its natural environment. These results support the risk to human health posed by wild populations of T. infestans.

  5. In situ transmission electron microscopy observation of pulverization of aluminum nanowires and evolution of the thin surface Al2O3 layers during lithiation-delithiation cycles.

    Science.gov (United States)

    Liu, Yang; Hudak, Nicholas S; Huber, Dale L; Limmer, Steven J; Sullivan, John P; Huang, Jian Yu

    2011-10-12

    Lithiation-delithiation cycles of individual aluminum nanowires (NWs) with naturally oxidized Al(2)O(3) surface layers (thickness 4-5 nm) were conducted in situ in a transmission electron microscope. Surprisingly, the lithiation was always initiated from the surface Al(2)O(3) layer, forming a stable Li-Al-O glass tube with a thickness of about 6-10 nm wrapping around the NW core. After lithiation of the surface Al(2)O(3) layer, lithiation of the inner Al core took place, which converted the single crystal Al to a polycrystalline LiAl alloy, with a volume expansion of about 100%. The Li-Al-O glass tube survived the 100% volume expansion, by enlarging through elastic and plastic deformation, acting as a solid electrolyte with exceptional mechanical robustness and ion conduction. Voids were formed in the Al NWs during the initial delithiation step and grew continuously with each subsequent delithiation, leading to pulverization of the Al NWs to isolated nanoparticles confined inside the Li-Al-O tube. There was a corresponding loss of capacity with each delithiation step when arrays of NWs were galvonostatically cycled. The results provide important insight into the degradation mechanism of lithium-alloy electrodes and into recent reports about the performance improvement of lithium ion batteries by atomic layer deposition of Al(2)O(3) onto the active materials or electrodes.

  6. Radioactive decay properties of CANDU fuel. Volume 1: the natural uranium fuel cycle

    International Nuclear Information System (INIS)

    Clegg, L.J.; Coady, J.R.

    1977-01-01

    The two books of Volume 1 comprise the first in a three-volume series of compilations on the radioactive decay propertis of CANDU fuel and deal with the natural uranium fuel cycle. Succeeding volumes will deal with fuel cycles based on plutonium recycle and thorium. In Volume 1 which is divided into three parts, the computer code CANIGEN was used to obtain the mass, activity, decay heat and toxicity of CANDU fuel and its component isotopes. Data are also presented on gamma spectra and neutron emissions. Part 3 contains the data relating to the plutonium product and the high level wastes produced during fuel reprocessing. (author)

  7. Economic comparison of clean coal generating technologies with natural gas-combined cycle systems

    International Nuclear Information System (INIS)

    Sebesta, J.J.; Hoskins, W.W.

    1990-01-01

    This paper reports that there are four combustion technologies upon which U.S. electric utilities are expected to rely for the majority of their future power generating needs. These technologies are pulverized coal- fired combustion (PC); coal-fired fluidized bed combustion (AFBC); coal gasification, combined cycle systems (CGCC); and natural gas-fired combined cycle systems (NGCC). The engineering and economic parameters which affect the choice of a technology include capital costs, operating and maintenance costs, fuel costs, construction schedule, process risk, environmental and site impacts, fuel efficiency and flexibility, plant availability, capacity factors, timing of startup, and the importance of utility economic and financial factors

  8. Using cryogenic exergy of liquefied natural gas for electricity production with the Stirling cycle

    International Nuclear Information System (INIS)

    Dong, Hui; Zhao, Liang; Zhang, Songyuan; Wang, Aihua; Cai, Jiuju

    2013-01-01

    Cryogenic generation is one of the most important ways to utilize cold energy during LNG (liquefied natural gas) regasification. This paper fundamentally investigates LNG cryogenic generation with the Stirling cycle method based on previous studies. A basic process of LNG cryogenic generation with the Stirling cycle was presented initially with seawater and LNG as heat source and heat sink. And its thermodynamic analysis was performed to verify the theoretical feasibility of the Stirling cycle method. The generating capacity, the exergy efficiency and the cold energy utilization efficiency of the basic process were also calculated. Subsequently, the influences of evaporation pressure on net work, equipment performance and comprehensive efficiency of cold energy utilization were discussed and the effect of LNG mass flow as well as the ambient temperature was also studied. Finally an improved process of LNG cryogenic generation with Stirling cycle method combined with an air liquefaction process is proposed as feasibility in improvements of the basic process. - Highlights: • We propose a basic process of LNG cryogenic generation with the Stirling cycle. • Seawater and LNG were applied as heat source and heat sink of the basic process. • The max generating capacity of the basic process is 51 kWh/tLNG. • The max cold energy utilization efficiency of the basic process is 0.56. • We also discussed some feasibilities of optimization of the basic cycle

  9. Transmission rates of the bacterial endosymbiont, Neorickettsia risticii, during the asexual reproduction phase of its digenean host, Plagiorchis elegans, within naturally infected lymnaeid snails.

    Science.gov (United States)

    Greiman, Stephen E; Tkach, Vasyl V; Vaughan, Jefferson A

    2013-10-22

    Neorickettsia are obligate intracellular bacterial endosymbionts of digenean parasites present in all lifestages of digeneans. Quantitative information on the transmission of neorickettsial endosymbionts throughout the complex life cycles of digeneans is lacking. This study quantified the transmission of Neorickettsia during the asexual reproductive phase of a digenean parasite, Plagiorchis elegans, developing within naturally parasitized lymnaeid pond snails. Lymnaea stagnalis snails were collected from 3 ponds in Nelson County, North Dakota and screened for the presence of digenean cercariae. Cercariae were identified to species by PCR and sequencing of the 28S rRNA gene. Neorickettsia infections were initially detected using nested PCR and sequencing of a partial 16S rRNA gene of pooled cercariae shed from each parasitized snail. Fifty to 100 single cercariae or sporocysts were isolated from each of six parasitized snails and tested for the presence of Neorickettsia using nested PCR to estimate the efficiency at which Neorickettsia were transmitted to cercariae during asexual development of the digenean. A total of 616 L. stagnalis were collected and 240 (39%) shed digenean cercariae. Of these, 18 (8%) were Neorickettsia-positive. Six Neorickettsia infections were selected to determine the transmission efficiency of Neorickettsia from mother to daughter sporocyst and from daughter sporocyst to cercaria. The prevalence of neorickettsiae in cercariae varied from 11 to 91%. The prevalence of neorickettsiae in sporocysts from one snail was 100%. Prevalence of Neorickettsia infection in cercariae of Plagiorchis elegans was variable and never reached 100%. Reasons for this are speculative, however, the low prevalence of Neorickettsia observed in some of our samples (11 to 52%) differs from the high prevalence of other, related bacterial endosymbionts, e.g. Wolbachia in Wolbachia-dependent filariid nematodes, where the prevalence among progeny is universally 100

  10. Organohalide respiration in pristine environments: implications for the natural halogen cycle.

    Science.gov (United States)

    Atashgahi, Siavash; Häggblom, Max M; Smidt, Hauke

    2018-03-01

    Halogenated organic compounds, also termed organohalogens, were initially considered to be of almost exclusively anthropogenic origin. However, over 5000 naturally synthesized organohalogens are known today. This has also fuelled the hypothesis that the natural and ancient origin of organohalogens could have primed development of metabolic machineries for their degradation, especially in microorganisms. Among these, a special group of anaerobic microorganisms was discovered that could conserve energy by reducing organohalogens as terminal electron acceptor in a process termed organohalide respiration. Originally discovered in a quest for biodegradation of anthropogenic organohalogens, these organohalide-respiring bacteria (OHRB) were soon found to reside in pristine environments, such as the deep subseafloor and Arctic tundra soil with limited/no connections to anthropogenic activities. As such, accumulating evidence suggests an important role of OHRB in local natural halogen cycles, presumably taking advantage of natural organohalogens. In this minireview, we integrate current knowledge regarding the natural origin and occurrence of industrially important organohalogens and the evolution and spread of OHRB, and describe potential implications for natural halogen and carbon cycles. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  11. In situ redox cycle of a nickel–YSZ fuel cell anode in an environmental transmission electron microscope

    DEFF Research Database (Denmark)

    Jeangros, Quentin; Faes, Antonin; Wagner, Jakob Birkedal

    2010-01-01

    triggers the reduction reaction. During Ni reoxidation, the creation of a porous structure, due to mass transport, accounts for the redox instability of the Ni-based anode. Both the expansion of NiO during a redox cycle and the presence of stress in the yttria-stabilized zirconia grains are observed......Environmental transmission electron microscopy is used in combination with density functional theory calculations to study the redox stability of a nickel/yttria-stabilized zirconia solid oxide fuel cell anode. The results reveal that the transfer of oxygen from NiO to yttria-stabilized zirconia...... directly. Besides providing an understanding of the Ni–YSZ anode redox degradation, the observations are used to propose an alternative anode design for improved redox tolerance....

  12. Research on influence of gear parameters on noise, vibrations and harshness conditions for automatic transmissions run-off cycle

    Directory of Open Access Journals (Sweden)

    Pascalau Nelu

    2017-01-01

    Full Text Available Noise vibration harshness (NVH defines, as a whole, that specific field within automotive industry, that studies mostly the noise and vibrations for different assemblies (such as chassis or drivetrain – gearbox or complete vehicles, particularly cars and trucks. Gear quality parameters have been studied and it has been experienced that these parameters have an important relevance for NVH topic. Therefore, this paper introduces a case-study, as to highlight the influence of two of these parameters, profile angle deviation (fHα and tooth trace angle deviation (fHβ, on run-off cycle on test benches, for high-performance automatic transmission, designed for passenger vehicles. The demand for high accuracy is mandatory, so fine adjustments are required, as could be further observed, in order to accomplish the requirements for a lower NVH run-off rate, while the whole life-time.

  13. Establishment of a mouse model for the complete mosquito-mediated transmission cycle of Zika virus.

    Directory of Open Access Journals (Sweden)

    Yi-Ping Kuo

    2018-04-01

    Full Text Available Zika virus (ZIKV is primarily transmitted by Aedes mosquitoes in the subgenus Stegomyia but can also be transmitted sexually and vertically in humans. STAT1 is an important downstream factor that mediates type I and II interferon signaling. In the current study, we showed that mice with STAT1 knockout (Stat1-/- were highly susceptible to ZIKV infection. As low as 5 plaque-forming units of ZIKV could cause viremia and death in Stat1-/- mice. ZIKV replication was initially detected in the spleen but subsequently spread to the brain with concomitant reduction of the virus in the spleen in the infected mice. Furthermore, ZIKV could be transmitted from mosquitoes to Stat1-/- mice back to mosquitoes and then to naïve Stat1-/- mice. The 50% mosquito infectious dose of viremic Stat1-/- mouse blood was close to 810 focus-forming units (ffu/ml. Our further studies indicated that the activation of macrophages and conventional dendritic cells were likely critical for the resolution of ZIKV infection. The newly developed mouse and mosquito transmission models for ZIKV infection will be useful for the evaluation of antiviral drugs targeting the virus, vector, and host.

  14. Information transmission and market interactions across the Atlantic. An empirical study on the natural gas market

    International Nuclear Information System (INIS)

    Kao, Chung-Wei; Wan, Jer-Yuh

    2009-01-01

    This paper studies the international information transmission and market interactions in the U.S. and U.K. natural gas markets. Three well documented approaches are used to measure the relative importance on the process of price discovery under a quadvariate system. After adjusting the effects of nonsynchronous trading prices, robust results indicate our system that includes spot and futures prices within the two countries are driven by one common factor. Information disseminates efficiently among the four markets concerned. The U.S. futures market dominates as the center for price discovery. The U.K. futures market comes as the second. The spot markets in the U.S. and U.K. are less efficient than their corresponding futures market, where the U.K. spot market contributes the least and almost zero to the price discovery process. Asymmetric volatility spillovers are found in three of the four markets. Volatility in the U.S. futures market increases with positive returns which illustrates the inverse leverage effect in most of the commodity market. Volatilities in the spot markets are negatively related to returns, which is analogous to the traditional leverage effect prevailing in most of the equity stock markets. (author)

  15. Naturally acquired antibody responses to recombinant Pfs230 and Pfs48/45 transmission blocking vaccine candidates

    NARCIS (Netherlands)

    Jones, S; Grignard, L.; Nebie, I.; Chilongola, J.; Dodoo, D.; Sauerwein, R.W.; Theisen, M.; Roeffen, W.F.; Singh, S.K; Singh, R.K.; Kyei-Baafour, E.; Tetteh, K.; Drakeley, C.; Bousema, T.

    2015-01-01

    OBJECTIVES: Pfs48/45 and Pfs230 are Plasmodium falciparum sexual stage proteins and promising malaria transmission-blocking vaccine candidates. Antibody responses against these proteins may be naturally acquired and target antigens may be under selective pressure. This has consequences for the

  16. Analysis of fuel cycles with natural uranium; Analiza gorivnih ciklusa sa prirodnim uranom

    Energy Technology Data Exchange (ETDEWEB)

    Stojanovic, A [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1965-05-15

    A method was developed and a computer code was written for analysis of fuel cycles and it was applied for heavy water and graphite moderated power reactors. Among a variety of possibilities, three methods which enable best utilization of natural uranium and plutonium production were analyzed. Analysis has shown that reprocessing of irradiated uranium and plutonium utilization in the same or similar type of reactor could increase significantly utilization of natural uranium. Increase of burnup is limited exclusively by costs of reprocessing, plutonium extraction and fabrication of new fuel elements.

  17. Bovine coronavirus in naturally and experimentally exposed calves; viral shedding and the potential for transmission.

    Science.gov (United States)

    Oma, Veslemøy Sunniva; Tråvén, Madeleine; Alenius, Stefan; Myrmel, Mette; Stokstad, Maria

    2016-06-13

    Bovine coronavirus (BCoV) is a widely distributed pathogen, causing disease and economic losses in the cattle industry worldwide. Prevention of virus spread is impeded by a lack of basic knowledge concerning viral shedding and transmission potential in individual animals. The aims of the study were to investigate the duration and quantity of BCoV shedding in feces and nasal secretions related to clinical signs, the presence of virus in blood and tissues and to test the hypothesis that seropositive calves are not infectious to naïve in-contact calves three weeks after BCoV infection. A live animal experiment was conducted, with direct contact between animal groups for 24 h as challenge procedure. Four naïve calves were commingled with a group of six naturally infected calves and sequentially euthanized. Two naïve sentinel calves were commingled with the experimentally exposed group three weeks after exposure. Nasal swabs, feces, blood and tissue samples were analyzed for viral RNA by RT-qPCR, and virus isolation was performed on nasal swabs. Serum was analyzed for BCoV antibodies. The calves showed mild general signs, and the most prominent signs were from the respiratory system. The overall clinical score corresponded well with the shedding of viral RNA the first three weeks after challenge. General depression and cough were the signs that correlated best with shedding of BCoV RNA, while peak respiratory rate and peak rectal temperature appeared more than a week later than the peak shedding. Nasal shedding preceded fecal shedding, and the calves had detectable amounts of viral RNA intermittently in feces through day 35 and in nasal secretions through day 28, however virus isolation was unsuccessful from day six and day 18 from the two calves investigated. Viral RNA was not detected in blood, but was found in lymphatic tissue through day 42 after challenge. Although the calves were shedding BCoV RNA 21 days after infection the sentinel animals were not infected

  18. Nature of vegetative cycle in Phytophthora parasitica Dastur and palmivora (BUTLER) BUTLER

    International Nuclear Information System (INIS)

    Le Grand-Pernot, Francoise; Pellegrin, F.

    1976-01-01

    Up to now, neither cytological nor genetical studies have clearly demonstrated the 'ploidy' degree of somatic nuclei in different species of Phytophthora. Two complementary studies, using biological effect of γ rays upon zoospores, and microspectrophotometric techniques measuring relative amount of DNA by nucleus in zoospores or in hyphae, allowed to demonstrate diploid nature of the vegetative phase in P. palmivora (BUTLER) BUTLER and P. parasitica DASTUR cycles [fr

  19. Natural cycles and agricultural inputs: a farm gate Ecological Footprint analysis

    Science.gov (United States)

    Passeri, Nicolo; Blasi, Emanuele; Borucke, Michael; Galli, Alessandro; Franco, Silvio

    2014-05-01

    Land suitability for different crops depends on soil, water and climate conditions, as well as farmers' cultivation choices. Moreover, the use of agricultural inputs affects the natural cycles of crops and impacts their production. By assessing the ecological performance of farms as influenced by crop types, cultivation choices and land suitability one can therefore evaluate the effectiveness of agricultural practices and governance's options. Ecological Footprint accounts can be used to measure such ecological performance. These accounts track human demand for natural resources and ecological services and compare this demand with nature ability to regenerate these resource and services. This regenerative capacity is called biocapacity. Both demand (Footprint) and supply (biocapacity) are expressed in global hectares. Farming different from most other human activities, not only uses natural resources, but also enhances or erodes ecological supply. It therefore affects all factors that determine both Footprint and biocapacity. Climate, farmers' skills and choices (fertilizers, pesticides, machines) determine crop productivity, and to what extent crops preserve or compromise soils. The aim of this work is to evaluate how farmer's choices affect resources overexploitation. The study analysed how the use of inputs influences natural cycles within farm boundaries. This result from a pilot case study will show how particular farming practices affect both the farm's biocapacity and Ecological Footprint. Such analysis is relevant for informing involved stakeholders, namely the farmers on more sustainable agricultural practices and the policy makers on more suitable agricultural policies.

  20. Life cycle water consumption for shale gas and conventional natural gas.

    Science.gov (United States)

    Clark, Corrie E; Horner, Robert M; Harto, Christopher B

    2013-10-15

    Shale gas production represents a large potential source of natural gas for the nation. The scale and rapid growth in shale gas development underscore the need to better understand its environmental implications, including water consumption. This study estimates the water consumed over the life cycle of conventional and shale gas production, accounting for the different stages of production and for flowback water reuse (in the case of shale gas). This study finds that shale gas consumes more water over its life cycle (13-37 L/GJ) than conventional natural gas consumes (9.3-9.6 L/GJ). However, when used as a transportation fuel, shale gas consumes significantly less water than other transportation fuels. When used for electricity generation, the combustion of shale gas adds incrementally to the overall water consumption compared to conventional natural gas. The impact of fuel production, however, is small relative to that of power plant operations. The type of power plant where the natural gas is utilized is far more important than the source of the natural gas.

  1. Proposing a novel combined cycle for optimal exergy recovery of liquefied natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Salimpour, M.R.; Zahedi, M.A. [Isfahan University of Technology (Iran, Islamic Republic of). Department of Mechanical Engineering

    2012-08-15

    The effective utilization of the cryogenic exergy associated with liquefied natural gas (LNG) vaporization is important. In this paper, a novel combined power cycle is proposed which utilizes LNG in different ways to enhance the power generation of a power plant. In addition to the direct expansion in the appropriate expander, LNG is used as a low-temperature heat sink for a middle-pressure gas cycle which uses nitrogen as working fluid. Also, LNG is used to cool the inlet air of an open Brayton gas turbine cycle. These measures are accomplished to improve the exergy recovery of LNG. In order to analyze the performance of the system, the influence of several key parameters such as pressure ratio of LNG turbine, ratio of the mass flow rate of LNG to the mass flow rate of air, pressure ratio of different compressors, LNG pressure and inlet pressure of nitrogen compressor, on the thermal efficiency and exergy efficiency of the offered cycle is investigated. Finally, the proposed combined cycle is optimized on the basis of first and second laws of thermodynamics. (orig.)

  2. Tuning growth cycles of Brassica crops via natural antisense transcripts of BrFLC.

    Science.gov (United States)

    Li, Xiaorong; Zhang, Shaofeng; Bai, Jinjuan; He, Yuke

    2016-03-01

    Several oilseed and vegetable crops of Brassica are biennials that require a prolonged winter cold for flowering, a process called vernalization. FLOWERING LOCUS C (FLC) is a central repressor of flowering. Here, we report that the overexpression of natural antisense transcripts (NATs) of Brassica rapa FLC (BrFLC) greatly shortens plant growth cycles. In rapid-, medium- and slow-cycling crop types, there are four copies of the BrFLC genes, which show extensive variation in sequences and expression levels. In Bre, a biennial crop type that requires vernalization, five NATs derived from the BrFLC2 locus are rapidly induced under cold conditions, while all four BrFLC genes are gradually down-regulated. The transgenic Bre lines overexpressing a long NAT of BrFLC2 do not require vernalization, resulting in a gradient of shortened growth cycles. Among them, a subset of lines both flower and set seeds as early as Yellow sarson, an annual crop type in which all four BrFLC genes have non-sense mutations and are nonfunctional in flowering repression. Our results demonstrate that the growth cycles of biennial crops of Brassica can be altered by changing the expression levels of BrFLC2 NATs. Thus, BrFLC2 NATs and their transgenic lines are useful for the genetic manipulation of crop growth cycles. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  3. Widespread recombination, reassortment, and transmission of unbalanced compound viral genotypes in natural arenavirus infections.

    Directory of Open Access Journals (Sweden)

    Mark D Stenglein

    2015-05-01

    Full Text Available Arenaviruses are one of the largest families of human hemorrhagic fever viruses and are known to infect both mammals and snakes. Arenaviruses package a large (L and small (S genome segment in their virions. For segmented RNA viruses like these, novel genotypes can be generated through mutation, recombination, and reassortment. Although it is believed that an ancient recombination event led to the emergence of a new lineage of mammalian arenaviruses, neither recombination nor reassortment has been definitively documented in natural arenavirus infections. Here, we used metagenomic sequencing to survey the viral diversity present in captive arenavirus-infected snakes. From 48 infected animals, we determined the complete or near complete sequence of 210 genome segments that grouped into 23 L and 11 S genotypes. The majority of snakes were multiply infected, with up to 4 distinct S and 11 distinct L segment genotypes in individual animals. This S/L imbalance was typical: in all cases intrahost L segment genotypes outnumbered S genotypes, and a particular S segment genotype dominated in individual animals and at a population level. We corroborated sequencing results by qRT-PCR and virus isolation, and isolates replicated as ensembles in culture. Numerous instances of recombination and reassortment were detected, including recombinant segments with unusual organizations featuring 2 intergenic regions and superfluous content, which were capable of stable replication and transmission despite their atypical structures. Overall, this represents intrahost diversity of an extent and form that goes well beyond what has been observed for arenaviruses or for viruses in general. This diversity can be plausibly attributed to the captive intermingling of sub-clinically infected wild-caught snakes. Thus, beyond providing a unique opportunity to study arenavirus evolution and adaptation, these findings allow the investigation of unintended anthropogenic impacts on

  4. Modified natural cycle IVF and mild IVF: a 10 year Swedish experience.

    Science.gov (United States)

    Aanesen, Arthur; Nygren, Karl-Gösta; Nylund, Lars

    2010-01-01

    Modified natural cycle IVF (mnc-IVF) or mild IVF (m-IVF) was offered to selected patients between 1996 and 2007; 43 patients during 129 cycles were treated with mnc-IVF and 145 couples during 250 cycles were treated with m-IVF. Comparison with outcome from conventional IVF cycles during the same time period and in the same clinic was performed. Although 53.5 and 39.6% of started cycles respectively never reached embryo transfer, the ongoing pregnancy rates per embryo transfer were 26.7% for mnc-IVF and 27.2% for m-IVF. During the same time period, cancellation rate for conventional IVF was 13.7% and the ongoing pregnancy rate per embryo transfer was 34.3%. For patients > or =38years of age, the ongoing pregnancy rate per embryo transfer was 17.5% in the m-IVF group. None of the patients aged > or =38years in the mnc-IVF group achieved an ongoing pregnancy. For patients treated with conventional IVF, the > or =38years of age pregnancy rate per embryo transfer was 27.0%. Costs of medication for m-IVF and mnc-IVF were 96.3 and 97.5% less than for the least expensive conventional IVF cycle respectively. Pregnancy rates per embryo transfer are acceptable for these treatment modalities, the cost for medication is low, risks for complications are dramatically reduced, and the treatments may be more psychologically acceptable to the patients. Copyright (c) 2009 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  5. The problem of IVF cost in developing countries: has natural cycle IVF a place?

    Science.gov (United States)

    Shahin, Ahmed Y

    2007-07-01

    Infertility represents a national health problem in some African countries. Limited financial health resources in developing countries are a major obstacle facing infertility management. IVF is the definitive line of treatment for many couples. Stimulation cycles are associated with risks of ovarian hyperstimulation syndrome and multiple pregnancy. This study evaluates the client acceptability of stimulated versus natural cycle IVF among couples attending one infertility clinic, with respect to cost and pregnancy outcome. Of the patients who were indicated for IVF, 15% (16/107) cancelled, due mostly (12/16, 75%) to financial reasons. The majority of patients who completed their IVF treatment (82/91, 90.1%) felt the price of the medical service offered was high, and 68.1% (62/91) accepted the idea of having cheaper drugs with fewer side effects but with possibly lower chances of pregnancy. Natural cycle IVF has emerged as a potential option that might be suitable for patients worldwide, especially in developing countries.

  6. Environmental analysis of natural gas life cycle; Analisi ambientale del ciclo di vita del gas naturale

    Energy Technology Data Exchange (ETDEWEB)

    Riva, A.; D' Angelosante, S.; Trebeschi, C. [Snam SpA, Rome (Italy)

    2000-12-01

    Life Cycle Assessment is a method aimed at identifying the environmental effects connected with a given product, process or activity during its whole life cycle. The evaluation of published studies and the application of the method to electricity production with fossil fuels, by using data from published databases and data collected by the gas industry, demonstrate the importance and difficulties to have reliable and updated data required for a significant life cycle assessment. The results show that the environmental advantages of natural gas over the other fossil fuels in the final use stage increase still further if the whole life cycle of the fuels, from production to final consumption, is taken into account. [Italian] L'analisi del ciclo di vita e' una metodologia che consente di identificare gli effetti ambientali associati ad un prodotto, processo o attivita' lungo il loro ciclo di vita. La valutazione di studi pubblicati e l'applicazione della metodologia alla produzione di energia elettrica da combustibili fossili, utilizzando dati provenienti da banche dati di letteratura e raccolti dall'industria del gas, dimostrano l'importanza e la difficolta' di avere a disposizione dati affidabili ed aggiornati, necessari per un'analisi significativa del ciclo di vita. I risultati mostrano che i vantaggi ambientali del gas naturale rispetto agli altri combustibili fossili nella fase di utilizzo finale, aumentano ulteriormente se si considera l'intero ciclo di vita dei diversi combustibili, dalla produzione al consumo finale.

  7. The Nature of Exposure Drives Transmission of Nipah Viruses from Malaysia and Bangladesh in Ferrets.

    Directory of Open Access Journals (Sweden)

    Bronwyn A Clayton

    2016-06-01

    Full Text Available Person-to-person transmission is a key feature of human Nipah virus outbreaks in Bangladesh. In contrast, in an outbreak of Nipah virus in Malaysia, people acquired infections from pigs. It is not known whether this important epidemiological difference is driven primarily by differences between NiV Bangladesh (NiV-BD and Malaysia (NiV-MY at a virus level, or by environmental or host factors. In a time course study, ferrets were oronasally exposed to equivalent doses of NiV-BD or NiV-MY. More rapid onset of productive infection and higher levels of virus replication in respiratory tract tissues were seen for NiV-BD compared to NiV-MY, corroborating our previous report of increased oral shedding of NiV-BD in ferrets and suggesting a contributory mechanism for increased NiV-BD transmission between people compared to NiV-MY. However, we recognize that transmission occurs within a social and environmental framework that may have an important and differentiating role in NiV transmission rates. With this in mind, ferret-to-ferret transmission of NiV-BD and NiV-MY was assessed under differing viral exposure conditions. Transmission was not identified for either virus when naïve ferrets were cohoused with experimentally-infected animals. In contrast, all naïve ferrets developed acute infection following assisted and direct exposure to oronasal fluid from animals that were shedding either NiV-BD or NiV-MY. Our findings for ferrets indicate that, although NiV-BD may be shed at higher levels than NiV-MY, transmission risk may be equivalently low under exposure conditions provided by cohabitation alone. In contrast, active transfer of infected bodily fluids consistently results in transmission, regardless of the virus strain. These observations suggest that the risk of NiV transmission is underpinned by social and environmental factors, and will have practical implications for managing transmission risk during outbreaks of human disease.

  8. SPECIES COMPOSITION OF MALARIAL MOSQUITOES KHARKIV REGION. NATURAL FACTORS OF MALARIA TRANSMISSION

    Directory of Open Access Journals (Sweden)

    Gazzawi - Rogozinа L. V.

    2015-05-01

    Full Text Available Introduction. This article describes the species composition of the dominant Anopheles mosquitoes in the Kharkiv region, the season of their possible effective infection, as well as ongoing anti-malaria activities . Key words: malaria , mosquitoes, p . Anopheles, epidemiology, census, hydraulic events. Material & methods. The analysis of entomological and meteorological situation in Ukraine and in the Kharkiv region according to data of the Ukrainian Center of control and monitoring of diseases of the Ministry of Health of Ukraine and Kharkiv regional laboratory center. Collection of material (imaginal and larval was carried out on the territory of natural and artificial water bodies of Kharkiv region in the period 2013 - 2014. When collecting the material used conventional accounting methods mosquito populations. On the territory of the region under study, we have found 30 species of mosquitoes three genera: Anopheles, Culex, Aedes. Results & discussion. Epidemiological role of each species of mosquitoes depends on several conditions. Dangerous vector species can only be found in large numbers, a significant percentage of individuals in a population that feeds on the blood of man, having a sufficiently long season activity and a sufficient number of females surviving to age possible maturation of sporozoites in their body. In Ukraine, the major carriers - Anopheles maculipennis, An. m. messeae, An. m. atroparvus, An. claviger, An. plumbeus, An. hyrcanus. Mosquito species registered in the territory of the Kharkiv region are susceptible to currently known types of human malaria parasites . Moreover, the dominant species in terms of urban landscapes are An.maculipennis and An.messeae . These species possess all the qualities necessary to be considered dangerous malaria vector control. They are well infected with the three main types of human parasites. In the study area , in terms of urban landscapes, gonoaktivnye females occurs within 3

  9. Impact of anthropogenic and natural environmental changes on Echinococcus transmission in Ningxia Hui Autonomous Region, the People's Republic of China.

    Science.gov (United States)

    Yang, Yu Rong; Clements, Archie C A; Gray, Darren J; Atkinson, Jo-An M; Williams, Gail M; Barnes, Tamsin S; McManus, Donald P

    2012-07-24

    Echinococcus transmission is known to be affected by various environmental factors, which may be modified by human influence or natural events including global warming. Considerable population growth in the last fifty years in Ningxia Hui Autonomous Region (NHAR), the People's Republic of China (PRC), has led to dramatic increases in deforestation and modified agricultural practices. In turn, this has resulted in many changes in the habitats for the definitive and intermediate hosts of both Echinococcus granulosus and E. multilocularis, which have increased the risks for transmission of both parasites, affecting echinococcosis prevalence and human disease. Ecological environmental changes due to anthropogenic activities and natural events drive Echinococcus transmission and NHAR provides a notable example illustrating how human activity can impact on a parasitic infection of major public health significance. It is very important to continually monitor these environmental (including climatic) factors that drive the distribution of Echinococcus spp. and their impact on transmission to humans because such information is necessary to formulate reliable future public health policy for echinococcosis control programs and to prevent disease spread.

  10. Hydroclimatic influences on seasonal and spatial cholera transmission cycles: Implications for public health intervention in the Bengal Delta

    Science.gov (United States)

    Akanda, Ali Shafqat; Jutla, Antarpreet S.; Alam, Munirul; de Magny, Guillaume Constantin; Siddique, A. Kasem; Sack, R. Bradley; Huq, Anwar; Colwell, Rita R.; Islam, Shafiqul

    2011-03-01

    Cholera remains a major public health threat in many developing countries around the world. The striking seasonality and annual recurrence of this infectious disease in endemic areas remain of considerable interest to scientists and public health workers. Despite major advances in the ecological and microbiological understanding of Vibrio cholerae, the causative agent of the disease, the role of underlying large-scale hydroclimatic processes in propagating the disease for different seasons and spatial locations is not well understood. Here we show that the cholera outbreaks in the Bengal Delta region are propagated from the coastal to the inland areas and from spring to fall by two distinctly different transmission cycles, premonsoon and postmonsoon, influenced by coastal and terrestrial hydroclimatic processes, respectively. A coupled analysis of the regional hydroclimate and cholera incidence reveals a strong association of the space-time variability of incidence peaks with seasonal processes and extreme climatic events. We explain how the asymmetric seasonal hydroclimatology affects regional cholera dynamics by providing a coastal growth environment for bacteria in spring, while propagating the disease to fall by monsoon flooding. Our findings may serve as the basis for "climate-informed" early warnings and for prompting effective means for intervention and preempting epidemic cholera outbreaks in vulnerable regions.

  11. A Lipidomics Approach in the Characterization of Zika-Infected Mosquito Cells: Potential Targets for Breaking the Transmission Cycle.

    Directory of Open Access Journals (Sweden)

    Carlos Fernando Odir Rodrigues Melo

    Full Text Available Recent outbreaks of Zika virus in Oceania and Latin America, accompanied by unexpected clinical complications, made this infection a global public health concern. This virus has tropism to neural tissue, leading to microcephaly in newborns in a significant proportion of infected mothers. The clinical relevance of this infection, the difficulty to perform accurate diagnosis and the small amount of data in literature indicate the necessity of studies on Zika infection in order to characterize new biomarkers of this infection and to establish new targets for viral control in vertebrates and invertebrate vectors. Thus, this study aims at establishing a lipidomics profile of infected mosquito cells compared to a control group to define potential targets for viral control in mosquitoes. Thirteen lipids were elected as specific markers for Zika virus infection (Brazilian strain, which were identified as putatively linked to the intracellular mechanism of viral replication and/or cell recognition. Our findings bring biochemical information that may translate into useful targets for breaking the transmission cycle.

  12. Nitrogen Cycling and GHG Emissions of Natural and Managed Tropical Ecosystems at Mt. Kilimanjaro

    Science.gov (United States)

    Gutlein, A.; Ralf, K.; Gerschlauer, F.; Dannenmann, M.; Butterbach-Bahl, K.; Diaz-Pines, E.

    2016-12-01

    In a rapidly changing world understanding of natural ecosystems response to human perturbations such as land use and climate changes as well as habitat destruction is crucial with respect to sustainability of ecosystem services. This is particularily true for tropical forest ecosystems which have significant effects on the major biogeochemical cycles and global climate. Here we present a comprehensive dataset of nitrogen cycling and GHG emissions of natural and managed ecosystems along land use and climate gradients at Mt. Kilimanjaro, Tanzania including different forest ecosystems, homegardens, and coffee plantations. Soil N turnover rates were highest in the Ocotea forest and progressively decreased with decreasing annual rainfall and increasing land use intensity. Nitrogen production and immobilization rates positively correlated with soil organic C and total N concentrations as well as substrate availability of dissolved organic C and N, but correlated less with soil ammonium and nitrate concentrations. By using indicators of N retention and characteristics of soil nutrient status, we observed a grouping of faster, but tighter N cycling in the (semi-) natural savanna, Helychrysum and Ocotea forest. This contrasted with a more open N cycle in managed systems (homegarden and coffee plantation) where N was more prone to leaching or gaseous losses due to high nitrate production rates. The partly disturbed lower montane forest ranged in between these two groups. These finding could be supported by differences in natural 15N abundance of litter and soil across all sites. Comparing GHG emissions at the land use gradient showed, that with increasing intensification (lower montane forest - homegarden - coffee plantation) N2O emissions increased but at the same time the soil sink for atmospheric CH4 decreased. GHG emission measurements at the climate gradient (savanna, lower montane, Ocotea and Podocarpus forest, Helychrysum) revealed that differences in soil moisture

  13. Comparative study of the antitumor effect of natural monoterpenes: relationship to cell cycle analysis

    Directory of Open Access Journals (Sweden)

    Abdeslam Jaafari

    2012-06-01

    Full Text Available Monoterpenes have been identified as responsible of important therapeutic effects of plant-extracts. In this work, we try to compare the cytotoxic effect of six monoterpenes (carvacrol, thymol, carveol, carvone, eugenol and isopulegol as well as their molecular mechanisms. The in vitro antitumor activity of the tested products, evaluated against five tumor cell lines, show that the carvacrol is the most cytotoxic monoterpene. The investigation of an eventual synergistic effect of the six natural monoterpenes with two anticancer drugs revealed that there is a significant synergy between them (p<5%. On the other hand, the effect of the tested products on cell cycle progression was examined by flow cytometry after DNA staining in order to investigate the molecular mechanism of their cytotoxic activity. The results revealed that carvacrol and carveol stopped the cell cycle progression in S phase; however, thymol and isopulegol stopped it in G0/G1 phase. Regarding carvone and eugenol, no effect on cell cycle was observed.

  14. ESC expert statement on the effects on mood of the natural cycle and progestin-only contraceptives

    DEFF Research Database (Denmark)

    Merki-Feld, G. S.; Apter, D.; Bartfai, G.

    2017-01-01

    Hormonal fluctuations during the natural cycle, as well as progestins used for hormonal contraception, can exert effects on mood especially in vulnerable women. Negative effects of levonorgestrel-releasing intrauterine contraception on mood are rare....

  15. ESC expert statement on the effects on mood of the natural cycle and progestin-only contraceptives.

    Science.gov (United States)

    Merki-Feld, G S; Apter, D; Bartfai, G; Grandi, G; Haldre, K; Lech, M; Lertxundi, R; Lete, I; Lobo Abascal, P; Raine, S; Roumen, F; Serfaty, D; Shulman, L P; Skouby, S; Bitzer, J

    2017-08-01

    Hormonal fluctuations during the natural cycle, as well as progestins used for hormonal contraception, can exert effects on mood especially in vulnerable women. Negative effects of levonorgestrel-releasing intrauterine contraception on mood are rare.

  16. Single embryo transfer: the role of natural cycle/minimal stimulation IVF in the future.

    Science.gov (United States)

    Nygren, Karl-Gösta

    2007-05-01

    There are several good reasons to assume that single embryo transfer (SET) eventually will become the norm internationally in IVF treatments. A tendency is clearly visible, as demonstrated in the latest IVF World Report. The Nordic countries and Belgium have been leading the way. Sweden at present has 70% SET, with 5% twins and a pregnancy rate per transfer remaining constant at about 30%. As a consequence, recent data show a drastic reduction of the risk of prematurity and therefore of child morbidity and perinatal mortality. It is now time to discuss alternatives to the current clinical policy of quite an aggressive ovarian stimulation in settings where SET is the norm. When and at what proportion could natural cycle/soft stimulation be used? What group of patients would benefit? What will the consequences be in terms of efficacy, safety, cost, time and quality of life? Selection of the most beneficial, rather than the most aggressive, ovarian stimulation protocol by clinicians and by the couples themselves in the future may well include a much wider use of natural cycle/soft stimulation in IVF.

  17. Data base for a CANDU-PHW operating on a once-through, natural uranium fuel cycle

    International Nuclear Information System (INIS)

    1979-07-01

    This report, prepared for INFCE, describes a standard 600 MW(e) CANDU-PHW reactor operating on a once-through natural uranium fuel cycle. Subsequently, data are given for an extrapolated 1000 MW(e) design (the nominal capacity adopted for the INFCE study) operating on the same fuel cycle. (author)

  18. Modified natural cycle versus controlled ovarian hyperstimulation IVF: a cost-effectiveness evaluation of three simulated treatment scenarios

    NARCIS (Netherlands)

    Groen, Henk; Tonch, Nino; Simons, Arnold H. M.; van der Veen, Fulco; Hoek, Annemieke; Land, Jolande A.

    2013-01-01

    Can modified natural cycle IVF or ICSI (MNC) be a cost-effective alternative for controlled ovarian hyperstimulation IVF or ICSI (COH)? The comparison of simulated scenarios indicates that a strategy of three to six cycles of MNC with minimized medication is a cost-effective alternative for one

  19. Modified natural cycle versus controlled ovarian hyperstimulation IVF : a cost-effectiveness evaluation of three simulated treatment scenarios

    NARCIS (Netherlands)

    Groen, Henk; Tonch, Nino; Simons, Arnold H. M.; van der Veen, Fulco; Hoek, Annemieke; Land, Jolande A.

    2013-01-01

    STUDY QUESTION: Can modified natural cycle IVF or ICSI (MNC) be a cost-effective alternative for controlled ovarian hyperstimulation IVF or ICSI (COH)? SUMMARY ANSWER: The comparison of simulated scenarios indicates that a strategy of three to six cycles of MNC with minimized medication is a

  20. Analysis of fuel cycles with natural uranium, Phase I; Analiza gorivnih ciklusa sa prirodnim uranom, I faza

    Energy Technology Data Exchange (ETDEWEB)

    Stojadinovic, A; Zivkovic, Z; Raisic, N [Institute of Nuclear Sciences Boris Kidric, Laboratorija za fiziku i dinamiku reaktora, Vinca, Beograd (Serbia and Montenegro)

    1964-12-15

    This paper contains analyses of fuel cycles with natural uranium for the following cases: plutonium recycling is not done; recycling of plutonium and irradiated uranium with the condition of equal multiplication factor at the beginning of each cycle; and recycling of plutonium only.

  1. A randomized controlled, non-inferiority trial of modified natural versus artificial cycle for cryo-thawed embryo transfer

    NARCIS (Netherlands)

    Groenewoud, E. R.; Cohlen, B. J.; Al-Oraiby, A.; Brinkhuis, E. A.; Broekmans, F. J. M.; de Bruin, J. P.; van den Dool, G.; Fleisher, K.; Friederich, J.; Goddijn, M.; Hoek, A.; Hoozemans, D. A.; Kaaijk, E. M.; Koks, C. A. M.; Laven, J. S. E.; van der Linden, P. J. Q.; Manger, A. P.; Slappendel, E.; Spinder, T.; Kollen, B. J.; Macklon, N. S.

    2016-01-01

    Are live birth rates (LBRs) after artificial cycle frozen-thawed embryo transfer (AC-FET) non-inferior to LBRs after modified natural cycle frozen-thawed embryo transfer (mNC-FET)? AC-FET is non-inferior to mNC-FET with regard to LBRs, clinical and ongoing pregnancy rates (OPRs) but AC-FET does

  2. A randomized controlled, non-inferiority trial of modified natural versus artificial cycle for cryo-thawed embryo transfer

    NARCIS (Netherlands)

    Groenewoud, E. R.; Cohlen, B. J.; Al-Oraiby, A.; Brinkhuis, E. A.; Broekmans, F. J. M.; de Bruin, J. P.; van den Dool, G.; Fleisher, K.; Friederich, J.; Goddijn, M.; Hoek, A.; Hoozemans, D. A.; Kaaijk, E. M.; Koks, C. A. M.; Laven, J. S. E.; van der Linden, P. J. Q.; Manger, A. P.; Slappendel, E.; Spinder, T.; Kollen, B. J.; Macklon, N. S.

    STUDY QUESTION: Are live birth rates (LBRs) after artificial cycle frozen-thawed embryo transfer (AC-FET) non-inferior to LBRs after modified natural cycle frozen-thawed embryo transfer (mNC-FET)? SUMMARY ANSWER: AC-FET is non-inferior to mNC-FET with regard to LBRs, clinical and ongoing pregnancy

  3. A randomized controlled, non-inferiority trial of modified natural versus artificial cycle for cryo-thawed embryo transfer

    NARCIS (Netherlands)

    Groenewoud, E. R.; Cohlen, B. J.; Al-Oraiby, A.; Brinkhuis, E. A.; Broekmans, F. J M; De Bruin, J. P.; Van Den Dool, G.; Fleisher, K.; Friederich, J.; Goddijn, M.; Hoek, A.; Hoozemans, D. A.; Kaaijk, E. M.; Koks, C. A M; Laven, J. S E; Van Der Linden, P. J Q; Manger, A. P.; Slappendel, E.; Spinder, T.; Kollen, B. J.; Macklon, N. S.

    2016-01-01

    studyquestion: Are live birth rates (LBRs) after artificial cycle frozen-thawed embryo transfer (AC-FET) non-inferior to LBRs after modified natural cycle frozen-thawed embryo transfer (mNC-FET)? summaryanswer: AC-FET is non-inferior to mNC-FET with regard to LBRs, clinical and ongoing pregnancy

  4. 78 FR 70163 - Communication of Operational Information between Natural Gas Pipelines and Electric Transmission...

    Science.gov (United States)

    2013-11-22

    ... Street NE., Washington, DC 20426, (202) 502-8931, [email protected] . Anna Fernandez (Legal Information), Office of the General Counsel, 888 First Street NE., Washington, DC 20426, (202) 502-6682, anna.... Questions Posed by the Commission 100. A. Generator to Electric Transmission Operator 100. Communications 1...

  5. A specific association between facial disgust recognition and estradiol levels in naturally cycling women.

    Directory of Open Access Journals (Sweden)

    Sunjeev K Kamboj

    Full Text Available Subtle changes in social cognition are associated with naturalistic fluctuations in estrogens and progesterone over the course of the menstrual cycle. Using a dynamic emotion recognition task we aimed to provide a comprehensive description of the association between ovarian hormone levels and emotion recognition performance using a variety of performance metrics. Naturally cycling, psychiatrically healthy women attended a single experimental session during a follicular (days 7-13; n = 16, early luteal (days 15-19; n = 14 or late luteal phase (days 22-27; n = 14 of their menstrual cycle. Correct responses and reaction times to dynamic facial expressions were recorded and a two-high threshold analysis was used to assess discrimination and response bias. Salivary progesterone and estradiol were assayed and subjective measures of premenstrual symptoms, anxiety and positive and negative affect assessed. There was no interaction between cycle phase (follicular, early luteal, late luteal and facial expression (sad, happy, fearful, angry, neutral and disgusted on any of the recognition performance metrics. However, across the sample as a whole, progesterone levels were positively correlated with reaction times to a variety of facial expressions (anger, happiness, sadness and neutral expressions. In contrast, estradiol levels were specifically correlated with disgust processing on three performance indices (correct responses, response bias and discrimination. Premenstrual symptoms, anxiety and positive and negative affect were not associated with emotion recognition indices or hormone levels. The study highlights the role of naturalistic variations in ovarian hormone levels in modulating emotion recognition. In particular, progesterone seems to have a general slowing effect on facial expression processing. Our findings also provide the first behavioural evidence of a specific role for estrogens in the processing of disgust in humans.

  6. Microbial transmission from mothers with obesity or diabetes to infants: an innovative opportunity to interrupt a vicious cycle.

    Science.gov (United States)

    Soderborg, Taylor K; Borengasser, Sarah J; Barbour, Linda A; Friedman, Jacob E

    2016-05-01

    Maternal obesity and diabetes dramatically increase the long-term risk for obesity in the next generation, and pregnancy and lactation may be critical periods at which to aim primary prevention to break the obesity cycle. It is becoming increasingly clear that the gut microbiome in newborns and infants plays a significant role in gut health and therefore child development. Alteration of the early infant gut microbiome has been correlated with the development of childhood obesity and autoimmune conditions, including asthma, allergies and, more recently, type 1 diabetes. This is likely to be due to complex interactions between mode of delivery, antibiotic use, maternal diet, components of breastfeeding and a network of regulatory events involving both the innate and adaptive immune systems within the infant host. Each of these factors are critical for informing microbiome development and can affect immune signalling, toxin release and metabolic signals, including short-chain fatty acids and bile acids, that regulate appetite, metabolism and inflammation. In several randomised controlled trials, probiotics have been administered with the aim of targeting the microbiome during pregnancy to improve maternal and infant health but the findings have often been confounded by mode of delivery, antibiotic use, ethnicity, infant sex, maternal health and length of exposure. Understanding how nutritional exposure, including breast milk, affects the assembly and development of both maternal and infant microbial communities may help to identify targeted interventions during pregnancy and in infants born to mothers with obesity or diabetes to slow the transmission of obesity risk to the next generation. The aim of this review is to discuss influences on infant microbiota colonisation and the mechanism(s) underlying how alterations due to maternal obesity and diabetes may lead to increased risk of childhood obesity.

  7. CRE deliberation concerning balancing regime developments for the natural gas transmission network in France

    International Nuclear Information System (INIS)

    2006-06-01

    GRTgaz has presented a project of progressive changeover to a new market-based balancing system, according to the following principles: quantities of gas required to ensure transmission network balancing are purchased from or sold on the daily and intra-day market by transmission system operators (TSOs); a daily gas balancing price reflecting actual costs borne by every TSO is defined according to these purchases and sales; every day, each shipper residual position after use of the available flexibility and tolerance, is cleared off by transactions at the daily balancing gas price, under terms encouraging shippers to minimise their imbalance. In order to incorporate current development of the French market, which still has low liquidity, GRTgaz proposes to progressively develop the volume of its market transactions. Within this context, from 4 May to 6 June 2006, CRE organised a public consultation concerning balancing regime developments, a summary of which is presented. The last part concerns the CRE decisions. (A.L.B.)

  8. Naturally acquired antibody responses to recombinant Pfs230 and Pfs48/45 transmission blocking vaccine candidates.

    Science.gov (United States)

    Jones, Sophie; Grignard, Lynn; Nebie, Issa; Chilongola, Jaffu; Dodoo, Daniel; Sauerwein, Robert; Theisen, Michael; Roeffen, Will; Singh, Shrawan Kumar; Singh, Rajesh Kumar; Singh, Sanjay; Kyei-Baafour, Eric; Tetteh, Kevin; Drakeley, Chris; Bousema, Teun

    2015-07-01

    Pfs48/45 and Pfs230 are Plasmodium falciparum sexual stage proteins and promising malaria transmission-blocking vaccine candidates. Antibody responses against these proteins may be naturally acquired and target antigens may be under selective pressure. This has consequences for the future evaluation of vaccine immunogenicity and efficacy in populations naturally exposed to malaria. We determined naturally acquired antibody responses to the recombinant proteins Pfs48/45-10C and Pfs230-230CMB in children from three malaria endemic settings in Ghana, Tanzania and Burkina Faso. We also examined genetic polymorphisms in the P. falciparum gene pfs48/45. Antibody prevalence was 1.1-18.2% for 10C and 6.7-18.9% for 230CMB. In Burkina Faso we observed evidence of an age-dependent acquisition pattern for both 10C (p < 0.001) and 230CMB (p = 0.031). Membrane feeding assays on a separate dataset demonstrated an association between functional transmission reducing activity and antibody prevalence for both 10C (p = 0.017) and 230CMB (p = 0.049). 17 single nucleotide polymorphisms were found in pfs48/45 (from 126 samples), with 5 non-synonymous SNPs in the Pfs48/45 10C region. We conclude there are naturally acquired antibody responses to both vaccine candidates which have functional relevance by reducing the transmissibility of infected individuals. We identified genetic polymorphisms, in pfs48/45 which exhibited geographical specificity. Copyright © 2015 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  9. Bovine coronavirus in naturally andexperimentally exposed calves; viralshedding and the potential for transmission

    OpenAIRE

    Oma, Veslemøy Sunniva; Tråven, Madeleine; Alenius, S.; Myrmel, Mette; Stokstad, Maria

    2016-01-01

    Background Bovine coronavirus (BCoV) is a widely distributed pathogen, causing disease and economic losses in the cattle industry worldwide. Prevention of virus spread is impeded by a lack of basic knowledge concerning viral shedding and transmission potential in individual animals. The aims of the study were to investigate the duration and quantity of BCoV shedding in feces and nasal secretions related to clinical signs, the presence of virus in blood and tissues and to test the hypothesis t...

  10. Replacing single frozen-thawed euploid embryos in a natural cycle in ovulatory women may increase live birth rates compared to medicated cycles in anovulatory women.

    Science.gov (United States)

    Melnick, Alexis P; Setton, Robert; Stone, Logan D; Pereira, Nigel; Xu, Kangpu; Rosenwaks, Zev; Spandorfer, Steven D

    2017-10-01

    The goal of this study was to compare pregnancy outcomes between natural frozen embryo transfer (FET) cycles in ovulatory women and programmed FET cycles in anovulatory women after undergoing in vitro fertilization with preimplantation genetic screening (IVF-PGS). This was a retrospective cohort study performed at an academic medical center. Patients undergoing single FET IVF-PGS cycles between October 2011 and December 2014 were included. Patients were stratified by type of endometrial replacement: programmed cycles with estrogen/progesterone replacement and natural cycles. IVF-PGS with 24-chromosome screening was performed on all included patients. Those patients with euploid embryos had single embryo transfer in a subsequent FET. The primary study outcome was live birth/ongoing pregnancy rate. Secondary outcomes included implantation, biochemical pregnancy, and miscarriage rates. One hundred thirteen cycles met inclusion criteria: 65 natural cycles and 48 programmed cycles. The programmed FET group was younger (35.9 ± 4.5 vs. 37.5 ± 3.7, P = 0.03) and had a higher AMH (3.95 ± 4.2 vs. 2.37 ± 2.4, P = 0.045). The groups were similar for BMI, gravidity, parity, history of uterine surgery, and incidence of Asherman's syndrome. There was also no difference in embryo grade at biopsy or transfer, and proportion of day 5 and day 6 transfers. Implantation rates were higher in the natural FET group (0.66 ± 0.48 vs. 0.44 ± 0.50, P = 0.02). There was no difference in the rates of biochemical pregnancy or miscarriage. After controlling for age, live birth/ongoing pregnancy rate was higher in natural FETs with an adjusted odds ratio of 2.68 (95% CI 1.22-5.87). Natural FET in ovulatory women after IVF-PGS is associated with increased implantation and live birth rates compared to programmed FET in anovulatory women. Further investigation is needed to determine whether these findings hold true in other patient cohorts.

  11. The Antarctic Centennial Oscillation: A Natural Paleoclimate Cycle in the Southern Hemisphere That Influences Global Temperature

    Directory of Open Access Journals (Sweden)

    W. Jackson Davis

    2018-01-01

    Full Text Available We report a previously-unexplored natural temperature cycle recorded in ice cores from Antarctica—the Antarctic Centennial Oscillation (ACO—that has oscillated for at least the last 226 millennia. Here we document the properties of the ACO and provide an initial assessment of its role in global climate. We analyzed open-source databases of stable isotopes of oxygen and hydrogen as proxies for paleo-temperatures. We find that centennial-scale spectral peaks from temperature-proxy records at Vostok over the last 10,000 years occur at the same frequencies (±2.4% in three other paleoclimate records from drill sites distributed widely across the East Antarctic Plateau (EAP, and >98% of individual ACOs evaluated at Vostok match 1:1 with homologous cycles at the other three EAP drill sites and conversely. Identified ACOs summate with millennial periodicity to form the Antarctic Isotope Maxima (AIMs known to precede Dansgaard-Oeschger (D-O oscillations recorded in Greenland ice cores. Homologous ACOs recorded at the four EAP drill sites during the last glacial maximum appeared first at lower elevations nearest the ocean and centuries later on the high EAP, with latencies that exceed dating uncertainty >30-fold. ACO homologs at different drill sites became synchronous, however, during the warmer Holocene. Comparative spectral analysis suggests that the millennial-scale AIM cycle declined in period from 1500 to 800 years over the last 70 millennia. Similarly, over the last 226 millennia ACO repetition period (mean 352 years declined by half while amplitude (mean 0.67 °C approximately doubled. The period and amplitude of ACOs oscillate in phase with glacial cycles and related surface insolation associated with planetary orbital forces. We conclude that the ACO: encompasses at least the EAP; is the proximate source of D-O oscillations in the Northern Hemisphere; therefore affects global temperature; propagates with increased velocity as temperature

  12. Plio-Pleistocene imprint of natural climate cycles in marine sediments

    Energy Technology Data Exchange (ETDEWEB)

    Lebreiro, S. M.

    2013-06-01

    The response of Earth to natural climate cyclicity is written in marine sediments. The Earth is a complex system, as is climate change determined by various modes, frequency of cycles, forcings, boundary conditions, thresholds, and tipping elements. Oceans act as climate change buffers, and marine sediments provide archives of climate conditions in the Earths history. To read climate records they must be well-dated, well-calibrated and analysed at high-resolution. Reconstructions of past climates are based on climate variables such as atmospheric composition, temperature, salinity, ocean productivity and wind, the nature and quality which are of the utmost importance. Once the palaeoclimate and palaeoceanographic proxy-variables of past events are well documented, the best results of modelling and validation, and future predictions can be obtained from climate models. Neither the mechanisms for abrupt climate changes at orbital, millennial and multi-decadal time scales nor the origin, rhythms and stability of cyclicity are as yet fully understood. Possible sources of cyclicity are either natural in the form of internal ocean-atmosphere-land interactions or external radioactive forcing such as solar irradiance and volcanic activity, or else anthropogenic. Coupling with stochastic resonance is also very probable. I provide here, an overview of the cyclicity affecting the Earth on various time scales focussing upon the Plio-Pleistocene and Holocene epochs, together with a compilation of some of the key questions under debate, and a number of representative works that illustrate cyclicity in marine sediments. (Author)

  13. Naturally acquired antibody responses to recombinant Pfs230 and Pfs48/45 transmission blocking vaccine candidates

    DEFF Research Database (Denmark)

    Jones, Sophie; Grignard, Lynn; Nebie, Issa

    2015-01-01

    for the future evaluation of vaccine immunogenicity and efficacy in populations naturally exposed to malaria. METHODS: We determined naturally acquired antibody responses to the recombinant proteins Pfs48/45-10C and Pfs230-230CMB in children from three malaria endemic settings in Ghana, Tanzania and Burkina Faso......OBJECTIVES: Pfs48/45 and Pfs230 are Plasmodium falciparum sexual stage proteins and promising malaria transmission-blocking vaccine candidates. Antibody responses against these proteins may be naturally acquired and target antigens may be under selective pressure. This has consequences....... We also examined genetic polymorphisms in the P. falciparum gene pfs48/45. RESULTS: Antibody prevalence was 1.1-18.2% for 10C and 6.7-18.9% for 230CMB. In Burkina Faso we observed evidence of an age-dependent acquisition pattern for both 10C (p assays...

  14. Frozen-thawed embryo transfer in a natural or mildly hormonally stimulated cycle in women with regular ovulatory cycles: a RCT.

    Science.gov (United States)

    Peeraer, Karen; Couck, Isabelle; Debrock, Sophie; De Neubourg, Diane; De Loecker, Peter; Tomassetti, Carla; Laenen, Annouschka; Welkenhuysen, Myriam; Meeuwis, Luc; Pelckmans, Sofie; Meuleman, Christel; D'Hooghe, Thomas

    2015-11-01

    Can ovarian stimulation with low dose hMG improve the implantation rate (IR) per frozen-thawed embryo transferred (FET) when compared with natural cycle in an FET programme in women with a regular ovulatory cycle? Both IR and live birth rate (LBR) per FET were similar in the group with mild ovarian stimulation and the natural cycle group. Different cycle regimens for endometrial preparation are used prior to FET: spontaneous ovulatory cycles, cycles with artificial endometrial preparation using estrogen and progesterone hormones, and cycles stimulated with gonadotrophins or clomiphene citrate. At present, it is not clear which regimen results in the highest IR or LBR. More specifically, there are no RCTs in ovulatory women comparing reproductive outcome after FET during a natural cycle and during a hormonally stimulated cycle. A total of 410 women scheduled for FET during 579 cycles (December 2003-September 2013) were enrolled in an open-label RCT to natural cycle (NC FET group, n = 291) or to a cycle hormonally stimulated with s.c. gonadotrophins (hMG FET group, 37.5-75 IU per day, n = 288). A total of 672 embryos were transferred during 434 cycles (332 embryos and 213 cycles in the NC FET group; 340 embryos and 221 cycles in the hMG FET group). Assuming a = 0.05 and 80% power, it was calculated that 219 frozen-thawed embryos were required for transfer in each group to demonstrate a difference of 10% in IR. Women were eligible according to the following inclusion criteria: regular ovulatory cycle, female age ≥21 years and ≤45 years, informed consent. FET cycles with preimplantation genetic screening were excluded. The primary outcome was IR per embryo transferred. Secondary outcomes included IR with fetal heart beat (FHB), LBR per embryo transferred and endometrial thickness on the day of hCG administration. Statistical analysis was by intention to treat and controlled for the presence of multiple measures, as eligible women could be randomized in more than

  15. Impacts on human health from the coal and nuclear fuel cycles and other technologies associated with electric power generation and transmission

    International Nuclear Information System (INIS)

    Radford, E.P.

    1980-01-01

    Major public health impacts of electric power generation and transmission associated with the nuclear fuel cycle and with coal use are evaluated. Only existing technology is evaluated. The only health effects of concern are those leading to definable human disease and injury. Health effects are scaled to a nominal 1000 Megawatt (electric) plant fueled by either option. Comparison of the total health effects to the general public gives: nuclear, 0.03 to 0.05 major health effects per 1000 MWe per year; coal, 0.7 to 3.7 per 1000 MWe per year. Thus for the general public the health risks from the coal cycle are about 50 times greater than for the nuclear cycle. Health effects to workers in the industry are currently quite high. For the nuclear cycle, 4.6 to 5.1 major health impacts per 1000 MWe per year; for coal, 6.5 to 10.9. The two-fold greater risk for the coal cycle is primarily due to high injury rates in coal miners. There is no evidence that electrical transmission contributes any health effects to the general public, except for episodes where broken power lines come in contact with people. For power line workers, the risk is estimated at 0.1 serious injury per 1000 MWe per year

  16. Process modelling and techno-economic analysis of natural gas combined cycle integrated with calcium looping

    Directory of Open Access Journals (Sweden)

    Erans María

    2016-01-01

    Full Text Available Calcium looping (CaL is promising for large-scale CO2 capture in the power generation and industrial sectors due to the cheap sorbent used and the relatively low energy penalties achieved with this process. Because of the high operating temperatures the heat utilisation is a major advantage of the process, since a significant amount of power can be generated from it. However, this increases its complexity and capital costs. Therefore, not only the energy efficiency performance is important for these cycles, but also the capital costs must be taken into account, i.e. techno-economic analyses are required in order to determine which parameters and configurations are optimal to enhance technology viability in different integration scenarios. In this study the integration scenarios of CaL cycles and natural gas combined cycles (NGCC are explored. The process models of the NGCC and CaL capture plant are developed to explore the most promising scenarios for NGCC-CaL integration with regards to efficiency penalties. Two scenarios are analysed in detail, and show that the system with heat recovery steam generator (HRSG before and after the capture plant exhibited better performance of 49.1% efficiency compared with that of 45.7% when only one HRSG is located after the capture plant. However, the techno-economic analyses showed that the more energy efficient case, with two HRSGs, implies relatively higher cost of electricity (COE, 44.1€/MWh, when compared to that of the reference plant system (33.1€/MWh. The predicted cost of CO2 avoided for the case with two HRSGS is 29.3 €/ton CO2.

  17. Future ocean hypercapnia driven by anthropogenic amplification of the natural CO2 cycle

    Science.gov (United States)

    McNeil, Ben I.; Sasse, Tristan P.

    2016-01-01

    High carbon dioxide (CO2) concentrations in sea-water (ocean hypercapnia) can induce neurological, physiological and behavioural deficiencies in marine animals. Prediction of the onset and evolution of hypercapnia in the ocean requires a good understanding of annual variations in oceanic CO2 concentration, but there is a lack of relevant global observational data. Here we identify global ocean patterns of monthly variability in carbon concentration using observations that allow us to examine the evolution of surface-ocean CO2 levels over the entire annual cycle under increasing atmospheric CO2 concentrations. We predict that the present-day amplitude of the natural oscillations in oceanic CO2 concentration will be amplified by up to tenfold in some regions by 2100, if atmospheric CO2 concentrations continue to rise throughout this century (according to the RCP8.5 scenario of the Intergovernmental Panel on Climate Change). The findings from our data are broadly consistent with projections from Earth system climate models. Our predicted amplification of the annual CO2 cycle displays distinct global patterns that may expose major fisheries in the Southern, Pacific and North Atlantic oceans to hypercapnia many decades earlier than is expected from average atmospheric CO2 concentrations. We suggest that these ocean ‘CO2 hotspots’ evolve as a combination of the strong seasonal dynamics of CO2 concentration and the long-term effective storage of anthropogenic CO2 in the oceans that lowers the buffer capacity in these regions, causing a nonlinear amplification of CO2 concentration over the annual cycle. The onset of ocean hypercapnia (when the partial pressure of CO2 in sea-water exceeds 1,000 micro-atmospheres) is forecast for atmospheric CO2 concentrations that exceed 650 parts per million, with hypercapnia expected in up to half the surface ocean by 2100, assuming a high-emissions scenario (RCP8.5). Such extensive ocean hypercapnia has detrimental implications for

  18. Optimal capacity design of LID facility for conserving natural water cycle and its sensitivity analysis

    Science.gov (United States)

    Lee, O.; Choi, J.; Lee, J.; Kim, S.

    2017-12-01

    Since the 20th century, urbanization has resulted in increased impermeable land surface and reduced infiltration capacity in catchment scale. Especially, when agriculture area or forest area would be developed into urban area, it can cause more runoff in the same climate condition. Such urbanization causes problems such as changes in hydrological cycle and ecosystem disturbance. Various methods have been proposed worldwide to reduce the impact of such urbanization. Among the various strategies, the low-impact development is a development strategy that aims to return to pre-development state by minimizing the change of the hydrological cycle due to urbanization. In this strategy, the infiltration and/or surface storage of stormwater runoff can be increased through the installation of various facilities. In this study, a facility capacity design strategy is proposed to return into the natural water cycle through the installation of various LID facilities. This is accomplished by determining the optimal LID facility design capacity through which flow duration curves remain the same before and after urban development. For this purpose, EPA-SWMM is constructed with a part of Busan Metropolitan City Noksan Industrial Complex as a virtual processing area. Under the various land-use scenarios, the optimum design capacity of various LID facilities capable of retaining the flow duration curve before and after development is determined. In addition, the sensitivity of the optimal design capacity of LID facilities is analyzed according to the design specifications of various LID facilities, the local rainfall characteristics, and the size of the treatment area. Acknowledgement This research was supported by a grant (2016000200002) from Public Welfare Technology Development Program funded by Ministry of Environment of Korean government.

  19. Thermal enhancement of charge and discharge cycles for adsorbed natural gas storage

    KAUST Repository

    Rahman, Kazi Afzalur

    2011-07-01

    The usage of adsorbed natural gas (ANG) storage is hindered by the thermal management during the adsorption and desorption processes. An effective thermal enhancement is thus essential for the development of the ANG technology and the motivation for this study is the investigation of a gas storage system with internal thermal control. We employed a fin-tube type heat exchanger that is placed in a pressurized cylinder. A distributed-parameter model is used for the theoretical modeling and simulations are conducted at assorted charging and discharging conditions. These studies included the transient thermal behaviours of the elements within the ANG-charged cylinder and parameters such as pressure and temperature profiles of adsorbent have been obtained during charge and discharge cycles, and results are compared with a conventional compressed methane vessel. © 2011 Elsevier Ltd. All rights reserved.

  20. A study of cycling of 90Sr in a natural forest on the Canadian Shield

    International Nuclear Information System (INIS)

    Cooper, E.L.; Rahman, M.M.

    1994-01-01

    A study of the cycling of 90 Sr in a natural forest growing over a shallow zone of low-level 90 Sr-contaminated groundwater was carried out at the Chalk River Laboratories of AECL Research. The contamination is about 1 m below the surface under most of the site and evidence from earlier studies indicates that 90 Sr is being brought to the surface by deeper rooting trees. Once it is on the surface, the 90 Sr becomes available for uptake by other biota in the area. The study was initiated by taking an inventory of 90 Sr in various compartments including: soil, leaf litter, wood and foliage. Samples of leaf fall, stemflow and throughfall were also collected in order to estimate the relative importance of these mechanisms in cycling 90 Sr to the forest floor. Most of the 90 Sr on or near the surface is in the leaf litter and the top 8 cm of soil, as well as in the vegetation. Downward migration of 90 Sr through the unsaturated zone is slow. This may be due to strong retention by the soil; however, it could also be due to recycling of 90 Sr by the vegetation. The accumulated inventory in the leaf litter is about equal to the input from leaf fall over a period of 3 years

  1. Evidence of vertical transmission and tissue tropism of Streptococcosis from naturally infected red tilapia (Oreochromis spp.

    Directory of Open Access Journals (Sweden)

    Padmaja Jayaprasad Pradeep

    2016-05-01

    Full Text Available Streptococcosis is a highly problematic disease in the aquaculture of freshwater fishes, especially for tilapia. The possibility of vertical transmission of streptococcosis and the pattern of tissue tropism of this pathogen in various organs was examined in red tilapia (Oreochromis sp.. Healthy broodstock without any clinical signs of Streptococcus spp. were selected from a farm earlier reported to have the disease and a total of 10 pairs were forced spawned to provide samples of gametes and progeny for pathogen testing. A colorimetric LAMP assay was used to confirm whether the bacterial pathogens Streptococcus. agalactiae and Streptococcus. iniae was present in samples of milt, unfertilized eggs, fertilized eggs, and offspring at various stages of development, as well as internal organs of broodstock (reproductive organs, gill, liver, spleen, kidney and brain as well as samples of water from culture systems. The majority of samples of milt (9/10 and unfertilized eggs (7/10 collected from the broodstock were infected with S. iniae at the time of spawning and was transmitted to all of their offspring. Nevertheless, when the same samples of gametes were analyzed for S. agalactiae, they were all found to be negative but the pathogen was found to be present in some 10-day-old larval offspring (4/10. However, when the pathogenic presence was analyzed from the reproductive organs of the parents, both S. agalactiae (11/20 and S. iniae (18/20 bacterium were common. Although, all broodstock were asymptomatic, almost all broodstock harboured the bacteria in many organs. Confirmation of vertical transmission of streptococcosis in tilapia means that intergenerational break cannot be used as a reliable and simple means of reducing or eliminating the prevalence of these difficult pathogens in aquaculture stock. Keywords: Tilapia, Vertical transmission, Specific pathogen free, Streptococcus, Tissue tropism

  2. Cross-border trading and transmission networks. The natural gas experience

    International Nuclear Information System (INIS)

    Zavattoni, G.

    1992-01-01

    The volume and sources of gas imports to Europe and cross-border trading regulations for gas imports into and within Europe are outlined. The import of gas from Algeria to Italy is presented as a case study. It deals with the purchase contract, transmission through Tunisia, the crossing of the Strait of Sicily and transportation within Italy. The EC Transit Directive, the Draft Directive(s) on third party access and the impact of the directives on the gas market are then discussed. (UK)

  3. Natural compounds' activity against cancer stem-like or fast-cycling melanoma cells.

    Directory of Open Access Journals (Sweden)

    Malgorzata Sztiller-Sikorska

    Full Text Available BACKGROUND: Accumulating evidence supports the concept that melanoma is highly heterogeneous and sustained by a small subpopulation of melanoma stem-like cells. Those cells are considered as responsible for tumor resistance to therapies. Moreover, melanoma cells are characterized by their high phenotypic plasticity. Consequently, both melanoma stem-like cells and their more differentiated progeny must be eradicated to achieve durable cure. By reevaluating compounds in heterogeneous melanoma populations, it might be possible to select compounds with activity not only against fast-cycling cells but also against cancer stem-like cells. Natural compounds were the focus of the present study. METHODS: We analyzed 120 compounds from The Natural Products Set II to identify compounds active against melanoma populations grown in an anchorage-independent manner and enriched with cells exerting self-renewing capacity. Cell viability, cell cycle arrest, apoptosis, gene expression, clonogenic survival and label-retention were analyzed. FINDINGS: Several compounds efficiently eradicated cells with clonogenic capacity and nanaomycin A, streptonigrin and toyocamycin were effective at 0.1 µM. Other anti-clonogenic but not highly cytotoxic compounds such as bryostatin 1, siomycin A, illudin M, michellamine B and pentoxifylline markedly reduced the frequency of ABCB5 (ATP-binding cassette, sub-family B, member 5-positive cells. On the contrary, treatment with maytansine and colchicine selected for cells expressing this transporter. Maytansine, streptonigrin, toyocamycin and colchicine, even if highly cytotoxic, left a small subpopulation of slow-dividing cells unaffected. Compounds selected in the present study differentially altered the expression of melanocyte/melanoma specific microphthalmia-associated transcription factor (MITF and proto-oncogene c-MYC. CONCLUSION: Selected anti-clonogenic compounds might be further investigated as potential adjuvants

  4. Floating microbial fuel cells as energy harvesters for signal transmission from natural water bodies

    Science.gov (United States)

    Schievano, Andrea; Colombo, Alessandra; Grattieri, Matteo; Trasatti, Stefano P.; Liberale, Alessandro; Tremolada, Paolo; Pino, Claudio; Cristiani, Pierangela

    2017-02-01

    A new type of floating microbial fuel cell (fMFC) was developed for power supply of remote environmental sensors and data transmission. Ten operating fMFCs generated a cell potential in the range 100-800 mV depending on the external resistance applied. Power production peaked around 3-3.5 mW (power density of 22-28 mW m-2 cathode) after about 20-30 days of start-up period. The average of daily electrical energy harvested ranged between 10 and 35 mWh/d. Long-term performances were ensured in the presence of dense rice plants (Oryza Sativa). A power management system, based on a step-up DC/DC converter and a low-power data transmission system via SIGFOX™ technology, have been set up for the fMFCs. The tested fMFCs systems allowed to: i) harvest produced energy, ii) supply electronic devices (intermittent LED-light and a buzzer); iii) transmit remote data at low speed (three message of 12 bites each, in 6 s). Several 'floating garden' MFCs were set in the context of demonstrative events at EXPO2015 world exposition held in Milan between May-October 2015. Some of the 'floating garden' MFCs were operating for more than one year.

  5. Does the use of gonadotropin-releasing hormone antagonists in natural IVF cycles for poor responder patients cause more harm than benefit?

    Science.gov (United States)

    Aksoy, Senai; Yakin, Kayhan; Seyhan, Ayse; Oktem, Ozgur; Alatas, Cengiz; Ata, Baris; Urman, Bulent

    2016-06-01

    Poor ovarian response to controlled ovarian stimulation (COS) is one of the most critical factors that substantially limits the success of assisted reproduction techniques (ARTs). Natural and modified natural cycle IVF are two options that could be considered as a last resort. Blocking gonadotropin-releasing hormone (GnRH) actions in the endometrium via GnRH receptor antagonism may have a negative impact on endometrial receptivity. We analysed IVF outcomes in 142 natural (n = 30) or modified natural (n = 112) IVF cycles performed in 82 women retrospectively. A significantly lower proportion of natural cycles reached follicular aspiration compared to modified natural cycles (56.7% vs. 85.7%, p cycles ending in embryo transfer (26.7% vs. 44.6%) was not statistically significant between natural cycle and modified natural IVF cycles. Clinical pregnancy (6.7% vs. 7.1%) and live birth rates per initiated cycle (6.7% vs. 5.4%) were similar between the two groups. Notably, the implantation rate was slightly lower in modified natural cycles (16% vs. 25%, p > 0.05). There was a trend towards higher clinical pregnancy (25% vs. 16%) and live birth (25% vs. 12%) rates per embryo transfer in natural cycles compared to modified natural cycles, but the differences did not reach statistical significance.

  6. Performance of an Otto cycle motor with natural gas direct injection; Desempenho de um motor ciclo Otto com injecao direta de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Cleiton Rubens Formiga

    1997-07-01

    A Otto cycle engine with natural gas direct injection, during the inlet stroke, was submitted to runs with full power in a Foucaut dynamometer. The results obtained show a increase in the volumetric efficiency of the engine with natural gas direct injection when compared with natural gas injection applied in the inlet manifold, upstream of the throttle butterfly. In the conversion to natural gas direct injection, the technical characteristics were not changed. A kit for natural gas direct injection, with electronic management was located on the cylinder head of the test engine. Maintaining the pressure constant in the natural gas fuel line, using a reduction valve, the mass of fuel injected into the cylinder was regulated, varying the opening time of the solenoid valve fuel injector. Engine performance data is compared, emphasizing the factors that contribute to this increase in relative volumetric efficiency. Modifications are made to maximize the power of the engine with natural gas direct injection. (author)

  7. Prevalence, genetic identity and vertical transmission of Babesia microti in three naturally infected species of vole, Microtus spp. (Cricetidae).

    Science.gov (United States)

    Tołkacz, Katarzyna; Bednarska, Małgorzata; Alsarraf, Mohammed; Dwużnik, Dorota; Grzybek, Maciej; Welc-Falęciak, Renata; Behnke, Jerzy M; Bajer, Anna

    2017-02-06

    Vertical transmission is one of the transmission routes for Babesia microti, the causative agent of the zoonotic disease, babesiosis. Congenital Babesia invasions have been recorded in laboratory mice, dogs and humans. The aim of our study was to determine if vertical transmission of B. microti occurs in naturally-infected reservoir hosts of the genus Microtus. We sampled 124 common voles, Microtus arvalis; 76 root voles, M. oeconomus and 17 field voles, M. agrestis. In total, 113 embryos were isolated from 20 pregnant females. Another 11 pregnant females were kept in the animal house at the field station in Urwitałt until they had given birth and weaned their pups (n = 62). Blood smears and/or PCR targeting the 550 bp 18S rRNA gene fragment were used for the detection of B. microti. Selected PCR products, including isolates from females/dams and their embryos/pups, were sequenced. Positive PCR reactions were obtained for 41% (89/217) of the wild-caught voles. The highest prevalence of B. microti was recorded in M. arvalis (56/124; 45.2%), then in M. oeconomus (30/76; 39.5%) and the lowest in M. agrestis (3/17; 17.7%). Babesia microti DNA was detected in 61.4% (27/44) of pregnant females. Vertical transmission was confirmed in 81% (61/75) of the embryos recovered from Babesia-positive wild-caught pregnant females. The DNA of B. microti was detected in the hearts, lungs and livers of embryos from 98% of M. arvalis, 46% of M. oeconomus and 0% of M. agrestis embryos from Babesia-positive females. Of the pups born in captivity, 90% were born to Babesia-positive dams. Babesia microti DNA was detected in 70% (35/50) of M. arvalis and 83% (5/6) of M. oeconomus pups. Congenitally acquired infections had no impact on the survival of pups over a 3-week period post partum. Among 97 B. microti sequences, two genotypes were found. The IRU1 genotype (Jena-like) was dominant in wild-caught voles (49/53; 92%), pregnant females (9/11; 82%) and dams (3/5; 60%). The IRU2

  8. Impacts on human health from the coal and nuclear fuel cycles and other technologies associated with electric power generation and transmission

    International Nuclear Information System (INIS)

    Radford, E.P.

    1980-07-01

    The report evaluates major public health impacts of electric power generation and transmission associated with the nuclear fuel cycle and with coal use. Only existing technology is evaluated. For the nuclear cycle, effects of future use of fuel reprocessing and long-term radioactive waste disposal are briefly considered. The health effects of concern are those leading to definable human disease and injury. Health effects are scaled to numbers of persons and activities associated with a nominal 1000-megawatt electric plant fueled by either option. Comparison of the total health effects to the general public shows that the health risks from the coal cycle are about 50 times greater than for the nuclear cycle (coal, 0.7-3.7 major health effects per 1000 MWe per year; nuclear, 0.03-0.05 per 1000 MWe per year). For workers, these rates are higher. No evidence is found that electrical transmission contributes any health effects to the general public, except when broken power lines come in contact with people

  9. Presence and patterns of alkaline phosphatase activity and phosphorus cycling in natural riparian zones under changing nutrient conditions

    OpenAIRE

    Peifang Wang; Lingxiao Ren; Chao Wang; Jin Qian; Jun Hou

    2014-01-01

    Phosphorus (P) is an important limiting nutrient in aquatic ecosystems and knowledge of P cycling is fundamental for reducing harmful algae blooms and other negative effects in water. Despite their importance, the characteristics of P cycling under changing nutrient conditions in shallow lakes were poorly investigated. In this study, in situ incubation experiments were conducted in a natural riparian zone in the main diversion channel used for water transfer into Lake Taihu (Wangyu River). Va...

  10. Risk-targeted safety distance of reinforced concrete buildings from natural-gas transmission pipelines

    International Nuclear Information System (INIS)

    Russo, Paola; Parisi, Fulvio

    2016-01-01

    Natural-gas pipeline accidents mostly result in major damage even to buildings located far away. Therefore, proper safety distances should be observed in land use planning to ensure target safety levels for both existing and new buildings. In this paper, a quantitative risk assessment procedure is presented for the estimation of the annual probability of direct structural damage to reinforced concrete buildings associated with high-pressure natural-gas pipeline explosions. The procedure is based on Monte Carlo simulation and takes into account physical features of blast generation and propagation, as well as damage to reinforced concrete columns. The natural-gas jet release process and the flammable cloud size are estimated through SLAB one-dimensional integral model incorporating a release rate model. The explosion effects are evaluated by a Multi-Energy Method. Damage to reinforced concrete columns is predicted by means of pressure–impulse diagrams. The conditional probability of damage was estimated at multiple pressure–impulse levels, allowing blast fragility surfaces to be derived at different performance limit states. Finally, blast risk was evaluated and allowed the estimation of minimum pipeline-to-building safety distances for risk-informed urban planning. The probabilistic procedure presented herein may be used for performance-based design/assessment of buildings and to define the path of new natural-gas pipeline networks. - Highlights: • The safety of buildings against blast loads due to pipeline accidents is assessed. • A probabilistic risk assessment procedure is presented for natural-gas pipelines. • The annual risk of collapse of reinforced concrete building columns is evaluated. • Monte Carlo simulation was carried out considering both pipeline and column features. • A risk-targeted safety distance is proposed for blast strength class 9.

  11. Modified natural cycle for embryo transfer using frozen-thawed blastocysts: A satisfactory option.

    Science.gov (United States)

    Le, Quoc V; Abhari, Sina; Abuzeid, Omar M; DeAnna, Jennifer; Satti, Mohamed A; Abozaid, Tarek; Khan, Iqbal; Abuzeid, Mostafa I

    2017-06-01

    To describe pregnancy outcomes of frozen-thawed blastocysts cycles using modified natural cycle frozen embryo transfers (NC-FET) and down-regulated hormonally controlled frozen embryo transfers (HC-FET) protocols. This retrospective cohort study included all patients undergoing either modified NC-FET or down-regulated HC-FET using frozen-thawed day 5 embryos. Cycles with donor blastocysts were excluded. Four hundred twenty eight patients underwent a total of 493 FET cycles. Patients with regular menses and evidence of ovulation underwent modified NC-FET. These patients were given hCG 10,000 IU IM on the day of LH-surge. Vaginal progesterone (P4) was started two days later and blastocyst transfer was planned seven days after detecting the LH surge. Anovulatory patients and some ovulatory patients underwent down-regulated HC-FET. These patients were placed on medroxy-progesterone acetate (10mg) for 10days to bring on menses and were also given a half-dose of GnRH-agonist (GnRH-a) on the third day of medroxy-progesterone acetate. Exogenous estradiol was initiated on the third day of menses. Once serum E2 levels reached >500pg/mL and endometrial lining reached >8mm, intramuscular (IM) P4 in oil was administered. Blastocyst FET was planned 6days after initiating P4. The primary outcomes included clinical pregnancy and delivery rates. There were 197 patients in the modified NC-FET protocol and 181 in the down-regulated HC-FET protocol. Mean age (years), day-3 FSH levels (mIU/mL) and percentage of patients with male factor infertility were significantly higher and mean BMI (kg/m 2 ) was significantly lower in modified NC-FET compared to HC-FET, respectively. Analysis of the first cycle pregnancy outcomes revealed no significant differences in clinical pregnancy rate (54.3% vs. 52.5%) and delivery rate (47.2% vs. 43.6%) between modified NC-FET and HC-FET. Logistic regression analysis showed age (OR=0.939, 95% CI 0.894-0.989, p=0.011), number of blastocysts transferred (OR

  12. Nature, Nurture and Evolution of Intra-Species Variation in Mosquito Arbovirus Transmission Competence

    OpenAIRE

    Tabachnick, Walter J.

    2013-01-01

    Mosquitoes vary in their competence or ability to transmit arthropod-borne viruses (arboviruses). Many arboviruses cause disease in humans and animals. Identifying the environmental and genetic causes of variation in mosquito competence for arboviruses is one of the great challenges in public health. Progress identifying genetic (nature) and environmental (nurture) factors influencing mosquito competence for arboviruses is reviewed. There is great complexity in the various traits that compris...

  13. A Naturally Transmitted Epitheliotropic Polyomavirus Pathogenic in Immunodeficient Rats: Characterization, Transmission, and Preliminary Epidemiologic Studies.

    Science.gov (United States)

    Besch-Williford, Cynthia; Pesavento, Patricia; Hamilton, Shari; Bauer, Beth; Kapusinszky, Beatrix; Phan, Tung; Delwart, Eric; Livingston, Robert; Cushing, Susan; Watanabe, Rie; Levin, Stephen; Berger, Diana; Myles, Matthew

    2017-07-01

    We report the identification, pathogenesis, and transmission of a novel polyomavirus in severe combined immunodeficient F344 rats with null Prkdc and interleukin 2 receptor gamma genes. Infected rats experienced weight loss, decreased fecundity, and mortality. Large basophilic intranuclear inclusions were observed in epithelium of the respiratory tract, salivary and lacrimal glands, uterus, and prostate gland. Unbiased viral metagenomic sequencing of lesioned tissues identified a novel polyomavirus, provisionally named Rattus norvegicus polyomavirus 2 (RatPyV2), which clustered with Washington University (WU) polyomavirus in the Wuki clade of the Betapolyomavirus genus. In situ hybridization analyses and quantitative polymerase chain reaction (PCR) results demonstrated viral nucleic acids in epithelium of respiratory, glandular, and reproductive tissues. Polyomaviral disease was reproduced in Foxn1 rnu nude rats cohoused with infected rats or experimentally inoculated with virus. After development of RatPyV2-specific diagnostic assays, a survey of immune-competent rats from North American research institutions revealed detection of RatPyV2 in 7 of 1,000 fecal samples by PCR and anti-RatPyV2 antibodies in 480 of 1,500 serum samples. These findings suggest widespread infection in laboratory rat populations, which may have profound implications for established models of respiratory injury. Additionally, RatPyV2 infection studies may provide an important system to investigate the pathogenesis of WU polyomavirus diseases of man.

  14. A physiological time analysis of the duration of the gonotrophic cycle of Anopheles pseudopunctipennis and its implications for malaria transmission in Bolivia

    Directory of Open Access Journals (Sweden)

    Quispe Vicente

    2008-07-01

    Full Text Available Abstract Background The length of the gonotrophic cycle varies the vectorial capacity of a mosquito vector and therefore its exact estimation is important in epidemiological modelling. Because the gonotrophic cycle length depends on temperature, its estimation can be satisfactorily computed by means of physiological time analysis. Methods A model of physiological time was developed and calibrated for Anopheles pseudopunctipennis, one of the main malaria vectors in South America, using data from laboratory temperature controlled experiments. The model was validated under varying temperatures and could predict the time elapsed from blood engorgement to oviposition according to the temperature. Results In laboratory experiments, a batch of An. pseudopunctipennis fed at the same time may lay eggs during several consecutive nights (2–3 at high temperature and > 10 at low temperature. The model took into account such pattern and was used to predict the range of the gonotrophic cycle duration of An. pseudopunctipennis in four characteristic sites of Bolivia. It showed that the predicted cycle duration for An. pseudopunctipennis exhibited a seasonal pattern, with higher variances where climatic conditions were less stable. Predicted mean values of the (minimum duration ranged from 3.3 days up to > 10 days, depending on the season and the geographical location. The analysis of ovaries development stages of field collected biting mosquitoes indicated that the phase 1 of Beklemishev might be of significant duration for An. pseudopunctipennis. The gonotrophic cycle length of An. pseudopunctipennis correlates with malaria transmission patterns observed in Bolivia which depend on locations and seasons. Conclusion A new presentation of cycle length results taking into account the number of ovipositing nights and the proportion of mosquitoes laying eggs is suggested. The present approach using physiological time analysis might serve as an outline to other

  15. Experimental demonstration of 608Gbit/s short reach transmission employing half-cycle 16QAM Nyquist-SCM signal and direct detection with 25Gbps EML.

    Science.gov (United States)

    Zhong, Kangping; Zhou, Xian; Wang, Yiguang; Wang, Liang; Yuan, Jinhui; Yu, Changyuan; Lau, Alan Pak Tao; Lu, Chao

    2016-10-31

    In this paper, we experimentally demonstrated an IM/DD short reach transmission system with a total capacity of 608Gbit/s (net capacity of 565.4Gbit/s exclude 7% FEC overhead) employing half-cycle 16QAM Nyquist-SCM signal and 25Gbps EML at O band. Direct detection-faster than Nyquist (DD-FTN) technique was employed to compensate channel impairments. Number of taps of DD-LMS and tap coefficient of post filter in DD-FTN were experimentally studied for different baud rates. Single-lane 152Gbit/s transmission over 10km of SSMF was experimentally demonstrated. Employing a 4-lanes LAN-WDM architecture, a total capacity of 608Gbit/s transmission over 2km was successfully achieved with a receiver sensitivity lower than -4dBm. To the best of authors' knowledge, this is the highest reported baud rate of half-cycle 16QAM Nyquist-SCM signal and the highest bit rate employing IM/DD and 25Gbps EML in a four lanes LAN-WDM architecture for short reach systems in the O band.

  16. Enhanced CANDU6: Reactor and fuel cycle options - Natural uranium and beyond

    International Nuclear Information System (INIS)

    Ovanes, M.; Chan, P. S. W.; Mao, J.; Alderson, N.; Hopwood, J. M.

    2012-01-01

    The Enhanced CANDU 6 R (ECo R ) is the updated version of the well established CANDU 6 family of units incorporating improved safety characteristics designed to meet or exceed Generation III nuclear power plant expectations. The EC6 retains the excellent neutron economy and fuel cycle flexibility that are inherent in the CANDU reactor design. The reference design is based on natural uranium fuel, but the EC6 is also able to utilize additional fuel options, including the use of Recovered Uranium (RU) and Thorium based fuels, without requiring major hardware upgrades to the existing control and safety systems. This paper outlines the major changes in the EC6 core design from the existing C6 design that significantly enhance the safety characteristics and operating efficiency of the reactor. The use of RU fuel as a transparent replacement fuel for the standard 37-el NU fuel, and several RU based advanced fuel designs that give significant improvements in fuel burnup and inherent safety characteristics are also discussed in the paper. In addition, the suitability of the EC6 to use MOX and related Pu-based fuels will also be discussed. (authors)

  17. A method of quantitative risk assessment for transmission pipeline carrying natural gas

    International Nuclear Information System (INIS)

    Jo, Young-Do; Ahn, Bum Jong

    2005-01-01

    Regulatory authorities in many countries are moving away from prescriptive approaches for keeping natural gas pipelines safe. As an alternative, risk management based on a quantitative assessment is being considered to improve the level of safety. This paper focuses on the development of a simplified method for the quantitative risk assessment for natural gas pipelines and introduces parameters of fatal length and cumulative fatal length. The fatal length is defined as the integrated fatality along the pipeline associated with hypothetical accidents. The cumulative fatal length is defined as the section of pipeline in which an accident leads to N or more fatalities. These parameters can be estimated easily by using the information of pipeline geometry and population density of a Geographic Information Systems (GIS). To demonstrate the proposed method, individual and societal risks for a sample pipeline have been estimated from the historical data of European Gas Pipeline Incident Data Group and BG Transco. With currently acceptable criteria taken into account for individual risk, the minimum proximity of the pipeline to occupied buildings is approximately proportional to the square root of the operating pressure of the pipeline. The proposed method of quantitative risk assessment may be useful for risk management during the planning and building stages of a new pipeline, and modification of a buried pipeline

  18. Status of the natural and enriched uranium market: the basic economical factor for the development of the fuel cycle

    International Nuclear Information System (INIS)

    Nochev, T.

    1999-01-01

    Status of the Natural and Enriched Uranium Market - the Basic. Economical Factor for the Development of the Fuel Cycle An overview of the status of the natural and enriched uranium market has been performed and it offers a possibility to estimate the changes and tendencies, the knowledge of which is needed in negotiations about the fresh fuel. The simplified financial analysis presented here demonstrates the economical profitability of the storage of the spent fuel making now the allocations for the future reprocessing

  19. Exergic, economic and environmental impacts of natural gas and diesel in operation of combined cycle power plants

    International Nuclear Information System (INIS)

    Mohammadi Khoshkar Vandani, Amin; Joda, Fatemeh; Bozorgmehry Boozarjomehry, Ramin

    2016-01-01

    Highlights: • Investigating the effect of natural gas and diesel on the power plant performance. • Exergy, economic and environmental evaluation of a combined cycle power plant. • Using life cycle assessment (LCA) to perform the environmental evaluation. • Optimizing the power plant in terms of exergy and economic. • Better performance of natural gas with respect to diesel. - Abstract: Combined cycle power plants (CCPPs) play an important role in electricity production throughout the world. Their energy efficiency is relatively high and their production rates of greenhouse gases are considerably low. In a country like Iran with huge oil and gas resources, most CCPP’s use natural gas as primary fuel and diesel as secondary fuel. In this study, effect of using diesel instead of natural gas for a selected power plant will be investigated in terms of exergy, economic and environmental impacts. The environmental evaluation is performed using life cycle assessment (LCA). In the second step, the operation of the plant will be optimized using exergy and economic objective functions. The results show that the exergy efficiency of the plant with natural gas as fuel is equal to 43.11%, while this efficiency with diesel will be 42.03%. Furthermore, the annual cost of plant using diesel is twice as that of plant using natural gas. Finally, diesel utilization leads to more contaminants production. Thus, environmental effects of diesel are much higher than that of natural gas. The optimization results demonstrate that in case of natural gas, exergy efficiency and annual cost of the power plant improve 2.34% and 4.99%, respectively. While these improvements for diesel are 2.36% and 1.97%.

  20. The effect of endometrial scratch on natural-cycle cryopreserved embryo transfer outcomes: a randomized controlled study.

    Science.gov (United States)

    Mak, Jennifer Sze Man; Chung, Cathy Hoi Sze; Chung, Jacqueline Pui Wah; Kong, Grace Wing Shan; Saravelos, Sotirios H; Cheung, Lai Ping; Li, Tin-Chiu

    2017-07-01

    The benefit of endometrial scratch (ES) prior to embryo transfer is controversial. Systemic analysis has confirmed its potential benefit, especially in women with repeated IVF failures, yet most studies have focused on fresh embryo transfer, and its effect on vitrified-warmed embryo transfer (FET) cycles is yet to be explored. We hereby present our prospective, double-blind, randomized controlled study on the evaluation of the implantation and pregnancy rate after ES prior to natural-cycle FET. A total of 299 patients underwent natural-cycle FET and were randomized to receive ES (n = 115) or endocervical manipulation as control (n = 114) prior to FET cycle, and a total of 196 patients had embryo transfer (93 patients in each group). Our study showed no significant difference in the implantation and pregnancy rate, as well as the clinical and ongoing pregnancy or live birth rates between the two groups. It appears that ES does not have any beneficial effect on an unselected group of women undergoing FET in natural cycles. Further studies on its effect in women with recurrent implantation failure after IVF are warranted. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  1. Persistent infections after natural transmission of bovine viral diarrhoea virus from cattle to goats and among goats

    Science.gov (United States)

    2013-01-01

    Bovine viral diarrhoea virus (BVDV) is an economically important pathogen of cattle worldwide. Infection of a pregnant animal may lead to persistent infection of the foetus and birth of a persistently infected (PI) calf that sheds the virus throughout its life. However, BVD viruses are not strictly species specific. BVDV has been isolated from many domesticated and wild ruminants. This is of practical importance as virus reservoirs in non-bovine hosts may hamper BVDV control in cattle. A goat given as a social companion to a BVDV PI calf gave birth to a PI goat kid. In order to test if goat to goat infections were possible, seronegative pregnant goats were exposed to the PI goat. In parallel, seronegative pregnant goats were kept together with the PI calf. Only the goat to goat transmission resulted in the birth of a next generation of BVDV PI kids whereas all goats kept together with the PI calf aborted. To our knowledge, this is the first report which shows that a PI goat cannot only transmit BVD virus to other goats but that such transmission may indeed lead to the birth of a second generation of PI goats. Genetic analyses indicated that establishment in the new host species may be associated with step-wise adaptations in the viral genome. Thus, goats have the potential to be a reservoir for BVDV. However, the PI goats showed growth retardation and anaemia and their survival under natural conditions remains questionable. PMID:23675947

  2. Persistent infections after natural transmission of bovine viral diarrhoea virus from cattle to goats and among goats.

    Science.gov (United States)

    Bachofen, Claudia; Vogt, Hans-Rudolf; Stalder, Hanspeter; Mathys, Tanja; Zanoni, Reto; Hilbe, Monika; Schweizer, Matthias; Peterhans, Ernst

    2013-05-15

    Bovine viral diarrhoea virus (BVDV) is an economically important pathogen of cattle worldwide. Infection of a pregnant animal may lead to persistent infection of the foetus and birth of a persistently infected (PI) calf that sheds the virus throughout its life. However, BVD viruses are not strictly species specific. BVDV has been isolated from many domesticated and wild ruminants. This is of practical importance as virus reservoirs in non-bovine hosts may hamper BVDV control in cattle. A goat given as a social companion to a BVDV PI calf gave birth to a PI goat kid. In order to test if goat to goat infections were possible, seronegative pregnant goats were exposed to the PI goat. In parallel, seronegative pregnant goats were kept together with the PI calf. Only the goat to goat transmission resulted in the birth of a next generation of BVDV PI kids whereas all goats kept together with the PI calf aborted. To our knowledge, this is the first report which shows that a PI goat cannot only transmit BVD virus to other goats but that such transmission may indeed lead to the birth of a second generation of PI goats. Genetic analyses indicated that establishment in the new host species may be associated with step-wise adaptations in the viral genome. Thus, goats have the potential to be a reservoir for BVDV. However, the PI goats showed growth retardation and anaemia and their survival under natural conditions remains questionable.

  3. Comparative evaluation of hmopolesis and serum proteins from dogs with transmissible venereal tumor by natural ocorrence and induced by alogenic transplant

    International Nuclear Information System (INIS)

    Aptekmann, K.P.; Costa, M.T.; Fabeni, R. de C.; Santana, A.E.

    2005-01-01

    The objective of this study was to evaluate the haemopoiesis and total serum proteins of dogs with canine Transmissible Venereal Tumour (TVT) (naturally occurring or induced by allogenic transplant). Complete haemogram, bone marrow evaluation, total serum protein, albumin determination and electrophoretic fractionation of serum proteins were performed. Results revealed normocytic normochromic anaemia and thrombocytopenia in dogs with naturally occurring TVT

  4. Calculating the Optimum Angle of Filament-Wound Pipes in Natural Gas Transmission Pipelines Using Approximation Methods.

    Science.gov (United States)

    Reza Khoshravan Azar, Mohammad; Emami Satellou, Ali Akbar; Shishesaz, Mohammad; Salavati, Bahram

    2013-04-01

    Given the increasing use of composite materials in various industries, oil and gas industry also requires that more attention should be paid to these materials. Furthermore, due to variation in choice of materials, the materials needed for the mechanical strength, resistance in critical situations such as fire, costs and other priorities of the analysis carried out on them and the most optimal for achieving certain goals, are introduced. In this study, we will try to introduce appropriate choice for use in the natural gas transmission composite pipelines. Following a 4-layered filament-wound (FW) composite pipe will consider an offer our analyses under internal pressure. The analyses' results will be calculated for different combinations of angles 15 deg, 30 deg, 45 deg, 55 deg, 60 deg, 75 deg, and 80 deg. Finally, we will compare the calculated values and the optimal angle will be gained by using the Approximation methods. It is explained that this layering is as the symmetrical.

  5. Cumulative pregnancy rates after sequential treatment with modified natural cycle IVF followed by IVF with controlled ovarian stimulation

    NARCIS (Netherlands)

    Pelinck, M. J.; Knol, H. M.; Vogel, N. E. A.; Arts, E. G. J. M.; Simons, A. H. M.; Heineman, M. J.; Hoek, A.

    BACKGROUND: In modified natural cycle IVF (MNC-IVF), treatment is aimed at using the one follicle that spontaneously develops to dominance, using a GnRH-antagonist together with gonadotrophins in the late follicular phase only. The MNC-IVF is of interest because of its low-risk and patient-friendly

  6. Cumulative pregnancy rates after sequential treatment with modified natural cycle IVF followed by IVF with controlled ovarian stimulation

    NARCIS (Netherlands)

    Pelinck, M. J.; Knol, H. M.; Vogel, N. E. A.; Arts, E. G. J. M.; Simons, A. H. M.; Heineman, M. J.; Hoek, A.

    2008-01-01

    BACKGROUND: In modified natural cycle IVF (MNC-IVF), treatment is aimed at using the one follicle that spontaneously develops to dominance, using a GnRH-antagonist together with gonadotrophins in the late follicular phase only. The MNC-IVF is of interest because of its low-risk and patient-friendly

  7. Presence of bile acids in human follicular fluid and their relation with embryo development in modified natural cycle IVF

    NARCIS (Netherlands)

    Nagy, R. A.; van Montfoort, A. P. A.; Dikkers, A.; van Echten-Arends, J.; Homminga, I.; Land, J. A.; Hoek, A.; Tietge, U. J. F.

    STUDY QUESTION: Are bile acids (BA) and their respective subspecies present in human follicular fluid (FF) and do they relate to embryo quality in modified natural cycle IVF (MNC-IVF)? SUMMARY ANSWER: BAconcentrations are 2-fold higher in follicular fluid than in serum and ursodeoxycholic acid

  8. Design and optimisation of organic Rankine cycles for waste heat recovery in marine applications using the principles of natural selection

    DEFF Research Database (Denmark)

    Larsen, Ulrik; Pierobon, Leonardo; Haglind, Fredrik

    2013-01-01

    , boundary conditions, hazard levels and environmental concerns. A generally applicable methodology, based on the principles of natural selection, is presented and used to determine the optimum working fluid, boiler pressure and Rankine cycle process layout for scenarios related to marine engine heat...

  9. Cytokine production by natural killer lymphocytes in follicular and luteal phase of the ovarian cycle in humans

    NARCIS (Netherlands)

    Bouman, A.; Moes, H; Heineman, MJ; De Leij, LFMH; Faas, MM

    PROBLEM: The aim of this study was to test the hypothesis that, during luteal phase of the ovarian cycle, as compared with follicular phase, the cytokine productive capacity of peripheral natural killer (NK)-lymphocytes in humans is shifted towards a "Th2-type"-like response. METHOD OF STUDY:

  10. The exploitation of the physical exergy of liquid natural gas by closed power thermodynamic cycles. An overview

    International Nuclear Information System (INIS)

    Invernizzi, Costante M.; Iora, Paolo

    2016-01-01

    The world trade in LNG (liquefied natural gas) has tripled in the last 15 years and the forecasts are for its further rapid expansion. Although the cryogenic exergy of the LNG could be used in many industrial processes, it is recognized also as a source for power cycles. When using the low temperature capacity of LNG for power production, several thermodynamic cycles can be considered. This paper reports the state-of-the art of the most relevant solutions based on conventional and non-conventional thermodynamic closed cycles. Moreover, a novel metrics framework, suitable for a fairer comparison among the energy recovery performances of the different technologies is proposed. According to the defined indicators the compounds plants with gas turbine and closed Brayton cycles perform really better, with an almost full use of LNG available cold temperature and a fuel consumption with an efficiency better than that of the current combined cycles. The Rankine cycles with organic working fluids (pure fluids or non-azeotropic mixtures) using seawater or heat available at low temperature (for instance at 150 °C) also perform in a very satisfactory way. Real gas Brayton cycles and carbon dioxide condensation cycles work with very good thermal efficiency also at relatively low maximum temperatures (300 ÷ 600 °C) and could have peculiar applications. - Highlights: • A review of systems for the combined re-gasification of LNG and generation of power. • The considered systems are: closed Brayton cycles, condensation cycles, gas turbines. • Definition of new parameters for an energy assessment of the systems? performances. • A comparison among the various systems from the energy point of view.

  11. Can Children Break the Cycle of Disadvantage? Structure and Agency in the Transmission of Education across Generations

    Science.gov (United States)

    Burger, Kaspar; Walk, Marlene

    2016-01-01

    Research has shown that parents tend to pass educational advantage or disadvantage on to their children. However, little is known about the extent to which the intergenerational transmission of education involves children's agency. In this study we drew from two traditions in sociological and social psychological theorizing--the theory of cultural…

  12. Phosphorus cycling in natural and low input soil/plant systems: the role of soil microorganisms

    Science.gov (United States)

    Tamburini, F.; Bünemann, E. K.; Oberson, A.; Bernasconi, S. M.; Frossard, E.

    2011-12-01

    was faster in the P-free treatment. Laboratory incubation also showed a more rapid P uptake by microbial biomass in the NK than in the NPK treatment (37% and 6% of added 33P recovered in microbial P after 100 minutes in NK and NPK, respectively). The seasonal microbial P flux in both treatments was 1.5-4 times larger than the annual plant P uptake. In field studies carried out on highly weathered low P soils in Colombia, the comparison between grass-legume and grass-only pastures showed that the presence of legumes had an impact on the overall biological activity. In fact, microbial biomass and phosphatase activity were significantly larger in grass-legume pastures than in the legume-free experiments. Larger release of Pi from the organic P pool improved P availability to plants and pointed at a modified C:N:P stoichiometry along pathways of the nutrient cycle in the soil/plant system. All these data are evidence of a highly dynamic microbial P pool, which controls Pi concentration and, hence, availability for plants in natural and low input agricultural ecosystems.

  13. Two distinct variants of simian foamy virus in naturally infected mandrills (Mandrillus sphinx and cross-species transmission to humans

    Directory of Open Access Journals (Sweden)

    Marx Preston

    2010-12-01

    Full Text Available Abstract Background Each of the pathogenic human retroviruses (HIV-1/2 and HTLV-1 has a nonhuman primate counterpart, and the presence of these retroviruses in humans results from interspecies transmission. The passage of another simian retrovirus, simian foamy virus (SFV, from apes or monkeys to humans has been reported. Mandrillus sphinx, a monkey species living in central Africa, is naturally infected with SFV. We evaluated the natural history of the virus in a free-ranging colony of mandrills and investigated possible transmission of mandrill SFV to humans. Results We studied 84 semi-free-ranging captive mandrills at the Primate Centre of the Centre International de Recherches Médicales de Franceville (Gabon and 15 wild mandrills caught in various areas of the country. The presence of SFV was also evaluated in 20 people who worked closely with mandrills and other nonhuman primates. SFV infection was determined by specific serological (Western blot and molecular (nested PCR of the integrase region in the polymerase gene assays. Seropositivity for SFV was found in 70/84 (83% captive and 9/15 (60% wild-caught mandrills and in 2/20 (10% humans. The 425-bp SFV integrase fragment was detected in peripheral blood DNA from 53 captive and 8 wild-caught mandrills and in two personnel. Sequence and phylogenetic studies demonstrated the presence of two distinct strains of mandrill SFV, one clade including SFVs from mandrills living in the northern part of Gabon and the second consisting of SFV from animals living in the south. One man who had been bitten 10 years earlier by a mandrill and another bitten 22 years earlier by a macaque were found to be SFV infected, both at the Primate Centre. The second man had a sequence close to SFVmac sequences. Comparative sequence analysis of the virus from the first man and from the mandrill showed nearly identical sequences, indicating genetic stability of SFV over time. Conclusion Our results show a high

  14. Two distinct variants of simian foamy virus in naturally infected mandrills (Mandrillus sphinx) and cross-species transmission to humans.

    Science.gov (United States)

    Mouinga-Ondémé, Augustin; Betsem, Edouard; Caron, Mélanie; Makuwa, Maria; Sallé, Bettina; Renault, Noemie; Saib, Ali; Telfer, Paul; Marx, Preston; Gessain, Antoine; Kazanji, Mirdad

    2010-12-14

    Each of the pathogenic human retroviruses (HIV-1/2 and HTLV-1) has a nonhuman primate counterpart, and the presence of these retroviruses in humans results from interspecies transmission. The passage of another simian retrovirus, simian foamy virus (SFV), from apes or monkeys to humans has been reported. Mandrillus sphinx, a monkey species living in central Africa, is naturally infected with SFV. We evaluated the natural history of the virus in a free-ranging colony of mandrills and investigated possible transmission of mandrill SFV to humans. We studied 84 semi-free-ranging captive mandrills at the Primate Centre of the Centre International de Recherches Médicales de Franceville (Gabon) and 15 wild mandrills caught in various areas of the country. The presence of SFV was also evaluated in 20 people who worked closely with mandrills and other nonhuman primates. SFV infection was determined by specific serological (Western blot) and molecular (nested PCR of the integrase region in the polymerase gene) assays. Seropositivity for SFV was found in 70/84 (83%) captive and 9/15 (60%) wild-caught mandrills and in 2/20 (10%) humans. The 425-bp SFV integrase fragment was detected in peripheral blood DNA from 53 captive and 8 wild-caught mandrills and in two personnel. Sequence and phylogenetic studies demonstrated the presence of two distinct strains of mandrill SFV, one clade including SFVs from mandrills living in the northern part of Gabon and the second consisting of SFV from animals living in the south. One man who had been bitten 10 years earlier by a mandrill and another bitten 22 years earlier by a macaque were found to be SFV infected, both at the Primate Centre. The second man had a sequence close to SFVmac sequences. Comparative sequence analysis of the virus from the first man and from the mandrill showed nearly identical sequences, indicating genetic stability of SFV over time. Our results show a high prevalence of SFV infection in a semi-free-ranging colony

  15. Routes of Hendra Virus Excretion in Naturally-Infected Flying-Foxes: Implications for Viral Transmission and Spillover Risk.

    Directory of Open Access Journals (Sweden)

    Daniel Edson

    Full Text Available Pteropid bats or flying-foxes (Chiroptera: Pteropodidae are the natural host of Hendra virus (HeV which sporadically causes fatal disease in horses and humans in eastern Australia. While there is strong evidence that urine is an important infectious medium that likely drives bat to bat transmission and bat to horse transmission, there is uncertainty about the relative importance of alternative routes of excretion such as nasal and oral secretions, and faeces. Identifying the potential routes of HeV excretion in flying-foxes is important to effectively mitigate equine exposure risk at the bat-horse interface, and in determining transmission rates in host-pathogen models. The aim of this study was to identify the major routes of HeV excretion in naturally infected flying-foxes, and secondarily, to identify between-species variation in excretion prevalence. A total of 2840 flying-foxes from three of the four Australian mainland species (Pteropus alecto, P. poliocephalus and P. scapulatus were captured and sampled at multiple roost locations in the eastern states of Queensland and New South Wales between 2012 and 2014. A range of biological samples (urine and serum, and urogenital, nasal, oral and rectal swabs were collected from anaesthetized bats, and tested for HeV RNA using a qRT-PCR assay targeting the M gene. Forty-two P. alecto (n = 1410 had HeV RNA detected in at least one sample, and yielded a total of 78 positive samples, at an overall detection rate of 1.76% across all samples tested in this species (78/4436. The rate of detection, and the amount of viral RNA, was highest in urine samples (>serum, packed haemocytes >faecal >nasal >oral, identifying urine as the most plausible source of infection for flying-foxes and for horses. Detection in a urine sample was more efficient than detection in urogenital swabs, identifying the former as the preferred diagnostic sample. The detection of HeV RNA in serum is consistent with haematogenous

  16. The Antarctic krill Euphausia superba shows diurnal cycles of transcription under natural conditions.

    Directory of Open Access Journals (Sweden)

    Cristiano De Pittà

    Full Text Available BACKGROUND: Polar environments are characterized by extreme seasonal changes in day length, light intensity and spectrum, the extent of sea ice during the winter, and food availability. A key species of the Southern Ocean ecosystem, the Antarctic krill (Euphausia superba has evolved rhythmic physiological and behavioral mechanisms to adapt to daily and seasonal changes. The molecular organization of the clockwork underlying these biological rhythms is, nevertheless, still only partially understood. METHODOLOGY/PRINCIPAL FINDINGS: The genome sequence of the Antarctic krill is not yet available. A normalized cDNA library was produced and pyrosequenced in the attempt to identify large numbers of transcripts. All available E. superba sequences were then assembled to create the most complete existing oligonucleotide microarray platform with a total of 32,217 probes. Gene expression signatures of specimens collected in the Ross Sea at five different time points over a 24-hour cycle were defined, and 1,308 genes differentially expressed were identified. Of the corresponding transcripts, 609 showed a significant sinusoidal expression pattern; about 40% of these exibithed a 24-hour periodicity while the other 60% was characterized by a shorter (about 12-hour rhythm. We assigned the differentially expressed genes to functional categories and noticed that those concerning translation, proteolysis, energy and metabolic process, redox regulation, visual transduction and stress response, which are most likely related to daily environmental changes, were significantly enriched. Two transcripts of peroxiredoxin, thought to represent the ancestral timekeeping system that evolved about 2.5 billion years ago, were also identified as were two isoforms of the EsRh1 opsin and two novel arrestin1 sequences involved in the visual transduction cascade. CONCLUSIONS: Our work represents the first characterization of the krill diurnal transcriptome under natural conditions

  17. Linking AS, SE, V, and MN Behavior to Natural Biostimulated Uranium Cycling

    Energy Technology Data Exchange (ETDEWEB)

    Keimowitz, Alison [Vassar College, Poughkeepsie, NY (United States); Ranville, James [Colorado School of Mines, Golden, CO (United States); Mailloux, Brian [Barnard College, New York, NY (United States); Figueroa, Linda [Colorado School of Mines, Golden, CO (United States)

    2016-03-16

    The project “Linking As, Se, V, and Mn behavior to Natural and Biostimulated Uranium Cycling” successfully investigated Arsenic cycling the Rifle Colorado IFRC. This project trained undergraduate and graduate students at the Colorado School of Mines, Vassar College, and Barnard College. This resulted in both undergraduate theses and a PhD thesis and multiple publications. The science was highly successful and we were able to test the main hypotheses. We have shown that (H1) under reducing conditions that promote uranium immobilization arsenic is readily mobilized, that (H2) thioarsenic species are abundant during this mobilization, and (H3) we have examined arsenic mobilization for site sediment. At the Rifle IFRC Acetate was added during experiments to immobilize Uranium. These experiments successfully immobilized uranium but unfortunately would mobilize arsenic. We developed robust sampling and analysis methods for thioarsenic species. We showed that the mobilization occurred under sulfate reducing conditions and the majority of the arsenic was in the form of thioarsenic species. Previous studies had predicted the presence of thioarsenic species but this study used robust field and laboratory methods to quantitatively determine the presence of thioarsenic species. During stimulation in wells with high arsenic the primary species were trithioarsenate and dithioarsenate. In wells with low levels of arsenic release thioarsenates were absent or minor components. Fortunately after the injection of acetate ended the aquifer would become less reducing and the arsenic concentrations would decrease to pre-injection levels. In aquifers where organic carbon is being added as a remedial method or as a contaminant the transient mobility of arsenic during sulfidogenesis should be considered especially in sulfate rich aquifers as this could impact downgradient water quality.

  18. Inter-relações entre os ciclos de transmissão do Trypanosoma cruzi no município de Bambuí, Minas Gerais, Brasil Relationships between Trypanosoma cruzi transmission cycles in the county of Bambuí, Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Alexandre José Fernandes

    1994-12-01

    ciclos de transmissão do T. cruzi Z2 no peridomicílio e domicílio, propiciando de forma gradual a reinfestação do município caso a Vigilância Epidemiológica seja interrompida.This study examines recent relationships between domestic and sylvatic transmission cycles of T.cruzi in the county of Bambuí, MG, Brazil. In the late l930s, Panstrongylus megistus was found in 75% of houses. Subsequently, Triatoma infestans became the predominant species, found in 20% of urban households and in more than 60% of periurban homes. With intense insecticide control campaigns between l956 and l969, T. infestans was eradicated from the county, transmission of Chagas' disease to man was interrupted, and P. mesgistus appeared in rural residences. Samples of T. cruzi isolated by xenodiagnosis and hemoculture from 43 opossums (Didelphis albiventris captured in both peridomiciliary and sylvatic areas were characterized by isoenzyme analysis and - regardless of isolation method - were found to present the Z1 zymodeme profile. Through the "Chagas' Disease Epidemiological Surveillance Program", from August l986 to December l988, 154 specimens of P. megistus were captured by the local population in both peridomiciliary and intradomiciliary environments, of which 9.8% were infected with T. cruzi. In isoenzyme analyses of l3 T. cruzi strains isolated from these triatomines, six were found to be of the Z1 zymodeme (sylvatic transmission cycles and seven were found to be of the Z2 zymodeme (domestic transmission cycle. The capture of P. megistus specimens in intradomiciliary environments that were naturally infected with parasites of both cycle types indicates an overlap of transmission cycles of Chagas' disease in the county of Bambuí. Further evidence for the interrelationship of the two cycles was provided by the isolation of T. cruzi of the Z2 zymodeme from a cat and the participation of the dog as a reservoir of Z1 T. cruzi. The presence of P. megistus in the peridomiciliary environment

  19. Trypanosoma cruzi I genotypes in different geographic regions and transmission cycles based on a microsatellite motif of the intergenic spacer of spliced leader genes✯

    Science.gov (United States)

    Cura, Carolina I.; Mejía-Jaramillo, Ana M.; Duffy, Tomás; Burgos, Juan M.; Rodriguero, Marcela; Cardinal, Marta V.; Kjos, Sonia; Gurgel-Gonçalves, Rodrigo; Blanchet, Denis; De Pablos, Luis M.; Tomasini, Nicolás; Silva, Alex Da; Russomando, Graciela; Cuba Cuba, Cesar A.; Aznar, Christine; Abate, Teresa; Levin, Mariano J.; Osuna, Antonio; Gürtler, Ricardo E.; Diosque, Patricio; Solari, Aldo; Triana-Chávez, Omar; Schijman, Alejandro G.

    2011-01-01

    The intergenic region of spliced-leader (SL-IR) genes from 105 Trypanosoma cruzi I (Tc I) infected biological samples, culture isolates and stocks from 11 endemic countries, from Argentina to the USA were characterised, allowing identification of 76 genotypes with 54 polymorphic sites from 123 aligned sequences. On the basis of the microsatellite motif proposed by Herrera et al. (2007) to define four haplotypes in Colombia, we could classify these genotypes into four distinct Tc I SL-IR groups, three corresponding to the former haplotypes Ia (11 genotypes), Ib (11 genotypes) and Id (35 genotypes); and one novel group, Ie (19 genotypes). Genotypes harboring the Tc Ic motif were not detected in our study. Tc Ia was associated with domestic cycles in southern and northern South America and sylvatic cycles in Central and North America. Tc Ib was found in all transmission cycles from Colombia. Tc Id was identified in all transmission cycles from Argentina and Colombia, including Chagas cardiomyopathy patients, sylvatic Brazilian samples and human cases from French Guiana, Panama and Venezuela. Tc Ie gathered five samples from domestic Triatoma infestans from northern Argentina, nine samples from wild Mepraia spinolai and Mepraia gajardoi and two chagasic patients from Chile and one from a Bolivian patient with chagasic reactivation. Mixed infections by Tc Ia + Tc Id, Tc Ia + Tc Ie and Tc Id + Tc Ie were detected in vector faeces and isolates from human and vector samples. In addition, Tc Ia and Tc Id were identified in different tissues from a heart transplanted Chagas cardiomyopathy patient with reactivation, denoting histotropism. Trypanosoma cruzi I SL-IR genotypes from parasites infecting Triatoma gerstaeckeri and Didelphis virginiana from USA, T. infestans from Paraguay, Rhodnius nasutus and Rhodnius neglectus from Brazil and M. spinolai and M. gajardoi from Chile are to our knowledge described for the first time. PMID:20670628

  20. Can children break the cycle of disadvantage? Structure and agency in the transmission of education across generations

    OpenAIRE

    Burger, Kaspar; Walk, Marlene

    2016-01-01

    Research has shown that parents tend to pass educational advantage or disadvantage on to their children. However, little is known about the extent to which the intergenerational transmission of education involves children’s agency. In this study we drew from two traditions in sociological and social psychological theorizing – the theory of cultural and social reproduction and the theory of human agency – to examine whether agency influences children’s educational performance, and if so, wheth...

  1. Crystal Structure of Borrelia turicatae protein, BTA121, a differentially regulated  gene in the tick-mammalian transmission cycle of relapsing fever spirochetes

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Zhipu; Kelleher, Alan J.; Darwiche, Rabih; Hudspeth, Elissa M.; Shittu, Oluwatosin K.; Krishnavajhala, Aparna; Schneiter, Roger; Lopez, Job E.; Asojo, Oluwatoyin A. (Baylor); (Fribourg); (NCI)

    2017-11-10

    Tick-borne relapsing fever (RF) borreliosis is a neglected disease that is often misdiagnosed. RF species circulating in the United States include Borrelia turicatae, which is transmitted by argasid ticks. Environmental adaptation by RF Borrelia is poorly understood, however our previous studies indicated differential regulation of B. turicatae genes localized on the 150 kb linear megaplasmid during the tick-mammalian transmission cycle, including bta121. This gene is up-regulated by B. turicatae in the tick versus the mammal, and the encoded protein (BTA121) is predicted to be surface localized. The structure of BTA121 was solved by single-wavelength anomalous dispersion (SAD) using selenomethionine-derivative protein. The topology of BTA121 is unique with four helical domains organized into two helical bundles. Due to the sequence similarity of several genes on the megaplasmid, BTA121 can serve as a model for their tertiary structures. BTA121 has large interconnected tunnels and cavities that can accommodate ligands, notably long parallel helices, which have a large hydrophobic central pocket. Preliminary in-vitro studies suggest that BTA121 binds lipids, notably palmitate with a similar order of binding affinity as tablysin-15, a known palmitate-binding protein. The reported data will guide mechanistic studies to determine the role of BTA121 in the tick-mammalian transmission cycle of B. turicatae.

  2. An analysis of land use planning and equity issues surrounding hazardous liquid and natural gas transmission pipelines in North Carolina

    Science.gov (United States)

    Osland, Anna Christine

    Hazardous liquid and natural gas transmission pipelines have received limited attention by planning scholars even though local development decisions can have broad consequences if a rupture occurs. In this dissertation, I evaluated the implications of land-use planning for reducing risk to transmission pipeline hazards in North Carolina via three investigations. First, using a survey of planning directors in jurisdictions with transmission pipeline hazards, I investigated the land use planning tools used to mitigate pipeline hazards and the factors associated with tool adoption. Planning scholars have documented the difficulty of inducing planning in hazardous areas, yet there remain gaps in knowledge about the factors associated with tool adoption. Despite the risks associated with pipeline ruptures, I found most localities use few mitigation tools, and the adoption of regulatory and informational tools appear to be influenced by divergent factors. Whereas risk perception, commitment, capacity, and community context were associated with total tool and information tool use, only risk perception and capacity factors were associated with regulatory tool use. Second, using interviews of emergency managers and planning directors, I examined the role of agency collaboration for building mitigation capacity. Scholars have highlighted the potential of technical collaboration, yet less research has investigated how inter-agency collaboration shapes mitigation capacity. I identify three categories of technical collaboration, discuss how collaborative spillovers can occur from one planning area to another, and challenge the notion that all technical collaborations result in equal mitigation outcomes. Third, I evaluated characteristics of the population near pipelines to address equity concerns. Surprisingly, I did not find broad support for differences in exposure of vulnerable populations. Nonetheless, my analyses uncovered statistically significant clusters of vulnerable

  3. Closing the natural cycles - using biowaste compost in organic farming in Vienna

    Science.gov (United States)

    Erhart, Eva; Rogalski, Wojciech; Maurer, Ludwig; Hartl, Wilfried

    2014-05-01

    One of the basic principles of organic farming - that organic management should fit the cycles and ecological balances in nature - is put into practice in Vienna on a large scale. In Vienna, compost produced from separately collected biowaste and greenwaste is used on more than 1000 ha of organic farmland. These municipally owned farms are managed organically, but are stockless, like the vast majority of farms in the region. The apparent need for a substitute for animal manure triggered the development of an innovative biowaste management. Together with the Municipal Department 48 responsible for waste management, which was keen for the reduction of residual waste, the Municipal Department 49 - Forestry Office and Urban Agriculture and Bio Forschung Austria developed Vienna's biowaste management model. Organic household wastes and greenwastes are source-separated by the urban population and collected in a closely monitored system to ensure high compost quality. A composting plant was constructed which today produces a total of 43000 t compost per year in a monitored open windrow process. The quality of the compost produced conforms to the EU regulation 834/2007. A large part of the compost is used as organic fertilizer on the organic farmland in Vienna, and the remainder is used in arable farming and in viticulture in the region around Vienna and for substrate production. Vienna`s biowaste management-model is operating successfully since the 1980s and has gained international recognition in form of the Best Practice-Award of the United Nations Development Programme. In order to assess the effects of biowaste compost fertilization on crop yield and on the environment, a field experiment was set up near Vienna in 1992, which is now one of the longest standing compost experiments in Europe. The results showed, that the yields increased for 7 - 10 % with compost fertilization compared to the unfertilized control and the nitrogen recovery by crops was between 4 and 6

  4. Total fuel-cycle analysis of heavy-duty vehicles using biofuels and natural gas-based alternative fuels.

    Science.gov (United States)

    Meyer, Patrick E; Green, Erin H; Corbett, James J; Mas, Carl; Winebrake, James J

    2011-03-01

    Heavy-duty vehicles (HDVs) present a growing energy and environmental concern worldwide. These vehicles rely almost entirely on diesel fuel for propulsion and create problems associated with local pollution, climate change, and energy security. Given these problems and the expected global expansion of HDVs in transportation sectors, industry and governments are pursuing biofuels and natural gas as potential alternative fuels for HDVs. Using recent lifecycle datasets, this paper evaluates the energy and emissions impacts of these fuels in the HDV sector by conducting a total fuel-cycle (TFC) analysis for Class 8 HDVs for six fuel pathways: (1) petroleum to ultra low sulfur diesel; (2) petroleum and soyoil to biodiesel (methyl soy ester); (3) petroleum, ethanol, and oxygenate to e-diesel; (4) petroleum and natural gas to Fischer-Tropsch diesel; (5) natural gas to compressed natural gas; and (6) natural gas to liquefied natural gas. TFC emissions are evaluated for three greenhouse gases (GHGs) (carbon dioxide, nitrous oxide, and methane) and five other pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, particulate matter, and sulfur oxides), along with estimates of total energy and petroleum consumption associated with each of the six fuel pathways. Results show definite advantages with biodiesel and compressed natural gas for most pollutants, negligible benefits for e-diesel, and increased GHG emissions for liquefied natural gas and Fischer-Tropsch diesel (from natural gas).

  5. From concept(ion) to life after death/the grave: The 'natural' history and life cycle(s) of novel psychoactive substances (NPS).

    Science.gov (United States)

    Corkery, John Martin; Orsolini, Laura; Papanti, Duccio; Schifano, Fabrizio

    2017-05-01

    A range of information needs should be met in order to better understand and predict the longevity/existence of novel psychoactive substances (NPS). This conceptual paper argues that one way of assessing how long a molecule may be around is to document how the life cycles or natural histories of 'traditional' drugs and NPS evolve. The earliest indication of the possible appearance of a new substance might be evidenced on the DeepWeb. However, this means they are less visible, in line with the clandestine nature of drug use and supply. Therefore, monitoring discussion groups/fora needs the development of new methods compared to those used in the Surface Net. Issues needing consideration in establishing NPS life cycles are outlined here, together with the probable outcomes that could result. The approach advocated means that it should be easier to identify which NPS are likely to come up or are emerging in real time, and, therefore, pre-empt/prevent their supply. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Comparison of life cycle greenhouse gases from natural gas pathways for medium and heavy-duty vehicles.

    Science.gov (United States)

    Tong, Fan; Jaramillo, Paulina; Azevedo, Inês M L

    2015-06-16

    The low-cost and abundant supply of shale gas in the United States has increased the interest in using natural gas for transportation. We compare the life cycle greenhouse gas (GHG) emissions from different natural gas pathways for medium and heavy-duty vehicles (MHDVs). For Class 8 tractor-trailers and refuse trucks, none of the natural gas pathways provide emissions reductions per unit of freight-distance moved compared to diesel trucks. When compared to the petroleum-based fuels currently used in these vehicles, CNG and centrally produced LNG increase emissions by 0-3% and 2-13%, respectively, for Class 8 trucks. Battery electric vehicles (BEVs) powered with natural gas-produced electricity are the only fuel-technology combination that achieves emission reductions for Class 8 transit buses (31% reduction compared to the petroleum-fueled vehicles). For non-Class 8 trucks (pick-up trucks, parcel delivery trucks, and box trucks), BEVs reduce emissions significantly (31-40%) compared to their diesel or gasoline counterparts. CNG and propane achieve relatively smaller emissions reductions (0-6% and 19%, respectively, compared to the petroleum-based fuels), while other natural gas pathways increase emissions for non-Class 8 MHDVs. While using natural gas to fuel electric vehicles could achieve large emission reductions for medium-duty trucks, the results suggest there are no great opportunities to achieve large emission reductions for Class 8 trucks through natural gas pathways with current technologies. There are strategies to reduce the carbon footprint of using natural gas for MHDVs, ranging from increasing vehicle fuel efficiency, reducing life cycle methane leakage rate, to achieving the same payloads and cargo volumes as conventional diesel trucks.

  7. Signatures of natural selection between life cycle stages separated by metamorphosis in European eel

    DEFF Research Database (Denmark)

    Pujolar, J.M.; Jacobsen, M.W.; Bekkevold, Dorte

    2015-01-01

    Species showing complex life cycles provide excellent opportunities to study the genetic associations between life cycle stages, as selective pressures may differ before and after metamorphosis. The European eel presents a complex life cycle with two metamorphoses, a first metamorphosis from larvae...... into glass eels (juvenile stage) and a second metamorphosis into silver eels (adult stage). We tested the hypothesis that different genes and gene pathways will be under selection at different life stages when comparing the genetic associations between glass eels and silver eels. Results: We used two sets...... of markers to test for selection: first, we genotyped individuals using a panel of 80 coding-gene single nucleotide polymorphisms (SNPs) developed in American eel; second, we investigated selection at the genome level using a total of 153,423 RAD-sequencing generated SNPs widely distributed across the genome...

  8. Low temperature heat from natural gas. Life cycle analysis for efficient systems

    International Nuclear Information System (INIS)

    Zogg, M.

    2000-01-01

    A life cycle analysis drawn up on behalf of the Swiss Federal Office of Energy shows that the combined cycle power plant + heat pump (GuD-WP) combination produces less greenhouse effect and makes only about half the contribution to summer smog formation as the operation of heat pumps with the power mix habitually used in Western Europe today. In the co-generation unit + heat pump (BHKW-WP) combination, the environmental impact shows the same values as in current West European power generation

  9. Electrochemical Noise Sensors for Detection of Localized and General Corrosion of Natural Gas Transmission Pipelines. Final Report for the Period July 2001-October 2002

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, Sophie J.; Covino, Jr., Bernard S.; Russell, James H.; Holcomb, Gordon R.; Cramer, Stephen D.; Ziomek-Moroz, Margaret

    2002-12-01

    The U.S. Department of Energy, National Energy Technology Laboratory funded a Natural Gas Infrastructure Reliability program directed at increasing and enhancing research and development activities in topics such as remote leak detection, pipe inspection, and repair technologies and materials. The Albany Research Center (ARC), U.S. Department of Energy was funded to study the use of electrochemical noise sensors for detection of localized and general corrosion of natural gas transmission pipelines. As part of this, ARC entered into a collaborative effort with the corrosion sensor industry to demonstrate the capabilities of commercially available remote corrosion sensors for use with the Nation's Gas Transmission Pipeline Infrastructure needs. The goal of the research was to develop an emerging corrosion sensor technology into a monitor for the type and degree of corrosion occurring at key locations in gas transmission pipelines.

  10. Performance analysis of different organic Rankine cycle configurations on board liquefied natural gas-fuelled vessels

    DEFF Research Database (Denmark)

    Baldasso, Enrico; Andreasen, Jesper Graa; Meroni, Andrea

    2017-01-01

    Gas-fuelled shipping is expected to increase significantly in the coming years. Similarly, much effort is devoted to the study of waste heat recovery systems to be implemented on board ships. In this context, the organic Rankine cycle (ORC) technology is considered one of the most promising...

  11. Cross-border trading and transmission networks: a model for competition in natural gas and electricity grids

    International Nuclear Information System (INIS)

    Hogan, W.W.

    1992-01-01

    Cross border energy trading, for which transmission networks are a vital policy, is expanding. Within an environment of competition and open access, reform of transmission pricing, access and investment is needed. A theoretical framework for such reform is outlined. The design objectives advocated are to maintain a reliable service; to provide economic efficiency; to allow for long-term transmission contracts; to arrange compensation through a settlements system; to allow decomposition by region and company and to preserve administrative feasibility. A ''contract network'' model for transmission rights in a network is discussed. (UK)

  12. Signatures of natural selection between life cycle stages separated by metamorphosis in European eel.

    Science.gov (United States)

    Pujolar, J M; Jacobsen, M W; Bekkevold, D; Lobón-Cervià, J; Jónsson, B; Bernatchez, L; Hansen, M M

    2015-08-13

    Species showing complex life cycles provide excellent opportunities to study the genetic associations between life cycle stages, as selective pressures may differ before and after metamorphosis. The European eel presents a complex life cycle with two metamorphoses, a first metamorphosis from larvae into glass eels (juvenile stage) and a second metamorphosis into silver eels (adult stage). We tested the hypothesis that different genes and gene pathways will be under selection at different life stages when comparing the genetic associations between glass eels and silver eels. We used two sets of markers to test for selection: first, we genotyped individuals using a panel of 80 coding-gene single nucleotide polymorphisms (SNPs) developed in American eel; second, we investigated selection at the genome level using a total of 153,423 RAD-sequencing generated SNPs widely distributed across the genome. Using the RAD approach, outlier tests identified a total of 2413 (1.57%) potentially selected SNPs. Functional annotation analysis identified signal transduction pathways as the most over-represented group of genes, including MAPK/Erk signalling, calcium signalling and GnRH (gonadotropin-releasing hormone) signalling. Many of the over-represented pathways were related to growth, while others could result from the different conditions that eels inhabit during their life cycle. The observation of different genes and gene pathways under selection when comparing glass eels vs. silver eels supports the adaptive decoupling hypothesis for the benefits of metamorphosis. Partitioning the life cycle into discrete morphological phases may be overall beneficial since it allows the different life stages to respond independently to their unique selection pressures. This might translate into a more effective use of food and niche resources and/or performance of phase-specific tasks (e.g. feeding in the case of glass eels, migrating and reproducing in the case of silver eels).

  13. A Natural Light/Dark Cycle Regulation of Carbon-Nitrogen Metabolism and Gene Expression in Rice Shoots.

    Science.gov (United States)

    Li, Haixing; Liang, Zhijun; Ding, Guangda; Shi, Lei; Xu, Fangsen; Cai, Hongmei

    2016-01-01

    Light and temperature are two particularly important environmental cues for plant survival. Carbon and nitrogen are two essential macronutrients required for plant growth and development, and cellular carbon and nitrogen metabolism must be tightly coordinated. In order to understand how the natural light/dark cycle regulates carbon and nitrogen metabolism in rice plants, we analyzed the photosynthesis, key carbon-nitrogen metabolites, and enzyme activities, and differentially expressed genes and miRNAs involved in the carbon and nitrogen metabolic pathway in rice shoots at the following times: 2:00, 6:00, 10:00, 14:00, 18:00, and 22:00. Our results indicated that more CO2 was fixed into carbohydrates by a high net photosynthetic rate, respiratory rate, and stomatal conductance in the daytime. Although high levels of the nitrate reductase activity, free ammonium and carbohydrates were exhibited in the daytime, the protein synthesis was not significantly facilitated by the light and temperature. In mRNA sequencing, the carbon and nitrogen metabolism-related differentially expressed genes were obtained, which could be divided into eight groups: photosynthesis, TCA cycle, sugar transport, sugar metabolism, nitrogen transport, nitrogen reduction, amino acid metabolism, and nitrogen regulation. Additionally, a total of 78,306 alternative splicing events have been identified, which primarily belong to alternative 5' donor sites, alternative 3' acceptor sites, intron retention, and exon skipping. In sRNA sequencing, four carbon and nitrogen metabolism-related miRNAs (osa-miR1440b, osa-miR2876-5p, osa-miR1877 and osa-miR5799) were determined to be regulated by natural light/dark cycle. The expression level analysis showed that the four carbon and nitrogen metabolism-related miRNAs negatively regulated their target genes. These results may provide a good strategy to study how natural light/dark cycle regulates carbon and nitrogen metabolism to ensure plant growth and

  14. Causal pathways linking environmental change with health behaviour change: Natural experimental study of new transport infrastructure and cycling to work.

    Science.gov (United States)

    Prins, R G; Panter, J; Heinen, E; Griffin, S J; Ogilvie, D B

    2016-06-01

    Mechanisms linking changes to the environment with changes in physical activity are poorly understood. Insights into mechanisms of interventions can help strengthen causal attribution and improve understanding of divergent response patterns. We examined the causal pathways linking exposure to new transport infrastructure with changes in cycling to work. We used baseline (2009) and follow-up (2012) data (N=469) from the Commuting and Health in Cambridge natural experimental study (Cambridge, UK). Exposure to new infrastructure in the form of the Cambridgeshire Guided Busway was defined using residential proximity. Mediators studied were changes in perceptions of the route to work, theory of planned behaviour constructs and self-reported use of the new infrastructure. Outcomes were modelled as an increase, decrease or no change in weekly cycle commuting time. We used regression analyses to identify combinations of mediators forming potential pathways between exposure and outcome. We then tested these pathways in a path model and stratified analyses by baseline level of active commuting. We identified changes in perceptions of the route to work, and use of the cycle path, as potential mediators. Of these potential mediators, only use of the path significantly explained (85%) the effect of the infrastructure in increasing cycling. Path use also explained a decrease in cycling among more active commuters. The findings strengthen the causal argument that changing the environment led to changes in health-related behaviour via use of the new infrastructure, but also show how some commuters may have spent less time cycling as a result. Copyright © 2016. Published by Elsevier Inc.

  15. Environmental impact efficiency of natural gas combined cycle power plants: A combined life cycle assessment and dynamic data envelopment analysis approach.

    Science.gov (United States)

    Martín-Gamboa, Mario; Iribarren, Diego; Dufour, Javier

    2018-02-15

    The energy sector is still dominated by the use of fossil resources. In particular, natural gas represents the third most consumed resource, being a significant source of electricity in many countries. Since electricity production in natural gas combined cycle (NGCC) plants provides some benefits with respect to other non-renewable technologies, it is often seen as a transitional solution towards a future low‑carbon power generation system. However, given the environmental profile and operational variability of NGCC power plants, their eco-efficiency assessment is required. In this respect, this article uses a novel combined Life Cycle Assessment (LCA) and dynamic Data Envelopment Analysis (DEA) approach in order to estimate -over the period 2010-2015- the environmental impact efficiencies of 20 NGCC power plants located in Spain. A three-step LCA+DEA method is applied, which involves data acquisition, calculation of environmental impacts through LCA, and the novel estimation of environmental impact efficiency (overall- and term-efficiency scores) through dynamic DEA. Although only 1 out of 20 NGCC power plants is found to be environmentally efficient, all plants show a relatively good environmental performance with overall eco-efficiency scores above 60%. Regarding individual periods, 2011 was -on average- the year with the highest environmental impact efficiency (95%), accounting for 5 efficient NGCC plants. In this respect, a link between high number of operating hours and high environmental impact efficiency is observed. Finally, preliminary environmental benchmarks are presented as an additional outcome in order to further support decision-makers in the path towards eco-efficiency in NGCC power plants. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Modified natural cycle versus controlled ovarian hyperstimulation IVF: a cost-effectiveness evaluation of three simulated treatment scenarios.

    Science.gov (United States)

    Groen, Henk; Tonch, Nino; Simons, Arnold H M; van der Veen, Fulco; Hoek, Annemieke; Land, Jolande A

    2013-12-01

    Can modified natural cycle IVF or ICSI (MNC) be a cost-effective alternative for controlled ovarian hyperstimulation IVF or ICSI (COH)? The comparison of simulated scenarios indicates that a strategy of three to six cycles of MNC with minimized medication is a cost-effective alternative for one cycle of COH with strict application of single embryo transfer (SET). MNC is cheaper per cycle than COH but also less effective in terms of live birth rate (LBR). However, strict application of SET in COH cycles reduces effectiveness and up to three MNC cycles can be performed at the same costs as one COH cycle. The cost-effectiveness of MNC versus COH was evaluated in three simulated treatment scenarios: three cycles of MNC versus one cycle of COH with SET or double embryo transfer (DET) and subsequent transfer of cryopreserved embryos (Scenario 1); six cycles of MNC versus one cycle of COH with strictly SET and subsequent transfer of cryopreserved embryos (Scenario 2); six cycles of MNC with minimized medication (hCG ovulation trigger only) versus one cycle of COH with SET or DET and subsequent transfer of cryopreserved embryos (Scenario 3). We used baseline data obtained from two retrospective cohorts of consecutive patients (2005-2008) undergoing MNC in the University Medical Center Groningen (n = 499, maximum six cycles per patient) or their first COH cycle with subsequent transfer of cryopreserved embryos in the Academic Medical Center Amsterdam (n = 392). Data from 1994 MNC cycles (958 MNC-IVF and 1036 MNC-ICSI) and 392 fresh COH cycles (one per patient, 196 COH-IVF and 196 COH-ICSI) with subsequent transfer of cryopreserved embryos (n = 72 and n = 94 in MNC and COH cycles, respectively) in ovulatory, subfertile women cost-effectiveness ratio (ICER) was calculated, defined as the ratio of the difference in IVF costs up to 6 weeks postpartum to the difference in LBR. Live birth was the primary outcome measure and was defined as the birth of at least one living child

  17. How to assess performance in cycling: the multivariate nature of influencing factors and related indicators

    Science.gov (United States)

    Castronovo, A. Margherita; Conforto, Silvia; Schmid, Maurizio; Bibbo, Daniele; D'Alessio, Tommaso

    2013-01-01

    Finding an optimum for the cycling performance is not a trivial matter, since the literature shows the presence of many controversial aspects. In order to quantify different levels of performance, several indexes have been defined and used in many studies, reflecting variations in physiological and biomechanical factors. In particular, indexes such as Gross Efficiency (GE), Net Efficiency (NE) and Delta Efficiency (DE) have been referred to changes in metabolic efficiency (EffMet), while the Indexes of Effectiveness (IE), defined over the complete crank revolution or over part of it, have been referred to variations in mechanical effectiveness (EffMech). All these indicators quantify the variations of different factors [i.e., muscle fibers type distribution, pedaling cadence, setup of the bicycle frame, muscular fatigue (MFat), environmental variables, ergogenic aids, psychological traits (PsychTr)], which, moreover, show high mutual correlation. In the attempt of assessing cycling performance, most studies in the literature keep all these factors separated. This may bring to misleading results, leaving unanswered the question of how to improve cycling performance. This work provides an overview on the studies involving indexes and factors usually related to performance monitoring and assessment in cycling. In particular, in order to clarify all those aspects, the mutual interactions among these factors are highlighted, in view of a global performance assessment. Moreover, a proposal is presented advocating for a model-based approach that considers all factors mentioned in the survey, including the mutual interaction effects, for the definition of an objective function E representing the overall effectiveness of a training program in terms of both EffMet and EffMech. PMID:23734130

  18. How to Assess Performance in Cycling: the Multivariate Nature of Influencing Factors and Related Indicators.

    Directory of Open Access Journals (Sweden)

    Anna Margherita eCastronovo

    2013-05-01

    Full Text Available Finding an optimum for the cycling performance is not a trivial matter, since the literature shows the presence of many controversial aspects. In order to quantify different levels of performance, several indexes have been defined and used in many studies, reflecting variations in physiological and biomechanical factors. In particular, indexes such as Gross Efficiency (GE, Net Efficiency (NE and Delta Efficiency (DE have been referred to changes in metabolic efficiency (EffMet, while the Indexes of Effectiveness (IE, defined over the complete crank revolution or over part of it, have been referred to variations in mechanical effectiveness (EffMech. All these indicators quantify the variations of different factors (i.e. muscle fibers type distribution, pedaling cadence, setup of the bicycle frame, muscular fatigue, environmental variables, ergogenic aids, psychological traits, which, moreover, show high mutual correlation. In the attempt of assessing cycling performance, most studies in the literature keep all these factors separated. This may bring to misleading results, leaving unanswered the question of how to improve cycling performance. This work provides an overview on the studies involving indexes and factors usually related to performance monitoring and assessment in cycling. In particular, in order to clarify all those aspects, the mutual interactions among these factors are highlighted, in view of a global performance assessment. Moreover, a proposal is presented advocating for a model-based approach that considers all factors mentioned in the survey, including the mutual interaction effects, for the definition of an objective function E representing the overall effectiveness of a training program in terms of both metabolic efficiency and mechanical effectiveness.

  19. Thermal enhancement of charge and discharge cycles for adsorbed natural gas storage

    KAUST Repository

    Rahman, Kazi Afzalur; Loh, Wai Soong; Chakraborty, Anutosh; Saha, Bidyut Baran; Chun, Won Gee; Ng, Kim Choon

    2011-01-01

    The usage of adsorbed natural gas (ANG) storage is hindered by the thermal management during the adsorption and desorption processes. An effective thermal enhancement is thus essential for the development of the ANG technology and the motivation

  20. Study on natural breeding sites of sand flies (Diptera: Phlebotominae) in areas of Leishmania transmission in Colombia.

    Science.gov (United States)

    Vivero, Rafael José; Torres-Gutierrez, Carolina; Bejarano, Eduar E; Peña, Horacio Cadena; Estrada, Luis Gregorio; Florez, Fernando; Ortega, Edgar; Aparicio, Yamileth; Muskus, Carlos E

    2015-02-22

    The location of the microhabitats where immature phlebotomine sand flies of the genus Lutzomyia develop is one of the least-known aspects of this group of medically important insects. For this reason strategies of source reduction approach for their control have not been possible in contrast to other insect vectors (such as mosquitoes), because their juvenile stages in terrestrial microhabitats is difficult to detect. Direct examination of soil samples, incubation of substrates and the use of emergence traps were the methods used to identify juvenile stages in 160 soil samples from urban and forest habitats within the foci of Leishmania transmission in Colombia. Immatures collected were identified subsequent from the rearing and emergence of adults using taxonomic keys or the analysis of the mitochondrial marker cytochrome oxidase I. Plant species associated with the natural breeding sites were identified and physicochemical properties of the soils were analyzed. A total of 38 (23.7%) sampling sites were identified as breeding sites, 142 phlebotomine sand flies were identified, belonging to 13 species of the genus Lutzomyia and two of Brumptomyia. The greatest numbers of immature were found within the tabular roots (51 immature sand flies from eight positive sites) and bases of trees (35 immature sand flies from 11 sites). The characterization and presence of the tree species (mainly Ceiba pentadra, Anacardium excelsum, Pseudosamanea guachapale) and the physicochemical properties (relative humidity and carbon/nitrogen ratio) of the soils associated with these breeding sites are significant factors in explaining the diversity and abundance of phlebotomine sand flies. Immature phlebotomine sand flies of the genus Lutzomyia in Colombia can be found in a wide variety of breeding sites rich in organic matter, high relative humidity and are associated with a typical vegetation of each locality. These results provide new perspectives for the study of the ecology of the

  1. Did Geomagnetic Activity Challenge Electric Power Reliability During Solar Cycle 23? Evidence from the PJM Regional Transmission Organization in North America

    Science.gov (United States)

    Forbes, Kevin F.; Cyr, Chris St

    2012-01-01

    During solar cycle 22, a very intense geomagnetic storm on 13 March 1989 contributed to the collapse of the Hydro-Quebec power system in Canada. This event clearly demonstrated that geomagnetic storms have the potential to lead to blackouts. This paper addresses whether geomagnetic activity challenged power system reliability during solar cycle 23. Operations by PJM Interconnection, LLC (hereafter PJM), a regional transmission organization in North America, are examined over the period 1 April 2002 through 30 April 2004. During this time PJM coordinated the movement of wholesale electricity in all or parts of Delaware, Maryland, New Jersey, Ohio, Pennsylvania, Virginia, West Virginia, and the District of Columbia in the United States. We examine the relationship between a proxy of geomagnetically induced currents (GICs) and a metric of challenged reliability. In this study, GICs are proxied using magnetometer data from a geomagnetic observatory located just outside the PJM control area. The metric of challenged reliability is the incidence of out-of-economic-merit order dispatching due to adverse reactive power conditions. The statistical methods employed make it possible to disentangle the effects of GICs on power system operations from purely terrestrial factors. The results of the analysis indicate that geomagnetic activity can significantly increase the likelihood that the system operator will dispatch generating units based on system stability considerations rather than economic merit.

  2. Externalities of fuel cycles 'ExternE' project. Natural gas fuel cycle. Estimation of physical impacts and monetary valuation for priority impact pathways

    International Nuclear Information System (INIS)

    Holland, M.; Watkiss, P.; Berry, J.; Johnson, C.; Lee, D.

    1994-01-01

    This document assesses the progress made in quantifying environmental and health damages associated with the natural gas fuel cycle for electricity generation. The methodology developed in the ExternE Project is described in more detail elsewhere (European Commission, 1994a; 1995, in preparation). The reader is referred to these earlier reports for wider discussion of many of the issues underlying this type of work. The increased desire for economic assessment of environmental damage reflects growing awareness of problems such as global warming, ozone depletion and the acidification and nutrification of ecosystems. A wide range of receptors are affected, including human health, forests, crops, and buildings. Such damages are typically not accounted for by the producers and consumers of the good in question (in this case energy). They are thus referred to as 'external costs' or 'externalities', to distinguish them from the private costs which account for the construction of plant, cost of fuel, wages, etc. At the political level there are a variety of reasons for the growing interest in the quantification of the environmental impacts of energy use and the related external costs. These include the need to integrate environmental concerns when selecting between different fuels and energy technologies and the need to evaluate the costs and benefits of stricter environmental standards. These issues are reflected in European Union policy, through, for example, the Maastricht Treaty, the 5th Environmental Action Programme 'towards sustainability', the European Commission's White Paper 'Growth, competitiveness, employment and ways forward to the 21st century' and the establishment of the European Environmental Agency. The proposal for an Energy-Carbon tax is the first concrete proposal by the European Union for the direct use of economic instruments in environmental policy in the energy sector. An agreed methodology for calculation and integration of external costs has not

  3. Prospects for energy efficiency improvement and reduction of emissions and life cycle costs for natural gas vehicles

    Science.gov (United States)

    Kozlov, A. V.; Terenchenko, A. S.; Luksho, V. A.; Karpukhin, K. E.

    2017-01-01

    This work is devoted to the experimental investigation of the possibilities to reduce greenhouse gas emissions and to increase energy efficiency of engines that use natural gas as the main fuel and the analysis of economic efficiency of use of dual fuel engines in vehicles compared to conventional diesel. The results of experimental investigation of a 190 kW dual-fuel engine are presented; it is shown that quantitative and qualitative working process control may ensure thermal efficiency at the same level as that of the diesel engine and in certain conditions 5...8% higher. The prospects for reduction of greenhouse gas emissions have been assessed. The technical and economic evaluation of use of dual fuel engines in heavy-duty vehicles has been performed, taking into account the total life cycle. It is shown that it is possible to reduce life cycle costs by two times.

  4. Hydrologic connectivity to streams increases nitrogen and phosphorus inputs and cycling in soils of created and natural floodplain wetlands

    Science.gov (United States)

    Wolf, Kristin L.; Noe, Gregory; Ahn, Changwoo

    2013-01-01

    Greater connectivity to stream surface water may result in greater inputs of allochthonous nutrients that could stimulate internal nitrogen (N) and phosphorus (P) cycling in natural, restored, and created riparian wetlands. This study investigated the effects of hydrologic connectivity to stream water on soil nutrient fluxes in plots (n = 20) located among four created and two natural freshwater wetlands of varying hydrology in the Piedmont physiographic province of Virginia. Surface water was slightly deeper; hydrologic inputs of sediment, sediment-N, and ammonium were greater; and soil net ammonification, N mineralization, and N turnover were greater in plots with stream water classified as their primary water source compared with plots with precipitation or groundwater as their primary water source. Soil water-filled pore space, inputs of nitrate, and soil net nitrification, P mineralization, and denitrification enzyme activity (DEA) were similar among plots. Soil ammonification, N mineralization, and N turnover rates increased with the loading rate of ammonium to the soil surface. Phosphorus mineralization and ammonification also increased with sedimentation and sediment-N loading rate. Nitrification flux and DEA were positively associated in these wetlands. In conclusion, hydrologic connectivity to stream water increased allochthonous inputs that stimulated soil N and P cycling and that likely led to greater retention of sediment and nutrients in created and natural wetlands. Our findings suggest that wetland creation and restoration projects should be designed to allow connectivity with stream water if the goal is to optimize the function of water quality improvement in a watershed.

  5. Impaired Cell Cycle Regulation in a Natural Equine Model of Asthma.

    Directory of Open Access Journals (Sweden)

    Alicja Pacholewska

    Full Text Available Recurrent airway obstruction (RAO is a common and potentially debilitating lower airway disease in horses, which shares many similarities with human asthma. In susceptible horses RAO exacerbation is caused by environmental allergens and irritants present in hay dust. The objective of this study was the identification of genes and pathways involved in the pathology of RAO by global transcriptome analyses in stimulated peripheral blood mononuclear cells (PBMCs. We performed RNA-seq on PBMCs derived from 40 RAO affected and 45 control horses belonging to three cohorts of Warmblood horses: two half-sib families and one group of unrelated horses. PBMCs were stimulated with hay dust extract, lipopolysaccharides, a recombinant parasite antigen, or left unstimulated. The total dataset consisted of 561 individual samples. We detected significant differences in the expression profiles between RAO and control horses. Differential expression (DE was most marked upon stimulation with hay dust extract. An important novel finding was a strong upregulation of CXCL13 together with many genes involved in cell cycle regulation in stimulated samples from RAO affected horses, in addition to changes in the expression of several HIF-1 transcription factor target genes. The RAO condition alters systemic changes observed as differential expression profiles of PBMCs. Those changes also depended on the cohort and stimulation of the samples and were dominated by genes involved in immune cell trafficking, development, and cell cycle regulation. Our findings indicate an important role of CXCL13, likely macrophage or Th17 derived, and the cell cycle regulator CDC20 in the immune response in RAO.

  6. Evaluation of the physical dew point in the economizer of a combined cycle burning natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Pena, F.; Blanco, J.M. [Universidad del Pais Vasco/E.H.U. Alameda de Urquijo s/n, Bilbao (Spain). Dpto. Maquinas y Motores Termicos, Escuela Sup. de Ingenieria

    2007-08-15

    Natural gas contents a considerable percentage of hydrogen, so is obvious to expect an amount of water vapour in its combustion exhaust gases, which would raise the dew point temperature. That means a higher speed of corrosion over the whole exposed physical area, which could represent a serious risk of breakdown, especially in pressurized hot-water equipments. In this work, a new methodology for determining the physical dew point inside a economizer depending on the fuel type burned (in this case is natural gas) has been developed. The calculation of the total amount of condensed water has also been carried out as well as the localization of the area where this condensation occurs. Acid dew point has not been taken into account here although exhaust gases are acidic, due mainly to the low sulphur content which is almost undetectable when burning natural gas, but it will be performed in a later study coming soon. (author)

  7. Spatial and Temporal Analyses of Environmental Affects on Zizania Palustris and Its Natural Cycles

    Science.gov (United States)

    Rickman, Douglas L.; Greensky, Wayne; Al-Hamdan, M. Z.; Estes, M. G.; Crosson, W. L.; Estes, Sue M.

    2017-01-01

    As part of a joint education and research effort funded by NASA, research studies were initiated involving students associated with the Ojibwe and researchers at Marshall Space Flight Center. Topics were chosen that satisfied the nature of the work proposed and were tractable, given the student's constraints (abilities, interests, and time). One of the studies, which spanned two summers, examined some potential environmental effects on northern wild rice in northern Wisconsin. The rice of interest is naturally occurring ('wild' wild rice), as opposed to cultivated wild rice ('paddy' wild rice).

  8. Natural history of Ctenus medius Keyserling, 1891 (Aranae, Ctenidae) II: life cycle and aspects of reproductive behavior under laboratory conditions

    OpenAIRE

    FOLLY-RAMOS E.; ALMEIDA C. E.; CARMO-SILVA M.; COSTA J.

    2002-01-01

    Ctenus medius Keyserling, 1891 is a wandering spider common in the Brazilian Atlantic Forest. It has been the subject of few studies. Thus, this work aims to elucidate aspects of its natural history, such as the life cycle and reproductive behavior of this species, through laboratory and field observations. Two females with egg sacs were observed in the laboratory and one was observed in field (Barra Mansa, 22º32'S and 44º10'W) until the emergence of the spiderlings. For observation of the im...

  9. Life Cycle Assessment of Producing Electricity in Thailand: A Case Study of Natural Gas Power Plant

    Directory of Open Access Journals (Sweden)

    Usapein Parnuwat

    2017-01-01

    Full Text Available Environmental impacts from natural gas power plant in Thailand was investigated in this study. The objective was to identify the hotspot of environmental impact from electricity production and the allocation of emissions from power plant was studied. All stressors to environment were collected for annual natural gas power plant operation. The allocation of environmental load between electricity and steam was done by WRI/WBCSD method. Based on the annual power plant operation, the highest of environmental impact was fuel combustion, followed by natural gas extraction, and chemical reagent. After allocation, the result found that 1 kWh of electricity generated 0.425 kgCO2eq and 1 ton of steam generated 225 kgCO2eq. When compared based on 1GJ of energy product, the result showed that the environmental impact of electricity is higher than steam product. To improve the environmental performance, it should be focused on the fuel combustion, for example, increasing the efficiency of gas turbine, and using low sulphur content of natural gas. This result can be used as guideline for stakeholder who engage with the environmental impact from power plant; furthermore, it can be useful for policy maker to understand the allocation method between electricity and steam products.

  10. Towards harmonizing natural resources as an area of protection in life cycle impact assessment

    DEFF Research Database (Denmark)

    Sonderegger, Thomas; Dewulf, Jo; Fantke, Peter

    2017-01-01

    categories, nor do existing methods and models addressing different natural resource categories do so in a consistent way across categories. Exceptions are exergy and solar energy-related methods, which cover the widest range of resource categories. However, these methods do not link exergy consumption...

  11. Force transmissibility versus displacement transmissibility

    Science.gov (United States)

    Lage, Y. E.; Neves, M. M.; Maia, N. M. M.; Tcherniak, D.

    2014-10-01

    It is well-known that when a single-degree-of-freedom (sdof) system is excited by a continuous motion of the foundation, the force transmissibility, relating the force transmitted to the foundation to the applied force, equals the displacement transmissibility. Recent developments in the generalization of the transmissibility to multiple-degree-of-freedom (mdof) systems have shown that similar simple and direct relations between both types of transmissibility do not appear naturally from the definitions, as happens in the sdof case. In this paper, the authors present their studies on the conditions under which it is possible to establish a relation between force transmissibility and displacement transmissibility for mdof systems. As far as the authors are aware, such a relation is not currently found in the literature, which is justified by being based on recent developments in the transmissibility concept for mdof systems. Indeed, it does not appear naturally, but the authors observed that the needed link is present when the displacement transmissibility is obtained between the same coordinates where the applied and reaction forces are considered in the force transmissibility case; this implies that the boundary conditions are not exactly the same and instead follow some rules. This work presents a formal derivation of the explicit relation between the force and displacement transmissibilities for mdof systems, and discusses its potential and limitations. The authors show that it is possible to obtain the displacement transmissibility from measured forces, and the force transmissibility from measured displacements, opening new perspectives, for example, in the identification of applied or transmitted forces. With this novel relation, it becomes possible, for example, to estimate the force transmissibility matrix with the structure off its supports, in free boundary conditions, and without measuring the forces. As far as force identification is concerned, this

  12. Organic Rankine Cycle for Residual Heat to Power Conversion in Natural Gas Compressor Station. Part I: Modelling and Optimisation Framework

    Science.gov (United States)

    Chaczykowski, Maciej

    2016-06-01

    Basic organic Rankine cycle (ORC), and two variants of regenerative ORC have been considered for the recovery of exhaust heat from natural gas compressor station. The modelling framework for ORC systems has been presented and the optimisation of the systems was carried out with turbine power output as the variable to be maximized. The determination of ORC system design parameters was accomplished by means of the genetic algorithm. The study was aimed at estimating the thermodynamic potential of different ORC configurations with several working fluids employed. The first part of this paper describes the ORC equipment models which are employed to build a NLP formulation to tackle design problems representative for waste energy recovery on gas turbines driving natural gas pipeline compressors.

  13. The Externe project. Assessment of the external costs of the natural gas fuel cycle

    International Nuclear Information System (INIS)

    Holland, M.R.

    1997-01-01

    A detailed bottom-up methodology for assessment of the external costs of energy has been developed by a multi-disciplinary, pan-European team as part of the European Commissions's JOULE Programme. The consequences of the generation of electricity from fossil, nuclear and renewable technologies, in terms of damages to human health, buildings and the wider environment, have been assessed within a consistent framework. The potential application of the results in cost-benefit analysis, power system optimisation, emissions charging, etc. is also now under investigation. The analysis starts with definition of the fuel cycle, and specification of the technologies and locations to be considered. Results to date show that for typical modern examples of power plants burning different fossil fuels, externalities (including possible global warming effects) are lowest for gas-burning plant. (R.P.)

  14. Impact of anthropogenic and natural environmental changes on Echinococcus transmission in Ningxia Hui Autonomous Region, the People’s Republic of China

    Science.gov (United States)

    2012-01-01

    Echinococcus transmission is known to be affected by various environmental factors, which may be modified by human influence or natural events including global warming. Considerable population growth in the last fifty years in Ningxia Hui Autonomous Region (NHAR), the People’s Republic of China (PRC), has led to dramatic increases in deforestation and modified agricultural practices. In turn, this has resulted in many changes in the habitats for the definitive and intermediate hosts of both Echinococcus granulosus and E. multilocularis, which have increased the risks for transmission of both parasites, affecting echinococcosis prevalence and human disease. Ecological environmental changes due to anthropogenic activities and natural events drive Echinococcus transmission and NHAR provides a notable example illustrating how human activity can impact on a parasitic infection of major public health significance. It is very important to continually monitor these environmental (including climatic) factors that drive the distribution of Echinococcus spp. and their impact on transmission to humans because such information is necessary to formulate reliable future public health policy for echinococcosis control programs and to prevent disease spread. PMID:22827890

  15. Impact of anthropogenic and natural environmental changes on Echinococcus transmission in Ningxia Hui Autonomous Region, the People’s Republic of China

    Directory of Open Access Journals (Sweden)

    Yang Yu

    2012-07-01

    Full Text Available Abstract Echinococcus transmission is known to be affected by various environmental factors, which may be modified by human influence or natural events including global warming. Considerable population growth in the last fifty years in Ningxia Hui Autonomous Region (NHAR, the People’s Republic of China (PRC, has led to dramatic increases in deforestation and modified agricultural practices. In turn, this has resulted in many changes in the habitats for the definitive and intermediate hosts of both Echinococcus granulosus and E. multilocularis, which have increased the risks for transmission of both parasites, affecting echinococcosis prevalence and human disease. Ecological environmental changes due to anthropogenic activities and natural events drive Echinococcus transmission and NHAR provides a notable example illustrating how human activity can impact on a parasitic infection of major public health significance. It is very important to continually monitor these environmental (including climatic factors that drive the distribution of Echinococcus spp. and their impact on transmission to humans because such information is necessary to formulate reliable future public health policy for echinococcosis control programs and to prevent disease spread.

  16. Differences in microbial community structure and nitrogen cycling in natural and drained tropical peatland soils.

    Science.gov (United States)

    Espenberg, Mikk; Truu, Marika; Mander, Ülo; Kasak, Kuno; Nõlvak, Hiie; Ligi, Teele; Oopkaup, Kristjan; Maddison, Martin; Truu, Jaak

    2018-03-16

    Tropical peatlands, which play a crucial role in the maintenance of different ecosystem services, are increasingly drained for agriculture, forestry, peat extraction and human settlement purposes. The present study investigated the differences between natural and drained sites of a tropical peatland in the community structure of soil bacteria and archaea and their potential to perform nitrogen transformation processes. The results indicate significant dissimilarities in the structure of soil bacterial and archaeal communities as well as nirK, nirS, nosZ, nifH and archaeal amoA gene-possessing microbial communities. The reduced denitrification and N 2 -fixing potential was detected in the drained tropical peatland soil. In undisturbed peatland soil, the N 2 O emission was primarily related to nirS-type denitrifiers and dissimilatory nitrate reduction to ammonium, while the conversion of N 2 O to N 2 was controlled by microbes possessing nosZ clade I genes. The denitrifying microbial community of the drained site differed significantly from the natural site community. The main reducers of N 2 O were microbes harbouring nosZ clade II genes in the drained site. Additionally, the importance of DNRA process as one of the controlling mechanisms of N 2 O fluxes in the natural peatlands of the tropics revealed from the results of the study.

  17. Design and optimisation of organic Rankine cycles for waste heat recovery in marine applications using the principles of natural selection

    International Nuclear Information System (INIS)

    Larsen, Ulrik; Pierobon, Leonardo; Haglind, Fredrik; Gabrielii, Cecilia

    2013-01-01

    Power cycles using alternative working fluids are currently receiving significant attention. Selection of working fluid among many candidates is a key topic and guidelines have been presented. A general problem is that the selection is based on numerous criteria, such as thermodynamic performance, boundary conditions, hazard levels and environmental concerns. A generally applicable methodology, based on the principles of natural selection, is presented and used to determine the optimum working fluid, boiler pressure and Rankine cycle process layout for scenarios related to marine engine heat recovery. Included in the solution domain are 109 fluids in sub and supercritical processes, and the process is adapted to the properties of the individual fluid. The efficiency losses caused by imposing process constraints are investigated to help propose a suitable process layout. Hydrocarbon dry type fluids in recuperated processes produced the highest efficiencies, while wet and isentropic fluids were superior in non-recuperated processes. The results suggested that at design point, the requirements of process simplicity, low operating pressure and low hazard resulted in cumulative reductions in cycle efficiency. Furthermore, the results indicated that non-flammable fluids were able to produce near optimum efficiency in recuperated high pressure processes

  18. Predicting the ultimate potential of natural gas SOFC power cycles with CO2 capture - Part A: Methodology and reference cases

    Science.gov (United States)

    Campanari, Stefano; Mastropasqua, Luca; Gazzani, Matteo; Chiesa, Paolo; Romano, Matteo C.

    2016-08-01

    Driven by the search for the highest theoretical efficiency, in the latest years several studies investigated the integration of high temperature fuel cells in natural gas fired power plants, where fuel cells are integrated with simple or modified Brayton cycles and/or with additional bottoming cycles, and CO2 can be separated via chemical or physical separation, oxy-combustion and cryogenic methods. Focusing on Solid Oxide Fuel Cells (SOFC) and following a comprehensive review and analysis of possible plant configurations, this work investigates their theoretical potential efficiency and proposes two ultra-high efficiency plant configurations based on advanced intermediate-temperature SOFCs integrated with a steam turbine or gas turbine cycle. The SOFC works at atmospheric or pressurized conditions and the resulting power plant exceeds 78% LHV efficiency without CO2 capture (as discussed in part A of the work) and 70% LHV efficiency with substantial CO2 capture (part B). The power plants are simulated at the 100 MW scale with a complete set of realistic assumptions about fuel cell (FC) performance, plant components and auxiliaries, presenting detailed energy and material balances together with a second law analysis.

  19. A natural light/dark cycle regulation of carbon-nitrogen metabolism and gene expression in rice shoots

    Directory of Open Access Journals (Sweden)

    Haixing Li

    2016-08-01

    Full Text Available Light and temperature are two particularly important environmental cues for plant survival. Carbon and nitrogen are two essential macronutrients required for plant growth and development, and cellular carbon and nitrogen metabolism must be tightly coordinated. In order to understand how the natural light/dark cycle regulates carbon and nitrogen metabolism in rice plants, we analyzed the photosynthesis, key carbon-nitrogen metabolites and enzyme activities, and differentially expressed genes and miRNAs involved in the carbon and nitrogen metabolic pathway in rice shoots at the following times: 2:00, 6:00, 10:00, 14:00, 18:00 and 22:00. Our results indicated that more CO2 was fixed into carbohydrates by a high net photosynthetic rate, respiratory rate and stomatal conductance in the daytime. Although high levels of the nitrate reductase activity, free ammonium and carbohydrates were exhibited in the daytime, the protein synthesis was not significantly facilitated by the light and temperature. In mRNA sequencing, the carbon and nitrogen metabolism-related differentially expressed genes were obtained, which could be divided into eight groups: photosynthesis, TCA cycle, sugar transport, sugar metabolism, nitrogen transport, nitrogen reduction, amino acid metabolism and nitrogen regulation. Additionally, a total of 78,306 alternative splicing events have been identified, which primarily belong to alternative 5' donor sites, alternative 3' acceptor sites, intron retention and exon skipping. In sRNA sequencing, four carbon and nitrogen metabolism-related miRNAs (osa-miR1440b, osa-miR2876-5p, osa-miR1877 and osa-miR5799 were determined to be regulated by natural light/dark cycle. The expression level analysis showed that the four carbon and nitrogen metabolism-related miRNAs negatively regulated their target genes. These results may provide a good strategy to study how natural light/dark cycle regulates carbon and nitrogen metabolism to ensure plant

  20. Hormonal predictors of women's extra-pair vs. in-pair sexual attraction in natural cycles: Implications for extended sexuality.

    Science.gov (United States)

    Grebe, Nicholas M; Emery Thompson, Melissa; Gangestad, Steven W

    2016-02-01

    In naturally cycling women, Roney and Simmons (2013) examined hormonal correlates of their desire for sexual contact. Estradiol was positively associated, and progesterone negatively associated, with self-reported desire. The current study extended these findings by examining, within a sample of 33 naturally cycling women involved in romantic relationships, hormonal correlates of sexual attraction to or interests in specific targets: women's own primary partner or men other than women's primary partner. Women's sexual interests and hormone (estradiol, progesterone, and testosterone) levels were assessed at two different time points. Whereas estradiol levels were associated with relatively greater extra-pair sexual interests than in-pair sexual interests, progesterone levels were associated with relatively greater in-pair sexual interests. Both hormones specifically predicted in-pair sexual desire, estradiol negatively and progesterone positively. These findings have implications for understanding the function of women's extended sexuality - their sexual proceptivity and receptivity outside the fertile phase, especially during the luteal phase. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Sedimentary organic matter distributions, burrowing activity, and biogeochemical cycling: Natural patterns and experimental artifacts

    Science.gov (United States)

    Michaud, Emma; Aller, Robert, C.; Stora, Georges

    2010-11-01

    The coupling between biogenic reworking activity and reactive organic matter patterns within deposits is poorly understood and often ignored. In this study, we examined how common experimental treatments of sediment affect the burrowing behavior of the polychaete Nephtys incisa and how these effects may interact with reactive organic matter distributions to alter diagenetic transport - reaction balances. Sediment and animals were recovered from a subtidal site in central Long Island Sound, USA. The upper 15 cm of the sediment was sectioned into sub-intervals, and each interval separately sieved and homogenized. Three initial distributions of sediment and organic substrate reactivity were setup in a series of microcosms: (1) a reconstituted natural pattern with surface-derived sediment overlying sediment obtained from progressively deeper material to a depth of 15 cm (Natural); (2) a 15 cm thick sediment layer composed only of surface-derived sediment (Rich); and (3) a 15 cm thick layer composed of uniformally mixed sediment from the original 15 cm sediment profile (Averaged). The two last treatments are comparable to that used in microcosms in many previous studies of bioturbation and interspecific functional interaction experiments. Sediment grain size distributions were 97.5% silt-clay and showed no depth dependent patterns. Sediment porosity gradients were slightly altered by the treatments. Nepthys were reintroduced and aquariums were X-rayed regularly over 5 months to visualize and quantify spatial and temporal dynamics of burrows. The burrowing behaviour of adult populations having similar total biovolume, biomass, abundance, and individual sizes differed substantially as a function of treatment. Burrows in sediment with natural property gradients were much shallower and less dense than those in microcosms with altered gradients. The burrow volume/biovolume ratio was also lower in the substrate with natural organic reactivity gradients. Variation in food

  2. Effects of Climate and Ecosystem Disturbances on Biogeochemical Cycling in a Semi-Natural Terrestrial Ecosystem

    International Nuclear Information System (INIS)

    Beier, Claus; Schmidt, Inger Kappel; Kristensen, Hanne Lakkenborg

    2004-01-01

    The effects of increased temperature and potential ecosystem disturbances on biogeochemical cycling were investigated by manipulation of temperature in a mixed Calluna/grass heathland in Denmark. A reflective curtain covered the vegetation during the night to reduce the heat loss of IR radiation from the ecosystem to the atmosphere. This 'night time warming' was done for 3 years and warmed the air and soil by 1.1 deg. C. Warming was combined with ecosystem disturbances, including infestation by Calluna heather beetles (Lochmaea suturalis Thompson) causing complete defoliation of Calluna leaves during the summer 2000, and subsequent harvesting of all aboveground biomass during the autumn. Small increases in mineralisation rates were induced by warming and resulted in increased leaching of nitrogen from the organic soil layer. The increased nitrogen leaching from the organic soil layer was re-immobilised in the mineral soil layer as warming stimulated plant growth and thereby increased nitrogen immobilisation. Contradictory to the generally moderate effects of warming, the heather beetle infestation had very strong effects on mineralisation rates and the plant community. The grasses completely out-competed the Calluna plants which had not re-established two years after the infestation, probably due to combined effects of increased nutrient availability and the defoliation of Calluna. On the short term, ecosystem disturbances may have very strong effects on internal ecosystem processes and plant community structure compared to the more long-term effects of climate change

  3. Natural and experimental hepatitis E virus genotype 3-infection in European wild boar is transmissible to domestic pigs.

    Science.gov (United States)

    Schlosser, Josephine; Eiden, Martin; Vina-Rodriguez, Ariel; Fast, Christine; Dremsek, Paul; Lange, Elke; Ulrich, Rainer G; Groschup, Martin H

    2014-11-26

    Hepatitis E virus (HEV) is the causative agent of acute hepatitis E in humans in developing countries, but sporadic and autochthonous cases do also occur in industrialised countries. In Europe, food-borne zoonotic transmission of genotype 3 (gt3) has been associated with domestic pig and wild boar. However, little is known about the course of HEV infection in European wild boar and their role in HEV transmission to domestic pigs. To investigate the transmissibility and pathogenesis of wild boar-derived HEVgt3, we inoculated four wild boar and four miniature pigs intravenously. Using quantitative real-time RT-PCR viral RNA was detected in serum, faeces and in liver, spleen and lymph nodes. The antibody response evolved after fourteen days post inoculation. Histopathological findings included mild to moderate lymphoplasmacytic hepatitis which was more prominent in wild boar than in miniature pigs. By immunohistochemical methods, viral antigens were detected mainly in Kupffer cells and liver sinusoidal endothelial cells, partially associated with hepatic lesions, but also in spleen and lymph nodes. While clinical symptoms were subtle and gross pathology was inconspicuous, increased liver enzyme levels in serum indicated hepatocellular injury. As the faecal-oral route is supposed to be the most likely transmission route, we included four contact animals to prove horizontal transmission. Interestingly, HEVgt3-infection was also detected in wild boar and miniature pigs kept in contact to intravenously inoculated wild boar. Given the high virus loads and long duration of viral shedding, wild boar has to be considered as an important HEV reservoir and transmission host in Europe.

  4. Hydrologic connectivity to streams increases nitrogen and phosphorus inputs and cycling in soils of created and natural floodplain wetlands.

    Science.gov (United States)

    Wolf, Kristin L; Noe, Gregory B; Ahn, Changwoo

    2013-07-01

    Greater connectivity to stream surface water may result in greater inputs of allochthonous nutrients that could stimulate internal nitrogen (N) and phosphorus (P) cycling in natural, restored, and created riparian wetlands. This study investigated the effects of hydrologic connectivity to stream water on soil nutrient fluxes in plots ( = 20) located among four created and two natural freshwater wetlands of varying hydrology in the Piedmont physiographic province of Virginia. Surface water was slightly deeper; hydrologic inputs of sediment, sediment-N, and ammonium were greater; and soil net ammonification, N mineralization, and N turnover were greater in plots with stream water classified as their primary water source compared with plots with precipitation or groundwater as their primary water source. Soil water-filled pore space, inputs of nitrate, and soil net nitrification, P mineralization, and denitrification enzyme activity (DEA) were similar among plots. Soil ammonification, N mineralization, and N turnover rates increased with the loading rate of ammonium to the soil surface. Phosphorus mineralization and ammonification also increased with sedimentation and sediment-N loading rate. Nitrification flux and DEA were positively associated in these wetlands. In conclusion, hydrologic connectivity to stream water increased allochthonous inputs that stimulated soil N and P cycling and that likely led to greater retention of sediment and nutrients in created and natural wetlands. Our findings suggest that wetland creation and restoration projects should be designed to allow connectivity with stream water if the goal is to optimize the function of water quality improvement in a watershed. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  5. Temporal Stability of the Microbial Community in Sewage-Polluted Seawater Exposed to Natural Sunlight Cycles and Marine Microbiota

    Science.gov (United States)

    Sassoubre, Lauren M.; Yamahara, Kevan M.

    2015-01-01

    Billions of gallons of untreated wastewater enter the coastal ocean each year. Once sewage microorganisms are in the marine environment, they are exposed to environmental stressors, such as sunlight and predation. Previous research has investigated the fate of individual sewage microorganisms in seawater but not the entire sewage microbial community. The present study used next-generation sequencing (NGS) to examine how the microbial community in sewage-impacted seawater changes over 48 h when exposed to natural sunlight cycles and marine microbiota. We compared the results from microcosms composed of unfiltered seawater (containing naturally occurring marine microbiota) and filtered seawater (containing no marine microbiota) to investigate the effect of marine microbiota. We also compared the results from microcosms that were exposed to natural sunlight cycles with those from microcosms kept in the dark to investigate the effect of sunlight. The microbial community composition and the relative abundance of operational taxonomic units (OTUs) changed over 48 h in all microcosms. Exposure to sunlight had a significant effect on both community composition and OTU abundance. The effect of marine microbiota, however, was minimal. The proportion of sewage-derived microorganisms present in the microcosms decreased rapidly within 48 h, and the decrease was the most pronounced in the presence of both sunlight and marine microbiota, where the proportion decreased from 85% to 3% of the total microbial community. The results from this study demonstrate the strong effect that sunlight has on microbial community composition, as measured by NGS, and the importance of considering temporal effects in future applications of NGS to identify microbial pollution sources. PMID:25576619

  6. [Biogeochemical cycles in natural forest and conifer plantations in the high mountains of Colombia].

    Science.gov (United States)

    León, Juan Diego; González, María Isabel; Gallardo, Juan Fernando

    2011-12-01

    Plant litter production and decomposition are two important processes in forest ecosystems, since they provide the main organic matter input to soil and regulate nutrient cycling. With the aim to study these processes, litterfall, standing litter and nutrient return were studied for three years in an oak forest (Quercus humboldtii), pine (Pinus patula) and cypress (Cupressus lusitanica) plantations, located in highlands of the Central Cordillera of Colombia. Evaluation methods included: fine litter collection at fortnightly intervals using litter traps; the litter layer samples at the end of each sampling year and chemical analyses of both litterfall and standing litter. Fine litter fall observed was similar in oak forest (7.5 Mg ha/y) and in pine (7.8 Mg ha/y), but very low in cypress (3.5 Mg ha/y). Litter standing was 1.76, 1.73 and 1.3 Mg ha/y in oak, pine and cypress, respectively. The mean residence time of the standing litter was of 3.3 years for cypress, 2.1 years for pine and 1.8 years for oak forests. In contrast, the total amount of retained elements (N, P, S, Ca, Mg, K, Cu, Fe, Mn and Zn) in the standing litter was higher in pine (115 kg/ha), followed by oak (78 kg/ha) and cypress (24 kg/ha). Oak forests showed the lowest mean residence time of nutrients and the highest nutrients return to the soil as a consequence of a faster decomposition. Thus, a higher nutrient supply to soils from oaks than from tree plantations, seems to be an ecological advantage for recovering and maintaining the main ecosystem functioning features, which needs to be taken into account in restoration programs in this highly degraded Andean mountains.

  7. Presence and patterns of alkaline phosphatase activity and phosphorus cycling in natural riparian zones under changing nutrient conditions

    Directory of Open Access Journals (Sweden)

    Peifang Wang

    2014-08-01

    Full Text Available Phosphorus (P is an important limiting nutrient in aquatic ecosystems and knowledge of P cycling is fundamental for reducing harmful algae blooms and other negative effects in water. Despite their importance, the characteristics of P cycling under changing nutrient conditions in shallow lakes were poorly investigated. In this study, in situ incubation experiments were conducted in a natural riparian zone in the main diversion channel used for water transfer into Lake Taihu (Wangyu River. Variations in microbial biomass, dissolved P fractions (organic and inorganic, and alkaline phosphatase activity (bulk APA and specific APA were determined after incubation with and without the addition of P and nitrogen (N (4 total water treatments: +P, +N, +NP, and control. Experiments were conducted during two seasons (late spring and early fall to account for natural differences in nutrient levels that may occur in situ. Our results demonstrated that low levels of DRP may not necessarily indicate P limitation. Phytoplankton exhibited “serial N limitation with P stress” in May, such that chlorophyll a (Chl a increased significantly with N addition, while the limiting nutrient shifted to P in October and phytoplankton biomass increased with P addition. Phytoplankton contributed greatly to APA production and was significantly influenced by P bioavailability, yet high levels of bulk APA were also not necessarily indicative of P limitation. In contrast to phytoplankton, bacteria were less P stressed. As a consequence of enhanced utilization of dissolved reactive P (DRP and dissolved organic P (DOP, +N treatment elevated APA significantly. By contrast, APA could be repressed to low values and phytoplankton converted a large portion of DRP to DOP with P addition. But this was not consistent with bacteria APA (bact-APA in the absence or presence of abundant phytoplankton biomass. The correlation between bulk APA and DRP was good at separate sites and discrepant

  8. Transmission patterns of smallpox: Systematic review of natural outbreaks in Europe and North America since World War II

    NARCIS (Netherlands)

    V. Bhatnagar (Vibha); M.A. Stoto (Michael); S.C. Morton (Sally); R. Boer (Rob); S.A. Bozzette (Samuel)

    2006-01-01

    textabstractBackground: Because smallpox (variola major) may be used as a biological weapon, we reviewed outbreaks in post-World War II Europe and North America in order to understand smallpox transmission patterns. Methods: A systematic review was used to identify papers from the National Library

  9. Comparative evaluation of a natural gas expansion plant integrated with an IC engine and an organic Rankine cycle

    International Nuclear Information System (INIS)

    Kostowski, Wojciech J.; Usón, Sergio

    2013-01-01

    Highlights: • Comparison of natural gas expansion systems integrated with gas boiler, ICE and ORC. • Expansion systems replace the throttling process in pressure regulating stations. • 5 System performance indicators based on the 1st and 2nd law are defined. • Exergy efficiency was calculated from the fuel-product approach. • ORC system yields highest exergy efficiency 52.6% and performance ratio of 0.771. - Abstract: The aim of the paper is to propose and evaluate an innovative exergy recovery system for natural gas expansion, based on the integration of an internal combustion engine (ICE) and an organic Rankine cycle (ORC), and to compare it with other alternatives. Natural gas expansion plants are a substantial improvement to the conventional gas pressure reduction stations, based on the throttling process, since the available physical exergy of pressurized gas is converted into mechanical energy by means of an expansion machine (turbine or piston expander) instead of being lost in the throttling process. However, due to the hydrate formation problem the gas has to be pre-heated prior to the expansion, which diminishes the system performance. An efficient method for performing this pre-heating is by the proposed system that comprises an ICE and an ORC: Pre-heating of natural gas is carried out partially directly by the co-generation module, via the engine cooling cycle, and partially indirectly, by means of the engine exhaust gases, which supply heat for the ORC, while the ORC condenser is connected with the lowest stage of natural gas pre-heating. Other alternatives are the use of an ICE without ORC, the use of a boiler, and even expansion in a throttling valve. The paper evaluates the performance of the aforementioned four configurations by means of both energy and exergy analysis. Several alternative performance indicators have been defined, calculated and discussed. Sources of irreversibilities have been identified by means of exergy analysis

  10. Life cycle assessment of fuels for district heating: A comparison of waste incineration, biomass- and natural gas combustion

    International Nuclear Information System (INIS)

    Eriksson, Ola; Finnveden, Goeran; Ekvall, Tomas; Bjoerklund, Anna

    2007-01-01

    The aim of this consequential life cycle assessment (LCA) is to compare district heating based on waste incineration with combustion of biomass or natural gas. The study comprises two options for energy recovery (combined heat and power (CHP) or heat only), two alternatives for external, marginal electricity generation (fossil lean or intense), and two alternatives for the alternative waste management (landfill disposal or material recovery). A secondary objective was to test a combination of dynamic energy system modelling and LCA by combining the concept of complex marginal electricity production in a static, environmental systems analysis. Furthermore, we wanted to increase the methodological knowledge about how waste can be environmentally compared to other fuels in district-heat production. The results indicate that combustion of biofuel in a CHP is environmentally favourable and robust with respect to the avoided type of electricity and waste management. Waste incineration is often (but not always) the preferable choice when incineration substitutes landfill disposal of waste. It is however, never the best choice (and often the worst) when incineration substitutes recycling. A natural gas fired CHP is an alternative of interest if marginal electricity has a high fossil content. However, if the marginal electricity is mainly based on non-fossil sources, natural gas is in general worse than biofuels

  11. Radioactivity of uranium production cycle facilities in the Czech Republic compared to the natural environment

    International Nuclear Information System (INIS)

    Matolin, M.

    2002-01-01

    Forty-five years (1946-1990) of intensive uranium exploration and exploitation in the Czech Republic led to mining at 64 uranium deposits. These mining and milling activities left numerous accumulations of waste rock material in the landscape. The radioactivity of these man-made accumulations was measured and compared to the natural radiation environment. Waste rock dumps at the uranium deposits Pribram, Rozna, Jachymov, Straz-Hamr and deposits in the Zelezne Hory area show surface gamma dose rates mostly in the range of 200-1000 nGy/h, with a uranium concentration 10-100 ppm eU. An extremely high radioactivity of 3000-4200 nGy/h was detected at the extensive uranium processing tailings impoundments at Straz. Terrestrial gamma dose rate of regional geological units in the Czech Republic is in the range of 6-245 nGy/h. Reclamation and recultivation of dumps, control of their radioactivity and restriction of their accessibility are the major measures introduced to protect the public. (author)

  12. Diagnosing phosphorus limitations in natural terrestrial ecosystems in carbon cycle models

    Science.gov (United States)

    Sun, Yan; Peng, Shushi; Goll, Daniel S.; Ciais, Philippe; Guenet, Bertrand; Guimberteau, Matthieu; Hinsinger, Philippe; Janssens, Ivan A.; Peñuelas, Josep; Piao, Shilong; Poulter, Benjamin; Violette, Aurélie; Yang, Xiaojuan; Yin, Yi; Zeng, Hui

    2017-07-01

    Most of the Earth System Models (ESMs) project increases in net primary productivity (NPP) and terrestrial carbon (C) storage during the 21st century. Despite empirical evidence that limited availability of phosphorus (P) may limit the response of NPP to increasing atmospheric CO2, none of the ESMs used in the previous Intergovernmental Panel on Climate Change assessment accounted for P limitation. We diagnosed from ESM simulations the amount of P need to support increases in carbon uptake by natural ecosystems using two approaches: the demand derived from (1) changes in C stocks and (2) changes in NPP. The C stock-based additional P demand was estimated to range between -31 and 193 Tg P and between -89 and 262 Tg P for Representative Concentration Pathway (RCP) 2.6 and RCP8.5, respectively, with negative values indicating a P surplus. The NPP-based demand, which takes ecosystem P recycling into account, results in a significantly higher P demand of 648-1606 Tg P for RCP2.6 and 924-2110 Tg P for RCP8.5. We found that the P demand is sensitive to the turnover of P in decomposing plant material, explaining the large differences between the NPP-based demand and C stock-based demand. The discrepancy between diagnosed P demand and actual P availability (potential P deficit) depends mainly on the assumptions about availability of the different soil P forms. Overall, future P limitation strongly depends on both soil P availability and P recycling on ecosystem scale.

  13. A comparative life cycle assessment of diesel and compressed natural gas powered refuse collection vehicles in a Canadian city

    International Nuclear Information System (INIS)

    Rose, Lars; Hussain, Mohammed; Ahmed, Syed; Malek, Kourosh; Costanzo, Robert; Kjeang, Erik

    2013-01-01

    Consumers and organizations worldwide are searching for low-carbon alternatives to conventional gasoline and diesel vehicles to reduce greenhouse gas (GHG) emissions and their impact on the environment. A comprehensive technique used to estimate overall cost and environmental impact of vehicles is known as life cycle assessment (LCA). In this article, a comparative LCA of diesel and compressed natural gas (CNG) powered heavy duty refuse collection vehicles (RCVs) is conducted. The analysis utilizes real-time operational data obtained from the City of Surrey in British Columbia, Canada. The impact of the two alternative vehicles is assessed from various points in their life. No net gain in energy use is found when a diesel powered RCV is replaced by a CNG powered RCV. However, significant reductions (approximately 24% CO 2 -equivalent) in GHG and criteria air contaminant (CAC) emissions are obtained. Moreover, fuel cost estimations based on 2011 price levels and a 5-year lifetime for both RCVs reveal that considerable cost savings may be achieved by switching to CNG vehicles. Thus, CNG RCVs are not only favorable in terms of reduced climate change impact but also cost effective compared to conventional diesel RCVs, and provide a viable and realistic near-term strategy for cities and municipalities to reduce GHG emissions. - Highlights: ► Life cycle analysis is performed on two alternative refuse collection vehicle technologies. ► Real-time operational data obtained by the City of Surrey in British Columbia are utilized. ► The life cycle energy use is similar for diesel and CNG RCVs. ► A 24% reduction of GHG emissions (CO 2 -equivalent) may be realized by switching from diesel to CNG. ► CNG RCVs are estimated to be cost effective and may lead to reduced fuel costs.

  14. Cycling of organic carbon in the ocean: use of naturally occuring radiocarbon as a long and short term tracer

    International Nuclear Information System (INIS)

    Williams, P.M.; Linick, T.W.

    1975-01-01

    The natural radiocarbon activities of surface, bathypelagic and benthic marine organisms have been measured for samples collected from the north central, north eastern and central equatorial Pacific Ocean and from the Ross Sea in Antarctica. These measurements show that 1961-1962 bomb-carbon-14 has been incorporated into the bathypelagic specimens in varying amounts. Thus, pollutants introduced into surface waters of the oceans may be removed more or less rapidly from the euphotic zone into the deep water depending upon particular food chain mechanisms. These results are discussed in relation to the cycling of disolved organic carbon, the flux of particulate organic carbon through the seawater column into the sediments, and to the oxidation rates of organic matter in the deep sea. (author)

  15. On the application of the compartment theory to the modelling of the isotopic composition of nitrogen in its natural cycle

    International Nuclear Information System (INIS)

    Winkler, E.; Wetzel, K.

    1979-01-01

    The compartment theory is presented as a means for mathematical modelling of isotope geochemical processes, taking into consideration isotopic effects. It is used to formulate a global model of the isotopic composition of nitrogen in its natural cycle, which consists of three pools connected by fluxes: nitrogen in magmatites, in the atmosphere, and in sedimentary rocks. A part from the simulation of the development of pool sizes, of delta 15 N values and of fluxes as functions of time through the history of the earth, contributions could be made to the solution of geochemical problems. The results of modelling indicate that the original atmosphere contained much less nitrogen than the present one (up to 10% of the present value), and that a nitrogen flux exists from the upper crust to the magmatites (about 6 . 10 5 tons/yr). (author)

  16. Life Cycle Energy Consumption and Greenhouse Gas Emissions Analysis of Natural Gas-Based Distributed Generation Projects in China

    Directory of Open Access Journals (Sweden)

    Hansi Liu

    2017-10-01

    Full Text Available In this paper, we used the life-cycle analysis (LCA method to evaluate the energy consumption and greenhouse gas (GHG emissions of natural gas (NG distributed generation (DG projects in China. We took the China Resources Snow Breweries (CRSB NG DG project in Sichuan province of China as a base scenario and compared its life cycle energy consumption and GHG emissions performance against five further scenarios. We found the CRSB DG project (all energy input is NG can reduce GHG emissions by 22%, but increase energy consumption by 12% relative to the scenario, using coal combined with grid electricity as an energy input. The LCA also indicated that the CRSB project can save 24% of energy and reduce GHG emissions by 48% relative to the all-coal scenario. The studied NG-based DG project presents major GHG emissions reduction advantages over the traditional centralized energy system. Moreover, this reduction of energy consumption and GHG emissions can be expanded if the extra electricity from the DG project can be supplied to the public grid. The action of combining renewable energy into the NG DG system can also strengthen the dual merit of energy conservation and GHG emissions reduction. The marginal CO2 abatement cost of the studied project is about 51 USD/ton CO2 equivalent, which is relatively low. Policymakers are recommended to support NG DG technology development and application in China and globally to boost NG utilization and control GHG emissions.

  17. Predicting the ultimate potential of natural gas SOFC power cycles with CO2 capture - Part B: Applications

    Science.gov (United States)

    Campanari, Stefano; Mastropasqua, Luca; Gazzani, Matteo; Chiesa, Paolo; Romano, Matteo C.

    2016-09-01

    An important advantage of solid oxide fuel cells (SOFC) as future systems for large scale power generation is the possibility of being efficiently integrated with processes for CO2 capture. Focusing on natural gas power generation, Part A of this work assessed the performances of advanced pressurised and atmospheric plant configurations (SOFC + GT and SOFC + ST, with fuel cell integration within a gas turbine or a steam turbine cycle) without CO2 separation. This Part B paper investigates such kind of power cycles when applied to CO2 capture, proposing two ultra-high efficiency plant configurations based on advanced intermediate-temperature SOFCs with internal reforming and low temperature CO2 separation process. The power plants are simulated at the 100 MW scale with a set of realistic assumptions about FC performances, main components and auxiliaries, and show the capability of exceeding 70% LHV efficiency with high CO2 capture (above 80%) and a low specific primary energy consumption for the CO2 avoided (1.1-2.4 MJ kg-1). Detailed results are presented in terms of energy and material balances, and a sensitivity analysis of plant performance is developed vs. FC voltage and fuel utilisation to investigate possible long-term improvements. Options for further improvement of the CO2 capture efficiency are also addressed.

  18. Analysis of Combined Cycle Power Plants with Chemical Looping Reforming of Natural Gas and Pre-Combustion CO2 Capture

    Directory of Open Access Journals (Sweden)

    Shareq Mohd Nazir

    2018-01-01

    Full Text Available In this paper, a gas-fired combined cycle power plant subjected to a pre-combustion CO2 capture method has been analysed under different design conditions and different heat integration options. The power plant configuration includes the chemical looping reforming (CLR of natural gas (NG, water gas shift (WGS process, CO2 capture and compression, and a hydrogen fuelled combined cycle to produce power. The process is denoted as a CLR-CC process. One of the main parameters that affects the performance of the process is the pressure for the CLR. The process is analysed at different design pressures for the CLR, i.e., 5, 10, 15, 18, 25 and 30 bar. It is observed that the net electrical efficiency increases with an increase in the design pressure in the CLR. Secondly, the type of steam generated from the cooling of process streams also effects the net electrical efficiency of the process. Out of the five different cases including the base case presented in this study, it is observed that the net electrical efficiency of CLR-CCs can be improved to 46.5% (lower heating value of NG basis by producing high-pressure steam through heat recovery from the pre-combustion process streams and sending it to the Heat Recovery Steam Generator in the power plant.

  19. On the determination of the overall heat transmission coefficient and soil heat flux for a fog cooled, naturally ventilated greenhouse: Analysis of radiation and convection heat transfer

    International Nuclear Information System (INIS)

    Abdel-Ghany, Ahmed M.; Kozai, Toyoki

    2006-01-01

    A physical model for analyzing the radiative and convective heat transfer in a fog cooled, naturally ventilated greenhouse was developed for estimating the overall heat transmission coefficient based on the conduction, convection and thermal radiation heat transfer coefficients and for predicting the soil heat flux. The contribution of the water vapor of the inside air to the emission and absorption of thermal radiation was determined. Measurements of the outside and inside greenhouse environments to be used in the analysis were conducted around solar noon (12:19-13:00) on a hot sunny day to provide the maximum solar radiation transmission into the greenhouse. The net solar radiation flux measured at the greenhouse floor showed a reasonable agreement with the predicted value. The net fluxes were estimated around noon. The average net radiation (solar and thermal) at the soil surface was 220.0 W m -2 , the average soil heat flux was 155.0 W m -2 and the average contribution of the water vapor of the inside air to the thermal radiation was 22.0 W m -2 . The average overall heat transmission coefficient was 4.0 W m -2 C -1 and was in the range between 3.0 W m -2 C -1 and 6.0 W m -2 C -1 under the different hot summer conditions between the inside and outside of the naturally ventilated, fog cooled greenhouse

  20. Genetics, receptor binding property, and transmissibility in mammals of naturally isolated H9N2 Avian Influenza viruses.

    Directory of Open Access Journals (Sweden)

    Xuyong Li

    2014-11-01

    Full Text Available H9N2 subtype influenza viruses have been detected in different species of wild birds and domestic poultry in many countries for several decades. Because these viruses are of low pathogenicity in poultry, their eradication is not a priority for animal disease control in many countries, which has allowed them to continue to evolve and spread. Here, we characterized the genetic variation, receptor-binding specificity, replication capability, and transmission in mammals of a series of H9N2 influenza viruses that were detected in live poultry markets in southern China between 2009 and 2013. Thirty-five viruses represented 17 genotypes on the basis of genomic diversity, and one specific "internal-gene-combination" predominated among the H9N2 viruses. This gene combination was also present in the H7N9 and H10N8 viruses that have infected humans in China. All of the 35 viruses preferentially bound to the human-like receptor, although two also retained the ability to bind to the avian-like receptor. Six of nine viruses tested were transmissible in ferrets by respiratory droplet; two were highly transmissible. Some H9N2 viruses readily acquired the 627K or 701N mutation in their PB2 gene upon infection of ferrets, further enhancing their virulence and transmission in mammals. Our study indicates that the widespread dissemination of H9N2 viruses poses a threat to human health not only because of the potential of these viruses to cause an influenza pandemic, but also because they can function as "vehicles" to deliver different subtypes of influenza viruses from avian species to humans.

  1. NMR relaxation in natural soils: Fast Field Cycling and T1-T2 Determination by IR-MEMS

    Science.gov (United States)

    Haber-Pohlmeier, S.; Pohlmeier, A.; Stapf, S.; van Dusschoten, D.

    2009-04-01

    Soils are natural porous media of highest importance for food production and sustainment of water resources. For these functions, prominent properties are their ability of water retainment and transport, which are mainly controlled by pore size distribution. The latter is related to NMR relaxation times of water molecules, of which the longitudinal relaxation time can be determined non-invasively by fast-field cycling relaxometry (FFC) and both are obtainable by inversion recovery - multi-echo- imaging (IR-MEMS) methods. The advantage of the FFC method is the determination of the field dependent dispersion of the spin-lattice relaxation rate, whereas MRI at high field is capable of yielding spatially resolved T1 and T2 times. Here we present results of T1- relaxation time distributions of water in three natural soils, obtained by the analysis of FFC data by means of the inverse Laplace transformation (CONTIN)1. Kaldenkirchen soil shows relatively broad bimodal distribution functions D(T1) which shift to higher relaxation rates with increasing relaxation field. These data are compared to spatially resolved T1- and T2 distributions, obtained by IR-MEMS. The distribution of T1 corresponds well to that obtained by FFC.

  2. Importance of bird-to-bird transmission for the establishment of West Nile Virus

    NARCIS (Netherlands)

    Hartemink, N.A.; Davis, S.A.; Reiter, P.; Hubálek, Z.; Heesterbeek, J.A.P.

    2007-01-01

    West Nile virus (WNV) is principally considered to be maintained in a mosquito–bird transmission cycle. Under experimental conditions, several other transmission routes have been observed, but the significance of these additional routes in nature is unknown. Here, we derive an expression for the

  3. Life cycle greenhouse gas emissions from U.S. liquefied natural gas exports: implications for end uses.

    Science.gov (United States)

    Abrahams, Leslie S; Samaras, Constantine; Griffin, W Michael; Matthews, H Scott

    2015-03-03

    This study analyzes how incremental U.S. liquefied natural gas (LNG) exports affect global greenhouse gas (GHG) emissions. We find that exported U.S. LNG has mean precombustion emissions of 37 g CO2-equiv/MJ when regasified in Europe and Asia. Shipping emissions of LNG exported from U.S. ports to Asian and European markets account for only 3.5-5.5% of precombustion life cycle emissions, hence shipping distance is not a major driver of GHGs. A scenario-based analysis addressing how potential end uses (electricity and industrial heating) and displacement of existing fuels (coal and Russian natural gas) affect GHG emissions shows the mean emissions for electricity generation using U.S. exported LNG were 655 g CO2-equiv/kWh (with a 90% confidence interval of 562-770), an 11% increase over U.S. natural gas electricity generation. Mean emissions from industrial heating were 104 g CO2-equiv/MJ (90% CI: 87-123). By displacing coal, LNG saves 550 g CO2-equiv per kWh of electricity and 20 g per MJ of heat. LNG saves GHGs under upstream fugitive emissions rates up to 9% and 5% for electricity and heating, respectively. GHG reductions were found if Russian pipeline natural gas was displaced for electricity and heating use regardless of GWP, as long as U.S. fugitive emission rates remain below the estimated 5-7% rate of Russian gas. However, from a country specific carbon accounting perspective, there is an imbalance in accrued social costs and benefits. Assuming a mean social cost of carbon of $49/metric ton, mean global savings from U.S. LNG displacement of coal for electricity generation are $1.50 per thousand cubic feet (Mcf) of gaseous natural gas exported as LNG ($.028/kWh). Conversely, the U.S. carbon cost of exporting the LNG is $1.80/Mcf ($.013/kWh), or $0.50-$5.50/Mcf across the range of potential discount rates. This spatial shift in embodied carbon emissions is important to consider in national interest estimates for LNG exports.

  4. Cryo-thawed embryo transfer: natural versus artificial cycle. A non-inferiority trial.(ANTARCTICA trial

    Directory of Open Access Journals (Sweden)

    Groenewoud Eva R

    2012-09-01

    Full Text Available Abstract Background Frozen thawed embryo transfer (FET is a cost- effective adjunct to IVF or IVF-ICSI treatment. In order to optimize treatment outcome, FET should be carried out during a period of optimal endometrial receptivity. To optimize implantation several methods for endometrium preparation have been proposed. In natural cycle FET (NC-FET, the endometrium develops under endogenous hormonal stimulation. The development of the dominant follicle and endometrium is monitored by ultrasound and FET is timed after triggering ovulation induction or determination of the spontaneous LH surge. In an artificial cycle FET (AC-FET estrogens and progesterone are administered to prepare the endometrium for implantation. While the currently available data show no significant difference in pregnancy rates between these methods, well designed randomized controlled trials are lacking. Moreover there is little literature on difference in cancellation rates, cost-efficiency and adverse events. Methods and design In this randomized, multi-centre, non-inferiority trial we aim to test the hypothesis that there is no significant difference in live birth rates between patients undergoing NC-FET versus AC-FET. The primary outcome will be live birth rate per embryo transfer procedure. Secondary outcomes will be ongoing and clinical pregnancy rate, cancellation rate, (serious adverse events and cost-efficiency. Based on a live birth rate of 20% and a minimal clinical important difference of 7,5% (one-sided alpha 2,5%, beta 20% a total of 1150 patients will be needed. Analyzes will be performed using both per protocol as well as intention to treat analyses. Discussion This prospective, randomized, non –inferiority trial aims to address the hypothesis that there is no significant difference in live birth rates between patients undergoing NC-FET versus patients undergoing AC-FET. Moreover it addresses cost-efficiency as well as the perceived burden of both treatments

  5. The natural chlorine cycle - Formation of the carcinogenic and greenhouse gas compound chloroform in drinking water reservoirs.

    Science.gov (United States)

    Forczek, Sándor T; Pavlík, Milan; Holík, Josef; Rederer, Luděk; Ferenčík, Martin

    2016-08-01

    Chlorine cycle in natural ecosystems involves formation of low and high molecular weight organic compounds of living organisms, soil organic matter and atmospherically deposited chloride. Chloroform (CHCl3) and adsorbable organohalogens (AOX) are part of the chlorine cycle. We attempted to characterize the dynamical changes in the levels of total organic carbon (TOC), AOX, chlorine and CHCl3 in a drinking water reservoir and in its tributaries, mainly at its spring, and attempt to relate the presence of AOX and CHCl3 with meteorological, chemical or biological factors. Water temperature and pH influence the formation and accumulation of CHCl3 and affect the conditions for biological processes, which are demonstrated by the correlation between CHCl3 and ΣAOX/Cl(-) ratio, and also by CHCl3/ΣAOX, CHCl3/AOXLMW, CHCl3/ΣTOC, CHCl3/TOCLMW and CHCl3/Cl(-) ratios in different microecosystems (e.g. old spruce forest, stagnant acidic water, humid and warm conditions with high biological activity). These processes start with the biotransformation of AOX from TOC, continue via degradation of AOX to smaller molecules and further chlorination, and finish with the formation of small chlorinated molecules, and their subsequent volatilization and mineralization. The determined concentrations of chloroform result from a dynamic equilibrium between its formation and degradation in the water; in the Hamry water reservoir, this results in a total amount of 0.1-0.7 kg chloroform and 5.2-15.4 t chloride. The formation of chloroform is affected by Cl(-) concentration, by concentrations and ratios of biogenic substrates (TOC and AOX), and by the ratios of the substrates and the product (feedback control by chloroform itself). Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Organic Rankine Cycle for Residual Heat to Power Conversion in Natural Gas Compressor Station. Part II: Plant Simulation and Optimisation Study

    Science.gov (United States)

    Chaczykowski, Maciej

    2016-06-01

    After having described the models for the organic Rankine cycle (ORC) equipment in the first part of this paper, this second part provides an example that demonstrates the performance of different ORC systems in the energy recovery application in a gas compressor station. The application shows certain specific characteristics, i.e. relatively large scale of the system, high exhaust gas temperature, low ambient temperature operation, and incorporation of an air-cooled condenser, as an effect of the localization in a compressor station plant. Screening of 17 organic fluids, mostly alkanes, was carried out and resulted in a selection of best performing fluids for each cycle configuration, among which benzene, acetone and heptane showed highest energy recovery potential in supercritical cycles, while benzene, toluene and cyclohexane in subcritical cycles. Calculation results indicate that a maximum of 10.4 MW of shaft power can be obtained from the exhaust gases of a 25 MW compressor driver by the use of benzene as a working fluid in the supercritical cycle with heat recuperation. In relation to the particular transmission system analysed in the study, it appears that the regenerative subcritical cycle with toluene as a working fluid presents the best thermodynamic characteristics, however, require some attention insofar as operational conditions are concerned.

  7. Presence of bile acids in human follicular fluid and their relation with embryo development in modified natural cycle IVF.

    Science.gov (United States)

    Nagy, R A; van Montfoort, A P A; Dikkers, A; van Echten-Arends, J; Homminga, I; Land, J A; Hoek, A; Tietge, U J F

    2015-05-01

    Are bile acids (BA) and their respective subspecies present in human follicular fluid (FF) and do they relate to embryo quality in modified natural cycle IVF (MNC-IVF)? BA concentrations are 2-fold higher in follicular fluid than in serum and ursodeoxycholic acid (UDCA) derivatives were associated with development of top quality embryos on Day 3 after fertilization. Granulosa cells are capable of synthesizing BA, but a potential correlation with oocyte and embryo quality as well as information on the presence and role of BA subspecies in follicular fluid have yet to be investigated. Between January 2001 and June 2004, follicular fluid and serum samples were collected from 303 patients treated in a single academic centre that was involved in a multicentre cohort study on the effectiveness of MNC-IVF. Material from patients who underwent a first cycle of MNC-IVF was used. Serum was not stored from all patients, and the available material comprised 156 follicular fluid and 116 matching serum samples. Total BA and BA subspecies were measured in follicular fluid and in matching serum by enzymatic fluorimetric assay and liquid chromatography-mass spectrometry, respectively. The association of BA in follicular fluid with oocyte and embryo quality parameters, such as fertilization rate and cell number, presence of multinucleated blastomeres and percentage of fragmentation on Day 3, was analysed. Embryos with eight cells on Day 3 after oocyte retrieval were more likely to originate from follicles with a higher level of UDCA derivatives than those with fewer than eight cells (P IVF were used, which resulted in 14 samples only from women with an ongoing pregnancy, therefore further prospective studies are required to confirm the association of UDCA with IVF pregnancy outcomes. The inter-cycle variability of BA levels in follicular fluid within individuals has yet to be investigated. We checked for macroscopic signs of contamination of follicular fluid by blood but the

  8. Controlling Methane Emissions in the Natural Gas Sector. A Review of Federal and State Regulatory Frameworks Governing Production, Gathering, Processing, Transmission, and Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Paranhos, Elizabeth [Energy Innovation Partners, Seoul (South Korea); Kozak, Tracy G. [Energy Innovation Partners, Seoul (South Korea); Boyd, William [Univ. of Colorado, Boulder, CO (United States); Bradbury, James [U.S. Department of Energy, Washington, DC (United States); Steinberg, D. C. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Arent, D. J. [Joint Inst. for Strategic Energy Alaysis, Washington, DC (United States)

    2015-04-23

    This report provides an overview of the regulatory frameworks governing natural gas supply chain infrastructure siting, construction, operation, and maintenance. Information was drawn from a number of sources, including published analyses, government reports, in addition to relevant statutes, court decisions and regulatory language, as needed. The scope includes all onshore facilities that contribute to methane emissions from the natural gas sector, focusing on three areas of state and federal regulations: (1) natural gas pipeline infrastructure siting and transportation service (including gathering, transmission, and distribution pipelines), (2) natural gas pipeline safety, and (3) air emissions associated with the natural gas supply chain. In addition, the report identifies the incentives under current regulatory frameworks to invest in measures to reduce leakage, as well as the barriers facing investment in infrastructure improvement to reduce leakage. Policy recommendations regarding how federal or state authorities could regulate methane emissions are not provided; rather, existing frameworks are identified and some of the options for modifying existing regulations or adopting new regulations to reduce methane leakage are discussed.

  9. Life cycle assessment of biogas production by monofermentation of energy crops and injection into the natural gas grid

    International Nuclear Information System (INIS)

    Jury, Colin; Benetto, Enrico; Koster, Daniel; Schmitt, Bianca; Welfring, Joelle

    2010-01-01

    The use of renewable energy is a possible solution to reduce the contribution to climate change of human activities. Nevertheless, there is much controversy about the non-climate related environmental impacts of renewable energy as compared to fossil energy. The aim of this study is to assess a new technology of biomethane production by monofermentation of cultivated crops. Based on the results of an attributional Life Cycle Assessment (LCA), the contribution to climate change of biomethane production and injection into the grid is 30-40% (500a time horizon) or 10-20% (100a) lower than the contribution of natural gas importation. The reduction depends mainly on the biogas yield, the amount of readily available nitrogen in the digestate and the type of agricultural practices. Nevertheless, the natural gas definitively generates far lower ecosystem quality and human health damages than the biomethane production. Farming activities have the most important contribution to the damages mainly because of land occupation and the use of fertilizer. The main improvement opportunities highlighted are: the increase of biogas yield, the choice of good agricultural practices and the cultivation of winter or summer crops exclusively. Future research should include the emission and sequestration of CO 2 from soil. The ripple effects related to the total increase of farming area and the consequences of farming activities on the food production chain should be addressed as well. To this aim, the switch to consequential LCA is a critical challenge, from both the methodological and application point of view, to support decision-making. (author)

  10. Evaluation of different end-of-life management alternatives for used natural cork stoppers through life cycle assessment.

    Science.gov (United States)

    Demertzi, Martha; Dias, Ana Cláudia; Matos, Arlindo; Arroja, Luís Manuel

    2015-12-01

    An important aspect of sustainable development is the implementation of effective and sustainable waste management strategies. The present study focuses on a Life Cycle Assessment (LCA) approach to different waste management strategies for natural cork stoppers, namely incineration at a municipal solid waste incinerator, landfilling in a sanitary landfill, and recycling. In the literature, there are no LCA studies analyzing in detail the end-of-life stage of natural cork stoppers as well as other cork products. In addition, cork is usually treated as wood at the end-of-life stage. Thus, the outcome of this study can provide an important insight into this matter. The results showed that different management alternatives, namely incineration and recycling, could be chosen depending on the impact category considered. The former alternative presented the best environmental results in the impact categories of climate change, ozone depletion and acidification, while the latter for photochemical ozone formation and mineral and fossil resource depletion. The landfilling alternative did not present the best environmental performance in any of the impact categories. However, when the biogenic carbon dioxide emission was assessed for the climate change category, the landfilling alternative was found to be the most effective since most of the biogenic carbon would be permanently stored in the cork products and not emitted into the atmosphere. A sensitivity analysis was performed and the results showed that there are various parameters that can significantly influence the results (e.g., carbon content in cork and decay rate of cork in the landfill). Thus, LCA studies should include a detailed description concerning their assumptions when the end-of-life stage is included in the boundaries since they can influence the results, and furthermore, to facilitate the comparison of different end-of-life scenarios. The present study and the obtained results could be useful for the

  11. METHODOLOGY OF ORGANIZATION OF INTEGRATED LESSONS OF NATURAL-SCIENCE CYCLE (ON THE EXAMPLE OF TEACHING SPE STUDENTS

    Directory of Open Access Journals (Sweden)

    Alsou Raufovna Kamaleeva

    2015-09-01

    Full Text Available In the process of transition of Russian organizations of secondary professional education to educational standards of the third generation educational process is reduced to formation of students’ competences. This article presents methodology of creating integrated lessons of natural-science cycle (for example, in physics and informatics. These lessons are constructed on the basis of interdisciplinary integration and focused on task solution. The main purpose is to teach students how to solve particular tasks in physics with the use of informatics, in particular on the basis of algorithmization and programming (Pascal language. Didactic conditions, which are the basis of the algorithm of designing corresponding tasks, are described in this article. Structural components of the integrated lessons created on the traditional principle are marked out. During the research we observed that realization of all stages of the corresponding lessons in practice allows the teacher to create educational process over the borders of disciplinary basis. This approach helps to form generalization of knowledge. Being one of the most optimal forms of education, an integrated lesson allows students to solve various educational and professional problems in non-standard situations and stimulates their cognitive activity and their involvement in the process of education and their responsibility for the result which promotes an intensification of educational process.

  12. Postlearning stress differentially affects memory for emotional gist and detail in naturally cycling women and women on hormonal contraceptives.

    Science.gov (United States)

    Nielsen, Shawn E; Ahmed, Imran; Cahill, Larry

    2014-08-01

    Sex differences in emotional memory have received increasing interest over the past decade. However, to date, no work has explored how a postlearning stressor might modulate the influence of sex hormone status on memory for gist and peripheral detail in an emotional versus neutral context. Here, we tested 3 predictions. First, compared with naturally cycling (NC) women in the luteal phase, women on hormonal contraception (HC) would have significantly blunted hypothalamic-pituitary-adrenal reactivity to physical stress. Second, postlearning stress would enhance detail and gist memory from an emotional story in NC women, and finally, postlearning stress would not affect emotional memory for details or gist in HC women. Healthy NC and HC women viewed a brief, narrated story containing neutral or emotionally arousing elements. Immediately after, cold pressor stress (CPS) or a control procedure was administered. One week later, participants received a surprise free recall test for story elements. NC women exhibited significantly greater cortisol increases to CPS compared with HC women. NC women who viewed the emotional story and were administered CPS recalled the most peripheral details overall and more gist from the emotional compared with the neutral story. In HC women, however, the postlearning cortisol release did not affect memory for gist or peripheral details from the emotional or neutral story in any way. Additionally, NC and HC women performed similarly on measures of attention and arousal. These findings suggest that in women, postlearning stress differentially affects memory for emotional information depending on their hormonal contraceptive status.

  13. Conceptual design study on very small long-life gas cooled fast reactor using metallic natural Uranium-Zr as fuel cycle input

    International Nuclear Information System (INIS)

    Monado, F.; Permana, S.

    2013-01-01

    Full-text: A conceptual design study of very small 350 MWth Gas-cooled Fast Reactors with Helium coolant has been performed. In this study Modified CANDLE burn-up scheme was implemented to create small and long life fast reactors with natural Uranium as fuel cycle input. Such system can utilize natural Uranium resources efficiently without the necessity of enrichment plant or reprocessing plant. The core with metallic fuel based was subdivided into 10 regions with the same volume. The fresh Natural Uranium is initially put in region-1, after one cycle of 10 years of burn-up it is shifted to region-2 and the each region-1 is filled by fresh Natural Uranium fuel. This concept is basically applied to all axial regions. The reactor discharge burn-up is 31.8 % HM. From the neutronic point of view, this design is in compliance with good performance. (author)

  14. Conceptual design study on very small long-life gas cooled fast reactor using metallic natural Uranium-Zr as fuel cycle input

    International Nuclear Information System (INIS)

    Monado, Fiber; Ariani, Menik; Su'ud, Zaki; Waris, Abdul; Basar, Khairul; Permana, Sidik; Aziz, Ferhat; Sekimoto, Hiroshi

    2014-01-01

    A conceptual design study of very small 350 MWth Gas-cooled Fast Reactors with Helium coolant has been performed. In this study Modified CANDLE burn-up scheme was implemented to create small and long life fast reactors with natural Uranium as fuel cycle input. Such system can utilize natural Uranium resources efficiently without the necessity of enrichment plant or reprocessing plant. The core with metallic fuel based was subdivided into 10 regions with the same volume. The fresh Natural Uranium is initially put in region-1, after one cycle of 10 years of burn-up it is shifted to region-2 and the each region-1 is filled by fresh Natural Uranium fuel. This concept is basically applied to all axial regions. The reactor discharge burn-up is 31.8% HM. From the neutronic point of view, this design is in compliance with good performance

  15. Can switching fuels save water? A life cycle quantification of freshwater consumption for Texas coal- and natural gas-fired electricity

    International Nuclear Information System (INIS)

    Grubert, Emily A; Beach, Fred C; Webber, Michael E

    2012-01-01

    Thermal electricity generation is a major consumer of freshwater for cooling, fuel extraction and air emissions controls, but the life cycle water impacts of different fossil fuel cycles are not well understood. Much of the existing literature relies on decades-old estimates for water intensity, particularly regarding water consumed for fuel extraction. This work uses contemporary data from specific resource basins and power plants in Texas to evaluate water intensity at three major stages of coal and natural gas fuel cycles: fuel extraction, power plant cooling and power plant emissions controls. In particular, the water intensity of fuel extraction is quantified for Texas lignite, conventional natural gas and 11 unconventional natural gas basins in Texas, including major second-order impacts associated with multi-stage hydraulic fracturing. Despite the rise of this water-intensive natural gas extraction method, natural gas extraction appears to consume less freshwater than coal per unit of energy extracted in Texas because of the high water intensity of Texas lignite extraction. This work uses new resource basin and power plant level water intensity data to estimate the potential effects of coal to natural gas fuel switching in Texas’ power sector, a shift under consideration due to potential environmental benefits and very low natural gas prices. Replacing Texas’ coal-fired power plants with natural gas combined cycle plants (NGCCs) would reduce annual freshwater consumption in the state by an estimated 53 billion gallons per year, or 60% of Texas coal power’s water footprint, largely due to the higher efficiency of NGCCs. (letter)

  16. Natural transmission of dengue virus serotype 3 by Aedes albopictus (Skuse) during an outbreak in Havelock Island: Entomological characteristics.

    Science.gov (United States)

    Sivan, Arun; Shriram, A N; Sugunan, A P; Anwesh, Maile; Muruganandam, N; Kartik, C; Vijayachari, P

    2016-04-01

    From May to June 2014, an outbreak of dengue virus (DENV) illness occurred in the Havelock Island, South Andaman. Entomological investigations were undertaken during the peak of the outbreak, from 26th May-4th June, to identify the primary vector(s) involved in the transmission so that appropriate public health measures could be implemented. Adult mosquitoes were collected by BG-Sentinel traps in houses and neighborhoods of clinically ill patients. Water holding containers were inspected for the presence of mosquito larvae and pupae. Adult mosquitoes were analyzed by RT-PCR for the presence of nucleic acids of DENV and CHIKV. A total of 498 mosquitoes were collected and processed in 27 pools. The species composition comprised of 58.3% Aedes albopictus, 7.5% Aedes aegypti and 4.2% Aedes edwardsi and 3.1% constituted others. Two A. albopictus pools were found to be positive for DENV RNA. Sequencing of the RT PCR 511 base pair amplicon positive samples showed homology with DENV-3, suggesting that serotype-3 was responsible for the outbreak and A. albopictus was the primary vector responsible. This was supported by high container (10.1%), premise (25.4%) and Breteau (27.9) indices, with miscellaneous receptacles (2.4%), tree holes (1.2%) and discarded tires (1.2%) registering relatively higher container indices. This is the first report of detection of DENV in A. albopictus from Andaman and Nicobar Islands. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Nature of macroeconomic equilibrium and driving force of economic cycles in the light of difference between money and exergy forms in cost estimations

    Energy Technology Data Exchange (ETDEWEB)

    Bandura, A.V. [National Politechnical Univ., Kiev (Ukraine); Brodianskii, V.M. [Moscow Power Engineering Inst. Technical Univ. (Russian Federation)

    1996-11-01

    The main problem of exergy application directly in economic analysis is to find valid correlation between money-based cost and exergy based one (including exergy expenses of labour) and to define exergy cost as an economic category among the existing traditional economic ones. The present report is aimed to search the way for this macroeconomic problems` solution. It is demonstrated that exergy-based cost can be recalculated in a monetary form using a coefficient, defined as a ratio between money supply and the total exergy of all natural resources involved in production process, i.e. as a ratio between monetary and exergy bases. The difference between `natural` and current prices (P) can be used directly both for general quantitative characteristics of an economic cycles driving force and for control of market relationship imperfection. It is shown that for the period of time with the positive P, that is, current price is lower than a `natural` one, the recoveries in business cycles are observed. For the period of time with the negative P, that is, current price is higher than a natural one, economic recessions are observed. The moment of time when P = 0 corresponds to the turning point of a business cycle. In such a way the possibility to predict the turning points of business cycles is demonstrated. 14 refs, 2 figs, 2 tabs

  18. Embryo quality and impact of specific embryo characteristics on ongoing implantation in unselected embryos derived from modified natural cycle in vitro fertilization

    NARCIS (Netherlands)

    Pelinck, Marie-Jose; Hoek, Annemieke; Simons, Arnold H. M.; Heineman, Maas Jan; van Echten-Arends, Janny; Arts, Eus G. J. M.

    Objective: To study the implantation potential of unselected embryos derived from modified natural cycle IVF according to their morphological characteristics. Design: Cohort study. Setting: Academic department of reproductive medicine. Patient(S): A series of 449 single embryo transfers derived from

  19. Transmission patterns of smallpox: systematic review of natural outbreaks in Europe and North America since World War II

    Directory of Open Access Journals (Sweden)

    Boer Rob

    2006-05-01

    Full Text Available Abstract Background Because smallpox (variola major may be used as a biological weapon, we reviewed outbreaks in post-World War II Europe and North America in order to understand smallpox transmission patterns. Methods A systematic review was used to identify papers from the National Library of Medicine, Embase, Biosis, Cochrane Library, Defense Technical Information Center, WorldCat, and reference lists of included publications. Two authors reviewed selected papers for smallpox outbreaks. Results 51 relevant outbreaks were identified from 1,389 publications. The median for the effective first generation reproduction rate (initial R was 2 (range 0–38. The majority outbreaks were small (less than 5 cases and contained within one generation. Outbreaks with few hospitalized patients had low initial R values (median of 1 and were prolonged if not initially recognized (median of 3 generations; outbreaks with mostly hospitalized patients had higher initial R values (median 12 and were shorter (median of 3 generations. Index cases with an atypical presentation of smallpox were less likely to have been diagnosed with smallpox; outbreaks in which the index case was not correctly diagnosed were larger (median of 27.5 cases and longer (median of 3 generations compared to outbreaks in which the index case was correctly diagnosed (median of 3 cases and 1 generation. Conclusion Patterns of spread during Smallpox outbreaks varied with circumstances, but early detection and implementation of control measures is a most important influence on the magnitude of outbreaks. The majority of outbreaks studied in Europe and North America were controlled within a few generations if detected early.

  20. Optimal design of a gas transmission network: A case study of the Turkish natural gas pipeline network system

    Science.gov (United States)

    Gunes, Ersin Fatih

    Turkey is located between Europe, which has increasing demand for natural gas and the geographies of Middle East, Asia and Russia, which have rich and strong natural gas supply. Because of the geographical location, Turkey has strategic importance according to energy sources. To supply this demand, a pipeline network configuration with the optimal and efficient lengths, pressures, diameters and number of compressor stations is extremely needed. Because, Turkey has a currently working and constructed network topology, obtaining an optimal configuration of the pipelines, including an optimal number of compressor stations with optimal locations, is the focus of this study. Identifying a network design with lowest costs is important because of the high maintenance and set-up costs. The quantity of compressor stations, the pipeline segments' lengths, the diameter sizes and pressures at compressor stations, are considered to be decision variables in this study. Two existing optimization models were selected and applied to the case study of Turkey. Because of the fixed cost of investment, both models are formulated as mixed integer nonlinear programs, which require branch and bound combined with the nonlinear programming solution methods. The differences between these two models are related to some factors that can affect the network system of natural gas such as wall thickness, material balance compressor isentropic head and amount of gas to be delivered. The results obtained by these two techniques are compared with each other and with the current system. Major differences between results are costs, pressures and flow rates. These solution techniques are able to find a solution with minimum cost for each model both of which are less than the current cost of the system while satisfying all the constraints on diameter, length, flow rate and pressure. These results give the big picture of an ideal configuration for the future state network for the country of Turkey.

  1. Optical characterization of the oceanic unicellular cyanobacterium Synechococcus grown under a day-night cycle in natural irradiance

    Science.gov (United States)

    Stramski, Dariusz; Shalapyonok, Alexi; Reynolds, Rick A.

    1995-01-01

    The optical properties of the ocenanic cyanobacterium Synechococcus (clone WH8103) were examined in a nutrient-replete laboratory culture grown under a day-night cycle in natural irradiance. Measurements of the spectral absorption and beam attenuation coefficients, the size distribution of cells in suspension, and microscopic analysis of samples were made at intervals of 2-4 hours for 2 days. These measurements were used to calculate the optical properties at the level of a single 'mean' cell representative of the acutal population, specifically, the optical cross sections for spectral absorption bar-(sigma(sub a)), scattering bar-sigma(sub b))(lambda), and attentuation bar-(sigma(sub c))(lambda). In addition, concurrent determinations of chlorophyll a and particulate organic carbon allowed calculation of the Chl a- and C-specific optical coefficients. The refractive index of cells was derived from the observed data using a theory of light absorption and scattering by homogeneous spheres. Low irradiance because of cloudy skies resulted in slow division rates of cells in the culture. The percentage of dividing cells was unusually high (greater than 30%) throughout the experiment. The optical cross sections varied greatly over a day-night cycle, with a minimum near dawn or midmorning and maximum near dusk. During daylight hours, bar-(sigma(sub b)) and bar-(sigma(sub c)) can increase more than twofold and bar-(sigma(sub a) by as much as 45%. The real part of the refractive index n increaed during the day; changes in n had equal or greater effect than the varying size distribution on changes in bar-(sigma(sub c)) and bar-(sigma(sub b)). The contribution of changes in n to the increase of bar-(sigma(sub c))(660) during daylight hours was 65.7% and 45.1% on day 1 and 2, respectively. During the dark period, when bar-(sigma(sub c))(660) decreased by a factor of 2.9, the effect of decreasing n was dominant (86.3%). With the exception of a few hours during the second light

  2. Application of optimal design methodologies in retrofitting natural gas combined cycle power plants with CO_2 capture

    International Nuclear Information System (INIS)

    Pan, Ming; Aziz, Farah; Li, Baohong; Perry, Simon; Zhang, Nan; Bulatov, Igor; Smith, Robin

    2016-01-01

    Highlights: • A new approach is proposed for retrofitting NGCC power plants with CO2 capture. • HTI techniques are developed for improving heat recovery in NGCC power plants. • EGR techniques are developed to increase the process overall energy efficiency. • The proposed methods are efficient for practical application. - Abstract: Around 21% of the world’s power production is based on natural gas. Energy production is considered to be the significant sources of carbon dioxide (CO_2) emissions. This has a significant effect on the global warming. Improving power plant efficiency and adding a CO_2 capture unit into power plants, have been suggested to be a promising countermeasure against global warming. This paper presents a new insight to the application of energy efficient technologies in retrofitting natural gas combined cycle (NGCC) power plants with CO_2 capture. High fidelity models of a 420 MW NGCC power plant and a CO_2 capture plant with CO_2 compression train have been built and integrated for 90% capture level. These models have been then validated by comparisons with practical operating data and literature results. The novelty of the paper is to propose optimal retrofitting strategies to minimize the efficiency penalty caused by integrating carbon capture units into the power plant, including (1) implementing heat transfer intensification techniques to increase energy saving in the heat recovery steam generator (HRSG) of the power plant; (2) extracting suitable steam from the HRSG to supply the heat required by the capture process, thus on external heat is purchased; (3) employing exhaust gas recirculation (EGR) to increase the overall energy efficiency of the integrated process, which can benefit both power plant (e.g. increasing power plant efficiency) and capture process (e.g. reducing heat demands). Compared with the base case without using any integrating and retrofitting strategies, the optimal solution based on the proposed approaches

  3. Arctigenin, a natural lignan compound, induces G0/G1 cell cycle arrest and apoptosis in human glioma cells.

    Science.gov (United States)

    Maimaitili, Aisha; Shu, Zunhua; Cheng, Xiaojiang; Kaheerman, Kadeer; Sikandeer, Alifu; Li, Weimin

    2017-02-01

    The aim of the current study was to investigate the anticancer potential of arctigenin, a natural lignan compound, in malignant gliomas. The U87MG and T98G human glioma cell lines were treated with various concentrations of arctigenin for 48 h and the effects of arctigenin on the aggressive phenotypes of glioma cells were assessed. The results demonstrated that arctigenin dose-dependently inhibited the growth of U87MG and T98G cells, as determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and bromodeoxyuridine incorporation assays. Arctigenin exposure also induced a 60-75% reduction in colony formation compared with vehicle-treated control cells. However, arctigenin was not observed to affect the invasiveness of glioma cells. Arctigenin significantly increased the proportion of cells in the G 0 /G 1 phase and reduced the number of cells in the S phase, as compared with the control group (Parctigenin increased the expression levels of p21, retinoblastoma and p53 proteins, and significantly decreased the expression levels of cyclin D1 and cyclin-dependent kinase 4 proteins. Additionally, arctigenin was able to induce apoptosis in glioma cells, coupled with increased expression levels of cleaved caspase-3 and the pro-apoptotic BCL2-associated X protein. Furthermore, arctigenin-induced apoptosis was significantly suppressed by the pretreatment of cells with Z-DEVD-FMK, a caspase-3 inhibitor. In conclusion, the results suggest that arctigenin is able to inhibit cell proliferation and may induce apoptosis and cell cycle arrest at the G 0 /G 1 phase in glioma cells. These results warrant further investigation of the anticancer effects of arctigenin in animal models of gliomas.

  4. Natural history of Ctenus medius Keyserling, 1891 (Aranae, Ctenidae II: life cycle and aspects of reproductive behavior under laboratory conditions

    Directory of Open Access Journals (Sweden)

    E. FOLLY-RAMOS

    Full Text Available Ctenus medius Keyserling, 1891 is a wandering spider common in the Brazilian Atlantic Forest. It has been the subject of few studies. Thus, this work aims to elucidate aspects of its natural history, such as the life cycle and reproductive behavior of this species, through laboratory and field observations. Two females with egg sacs were observed in the laboratory and one was observed in field (Barra Mansa, 22º32'S and 44º10'W until the emergence of the spiderlings. For observation of the immature stage development, a portion of the spiderlings from the same hatch were taken to the laboratory and watched until sexual maturity. In the field, the period between the oviposition and the emergence of spiderlings was of 36 days. The female selects a site for egg sac deposition and stays there until the spiderlings emerge. Seven days after the emergence, the female abandoned the site where the egg sac was made, concomitant to the spiderlings dispersion from observation's place and until the moment that the spiderlings started to eat. For the spiderlings kept under laboratory conditions, cannibalism was not observed in the first instars (1-4th when sufficient food was offered. Sexual maturity happened in the 14th or 15th instars, with an average of 309.2 to 344.5 days until the last/sexual molt, respectively. Until the date of sexual maturity, there was a mortality rate of 85%. This species is very fragile in captivity. This hampered deductions concerning longevity. Both females and males collected in the field were induced to mate in the laboratory. Courtship movements of males were registered, but the females did not permit the mating. These data may assist in initial biological studies of Ctenus genus and offer comparative parameters for studies of other related species.

  5. Natural history of Ctenus medius Keyserling, 1891 (Aranae, Ctenidae II: life cycle and aspects of reproductive behavior under laboratory conditions

    Directory of Open Access Journals (Sweden)

    FOLLY-RAMOS E.

    2002-01-01

    Full Text Available Ctenus medius Keyserling, 1891 is a wandering spider common in the Brazilian Atlantic Forest. It has been the subject of few studies. Thus, this work aims to elucidate aspects of its natural history, such as the life cycle and reproductive behavior of this species, through laboratory and field observations. Two females with egg sacs were observed in the laboratory and one was observed in field (Barra Mansa, 22º32'S and 44º10'W until the emergence of the spiderlings. For observation of the immature stage development, a portion of the spiderlings from the same hatch were taken to the laboratory and watched until sexual maturity. In the field, the period between the oviposition and the emergence of spiderlings was of 36 days. The female selects a site for egg sac deposition and stays there until the spiderlings emerge. Seven days after the emergence, the female abandoned the site where the egg sac was made, concomitant to the spiderlings dispersion from observation's place and until the moment that the spiderlings started to eat. For the spiderlings kept under laboratory conditions, cannibalism was not observed in the first instars (1-4th when sufficient food was offered. Sexual maturity happened in the 14th or 15th instars, with an average of 309.2 to 344.5 days until the last/sexual molt, respectively. Until the date of sexual maturity, there was a mortality rate of 85%. This species is very fragile in captivity. This hampered deductions concerning longevity. Both females and males collected in the field were induced to mate in the laboratory. Courtship movements of males were registered, but the females did not permit the mating. These data may assist in initial biological studies of Ctenus genus and offer comparative parameters for studies of other related species.

  6. Natural transovarial transmission of dengue virus 4 in Aedes aegypti from Cuiabá, State of Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    Lucinéia Claudia de Toni Aquino da Cruz

    2015-02-01

    Full Text Available INTRODUCTION: Dengue is the most prevalent arboviral disease in tropical areas. In Mato Grosso, outbreaks are reported every year, but studies on dengue in this state are scarce. METHODS: Natural transovarial infection of Aedes aegypti by a flavivirus was investigated in the Jardim Industriário neighborhood of Cuiabá, Mato Grosso. Eggs were collected with ovitraps during the dry, intermediate, and rainy seasons of 2012. After the eggs hatched and the larvae developed to adulthood, mosquitoes (n = 758 were identified and allocated to pools of 1-10 specimens according to the collection location, sex, and climatic period. After RNA extraction, multiplex semi-nested RT-PCR was performed to detect the four dengue virus (DENV serotypes, yellow fever virus, West Nile virus and Saint Louis encephalitis virus. RESULTS: DENV-4 was the only flavivirus detected, and it was found in 8/50 pools (16.0%. Three of the positive pools contained females, and five contained males. Their nucleotide sequences presented 96-100% similarity with DENV-4 genotype II strains from Manaus, Amazonas. The minimum infection rate was 10.5 per 1000 specimens, and the maximum likelihood estimator of the infection rate was 11.6 (95% confidence interval: 4.8; 23.3. CONCLUSIONS: This study provides the first evidence of natural transovarial infection by DENV-4 in Ae. Aegypti in Mato Grosso, suggesting that this type of infection might serve as a mechanism of virus maintenance during interepidemic periods in Cuiabá, a city where dengue epidemics are reported every year. These results emphasize the need for efficient vector population control measures to prevent arbovirus outbreaks in the state.

  7. Optimization of advenced liquid natural gas-fuelled combined cycle machinery systems for a high-speed ferry

    DEFF Research Database (Denmark)

    Tveitaskog, Kari Anne; Haglind, Fredrik

    2012-01-01

    . Furthermore, practical and operational aspects of using these three machinery systems for a high-speed ferry are discussed. Two scenarios are evaluated. The first scenario evaluates the combined cycles with a given power requirement, optimizing the combined cycle while operating the gas turbine at part load...

  8. Maryland power plants and the environment. A review of the impacts of power plants and transmission lines on Maryland's natural resources

    International Nuclear Information System (INIS)

    1999-01-01

    The Maryland Department of Natural Resources (DNR) Power Plant Research Program (PPRP) is required by Maryland law to review and evaluate the potential impacts to Maryland's environment from the construction and operation of electric power generating and transmission systems. PPRP summarizes these evaluations every other year in a document known as the Cumulative Environmental Impact Report (CEIR). This volume represents the tenth edition (CEIR-10), and it summarizes the current state of knowledge which PPRP has gained from more than 25 years of continuous monitoring of power plant impacts in Maryland. PPRP conducts a range of research and monitoring projects on the topics addressed in this CEIR and many other issues as well. In fact, PPRP publishes a Bibliography every year that lists the general and site-specific power plant related reports that PPRP has produced since the early 1970s

  9. Life cycle air emissions impacts and ownership costs of light-duty vehicles using natural gas as a primary energy source.

    Science.gov (United States)

    Luk, Jason M; Saville, Bradley A; MacLean, Heather L

    2015-04-21

    This paper aims to comprehensively distinguish among the merits of different vehicles using a common primary energy source. In this study, we consider compressed natural gas (CNG) use directly in conventional vehicles (CV) and hybrid electric vehicles (HEV), and natural gas-derived electricity (NG-e) use in plug-in battery electric vehicles (BEV). This study evaluates the incremental life cycle air emissions (climate change and human health) impacts and life cycle ownership costs of non-plug-in (CV and HEV) and plug-in light-duty vehicles. Replacing a gasoline CV with a CNG CV, or a CNG CV with a CNG HEV, can provide life cycle air emissions impact benefits without increasing ownership costs; however, the NG-e BEV will likely increase costs (90% confidence interval: $1000 to $31 000 incremental cost per vehicle lifetime). Furthermore, eliminating HEV tailpipe emissions via plug-in vehicles has an insignificant incremental benefit, due to high uncertainties, with emissions cost benefits between -$1000 and $2000. Vehicle criteria air contaminants are a relatively minor contributor to life cycle air emissions impacts because of strict vehicle emissions standards. Therefore, policies should focus on adoption of plug-in vehicles in nonattainment regions, because CNG vehicles are likely more cost-effective at providing overall life cycle air emissions impact benefits.

  10. Humans Transforming the Water Cycle: Implications for Society and Nature over a Multi-Century Timeframe through Synthesis Studies (Invited)

    Science.gov (United States)

    Vorosmarty, C. J.; Hermans, C. M.; Green, M.; Pastore, C. L.; Arrigo, J. S.; Parolari, A.

    2010-12-01

    Fresh water is widely regarded as a fundamental, and arguably the most essential, natural resource, supporting a broad array of societal benefits that include basic provisioning services for domestic water supply, the food and energy sectors, commerce, cultural, recreational, and aesthetic values. Water is also critical to the maintenance of ecosystem services and biodiversity. Recent analysis of the global water system using a high resolution geospatial approach demonstrates that a wide array of stressors combine to produce a pattern of worldwide threat to much of the fresh water resource base that sustains human water supply and that is essential to maintaining aquatic biodiversity. A pervasive, globally-significant pattern of management is evident in the contemporary setting, through which impairment accumulates as a function of wealth, but is then remedied by costly technological investments. This strategy of treating symptoms while leaving unabated the underlying causes is practiced widely across rich countries but strands poor nations and much of the world's aquatic biodiversity in a high level of vulnerability. Through research organized under the Northeast Regional Consortium for Hydrologic Synthesis, we are studying a region of the U.S. that serves as an ideal example of the major changes that have taken place with respect to the hydrologic cycle over national and indeed global scales. Using a combination of biogeophysical, social science, and historical scholarship techniques --including the development of a prototype Digital History-- we address an interdisciplinary synthesis goal, that is: To quantify the widespread alteration of hydrologic systems over local-to-regional domains focusing on the Northeast Corridor of the United States over a 500-yr period (1600 to 2100)—The 500-Year Challenge. Pursuing this centuries-scale analysis allows us to gain insight into how water management strategies first became established and ultimately entrenched in the

  11. Use of the available energy in the re-gasification process of liquefied natural gas by coupling combined heat and power cycles

    Energy Technology Data Exchange (ETDEWEB)

    Sgarbi, P.V.; Schmeda Lopez, D.R.; Indrusiak, M.L.S.; Schneider, P. Smith [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Dept. of Mechanical Engineering], Emails: guetuso@gmail.com, diego.schmeda@ufrgs.br, sperbindrusiak@via-rs.net, pss@mecanica.ufrgs.br

    2009-07-01

    This work evaluates the possibilities of taking advantage of the heat transferred in the re-gasification process of liquid natural gas (LNG). It is proposed the coupling of a Brayton-Rankine combined heat and power plant (CHP) to a LNG re-gasification plant in order to use the heat involved in this process as cold source for the CHP plant. For comparison, the same CHP is simulated exchanging heat with a reference environment. An analysis is performed assuming that the amount of natural gas fed to the Brayton sub-cycle combustion chamber is equal for both cases. The CHP coupled to the re-gasification plant present a net power generation of 22.7 MW and the efficiency is 45.5%. It represents a gain of 2.98 MW in the power generation and 15% in the cycle efficiency, when compared to the reference cycle. The exergetic efficiency with this proposal is 49.3%, which is 9% higher than the reference cycle. (author)

  12. Optimal Siting and Sizing of Multiple DG Units for the Enhancement of Voltage Profile and Loss Minimization in Transmission Systems Using Nature Inspired Algorithms

    Directory of Open Access Journals (Sweden)

    Ambika Ramamoorthy

    2016-01-01

    Full Text Available Power grid becomes smarter nowadays along with technological development. The benefits of smart grid can be enhanced through the integration of renewable energy sources. In this paper, several studies have been made to reconfigure a conventional network into a smart grid. Amongst all the renewable sources, solar power takes the prominent position due to its availability in abundance. Proposed methodology presented in this paper is aimed at minimizing network power losses and at improving the voltage stability within the frame work of system operation and security constraints in a transmission system. Locations and capacities of DGs have a significant impact on the system losses in a transmission system. In this paper, combined nature inspired algorithms are presented for optimal location and sizing of DGs. This paper proposes a two-step optimization technique in order to integrate DG. In a first step, the best size of DG is determined through PSO metaheuristics and the results obtained through PSO is tested for reverse power flow by negative load approach to find possible bus locations. Then, optimal location is found by Loss Sensitivity Factor (LSF and weak (WK bus methods and the results are compared. In a second step, optimal sizing of DGs is determined by PSO, GSA, and hybrid PSOGSA algorithms. Apart from optimal sizing and siting of DGs, different scenarios with number of DGs (3, 4, and 5 and PQ capacities of DGs (P alone, Q alone, and  P and Q both are also analyzed and the results are analyzed in this paper. A detailed performance analysis is carried out on IEEE 30-bus system to demonstrate the effectiveness of the proposed methodology.

  13. Optimal Siting and Sizing of Multiple DG Units for the Enhancement of Voltage Profile and Loss Minimization in Transmission Systems Using Nature Inspired Algorithms.

    Science.gov (United States)

    Ramamoorthy, Ambika; Ramachandran, Rajeswari

    2016-01-01

    Power grid becomes smarter nowadays along with technological development. The benefits of smart grid can be enhanced through the integration of renewable energy sources. In this paper, several studies have been made to reconfigure a conventional network into a smart grid. Amongst all the renewable sources, solar power takes the prominent position due to its availability in abundance. Proposed methodology presented in this paper is aimed at minimizing network power losses and at improving the voltage stability within the frame work of system operation and security constraints in a transmission system. Locations and capacities of DGs have a significant impact on the system losses in a transmission system. In this paper, combined nature inspired algorithms are presented for optimal location and sizing of DGs. This paper proposes a two-step optimization technique in order to integrate DG. In a first step, the best size of DG is determined through PSO metaheuristics and the results obtained through PSO is tested for reverse power flow by negative load approach to find possible bus locations. Then, optimal location is found by Loss Sensitivity Factor (LSF) and weak (WK) bus methods and the results are compared. In a second step, optimal sizing of DGs is determined by PSO, GSA, and hybrid PSOGSA algorithms. Apart from optimal sizing and siting of DGs, different scenarios with number of DGs (3, 4, and 5) and PQ capacities of DGs (P alone, Q alone, and P and Q both) are also analyzed and the results are analyzed in this paper. A detailed performance analysis is carried out on IEEE 30-bus system to demonstrate the effectiveness of the proposed methodology.

  14. Post-learning stress differentially affects memory for emotional gist and detail in naturally cycling women and women on hormonal contraceptives

    OpenAIRE

    Nielsen, Shawn E.; Ahmed, Imran; Cahill, Larry

    2014-01-01

    Sex differences in emotional memory have received increasing interest over the past decade. However, to date, no work has explored how a post-learning stressor might modulate the influence of sex hormone status on memory for gist and peripheral detail in an emotional versus neutral context. Here, we tested three predictions. First, compared to naturally cycling women (NC women) in the luteal phase, women on hormonal contraception (HC women) would have significantly blunted HPA reactivity to p...

  15. Analyzing the Performance of a Dual Loop Organic Rankine Cycle System for Waste Heat Recovery of a Heavy-Duty Compressed Natural Gas Engine

    Directory of Open Access Journals (Sweden)

    Baofeng Yao

    2014-11-01

    Full Text Available A dual loop organic Rankine cycle (DORC system is designed to recover waste heat from a heavy-duty compressed natural gas engine (CNGE, and the performance of the DORC–CNGE combined system is simulated and discussed. The DORC system includes high-temperature (HT and low-temperature (LT cycles. The HT cycle recovers energy from the exhaust gas emitted by the engine, whereas the LT cycle recovers energy from intake air, engine coolant, and the HT cycle working fluid in the preheater. The mathematical model of the system is established based on the first and second laws of thermodynamics. The characteristics of waste heat energy from the CNGE are calculated according to engine test data under various operating conditions. Moreover, the performance of the DORC–CNGE combined system is simulated and analyzed using R245fa as the working fluid. Results show that the maximum net power output and the maximum thermal efficiency of the DORC system are 29.37 kW and 10.81%, respectively, under the rated power output condition of the engine. Compared with the original CNG engine, the maximum power output increase ratio and the maximum brake specific fuel consumption improvement ratio are 33.73% and 25%, respectively, in the DORC–CNGE combined system.

  16. Energy efficiency - cogeneration - marketing - natural gas market: a complete cycle; Eficiencia energetica - cogeracao - marketing - mercado de gas natural: um ciclo completo

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, J. Ricardo Uchoa C. [PETROBRAS - Gas e Energia, Rio de Janeiro, RJ (Brazil). Unidade de Negocios de Gas Natural; Aragao, Raimundo [International Institute for Energy Conservation - IIEC, Rio de Janeiro, RJ (Brazil); Arruda, Rodrigo

    2004-07-01

    This paper shows the current level of some technologies which are applied in Combined Heat Power - CHP, having natural gas as fuel, and the future perspectives for its technological advances. The work introduces the economic feasibility of these technologies having as reference the present prices of electricity and natural gas in Brazilian Market. This report also informs the influence of specific parameters in Combined Heat Power - CHP projects net present value. Finally the paper shows the main barrels for Combined Heat Power - CHP dissemination in Brazil and indicates some recommendations on how to eliminate and/or attenuate them. (author)

  17. natural

    Directory of Open Access Journals (Sweden)

    Elías Gómez Macías

    2006-01-01

    Full Text Available Partiendo de óxido de magnesio comercial se preparó una suspensión acuosa, la cual se secó y calcinó para conferirle estabilidad térmica. El material, tanto fresco como usado, se caracterizó mediante DRX, área superficial BET y SEM-EPMA. El catalizador mostró una matriz de MgO tipo periclasa con CaO en la superficie. Las pruebas de actividad catalítica se efectuaron en lecho fijo empacado con partículas obtenidas mediante prensado, trituración y clasificación del material. El flujo de reactivos consistió en mezclas gas natural-aire por debajo del límite inferior de inflamabilidad. Para diferentes flujos y temperaturas de entrada de la mezcla reactiva, se midieron las concentraciones de CH4, CO2 y CO en los gases de combustión con un analizador de gases tipo infrarrojo no dispersivo (NDIR. Para alcanzar conversión total de metano se requirió aumentar la temperatura de entrada al lecho a medida que se incrementó el flujo de gases reaccionantes. Los resultados obtenidos permiten desarrollar un sistema de combustión catalítica de bajo costo con un material térmicamente estable, que promueva la alta eficiencia en la combustión de gas natural y elimine los problemas de estabilidad, seguridad y de impacto ambiental negativo inherentes a los procesos de combustión térmica convencional.

  18. GLOBALIZATION VERSUS SEGREGATION - BUSINESS CYCLES SYNCHRONIZATION IN EUROPE

    Directory of Open Access Journals (Sweden)

    Sebastian Florian Enea

    2012-12-01

    Full Text Available Globalization and business cycles are equally elusive economic phenomena; hence they represent a continuous research possibility and a source of possible inquiries due to their complex nature. The aim of the paper is to explain the synchronization of business cycles using the relationship between the growth rate of the GDP and FDI, considered as percentage of the GDP. The results show that there is no unique European business cycle, but two cores between which countries migrate and stress out the importance of the FDI channel in business cycle transmission. The future research directions will employ fuzzy cluster techniques, used on a larger sample.

  19. The nonadaptive nature of the H1N1 2009 Swine Flu pandemic contrasts with the adaptive facilitation of transmission to a new host

    Directory of Open Access Journals (Sweden)

    Abdussamad Juwaeriah

    2011-01-01

    Full Text Available Abstract Background The emergence of the 2009 H1N1 Influenza pandemic followed a multiple reassortment event from viruses originally circulating in swines and humans, but the adaptive nature of this emergence is poorly understood. Results Here we base our analysis on 1180 complete genomes of H1N1 viruses sampled in North America between 2000 and 2010 in swine and human hosts. We show that while transmission to a human host might require an adaptive phase in the HA and NA antigens, the emergence of the 2009 pandemic was essentially nonadaptive. A more detailed analysis of the NA protein shows that the 2009 pandemic sequence is characterized by novel epitopes and by a particular substitution in loop 150, which is responsible for a nonadaptive structural change tightly associated with the emergence of the pandemic. Conclusions Because this substitution was not present in the 1918 H1N1 pandemic virus, we posit that the emergence of pandemics is due to epistatic interactions between sites distributed over different segments. Altogether, our results are consistent with population dynamics models that highlight the epistatic and nonadaptive rise of novel epitopes in viral populations, followed by their demise when the resulting virus is too virulent.

  20. Cost characteristics of transmission

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    FERC regulation of transmission is predicated, at least in part, on a belief that, in the absence of regulation, some utilities would be able to exercise monopoly power and the ability to extract monopoly profits. This monopoly power follows from the view that transmission facilities inevitably are a natural monopoly for both economic and social/regulatory reasons. In the first part of this section the authors present the argument that transmission is a natural monopoly. They then consider the impact of this on regulation and the problems that that view creates

  1. The study of capability natural uranium as fuel cycle input for long life gas cooled fast reactors with helium as coolant

    Energy Technology Data Exchange (ETDEWEB)

    Ariani, Menik, E-mail: menikariani@gmail.com; Satya, Octavianus Cakra; Monado, Fiber [Department of Physics, Faculty of Mathematics and Natural Sciences, Sriwijaya University, jl Palembang-Prabumulih km 32 Indralaya OganIlir, South of Sumatera (Indonesia); Su’ud, Zaki [Nuclear and Biophysics Research Division, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, jlGanesha 10, Bandung (Indonesia); Sekimoto, Hiroshi [CRINES, Tokyo Institute of Technology, 2-12-11N1-17 Ookayama, Meguro-Ku, Tokyo (Japan)

    2016-03-11

    The objective of the present research is to assess the feasibility design of small long-life Gas Cooled Fast Reactor with helium as coolant. GCFR included in the Generation-IV reactor systems are being developed to provide sustainable energy resources that meet future energy demand in a reliable, safe, and proliferation-resistant manner. This reactor can be operated without enrichment and reprocessing forever, once it starts. To obtain the capability of consuming natural uranium as fuel cycle input modified CANDLE burn-up scheme was adopted in this system with different core design. This study has compared the core with three designs of core reactors with the same thermal power 600 MWth. The fuel composition each design was arranged by divided core into several parts of equal volume axially i.e. 6, 8 and 10 parts related to material burn-up history. The fresh natural uranium is initially put in region 1, after one cycle of 10 years of burn-up it is shifted to region 2 and the region 1 is filled by fresh natural uranium fuel. This concept is basically applied to all regions, i.e. shifted the core of the region (i) into region (i+1) region after the end of 10 years burn-up cycle. The calculation results shows that for the burn-up strategy on “Region-8” and “Region-10” core designs, after the reactors start-up the operation furthermore they only needs natural uranium supply to the next life operation until one period of refueling (10 years).

  2. Comparative study for axial and radial shuffling scheme effect on the performance of Pb-Bi cooled fast reactors with natural uranium as fuel cycle input

    International Nuclear Information System (INIS)

    Zaki Suud; Indah Rosidah; Maryam Afifah; Ferhat Aziz; Sekimoto, H.

    2013-01-01

    Full text:Comparative study for the Design of Pb-Bi cooled fast reactors with natural uranium as fuel cycle input using special radial shuffling strategy and axial direction modified CANDLE burn-up scheme has been performed. The reactors utilizes UN-PuN as fuel, Eutectic Pb-Bi as coolant, and can be operated without refueling for 10 years in each batch. Reactor design optimization is performed to utilize natural uranium as fuel cycle input. This reactor subdivided into 6-10 regions with equal volume in radial directions. The natural uranium is initially put in region 1, and after one cycle of 10 years of burn-up it is shifted to region 2 and the region 1 is filled by fresh natural uranium fuel. This concept is basically applied to all regions. The calculation has been done by using SRAC-Citation system code and JENDL-3.2 library. The effective multiplication factor change increases monotonously during 10 years reactor operation time. There is significant power distribution change in the central part of the core during the BOC and the EOC in the radial shuffling system. It is larger than that in the case of modified CANDLE case which use axial direction burning region move. The burn-up level of fuel is slowly grows during the first 15 years but then grow faster in the rest of burn-up history. This pattern is a little bit different from the case of modified CANDLE burn-up scheme in Axial direction in which the slow growing burn-up period is relatively longer almost half of the burn-up history. (author)

  3. Hydrophobic durability characteristics of butterfly wing surface after freezing cycles towards the design of nature inspired anti-icing surfaces.

    Directory of Open Access Journals (Sweden)

    Tingkun Chen

    Full Text Available The hydrophobicity and anti-icing performance of the surfaces of some artificial hydrophobic coatings degraded after several icing and de-icing cycles. In this paper, the frost formation on the surfaces of butterfly wings from ten different species was observed, and the contact angles were measured after 0 to 6 frosting/defrosting cycles. The results show that no obvious changes in contact angle for the butterfly wing specimens were not obvious during the frosting/defrosting process. Further, the conclusion was inferred that the topography of the butterfly wing surface forms a special space structure which has a larger space inside that can accommodate more frozen droplets; this behavior prevents destruction of the structure. The findings of this study may provide a basis and new concepts for the design of novel industrially important surfaces to inhibit frost/ice growth, such as durable anti-icing coatings, which may decrease or prevent the socio-economic loss.

  4. Hydrophobic durability characteristics of butterfly wing surface after freezing cycles towards the design of nature inspired anti-icing surfaces.

    Science.gov (United States)

    Chen, Tingkun; Cong, Qian; Qi, Yingchun; Jin, Jingfu; Choy, Kwang-Leong

    2018-01-01

    The hydrophobicity and anti-icing performance of the surfaces of some artificial hydrophobic coatings degraded after several icing and de-icing cycles. In this paper, the frost formation on the surfaces of butterfly wings from ten different species was observed, and the contact angles were measured after 0 to 6 frosting/defrosting cycles. The results show that no obvious changes in contact angle for the butterfly wing specimens were not obvious during the frosting/defrosting process. Further, the conclusion was inferred that the topography of the butterfly wing surface forms a special space structure which has a larger space inside that can accommodate more frozen droplets; this behavior prevents destruction of the structure. The findings of this study may provide a basis and new concepts for the design of novel industrially important surfaces to inhibit frost/ice growth, such as durable anti-icing coatings, which may decrease or prevent the socio-economic loss.

  5. Dynamic simulation of natural convection bypass two-circuit cycle refrigerator-freezer and its application Part I: Component models

    International Nuclear Information System (INIS)

    Ding Guoliang; Zhang Chunlu; Lu Zhili

    2004-01-01

    In order to reduce the greenhouse gas emissions, efficient household refrigerator/freezers (RFs) are required. Bypass two-circuit cycle RFs with one compressor are proved to be more efficient than two-evaporator in series cycle RFs. In order to study the characteristics and improve the design of bypass two-circuit cycle RFs, a dynamic model is developed in this paper. In part I, the mathematic models of all components are presented, considering not only the accuracy of the models but also the computation stability and speed to solve the models. An efficiency model that requires a single calorimeter data point at the standard test condition is employed for compressor. A multi-zone model is employed for condenser and for evaporator, with its wall thermal capacity considered by effective metal method. The approximate integral analytic model is employed for adiabatic capillary tube, and the effective inlet enthalpy method is used to transfer the non-adiabatic capillary tube to adiabatic capillary tube. The z-transfer function model is employed for cabinet load calculation

  6. Using Dynamic Simulation to Evaluate Attemperator Operation in a Natural Gas Combined Cycle With Duct Burners in the Heat Recovery Steam Generator

    Energy Technology Data Exchange (ETDEWEB)

    Liese, Eric [National Energy Technology Laboratory,Department of Energy,Systems Engineering and Analysis Division,Morgantown, WV 26507e-mail: eric.liese@netl.doe.gov; Zitney, Stephen E. [National Energy Technology Laboratory,Department of Energy,Systems Engineering and Analysis Division,Morgantown, WV 26507e-mail: stephen.zitney@netl.doe.gov

    2017-09-26

    A generic training simulator of a natural gas combined cycle was modified to match operations at a real plant. The objective was to use the simulator to analyze cycling operations of the plant. Initial operation of the simulator revealed the potential for saturation conditions in the final high pressure superheater as the attemperator tried to control temperature at the superheater outlet during gas turbine loading and unloading. Subsequent plant operational data confirmed simulation results. Multiple simulations were performed during loading and unloading of the gas turbine to determine operational strategies that prevented saturation and increased the approach to saturation temperature. The solutions included changes to the attemperator temperature control setpoints and strategic control of the steam turbine inlet pressure control valve.

  7. Inhibin-B secretion and FSH isoform distribution may play an integral part of follicular selection in the natural menstrual cycle

    DEFF Research Database (Denmark)

    Andersen, C. Yding

    2017-01-01

    The aim of the present paper is to expand the concept on how follicular selection takes place in the follicular phase of the natural menstrual cycle. It is suggested that inhibin-B exerts a more intimate role in this process than previously understood. Inhibin-B shows a peak in the circulation...... around cycle day 7, simultaneous with selection of the dominant follicle, whereas levels of estradiol and inhibin-A only start to increase a few days later suggesting that inhibin-B is mainly responsible for downregulating pituitary FSH release. New data now demonstrate that the circulatory peak...... of inhibin-B is reflected by peak production of inhibin-B, in contrast to inhibin-A, in the selected follicle with a diameter of 10-12 mm, where concentrations are one thousand times higher than in the circulation. This high inhibin-B concentration also exerts paracrine effects, stimulating theca cell...

  8. Natural Transmutation of Actinides via the Fission Reaction in the Closed Thorium-Uranium-Plutonium Fuel Cycle

    Science.gov (United States)

    Marshalkin, V. Ye.; Povyshev, V. M.

    2017-12-01

    It is shown for a closed thorium-uranium-plutonium fuel cycle that, upon processing of one metric ton of irradiated fuel after each four-year campaign, the radioactive wastes contain 54 kg of fission products, 0.8 kg of thorium, 0.10 kg of uranium isotopes, 0.005 kg of plutonium isotopes, 0.002 kg of neptunium, and "trace" amounts of americium and curium isotopes. This qualitatively simplifies the handling of high-level wastes in nuclear power engineering.

  9. Simulation and Optimization of an Innovative Dual Mixed Component Refrigerant Cycle (DMRC) for Natural Gas Offshore Liquefaction Plants

    International Nuclear Information System (INIS)

    SHAHBA, L.A.; Fahmy, M.F.M.

    2004-01-01

    Simulation and optimization of an innovative liquefaction process used for the LNG production , namely the Dual Mixed Refrigerant Process (DMRC) has been conducted using the HYSYS simulator .This new process is especially suitable for off shore natural gas liquefaction plants. A numerical optimization technique has been used to determine the optimum conditions for Egyptian natural gas feed source. The investigation of the effect of different compositions of the Mixed refrigerants used was conducted. Meanwhile, the investigation of the influence of the temperature of cooling water used was conducted. The best optimum conditions for the DMRC process were determined .The optimum results achieved for the DMRC process revealed that the DMRC process can be successfully applied as a promising technique for off shore natural gas liquefaction plants

  10. Proposed law of nature linking impacts, plume volcanism, and Milankovitch cycles to terrestrial vertebrate mass extinctions via greenhouse-embryo death coupling

    Science.gov (United States)

    Mclean, D. M.

    1994-01-01

    A greenhouse-physiological coupling killing mechanism active among mammals, birds, and reptiles has been identified. Operating via environmental thermal effects upon the maternal core-skin blood flow critical to the survival and development of embryos, it reduces the flow of blood to the uterine tract. Today, during hot summers, this phenomena kills embryos on a vast, global scale. Because of sensitivity of many mammals to modern heat, a major modern greenhouse could reduce population numbers on a global scale, and potentially trigger population collapses in the more vulnerable parts of the world. In the geological past, the killing mechanism has likely been triggered into action by greenhouse warming via impact events, plume volcanism, and Earth orbital variations (Milankovitch cycles). Earth's biosphere is maintained and molded by the flow of energy from the solar energy source to Earth and on to the space energy sink (SES). This SES energy flow maintains Earth's biosphere and its living components, as open, intermediate, dissipative, nonequilibrium systems whose states are dependent upon the rate of energy flowing through them. Greenhouse gases such as CO2 in the atmosphere influence the SES energy flow rate. Steady-state flow is necessary for global ecological stability (autopoiesis). Natural fluctuations of the C cycle such as rapid releases of CO2 from the mantle, or oceans, disrupt steady-state SES flow. These fluctuations constantly challenge the biosphere; slowdown of SES energy flow drives it toward thermodynamical equilibrium and stagnation. Fluctuations induced by impact event, mantle plume volcanism, and Milankovitch cycles can grow into structure-breaking waves triggering major perturbations of Earth's C cycle and mass extinctions. A major C cycle perturbation involves readjustment of the outer physiochemical spheres of the Earth: the atmosphere, hydrosphere, and lithosphere; and by necessity, the biosphere. A greenhouse, one manifestation of a major

  11. Neuroglial Transmission

    DEFF Research Database (Denmark)

    Gundersen, Vidar; Storm-Mathisen, Jon; Bergersen, Linda Hildegard

    2015-01-01

    as a signaling substance recently shown to act on specific lactate receptors in the brain. Complementing neurotransmission at a synapse, neuroglial transmission often implies diffusion of the transmitter over a longer distance and concurs with the concept of volume transmission. Transmission from glia modulates...... synaptic neurotransmission based on energetic and other local conditions in a volume of tissue surrounding the individual synapse. Neuroglial transmission appears to contribute significantly to brain functions such as memory, as well as to prevalent neuropathologies....

  12. Developing a Mobile Learning Management System for Outdoors Nature Science Activities Based on 5E Learning Cycle

    Science.gov (United States)

    Lai, Ah-Fur; Lai, Horng-Yih; Chuang, Wei-Hsiang; Wu, Zih-Heng

    2015-01-01

    Traditional outdoor learning activities such as inquiry-based learning in nature science encounter many dilemmas. Due to prompt development of mobile computing and widespread of mobile devices, mobile learning becomes a big trend on education. The main purpose of this study is to develop a mobile-learning management system for overcoming the…

  13. Predicting the ultimate potential of natural gas SOFC power cycles with CO2 capture : Part B: Applications

    NARCIS (Netherlands)

    Campanari, Stefano; Mastropasqua, Luca; Gazzani, Matteo; Chiesa, Paolo; Romano, Matteo C.

    2016-01-01

    An important advantage of solid oxide fuel cells (SOFC) as future systems for large scale power generation is the possibility of being efficiently integrated with processes for CO2 capture. Focusing on natural gas power generation, Part A of this work assessed the performances of advanced

  14. Techno-economic process design of a commercial-scale amine-based CO_2 capture system for natural gas combined cycle power plant with exhaust gas recirculation

    International Nuclear Information System (INIS)

    Ali, Usman; Agbonghae, Elvis O.; Hughes, Kevin J.; Ingham, Derek B.; Ma, Lin; Pourkashanian, Mohamed

    2016-01-01

    Highlights: • EGR is a way to enhance the CO_2 content with reduction in design variables and cost. • Both process and economic analyses are essential to reach the optimum design variables. • Commercial-scale NGCC with and without EGR is presented. • Process design of the amine-based CO_2 capture plant is evaluated for with and without EGR. - Abstract: Post-combustion CO_2 capture systems are gaining more importance as a means of reducing escalating greenhouse gas emissions. Moreover, for natural gas-fired power generation systems, exhaust gas recirculation is a method of enhancing the CO_2 concentration in the lean flue gas. The present study reports the design and scale-up of four different cases of an amine-based CO_2 capture system at 90% capture rate with 30 wt.% aqueous solution of MEA. The design results are reported for a natural gas-fired combined cycle system with a gross power output of 650 MW_e without EGR and with EGR at 20%, 35% and 50% EGR percentage. A combined process and economic analysis is implemented to identify the optimum designs for the different amine-based CO_2 capture plants. For an amine-based CO_2 capture plant with a natural gas-fired combined cycle without EGR, an optimum liquid to gas ratio of 0.96 is estimated. Incorporating EGR at 20%, 35% and 50%, results in optimum liquid to gas ratios of 1.22, 1.46 and 1.90, respectively. These results suggest that a natural gas-fired power plant with exhaust gas recirculation will result in lower penalties in terms of the energy consumption and costs incurred on the amine-based CO_2 capture plant.

  15. International Business Cycle

    Directory of Open Access Journals (Sweden)

    Marek Lubiński

    2007-04-01

    Full Text Available Prime stylized facts of international business cycle theory refer to positive correlation in the cyclical components of important macroeconomic variables across countries. However a number of indicators of business cycle synchronization do not point to clear trends. It can be ascribed to the fact that different forces influence level of business cycle correlation. When investigating into the forces behind the commonness in aggregate fluctuations economic research seems to have pointed in two directions. One strand of the literature examines the idea of common exogenous shocks that affect economies simultaneously. In addition to that economic interdependencies such as trade in goods and services or capital account transactions may serve as the channels through which disturbances spill over across countries.The observed degree of output co movement reflects both the nature of the shocks that have occurred and the degree of economic interdependence. In the periods when common shocks prevail level of synchronization is usually higher than in times of transmission dominance.

  16. Transmission issues in Alberta

    International Nuclear Information System (INIS)

    Levson, D.

    2002-01-01

    This paper outlined the major issues and concerns facing users of the transmission system in Alberta. They include congestion management issues that make investors uncertain about power generation. It is necessary to know the difference between which transmission price signals will be faced by low cost cogeneration at Fort McMurray and Cold Lake coal-fired generation near Edmonton compared to combined cycle gas generation near Calgary. Import and export policy tariffs are another concern. Most new generation opportunities in Alberta require access to export markets, but transmission facilities for export need policy support and appropriate tariffs. It was noted that the past actions of Alberta's Transmission Administrator and balancing pool may be distorting market signals for ancillary service markets, and that loss studies and calculations need upgrading

  17. Breaking Transmission with Vaccines: The Case of Tuberculosis.

    Science.gov (United States)

    Gonzalo-Asensio, Jesus; Aguilo, Nacho; Marinova, Dessislava; Martin, Carlos

    2017-07-01

    Members of the Mycobacterium tuberculosis complex (MTBC) have evolved causing tuberculosis (TB) in different mammalian hosts. MTBC ecotypes have adapted to diverse animal species, with M. bovis being the most common cause of TB in livestock. Cattle-to-human transmission of M. bovis through ingestion of raw milk was common before introduction of the pasteurization process. TB in humans is mainly caused by M. tuberculosis . This bacterium is considered a genetically clonal pathogen that has coevolved with humans due to its ability to manipulate and subvert the immune response. TB is a major public health problem due to airborne person-to-person transmission of M. tuberculosis . The essential yet unanswered question on the natural history of TB is when M. tuberculosis decides to establish latent infection in the host (resambling the lysogenic cycle of lambda phage) or to cause pulmonary disease (comparable to the lytic cycle of lambda phage). In this latter case, M. tuberculosis kills the host with the aim of achieving transmission to new hosts. Combating the TB epidemic requires stopping transmission. M. bovis BCG, the present vaccine against TB, is derived from M. bovis and only protects against disseminated forms of TB. Thus, a priority in TB research is development of new effective vaccines to prevent pulmonary disease. Attenuated vaccines based on M. tuberculosis as MTBVAC are potential candidates that could contribute to break the TB transmission cycle.

  18. Sulphur isotope measurements on sulphates from Antarctic atmospheric precipitations, lake waters and salt efflorescences: a contribution to the study of the natural sulphur cycle

    International Nuclear Information System (INIS)

    Wand, U.; Maass, I.; Haendel, D.

    1987-01-01

    Sulphur isotope analyses are an important tool for the study of the natural sulphur cycle. However, on the northern hemisphere such studies particularly of the atmospheric component of the cycle are seriously hampered and in many regions practically impossible because of the high emission rate of anthropogenic sulphur. Only in remote areas of the world such as the Antarctic 34 S analyses can be used with success to identify the various natural sulphur sources (marine, biogenic and volcanic sources). We report here preliminary results of 34 S isotope measurements on sulphates from recent atmospheric precipitations (snow), lake waters and salt efflorescences sampled in the Schirmacher Oasis and the Wohlthat Massif, central Queen Maud Land, East Antarctica. Except for 4 efflorescence samples the sulphates investigated in this work are enriched in 34 S relative to the meteoritic sulphur standard (CDT). On an average the sulphates of our study area are isotopically lighter than those from the McMurdo region, South Victoria land. The latter region is characterized by the predominance of salts of marine origin. (author)

  19. σ2-Adaptin Facilitates Basal Synaptic Transmission and Is Required for Regenerating Endo-Exo Cycling Pool Under High-Frequency Nerve Stimulation in Drosophila.

    Science.gov (United States)

    Choudhury, Saumitra Dey; Mushtaq, Zeeshan; Reddy-Alla, Suneel; Balakrishnan, Sruthi S; Thakur, Rajan S; Krishnan, Kozhalmannom S; Raghu, Padinjat; Ramaswami, Mani; Kumar, Vimlesh

    2016-05-01

    The functional requirement of adapter protein 2 (AP2) complex in synaptic membrane retrieval by clathrin-mediated endocytosis is not fully understood. Here we isolated and functionally characterized a mutation that dramatically altered synaptic development. Based on the aberrant neuromuscular junction (NMJ) synapse, we named this mutation angur (a Hindi word meaning "grapes"). Loss-of-function alleles of angur show more than twofold overgrowth in bouton numbers and a dramatic decrease in bouton size. We mapped the angur mutation to σ2-adaptin, the smallest subunit of the AP2 complex. Reducing the neuronal level of any of the subunits of the AP2 complex or disrupting AP2 complex assembly in neurons phenocopied the σ2-adaptin mutation. Genetic perturbation of σ2-adaptin in neurons leads to a reversible temperature-sensitive paralysis at 38°. Electrophysiological analysis of the mutants revealed reduced evoked junction potentials and quantal content. Interestingly, high-frequency nerve stimulation caused prolonged synaptic fatigue at the NMJs. The synaptic levels of subunits of the AP2 complex and clathrin, but not other endocytic proteins, were reduced in the mutants. Moreover, bone morphogenetic protein (BMP)/transforming growth factor β (TGFβ) signaling was altered in these mutants and was restored by normalizing σ2-adaptin in neurons. Thus, our data suggest that (1) while σ2-adaptin facilitates synaptic vesicle (SV) recycling for basal synaptic transmission, its activity is also required for regenerating SVs during high-frequency nerve stimulation, and (2) σ2-adaptin regulates NMJ morphology by attenuating TGFβ signaling. Copyright © 2016 by the Genetics Society of America.

  20. Eco-epidemiological aspects, natural detection and molecular identification of Leishmania spp. in Lutzomyia reburra, Lutzomyia barrettoi majuscula and Lutzomyia trapidoi

    Directory of Open Access Journals (Sweden)

    Jazzmín Arrivillaga-Henríquez

    2017-03-01

    Conclusion: Natural infection with Le. amazonensis was recorded for the first time in Lu. reburra and Lu. b. majuscula, demonstrating the importance of zoophilic phlebotomines in the maintenance of the Leishmania transmission cycle in endemic foci.

  1. Consideracões sobre a natureza, desenvolvimento e transmissão de Cytamoeba bacterifera Labbé, 1894 de Leptodactylus ocellatus Considerations about the nature, development and transmission of Cytamoeba bacterifera Labbé, 1894 from Leptodactylus ocellatus

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora de Sousa

    1975-01-01

    relacionadas com a etapa da infecção. Não conseguimos transmitir, por inoculação intra-peritoneal, Cytamoeba de L. ocellatus para Bufo crucifer.In view to furnish data to elucita the controversial problem of the nature of Cytamoeba bacterifera, which it is often found in erythrocytes of the frog Leptodactylus ocellatus, we have done some cytochemical tests. We displayd in its structure the contents of RNA and polysaccharides that do not undergo digestion by ptyalin. With the Feulgen's method we mainly obtained negative results, but one parasite showed a faintly diffused positivity and a few doubtful reaction were also observed. When we employed the Methyl Green-Pyronin, even after the ribonuclease treatment, and the Toluidin Blue, likewise subsequent to the activity of this enzime, we did not evidence the DNA. Taking into account that the components of C. bacterifere are usually very small and sometimes undiscernible, it is probable that their contents of DNA, perhaps existent, would be difficultly demonstrated under the light microscope, and also that it would be easily dissimulated by other substances. We do not believe in a viral nature of Cytamoeba mainly regarding some aspects of its structure (figs. 8, 15, 17 and 18 and the absence of damage on the nucleous of the infected cells. Although we did not prove the presence of DNA, we think that it is possible that C. bacterifera is an intracytoplasmic clump of modified organisms wich sizes are just within the nearness of th limit of visibility with optical microscopes, related with the bacteria, such as are, by exemple, the Chlamydiae and Rickettsiae. The development of Cytamoeba was followed in a frog maintained int he laboratory during three months and weekly examined; we observed progressive decrease of the parasitismo. Its structural types and sizes were not related with the phasis of the infection. We did not get transmission by intraperitonela inoculation of C. bacterifera from L. ocellatus to Bufo crucifer.

  2. Theorising and testing environmental pathways to behaviour change: natural experimental study of the perception and use of new infrastructure to promote walking and cycling in local communities.

    Science.gov (United States)

    Panter, Jenna; Ogilvie, David

    2015-09-03

    Some studies have assessed the effectiveness of environmental interventions to promote physical activity, but few have examined how such interventions work. We investigated the environmental mechanisms linking an infrastructural intervention with behaviour change. Natural experimental study. Three UK municipalities (Southampton, Cardiff and Kenilworth). Adults living within 5 km of new walking and cycling infrastructure. Construction or improvement of walking and cycling routes. Exposure to the intervention was defined in terms of residential proximity. Questionnaires at baseline and 2-year follow-up assessed perceptions of the supportiveness of the environment, use of the new infrastructure, and walking and cycling behaviours. Analysis proceeded via factor analysis of perceptions of the physical environment (step 1) and regression analysis to identify plausible pathways involving physical and social environmental mediators and refine the intervention theory (step 2) to a final path analysis to test the model (step 3). Participants who lived near and used the new routes reported improvements in their perceptions of provision and safety. However, path analysis (step 3, n=967) showed that the effects of the intervention on changes in time spent walking and cycling were largely (90%) explained by a simple causal pathway involving use of the new routes, and other pathways involving changes in environmental cognitions explained only a small proportion of the effect. Physical improvement of the environment itself was the key to the effectiveness of the intervention, and seeking to change people's perceptions may be of limited value. Studies of how interventions lead to population behaviour change should complement those concerned with estimating their effects in supporting valid causal inference. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. Comparison of Life Cycle energy consumption and GHG emissions of natural gas, biodiesel and diesel buses of the Madrid transportation system

    International Nuclear Information System (INIS)

    García Sánchez, Juan Antonio; López Martínez, José María; Lumbreras Martín, Julio; Flores Holgado, Maria Nuria

    2012-01-01

    This paper presents a comparative study on the use of three after-treatment technologies: i) EGR + DPF, ii) SCR + Urea and iii) 3-way catalyst when implemented in urban buses, to determinate the energy requirements, greenhouse gas emissions (GHG), direct Land Use Change (dLUC), abiotic depletion of fossil energy by means of a Life Cycle Assessment (LCA). The process of production, conditioning and transporting of the fuels used by the buses (diesel, biodiesel (B100), a blended biodiesel at 20% (B20) and natural gas) were also analyzed (Well-to-Tank analysis) along with the environmental impact due to its combustion in the bus (Tank-to-Wheel analysis). The environmental impact of the manufacturing, maintenance and recycling process of the urban buses and exhaust after-treatment systems has also been evaluated. Main results shows that Life Cycle of SCR + Urea technology reduces environmental impact to a greater extent than its global Life Cycle increases it when gasoil is used resulting in a final balance more efficient than the other options, the same behavior is observed with the use of B20 and B100 but only when 0%dLUC is assumed since if the percentage of dLUC increases the effectiveness of the SCR + Urea technology in the reduction of environmental impact tend to decrease. -- Highlights: ► We examine the environmental impact caused by the Life Cycle of each technology, fossil fuel, biofuel and vehicle. ► Biodiesel environmental impact depends largely on land transformed for grow crops. ► Using SCR + Urea technology and gasoil as a fuel in the bus further reduces the environmental impact.

  4. Mosquito transmission of the rodent malaria parasite Plasmodium chabaudi

    Directory of Open Access Journals (Sweden)

    Spence Philip J

    2012-12-01

    Full Text Available Abstract Background Serial blood passage of Plasmodium increases virulence, whilst mosquito transmission inherently regulates parasite virulence within the mammalian host. It is, therefore, imperative that all aspects of experimental malaria research are studied in the context of the complete Plasmodium life cycle. Methods Plasmodium chabaudi chabaudi displays many characteristics associated with human Plasmodium infection of natural mosquito vectors and the mammalian host, and thus provides a unique opportunity to study the pathogenesis of malaria in a single infection setting. An optimized protocol that permits efficient and reproducible vector transmission of P. c. chabaudi via Anopheles stephensi was developed. Results and conclusions This protocol was utilized for mosquito transmission of genetically distinct P. c. chabaudi isolates, highlighting differential parasite virulence within the mosquito vector and the spectrum of host susceptibility to infection initiated via the natural route, mosquito bite. An apposite experimental system in which to delineate the pathogenesis of malaria is described in detail.

  5. Comparative life cycle GHG emissions from local electricity generation using heavy oil, natural gas, and MSW incineration in Macau

    DEFF Research Database (Denmark)

    Song, Qingbin; Wang, Zhishi; Li, Jinhui

    2018-01-01

    Wh, respectively. The mean value for aggregated GHG emissions of the local power grid (imported electricity excluded) was 0.69kg CO2 per kWh, noticeably lower than many neighboring countries and regions, such as mainland China, Taiwan, and Japan. Our scenario analysis indicated that the development of natural gas......, for changing GHG emissions, and should be allocated to the highest priority for GHG reduction. All the obtained results could be useful for decisions makers, with providing a robust support for assessing the environmental performance and drawing up the appropriate improvement planning of power systems....

  6. Arctigenin, a natural lignan compound, induces G0/G1 cell cycle arrest and apoptosis in human glioma cells

    OpenAIRE

    Maimaitili, Aisha; Shu, Zunhua; Cheng, Xiaojiang; Kaheerman, Kadeer; Sikandeer, Alifu; Li, Weimin

    2016-01-01

    The aim of the current study was to investigate the anticancer potential of arctigenin, a natural lignan compound, in malignant gliomas. The U87MG and T98G human glioma cell lines were treated with various concentrations of arctigenin for 48 h and the effects of arctigenin on the aggressive phenotypes of glioma cells were assessed. The results demonstrated that arctigenin dose-dependently inhibited the growth of U87MG and T98G cells, as determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphen...

  7. The Nature of Variations in Anomalies of the Chemical Composition of the Solar Corona with the 11-Year Cycle

    Science.gov (United States)

    Pipin, V. V.; Tomozov, V. M.

    2018-04-01

    Evidence that the distribution of the abundances of admixtures with low first-ionization potentials (FIP 10 eV) in active regions and closed magnetic configurations in the lower corona. Observations with the ULYSSES spacecraft and at the Stanford Solar Observatory have revealed strong correlations between the manifestation of the FIP effect in the solar wind, the strength of the open magnetic flux (without regard to sign), and the ratio of the large-scale toroidal and poloidal magnetic fields at the solar surface. Analyses of observations of the Sun as a star show that the enhancement of the abundances of admixtures with low FIPs in the corona compared to their abundances in the photosphere (the FIP effect) is closely related to the solar-activity cycle and also with variations in the topology of the large-scale magnetic field. A possible mechanism for the relationship between the FIP effect and the spectral type of a star is discussed in the framework of solar-stellar analogies.

  8. Improving the performances of gas turbines operated on natural gas in combined cycle power plants with application of mathematical models

    International Nuclear Information System (INIS)

    Dimkovski, Sasho

    2014-01-01

    The greater energy demand by today society sets a number of new challenges in the energy sector. The climate extremes impose new modes of operation of the power plants, with high flexibility in production. Combined cycle co generative power plants are the latest trend in the energy sector. Their high prevalence is due to the great efficiency and the good environmental characteristics. The main work horse in these cogeneration plants is the gas turbine, which power production and efficiency strongly depends on the external climate conditions. In warmer periods when there is increased demand for electricity, the power production from the gas turbines significantly declines. Because of the high electricity demand from the grid and reduced power production from the gas turbines at the same time, the need for application of appropriate technology for preserving the performances and power of the gas turbines arises. This master thesis explores different methods to improve the power in gas turbines by cooling the air on the compressor inlet, analyzing their applicability and effectiveness in order to choose the optimal method for power augmentation for the climatic conditions in the city Skopje. The master thesis gives detailed analysis of the weather in Skopje and the time frame in which the chosen method is applicable. At the end in the master thesis, the economic feasibility of the given method for power augmentation is clearly calculated, using a model of a power plant and calculating the resulting amount of gained energy, the amount of the initial investment, the cost for maintenance and operation of the equipment. By these calculations the period for initial return of investment is obtained. As an added benefit the positive environmental impacts of the applied technology for inlet air cooling is analyzed. (author)

  9. Influence of atmospheric emission from coal fuel cycle on the levels of natural radionuclides and heavy metals in the population

    International Nuclear Information System (INIS)

    Jaworowski, Z.

    1983-07-01

    From the determination of Ra, Pb, Zn and Cd concentrations in air and various human tissues of inhabitants exposed to large industrial emissions as well as of those of other regions it could be seen that geographical distribution of these elements is rather related to local natural background factors than to industrial activity in the region. The concentrations of 226 Ra and Pb increased during the last century in precipitations in Southern Poland, but in the same time they decreased dramatically in the bones of the Polish population. The contemporary Polish bones contain about 10 times less Pb and 2 times less 226 Ra than 11th to 19th century Polish bones and 18th century Peruvian bones. The decrease of 226 Ra content probably results from the introduction of drinking-water treatment systems which remove majority of 226 Ra and from decrease in consumption of cereals, which are principal sources of 226 Ra intake in the diet

  10. Transmission issues

    International Nuclear Information System (INIS)

    Bradford, J.; Wilson, L.; Thon, S.; Millar, N.

    2005-01-01

    This session on transmission issues focused on the role that transmission plays in electricity markets and the importance of getting the market structure right in terms of generation divestiture with buy back contracts, demand side responsive programs, transmission upgrades and long term contracts. The difficulties of distinguishing between market power and scarcity were examined along with some of the complications that ensue if transmission experiences congestion, as exemplified by the August 2003 blackout in eastern North America. The presentations described the best ways to handle transmission issues, and debated whether transmission should be deregulated or follow market forces. Issues of interconnections and reliability of connections were also debated along with the attempt to integrate renewables into the grid. Some presentations identified what new transmission must be built and what must be done to ensure that transmission gets built. The challenges and business opportunities for transmission in Alberta were discussed with reference to plans to invest in new infrastructure, where it is going outside of the province and how it works with other jurisdictions. Manitoba's Conawapa Hydro Project and its 2000 MW tie line to Ontario was also discussed. Some examples of non-optimal use of interconnections in Europe were also discussed in an effort to learn from these mistakes and avoid them in Canada. tabs., figs

  11. Dynamic analysis of the dual-loop Organic Rankine Cycle for waste heat recovery of a natural gas engine

    International Nuclear Information System (INIS)

    Wang, Xuan; Shu, Gequn; Tian, Hua; Liu, Peng; Jing, Dongzhan; Li, Xiaoya

    2017-01-01

    Highlights: • The performance of DORC under five typical engine working conditions is analyzed. • The control object of superheat degree in LT ORC can be much lower than that in HT ORC. • The DORC has excellent working condition adaptability. • Enlarging the HT cooling water mass flux can enhance the DORC power, but not obviously. - Abstract: Natural gas internal combustion engines for electric generating are important primary movers in distributed energy systems. However, more than half of the energy is wasted by exhaust, jacket water and so on. Therefore, it is very meaningful to recover the waste heat, especially the exhaust heat. The DORC (Double loop ORC) is regarded as a suitable way to recover exhaust heat and it can produce electric required by users all the year around. As the waste heat recovery system of the engine, it often works under different working conditions owing to the varying energy demand of users. However, there is few study on the part-load performance of the DORC under different working conditions. Consequently, the dynamic math model of the DORC for waste heat recovery of a natural gas engine with 1000 kW rated power is established by Simulink in this work. With the PID control of the system, the static performance and dynamic behavior of the DORC under five typical engine working conditions are simulated and analyzed. Besides, the effects of the mass flow rate of the HT (high temperature) cooling water which is the connection between the two loops on the DORC performance are researched as well. The results illustrate that the DORC can improve the efficiency of the combined system quite well from 100% to 60% engine working condition, showing good working condition adaptability. Besides, enlarging the mass flow rate of the HT cooling water can enhance the output power of the DORC system, but not very obviously.

  12. Echinococcus canadensis transmission in the North.

    Science.gov (United States)

    Oksanen, Antti; Lavikainen, Antti

    2015-10-30

    The Echinococcus granulosus complex (EG) is the causative agent of cystic echinococcosis (CE). Northern cervid Echinococcus was previously suggested to be the ancestor of the entire EG. During the last century, it was regarded to have three (or four) different, but often overlapping, transmission cycles in the circumpolar North: the original wolf-wild cervid (reindeer or elk)-cycle; the semi-synanthropic cycle involving sled and hunting dogs and wild cervids; and the synanthropic cycle involving herding dogs and semi-domesticated reindeer. Human infections mainly derived from the latter two cycles. In Fennoscandia, the synanthropic cycle has been eliminated during the last 50 years due to changes in reindeer husbandry methods; machinery making herding dogs largely redundant. Typical to human CE in the North has been the relatively benign nature of the disease compared with CE caused by E. granulosus sensu stricto. The metacestodes in humans and in the natural cervid hosts predominantly appear in the lungs. The causative agents have been identified as EG mitochondrial genotypes G8 and G10, now together with G6 (camel), G7 (pig) and G9 genotypes constituting the Echinococcus canadensis species. Based on recent findings in reindeer in Yakutia, G6 might also be recognised among cervid genotypes. The geographical distribution of both G8 and G10 is circumpolar, with G10 currently apparently more prevalent both in the Palearctic and Nearctic. Because of the disappearance of the working dog, E. canadensis in Fennoscandia is again highly dependent on the wolf, as it was before domestication of the dog. Pet and sled dogs, if their number further increases, may to a minor part participate in the life cycle. Human CE in the North was mostly diagnosed by mass chest tuberculosis radiography campaigns, which have been discontinued. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Risk management system in the natural gas distribution of Lima and Callao according guidelines “Recommendations on transmission and distribution practice” and risk management of the PMI Project (2008)

    OpenAIRE

    Luján Ruiz, Roger Orlando

    2014-01-01

    The purpose of this research study is to analyze quantitative operational risk according to the guidelines of the practice recommendation “Recommendations on Transmission and Distribution Practice” , published by The Institution of Gas Engineers of Great Britain and the PMBOK . Chapter 11 , Managing Project Risk . This study was conducted in the Trunk pipeline system operated by Cálidda the Peru - Natural Gas from the City Gate located in Lurín , to Callao Terminal Station . The purpose of th...

  14. Government circular No. 109 of 26 May 1981 concerning acreage reservation for main natural gas transmission network in Denmark. 3. Reservation stage and addition to the 1. reservation stage. To all the municipal councils, county councils and the capital council

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The Danish Ministry of Environment recommends the administration of counties, cities and rural areas to plan no construction works or objects in the land areas shown in detailed maps, as the main transmission network of the Danish natural gas distribution system has to be constructed in the closest future. The county councils are encouraged to participate in local planning and to coordinate it with national authorities and planning board, who are entitled to introduce required changes.

  15. Government circular No. 109 of 26 May 1981 concerning acreage reservation for main natural gas transmission network in Denmark. 3. reservation stage and addition to the 1. reservation stage. To all the municipal councils, county councils and the capital council

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The Danish Ministry of Environment recommends the administration of counties, cities and rural areas to plan no construction works or objects in the land areas shown in detailed maps, as the main transmission network of the Danish natural gas distribution system has to be constructed in the closest future. The county councils are encouraged to participate in local planning and to coordinate it with national authorities and planning board, who are entitled to introduce required changes.

  16. Exergoeconomic analysis and multi objective optimization of performance of a Carbon dioxide power cycle driven by geothermal energy with liquefied natural gas as its heat sink

    International Nuclear Information System (INIS)

    Ahmadi, Mohammad H.; Mehrpooya, Mehdi; Pourfayaz, Fathollah

    2016-01-01

    Highlights: • A small scale transcritical Carbon dioxide cycle is investigated. • Exergoeconomic analysis of a CO_2 power cycle driven by geothermal energy with LNG as its heat sink. • Three decision-making methods are employed to select final answers. - Abstract: In this study a transcritical Carbon dioxide power cycle has been coupled to a liquefied natural gas to work either as the cold source and to further enhance to generate electricity. The detailed thermodynamic analysis is performed in order to investigate the effect of key parameters on the cycle performance. Also, heat exchangers are measured to find the heat transfer surface area for economic evaluation. To investigate the aforementioned cycle and for optimization purposes, an exergoeconomic analysis is done to know the important components with respect to exergoeconomic criterion. The exergoeconomic analysis reveals that Carbon dioxide turbine and condenser have the highest rate of sum cost rate associated with capital investment and the cost of exergy destruction and special attention should be paid to these components. The parametric analysis shows that there is an optimum turbine inlet pressure which brings about the highest exergy efficiency and lowest product cost rate. Moreover, the condensate pressure has the highest effect on system exergy efficiency compared to others. With the help of multi-objective optimization, the cumulative effects of these variables are investigated on the system to maximize the exergetic efficiency and to minimize the product cost rate of the system. Results show that the system is capable of producing power with exergy efficiency and product cost rate equal to 20.5% and 263592.15 $/year, respectively, according to technique for order of preference by similarity to ideal solution decision making technique. Also, the system exergy efficiency of 22.1% and 295001.26 $/year product cost rate is achieved through linear programming techniques for multidimensional

  17. Transmission eigenvalues

    Science.gov (United States)

    Cakoni, Fioralba; Haddar, Houssem

    2013-10-01

    In inverse scattering theory, transmission eigenvalues can be seen as the extension of the notion of resonant frequencies for impenetrable objects to the case of penetrable dielectrics. The transmission eigenvalue problem is a relatively late arrival to the spectral theory of partial differential equations. Its first appearance was in 1986 in a paper by Kirsch who was investigating the denseness of far-field patterns for scattering solutions of the Helmholtz equation or, in more modern terminology, the injectivity of the far-field operator [1]. The paper of Kirsch was soon followed by a more systematic study by Colton and Monk in the context of developing the dual space method for solving the inverse scattering problem for acoustic waves in an inhomogeneous medium [2]. In this paper they showed that for a spherically stratified media transmission eigenvalues existed and formed a discrete set. Numerical examples were also given showing that in principle transmission eigenvalues could be determined from the far-field data. This first period of interest in transmission eigenvalues was concluded with papers by Colton et al in 1989 [3] and Rynne and Sleeman in 1991 [4] showing that for an inhomogeneous medium (not necessarily spherically stratified) transmission eigenvalues, if they existed, formed a discrete set. For the next seventeen years transmission eigenvalues were ignored. This was mainly due to the fact that, with the introduction of various sampling methods to determine the shape of an inhomogeneous medium from far-field data, transmission eigenvalues were something to be avoided and hence the fact that transmission eigenvalues formed at most a discrete set was deemed to be sufficient. In addition, questions related to the existence of transmission eigenvalues or the structure of associated eigenvectors were recognized as being particularly difficult due to the nonlinearity of the eigenvalue problem and the special structure of the associated transmission

  18. Strengthening power generation efficiency utilizing liquefied natural gas cold energy by a novel two-stage condensation Rankine cycle (TCRC) system

    International Nuclear Information System (INIS)

    Bao, Junjiang; Lin, Yan; Zhang, Ruixiang; Zhang, Ning; He, Gaohong

    2017-01-01

    Highlights: • A two-stage condensation Rankine cycle (TCRC) system is proposed. • Net power output and thermal efficiency increases by 45.27% and 42.91%. • The effects of the condensation temperatures are analyzed. • 14 working fluids (such as propane, butane etc.) are compared. - Abstract: For the low efficiency of the traditional power generation system with liquefied natural gas (LNG) cold energy utilization, by improving the heat transfer characteristic between the working fluid and LNG, this paper has proposed a two-stage condensation Rankine cycle (TCRC) system. Using propane as working fluid, compared with the combined cycle in the conventional LNG cold energy power generation method, the net power output, thermal efficiency and exergy efficiency of the TCRC system are respectively increased by 45.27%, 42.91% and 52.31%. Meanwhile, the effects of the first-stage and second-stage condensation temperature and LNG vaporization pressure on the performance and cost index of the TCRC system (net power output, thermal efficiency, exergy efficiency and UA) are analyzed. Finally, using the net power output as the objective function, with 14 organic fluids (such as propane, butane etc.) as working fluids, the first-stage and second-stage condensation temperature at different LNG vaporization pressures are optimized. The results show that there exists a first-stage and second-stage condensation temperature making the performance of the TCRC system optimal. When LNG vaporization pressure is supercritical pressure, R116 has the best economy among all the investigated working fluids, and while R150 and R23 are better when the vaporization pressure of LNG is subcritical.

  19. The natural abundance of 15N in litter and soil profiles under six temperate tree species: N cycling depends on tree species traits and site fertility

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Nilsson, Lars Ola; Schmidt, Inger Kappel

    2013-01-01

    We investigated the influence of tree species on the natural 15N abundance in forest stands under elevated ambient N deposition.We analysed δ15N in litter, the forest floor and three mineral soil horizons along with ecosystem N status variables at six sites planted three decades ago with five Eur...... to nitrate leaching or other N transformation processes....... species leached more nitrate.The δ15N pattern reflected tree species related traits affecting the N cycling as well as site fertility and former land use, and possibly differences in N leaching. The tree species δ15N patterns reflected fractionation caused by uptake of N through mycorrhiza rather than due...

  20. A Successful Pregnancy by Utilization of Gradually Increasing Low Dose Gonadotrophin Stimulation in a Modified Natural Cycle in Vitro Fertilization Procedure: Case Report

    Directory of Open Access Journals (Sweden)

    Serkan Kahyaoğlu

    2016-05-01

    Full Text Available The modified natural cycle in vitro fertilization (MNC-IVF treatment can be a promising method for poor responder patients especially in young patients with poor ovarian reserve. A 34-year-old primary infertile woman presented with a history of poor ovarian response and cycle cancellation following controlled ovarian hyperstimulation during an IVF-ET procedure two months ago. During MNC-IVF treatment with intracytoplasmic sperm injection (ICSI, gradually increasing doses of hMG for three days (totally 675 IU have been administered accompanied by daily 0,25 mg cetrorelix. Following ovulation triggering, one oocyte was picked up and a good quality (grade 1 embryo was transferred on day 2. A clinical pregnancy was established with ultrasonography on sixth weeks of gestation. Acceptable pregnancy rates per embryo transfer, low medication cost, relatively low risk of complications and higher patient acceptability are the main advantages of MNC-IVF treatment as a feasible treatment option especially for poor responder patients.

  1. Porosity and Organic Carbon Controls on Naturally Reduced Zone (NRZ) Formation Creating Microbial ';Hotspots' for Fe, S, and U Cycling in Subsurface Sediments

    Science.gov (United States)

    Jones, M. E.; Janot, N.; Bargar, J.; Fendorf, S. E.

    2013-12-01

    Previous studies have illustrated the importance of Naturally Reduced Zones (NRZs) within saturated sediments for the cycling of metals and redox sensitive contaminants. NRZs can provide a source of reducing equivalents such as reduced organic compounds or hydrogen to stimulate subsurface microbial communities. These NRZ's are typically characterized by low permeability and elevated concentrations of organic carbon and trace metals. However, both the formation of NRZs and their importance to the overall aquifer carbon remineralization is not fully understood. Within NRZs the hydrolysis of particulate organic carbon (POC) and subsequent fermentation of dissolved organic carbon (DOC) to form low molecular weight dissolved organic carbon (LMW-DOC) provides electron donors necessary for the respiration of Fe, S, and in the case of the Rifle aquifer, U. Rates of POC hydrolysis and subsequent fermentation have been poorly constrained and rates in excess and deficit to the rates of subsurface anaerobic respiratory processes have been suggested. In this study, we simulate the development of NRZ sediments in diffusion-limited aggregates to investigate the physical and chemical conditions required for NRZ formation. Effects of sediment porosity and POC loading on Fe, S, and U cycling on molecular and nanoscale are investigated with synchrotron-based Near Edge X-ray Absorption Fine Structure Spectroscopy (NEXAFS). Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS) and Fourier Transform Infrared spectroscopy (FTIR) are used to characterize the transformations in POC and DOC. Sediment aggregates are inoculated with the natural microbial biota from the Rifle aquifer and population dynamics are monitored by 16S RNA analysis. Overall, establishment of low permeability NRZs within the aquifer stimulate microbial respiration beyond the diffusion-limited zones and can limit the transport of U through a contaminated aquifer. However, the long-term stability of

  2. Quantifying Transmission.

    Science.gov (United States)

    Woolhouse, Mark

    2017-07-01

    Transmissibility is the defining characteristic of infectious diseases. Quantifying transmission matters for understanding infectious disease epidemiology and designing evidence-based disease control programs. Tracing individual transmission events can be achieved by epidemiological investigation coupled with pathogen typing or genome sequencing. Individual infectiousness can be estimated by measuring pathogen loads, but few studies have directly estimated the ability of infected hosts to transmit to uninfected hosts. Individuals' opportunities to transmit infection are dependent on behavioral and other risk factors relevant given the transmission route of the pathogen concerned. Transmission at the population level can be quantified through knowledge of risk factors in the population or phylogeographic analysis of pathogen sequence data. Mathematical model-based approaches require estimation of the per capita transmission rate and basic reproduction number, obtained by fitting models to case data and/or analysis of pathogen sequence data. Heterogeneities in infectiousness, contact behavior, and susceptibility can have substantial effects on the epidemiology of an infectious disease, so estimates of only mean values may be insufficient. For some pathogens, super-shedders (infected individuals who are highly infectious) and super-spreaders (individuals with more opportunities to transmit infection) may be important. Future work on quantifying transmission should involve integrated analyses of multiple data sources.

  3. Emissions of toxic pollutants from compressed natural gas and low sulfur diesel-fueled heavy-duty transit buses tested over multiple driving cycles.

    Science.gov (United States)

    Kado, Norman Y; Okamoto, Robert A; Kuzmicky, Paul A; Kobayashi, Reiko; Ayala, Alberto; Gebel, Michael E; Rieger, Paul L; Maddox, Christine; Zafonte, Leo

    2005-10-01

    The number of heavy-duty vehicles using alternative fuels such as compressed natural gas (CNG) and new low-sulfur diesel fuel formulations and equipped with after-treatment devices are projected to increase. However, few peer-reviewed studies have characterized the emissions of particulate matter (PM) and other toxic compounds from these vehicles. In this study, chemical and biological analyses were used to characterize the identifiable toxic air pollutants emitted from both CNG and low-sulfur-diesel-fueled heavy-duty transit buses tested on a chassis dynamometer over three transient driving cycles and a steady-state cruise condition. The CNG bus had no after-treatment, and the diesel bus was tested first equipped with an oxidation catalyst (OC) and then with a catalyzed diesel particulate filter (DPF). Emissions were analyzed for PM, volatile organic compounds (VOCs; determined on-site), polycyclic aromatic hydrocarbons (PAHs), and mutagenic activity. The 2000 model year CNG-fueled vehicle had the highest emissions of 1,3-butadiene, benzene, and carbonyls (e.g., formaldehyde) of the three vehicle configurations tested in this study. The 1998 model year diesel bus equipped with an OC and fueled with low-sulfur diesel had the highest emission rates of PM and PAHs. The highest specific mutagenic activities (revertants/microg PM, or potency) and the highest mutagen emission rates (revertants/mi) were from the CNG bus in strain TA98 tested over the New York Bus (NYB) driving cycle. The 1998 model year diesel bus with DPF had the lowest VOCs, PAH, and mutagenic activity emission. In general, the NYB driving cycle had the highest emission rates (g/mi), and the Urban Dynamometer Driving Schedule (UDDS) had the lowest emission rates for all toxics tested over the three transient test cycles investigated. Also, transient emissions were, in general, higher than steady-state emissions. The emissions of toxic compounds from an in-use CNG transit bus (without an oxidation

  4. Climate and environmental effects of electric vehicles versus compressed natural gas vehicles in China: a life-cycle analysis at provincial level.

    Science.gov (United States)

    Huo, Hong; Zhang, Qiang; Liu, Fei; He, Kebin

    2013-02-05

    Electric vehicles (EVs) and compressed natural gas vehicles (CNGVs), which are mainly coal-based and natural gas-based, are the two most widely proposed replacements of gasoline internal combustion engine vehicles (ICEVs) in P.R. China. We examine fuel-cycle emissions of greenhouse gases (GHGs), PM(2.5), PM(10), NO(x), and SO(2) of CNGVs and EVs relative to gasoline ICEVs and hybrids, by Chinese province. CNGVs can currently reduce emissions of GHGs, PM(10), PM(2,5), NO(x), and SO(2) by approximately 6%, 7%, 20%, 18% and 22%, respectively. EVs can reduce GHG emissions by 20%, but increase PM(10), PM(2.5), NO(x), and SO(2) emissions by approximately 360%, 250%, 120%, and 370%, respectively. Nevertheless, results vary significantly by province. Regarding their contribution to national emissions, PM increases from EVs are unimportant, because light-duty passenger vehicles contribute very little to overall PM emissions nationwide (≤0.05%); however, their NO(x) and SO(2) increases are important. Since China is striving to reduce power plant emissions, EVs are expected to have equivalent or even lower SO(2) and NO(x) emissions relative to ICEVs in the future (2030). Before then, however, EVs should be developed according to the cleanness of regional power mixes. This would lower their SO(2) and NO(x) emissions and earn more GHG reduction credits.

  5. Data transmission

    National Research Council Canada - National Science Library

    Tugal, Dogan A; Tugal, Osman

    1989-01-01

    This updated second edition provides working answers to today's critical questions about designing and managing all types of data transmission systems and features a new chapter on local area networks (LANs...

  6. Assessment of the quality and quantity of naturally induced antibody responses to EBA175RIII-V in Ghanaian children living in two communities with varying malaria transmission patterns

    DEFF Research Database (Denmark)

    Abagna, Hamza B; Acquah, Festus K; Okonu, Ruth

    2018-01-01

    of malaria parasites, which can enhance immune responses against parasite antigens. This study determined the prevalence and relative avidities of naturally induced antibodies to EBA175RIII-VLl in asymptomatic children living in two communities with varying malaria transmission patterns. METHODS: An asexual...... each study site however, children living in Obom had significantly higher EBA175RIII-VLl antibody concentrations than children living in Abura (P 0.05, Mann-Whitney test). Over the course of the study, the relative antibody avidities of EBA175RIII-VLl IgG antibodies were similar within and between......BACKGROUND: Recent global reports on malaria suggest significant decrease in disease severity and an increase in control interventions in many malaria endemic countries, including Ghana. However, a major driving force sustaining malaria transmission in recent times is the asymptomatic carriage...

  7. The role of natural gas as a primary fuel in the near future, including comparisons of acquisition, transmission and waste handling costs of as with competitive alternatives

    Science.gov (United States)

    2012-01-01

    Natural gas comprises about a quarter of the United States’ energy use. It is more environmentally friendly than oil and coal due to lower carbon dioxide (CO2) emissions per unit, less costly per unit of energy and more readily available domestically in abundant supply. However, due to a number of barriers in the political, infrastructural, pricing and other arenas, the use of natural gas as a significant energy source in the United States has been limited. In our paper, we highlight the favorable qualities of natural gas and its benefits for the consumer, producer, and environment, having compared the costs of the various components of the natural gas business such as drilling and transport to that of coal and oil. Moreover, we touch upon the major issues that have prevented a more prevalent use of the gas, such as the fact that the infrastructure of natural gas is more costly since it is transported though pipelines whereas other energy sources such as oil and coal have flexible systems that use trains, trucks and ships. In addition, the powerful lobbies of the coal and oil businesses, along with the inertia in the congress to pass a national climate change bill further dampens incentives for these industries to invest in natural gas, despite its various attractive qualities. We also include discussions of policy proposals to incentive greater use of natural gas in the future. PMID:22540989

  8. Lateral force transmission between human tendon fascicles

    DEFF Research Database (Denmark)

    Haraldsson, Bjarki T; Aagaard, Per; Qvortrup, Klaus

    2008-01-01

    Whether adjacent collagen fascicles transmit force in parallel is unknown. The purpose of the present study was to examine the magnitude of lateral force transmission between adjacent collagen fascicles from the human patellar and Achilles tendon. From each sample two adjacent strands of fascicles...... was transversally cut while the other fascicle and the fascicular membrane were kept intact. Cycle 3: both fascicles were cut in opposite ends while the fascicular membrane was left intact. A decline in peak force of 45% and 55% from cycle 1 to cycle 2, and 93% and 92% from cycle 2 to cycle 3 was observed...... in the patellar and Achilles tendon fascicles, respectively. A decline in stiffness of 39% and 60% from cycle 1 to cycle 2, and of 93% and 100% from cycle 2 to cycle 3 was observed in the patellar and Achilles tendon fascicles, respectively. The present data demonstrate that lateral force transmission between...

  9. Study on the P-odd asymmetry of longitudinally polarized neutron transmission in 117Sn, 233Th, 239Pu isotopes and natural mixture of Cl and Pb isotopes

    International Nuclear Information System (INIS)

    Abov, Yu.G.; Ermakov, O.N.; Karpikhin, I.L.; Krupchitskij, P.A.; Kuznetsov, Yu.Eh.; Perepelitsa, V.F.; Petrushin, V.I.

    1983-01-01

    The results of measurements of P-odd helicity dependence of the total cross-section a=(σsub(tot)sup(+)-σsub(tot)sup(-))/(σsub(tot)sup(+)+σsub(tot)sup(-)) for thermal neutrons on several targets are presented. The result for 117 Sn is a=(11.2+-2.6)x10 -6 . The upper limits for a in the region of several units of 10 -6 are obtained for 232 Th, 239 Pu, Cl (natural) and Pb (natural)

  10. Analysis of an integrated cryogenic air separation unit, oxy-combustion carbon dioxide power cycle and liquefied natural gas regasification process by exergoeconomic method

    International Nuclear Information System (INIS)

    Mehrpooya, Mehdi; Zonouz, Masood Jalali

    2017-01-01

    Highlights: • Exergoeconomic analyses is done on an integrated cryogenic air separation unit. • Liquefied natural gas cold energy is used in the process. • The main multi stream heat exchanger is the worst device based on the results. - Abstract: Exergoeconomic and sensitivity analyses are performed on the integrated cryogenic air separation unit, oxy-combustion Carbon dioxide power cycle and liquefied natural gas regasification process. Exergy destruction, exergy efficiency, cost rate of exergy destruction, cost rate of capital investment and operating and maintenance, exergoeconomic factor and relative cost difference have been calculated for the major components of the process. The exergy efficiency of the process is around 67.1% and after mixers, tees, tank and expansion valves the multi-stream heat exchanger H-3 have the best exergy efficiency among all process components. Total exergy destruction rate of the process is 1.93 × 10"7 kW. Results of exergoeconomic analysis demonstrates that maximum exergy destruction and capital investment operating and maintenance cost rate are related to the multi-stream heat exchanger H-1 and pump P-1 with the values of 335,144 ($/h) and 12,838 ($/h), respectively. In the sensitivity analysis section the effects of the varying economic parameters, such as interest rate and plant life time are investigated on the trend of the capital investment operating and maintenance cost rate of the major components of the process and in another cases the effect of the gas turbine isentropic efficiency on the exergy and exergoeconomic parameters are studied.

  11. 15N natural abundance in warm-core rings of the Gulf Stream: studies of the upper-ocean nitrogen cycle

    International Nuclear Information System (INIS)

    Altabet, M.A.

    1984-01-01

    An extensive study of 15 N natural abundance in particulate organic nitrogen (PON) from warm-core rings of the Gulf Stream was carried out to test its use as an in situ tracer of the marine nitrogen cycle. Ring 82-B exhibited large temporal changes in the delta 15 N of PON. It was found that delta 15 N values for euphotic zone PON were low in April before stratification and higher in June after stratification had occurred. Below 400 meters, in the permanent thermocline, the change was opposite going from very high values to ones similar to those at the surface. Examination of vertical profiles for delta 15 N in the upper 200 meters demonstrated that in stratified waters a delta 15 N minimum for PON occurs with both the top of the nitracline and a maximum in PON concentration. Often a minimum in C/N ratio also occurs at the depth of the delta 15 N minimum. A mathematical model of nitrogen flux into and out of the euphotic zone and associated isotopic fractionation qualitatively reproduced the observed patterns for the delta 15 N of PON, PON concentration and NO 3 - concentration. Levels of PON increased as a result of either increasing NO 3 - flux into the euphotic zone or increasing the residence time of PON in the euphotic zone. These results lend general support to current views regarding the nature and significance of the vertical fluxes of nitrogen in the upper-ocean and the hypotheses presented concerning the factors which control the delta 15 N of PON

  12. Electrical transmission

    Energy Technology Data Exchange (ETDEWEB)

    Sayers, D P

    1960-05-01

    After briefly tracing the history of electricity transmission, trends in high voltage transmission and experiments being conducted on 650 kV are discussed. 5000 miles of the U.K. grid are operated at 132 kV and 1000 at 275 kV, ultimately to provide a super grid at 380 kV. Problems are insulation, radio interference and the cost of underground lines (16 times that of overhead lines). Also considered are the economics of the grid as a means of transporting energy and as a means of spreading the peak load over the power stations in the most efficient manner. Finally, the question of amenities is discussed.

  13. Comparing the sustainability impacts of solar thermal and natural gas combined cycle for electricity production in Mexico: Accounting for decision makers' priorities

    Science.gov (United States)

    Rodríguez-Serrano, Irene; Caldés, Natalia; Oltra, Christian; Sala, Roser

    2017-06-01

    The aim of this paper is to conduct a comprehensive sustainability assessment of the electricity generation with two alternative electricity generation technologies by estimating its economic, environmental and social impacts through the "Framework for Integrated Sustainability Assessment" (FISA). Based on a Multiregional Input Output (MRIO) model linked to a social risk database (Social Hotspot Database), the framework accounts for up to fifteen impacts across the three sustainability pillars along the supply chain of the electricity production from Solar Thermal Electricity (STE) and Natural Gas Combined Cycle (NGCC) technologies in Mexico. Except for value creation, results show larger negative impacts for NGCC, particularly in the environmental pillar. Next, these impacts are transformed into "Aggregated Sustainability Endpoints" (ASE points) as a way to support the decision making in selecting the best sustainable project. ASE points obtained are later compared to the resulting points weighted by the reported priorities of Mexican decision makers in the energy sector obtained from a questionnaire survey. The comparison shows that NGCC achieves a 1.94 times worse negative score than STE, but after incorporating decision makerś priorities, the ratio increases to 2.06 due to the relevance given to environmental impacts such as photochemical oxidants formation and climate change potential, as well as social risks like human rights risks.

  14. Tofacitinib induces G1 cell-cycle arrest and inhibits tumor growth in Epstein-Barr virus-associated T and natural killer cell lymphoma cells.

    Science.gov (United States)

    Ando, Shotaro; Kawada, Jun-Ichi; Watanabe, Takahiro; Suzuki, Michio; Sato, Yoshitaka; Torii, Yuka; Asai, Masato; Goshima, Fumi; Murata, Takayuki; Shimizu, Norio; Ito, Yoshinori; Kimura, Hiroshi

    2016-11-22

    Epstein-Barr virus (EBV) infects not only B cells, but also T cells and natural killer (NK) cells, and is associated with T or NK cell lymphoma. These lymphoid malignancies are refractory to conventional chemotherapy. We examined the activation of the JAK3/STAT5 pathway in EBV-positive and -negative B, T and NK cell lines and in cell samples from patients with EBV-associated T cell lymphoma. We then evaluated the antitumor effects of the selective JAK3 inhibitor, tofacitinib, against these cell lines in vitro and in a murine xenograft model. We found that all EBV-positive T and NK cell lines and patient samples tested displayed activation of the JAK3/STAT5 pathway. Treatment of these cell lines with tofacitinib reduced the levels of phospho-STAT5, suppressed proliferation, induced G1 cell-cycle arrest and decreased EBV LMP1 and EBNA1 expression. An EBV-negative NK cell line was also sensitive to tofacitinib, whereas an EBV-infected NK cell line was more sensitive to tofacitinib than its parental line. Tofacitinib significantly inhibited the growth of established tumors in NOG mice. These findings suggest that tofacitinib may represent a useful therapeutic agent for patients with EBV-associated T and NK cell lymphoma.

  15. Effects of non-fatiguing respiratory muscle loading induced by expiratory flow limitation during strenuous incremental cycle exercise on metabolic stress and circulating natural killer cells.

    Science.gov (United States)

    Rolland-Debord, Camille; Morelot-Panzini, Capucine; Similowski, Thomas; Duranti, Roberto; Laveneziana, Pierantonio

    2017-12-01

    Exercise induces release of cytokines and increase of circulating natural killers (NK) lymphocyte during strong activation of respiratory muscles. We hypothesised that non-fatiguing respiratory muscle loading during exercise causes an increase in NK cells and in metabolic stress indices. Heart rate (HR), ventilation (VE), oesophageal pressure (Pes), oxygen consumption (VO 2 ), dyspnoea and leg effort were measured in eight healthy humans (five men and three women, average age of 31 ± 4 years and body weight of 68 ± 10 kg), performing an incremental exercise testing on a cycle ergometer under control condition and expiratory flow limitation (FL) achieved by putting a Starling resistor. Blood samples were obtained at baseline, at peak of exercise and at iso-workload corresponding to that reached at the peak of FL exercise during control exercise. Diaphragmatic fatigue was evaluated by measuring the tension time index of the diaphragm. Respiratory muscle overloading caused an earlier interruption of exercise. Diaphragmatic fatigue did not occur in the two conditions. At peak of flow-limited exercise compared to iso-workload, HR, peak inspiratory and expiratory Pes, NK cells and norepinephrine were significantly higher. The number of NK cells was significantly related to ΔPes (i.e. difference between the most and the less negative Pes) and plasmatic catecholamines. Loading of respiratory muscles is able to cause an increase of NK cells provided that activation of respiratory muscles is intense enough to induce a significant metabolic stress.

  16. Sarcocystis neurona infections in raccoons (Procyon lotor): evidence for natural infection with sarcocysts, transmission of infection to opossums (Didelphis virginiana), and experimental induction of neurologic disease in raccoons.

    Science.gov (United States)

    Dubey, J P; Saville, W J; Stanek, J F; Lindsay, D S; Rosenthal, B M; Oglesbee, M J; Rosypal, A C; Njoku, C J; Stich, R W; Kwok, O C; Shen, S K; Hamir, A N; Reed, S M

    2001-10-24

    Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease of horses in the Americas and Sarcocystis neurona is the most common etiologic agent. The distribution of S. neurona infections follows the geographical distributions of its definitive hosts, opossums (Didelphis virginiana, Didelphis albiventris). Recently, cats and skunks were reported as experimental and armadillos as natural intermediate hosts of S. neurona. In the present report, raccoons (Procyon lotor) were identified as a natural intermediate host of S. neurona. Two laboratory-raised opossums were found to shed S. neurona-like sporocysts after ingesting tongues of naturally-infected raccoons. Interferon-gamma gene knockout (KO) mice fed raccoon-opossum-derived sporocysts developed neurologic signs. S. neurona was identified immunohistochemically in tissues of KO mice fed sporocysts and the parasite was isolated in cell cultures inoculated with infected KO mouse tissues. The DNA obtained from the tongue of a naturally-infected raccoon, brains of KO mice that had neurological signs, and from the organisms recovered in cell cultures inoculated with brains of neurologic KO mice, corresponded to that of S. neurona. Two raccoons fed mature S. neurona sarcocysts did not shed sporocysts in their feces, indicating raccoons are not likely to be its definitive host. Two raccoons fed sporocysts from opossum feces developed clinical illness and S. neurona-associated encephalomyelitis was found in raccoons killed 14 and 22 days after feeding sporocysts; schizonts and merozoites were seen in encephalitic lesions.

  17. Analysis of fuel cycles with natural uranium, Phase I, Economic analysis of plutonium recycling in BHWR; Analiza gorivnih ciklusa sa prirodnim uranom, II faza - Ekonomska analiza recikliranja plutonijuma u BHWR reaktorima

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N; Bosevski, T [Institute of Nuclear Sciences Boris Kidric, Laboratorija za fiziku i dinamiku reaktora, Vinca, Beograd (Serbia and Montenegro)

    1965-11-15

    The objective of this analysis was establishing a method for determination of the fuel price fraction in the total cost of nuclear power production. Special attention was devoted to recycling of plutonium in natural uranium reactors, plutonium to be used in the same reactor type. The adopted method would enable economic comparison of different types of fuel cycles for different reactors.

  18. Natural and anthropogenic variations in the N cycle - A perspective provided by nitrogen isotopes in trees near oil-sand developments

    Science.gov (United States)

    Savard, M. M.; Bégin, C.; Marion, J.; Smirnoff, A.

    2011-12-01

    Nitrogen stable isotopes of tree-ring series have been recently used to detect past air pollution effects on forests in the contexts of point sources, highways or peri-urban regions. Here, we want to assess their potential to understand changes in soil processes and reveal perturbations of the N cycle. Our approach involves combining tree-ring N, C and O stable isotope series with statistical modelling to distinguish the responses of trees due to natural (climatic) conditions from the ones potentially caused by emissions from the Athabasca oil-sand developments where truck fleets, oil upgraders, desulphurization and hydrogen plants, boilers, heaters and turbines have been active since 1967. Three white spruce trees [Picea glauca (Moench)] 165 years or older, were selected in a well drained brunisolic site, at 55 km from the heart of the development operations (white and black spruce trees from other sites are currently being investigated). Their growth rings were dated and separated at a time resolution of 1 or 2 years for the 1880-2009 period. The average oxygen isotope ratios of cellulose do not show long-term anomalies and reflect climatic conditions. The average C isotope ratios of cellulose covering the 1880-1965 period show short-term variations mostly explained by local climatic conditions, whereas the 1966-1995 series presents similar short-term variations superimposed on a long-term isotopic increase significantly departing from the oxygen isotope curve. Most importantly, the nitrogen isotope series of treated wood shows an average decrease of 1.0% during the 1970-2009 period. The statistical links between the variations of the regional drought index and the isotopic C and N responses during the pre-operation period allows to develop predictive climatic models. When we apply these models to predict the natural isotopic behaviour of the recent period, the measured isotopic trends of the operation period depart from the modelled curves. In contrast, using

  19. Role of Dissolved Organic Matter and Geochemical Controls on Arsenic Cycling from Sediments to Groundwater along the Meghna River, Bangladesh: Tracking possible links to permeable natural reactive barrier

    Science.gov (United States)

    Datta, S.; Berube, M.; Knappett, P.; Kulkarni, H. V.; Vega, M.; Jewell, K.; Myers, K.

    2017-12-01

    Elevated levels of dissolved arsenic (As), iron (Fe) and manganese (Mn) are seen in the shallow groundwaters of southeast Bangladesh on the Ganges Brahmaputra Meghna River delta. This study takes a multi disciplinary approach to understand the extent of the natural reactive barrier (NRB) along the Meghna River and evaluate the role of the NRB in As sequestration and release in groundwater aquifers. Shallow sediment cores, and groundwater and river water samples were collected from the east and west banks of the Meghna. Groundwater and river water samples were tested for FeT, MnT, and AsT concentrations. Fluorescence spectroscopic characterization of groundwater dissolved organic matter (DOM) provided insight into the hydro geochemical reactions active in the groundwater and the hyporheic zones. Eight sediment cores of 1.5 m depth were collected 10 m away from the edge of the river. Vertical solid phase concentration profiles of Fe, Mn and As were measured via 1.2 M HCl digestion which revealed solid phase As accumulation along the riverbanks up to concentrations of 1500 mg/kg As. Microbial interactions with DOM prompts the reduction of Fe3+ to Fe2+, causing As to mobilize into groundwater and humic-like DOM present in the groundwater may catalyze this process. The extent to which microbially mediated release of As occurs is limited by labile dissolved organic carbon (DOC) availability. Aqueous geochemical results showed the highest dissolved As concentrations in shallow wells (groundwater was found to contain microbial and terrestrial derived DOC, and decomposed, humified and aromatic DOM. Deeper aquifers had a significantly larger microbial OM signature than the shallower aquifers and was less aromatic, decomposed and humified. The results from this study illustrate the potential for humic substances to contribute to As cycling and quantify the extent of As accumulation in the sediments and groundwater along a 1 km stretch of the Meghna. These findings contribute

  20. Development of a plant dynamics computer code for analysis of a supercritical carbon dioxide Brayton cycle energy converter coupled to a natural circulation lead-cooled fast reactor.

    Energy Technology Data Exchange (ETDEWEB)

    Moisseytsev, A.; Sienicki, J. J.

    2007-03-08

    STAR-LM is a lead-cooled pool-type fast reactor concept operating under natural circulation of the coolant. The reactor core power is 400 MWt. The open-lattice core consists of fuel pins attached to the core support plate, (the does not consist of removable fuel assemblies). The coolant flows outside of the fuel pins. The fuel is transuranic nitride, fabricated from reprocessed LWR spent fuel. The cladding material is HT-9 stainless steel; the steady-state peak cladding temperature is 650 C. The coolant is single-phase liquid lead under atmospheric pressure; the core inlet and outlet temperatures are 438 C and 578 C, respectively. (The Pb coolant freezing and boiling temperatures are 327 C and 1749 C, respectively). The coolant is contained inside of a reactor vessel. The vessel material is Type 316 stainless steel. The reactor is autonomous meaning that the reactor power is self-regulated based on inherent reactivity feedbacks and no external power control (through control rods) is utilized. The shutdown (scram) control rods are used for startup and shutdown and to stop the fission reaction in case of an emergency. The heat from the reactor is transferred to the S-CO{sub 2} Brayton cycle in in-reactor heat exchangers (IRHX) located inside the reactor vessel. The IRHXs are shell-and-tube type heat exchangers with lead flowing downwards on the shell side and CO{sub 2} flowing upwards on the tube side. No intermediate circuit is utilized. The guard vessel surrounds the reactor vessel to contain the coolant, in the very unlikely event of reactor vessel failure. The Reactor Vessel Auxiliary Cooling System (RVACS) implementing the natural circulation of air flowing upwards over the guard vessel is used to cool the reactor, in the case of loss of normal heat removal through the IRHXs. The RVACS is always in operation. The gap between the vessels is filled with liquid lead-bismuth eutectic (LBE) to enhance the heat removal by air by significantly reducing the thermal

  1. The influence of the internal microbiome on the materials used for construction of the transmission natural gas pipelines in the Lodz Province

    OpenAIRE

    Staniszewska Agnieszka; Jastrzębska Magdalena; Ziemiński Krzysztof

    2017-01-01

    This paper presents investigation results of the influence of gas microbes on the biocorrosion rate of the materials used for gas pipelines construction in the Lodz Province. Samples of two types of carbon steel and cast iron were stored in the laboratory pipeline model reflecting the real conditions of working natural gas pipelines were. In the next step the influence of cathodic protection with parameters recommended for protection of underground structures was tested. Analyses of biologica...

  2. Post-learning stress differentially affects memory for emotional gist and detail in naturally cycling women and women on hormonal contraceptives

    Science.gov (United States)

    Nielsen, Shawn E.; Ahmed, Imran; Cahill, Larry

    2014-01-01

    Sex differences in emotional memory have received increasing interest over the past decade. However, to date, no work has explored how a post-learning stressor might modulate the influence of sex hormone status on memory for gist and peripheral detail in an emotional versus neutral context. Here, we tested three predictions. First, compared to naturally cycling women (NC women) in the luteal phase, women on hormonal contraception (HC women) would have significantly blunted HPA reactivity to physical stress. Second, post-learning stress would enhance detail and gist memory from an emotional story in NC women, and finally, post-learning stress would not affect emotional memory for details or gist in HC women. Healthy NC and HC women viewed a brief, narrated story containing neutral or emotionally arousing elements. Immediately after, Cold Pressor Stress (CPS) or a control procedure was administered. One week later, participants received a surprise free recall test for story elements. NC women exhibited significantly greater cortisol increases to CPS compared to HC women. NC women who viewed the emotional story and were administered CPS recalled the most peripheral details overall and more gist from the emotional compared to the neutral story. In HC women, however, the post-learning cortisol release did not affect memory for gist or peripheral details from the emotional or neutral story in any way. Additionally, NC and HC women performed similarly on measures of attention and arousal. These findings suggest that in women, post-learning stress differentially affects memory for emotional information depending on their hormonal contraceptive status. PMID:24841741

  3. Nature of the Ag-Si interface in screen-printed contacts. A detailed transmission electron microscopy study of cross-sectional structures

    Energy Technology Data Exchange (ETDEWEB)

    Ballif, C. [Fraunhofer ISE, Laboratory and Service Center Gelsenkirchen (Germany); Huljic, D.M.; Willeke, G. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany); Hessler-Wyser, A. [Swiss Federal Inst. of Technology, CIME, Lausanne (Switzerland)

    2002-07-01

    As screen printed contacts are the predominant metallisation technique in industrial production of Si solar cells, a better understanding of their properties is necessary. In this work, we show that high-quality cross-sectional samples can be prepared, whose study by transmission electron microscopy (TEM) reveals precisely the structure of the contact between the silver fingers and the Si. On diffused [100] Si wafers, direct firing of an Ag paste results in interfaces which are mainly composed of shaped Ag crystallites penetrating the emitter up to 120 nm. These crystallites are in epitaxial relation with the Sl substrate. When firing the contacts through a SiN{sub x} layer, larger Ag crystallites are present at the interface with Si and the orientation relation is lost. In both cases, high resolution TEM imaging and EDX analyses reveal a crystalline Ag/Si interface, where neither oxide nor glass frit can be detected. The presence of a significant glass frit layer between the Ag crystallites contacting the Si and the large Ag grains forming the bulk of the fingers can partly explain why lowly doped emitters are difficult to contact by screen-printing. (orig.)

  4. Interactions between natural enemies: Effect of a predatory mite on transmission of the fungus Neozygites floridana in two-spotted spider mite populations.

    Science.gov (United States)

    Trandem, Nina; Berdinesen, Ronny; Pell, Judith K; Klingen, Ingeborg

    2016-02-01

    Introducing the predatory mite Phytoseiulus persimilis into two-spotted spider mite, Tetranychus urticae, populations significantly increased the proportion of T. urticae infected with the spider mite pathogen Neozygites floridana in one of two experiments. By the final sampling occasion, the number of T. urticae in the treatment with both the predator and the pathogen had declined to zero in both experiments, while in the fungus-only treatment T. urticae populations still persisted (20-40 T. urticae/subsample). Releasing P. persimilis into crops in which N. floridana is naturally present has the potential to improve spider mite control more than through predation alone. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Uranium Bio-accumulation and Cycling as revealed by Uranium Isotopes in Naturally Reduced Sediments from the Upper Colorado River Basin

    Science.gov (United States)

    Lefebvre, Pierre; Noël, Vincent; Jemison, Noah; Weaver, Karrie; Bargar, John; Maher, Kate

    2016-04-01

    Uranium (U) groundwater contamination following oxidized U(VI) releases from weathering of mine tailings is a major concern at numerous sites across the Upper Colorado River Basin (CRB), USA. Uranium(IV)-bearing solids accumulated within naturally reduced zones (NRZs) characterized by elevated organic carbon and iron sulfide compounds. Subsequent re-oxidation of U(IV)solid to U(VI)aqueous then controls the release to groundwater and surface water, resulting in plume persistence and raising public health concerns. Thus, understanding the extent of uranium oxidation and reduction within NRZs is critical for assessing the persistence of the groundwater contamination. In this study, we measured solid-phase uranium isotope fractionation (δ238/235U) of sedimentary core samples from four study sites (Shiprock, NM, Grand Junction, Rifle and Naturita, CO) using a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). We observe a strong correlation between U accumulation and the extent of isotopic fractionation, with Δ238U up to +1.8 ‰ between uranium-enriched and low concentration zones. The enrichment in the heavy isotopes within the NRZs appears to be especially important in the vadose zone, which is subject to variations in water table depth. According to previous studies, this isotopic signature is consistent with biotic reduction processes associated with metal-reducing bacteria. Positive correlations between the amount of iron sulfides and the accumulation of reduced uranium underline the importance of sulfate-reducing conditions for U(IV) retention. Furthermore, the positive fractionation associated with U reduction observed across all sites despite some variations in magnitude due to site characteristics, shows a regional trend across the Colorado River Basin. The maximum extent of 238U enrichment observed in the NRZ proximal to the water table further suggests that the redox cycling of uranium, with net release of U(VI) to the groundwater by

  6. Alternative fuel cycles

    International Nuclear Information System (INIS)

    Penn, W.J.

    1979-05-01

    Uranium resource utilization and economic considerations provide incentives to study alternative fuel cycles as future options to the PHWR natural uranium cycle. Preliminary studies to define the most favourable alternatives and their possible introduction dates are discussed. The important and uncertain components which influence option selection are reviewed, including nuclear capacity growth, uranium availability and demand, economic potential, and required technological developments. Finally, a summary of Ontario Hydro's program to further assess cycle selection and define development needs is given. (auth)

  7. Sarcocystis neurona infections in sea otter (Enhydra lutris): evidence for natural infections with sarcocysts and transmission of infection to opossums (Didelphis virginiana).

    Science.gov (United States)

    Dubey, J R; Rosypal, A C; Rosenthal, B M; Thomas, N J; Lindsay, D S; Stanek, J F; Reed, S M; Saville, W J

    2001-12-01

    Although Sarcocystis neurona has been identified in an array of terrestrial vertebrates, recent recognition of its capacity to infect marine mammals was unexpected. Here, sarcocysts from 2 naturally infected sea otters (Enhydra lutris) were characterized biologically, ultrastructurally, and genetically. DNA was extracted from frozen muscle of the first of these sea otters and was characterized as S. neurona by polymerase chain reation (PCR) amplification followed by restriction fragment length polymorphism analysis and sequencing. Sarcocysts from sea otter no. 1 were up to 350 microm long, and the villar protrusions on the sarcocyst wall were up to 1.3 microm long and up to 0.25 microm wide. The villar protrusions were tapered towards the villar tip. Ultrastructurally, sarcocysts were similar to S. neurona sarcocysts from the muscles of cats experimentally infected with S. neurona sporocysts. Skeletal muscles from a second sea otter failed to support PCR amplification of markers considered diagnostic for S. neurona but did induce the shedding of sporocysts when fed to a laboratory-raised opossum (Didelphis virginiana). Such sporocysts were subsequently fed to knockout mice for the interferon-gamma gene, resulting in infections with an agent identified as S. neurona on the basis of immunohistochemistry, serum antibodies, and diagnostic sequence detection. Thus, sea otters exposed to S. neurona may support the development of mature sarcocysts that are infectious to competent definitive hosts.

  8. Sarcocystis neurona infections in sea otter (Enhydra lutris): evidence for natural infections with sarcocysts and transmission of infection to opossums (Didelphis virginiana)

    Science.gov (United States)

    Dubey, J.P.; Rosypal, A.C.; Rosenthal, B.M.; Thomas, N.J.; Lindsay, D.S.; Stanek, J.F.; Reed, S.M.; Saville, W.J.A.

    2001-01-01

    Although Sarcocystis neurona has been identified in an array of terrestrial vertebrates, recent recognition of its capacity to infect marine mammals was unexpected. Here, sarcocysts from 2 naturally infected sea otters (Enhydra lutris) were characterized biologically, ultrastructurally, and genetically. DNA was extracted from frozen muscle of the first of these sea otters and was characterized as S. neurona by polymerase chain reation (PCR) amplification followed by restriction fragment length polymorphism analysis and sequencing. Sarcocysts from sea otter no. 1 were up to 350 I?m long, and the villar protrusions on the sarcocyst wall were up to 1.3 I?m long and up to 0.25 I?m wide. The villar protrusions were tapered towards the villar tip. Ultrastructurally, sarcocysts were similar to S. neurona sarcocysts from the muscles of cats experimentally infected with S. neurona sporocysts. Skeletal muscles from a second sea otter failed to support PCR amplification of markers considered diagnostic for S. neurona but did induce the shedding of sporocysts when fed to a laboratory-raised opossum (Didelphis virginiana). Such sporocysts were subsequently fed to knockout mice for the interferon-gamma gene, resulting in infections with an agent identified as S. neurona on the basis of immunohistochemistry, serum antibodies, and diagnostic sequence detection. Thus, sea otters exposed to S. neurona may support the development of mature sarcocysts that are infectious to competent definitive hosts.

  9. The influence of the internal microbiome on the materials used for construction of the transmission natural gas pipelines in the Lodz Province

    Science.gov (United States)

    Staniszewska, Agnieszka; Jastrzębska, Magdalena; Ziemiński, Krzysztof

    2017-10-01

    This paper presents investigation results of the influence of gas microbes on the biocorrosion rate of the materials used for gas pipelines construction in the Lodz Province. Samples of two types of carbon steel and cast iron were stored in the laboratory pipeline model reflecting the real conditions of working natural gas pipelines were. In the next step the influence of cathodic protection with parameters recommended for protection of underground structures was tested. Analyses of biological corrosion products generated on the test surface were carried out using a scanning electron microscope with an X-ray analyzer. The level of ATP was measured to confirm presence of the adsorbed microorganisms on the observed structures. Corrosion rates were determined by gravimetric methods. In the course of the study it was revealed that the rate of biocorrosion of steel is lower than that for cast iron. Our results also proved that the weight corrosion rate depends on the number of adhered microorganisms. In addition, it has been found that application of the carbon steel cathodic protection decreases its weight corrosion rate. The information obtained will help to increase the knowledge on the rate of biological corrosion causing losses/pits inside gas pipline.

  10. The influence of the internal microbiome on the materials used for construction of the transmission natural gas pipelines in the Lodz Province

    Directory of Open Access Journals (Sweden)

    Staniszewska Agnieszka

    2017-01-01

    Full Text Available This paper presents investigation results of the influence of gas microbes on the biocorrosion rate of the materials used for gas pipelines construction in the Lodz Province. Samples of two types of carbon steel and cast iron were stored in the laboratory pipeline model reflecting the real conditions of working natural gas pipelines were. In the next step the influence of cathodic protection with parameters recommended for protection of underground structures was tested. Analyses of biological corrosion products generated on the test surface were carried out using a scanning electron microscope with an X-ray analyzer. The level of ATP was measured to confirm presence of the adsorbed microorganisms on the observed structures. Corrosion rates were determined by gravimetric methods. In the course of the study it was revealed that the rate of biocorrosion of steel is lower than that for cast iron. Our results also proved that the weight corrosion rate depends on the number of adhered microorganisms. In addition, it has been found that application of the carbon steel cathodic protection decreases its weight corrosion rate. The information obtained will help to increase the knowledge on the rate of biological corrosion causing losses/pits inside gas pipline.

  11. The evolution of transmission mode

    Science.gov (United States)

    Forbes, Mark R.; Hauffe, Heidi C.; Kallio, Eva R.; Okamura, Beth; Sait, Steven M.

    2017-01-01

    This article reviews research on the evolutionary mechanisms leading to different transmission modes. Such modes are often under genetic control of the host or the pathogen, and often in conflict with each other via trade-offs. Transmission modes may vary among pathogen strains and among host populations. Evolutionary changes in transmission mode have been inferred through experimental and phylogenetic studies, including changes in transmission associated with host shifts and with evolution of the unusually complex life cycles of many parasites. Understanding the forces that determine the evolution of particular transmission modes presents a fascinating medley of problems for which there is a lack of good data and often a lack of conceptual understanding or appropriate methodologies. Our best information comes from studies that have been focused on the vertical versus horizontal transmission dichotomy. With other kinds of transitions, theoretical approaches combining epidemiology and population genetics are providing guidelines for determining when and how rapidly new transmission modes may evolve, but these are still in need of empirical investigation and application to particular cases. Obtaining such knowledge is a matter of urgency in relation to extant disease threats. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289251

  12. Transcending Transmission

    DEFF Research Database (Denmark)

    Schoeneborn, Dennis; Trittin, Hannah

    2013-01-01

    Purpose – Extant research on corporate social responsibility (CSR) communication primarily relies on a transmission model of communication that treats organizations and communication as distinct phenomena. This approach has been criticized for neglecting the formative role of communication...... in the emergence of organizations. This paper seeks to propose to reconceptualize CSR communication by drawing on the “communication constitutes organizations” (CCO) perspective. Design/methodology/approach – This is a conceptual paper that explores the implications of switching from an instrumental...... to a constitutive notion of communication. Findings – The study brings forth four main findings: from the CCO view, organizations are constituted by several, partly dissonant, and potentially contradictory communicative practices. From that viewpoint, the potential impact of CSR communication becomes a matter...

  13. Development of Natural Gas Fired Combined Cycle Plant for Tri-Generation of Power, Cooling and Clean Water Using Waste Heat Recovery: Techno-Economic Analysis

    Directory of Open Access Journals (Sweden)

    Gowtham Mohan

    2014-10-01

    Full Text Available Tri-generation is one of the most efficient ways for maximizing the utilization of available energy. Utilization of waste heat (flue gases liberated by the Al-Hamra gas turbine power plant is analyzed in this research work for simultaneous production of: (a electricity by combining steam rankine cycle using heat recovery steam generator (HRSG; (b clean water by air gap membrane distillation (AGMD plant; and (c cooling by single stage vapor absorption chiller (VAC. The flue gases liberated from the gas turbine power cycle is the prime source of energy for the tri-generation system. The heat recovered from condenser of steam cycle and excess heat available at the flue gases are utilized to drive cooling and desalination cycles which are optimized based on the cooling energy demands of the villas. Economic and environmental benefits of the tri-generation system in terms of cost savings and reduction in carbon emissions were analyzed. Energy efficiency of about 82%–85% is achieved by the tri-generation system compared to 50%–52% for combined cycles. Normalized carbon dioxide emission per MW·h is reduced by 51.5% by implementation of waste heat recovery tri-generation system. The tri-generation system has a payback period of 1.38 years with cumulative net present value of $66 million over the project life time.

  14. Effects of the Natural and Artificial Menstrual Cycle on the Production of Osteoprotegerin and the Bone Resorptive Cytokines IL-1b and IL-6

    DEFF Research Database (Denmark)

    Abrahamsen, B.; Stilgren, L.S.; Rettmer, E.

    2003-01-01

    ) within the menstrual cycle prevent the increase in bone remodelling, which would otherwise have been the result of the luteal increase in the capacity for producing resorptive cytokines. The study population consisted of healthy female volunteers: premenopausal women (n = 11, mean age 39.4 y +/- 6.......1) without cycle irregularities. Postmenopausal women (n = 11, mean age 56.8 y +/- 3.6) receiving cyclic HRT (estradiol and noretisterone acetate). Luteal and follicular phase blood samples were diluted and cultured for 24 hours with and without lipopolysaccharide (LPS). The supernatant was assayed for IL-1...

  15. Effects of ultraviolet irradiation on the cell cycle in normal and UV-sensitive cell lines with reference to the nature of the defect in xeroderma pigmentosum variant

    International Nuclear Information System (INIS)

    Imray, P.; Mangan, T.; Saul, A.; Kidson, C.

    1983-01-01

    Analysis of the distribution of cells through the phases of the cell cycle by DNA flow cytofluorimetry has been utilized to investigate the effects of ultraviolet (UV) irradiation on cell-cycle progression in normal and UV-sensitive lymphoblastoid cell lines. In time-course studies only slight perturbation of DNA distribution was seen in normal cells, or UV-sensitive familial melanoma (FM) lines in the 48 h following irradiation. Xeroderma pigmentosum (XPA) excision-deficient cells showed a large increase in the proportion of cells in S phase 16-40 h post-irradiation. XP variant (XPV) cells were blocked in G 1 and S phases with the complete absence of cells with G 2 DNA content 16-28 h after irradiation. By 48 h post-irradiation the DNA distribution of XPA and XPV cells had returned to that of an unirradiated control. When colcemid was added to the cultures immediately after irradiation to prevent mitotic cells dividing and re-entering the cell cycle, progression through the first cycle after irradiation was followed. UV irradiation did not affect the rate of movement of cells out of G 1 into S phase in normal, FM or XPA cells. The proportion of cells in S phase was increased in UV-irradiated cultures in these cell types and the number of cells entering the G 2 +M compartment was reduced. (orig./AJ)

  16. Quantifying the environmental impact of an integrated human/industrial-natural system using life cycle assessment; a case study on a forest and wood processing chain.

    Science.gov (United States)

    Schaubroeck, Thomas; Alvarenga, Rodrigo A F; Verheyen, Kris; Muys, Bart; Dewulf, Jo

    2013-01-01

    Life Cycle Assessment (LCA) is a tool to assess the environmental sustainability of a product; it quantifies the environmental impact of a product's life cycle. In conventional LCAs, the boundaries of a product's life cycle are limited to the human/industrial system, the technosphere. Ecosystems, which provide resources to and take up emissions from the technosphere, are not included in those boundaries. However, similar to the technosphere, ecosystems also have an impact on their (surrounding) environment through their resource usage (e.g., nutrients) and emissions (e.g., CH4). We therefore propose a LCA framework to assess the impact of integrated Techno-Ecological Systems (TES), comprising relevant ecosystems and the technosphere. In our framework, ecosystems are accounted for in the same manner as technosphere compartments. Also, the remediating effect of uptake of pollutants, an ecosystem service, is considered. A case study was performed on a TES of sawn timber production encompassing wood growth in an intensively managed forest ecosystem and further industrial processing. Results show that the managed forest accounted for almost all resource usage and biodiversity loss through land occupation but also for a remediating effect on human health, mostly via capture of airborne fine particles. These findings illustrate the potential relevance of including ecosystems in the product's life cycle of a LCA, though further research is needed to better quantify the environmental impact of TES.

  17. The assessment of the influence of different natural conditions on the particular processes of the hydrological cycle within a river basin

    Czech Academy of Sciences Publication Activity Database

    Šípek, Václav; Němečková, Soňa

    2011-01-01

    Roč. 13, - (2011), s. 6904 ISSN 1607-7962. [European Geosciences Union General Assembly 2011. 03.04.2011-08.04.2011, Vienna] R&D Projects: GA AV ČR IAA300600901 Institutional research plan: CEZ:AV0Z20600510 Keywords : hydrological modelling * hydrological cycle * SWIM model Subject RIV: DA - Hydrology ; Limnology

  18. Development of Natural Gas Fired Combined Cycle Plant for Tri-Generation of Power, Cooling and Clean Water Using Waste Heat Recovery: Techno-Economic Analysis

    OpenAIRE

    Mohan, Gowtham; Dahal, Sujata; Kumar, Uday; Martin, Andrew; Kayal, Hamid

    2014-01-01

    Tri-generation is one of the most efficient ways for maximizing the utilization of available energy. Utilization of waste heat (flue gases) liberated by the Al-Hamra gas turbine power plant is analyzed in this research work for simultaneous production of: (a) electricity by combining steam rankine cycle using heat recovery steam generator (HRSG); (b) clean water by air gap membrane distillation (AGMD) plant; and (c) cooling by single stage vapor absorption chiller (VAC). The flue gases liber...

  19. Report on studies on closed cycle MHD power generation; Closed cycle MHD hatsuden kento hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-04-01

    Summarized herein are results of the studies on closed cycle MHD (CCMHD) power generation by the study committee. The studied system is based on the MHD gas turbine combined Brayton cycle of about 500,000 kW in output power, firing natural gas as the fuel, and the conceptual design works therefor are completed. The major findings are: the overall plant efficiency: 54.2% at the power transmission side, plot area required per unit power output: 0.04 m{sup 2}/KW, unit construction cost: 251,000 yen/KW, and unit power generation cost: 10.2 yen/KWh. This system will be more operable than the gas turbine combined cycle with steam system, because start-up time, output change rate, optimum load and so on are constrained not on the power generator side but on the gas turbine side. The expected environmental effects include the exhaust gas NOX concentration being equivalent with that associated with the conventional power generator of 2-stage combustion system, quantity of combustion gases to be treated being approximately 40% of that associated with the gas turbine combined cycle, and reduced CO2 gas emissions, resulting from enhanced power generation efficiency. It is expected that the CCMHD system can exhibit higher efficiency than the high-temperature gas turbine combined cycle system. (NEDO)

  20. Investigation of Transmission Warming Technologies at Various Ambient Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jehlik, Forrest; Iliev, Simeon; Wood, Eric; Gonder, Jeff

    2017-03-28

    This work details two approaches for evaluating transmission warming technology: experimental dynamometer testing and development of a simplified transmission efficiency model to quantify effects under varied real world ambient and driving conditions. Two vehicles were used for this investigation: a 2013 Ford Taurus and a 2011 Ford Fusion. The Taurus included a production transmission warming system and was tested over hot and cold ambient temperatures with the transmission warming system enabled and disabled. A robot driver was used to minimize driver variability and increase repeatability. Additionally the Fusion was tested cold and with the transmission pre-heated prior to completing the test cycles. These data were used to develop a simplified thermally responsive transmission model to estimate effects of transmission warming in real world conditions. For the Taurus, the fuel consumption variability within one standard deviation was shown to be under 0.5% for eight repeat Urban Dynamometer Driving Cycles (UDDS). These results were valid with the transmission warming system active or passive. Using the transmission warming system under 22 degrees C ambient temperature, fuel consumption reduction was shown to be 1.4%. For the Fusion, pre-warming the transmission reduced fuel consumption 2.5% for an urban drive cycle at -7 degrees C ambient temperature, with 1.5% of the 2.5% gain associated with the transmission, while consumption for the US06 test was shown to be reduced by 7% with 5.5% of the 7% gain associated with the transmission. It was found that engine warming due to conduction between the pre-heated transmission and the engine resulted in the remainder of the benefit. For +22 degrees C ambient tests, the pre-heated transmission was shown to reduce fuel consumption approximately 1% on an urban cycle, while no benefit was seen for the US06 cycle. The simplified modeling results showed gains in efficiency ranging from 0-1.5% depending on the ambient

  1. Sulfur cycle

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.

    Microbes, especially bacteria, play an important role in oxidative and reductive cycle of sulfur. The oxidative part of the cycle is mediated by photosynthetic bacteria in the presence of light energy and chemosynthetic forms in the absence of light...

  2. Transmission and capacity pricing and constraints

    International Nuclear Information System (INIS)

    Fusco, M.

    1999-01-01

    A series of overhead viewgraphs accompanied this presentation which discussed the following issues regarding the North American electric power industry: (1) capacity pricing transmission constraints, (2) nature of transmission constraints, (3) consequences of transmission constraints, and (4) prices as market evidence. Some solutions suggested for pricing constraints included the development of contingent contracts, back-up power in supply regions, and new line capacity construction. 8 tabs., 20 figs

  3. Survey of Transmission Cost Allocation Methodologies for Regional Transmission Organizations

    Energy Technology Data Exchange (ETDEWEB)

    Fink, S.; Porter, K.; Mudd, C.; Rogers, J.

    2011-02-01

    The report presents transmission cost allocation methodologies for reliability transmission projects, generation interconnection, and economic transmission projects for all Regional Transmission Organizations.

  4. SIMULATION OF FORWARD AND BACKWARD WAVES EVOLUTION OF FEW-CYCLE PULSES PROPAGATING IN AN OPTICAL WAVEGUIDE WITH DISPERSION AND CUBIC NONLINEARITY OF ELECTRONIC AND ELECTRONIC-VIBRATION NATURE

    Directory of Open Access Journals (Sweden)

    L. S. Konev

    2015-09-01

    Full Text Available Numerical method for calculation of forward and backward waves of intense few-cycle laser pulses propagating in an optical waveguide with dispersion and cubic nonlinearity of electronic and electronic-vibration nature is described. Simulations made with the implemented algorithm show that accounting for Raman nonlinearity does not lead to qualitative changes in behavior of the backward wave. Speaking about quantitative changes, the increase of efficiency of energy transfer from the forward wave to the backward wave is observed. Presented method can be also used to simulate interaction of counterpropagating pulses.

  5. Natural resources as an area of protection in LCA - outcomes of the discussion by the working group on resources within the UNEP-SETAC Life Cycle Initiative

    DEFF Research Database (Denmark)

    Sonderegger, T.; Fantke, Peter; Dewulf, J.

    2016-01-01

    , water, land/soil, biotic resources like wild plants and animals). Definitions and categorizations of natural resources differ and there is no agreement on what methods should be considered midpoint or endpoint methods because there is no agreement (at midpoint and endpoint) on what impact should...

  6. The study of the energetic performance in test cycles

    Science.gov (United States)

    Rentea, Cristian; Tuca, Alexandra; Oprean, Mircea; Marius, Bataus

    2017-10-01

    One of the most important subsystems of modern passenger cars is the transmission. This paper aims to investigate the global performances of a modern transmission in different test cycles including the newly introduced WLTC (Worldwide Harmonized Light Vehicles Test Cycle). The study is done using a complex model developed in a performant simulation environment. Transmission efficiency calculation is emphasized, the efficiency being considered variable depending on engine torque, engine speed and gear ratio. The main important parameters (vehicle speed fluctuation, overall transmission efficiency, fuel consumption ratio) needed to compare test cycles and the transmissions performance are determined.

  7. Annual cycle of the microzooplankton communities in the waters surrounding the Palm Island Nature Reserve (north Lebanon, with special attention to tintinnids

    Directory of Open Access Journals (Sweden)

    M. ABBOUD-ABI SAAB

    2002-12-01

    Full Text Available The distribution, abundance and annual cycle of microzooplankton communities have been studied monthly at five sampling stations in the north Lebanon, covering both neritic and oceanic waters in the vicinity of small islands situated 5 km offshore.In general, the density of microprotozoans, except for ciliates, increased from the coastal towards the offshore area, with stations situated near the islands being similar to the offshore rather than to the coastal ones. The microprotozoan species showed their highest numbers in late autumn and early winter. Foraminifera abundance ranged from 20 to 3390 inds.m -3 (mean= 549 whereas Acantharia abundance was highest in spring and ranged from 0 to 2608 inds.m -3 (mean 259. The Polycistina had their highest numbers in late winter, which ranged from 0 to 6024 inds.m -3 (mean= 740. The Heliozoa were abundant in late autumn with numbers ranging from 0 to 5165 inds.m -3 (mean= 555. The annual cycle of Tintinnids at all the stations was bimodal with a principal peak in October-November and another one in May, while minimum numbers were recorded in August-September. A succession of populations was observed all year round with a density ranging between 344 and 38986 inds.m -3 (mean = 10878. Ninety different species of Tintinnids were recorded. The diversity index varied between 0.19 and 4.15. It was concluded that there was a large-scale gradient in seasonal diversity which could be related to the annual average sea surface temperature and to the development of the vertical thermic structure.

  8. The life cycle of Babesia bovis and Babesia bigemina in ticks and cattle in South Africa

    OpenAIRE

    2015-01-01

    Ph.D. Bovine babesiosis, or redwater, is at present known to be caused by Babesia bigemina and Babesia bovis in the Republic of South Africa. Until recently, however, the only information on the natural transmission of these parasites in the country was based on observations made during the early part of this century and information on the developmental cycle of the parasites in their vectors was superficial or nonexistent ...

  9. Uncertainties in the Forecasted Performance of Sediment Diversions Associated with Differences Between "Optimized" Diversion Design Criteria and the Natural Crevasse-Splay Sub-Delta Life-Cycle

    Science.gov (United States)

    Brown, G.

    2017-12-01

    Sediment diversions have been proposed as a crucial component of the restoration of Coastal Louisiana. They are generally characterized as a means of creating land by mimicking natural crevasse-splay sub-delta processes. However, the criteria that are often promoted to optimize the performance of these diversions (i.e. large, sand-rich diversions into existing, degraded wetlands) are at odds with the natural processes that govern the development of crevasse-splay sub-deltas (typically sand-lean or sand-neutral diversions into open water). This is due in large part to the fact that these optimization criteria have been developed in the absence of consideration for the natural constraints associated with fundamental hydraulics: specifically, the conservation of mechanical energy. Although the implementation of the aforementioned optimization criteria have the potential to greatly increase the land-building capacity of a given diversion, the concomitant widespread inundation of the existing wetlands (an unavoidable consequence of diverting into a shallow, vegetated embayment), and the resultant stresses on existing wetland vegetation, have the potential to dramatically accelerate the loss of these existing wetlands. Hence, there are inherent uncertainties in the forecasted performance of sediment diversions that are designed according to the criteria mentioned above. This talk details the reasons for these uncertainties, using analytic and numerical model results, together with evidence from field observations and experiments. The likelihood that, in the foreseeable future, these uncertainties can be reduced, or even rationally bounded, is discussed.

  10. The determination of resistance of marble to thermal and moisture cycles: relevance and limits of the recent European natural stone standard

    Science.gov (United States)

    Bellopede, Rossana; Castelletto, Eleonora; Marini, Paola; Zichella, Lorena

    2015-04-01

    The recent European standard EN 16306:2013 specifies laboratory methodology on the determination of the resistance to thermal and moisture cycling of marble for cladding of building façades. In particular measurements of bowing and flexural strength should be performed before and at the end of the ageing cycles. Bowing is measured on specimens of dimension 30*100*400mm exposed to moisture from beneath and heating (gradually till 80°C) on the upper face. The flexural strength should be measured both on reference and on exposed specimens in order to assess the variation of mechanical properties. Additional non-destructive tests are foreseen but are not compulsory for the standard. Moreover, the Annex A of the EN 16306, contains a guidance of the limit values that could be useful for the building planner for façade panels dimensioning. Different varieties of marble (two from Italy, one from Greece and three from Portugal) have been tested by means of this laboratory ageing test. Non-destructive tests such as the measurements of Ultrasonic Pulse Velocity (UPV), porosity, and water absorption have been executed together with the conventional flexural strength test. Image analysis on thin sections soaked with methylene blue have been analysed to further investigate the correlation between porosity and tendency to bowing. Base on the results obtained, some consideration on the decrease of mechanical resistance and the bowing in relation to the variety of marble tested and the limit values indicated the Annex A of EN 16306 can be drawn. Besides, from the data analysed a deepened discussion has been made. It is known that bowing and rapid strength loss occur in some varieties of marble when used as exterior cladding but further considerations can be made: bowing and flexural strength are correlate and in which way? Often the bowing is related to the decrease of flexural strength but it happens that there is a decrease in the mechanical resistance of the stone also

  11. On the nature of anomalies in temperature dependence of the OKh18N1OT steel yield strength after thermal cycling in the low temperature range

    International Nuclear Information System (INIS)

    Medvedev, E.M.; Lavrent'ev, F.F.; Kurmanova, T.N.

    1978-01-01

    Investigated were structural transformations in 0Kh18N10T steel as a result of heating and cooling and of deformation within the range of temperatures between 300 and 77 K, the quantity relationships between the said transformations and the variation of the yield limit with the temperature. The studies were conducted by metallography and mechanical test methods. It was shown that an increase in the number of heating and cooling cycles correlates with a loss in strength of the steel while deformation at 77 K. This anomaly in the temperature relationship of the yield limit is related to the appearance in the course of deformation of α-martensite with a BCC lattice. Deformation at 300 K increases the amount ea of epsilon-martensite, a decrses the effectve size of grain and, in consequence, increases the yield limit. The relationship between the yield limit and the grain size at the temperature of 300 K is described adequately by the Hall-Petch equation

  12. Essays on electricity transmission investment and financial transmission rights

    Science.gov (United States)

    Shang, Wenzhuo

    The U.S. electric power industry has been going through fundamental restructuring and realignment since the 1990's. Many issues and problems have emerged during the transition, and both economists and engineers have been looking for the solutions fervently. In this dissertation, which consists primarily of three essays, we apply economics theory and techniques to the power industry and address two related issues, transmission investment and financial transmission rights (FTRs). The first essay takes the decentralized perspective and investigates the efficiency attribute of market-based transmission investment under perfect competition. We clarify, for the first time, the nature of the externality created by loop flows that causes transmission investment to be inefficient. Our findings have important implications for better understanding of transmission market design and creating incentives for efficient transmission investment. In the second essay, we define several rules for allocating transmission investment cost within the framework of cooperative game theory. These rules provide fair, stable or efficient cost allocations in theory and are good benchmarks against which the allocation mechanism in practice can be compared and improved upon. In the last essay, we make exploratory efforts in analyzing and assessing empirically the performance of the Midwest independent system operator (MISO) FTR auction market. We reveal some stylized facts about this young market and find that it is not efficient under the risk-neutrality assumption. We also point out and correct the drawbacks in previous related work and suggest about more complete empirical work in future. In all, this dissertation makes both theoretic and empirical analysis of the two hot issues related to the power industry and comes up with findings that have important implications for the development of this industry.

  13. Riding the cycle

    Energy Technology Data Exchange (ETDEWEB)

    Webster, G. [Canadian Association of Petroleum Producers, Calgary, AB (Canada)

    2001-07-01

    The current state of the Canadian oil and natural gas industry is reviewed as part of a discussion of economic cycles focusing in particular on the most recent cycle and the impact it has had on the industry. The review of the state of the industry includes discussion of production, exports, commodity prices, the stimulating effect of price increases on the number of oil and natural gas wells drilled, drilling rig operating days. Also discussed are the effect of foreign exchange rates, capital spending, industry financial performance in terms of return on capital employed, the impact of oil and gas prices on Alberta provincial revenues, estimates of Canada's ultimate crude oil and natural gas resources potential, pipelines and pipeline proposals for northern gas, and projection of crude oil and natural gas production in Canada to 2010.

  14. Riding the cycle

    International Nuclear Information System (INIS)

    Webster, G.

    2001-01-01

    The current state of the Canadian oil and natural gas industry is reviewed as part of a discussion of economic cycles focusing in particular on the most recent cycle and the impact it has had on the industry. The review of the state of the industry includes discussion of production, exports, commodity prices, the stimulating effect of price increases on the number of oil and natural gas wells drilled, drilling rig operating days. Also discussed are the effect of foreign exchange rates, capital spending, industry financial performance in terms of return on capital employed, the impact of oil and gas prices on Alberta provincial revenues, estimates of Canada's ultimate crude oil and natural gas resources potential, pipelines and pipeline proposals for northern gas, and projection of crude oil and natural gas production in Canada to 2010

  15. Exergy analysis of a hydrogen fired combined cycle with natural gas reforming and membrane assisted shift reactors for CO2 capture

    International Nuclear Information System (INIS)

    Atsonios, K.; Panopoulos, K.D.; Doukelis, A.; Koumanakos, A.; Kakaras, Em.

    2012-01-01

    Highlights: ► Exergy analysis of NGCC with CCS. ► WGS-MR: exergetically efficient technology for CCS, less than 2% total exergy losses. ► 10% of total exergy dissipation in the ATR. ► Optimization of ATR operation and CO 2 stream treatment. - Abstract: Hydrogen production from fossil fuels together with carbon capture has been suggested as a means of providing a carbon free power. The paper presents a comparative exergetic analysis performed on the hydrogen production from natural gas with several combinations of reactor systems: (a) oxy or air fired autothermal reforming with subsequent water gas shift reactor and (b) membrane reactor assisted with shift catalysts. The influence of reactor temperature and pressure as well as operating parameter steam-to-carbon ratio, is also studied exergetically. The results indicate optimal power plant configurations with CO 2 capture, or hydrogen delivery for industrial applications.

  16. Contaminants from Cretaceous Black Shale Part 1: Natural weathering processes controlling contaminant cycling in Mancos Shale, southwestern United States, with emphasis on salinity and selenium

    Science.gov (United States)

    Tuttle, Michele L.W.; Fahy, Juli W.; Elliott, John G.; Grauch, Richard I.; Stillings, Lisa L.

    2013-01-01

    Soils derived from black shale can accumulate high concentrations of elements of environmental concern, especially in regions with semiarid to arid climates. One such region is the Colorado River basin in the southwestern United States where contaminants pose a threat to agriculture, municipal water supplies, endangered aquatic species, and water-quality commitments to Mexico. Exposures of Cretaceous Mancos Shale (MS) in the upper basin are a major contributor of salinity and selenium in the Colorado River. Here, we examine the roles of geology, climate, and alluviation on contaminant cycling (emphasis on salinity and Se) during weathering of MS in a Colorado River tributary watershed. Stage I (incipient weathering) began perhaps as long ago as 20 ka when lowering of groundwater resulted in oxidation of pyrite and organic matter. This process formed gypsum and soluble organic matter that persist in the unsaturated, weathered shale today. Enrichment of Se observed in laterally persistent ferric oxide layers likely is due to selenite adsorption onto the oxides that formed during fluctuating redox conditions at the water table. Stage II weathering (pedogenesis) is marked by a significant decrease in bulk density and increase in porosity as shale disaggregates to soil. Rainfall dissolves calcite and thenardite (Na2SO4) at the surface, infiltrates to about 1 m, and precipitates gypsum during evaporation. Gypsum formation (estimated 390 kg m−2) enriches soil moisture in Na and residual SO4. Transpiration of this moisture to the surface or exposure of subsurface soil (slumping) produces more thenardite. Most Se remains in the soil as selenite adsorbed to ferric oxides, however, some oxidizes to selenate and, during wetter conditions is transported with soil moisture to depths below 3 m. Coupled with little rainfall, relatively insoluble gypsum, and the translocation of soluble Se downward, MS landscapes will be a significant nonpoint source of salinity and Se to the

  17. Influence of the natural dyes bixin and curcumin in the shelf life of eggs from laying hens in the second production cycle - doi: 10.4025/actascianimsci.v34i2.12096

    Directory of Open Access Journals (Sweden)

    Érika Salgado Politi Braga Saldanha

    2012-03-01

    Full Text Available This study was developed to evaluate the effect of adding natural pigments on the storage of eggs from laying hens in the second production cycle submitted to diets based on corn and low-tannin sorghum. A total of 160 eggs from Hy-Line Brown laying hens at 90 - weeks old after forced molting were used. The study evaluated the isolated effect and the interaction of two factors: the inclusion of natural pigments (control diet - 50% low-tannin sorghum replacing the corn; RC - 2% powdered dry turmeric rhizome; PU - 2% dry annatto powder; RCPU - 1% turmeric rhizome + 1% dry annatto powder combined with the storage period (0, 3, 7, 14 and 21 days. The studied variables were: specific gravity, percentages of yolk, albumen and shell in relation to the egg weight, and yolk color. Yolk color was more intense with increasing percentage of annatto. The inclusion of 2% annatto powder promotes and maintains an adequate pigmentation of egg yolk when stored for up to 21 days. Regardless of natural pigment supplementation, the egg quality decreases as storage time increases. 

  18. The identification of two Trypanosoma cruzi I genotypes from domestic and sylvatic transmission cycles in Colombia based on a single polymerase chain reaction amplification of the spliced-leader intergenic region

    Directory of Open Access Journals (Sweden)

    Lina Marcela Villa

    2013-11-01

    Full Text Available A single polymerase chain reaction (PCR reaction targeting the spliced-leader intergenic region of Trypanosoma cruzi I was standardised by amplifying a 231 bp fragment in domestic (TcIDOM strains or clones and 450 and 550 bp fragments in sylvatic strains or clones. This reaction was validated using 44 blind coded samples and 184 non-coded T. cruzi I clones isolated from sylvatic triatomines and the correspondence between the amplified fragments and their domestic or sylvatic origin was determined. Six of the nine strains isolated from acute cases suspected of oral infection had the sylvatic T. cruzi I profile. These results confirmed that the sylvatic T. cruzi I genotype is linked to cases of oral Chagas disease in Colombia. We therefore propose the use of this novel PCR reaction in strains or clones previously characterised as T. cruzi I to distinguish TcIDOMfrom sylvatic genotypes in studies of transmission dynamics, including the verification of population selection within hosts or detection of the frequency of mixed infections by both T. cruzi I genotypes in Colombia.

  19. Seasonal changes in hepatocytic lipid droplets, glycogen deposits, and rough endoplasmic reticulum along the natural breeding cycle of female ohrid trout (Salmo letnica Kar.)-A semiquantitative ultrastructural study.

    Science.gov (United States)

    Jordanova, Maja; Rebok, Katerina; Malhão, Fernanda; Rocha, Maria J; Rocha, Eduardo

    2016-08-01

    This study on wild female Ohrid trout was primarily designed to provide a general overview of the breeding cycle influence upon selected aspects of hepatocytes. According with a semiquantitatively evaluation, some of these cell's structural compartments change during the breeding cycle. Structural modifications were disclosed in the relative occurrence of lipid, glycogen, and RER content during breeding cycle. The relative amount of lipid deposits in the hepatocytes was much greater in previtellogenesis, and decreased postspawning. So, while the seasonal changes in RER were positively related with the ovary maturation status, those of the lipid droplets followed an opposite trend. The hepatocytic glycogen occurred rarely, mainly in late-vitellogenesis and spawning, suggesting that in this species such kind of energy storage is comparatively unimportant. Lipid accumulation and later usage is, probably, the relevant biochemical pathway for Ohrid trout in the wild. While glycogen and RER contents were positively correlated with the gonadosomatic index, lipids were negatively correlated. Additionally, glycogen inclusions were positively correlated with the plasma estradiol levels. When comparing seasonal patterns from wild Ohrid trout with those from well-studied rainbow and brown trout (specimens studied were from aquaculture), there are contradicting results as to lipid and glycogen reserves, and also as to RER loads. The differences among the mentioned trout can result from intrinsic interspecies differences or may be associated with natural feeding conditions versus feeding with commercially prepared diets, or other factors. This study offers new data useful as standard to access liver pathology in wild and aquacultured Ohrid trout. Microsc. Res. Tech. 79:700-706, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Space power transmission

    Energy Technology Data Exchange (ETDEWEB)

    Kuribayashi, Shizuma [Mitsubishi Heavy Industries, Ltd., Tokyo, (Japan)

    1989-10-05

    There being a conception to utilize solar energy by use of a space power station (SPS), a method to bring that universal grace to mankind is wireless energy transmission. The wireless energy transmission is regarded to be microwave transmission or laser beam transmission. The microwave transmission is to transmit 2.45GHz band microwave from the SPS to a receiving station on the ground to meet power demand on earth. The microwave, as small in attenuation in atmosphere and resistant against rain and cloud, is made candidate and, however, problematic in influence on organism, necessary large area of receiving antenna and many other points to be studied. While the laser transmission, as more convergent of beam than the microwave transmission, is advantageous with enabling the receiving area to be small and, however, disadvantageous with being not resistant against dust, rain and cloud, if used for the energy transmission between the space and earth. 2 refs., 2 figs.

  1. Transmission on Balance 2006

    International Nuclear Information System (INIS)

    2007-02-01

    Every year he Dutch Transmission System Operator (TSO) TenneT issues the title publication 'Transmission on Balance'. This report provides information about the main technical operating results in the past year.

  2. Glacial cycles

    DEFF Research Database (Denmark)

    Kaufmann, R. K.; Juselius, Katarina

    We use a statistical model, the cointegrated vector autoregressive model, to assess the degree to which variations in Earth's orbit and endogenous climate dynamics can be used to simulate glacial cycles during the late Quaternary (390 kyr-present). To do so, we estimate models of varying complexity...... and compare the accuracy of their in-sample simulations. Results indicate that strong statistical associations between endogenous climate variables are not enough for statistical models to reproduce glacial cycles. Rather, changes in solar insolation associated with changes in Earth's orbit are needed...... to simulate glacial cycles accurately. Also, results suggest that non-linear 10 dynamics, threshold effects, and/or free oscillations may not play an overriding role in glacial cycles....

  3. Fuel cycles

    International Nuclear Information System (INIS)

    Hawley, N.J.

    1983-05-01

    AECL publications, from the open literature, on fuels and fuel cycles used in CANDU reactors are listed in this bibliography. The accompanying index is by subject. The bibliography will be brought up to date periodically

  4. The automotive transmission book

    CERN Document Server

    Fischer, Robert; Jürgens, Gunter; Najork, Rolf; Pollak, Burkhard

    2015-01-01

    This book presents essential information on systems and interactions in automotive transmission technology and outlines the methodologies used to analyze and develop transmission concepts and designs. Functions of and interactions between components and subassemblies of transmissions are introduced, providing a basis for designing transmission systems and for determining their potentials and properties in vehicle-specific applications: passenger cars, trucks, buses, tractors, and motorcycles. With these fundamentals the presentation provides universal resources for both state-of-the-art and future transmission technologies, including systems for electric and hybrid electric vehicles.

  5. The Chagas disease domestic transmission cycle in Guatemala: Parasite-vector switches and lack of mitochondrial co-diversification between Triatoma dimidiata and Trypanosoma cruzi subpopulations suggest non-vectorial parasite dispersal across the Motagua valley.

    Science.gov (United States)

    Pennington, Pamela M; Messenger, Louisa Alexandra; Reina, Jeffrey; Juárez, José G; Lawrence, Gena G; Dotson, Ellen M; Llewellyn, Martin S; Cordón-Rosales, Celia

    2015-11-01

    can be explained by multiple parasite-host switches between vector populations and selection or bottleneck processes across the Motagua Valley, with a possible role for didelphids in domestic transmission. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Pellicle transmission uniformity requirements

    Science.gov (United States)

    Brown, Thomas L.; Ito, Kunihiro

    1998-12-01

    Controlling critical dimensions of devices is a constant battle for the photolithography engineer. Current DUV lithographic process exposure latitude is typically 12 to 15% of the total dose. A third of this exposure latitude budget may be used up by a variable related to masking that has not previously received much attention. The emphasis on pellicle transmission has been focused on increasing the average transmission. Much less, attention has been paid to transmission uniformity. This paper explores the total demand on the photospeed latitude budget, the causes of pellicle transmission nonuniformity and examines reasonable expectations for pellicle performance. Modeling is used to examine how the two primary errors in pellicle manufacturing contribute to nonuniformity in transmission. World-class pellicle transmission uniformity standards are discussed and a comparison made between specifications of other components in the photolithographic process. Specifications for other materials or parameters are used as benchmarks to develop a proposed industry standard for pellicle transmission uniformity.

  7. The economics of thorium fuel cycles

    International Nuclear Information System (INIS)

    James, R.A.

    1978-01-01

    The individual cost components and the total fuel cycle costs for natural uranium and thorium fuel cycles are discussed. The thorium cycles are initiated by using either enriched uranium or plutonium. Subsequent thorium cycles utilize recycled uranium-233 and, where necessary, either uranium-235 or plutonium as topping. A calculation is performed to establish the economic conditions under which thorium cycles are economically attractive. (auth)

  8. Viability analysis of electric energy cogeneration in combined cycle with sugar-cane biomass gasification and natural gas; Analise de viabilidade da cogeracao de energia eletrica em ciclo combinado com gaseificacao de biomassa de cana-de-acucar e gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Correa Neto, Vicente

    2001-03-15

    The objective of this thesis is evaluate the technical and economic viability of electric energy generation projects using as fuel the biomass produced in the sugar cane Brazilian industry, specifically the cane trash, the straw and the leaves of the plant, as complemental option to the expansion of the Brazilian electric system, hour in phase of deep modification in the institutional scenery, through the sale of electric energy for direct consumers or utilities, characterizing the business possibilities for the ethanol distilleries already integrated into the energy reality of the country. The analyzed technology is thermoelectric generation with combined cycle, operating in cogeneration, integrated to biomass gasification systems for the production of combustible gas, with and without addition of natural gas. The considered technology is known by the acronym BIG/GTCC, originated in Biomass Integrate Gasification Combined Cycle Gas Turbine. The economic analysis is made herself through a modeling and construction of economy project curves based on the prices of the electric energy, of the natural gas and in the costs of the retired biomass in an mechanized way.(author)

  9. Coiled transmission line pulse generators

    Science.gov (United States)

    McDonald, Kenneth Fox

    2010-11-09

    Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

  10. Electric power transmission pricing regulations and efficiency

    International Nuclear Information System (INIS)

    Goldoni, G.

    1999-01-01

    An efficient-price mechanism for electricity transmission is very hard to find, essentially because of the natural monopoly condition of the grid and its peculiar interactions with generation. The use of Optimal Power Flow Models is difficult to implement and could be easily distorted by strategical behaviour of generators. These models, however, could became a valuable efficiency-test for actual transmission charges and codes [it

  11. Transmission Line Resonator Segmented with Series Capacitors

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Boer, Vincent; Petersen, Esben Thade

    2016-01-01

    Transmission line resonators are often used as coils in high field MRI. Due to distributed nature of such resonators, coils based on them produce inhomogeneous field. This work investigates application of series capacitors to improve field homogeneity along the resonator. The equations for optimal...... values of evenly distributed capacitors are presented. The performances of the segmented resonator and a regular transmission line resonator are compared....

  12. Transmission acoustic microscopy investigation

    Science.gov (United States)

    Maev, Roman; Kolosov, Oleg; Levin, Vadim; Lobkis, Oleg

    The nature of acoustic contrast, i.e. the connection of the amplitude and phase of the output signal of the acoustic microscope with the local values of the acoustic parameters of the sample (density, elasticity, viscosity) is a central problem of acoustic microscopy. A considerable number of studies have been devoted to the formation of the output signal of the reflection scanning acoustic microscope. For the transmission acoustic microscope (TAM) this problem has remained almost unstudied. Experimental investigation of the confocal system of the TAM was carried out on an independently manufactured laboratory mockup of the TAM with the working frequency of the 420 MHz. Acoustic lenses with the radius of curvature of about 500 microns and aperture angle of 45 deg were polished out in the end faces of two cylindrical sound conductors made from Al2O3 single crystals with an axis parallel to the axis C of the crystal (the length of the sound conductor is 20 mm; diameter, 6 mm). At the end faces of the sound conductor, opposite to the lenses, CdS transducers with a diameter of 2 mm were disposed. The electric channel of the TAM provided a possibility for registering the amplitude of the microscope output signal in the case of the dynamic range of the 50 dB.

  13. European natural gas

    International Nuclear Information System (INIS)

    Thackeray, Fred

    1999-11-01

    Contains Executive Summary and Chapters on: Main issues; Natural gas consumption and supply: statistics and key features of individual countries; Sectoral natural gas consumption; Indigenous production; Imports; Prices and taxes; The spot market: The interconnector; Forecasts of production and consumption and contracted imports; Progress of markets liberalisation; Effects of environmentalist developments; Transmission networks and storage; Some principal players. (Author)

  14. Transmission Integration | Grid Modernization | NREL

    Science.gov (United States)

    Transmission Integration Transmission Integration The goal of NREL's transmission integration integration issues and provide data, analysis, and models to enable the electric power system to more and finding solutions to address them to enable transmission grid integration. Capabilities Power

  15. CO2 cycle

    Science.gov (United States)

    Titus, Timothy N.; Byrne, Shane; Colaprete, Anthony; Forget, Francois; Michaels, Timothy I.; Prettyman, Thomas H.

    2017-01-01

    This chapter discusses the use of models, observations, and laboratory experiments to understand the cycling of CO2 between the atmosphere and seasonal Martian polar caps. This cycle is primarily controlled by the polar heat budget, and thus the emphasis here is on its components, including solar and infrared radiation, the effect of clouds (water- and CO2-ice), atmospheric transport, and subsurface heat conduction. There is a discussion about cap properties including growth and regression rates, albedos and emissivities, grain sizes and dust and/or water-ice contamination, and curious features like cold gas jets and araneiform (spider-shaped) terrain. The nature of the residual south polar cap is discussed as well as its long-term stability and ability to buffer atmospheric pressures. There is also a discussion of the consequences of the CO2 cycle as revealed by the non-condensable gas enrichment observed by Odyssey and modeled by various groups.

  16. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    -, č. 274 (2005), s. 1-26 ISSN 1211-3298 Institutional research plan: CEZ:AV0Z70850503 Keywords : coordination * crises * cycles and fluctuations Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp274.pdf

  17. Happy Cycling

    DEFF Research Database (Denmark)

    Geert Jensen, Birgitte; Nielsen, Tom

    2013-01-01

    og Interaktions Design, Aarhus Universitet under opgave teamet: ”Happy Cycling City – Aarhus”. Udfordringen i studieopgaven var at vise nye attraktive løsningsmuligheder i forhold til cyklens og cyklismens integration i byrum samt at påpege relationen mellem design og overordnede diskussioner af...

  18. Coordination cycles

    Czech Academy of Sciences Publication Activity Database

    Steiner, Jakub

    2008-01-01

    Roč. 63, č. 1 (2008), s. 308-327 ISSN 0899-8256 Institutional research plan: CEZ:AV0Z70850503 Keywords : global games * coordination * crises * cycles and fluctuations Subject RIV: AH - Economics Impact factor: 1.333, year: 2008

  19. Series Transmission Line Transformer

    Science.gov (United States)

    Buckles, Robert A.; Booth, Rex; Yen, Boris T.

    2004-06-29

    A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

  20. Unpredictability and the transmission of numbers

    Science.gov (United States)

    Myers, John M.; Madjid, F. Hadi

    2016-03-01

    Curiously overlooked in physics is its dependence on the transmission of numbers. For example, the transmission of numerical clock readings is implicit in the concept of a coordinate system. The transmission of numbers and other logical distinctions is often achieved over a computer-mediated communications network in the face of an unpredictable environment. By unpredictable we mean something stronger than the spread of probabilities over given possible outcomes, namely an opening to unforeseeable possibilities. Unpredictability, until now overlooked in theoretical physics, makes the transmission of numbers interesting. Based on recent proofs within quantum theory that provide a theoretical foundation to unpredictability, here we show how regularities in physics rest on a background of channels over which numbers are transmitted. As is known to engineers of digital communications, numerical transmissions depend on coordination reminiscent of the cycle of throwing and catching by players tossing a ball back and forth. In digital communications, the players are computers, and the required coordination involves unpredictably adjusting "live clocks" that step these computers through phases of a cycle. We show how this phasing, which we call logical synchronization, constrains number-carrying networks, and, if a spacetime manifold in invoked, put "stripes" on spacetime. Via its logically synchronized channels, a network of live clocks serves as a reference against which to locate events. Such a network in any case underpins a coordinate frame, and in some cases the direct use of a network can be tailored to investigate an unpredictable environment. Examples include explorations of gravitational variations near Earth.

  1. The plutonium fuel cycles

    International Nuclear Information System (INIS)

    Pigford, T.H.; Ang, K.P.

    1975-01-01

    The quantities of plutonium and other fuel actinides have been calculated for equilibrium fuel cycles for 1000-MW water reactors fueled with slightly enriched uranium, water reactors fueled with plutonium and natural uranium, fast-breder reactors, gas-cooled reactors fueled with thorium and highly enriched uranium, and gas-cooled reactors fueled with thorium, plutonium and recycled uranium. The radioactivity quantities of plutonium, americium and curium processed yearly in these fuel cycles are greatest for the water reactors fueled with natural uranium and recycled plutonium. The total amount of actinides processed is calculated for the predicted future growth of the U.S. nuclear power industry. For the same total installed nuclear power capacity, the introduction of the plutonium breeder has little effect upon the total amount of plutonium in this century. The estimated amount of plutonium in the low-level process wastes in the plutonium fuel cycles is comparable to the amount of plutonium in the high-level fission product wastes. The amount of plutonium processed in the nuclear fuel cycles can be considerably reduced by using gas-cooled reactors to consume plutonium produced in uranium-fueled water reactors. These, and other reactors dedicated for plutonium utilization, could be co-located with facilities for fuel reprocessing ad fuel fabrication to eliminate the off-site transport of separated plutonium. (author)

  2. Drivers of Tuberculosis Transmission.

    Science.gov (United States)

    Mathema, Barun; Andrews, Jason R; Cohen, Ted; Borgdorff, Martien W; Behr, Marcel; Glynn, Judith R; Rustomjee, Roxana; Silk, Benjamin J; Wood, Robin

    2017-11-03

    Measuring tuberculosis transmission is exceedingly difficult, given the remarkable variability in the timing of clinical disease after Mycobacterium tuberculosis infection; incident disease can result from either a recent (ie, weeks to months) or a remote (ie, several years to decades) infection event. Although we cannot identify with certainty the timing and location of tuberculosis transmission for individuals, approaches for estimating the individual probability of recent transmission and for estimating the fraction of tuberculosis cases due to recent transmission in populations have been developed. Data used to estimate the probable burden of recent transmission include tuberculosis case notifications in young children and trends in tuberculin skin test and interferon γ-release assays. More recently, M. tuberculosis whole-genome sequencing has been used to estimate population levels of recent transmission, identify the distribution of specific strains within communities, and decipher chains of transmission among culture-positive tuberculosis cases. The factors that drive the transmission of tuberculosis in communities depend on the burden of prevalent tuberculosis; the ways in which individuals live, work, and interact (eg, congregate settings); and the capacity of healthcare and public health systems to identify and effectively treat individuals with infectious forms of tuberculosis. Here we provide an overview of these factors, describe tools for measurement of ongoing transmission, and highlight knowledge gaps that must be addressed. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  3. Historicising the Hydrosocial Cycle

    Directory of Open Access Journals (Sweden)

    Jeremy J. Schmidt

    2014-02-01

    Full Text Available This paper examines the historical claims made in support of the hydrosocial cycle. In particular, it considers how arguments advancing the hydrosocial cycle make historical claims regarding modernist conceptions of what water is (i.e. H2O and its fit with society. The paper gives special emphasis to the society/nature dualism and to the notion of agency as key sites of contest in arguments regarding the hydrosocial cycle. It finds that, while several versions of the hydrosocial cycle seek to advance a political ecology more sensitive to non-human actions, these same accounts often do not address the robust account of non-human agency in the historical record. Evidence is presented regarding water’s agency amongst late 19th and early 20th century architects of key water management norms in the United States. This evidence troubles accounts of the hydrosocial cycle that critique the US experience and suggests new directions for rethinking the role of historical and institutional norms in water policy.

  4. Multiparameter Cell Cycle Analysis.

    Science.gov (United States)

    Jacobberger, James W; Sramkoski, R Michael; Stefan, Tammy; Woost, Philip G

    2018-01-01

    Cell cycle cytometry and analysis are essential tools for studying cells of model organisms and natural populations (e.g., bone marrow). Methods have not changed much for many years. The simplest and most common protocol is DNA content analysis, which is extensively published and reviewed. The next most common protocol, 5-bromo-2-deoxyuridine S phase labeling detected by specific antibodies, is also well published and reviewed. More recently, S phase labeling using 5'-ethynyl-2'-deoxyuridine incorporation and a chemical reaction to label substituted DNA has been established as a basic, reliable protocol. Multiple antibody labeling to detect epitopes on cell cycle regulated proteins, which is what this chapter is about, is the most complex of these cytometric cell cycle assays, requiring knowledge of the chemistry of fixation, the biochemistry of antibody-antigen reactions, and spectral compensation. However, because this knowledge is relatively well presented methodologically in many papers and reviews, this chapter will present a minimal Methods section for one mammalian cell type and an extended Notes section, focusing on aspects that are problematic or not well described in the literature. Most of the presented work involves how to segment the data to produce a complete, progressive, and compartmentalized cell cycle analysis from early G1 to late mitosis (telophase). A more recent development, using fluorescent proteins fused with proteins or peptides that are degraded by ubiquitination during specific periods of the cell cycle, termed "Fucci" (fluorescent, ubiquitination-based cell cycle indicators) provide an analysis similar in concept to multiple antibody labeling, except in this case cells can be analyzed while living and transgenic organisms can be created to perform cell cycle analysis ex or in vivo (Sakaue-Sawano et al., Cell 132:487-498, 2007). This technology will not be discussed.

  5. software for natural gas pipeline design and simulation

    African Journals Online (AJOL)

    Global Journal

    2017-01-17

    Jan 17, 2017 ... investment and operating cost required for natural gas pipeline transmission ... In the early development of the natural gas transmission industry, pressures were low and ..... The software has an error control capability in.

  6. Cultural Transmission of Civicness

    DEFF Research Database (Denmark)

    Ljunge, Jan Martin

    2012-01-01

    This paper estimates the intergeneration transmission of civicness by studying second generation immigrants in 29 European countries with ancestry in 83 nations. There is significant transmission of civicness both on the mother’s and the father’s side. The estimates are quantitatively significant...

  7. Cultural Transmission of Civicness

    DEFF Research Database (Denmark)

    Ljunge, Jan Martin

    This paper estimates the intergeneration transmission of civicness by studying second generation immigrants in 29 European countries with ancestry in 83 nations. There is significant transmission of civicness both on the mother’s and the father’s side. The estimates are quantitatively significant...

  8. Poverty and price transmission

    DEFF Research Database (Denmark)

    Elleby, Christian

    A key parameter determining the welfare impact from a world market shock is the transmission elasticity which measures the average domestic response to an international price change. Many studies have estimated price transmission elasticities for a large number of countries but the variation in t...

  9. Transmission market support system

    International Nuclear Information System (INIS)

    Reinschmidt, K.F.; Coles, B.C.

    1995-01-01

    An interactive, computer-based market support system has been developed for transmission access that is efficient, equitable, and fair to all parties concerned with electrical transmission: utilities, electric generators, owners of transmission networks, and wholesale purchasers of electrical power. Each participant transmits electronically to the computer system his proposed price schedule for buying, selling, or transmitting power for each future time period. The price for transmission on a single line in one direction can differ from the price in the other direction. The total quantity offered in the transmission bid represents the capacity of the line, and the flow on the line cannot exceed this value. The system automatically computes the prices that clear the market; that is, the price that each generator receives at each bus, the price that each transmission operator receives on each line, and the price that each customer pays at each bus. The computer system maximizes the benefits to all three classes while satisfying the electrical characteristics of the transmission system by means of load flow calculations. Customers never pay more than their bid prices (but may pay less), and generators and transmission operators never receive less than their bid prices (but may receive more). The price at each bus applies to all buyers and sellers at that bus: all buyers at the same bus pay the same price and all generators at a bus receive the same price

  10. Pricing transmission services

    International Nuclear Information System (INIS)

    Haaden, E.

    1995-01-01

    The price structure for transmission of electric power through the main lines in Sweden is analyzed. After deregulation of the electricity market, the main transmission lines are owned by a separate national company, with no interests from the power producers. Comparisons are made to ideal marginal price structures. 6 refs

  11. Eliminating Perinatal HIV Transmission

    Centers for Disease Control (CDC) Podcasts

    In this podcast, CDC’s Dr. Steve Nesheim discusses perinatal HIV transmission, including the importance of preventing HIV among women, preconception care, and timely HIV testing of the mother. Dr. Nesheim also introduces the revised curriculum Eliminating Perinatal HIV Transmission intended for faculty of OB/GYN and pediatric residents and nurse midwifery students.

  12. Fuel cycle

    International Nuclear Information System (INIS)

    Bahm, W.

    1989-01-01

    The situation of the nuclear fuel cycle for LWR type reactors in France and in the Federal Republic of Germany was presented in 14 lectures with the aim to compare the state-of-the-art in both countries. In addition to the momentarily changing fuilds of fuel element development and fueling strategies, the situation of reprocessing, made interesting by some recent developmnts, was portrayed and differences in ultimate waste disposal elucidated. (orig.) [de

  13. Cell Cycle Control by PTEN.

    Science.gov (United States)

    Brandmaier, Andrew; Hou, Sheng-Qi; Shen, Wen H

    2017-07-21

    Continuous and error-free chromosome inheritance through the cell cycle is essential for genomic stability and tumor suppression. However, accumulation of aberrant genetic materials often causes the cell cycle to go awry, leading to malignant transformation. In response to genotoxic stress, cells employ diverse adaptive mechanisms to halt or exit the cell cycle temporarily or permanently. The intrinsic machinery of cycling, resting, and exiting shapes the cellular response to extrinsic stimuli, whereas prevalent disruption of the cell cycle machinery in tumor cells often confers resistance to anticancer therapy. Phosphatase and tensin homolog (PTEN) is a tumor suppressor and a guardian of the genome that is frequently mutated or deleted in human cancer. Moreover, it is increasingly evident that PTEN deficiency disrupts the fundamental processes of genetic transmission. Cells lacking PTEN exhibit cell cycle deregulation and cell fate reprogramming. Here, we review the role of PTEN in regulating the key processes in and out of cell cycle to optimize genomic integrity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Electric transmission technology

    International Nuclear Information System (INIS)

    Shah, K.R.

    1990-01-01

    Electric transmission technology has matured and can transmit bulk power more reliably and economically than the technology 10 years ago.In 1882, Marcel Depres transmitted 15 kW electric power at 2 kV, using a constant direct current; present transmission voltages have risen to ± 600 kV direct current (DC) and 765 kV alternating current (AC), and it is now possible to transmit bulk electric power at voltages as high as ± 1000 kV DC and 1500 kV AC. Affordable computer systems are now available to optimize transmission reliably. New materials have reduced the bulk of insulation for lines and equipment. New conducting materials and configurations have reduced losses in transmission. Advances in line structures and conductor motion, understanding of flashover characteristics of insulators and air-gaps and electrical performance of lines have resulted in more compact urban transmission lines. (author). 15 refs., 7 tabs., 11 figs

  15. Microwave energy transmission

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hiroshi [Kyoto Univ. (Japan)

    1989-03-05

    Laying stress on the technological problems and effect on the environment of microwave energy transmission, recent scientific and engineering problems and related subjects are described. Because no fuel is required for the solar power generation, the power generation system can not be considered as an expensive one when the unit cost of energy is taken into consideration. Some of the important technological problems in the microwave energy transmission are accurate microwave beam control technology to receiving stations and improvement in the efficiency of transmission system. Microwave energy beam has effects on living bodies, communication, and plasma atmosphere of the earth. Microwave energy transmission using a space flyer unit is scheduled. Its objective is the development of microwave wireless transmission technology and the study of the correlation between high power microwave and ionosphere plasma. Experiments on such a small scale application as a microwave driven space ship to bring results seem also important. 12 refs., 13 figs.

  16. Contribuição ao estudo da história natural de enteroparasitas em uma comunidade fechada: II. Mecanismos de transmissão de enteroparasitas em uma comunidade fechada

    Directory of Open Access Journals (Sweden)

    Pedro P. Chieffi

    1974-04-01

    Full Text Available Para estabelecer os mecanismos de transmissão de enteroparasitas entre a população de um orfanato, os autores pesquisaram a presença de ovos de helmintos e cistos de protozoários nas mãos, unhas e roupas das internas; nos objetos e peças de banheiros coletivos e poeira de dormitórios. Realizaram também exame bacteriológico da água que abastece a instituição. Os resultados são apresentados e discutidos.

  17. Determinants of Arbovirus Vertical Transmission in Mosquitoes.

    Directory of Open Access Journals (Sweden)

    Sebastian Lequime

    2016-05-01

    Full Text Available Vertical transmission (VT and horizontal transmission (HT of pathogens refer to parental and non-parental chains of host-to-host transmission. Combining HT with VT enlarges considerably the range of ecological conditions in which a pathogen can persist, but the factors governing the relative frequency of each transmission mode are poorly understood for pathogens with mixed-mode transmission. Elucidating these factors is particularly important for understanding the epidemiology of arthropod-borne viruses (arboviruses of public health significance. Arboviruses are primarily maintained by HT between arthropod vectors and vertebrate hosts in nature, but are occasionally transmitted vertically in the vector population from an infected female to her offspring, which is a proposed maintenance mechanism during adverse conditions for HT. Here, we review over a century of published primary literature on natural and experimental VT, which we previously assembled into large databases, to identify biological factors associated with the efficiency of arbovirus VT in mosquito vectors. Using a robust statistical framework, we highlight a suite of environmental, taxonomic, and physiological predictors of arbovirus VT. These novel insights contribute to refine our understanding of strategies employed by arboviruses to persist in the environment and cause substantial public health concern. They also provide hypotheses on the biological processes underlying the relative VT frequency for pathogens with mixed-mode transmission that can be tested empirically.

  18. Regulatory assessment with regulatory flexibility analysis : draft regulatory evaluation - Notice of Proposed Rulemaking -- Pipeline Safety : safety standards for increasing the maximum allowable operating pressure for natural gas transmission pipelines.

    Science.gov (United States)

    2008-02-01

    The Pipeline and Hazardous Materials Safety Administration (PHMSA) is proposing changes to the Federal pipeline safety regulations in 49 CFR Part 192, which cover the transportation of natural gas by pipeline. Specifically, PHMSA proposes allowing na...

  19. Hypoxia-inducible factor-1α plays roles in Epstein-Barr virus's natural life cycle and tumorigenesis by inducing lytic infection through direct binding to the immediate-early BZLF1 gene promoter.

    Directory of Open Access Journals (Sweden)

    Richard J Kraus

    2017-06-01

    Full Text Available When confronted with poor oxygenation, cells adapt by activating survival signaling pathways, including the oxygen-sensitive transcriptional regulators called hypoxia-inducible factor alphas (HIF-αs. We report here that HIF-1α also regulates the life cycle of Epstein-Barr virus (EBV. Incubation of EBV-positive gastric carcinoma AGS-Akata and SNU-719 and Burkitt lymphoma Sal and KemIII cell lines with a prolyl hydroxylase inhibitor, L-mimosine or deferoxamine, or the NEDDylation inhibitor MLN4924 promoted rapid and sustained accumulation of both HIF-1α and lytic EBV antigens. ShRNA knockdown of HIF-1α significantly reduced deferoxamine-mediated lytic reactivation. HIF-1α directly bound the promoter of the EBV primary latent-lytic switch BZLF1 gene, Zp, activating transcription via a consensus hypoxia-response element (HRE located at nt -83 through -76 relative to the transcription initiation site. HIF-1α did not activate transcription from the other EBV immediate-early gene, BRLF1. Importantly, expression of HIF-1α induced EBV lytic-gene expression in cells harboring wild-type EBV, but not in cells infected with variants containing base-pair substitution mutations within this HRE. Human oral keratinocyte (NOK and gingival epithelial (hGET cells induced to differentiate by incubation with either methyl cellulose or growth in organotypic culture accumulated both HIF-1α and Blimp-1α, another cellular factor implicated in lytic reactivation. HIF-1α activity also accumulated along with Blimp-1α during B-cell differentiation into plasma cells. Furthermore, most BZLF1-expressing cells observed in lymphomas induced by EBV in NSG mice with a humanized immune system were located distal to blood vessels in hypoxic regions of the tumors. Thus, we conclude that HIF-1α plays central roles in both EBV's natural life cycle and EBV-associated tumorigenesis. We propose that drugs that induce HIF-1α protein accumulation are good candidates for

  20. Biosignatures of Exposure/Transmission and Immunity.

    Science.gov (United States)

    King, Christopher L; Davies, D Huw; Felgner, Phil; Baum, Elizabeth; Jain, Aarti; Randall, Arlo; Tetteh, Kevin; Drakeley, Christopher J; Greenhouse, Bryan

    2015-09-01

    A blood test that captures cumulative exposure over time and assesses levels of naturally acquired immunity (NAI) would provide a critical tool to monitor the impact of interventions to reduce malaria transmission and broaden our understanding of how NAI develops around the world as a function of age and exposure. This article describes a collaborative effort in multiple International Centers of Excellence in Malaria Research (ICEMRs) to develop such tests using malaria-specific antibody responses as biosignatures of transmission and immunity. The focus is on the use of Plasmodium falciparum and Plasmodium vivax protein microarrays to identify a panel of the most informative antibody responses in diverse malaria-endemic settings representing an unparalleled spectrum of malaria transmission and malaria species mixes before and after interventions to reduce malaria transmission. © The American Society of Tropical Medicine and Hygiene.

  1. Short report: secondary transmission in porcine cysticercosis: description and their potential implications for control sustainability.

    Science.gov (United States)

    Gonzalez, Armando E; López-Urbina, Teresa; Tsang, Byron Y; Gavidia, César M; Garcia, Héctor H; Silva, María E; Ramos, Daphne D; Manzanedo, Rafael; Sánchez-Hidalgo, Lelia; Gilman, Robert H; Tsang, Victor C W

    2005-09-01

    Taenia solium taeniasis/cysticercosis is one of few potentially eradicable infectious diseases and is the target of control programs in several countries. The larval stage of this zoonotic cestode invades the human brain and is responsible for most cases of adult-onset epilepsy in the world. The pig is the natural intermediate host, harboring the larvae or cysticerci. Our current understanding of the life cycle implicates humans as the only definitive host and tapeworm carrier (developing taeniasis) and thus the sole source of infective eggs that are responsible for cysticercosis in both human and pigs through oral-fecal transmission. Here we show evidence of an alternative pig-to-pig route of transmission, previously not suspected to exist. In a series of four experiments, naive sentinel pigs were exposed to pigs that had been infected orally with tapeworm segments (containing infective eggs) and moved to a clean environment. Consistently in all four experiments, at least one of the sentinel pigs became seropositive or infected with parasite cysts with much lower cyst burdens than did primarily infected animals. Second-hand transmission of Taenia solium eggs could explain the overdispersed pattern of porcine cysticercosis, with few pigs harboring heavy parasite burdens and many more harboring small numbers of parasites. This route of transmission opens new avenues for consideration with respect to control strategies.

  2. Understanding Ebola Virus Transmission

    Directory of Open Access Journals (Sweden)

    Seth Judson

    2015-02-01

    Full Text Available An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus.

  3. [The control of vectorial transmission].

    Science.gov (United States)

    Silveira, Antônio Carlos; Dias, João Carlos Pinto

    2011-01-01

    Between 1950 and 1951, the first Prophylactic campaign against Chagas Diseases was carried on in Brazil by the so existing Serviço Nacional de Malária. The actions involving chemical vector control comprehended 74 municipalities along the Rio Grande Valley, between the States of São Paulo and Minas Gerais. Ever since, until 1975, the activities were performed according the availability of resources, being executed with more or less regularity and coverage. At that time, Chagas disease did no represent priority, in comparison with other endemic diseases prevalent in the Country. Even so, taking into account the accumulated data along those 25 years, the volume of work realized cannot be considered despicable. Nevertheless, it was few consistent, in terms of its impact on disease transmission. In 1975, with an additional injection of resources surpassed from the malaria program, plus the methodological systematization of the activities, and with the results of two extensive national inquiries (entomologic and serologic), the activities for vector control could be performed regularly, following two basic principles: interventions in always contiguous areas, progressively enlarged, and sustainability (continuity) of the activities, until being attained determined requirements and purpose previously established. Such actions and strategies lead into the exhaustion of the populations of the principal vector species, Triatoma infestans, no autochthonous and exclusively domiciliary, as well as the control of the domiciliary colonization of autochthonous species important to disease transmission. Vector transmission today is being considered residual, by means of some few native and peridomestic species, such as Triatoma brasiliensis and Triatoma pseudomaculata. There is, also, the risk of progressive domiciliation of some species before considered sylvatic, such as Panstrongylus lutzi and Triatoma rubrovaria. Finally, there is the possibility of the occurrence of cases

  4. Introducing advanced nuclear fuel cycles in Canada

    International Nuclear Information System (INIS)

    Duret, M.F.

    1978-05-01

    The ability of several different advanced fuel cycles to provide energy for a range of energy growth scenarios has been examined for a few special situations of interest in Canada. Plutonium generated from the CANDU-PHW operating on natural uranium is used to initiate advanced fuel cycles in the year 2000. The four fuel cycles compared are: 1) natural uranium in the CANDU-PHW; 2) high burnup thorium cycle in the CANDU-PHW; 3) self-sufficient thorium cycle in the CANDU-PHW; 4) plutonium-uranium cycle in a fast breeder reactor. The general features of the results are quite clear. While any plutonium generated prior to the introduction of the advanced fuel cycle remains, system requirements for natural uranium for each of the advanced fuel cycles are the same and are governed by the rate at which plants operating on natural uranium can be retired. When the accumulated plutonium inventory has been entirely used, natural uranium is again required to provide inventory for the advanced fuel cycle reactors. The time interval during which no uranium is required varies only from about 25 to 40 years for both thorium cycles, depending primarily on the energy growth rate. The breeder does not require the entire plutonium inventory produced and so would call for less processing of fuel from the PHW reactors. (author)

  5. Eco-design of power transmissions systems

    International Nuclear Information System (INIS)

    Wang, W.

    2011-01-01

    The demand to preserve the environment and form a sustainable development is greatly increasing in the recent decades all over the world, and this environmental concern is also merged in electrical power industry, resulting in many eco-design approaches in Transmission and Distribution (T and D) industries. As a method of eco-design, Life Cycle Assessment (LCA) is a systematic tool that enables the assessment of the environmental impacts of a product or service throughout its entire life cycle, i.e. raw material production, manufacture, distribution, use and disposal including all intervening transportation steps necessary or caused by the product's existence. In T and D industries, LCA has been done for a lot of products individually, in order to see one product's environmental impacts and to seek for ways of improving its environmental performance. This eco-design for product approach is a rather well-developed trend, however, as only a single electrical product cannot provide the electrical power to users, electrical system consists of a huge number of components, in order to investigate system's environmental profile, the entire environmental profiles of different composing products has to be integrated systematically, that is to say, a system approach is needed. Under this philosophy, the study 'Eco-design of Power Transmission Systems' is conducted in this thesis, with the purpose of analysing the transmission systems' environmental impacts, locating the major environmental burden sources of transmission systems, selecting and/or developing methodologies of reducing its environmental impacts. (author)

  6. Transmissions in vehicles 2010

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Within the international VDI congress 'Gears in vehicles 2010' of the VDI Wissensforum GmbH (Duesseldorf, Federal Republic of Germany) between 22nd and 23rd June, 2010, in Friedrichshafen (Federal Republic of Germany), the following lectures were held: (1) 8HP70H - The moldhybrid transmission from ZF - Cjallenges and achievements (P. Gutmann); (2) GETRAG boosted range extender - A highly flexible electric powertrain for maximum CO{sub 2} reduction (S. Huepkes); (3) E-Transmission between full-hybrid and E-drive (P. Tenberge); (4) Reducing NO{sub x} and particulate emissions in electrified drivelines (R. Kuberczyk); (5) Simulation aided HEV and EV development: from the component to the whole powertrain (A. Gacometti); (6) Investigations on operating behaviour of the optimized CVT hybrid driveline (B.-R. Hoehn); (7) Customer-oriented dimensioning of electrified drivetrains (M. Eghtessad); (8) Decentralized optimal control strategy for parallel hybrid electric vehicles (A. Frenkel); (9) The new generation 6-speed automatic transmission AF40 (G. Bednarek); (10) Customized mechatronic solutions for integrated transmission control units (M. Wieczorek); (11) The optimal automatic transmission for front-transverse applications - Planetary transmissions or dual clutch transmissions? (G. Gumpoltsberger); (12) The new shift-by-wire gearshift lever for the Audi A8 - Requirements and concept (T. Guttenbergere); (13) The new shift-by-wire gearshift lever for the Audi A8 - Realization (A. Giefer); (14) Fuel-efficient transmissions of the future: Calculation of the efficiency factor for vehicle transmissions (B. Volpert); (15) HT-ACM: A new polymer generation for static and dynamic gearbox sealing solutions (E. Osen); (16) 'Energy efficiency equipped solutions by SKF' for power train applications - A contribution to CO{sub 2} - emission reduction and sustainability (T. Bobke); (17) 6-Ratio planetary shift transmission controlled by 4 external brakes, and design

  7. Safe cycling!

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    The HSE Unit will be running a cycling safety campaign at the entrances to CERN's restaurants on 14, 15 and 16 May. Pop along to see if they can persuade you to get back in the saddle!   With summer on its way, you might feel like getting your bike out of winter storage. Well, the HSE Unit has come up with some original ideas to remind you of some of the most basic safety rules. This year, the prevention campaign will be focussing on three themes: "Cyclists and their equipment", "The bicycle on the road", and "Other road users". This is an opportunity to think about the condition of your bike as well as how you ride it. From 14 to 16 May, representatives of the Swiss Office of Accident Prevention and the Touring Club Suisse will join members of the HSE Unit at the entrances to CERN's restaurants to give you advice on safe cycling (see box). They will also be organising three activity stands where you can test your knowle...

  8. Cycle 22

    International Nuclear Information System (INIS)

    Kappernman, J.G.; Albertson, V.D.

    1991-01-01

    This paper reports that for many electric utility systems, Solar Cycle 22 has been the first introduction to the phenomena of Geomagnetic Disturbances and the disrupting and damaging effects that they can have upon modern power systems. For all intents and purposes, Power Industry awareness of Cycle 22 started with a bang during the Great Geomagnetic Storm of March 13, 1989. This storm caused a blackout to the entire Province of Quebec, permanently damaged a large nuclear plant GSU transformer in New Jersey, and created enough havoc across the entire North American power grid to create the plausible threat of a massive power system blackout. The flurry of activity and investigation that followed has led many engineers to realize that their power systems are indeed vulnerable to this phenomena and if anything are becoming ever more vulnerable as the system grows to meet future requirements. As a result some organizations such as Hydro Quebec, PSE and G, and the PJM Pool now implement strategic measures as a remedial response to detection of geomagnetic storm conditions. Many more companies pay particularly close attention to storm forecasts and alerts, and the industry in general has accelerated research and monitoring activities through their own means of in concert with the Electric Power Research Institute (EPRI)

  9. Kansas Electric Transmission Lines

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set is a digital representation of the EletcircTransmission lines for the State of Kansas as maintained by the Kansas Corporation Commission. Data is...

  10. ECRH transmission system

    International Nuclear Information System (INIS)

    Tancredi, J.

    1983-01-01

    Hughes, Electron Dynamics Division is developing gyrotrons for ECRH requirements. In the development program, techniques have been evolved for transmission system components. These techniques include over-moded waveguide tapers, high average power windows, and rf water loads for testing

  11. Electric Power Transmission Lines

    Data.gov (United States)

    Department of Homeland Security — Transmission Lines are the system of structures, wires, insulators and associated hardware that carry electric energy from one point to another in an electric power...

  12. Tick-Borne Transmission of Murine Gammaherpesvirus 68

    Directory of Open Access Journals (Sweden)

    Valeria Hajnická

    2017-10-01

    Full Text Available Herpesviruses are a large group of DNA viruses infecting mainly vertebrates. Murine gammaherpesvirus 68 (MHV68 is often used as a model in studies of the pathogenesis of clinically important human gammaherpesviruses such as Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus. This rodent virus appears to be geographically widespread; however, its natural transmission cycle is unknown. Following detection of MHV68 in field-collected ticks, including isolation of the virus from tick salivary glands and ovaries, we investigated whether MHV68 is a tick-borne virus. Uninfected Ixodes ricinus ticks were shown to acquire the virus by feeding on experimentally infected laboratory mice. The virus survived tick molting, and the molted ticks transmitted the virus to uninfected laboratory mice on which they subsequently fed. MHV68 was isolated from the tick salivary glands, consistent with transmission via tick saliva. The virus survived in ticks without loss of infectivity for at least 120 days, and subsequently was transmitted vertically from one tick generation to the next, surviving more than 500 days. Furthermore, the F1 generation (derived from F0 infected females transmitted MHV68 to uninfected mice on which they fed, with MHV68 M3 gene transcripts detected in blood, lung, and spleen tissue of mice on which F1 nymphs and F1 adults engorged. These experimental data fulfill the transmission criteria that define an arthropod-borne virus (arbovirus, the largest biological group of viruses. Currently, African swine fever virus (ASFV is the only DNA virus recognized as an arbovirus. Like ASFV, MHV68 showed evidence of pathogenesis in ticks. Previous studies have reported MHV68 in free-living ticks and in mammals commonly infested with I. ricinus, and neutralizing antibodies to MHV68 have been detected in large mammals (e.g., deer including humans. Further studies are needed to determine if these reports are the result of tick-borne transmission

  13. Airspace: Antarctic Sound Transmission

    OpenAIRE

    Polli, Andrea

    2009-01-01

    This paper investigates how sound transmission can contribute to the public understanding of climate change within the context of the Poles. How have such transmission-based projects developed specifically in the Arctic and Antarctic, and how do these works create alternative pathways in order to help audiences better understand climate change? The author has created the media project Sonic Antarctica from a personal experience of the Antarctic. The work combines soundscape recordings and son...

  14. Offshore Transmission Technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-10-15

    The purpose of this document is to give an overview of offshore electricity transmission technologies. In particular this document is concerned with the use of High Voltage Direct Current (HVDC) systems and more specifically with the development of Voltage Source Converter (VSC) technology. This report outlines the current state of the main technology groups required for offshore HVDC transmission as well as giving examples of offshore projects (both current and future). Finally some indications of likely unit costs for HV assets are given.

  15. Eliminating Perinatal HIV Transmission

    Centers for Disease Control (CDC) Podcasts

    2012-11-26

    In this podcast, CDC’s Dr. Steve Nesheim discusses perinatal HIV transmission, including the importance of preventing HIV among women, preconception care, and timely HIV testing of the mother. Dr. Nesheim also introduces the revised curriculum Eliminating Perinatal HIV Transmission intended for faculty of OB/GYN and pediatric residents and nurse midwifery students.  Created: 11/26/2012 by Division of HIV/AIDS Prevention.   Date Released: 11/26/2012.

  16. Contribuição ao estudo da história natural de enteroparasitas em uma comunidade fechada: II. Mecanismos de transmissão de enteroparasitas em uma comunidade fechada

    Directory of Open Access Journals (Sweden)

    Pedro P. Chieffi

    1974-04-01

    Full Text Available Para estabelecer os mecanismos de transmissão de enteroparasitas entre a população de um orfanato, os autores pesquisaram a presença de ovos de helmintos e cistos de protozoários nas mãos, unhas e roupas das internas; nos objetos e peças de banheiros coletivos e poeira de dormitórios. Realizaram também exame bacteriológico da água que abastece a instituição. Os resultados são apresentados e discutidos.In the present paper the authons present some studies on the epidemiology of enteroparasites in an orphanage, in Londrina, Paraná, Brazil.

  17. 3D7-derived Plasmodium falciparum erythrocyte membrane protein 1 is a frequent target of naturally acquired antibodies recognizing protein domains in a particular pattern independent of malaria transmission intensity

    DEFF Research Database (Denmark)

    Joergensen, Louise; Vestergaard, Lasse S; Turner, Louise

    2007-01-01

    Protection against Plasmodium falciparum malaria is largely mediated by IgG against surface Ags such as the erythrocyte membrane protein 1 family (PfEMP1) responsible for antigenic variation and sequestration of infected erythrocytes. PfEMP1 molecules can be divided into groups A, B/A, B, C, and B......, the sequence by which individuals acquired Abs to particular constructs was largely the same in the three villages. This indicates that the pattern of PfEMP1 expression by parasites transmitted at the different sites was similar, suggesting that PfEMP1 expression is nonrandom and shaped by host......-parasite relationship factors operating at all transmission intensities....

  18. Optical analog transmission device

    International Nuclear Information System (INIS)

    Ikawa, Shinji.

    1994-01-01

    The present invention concerns a device such as electro-optical conversion elements, optoelectric-electric elements and optical transmission channel, not undergoing deleterious effects on the efficiency of conversion and transmission due to temperature, and aging change. That is, a sine wave superposing means superposes, on a detector signal to be transmitted, a sine-wave signal having a predetermined amplitude and at a frequency lower than that of the detector signal. An optoelectric conversion means converts the electric signal as the signal of the sine-wave signal superposing means into an optical signal and outputs the same to an optical transmitting channel. The optoelectric conversion means converts the transmitted signal to an electric signal. A discriminating means discriminates the electric signal into a detector signal and a sine-wave signal. A calculating means calculates an optical transmitting efficiency of the transmitting channel based on the amplitude of the discriminated sine-wave signal. A processing means compensates an amplitude value of the detector signals discriminated by the discriminating means based on the optical transmission efficiency. As a result, an optical analog transmission device can be attained, which conducts optical transmission at a high accuracy without undergoing the defective effects of the optical transmission efficiency. (I.S.)

  19. National transmission grid study

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, Spencer [USDOE Office of the Secretary of Energy, Washington, DC (United States)

    2003-05-31

    The National Energy Policy Plan directed the U.S. Department of Energy (DOE) to conduct a study to examine the benefits of establishing a national electricity transmission grid and to identify transmission bottlenecks and measures to address them. DOE began by conducting an independent analysis of U.S. electricity markets and identifying transmission system bottlenecks using DOE’s Policy Office Electricity Modeling System (POEMS). DOE’s analysis, presented in Section 2, confirms the central role of the nation’s transmission system in lowering costs to consumers through increased trade. More importantly, DOE’s analysis also confirms the results of previous studies, which show that transmission bottlenecks and related transmission system market practices are adding hundreds of millions of dollars to consumers’ electricity bills each year. A more detailed technical overview of the use of POEMS is provided in Appendix A. DOE led an extensive, open, public input process and heard a wide range of comments and recommendations that have all been considered.1 More than 150 participants registered for three public workshops held in Detroit, MI (September 24, 2001); Atlanta, GA (September 26, 2001); and Phoenix, AZ (September 28, 2001).

  20. Wireless data signal transmission system

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a method for providing a radio frequency signal for transmission, a system for providing a radio frequency signal for transmission and a method for wireless data transmission between a transmitter and a receiver.......The present invention relates to a method for providing a radio frequency signal for transmission, a system for providing a radio frequency signal for transmission and a method for wireless data transmission between a transmitter and a receiver....

  1. Vector independent transmission of the vector-borne bluetongue virus.

    Science.gov (United States)

    van der Sluijs, Mirjam Tineke Willemijn; de Smit, Abraham J; Moormann, Rob J M

    2016-01-01

    Bluetongue is an economically important disease of ruminants. The causative agent, Bluetongue virus (BTV), is mainly transmitted by insect vectors. This review focuses on vector-free BTV transmission, and its epizootic and economic consequences. Vector-free transmission can either be vertical, from dam to fetus, or horizontal via direct contract. For several BTV-serotypes, vertical (transplacental) transmission has been described, resulting in severe congenital malformations. Transplacental transmission had been mainly associated with live vaccine strains. Yet, the European BTV-8 strain demonstrated a high incidence of transplacental transmission in natural circumstances. The relevance of transplacental transmission for the epizootiology is considered limited, especially in enzootic areas. However, transplacental transmission can have a substantial economic impact due to the loss of progeny. Inactivated vaccines have demonstrated to prevent transplacental transmission. Vector-free horizontal transmission has also been demonstrated. Since direct horizontal transmission requires close contact of animals, it is considered only relevant for within-farm spreading of BTV. The genetic determinants which enable vector-free transmission are present in virus strains circulating in the field. More research into the genetic changes which enable vector-free transmission is essential to better evaluate the risks associated with outbreaks of new BTV serotypes and to design more appropriate control measures.

  2. Experimental transmission of atypical scrapie to sheep

    Directory of Open Access Journals (Sweden)

    Spiropoulos John

    2007-08-01

    Full Text Available Abstract Background Active surveillance for transmissible spongiform encephalopathies in small ruminants has been an EU regulatory requirement since 2002. A number of European countries have subsequently reported cases of atypical scrapie, similar to previously published cases from Norway, which have pathological and molecular features distinct from classical scrapie. Most cases have occurred singly in flocks, associated with genotypes considered to be more resistant to classical disease. Experimental transmissibility of such isolates has been reported in certain ovinised transgenic mice, but has not previously been reported in the natural host. Information on the transmissibility of this agent is vital to ensuring that disease control measures are effective and proportionate. Results This report presents the successful experimental transmission, in 378 days, of atypical scrapie to a recipient sheep of homologous genotype with preservation of the pathological and molecular characteristics of the donor. This isolate also transmitted to ovinised transgenic mice (Tg338 with a murine phenotype indistinguishable from that of Nor 98. Conclusion This result strengthens the opinion that these cases result from a distinct strain of scrapie agent, which is potentially transmissible in the natural host under field conditions.

  3. 10-year development statement on GRTgaz's transmission system 2009-2018

    International Nuclear Information System (INIS)

    2009-10-01

    GRTgaz is a European leader in natural gas transmission, a world expert in gas transmission networks and systems, and an operator firmly committed to the energy transition. It owns and operates the gas transmission network throughout most of France and it manages the transmission network in Germany, thereby helping to ensure correct operation of the French and European gas market. It contributes to the energy security of regional supply systems and performs a public service mission to ensure the continuity of consumer supply. The fourth Development Statement, covering the development of GRTgaz's transmission system over the period 2009-2018, reflects the sustained demand for new transmission capacity. If the connection projects (LNG terminals, combined-cycle gas turbine power stations, etc.) are confirmed, GRTgaz will pursue the expansion of its transmission infrastructures (1,600 km of additional pipelines, upgrading of the compressor fleet) and, in the long run, increase its entry and exit capacity by more than 65%. These investments will contribute to the opening up of the natural gas market, encouraged by the European Commission and already reinforced by the undertakings made to facilitate access to the French natural gas market. By providing tailored solutions and commercial tools, GRTgaz is making natural gas trading more fluid and enabling suppliers to improve their supplies for the benefit of consumers. Over the first six months of 2009, the number of wholesale market transactions in GRTgaz's North zone grew by more than 40% and the volumes traded by 70%, compared with the levels recorded over the same period in 2008. Since 2008, GRTgaz has seen a rise in demand for additional capacity on its transmission system, despite the slowdown in economic activity. The likelihood of projects being implemented in GRTgaz's North zone rose in 2009. A consultation of market players at the end of 2008 revealed very significant need for the development of

  4. Quadratic reactivity fuel cycle model

    International Nuclear Information System (INIS)

    Lewins, J.D.

    1985-01-01

    For educational purposes it is highly desirable to provide simple yet realistic models for fuel cycle and fuel economy. In particular, a lumped model without recourse to detailed spatial calculations would be very helpful in providing the student with a proper understanding of the purposes of fuel cycle calculations. A teaching model for fuel cycle studies based on a lumped model assuming the summability of partial reactivities with a linear dependence of reactivity usefully illustrates fuel utilization concepts. The linear burnup model does not satisfactorily represent natural enrichment reactors. A better model, showing the trend of initial plutonium production before subsequent fuel burnup and fission product generation, is a quadratic fit. The study of M-batch cycles, reloading 1/Mth of the core at end of cycle, is now complicated by nonlinear equations. A complete account of the asymptotic cycle for any order of M-batch refueling can be given and compared with the linear model. A complete account of the transient cycle can be obtained readily in the two-batch model and this exact solution would be useful in verifying numerical marching models. It is convenient to treat the parabolic fit rho = 1 - tau 2 as a special case of the general quadratic fit rho = 1 - C/sub tau/ - (1 - C)tau 2 in suitably normalized reactivity and cycle time units. The parabolic results are given in this paper

  5. Carbon cycle

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, J; Halbritter, G; Neumann-Hauf, G

    1982-05-01

    This report contains a review of literature on the subjects of the carbon cycle, the increase of the atmospheric CO/sub 2/ concentration and the possible impacts of an increased CO/sub 2/ concentration on the climate. In addition to this survey, the report discusses the questions that are still open and the resulting research needs. During the last twenty years a continual increase of the atmospheric carbon dioxide concentration by about 1-2 ppm per years has been observed. In 1958 the concentration was 315 ppm and this increased to 336 ppm in 1978. A rough estimate shows that the increase of the atmospheric carbon dioxide concentration is about half of the amount of carbon dioxide added to the atmosphere by the combustion of fossil fuels. Two possible sinks for the CO/sub 2/ released into the atmosphere are known: the ocean and the biota. The role of the biota is, however, unclear, since it can act both as a sink and as a source. Most models of the carbon cycle are one-dimensional and cannot be used for accurate predictions. Calculations with climate models have shown that an increased atmospheric CO/sub 2/ concentration leads to a warming of the earth's surface and lower atmosphere. Calculations show that a doubling of the atmospheric CO/sub 2/-concentration would lead to a net heating of the lower atmosphere and earth's surface by a global average of about 4 W m/sup -2/. Greater uncertainties arise in estimating the change in surface temperature resulting from this change in heating rate. It is estimated that the global average annual surface temperature would change between 1.5 and 4.5 K. There are, however, latitudinal and seasonal variations of the impact of increased CO/sub 2/ concentration. Other meteorological variables (e.g. precipitation, wind speed etc.) would also be changed. It appears that the impacts of the other products of fossil fuel combustion are unlikely to counteract the impacts of CO/sub 2/ on the climate.

  6. 75 FR 33296 - Columbia Gulf Transmission Company; Notice of Filing

    Science.gov (United States)

    2010-06-11

    ... Transmission Company; Notice of Filing June 2, 2010. Take notice that on May 20, 2010, Columbia Gulf..., pursuant to section 7(c) of the Natural Gas Act (NGA), for a certificate of public convenience and... of its existing transmission system to transport unprocessed gas (wet gas) near Centerville...

  7. 78 FR 43874 - Texas Eastern Transmission, LP; Notice of Application

    Science.gov (United States)

    2013-07-22

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP13-514-000] Texas Eastern Transmission, LP; Notice of Application On July 2, 2013, Texas Eastern Transmission, LP (Texas Eastern) filed... natural gas facilities no longer in service. As described more fully in the Application, Texas Eastern...

  8. The paradox of transmission system value

    International Nuclear Information System (INIS)

    Haddad, S.Z.; Feldman, R.D.; Charnetzki, P.

    1995-01-01

    The central importance of utility strategic planning with respect to transmission systems has developed as a result of the passage of the Energy Policy Act and the rapid emergence of the era of open grid access. As a consequence, utilities have had to redefine transmission as being more than a cost center managed with reliability as the principal focus and regulated on a rate of return basis. Transmission must now be managed with a view to protection of customers, where possible, and to revenue maximization, both through pricing strategy and through operations. This shift has been compounded by the pressures being thrust upon utilities by regulators or being fomented by competitors to unbundle transmission and distribution from generation. This paper explores how the value of the transmission system can be viewed from the vantage points of different organizations (utilities, regulators, customers, independent generators, etc.). The paper addresses the uncertain and apparently paradoxical nature of transmission system value as it will be impacted by the possible alternative future structures of the electric power industry. Lastly, this paper suggests the strategic possibilities for utilities that this uncertainty presents

  9. Your Menstrual Cycle

    Science.gov (United States)

    ... your menstrual cycle What happens during your menstrual cycle The menstrual cycle includes not just your period, but the rise ... that take place over the weeks in your cycle. Want to know what happens on each day ...

  10. Transmission pipeline calculations and simulations manual

    CERN Document Server

    Menon, E Shashi

    2014-01-01

    Transmission Pipeline Calculations and Simulations Manual is a valuable time- and money-saving tool to quickly pinpoint the essential formulae, equations, and calculations needed for transmission pipeline routing and construction decisions. The manual's three-part treatment starts with gas and petroleum data tables, followed by self-contained chapters concerning applications. Case studies at the end of each chapter provide practical experience for problem solving. Topics in this book include pressure and temperature profile of natural gas pipelines, how to size pipelines for specified f

  11. Transmission line capital costs

    International Nuclear Information System (INIS)

    Hughes, K.R.; Brown, D.R.

    1995-05-01

    The displacement or deferral of conventional AC transmission line installation is a key benefit associated with several technologies being developed with the support of the U.S. Department of Energy's Office of Energy Management (OEM). Previous benefits assessments conducted within OEM have been based on significantly different assumptions for the average cost per mile of AC transmission line. In response to this uncertainty, an investigation of transmission line capital cost data was initiated. The objective of this study was to develop a database for preparing preliminary estimates of transmission line costs. An extensive search of potential data sources identified databases maintained by the Bonneville Power Administration (BPA) and the Western Area Power Administration (WAPA) as superior sources of transmission line cost data. The BPA and WAPA data were adjusted to a common basis and combined together. The composite database covers voltage levels from 13.8 to 765 W, with cost estimates for a given voltage level varying depending on conductor size, tower material type, tower frame type, and number of circuits. Reported transmission line costs vary significantly, even for a given voltage level. This can usually be explained by variation in the design factors noted above and variation in environmental and land (right-of-way) costs, which are extremely site-specific. Cost estimates prepared from the composite database were compared to cost data collected by the Federal Energy Regulatory Commission (FERC) for investor-owned utilities from across the United States. The comparison was hampered because the only design specifications included with the FERC data were voltage level and line length. Working within this limitation, the FERC data were not found to differ significantly from the composite database. Therefore, the composite database was judged to be a reasonable proxy for estimating national average costs

  12. Transmission positron microscopes

    International Nuclear Information System (INIS)

    Doyama, Masao; Kogure, Yoshiaki; Inoue, Miyoshi; Kurihara, Toshikazu; Yoshiie, Toshimasa; Oshima, Ryuichiro; Matsuya, Miyuki

    2006-01-01

    Immediate and near-future plans for transmission positron microscopes being built at KEK, Tsukuba, Japan, are described. The characteristic feature of this project is remolding a commercial electron microscope to a positron microscope. A point source of electrons kept at a negative high voltage is changed to a point source of positrons kept at a high positive voltage. Positional resolution of transmission microscopes should be theoretically the same as electron microscopes. Positron microscopes utilizing trapping of positrons have always positional ambiguity due to the diffusion of positrons

  13. ETR transmission systems

    International Nuclear Information System (INIS)

    Metzler, D.

    1983-01-01

    The presentation concentrates on factors associated with transmission systems for reactors and/or reactor relevant devices. For present day mirrors and their upgrades where power levels are in the few hundred kW range, waveguide systems with mode control are preferred. Beyond the early 1990's time frame are the ETR DEMO and reactor devices. These require injected power levels of about 75 MW. If only power oscillators are available at that time, then a MARS like transmission system may be appropriate or possibly a guided wave waveguide

  14. Transmission grid security

    CERN Document Server

    Haarla, Liisa; Hirvonen, Ritva; Labeau, Pierre-Etienne

    2011-01-01

    In response to the growing importance of power system security and reliability, ""Transmission Grid Security"" proposes a systematic and probabilistic approach for transmission grid security analysis. The analysis presented uses probabilistic safety assessment (PSA) and takes into account the power system dynamics after severe faults. In the method shown in this book the power system states (stable, not stable, system breakdown, etc.) are connected with the substation reliability model. In this way it is possible to: estimate the system-wide consequences of grid faults; identify a chain of eve

  15. Polish Standard of the Technical Safety of Transmission Gas Pipelines

    International Nuclear Information System (INIS)

    Tkacz, A.J.

    2006-01-01

    The document is presenting the idea of the CNGI Norm called The Polish Standard of the Technical Safety of Transmission Gas Pipelines and the way of using it by companies associated in the Chamber of the Natural Gas Industry in the business activity. It will be applied to improve the quality and reliability of gas transmission after full opening of Polish natural gas market. (author)

  16. Climate Variability, Social and Environmental Factors, and Ross River Virus Transmission: Research Development and Future Research Needs

    Science.gov (United States)

    Tong, Shilu; Dale, Pat; Nicholls, Neville; Mackenzie, John S.; Wolff, Rodney; McMichael, Anthony J.

    2008-01-01

    Background Arbovirus diseases have emerged as a global public health concern. However, the impact of climatic, social, and environmental variability on the transmission of arbovirus diseases remains to be determined. Objective Our goal for this study was to provide an overview of research development and future research directions about the interrelationship between climate variability, social and environmental factors, and the transmission of Ross River virus (RRV), the most common and widespread arbovirus disease in Australia. Methods We conducted a systematic literature search on climatic, social, and environmental factors and RRV disease. Potentially relevant studies were identified from a series of electronic searches. Results The body of evidence revealed that the transmission cycles of RRV disease appear to be sensitive to climate and tidal variability. Rainfall, temperature, and high tides were among major determinants of the transmission of RRV disease at the macro level. However, the nature and magnitude of the interrelationship between climate variability, mosquito density, and the transmission of RRV disease varied with geographic area and socioenvironmental condition. Projected anthropogenic global climatic change may result in an increase in RRV infections, and the key determinants of RRV transmission we have identified here may be useful in the development of an early warning system. Conclusions The analysis indicates that there is a complex relationship between climate variability, social and environmental factors, and RRV transmission. Different strategies may be needed for the control and prevention of RRV disease at different levels. These research findings could be used as an additional tool to support decision making in disease control/surveillance and risk management. PMID:19079707

  17. Wildlife and electric power transmission

    Science.gov (United States)

    Ellis, D.H.; Goodwin, J.G.; Hunt, J.R.; Fletcher, John L.; Busnel, R.G.

    1978-01-01

    Hundreds of thousands of miles of transmission lines have been introduced into our natural environment. These lines and their corridors can be damaging or beneficial to wildlife communities depending on how they are designed, where they are placed, and when they are constructed and maintained. With the current trend toward UHV systems, new problems (associated with additional increments in audible noise, electric and magnetic force fields, etc.) must be addressed. We recommend the following areas for careful study: (1) the response of wilderness species to transmission lines and line construction and maintenance activities (2) the magnitude of bird collision and electrocution mortality, (3) the response of power corridor and power tower in habiting wildlife to laboratory and field doses of electro-chemical oxidants, corona noise, electric and magnetic fields, etc., (4) the productivity of tower inhabiting birds compared with nearby non-tower nesters, and (5) the influence of powerline corridors on mammalian and avian migration patterns. It is our hope that the questions identified in this study will help stimulate further research so that we can maximize wildlife benefits and minimize wildlife detriments.

  18. Information transmission on hybrid networks

    Science.gov (United States)

    Chen, Rongbin; Cui, Wei; Pu, Cunlai; Li, Jie; Ji, Bo; Gakis, Konstantinos; Pardalos, Panos M.

    2018-01-01

    Many real-world communication networks often have hybrid nature with both fixed nodes and moving modes, such as the mobile phone networks mainly composed of fixed base stations and mobile phones. In this paper, we discuss the information transmission process on the hybrid networks with both fixed and mobile nodes. The fixed nodes (base stations) are connected as a spatial lattice on the plane forming the information-carrying backbone, while the mobile nodes (users), which are the sources and destinations of information packets, connect to their current nearest fixed nodes respectively to deliver and receive information packets. We observe the phase transition of traffic load in the hybrid network when the packet generation rate goes from below and then above a critical value, which measures the network capacity of packets delivery. We obtain the optimal speed of moving nodes leading to the maximum network capacity. We further improve the network capacity by rewiring the fixed nodes and by considering the current load of fixed nodes during packets transmission. Our purpose is to optimize the network capacity of hybrid networks from the perspective of network science, and provide some insights for the construction of future communication infrastructures.

  19. Evaluation of a system of refrigeration with absorption cycle using the direct burning of natural gas for tropical fruits storage; Avaliacao de um sistema de refrigeracao com ciclo de absorcao utilizando a queima direta de gas natural para armazenamento de frutas tropicais

    Energy Technology Data Exchange (ETDEWEB)

    Bartolomeu, Lair S.; Torres, Ednildo A. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Lab. de Energia e Gas; Silva, Gabriel F. [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil); Martins, Ronaldo M. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Materiais. CQDM; Campos, Michel F. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Gerencia de Tecnologia do Gas Natural. Rede GasEnergia

    2004-07-01

    This work has the purpose to analyze an alternative method in the conservation of tropical fruits in chamber cooled through the technology of use of the natural gas as energy source. The study it was carried through in chiller of absorption, Robur model, of 5TR, which meets in the campus of the Federal University of Sergipe (UFS/LEG). The energy analysis had as objective to study the process involving the cycle and its components. Of the analysis of first law was gotten a power of refrigeration of 8,8 kW and a COP=0,32 and the analysis of second law {beta}=0,29. The exergetic analysis had for intention to evaluate the amount and the quality of the energy in the system. The heat generator was the component that presented the biggest irreversibility, whose relation with the total irreversibility was about 70%. In the absorber the lesser exergetic efficiency was verified. Project is supported by the GasEnergia/PETROBRAS. (author)

  20. Evaluating the travel, physical activity and carbon impacts of a ?natural experiment? in the provision of new walking and cycling infrastructure: methods for the core module of the iConnect study

    OpenAIRE

    Ogilvie, David; Bull, Fiona; Cooper, Ashley; Rutter, Harry; Adams, Emma; Brand, Christian; Ghali, Karen; Jones, Tim; Mutrie, Nanette; Powell, Jane; Preston, John; Sahlqvist, Shannon; Song, Yena

    2012-01-01

    Article summary Article focus Walking and cycling offer an ideal opportunity for people to incorporate more moderate-intensity physical activity into their daily lives, thereby reducing their risk of chronic diseases such as diabetes and coronary heart disease. Improving infrastructure to support walking and cycling is often regarded as fundamental to encouraging their widespread uptake, but there is little robust evidence to support the effectiveness of this type of intervention. Connect2 is...