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Sample records for included nevirapine trough

  1. Nevirapine

    Science.gov (United States)

    ... HIV in the blood. Although nevirapine does not cure HIV, it may decrease your chance of developing acquired ... you get your full dose.Nevirapine may control HIV but will not cure it. Continue to take nevirapine even if you ...

  2. Genotypic and phenotypic nevirapine resistance correlates with virological failure during salvage therapy including abacavir and nevirapine

    DEFF Research Database (Denmark)

    Jørgensen, L.B.; Katzenstein, T.L.; Gerstoft, J.

    2000-01-01

    OBJECTIVE: To study the development of resistance during 8 weeks of salvage therapy with abacavir and nevirapine in combination with other reverse transcriptase inhibitors (RTIs) and protease inhibitors (PIs). METHODS: Samples obtained at baseline and after 8 weeks of therapy from 16 heavily...... and after 2, 4 and 8 weeks of therapy. RESULTS: The majority of patients was genotypically and phenotypically resistant to lamivudine, abacavir, zidovudine and PIs, whereas 50% of the patients showed resistance to nevirapine at baseline in at least one of the methods used. After 8 weeks of salvage therapy...... higher transient reduction in viral load was observed in patients with nevirapine-sensitive HIV at baseline compared to patients with resistant HIV at baseline. CONCLUSION: The transient effect of salvage therapy including abacavir and nevirapine was due to the effect of nevirapine. The lack of effect...

  3. Sub-therapeutic nevirapine concentration during antiretroviral treatment initiation among children living with HIV: Implications for therapeutic drug monitoring.

    Directory of Open Access Journals (Sweden)

    Bindu Parachalil Gopalan

    Full Text Available Nevirapine, a component of antiretroviral therapy (ART in resource-limited settings, known for auto-induction of metabolism, is initiated at half therapeutic dose until day 14 ('lead-in period', and subsequently escalated to full dose. However, studies have shown that this dosing strategy based on adult studies may not be appropriate in children, given that younger children have higher drug clearance rates. In this prospective cohort study, we studied trough plasma nevirapine levels by high performance liquid chromatography (HPLC at days 7, 14 (lead-in period and 28 (full dose period after ART initiation amongst HIV-1 infected children initiating nevirapine-based ART in southern India. Among the 20 children (50% male, median age 9 years included in the study, sub-therapeutic trough plasma nevirapine concentration (<4μg/ml was seen in 65% (13/20 of children during the lead-in period within two weeks of ART initiation and among 10% of children at 4 weeks during full-dose nevirapine. Adherence was documented as ≥95% in all children by both caregiver self-report and pill count. Median nevirapine concentrations achieved at week 1 was 4.8 μg/ml, significantly lower than 8 μg/ml, the concentration achieved at week 4 (p = 0.034. Virological failure at one year of ART was observed in six children, and was not associated with median nevirapine concentration achieved during week 1, 2 or 4. We conclude that the dose escalation strategy currently practiced among young children living with HIV-1 resulted in significant subtherapeutic nevirapine concentration (≤4μg/ml during the lead-in period. We call for a closer look at pediatric-focused dosing strategies for nevirapine initiation in young children. Further studies to establish age-appropriate threshold nevirapine concentration are warranted in young children to corroborate the role of therapeutic drug monitoring in predicting virological outcome.

  4. The antiretroviral efficacy of highly active antiretroviral therapy and plasma nevirapine concentrations in HIV-TB co-infected Indian patients receiving rifampicin based antituberculosis treatment

    Directory of Open Access Journals (Sweden)

    Sinha Sanjeev

    2011-11-01

    Full Text Available Abstract Background Rifampicin reduces the plasma concentrations of nevirapine in human immunodeficiency virus (HIV and tuberculosis (TB co-infected patients, who are administered these drugs concomitantly. We conducted a prospective interventional study to assess the efficacy of nevirapine-containing highly active antiretroviral treatment (HAART when co-administered with rifampicin-containing antituberculosis treatment (ATT and also measured plasma nevirapine concentrations in patients receiving such a nevirapine-containing HAART regimen. Methods 63 cases included antiretroviral treatment naïve HIV-TB co-infected patients with CD4 counts less than 200 cells/mm3 started on rifampicin-containing ATT followed by nevirapine-containing HAART. In control group we included 51 HIV patients without tuberculosis and on nevirapine-containing HAART. They were assessed for clinical and immunological response at the end of 24 and 48 weeks. Plasma nevirapine concentrations were measured at days 14, 28, 42 and 180 of starting HAART. Results 97 out of 114 (85.1% patients were alive at the end of 48 weeks. The CD4 cell count showed a mean increase of 108 vs.113 cells/mm3 (p=0.83 at 24 weeks of HAART in cases and controls respectively. Overall, 58.73% patients in cases had viral loads of less than 400 copies/ml at the end of 48 weeks. The mean (± SD Nevirapine concentrations of cases and control at 14, 28, 42 and 180 days were 2.19 ± 1.49 vs. 3.27 ± 4.95 (p = 0.10, 2.78 ± 1.60 vs. 3.67 ± 3.59 (p = 0.08, 3.06 ± 3.32 vs. 4.04 ± 2.55 (p = 0.10 respectively and 3.04 μg/ml (in cases. Conclusions Good immunological and clinical response can be obtained in HIV-TB co-infected patients receiving rifampicin and nevirapine concomitantly despite somewhat lower nevirapine trough concentrations. This suggests that rifampicin-containing ATT may be co administered in resource limited setting with nevirapine-containing HAART regimen without substantial reduction in

  5. [Hepatotoxicity in healthy infants exposed to nevirapine during pregnancy].

    Science.gov (United States)

    Iveli, Pablo; Noguera-Julian, Antoni; Soler-Palacín, Pere; Martín-Nalda, Andrea; Rovira-Girabal, Núria; Fortuny-Guasch, Clàudia; Figueras-Nadal, Concepció

    2016-01-01

    The use of nevirapine in HIV-infected pregnant women is discouraged due to its potential to cause hepatotoxicity. There is limited information available on the toxicity in non-HIV infected newborn exposed to this drug during pregnancy. The aim of the study is to determine the extent of hepatotoxicity in the newborn exposed to nevirapine and HIV during pregnancy. A cross-sectional, observational, multicenter study was conducted on a cohort of healthy infants born to HIV-infected mothers, in whom the first determination of alanine aminotransferase (ALT), before 6weeks of age, was collected. Patients were allocated to 2groups according to exposure to nevirapine during pregnancy. Hepatotoxicity was rated according to the AIDS Table for Grading the Severity of Adult and Pediatric Adverse Events (DAIDS). This study included 160newborns from 159pregnancies (88exposed to nevirapine-based regimens and 71 exposed to protease inhibitors-based therapies). No cases of hepatotoxicity were observed according to the DAIDS Table for Grading. Two cases of ALT above normal values (2.8%; 95%CI: 0.3-9.8%) were observed in patients not exposed to nevirapine, and one case (1.1%; 95%CI: 0.0-6.1%) in the group exposed to nevirapine (P=.585). The lack of differences between groups suggests that highly active antiretroviral treatment regimens including nevirapine administered during pregnancy do not involve a higher risk of liver disease compared to other treatment combinations. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  6. Preparation and characterisation of nevirapine oral nanosuspensions.

    Science.gov (United States)

    Raju, Anju; Reddy, A Jagdeesh; Satheesh, J; Jithan, A V

    2014-01-01

    The objective of this study was to prepare and characterise nevirapine nanosuspensions so as to improve the dissolution rate of nevirapine. Nevirapine is a nonnucleoside reverse transcriptase inhibitor of immunodeficiency virus type-1 and it is poorly water-soluble antiretroviral drug. The low solubility of nevirapine can lead to decreased and variable oral bioavailability. Nanosuspension can overcome the oral bioavailability problem of nevirapine. Nevirapine nanosuspensions were prepared using nanoedge method. The suspensions were stabilised using surfactants Lutrol F 127 or Poloxamer 407 and hydroxypropyl methyl cellulose. The nanosuspension was characterised for particle size, polydispersibility index, crystalline state, particle morphology, in vitro drug release and pharmacokinetics in rats after oral administration. The results support the claim for the preparation of nanosuspensions with enhanced solubility and bioavailability.

  7. RESEARCH Safety of nevirapine in HIV-infected pregnant women ...

    African Journals Online (AJOL)

    (FDA) issued a public health advisory recommending against initiating nevirapine (NVP) in HIV-infected women (including pregnant women) with CD4 counts >250 cells/µl.1 The NVP package insert was revised accordingly to warn about risks, with further revision in November 2011 to comply with FDA recommendations.

  8. Safety of nevirapine in HIV-infected pregnant women initiating ...

    African Journals Online (AJOL)

    Background. The package insert for nevirapine (NVP) cautions against use in HIV-infected women (including pregnant women) with CD4 counts .250 cells/ƒÊl. However, recent studies showed that the CD4 count of pregnant women receiving antiretroviral therapy (ART) was not predictive of NVP toxicity. Objectives.

  9. ORIGINAL ARTICLES Nevirapine toxicity- implications for ...

    African Journals Online (AJOL)

    maternal and fetal health. Nevirapine is an FDA category C drug, indicating no teratogenicity in animal studies but a lack of well-controlled trials in pregnant women. .... of liver function tests and increased clinical vigilance is required to identify hypersensitivity reactions, consisting of elevated hepatic enzymes with rash and/ ...

  10. Trough for piglets

    DEFF Research Database (Denmark)

    2006-01-01

    A trough is disclosed for supplying piglets with mineral supplements in the suckling period. The trough is designed to awaken the piglets' curiosity and thus make them root in the bottom of the trough, where the mineral supplements are dispensed in form of a dry powder mixture, and thus reduce...... spillage as compared to placing the mineral supplements on the floor of the pen. During the pre-weaning of the piglets the trough can be converted to serve as a normal trough for solid feed....

  11. Nevirapine Pharmacokinetics and Safety in Neonates Receiving Combination Antiretroviral Therapy for Prevention of Vertical HIV Transmission.

    Science.gov (United States)

    Lau, Elaine; Brophy, Jason; Samson, Lindy; Kakkar, Fatima; Campbell, Douglas M; Yudin, Mark H; Murphy, Kellie; Seto, Winnie; Colantonio, David; Read, Stanley E; Bitnun, Ari

    2017-04-15

    Nevirapine (NVP)-based combination antiretroviral therapy is routinely prescribed to infants deemed at high risk of vertical HIV infection in our centers. We evaluated NVP pharmacokinetics and safety of this regimen. Neonates were recruited prospectively between September 2012 and April 2015 or enrolled retrospectively if treated similarly before prospective study initiation. NVP was dosed at 150 mg/m daily for 14 days, then twice daily for 14 days. NVP levels were drawn at weeks 1, 2, and 4 [target trough (NVP-T): 3-8 mg/L]. Thirty-three neonates were included (23 prospectively). Median gestational age (GA) and birth weight were 38 weeks (32-41 weeks) and 2.9 kg (1.5-4.2 kg), respectively. Median NVP-Ts were 8.2 mg/L (1.6-25.1 mg/L), 3.5 mg/L (1.6-6.8 mg/L), and 4.3 mg/L (0.1-19.9 mg/L) at weeks 1, 2, and 4, respectively. The proportions with therapeutic NVP-T were 42%, 61%, and 73% at these same timepoints. Median apparent oral clearance (CL/F) increased from 0.05 L·kg·h (0.01-0.50 L·kg·h) at week 2 to 0.18 L·kg·h (0.01-0.78 L·kg·h) at week 4. Increased drug exposure [area under the curve (AUCτ)] correlated with younger GA (r = 0.459, P = 0.032) and lower birth weight (r = 0.542, P = 0.009). The most common adverse events potentially attributable to combination antiretroviral therapy were transient asymptomatic hyperlactatemia (26%), anemia (24.7%), and neutropenia (22.1%). Treatment dose NVP was generally well-tolerated and associated with normalization of trough levels over time in most cases without dose adjustment. Lower empiric dosing is recommended for infants <34 weeks of GA. Routine therapeutic drug monitoring may not be required for infants ≥34 weeks of GA.

  12. Solar photovoltaic reflective trough collection structure

    Science.gov (United States)

    Anderson, Benjamin J.; Sweatt, William C.; Okandan, Murat; Nielson, Gregory N.

    2015-11-19

    A photovoltaic (PV) solar concentration structure having at least two troughs encapsulated in a rectangular parallelepiped optical plastic structure, with the troughs filled with an optical plastic material, the troughs each having a reflective internal surface and approximately parabolic geometry, and the troughs each including photovoltaic cells situated so that light impinging on the optical plastic material will be concentrated onto the photovoltaic cells. Multiple structures can be connected to provide a solar photovoltaic collection system that provides portable, efficient, low-cost electrical power.

  13. Incidence and determinants of nevirapine and efavirenz-related skin rashes in West Africans: nevirapine's epitaph?

    Directory of Open Access Journals (Sweden)

    Fred Stephen Sarfo

    Full Text Available Non-nucleoside reverse transcriptase inhibitor (NNRTI associated rash is common and frequently leads to discontinuation of NNRTIs. This study assessed the risk of developing rashes and discontinuing NNRTIs and associated factors in a large clinic in central Ghana. In this retrospective cohort study, clinical data were obtained in patients starting efavirenz or nevirapine between 2004-2010. Factors associated with rashes were explored using a multivariate Cox proportional hazards regression model. Of 3,999 patients who started NNRTI-based ART, 281 (7.0% experienced at least one episode of NNRTI-related rash with an incidence of 2.63 events/100 person-years, occurring in 10.2% and 5.6% of patients taking nevirapine and efavirenz respectively. Most rashes (94% were grade 1 or 2 and were reported a median of 2 months following initiation of ART. In multivariate analysis developing a rash was associated with nevirapine use (aHR 1.67, 95% CI 1.28-2.10, female gender (aHR of 1.39, 95% CI 1.01-1.92 and lower baseline CD4 counts (aHR 0.88, 95% CI 0.82-0.95 per 50 cells/mm³ increment. Patients with nevirapine-associated rash were 11 times more likely to discontinue treatment as patients with efavirenz-associated rash. In contrast to findings in other studies, NNRTI-associated rashes in Ghanaians appear more common in patients with lower baseline CD4 counts. Given the increased frequency of rashes with nevirapine and subsequent discontinuations in many patients, along with other treatment-limiting toxicities, this provides further impetus for the replacement of nevirapine by efavirenz as the first-line NNRTI treatment of choice in Africa.

  14. Incidence of nevirapine-associated hepatitis in an antenatal clinic

    African Journals Online (AJOL)

    2008-01-22

    Jan 22, 2008 ... together with a non-nucleoside reverse transcriptase inhibitor, either efavirenz or nevirapine.1 As efavirenz is thought to be a teratogen and is classified as a Food and Drug Administration. (FDA) category D drug, nevirapine is the preferred agent for use in pregnant women, for women planning a pregnancy ...

  15. a study of nevirapine toxicity in hiv infected pregnant women

    African Journals Online (AJOL)

    Esem

    J M Mulindwa. Department of Obstetrics and Gynaecology, University Teaching Hospital. ABSTRACT. Objective: The general objective of the study was to determine incidence of nevirapine toxicity in pregnant. HIV infected women commenced on nevirapine-based regimen in the current pregnancy with CD4 counts up to. 3.

  16. Therapeutic drug monitoring of nevirapine in resource-limited settings.

    NARCIS (Netherlands)

    L'homme, R.F.A.; Muro, E.P.; Droste, J.A.H.; Wolters, L.R.; Ewijk-Beneken Kolmer, E.W.J. van; Schimana, W.; Burger, D.M.

    2008-01-01

    BACKGROUND: We developed a simple and inexpensive thin-layer chromatography (TLC) assay for semiquantitative detection of saliva concentrations of nevirapine in resource-limited settings. The method was validated in an African target population. METHODS: Paired plasma and saliva nevirapine

  17. 2'-Deoxythymidine Adducts from the Anti-HIV Drug Nevirapine

    Directory of Open Access Journals (Sweden)

    M. Matilde Marques

    2013-04-01

    Full Text Available Nevirapine (NVP is a non-nucleoside reverse transcriptase inhibitor (NNRTI used against HIV-1. Currently, NVP is the most widely used anti-HIV drug in developing countries, both in combination therapy and to prevent mother-to-child transmission of HIV. Despite its efficacy against HIV, NVP produces a variety of toxic responses, including hepatotoxicity and skin rash. It is also associated with increased incidences of hepatoneoplasias in rodents. In addition, epidemiological data suggest that NNRTI use is a risk factor for non-AIDS-defining cancers in HIV-positive patients. Current evidence supports the involvement of metabolic activation to reactive electrophiles in NVP toxicity. NVP metabolism includes oxidation to 12-hydroxy-NVP; subsequent Phase II sulfonation produces an electrophilic metabolite, 12-sulfoxy-NVP, capable of reacting with DNA to yield covalent adducts. Since 2’-deoxythymidine (dT adducts from several alkylating agents are regarded as having significant mutagenic/carcinogenic potential, we investigated the formation of NVP-dT adducts under biomimetic conditions. Toward this goal, we initially prepared and characterized synthetic NVP-dT adduct standards using a palladium-mediated Buchwald-Hartwig coupling strategy. The synthetic standards enabled the identification, by LC-ESI-MS, of 12-(2'-deoxythymidin-N3-yl-nevirapine (N3-NVP-dT in the enzymatic hydrolysate of salmon testis DNA reacted with 12-mesyloxy-NVP, a synthetic surrogate for 12-sulfoxy-NVP. N3-NVP-dT, a potentially cytotoxic and mutagenic DNA lesion, was also the only dT-specific adduct detected upon reaction of dT with 12-mesyloxy-NVP. Our data suggest that N3-NVP-dT may be formed in vivo and play a role in the hepatotoxicity and/or putative hepatocarcinogenicity of NVP.

  18. Development of a liposomal nanodelivery system for nevirapine

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    Krishnan Uma M

    2010-07-01

    Full Text Available Abstract Background The treatment of AIDS remains a serious challenge owing to high genetic variation of Human Immunodeficiency Virus type 1 (HIV-1. The use of different antiretroviral drugs (ARV is significantly limited by severe side-effects that further compromise the quality of life of the AIDS patient. In the present study, we have evaluated a liposome system for the delivery of nevirapine, a hydrophobic non-nucleoside reverse transcriptase inhibitor. Liposomes were prepared from egg phospholipids using thin film hydration. The parameters of the process were optimized to obtain spherical liposomes below 200 nm with a narrow polydispersity. The encapsulation efficiency of the liposomes was optimized at different ratios of egg phospholipid to cholesterol as well as drug to total lipid. The data demonstrate that encapsulation efficiency of 78.14% and 76.25% were obtained at egg phospholipid to cholesterol ratio of 9:1 and drug to lipid ratio of 1:5, respectively. We further observed that the size of the liposomes and the encapsulation efficiency of the drug increased concomitantly with the increasing ratio of drug and lipid and that maximum stability was observed at the physiological pH. Thermal analysis of the drug encapsulated liposomes indicated the formation of a homogenous drug-lipid system. The magnitude of drug release from the liposomes was examined under different experimental conditions including in phosphate buffered saline (PBS, Dulbecco's Modified Eagle's Medium (DMEM supplemented with 10% fetal bovine serum or in the presence of an external stimulus such as low frequency ultrasound. Within the first 20 minutes 40, 60 and 100% of the drug was released when placed in PBS, DMEM or when ultrasound was applied, respectively. We propose that nevirapine-loaded liposomal formulations reported here could improve targeted delivery of the anti-retroviral drugs to select compartments and cells and alleviate systemic toxic side effects as a

  19. Toxicogenomics of nevirapine-associated cutaneous and hepatic adverse events among populations of African, Asian, and European descent

    NARCIS (Netherlands)

    Yuan, Jing; Guo, Sheng; Hall, David; Cammett, Anna M.; Jayadev, Supriya; Distel, Manuel; Storfer, Stephen; Huang, Zimei; Mootsikapun, Piroon; Ruxrungtham, Kiat; Podzamczer, Daniel; Haas, David W.; Benetucci, Jorge; Ortega, Gerardo; Cahn, Pedro; Cesar, Carina; Cassetti, Isabel; Bissio, Emiliano; Lupo, Sergio; Chuah, John; Workman, Cassy; Rees, Vanessa; Cooper, David A.; Hickey, Rebecca; Anderson, Jonathan; Moore, Richard; Hoy, Jennifer; Downs, Cath; Finlayson, Robert; Bodsworth, Neil; Eu, Beng; Lau, Helen; Montaner, Julio; Harris, Marianne; Walmsley, Sharon; d'Aquila, Adrianna; Conway, Brian; Tossonian, Harout; Morlat, Philippe; Louis, Isabelle; Yazdanpanah, Yazdan; Ajana, Faiza; Bollens, Diane; Girard, Pierre-Marie; May, Thierry; Pialoux, Gilles; Slama, Laurence; Lyavanc, Thomas; Piketty, Christophe; Pluot, Christel; Cotte, Laurent; Miailhes, Patrick; Reliquet, Veronique; Raffi, François; Phung, Bao; Yeni, Patrick; Simon, Anne; Bonmarchand, Manuela; Ponscarme, Diane; Rozenbaum, Willy; Alvarez, Muriel; Marchou, Bruno; Plettenberg, Andreas; Stoehr, Albrecht; Rockstroh, Jürgen; Schwarze-Zander, Carolynne; Brockmeyer, Norbert H.; Klinker, Hartwig; Heinz, Werner; Hoffmann, Christian; Bergmann, Frank; Schuermann, Dirk; Lutz, Thomas; Gute, Peter; Arastéh, Keikawus; Hartikainen, Jukka; Rittweger, Michael; Kern, Peter; Härter, Georg; Reuter, Stefan; Jensen, Björn; Esser, Stefan; Jablonka, Robert; Morbach, Karin; Jaegel-Guedes, Eva; Reiss, Peter; van den Berk, Guido; Branger, Judith; Brinkman, Kees; Puig, Jordi; Negredo, Eugènia; Viciana, Pompeyo; Lopez-Cortes, Luis; de Los Santos, Ignacio; Sanz, Jesús; Mallolas, Josep; Laguno, Montserrat; Ribera, Esteban; Villar del Saz, Sara; Vergas, Jorge; Téllez, M. Jesús; López, Juan Carlos; Sanchez-Conde, Matilde; Domingo, Pere; Casado, José L.; Pumares, María; Lin, Hsi-Hsun; Liu, Yung-Ching; Wang, Yung-Hsing; Tsai, Hung-Chin; Wang, Jen-Hsien; Wong, Wing Wai; Hu, Bor-Shen; Hsieh, Szu-Min; Sheng, Wang-Huei; Lin, Yu-Hui; Lu, Po-Liang; Chen, Tun-Chieh; Avihingsanon, Anchalee; Anekthananon, Thanomsak; Ratanasuwan, Winai; Tawana, Cheryl; Limb, Simon; Vilar, Francisco Javier; Clowes, Yvonne; Barrett, Sarah; Taylor, Stephen; Allan, Sris; Barnes, Justine; Fisher, Martin; Perry, Nicky; Pozniak, Anton L.; Boffito, Marta; Sadiq, Tariq; Adebiyi, Ade; Davis, Charles; Redfield, Robert R.; Kozal, Michael J.; Andrews, Laurie; Miller, Mark; Johnston, Barbara; Savage, Karen; Saag, Michael; Grossman, Howard A.; Cohen, Daniel E.; Overton, Edgar Turner; Snell, Mariea B.; Burman, William; Britt, Dale; Martorell, Claudia; Rivera, Jacqueline; Eron, Joseph J.; Menezes, Prema

    2011-01-01

    Nevirapine is widely prescribed for HIV-1 infection. We characterized relationships between nevirapine-associated cutaneous and hepatic adverse events and genetic variants among HIV-infected adults. We retrospectively identified cases and controls. Cases experienced symptomatic nevirapine-associated

  20. Hepatic adverse events during highly active antiretroviral therapy containing nevirapine: a case report

    Directory of Open Access Journals (Sweden)

    Yamazhan Tansu

    2002-09-01

    Full Text Available Abstract Background Hepatotoxicity is one of the most serious complications of highly active antiretroviral therapy (HAART. The aim of this report is to analyse an HIV infected patient on HAART including nevirapine and taking antidepressive agents, with acute toxic hepatitis. Case presentation A 39 year old patient diagnosed as HIV positive one month ago administered to the clinical ward of the Department of Infectious Diseases and Clinical Microbiology in Ege University Medical School with high fever, malaise, nausea, diarrheae and elevated liver enzymes (ALT 1558 U/L, AST 4288 U/L. He has been using HAART including zidovudine+lamivudine (2 × 1/day and nevirapine (2 × 200 mg/day, following dose escalation for 22 days, sertralin and diazepam for 12 days and lithium for 10 days. The patient was hospitalized. Antiretroviral and antidepressant treatments were stopped. The day after admission, his fever dropped and his symptoms improved. Clinical improvement continued on the following days. The patient was discharged upon his request on the 14th day of hospitalization. The liver function tests returned to normal levels in two weeks following discharge. Conclusion Close monitoring of liver enzymes during the first 12 weeks of nevirapine therapy is critical to prevent life threatening events.

  1. Pharmacological and clinical evidence of nevirapine immediate- and extended-release formulations

    Directory of Open Access Journals (Sweden)

    Ena J

    2012-11-01

    Full Text Available Javier Ena, Concepción Amador, Conxa Benito, Francisco PasquauHIV Unit, Hospital Marina Baixa, Villajoyosa, SpainAbstract: We reviewed the current information available on nevirapine immediate- and extended-release formulations and its role in single-dose and combination antiretroviral therapy. Nevirapine was approved in 1996 and was the first non-nucleoside reverse-transcriptase inhibitor available for the treatment of HIV-1 infection. Nevirapine has demonstrated good efficacy and a well-characterized safety profile. A major drawback is the low genetic barrier, allowing the emergence of resistance in the presence of single mutations in the reverse-transcriptase gene. This shortcoming is particularly relevant when nevirapine is administered in a single dose to prevent mother-to-child transmission of HIV-1 infection, compromising the efficacy of future non-nucleoside reverse transcriptase–inhibitor regimens. Studies published recently have probed the noninferiority of nevirapine compared to ritonavir-boosted atazanavir with both tenofovir disoproxil fumarate and emtricitabine in antiretroviral treatment–naïve patients. In 2011, a new formulation of nevirapine (nevirapine extended release that allowed once-daily dosing was approved by the Food and Drug Administration and by the European Medicines Agency. VERxVe, a study comparing nevirapine extended release with nevirapine immediate release in antiretroviral treatment–naïve patients, and TRANxITION, a study carried out in antiretroviral treatment–experienced patients who switched therapy from nevirapine immediate release to nevirapine extended release, provided data on the noninferiority of the new formulation of nevirapine compared with nevirapine immediate release in terms of efficacy and safety. Nevirapine extended release will further increase the durability and persistence of nevirapine-containing antiretroviral therapy, allowing once-daily dosing regimens.Keywords: nevirapine

  2. Nevirapine modulation of paraoxonase-1 in the liver: An in vitro three-model approach.

    Science.gov (United States)

    Marinho, Aline T; Dias, Clara G; Pinheiro, Pedro F; Lemos, Ana Rita; Antunes, Alexandra M M; Marques, M Matilde; Monteiro, Emília C; Miranda, Joana P; Pereira, Sofia A

    2016-01-20

    Nevirapine is associated with severe hepatotoxicity, through the formation of reactive metabolites. Paraoxonase-1 (PON-1) is a promiscuous enzyme involved in the metabolism of xeno- and endobiotics and proposed as a biomarker of hepatotoxicity. The aim of this work was to explore the effects of nevirapine and its phase I metabolites, 2-hydroxy-nevirapine and 12-hydroxy-nevirapine, on PON-1 activities. 2D and 3D primary cultures of rat hepatocytes, and also HepG2 2D cell cultures, were exposed to nevirapine, 2-hydroxy-nevirapine, and 12-hydroxy-nevirapine. The paraoxonase (POase), arylesterase (AREase) and lactonase (LACase) activities of PON-1 were quantified. Effects of nevirapine and its metabolites were only observed in the 3D cell model. Both nevirapine and 12-hydroxy-nevirapine increased POase (p<0.05, p<0.01) and LACase activities (p<0.05, p<0.001). The AREase activity was increased only upon 12-hydroxy-nevirapine exposure (p<0.01). These modulatory effects were observed at 300μM concentrations of nevirapine and 12-hydroxy-nevirapine. The formation of 12-hydroxy-nevirapine seems to be the main factor responsible for the increase of PON-1 activities induced by nevirapine exposure. This effect was only observed in the 3D model, suggesting that an in vivo-like system is necessary for this modulation to occur. The present data suggest that the 3D model is a more suitable in vitro model than the conventional ones to explore drug effects on PON-1. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Advanced photovoltaic-trough development

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, R.; Yasuda, K.; Merson, B.

    1982-04-01

    The scope of the work on photvoltaic troughs includes analytical studies, hardware development, and component testing. Various aspects of the system have been optimized and improvements have been realized, particularly in the receiver and reflecting surface designs. An empirical system performance model has been developed that closely agrees with measured system performance. This in-depth study of single-axis reflecting linear focus photovoltaic concentrators will be very beneficial in the development of improved models for similar systems as well as other phtovoltaic concentrator designs.

  4. [Anatomical studying of the tear trough area].

    Science.gov (United States)

    Yang, Ningze; Qiu, Wei; Wang, Zhijun; Su, Xiaowei; Jia, Huafeng; Shi, Heng

    2014-01-01

    To explore the mechanism of the aging deformity of tear trough through the anatomic study of the tear trough region. 13 adult cadaveric heads (26 sides), including 9 male heads (18 sides) and 4 female heads (8 sides), aged 22-78 years old, were used. Anatomic study was performed around the orbital, especially tear trough region, with microsurgery instrument under microscope( x 10 times). The lower orbicularis retaining ligament was dissected and exposed. The anatomic location was recorded and photographed. (1) The anatomic layers of the tear trough region contains skin, subcutaneous tissue, orbicularis oculi muscle, periosteal membrane. There is no subcutaneous fat above the tear trough, while it exists below the tear trough, called malar fat pad. (2) There is a natural boundary between the septal and the orbital portions of the orbicularis oculi muscle of lower eyelid at surface of the orbital bone. The natural boundary, projected on the body surface corresponds to tear trough. The width of boundary is (2.06 +/- 0.15) mm on the vertical line through inner canthus and (3.25 +/- 0.12) mm on the vertical line through the lateral margin of the ala. The septal portion and the orbital portion of the orbicularis oculi muscle began to merge in (16.56 +/- 0.51) mm to inner canthus. (3) There is ligament attachment in the medial, upper and lower orbital and no ligament attachment in the lateral orbital. Orbicularis retaining ligament of lower eyelid is divided into two layers. (4) The medial of the upper layer of the orbicularis retaining ligament in lower eyelid originates from orbital margin and from preorbital walls laterally in (16.10 +/- 0.43) mm to the medial of lateral orbital margin, through orbicularis oculi muscle and ends at the skin. The lower layer of the orbicularis retaining ligament of lower eyelid originates from preorbital walls through orbicularis oculi muscle and its superficial fat, then ends at the skin. The length of tear trough is (16.56 +/- 0.51) mm

  5. Lipid-based nutrient supplements do not affect efavirenz but lower plasma nevirapine concentrations in Ethiopian adult HIV patients

    DEFF Research Database (Denmark)

    Abdissa, A; Olsen, Mette Frahm; Yilma, D

    2015-01-01

    OBJECTIVES: Lipid-based nutrient supplements (LNSs) are increasingly used in HIV programmes in resource-limited settings. However, the possible effects of LNSs on the plasma concentrations of antiretroviral drugs have not been assessed. Here, we aimed to assess the effects of LNSs on plasma...... efavirenz and nevirapine trough concentrations in Ethiopian adult HIV-infected patients. METHODS: The effects of LNSs were studied in adults initiating antiretroviral therapy (ART) in a randomized trial. Patients with body mass index (BMI) > 17 kg/m(2) (n = 282) received daily supplementation of an LNS.......9; -0.9 μg/mL; P = 0.01), respectively, compared with the group not receiving supplements. There were no differences between groups with respect to efavirenz plasma concentrations. The CYP2B6 516 G>T polymorphism was associated with a 5 μg/mL higher plasma efavirenz concentration compared with the wild...

  6. Nevirapine plasma concentrations in premature infants exposed to ...

    African Journals Online (AJOL)

    -dose nevirapine (sd NVP) for prevention of mother-to-child transmission (MTCT) of HIV. Aim. To describe NVP decay pharmacokinetics in two groups of premature infants – those whose mothers either received or did not receive NVP during ...

  7. Malaria therapy in HIV: drug interactions between nevirapine and quinine.

    Science.gov (United States)

    Uriel, A; Lewthwaite, P

    2011-12-01

    We report the case of an HIV-positive Nigerian man on antiretroviral therapy (ART) with an undetectable viral load who presented with rigors, fever and back pain after returning to the UK from a three-week trip to Nigeria. Infection with Plasmodium falciparum malaria was confirmed and treatment with quinine commenced together with amoxicillin/clavulanic acid and clarithromycin for possible respiratory infection. At the time of admission the patient could not remember the names of his ART medications. After 24 hours his parasitaemia had increased from 1% to 2.5% and his clinical condition had deteriorated. At this point, his ART was identified as abacavir, lamivudine and nevirapine. The Liverpool HIV-drug interactions website was checked for drug interactions. It recommends caution in the co-administration of both clarithromycin and quinine with nevirapine. Quinine is metabolized by CYP34A and exposure is likely to be decreased by induction of these enzymes in patients taking nevirapine. Given the clinical deterioration the patient was switched to Malarone® (atovoquone/ proguanil) which has no clinically significant interactions with nevirapine. He responded to treatment and was discharged home after 48 hours. This case highlights the importance of knowing the potential drug interactions with ART and the importance of checking for such interactions when prescribing new medications.

  8. Risk of nevirapine-associated Stevens-Johnson syndrome among ...

    African Journals Online (AJOL)

    Background. Stevens-Johnson syndrome (SJS) is an acute life-threatening condition often elicited by drugs. The government's indecisiveness in deciding to stop the use of nevirapine (NVP) in HIV-infected pregnant women owing to the increase of SJS among this population group in South Africa prompted this investigation ...

  9. The origin and evolution of the Cretaceous Benue Trough (Nigeria)

    Science.gov (United States)

    Benkhelil, J.

    The intracontinental Benue Trough was initiated during the Lower Cretaceous in relation with the Atlantic Ocean opening. The first stage of its evolution started in the Aptian, forming isolated basins with continental sedimentation. In the Albian times, a great delta developed in the Upper Benue Trough, while the first marine transgression coming from the opening Gulf of Guinea occurred in the south and reached the Middle Benue. The widespread Turonian transgression made the Atlantic and Tethys waters communicate through the Sahara, Niger basins and the Benue Trough. The tectonic evolution of the Benue Trough was closely controlled by transcurrent faulting through an axial fault system, developing local compressional and tensional regimes and resulting in basins and basement horsts along releasing and restraining bends of the faults. Two major compressional phases occurred: in the Abakaliki area (southern Benue) during the Santonian; and at the end of the Cretaceous in the Upper Benue Trough. In Abakaliki, the sedimentary infilling was severely deformed through folding and flattening, and moderate folding and fracturing occurred in the northeast. The Cretaceous magmatism was restricted to main fault zones in most of the trough but was particularly active in the Abakaliki Trough, where it has alkaline affinities. From Albian to Santonian, the magmatism was accompanied in part of the Abakaliki Trough by a low-grade metamorphism. Geophysical data indicate a crustal thinning beneath the Benue Trough and, at a superficial level, an axial basement high flanked by two elongated deep basins including isolated sub-basins. The model of the tectonic evolution of the trough is based upon a general sinistral wrenching along the trough responsible for the structural arrangement and the geometry of the sub-basins. During the early stages of the Gulf of Guinea opening the Benue Trough was probably the expression on land of the Equatorial Fracture Zones.

  10. Intrapartum single-dose carbamazepine reduces nevirapine levels faster and may decrease resistance after a single dose of nevirapine for perinatal HIV prevention.

    NARCIS (Netherlands)

    Muro, E.P.; Fillekes, Q.; Kisanga, E.R.; L'homme, R.F.A.; Aitken, S.C.; Mariki, G.; Ven, A.J.A.M. van der; Dolmans, W.M.V.; Schuurman, R.; Walker, A.S.; Gibb, D.M.; Burger, D.M.

    2012-01-01

    BACKGROUND: World Health Organization guidelines recommend zidovudine + lamivudine for 7 days from labor onset in HIV-infected women receiving single-dose nevirapine (sdNVP) to cover prolonged subtherapeutic nevirapine concentrations. Although effective, this is complicated and does not eliminate

  11. Slower clearance of nevirapine resistant virus in infants failing extended nevirapine prophylaxis for prevention of mother-to-child HIV transmission.

    Science.gov (United States)

    Persaud, Deborah; Bedri, Abubaker; Ziemniak, Carrie; Moorthy, Anitha; Gudetta, Berhanu; Abashawl, Aida; Mengistu, Yohannes; Omer, Saad B; Isehak, Abdulhamid; Kumbi, Solomon; Adamu, Rahel; Lulseged, Sileshi; Ashworth, Roxann; Hassen, Elham; Ruff, Andrea

    2011-08-01

    Nevirapine resistance mutations arise commonly following single or extended-dose nevirapine (ED-NVP) prophylaxis to prevent mother-to-child transmission (PMTCT) of human immunodeficiency virus (HIV), but decay within 6-12 months of single-dose exposure. Use of ED-NVP prophylaxis in infants is expected to rise, but data on decay of nevirapine resistance mutations in infants in whom ED-NVP failed remain limited. We assessed, in Ethiopian infants participating in the Six-Week Extended Nevirapine (SWEN) Trial, the prevalence and persistence of nevirapine resistance mutations at 6 and 12 months following single-dose or up to 6 weeks of ED-NVP, and correlated their presence with the timing of infection and the type of resistance mutations. Standard population genotyping followed by high-throughput cloning were done on dried blood spot samples collected during the trial. More infants who received ED-NVP had nevirapine resistance detected by standard population genotyping (high frequencies) at age 6 months compared with those who received single-dose nevirapine (SD-NVP) (58% of 24 vs. 26% of 19, respectively; p = 0.06). Moreover, 56% of ED-NVP-exposed infants with nevirapine resistance at age 6 months still had nevirapine resistance mutations present at high frequencies at age 1 year. Infants infected before 6 weeks of age who received either SD- or ED-NVP were more likely to have Y181C or K103N; these mutations were also more likely to persist at high frequencies through 1 year of age. HIV-infected infants in whom ED-NVP prophylaxis fails are likely to experience delayed clearance of nevirapine-resistant virus in the first year of life, which in turn places them at risk for early selection of multidrug-resistant HIV after initial therapy with nonnucleoside reverse transcriptase inhibitor-based regimens.

  12. Oral lesions associated with nevirapine-related Stevens Johnson syndrome: A report of four cases.

    Science.gov (United States)

    Balasundaram, S; Ranganathan, K; Umadevi, K; Gunaseelan, R; Kumaraswamy, N; Solomon, Sunithi; Devaleenol, Bella; Ambrose, Pradeep

    2011-01-01

    Nevirapine is a non-nucleoside reverse transcriptase inhibitor, widely used in combination with other antiretroviral agents for treatment of HIV infection. Steven Johnson syndrome (SJS) is the major toxicity of nevirapine. We describe here four cases of SJS in HIV seropositive patients following nevirapine therapy. In all four cases cutaneous hypersensitivity reaction was seen with extreme oral lesions, three patients presented clinically with elevated liver enzymes and hepatitis, and two patients had ocular involvement.

  13. Investigating the continuous synthesis of a nicotinonitrile precursor to nevirapine

    Directory of Open Access Journals (Sweden)

    Ashley R. Longstreet

    2013-11-01

    Full Text Available 2-Chloro-3-amino-4-picoline (CAPIC is a strategic building block for the preparation of nevirapine, a widely-prescribed non-nucleosidic reverse transcriptase inhibitor for the treatment of HIV-infected patients. A continuous synthesis to the bromo derivative of a CAPIC intermediate, 2-bromo-4-methylnicotinonitrile, that terminates in a dead-end crystallization is described. The route uses inexpensive, acyclic commodity-based raw materials and has the potential to enable lower cost production of nevirapine as well as other value added structures that contain complex pyridines. The route terminates in a batch crystallization yielding high purity CAPIC. This outcome is expected to facilitate regulatory implementation of the overall process.

  14. Spectroscopic and molecular docking studies on the interaction of antiviral drug nevirapine with calf thymus DNA.

    Science.gov (United States)

    Moghadam, Neda Hosseinpour; Salehzadeh, Sadegh; Shahabadi, Nahid

    2017-09-02

    The interaction of calf thymus DNA with nevirapine at physiological pH was studied by using absorption, circular dichroism, viscosity, differential pulse voltammetry, fluorescence techniques, salt effect studies and computational methods. The drug binds to ct-DNA in a groove binding mode, as shown by slight variation in the viscosity of ct-DNA. Furthermore, competitive fluorimetric studies with Hoechst 33258 indicate that nevirapine binds to DNA via groove binding. Moreover, the structure of nevirapine was optimized by DFT calculations and was used for the molecular docking calculations. The molecular docking results suggested that nevirapine prefers to bind on the minor groove of ct-DNA.

  15. Identification of Nevirapine-Resistant HIV-1 in the Latent Reservoir after Single-Dose Nevirapine to Prevent Mother-to-Child Transmission of HIV-1

    Science.gov (United States)

    Wind-Rotolo, Megan; Durand, Christine; Cranmer, Lisa; Reid, Alison; Martinson, Neil; Doherty, Meg; Jilek, Benjamin L.; Kagaayi, Joseph; Kizza, Allan; Pillay, Visva; Laeyendecker, Oliver; Reynolds, Steven J.; Eshleman, Susan H.; Lau, Bryan; Ray, Stuart C.; Siliciano, Janet D.; Quinn, Thomas C.; Siliciano, Robert F.

    2009-01-01

    Background Intrapartum single-dose nevirapine decreases mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) but promotes nevirapine resistance. Although resistant viruses fade to undetectable levels in plasma, they may persist as stably integrated proviruses within the latent reservoir in resting CD4+ T cells, potentially complicating future treatment. Methods Blood samples were collected from 60 women from South Africa and Uganda >6 months after they had received single-dose nevirapine. To selectively analyze the stable latent form of HIV-1, resting CD4+ T cells were isolated and activated in the presence of reverse-transcriptase inhibitors and integrase inhibitors, which allows for the specific isolation of viruses produced by cells with stably integrated proviral DNA. These viruses were then analyzed for nevirapine resistance. Results Although only a small number of latently infected cells were present in each blood sample (mean, 162 cells), nevirapine resistance mutations (K103N and G190A) were detected in the latent reservoir of 4 (8%) of 50 evaluable women. Conclusions A single dose of nevirapine can establish antiretroviral resistance within the latent reservoir. This results in a potentially lifelong risk of reemergence of nevirapine-resistant virus and highlights the need for strategies to prevent transmission that do not compromise successful future treatment. PMID:19338474

  16. Inflammation Is Associated with Voriconazole Trough Concentrations

    Science.gov (United States)

    van Wanrooy, Marjolijn J. P.; Span, Lambert F. R.; Rodgers, Michael G. G.; van den Heuvel, Edwin R.; Uges, Donald R. A.; van der Werf, Tjip S.; Kosterink, Jos G. W.

    2014-01-01

    Voriconazole concentrations display a large variability, which cannot completely be explained by known factors. Inflammation may be a contributing factor, as inflammatory stimuli can change the activities and expression levels of cytochrome P450 isoenzymes. We explored the correlation between inflammation, reflected by C-reactive protein (CRP) concentrations, and voriconazole trough concentrations. A retrospective chart review of patients with at least one steady-state voriconazole trough concentration and a CRP concentration measured on the same day was performed. A total of 128 patients were included. A significantly (P voriconazole trough concentration was observed in patients with severe inflammation (6.2 mg/liter; interquartile range [IQR], 3.4 to 8.7 mg/liter; n = 20) than in patients with moderate inflammation (3.4 mg/liter; IQR, 1.6 to 5.4 mg/liter; n = 60) and in patients with no to mild inflammation (1.6 mg/liter; IQR, 0.8 to 3.0 mg/liter; n = 48). The patients in all three groups received similar voriconazole doses based on mg/kg body weight (P = 0.368). Linear regression analyses, both unadjusted and adjusted for covariates of gender, age, dose, route of administration, liver enzymes, and interacting coadministered medications, showed a significant association between voriconazole and CRP concentration (P voriconazole trough concentration increased by 0.015 mg/liter (unadjusted 95% confidence interval [CI], 0.011 to 0.020 mg/liter; adjusted 95% CI, 0.011 to 0.019 mg/liter). Inflammation, reflected by the C-reactive protein concentration, is associated with voriconazole trough concentrations. Further research is necessary to assess if taking the inflammatory status of a patient into account is helpful in therapeutic drug monitoring of voriconazole to maintain concentrations in the therapeutic window, thereby possibly preventing suboptimal treatment or adverse events. PMID:25223994

  17. Good performance of an immunoassay based method for nevirapine measurements in human breast milk

    DEFF Research Database (Denmark)

    Salado-Rasmussen, Kirsten; Persson Theilgaard, Zahra; Chiduo, Mercy

    2011-01-01

    Understanding the distribution of antiretro-virals in breastfeeding HIV-positive mothers is essential, both for prevention of mother-to-child HIV transmission and for research on the development of drug resistance. The ARK nevirapine (NVP)-test is an immunoassay method for nevirapine measurements...

  18. Maternal deaths following nevirapine-based antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    E Bera

    2012-10-01

    Full Text Available We report 2 cases illustrating that it is too simplistic to link nevirapine (NVP toxicity exclusively to individuals with immune preservation. Not enough is known about the mechanism of hepatotoxicity or cutaneous eruption to predict these events. This type of hypersensitivity reaction occurs rarely among HIV-exposed infants taking NVP prophylaxis or antiretroviral therapy (ART-experienced adults with complete plasma viral load suppression. Conversely, HIV-uninfected adults and ART-naive pregnant women appear to be disproportionately affected by the adverse effects of NVP.

  19. Technical Manual for the SAM Physical Trough Model

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M. J.; Gilman, P.

    2011-06-01

    NREL, in conjunction with Sandia National Lab and the U.S Department of Energy, developed the System Advisor Model (SAM) analysis tool for renewable energy system performance and economic analysis. This paper documents the technical background and engineering formulation for one of SAM's two parabolic trough system models in SAM. The Physical Trough model calculates performance relationships based on physical first principles where possible, allowing the modeler to predict electricity production for a wider range of component geometries than is possible in the Empirical Trough model. This document describes the major parabolic trough plant subsystems in detail including the solar field, power block, thermal storage, piping, auxiliary heating, and control systems. This model makes use of both existing subsystem performance modeling approaches, and new approaches developed specifically for SAM.

  20. Compatibility studies of nevirapine in physical mixtures with excipients for oral HAART

    International Nuclear Information System (INIS)

    Oliveira, G.G.G. de; Ferraz, H.G.; Severino, P.; Souto, E.B.

    2013-01-01

    Nevirapine is a hydrophobic non-nucleoside reverse transcriptase inhibitor, used in first line regimens of highly active antiretroviral therapy (HAART). The drug has more than one crystalline form, which may have implications for its behaviour during production and also for its in vivo performance. This study was aimed at exploring the suitability of thermoanalytical methods for the solid-state characterization of commercial crystalline forms of nevirapine. The drug powder was characterized by ultraviolet spectrophotometry, stereoscopy, scanning electron microscopy, wide-angle X-ray diffraction, measurements of density, flowability, solubility and intrinsic dissolution rate (IDR), differential scanning calorimetry, thermogravimetric analysis, and photostability measurements. The results showed that nevirapine has high stability and is not susceptible to degradation under light exposure. The drug showed compatibility with the excipients tested (lactose, microcrystalline cellulose, polyvinylpyrrolidone and polyvinyl acetate copolymer (PVP/PVA), and hydroxypropylmethylcellulose (HPMC)). Nevirapine has low solubility, an acid medium being the most appropriate medium for assessing the release of the drug from dosage forms. However, the data obtained from IDR testing indicate that dissolution is the critical factor for the bioavailability of this drug. - Graphical abstract: Bulk nevirapine powder analysed by scanning electron microscopy and the drug solubility profile in various buffer solutions. The pH values of the media in which the tests were conducted are also presented. Highlights: ► Nevirapine shows more than one crystalline form, that influence its in vivo and in vitro behaviour. ► DSC and TGA were used for solid-state characterization of crystalline forms of nevirapine. ► Nevirapine is compatible with lactose, microcrystalline cellulose, PVP/PVA copolymers and HPMC. ► The acid form of nevirapine is the most appropriate for assessing release profile from

  1. Compatibility studies of nevirapine in physical mixtures with excipients for oral HAART

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, G.G.G. de; Ferraz, H.G. [Department of Pharmacy, Faculty of Pharmaceutical Health, University of Sao Paulo, Sao Paulo 05508-900 (Brazil); Severino, P. [Department of Biotechnological Processes, School of Chemical Engineering, University of Campinas, Campinas 13083-970 (Brazil); Department of Pharmaceutical Technology, Faculty of Health Sciences, Fernando Pessoa University, Porto 4200-150 (Portugal); Souto, E.B., E-mail: eliana@ufp.edu.pt [Department of Pharmaceutical Technology, Faculty of Health Sciences, Fernando Pessoa University, Porto 4200-150 (Portugal); Institute for Biotechnology and Bioengineering, Centre for Genomics and Biotechnology, University of Tras-os-Montes e Alto Douro (IBB-CGB/UTAD), 5001-801 Vila Real (Portugal)

    2013-03-01

    Nevirapine is a hydrophobic non-nucleoside reverse transcriptase inhibitor, used in first line regimens of highly active antiretroviral therapy (HAART). The drug has more than one crystalline form, which may have implications for its behaviour during production and also for its in vivo performance. This study was aimed at exploring the suitability of thermoanalytical methods for the solid-state characterization of commercial crystalline forms of nevirapine. The drug powder was characterized by ultraviolet spectrophotometry, stereoscopy, scanning electron microscopy, wide-angle X-ray diffraction, measurements of density, flowability, solubility and intrinsic dissolution rate (IDR), differential scanning calorimetry, thermogravimetric analysis, and photostability measurements. The results showed that nevirapine has high stability and is not susceptible to degradation under light exposure. The drug showed compatibility with the excipients tested (lactose, microcrystalline cellulose, polyvinylpyrrolidone and polyvinyl acetate copolymer (PVP/PVA), and hydroxypropylmethylcellulose (HPMC)). Nevirapine has low solubility, an acid medium being the most appropriate medium for assessing the release of the drug from dosage forms. However, the data obtained from IDR testing indicate that dissolution is the critical factor for the bioavailability of this drug. - Graphical abstract: Bulk nevirapine powder analysed by scanning electron microscopy and the drug solubility profile in various buffer solutions. The pH values of the media in which the tests were conducted are also presented. Highlights: Black-Right-Pointing-Pointer Nevirapine shows more than one crystalline form, that influence its in vivo and in vitro behaviour. Black-Right-Pointing-Pointer DSC and TGA were used for solid-state characterization of crystalline forms of nevirapine. Black-Right-Pointing-Pointer Nevirapine is compatible with lactose, microcrystalline cellulose, PVP/PVA copolymers and HPMC. Black

  2. Reversible reduction of nevirapine plasma concentrations during rifampicin treatment in patients coinfected with HIV-1 and tuberculosis.

    Science.gov (United States)

    Matteelli, Alberto; Saleri, Nuccia; Villani, Paola; Bonkoungou, Victor; Carvalho, Anna Cristina C; Kouanda, Seni; Sanou, Marie J; Simporé, Jacques; Monno, Laura; Carosi, Giampiero; Regazzi, Mario; Dembele, Mathurin

    2009-09-01

    Nevirapine (NVP) plasma levels are reduced in patients receiving rifampicin (RFM) for tuberculosis (TB) treatment. We determined variations over time of the pharmacokinetic parameters of NVP in patients who receive RFM. HIV-1-infected patients with CD4+ T-lymphocyte count trough was reduced of 19.5% at T1 compared with T3 (3.3 vs. 4.2 microg/mL; P = 0.02) and of 7.1% at T2 compared with T3 (3.9 vs. 4.2 microg/mL; P = 0.17). The proportion of subjects with C trough values

  3. Antioxidant modulation of nevirapine induced hepatotoxicity in rats

    Directory of Open Access Journals (Sweden)

    Awodele Olufunsho

    2015-03-01

    Full Text Available HIV/AIDS related mortality has been dramatically reduced by the advent of antiretroviral therapy (ART. However, ART presents with associated adverse effects. One of such adverse effects is hepatotoxicity observed with nevirapine (NVP containing ART. Since previous studies showed that NVP hepatotoxicity may be due to oxidative stress via generation of oxidative radicals, this study sought to evaluate the protective effects of antioxidants in alleviating NVP induced hepatotoxicity. Rats were divided into 6 groups with 8 animals per group and received doses of the antioxidants jobelyn (10.7 mg/kg/day, vitamin C (8 mg/kg/day, vitamin E (5 mg/kg/day and/or NVP (6 mg/kg/day for 60 days. The animals were sacrificed on day 61 by cervical dislocation, blood samples were collected for biochemical and hematological examination. The liver of the sacrificed animals was weighed and subjected to histopathological examination. There was a statistically significant (p<0.05 elevation in MDA level observed in the NVP group as compared with control. The results further showed non-significant decreases in the levels of MDA in the NVP plus antioxidant groups, except vitamin C, when compared with the NVP alone group. Vitamin E and Vitamin E plus C treated groups showed significantly (p<0.05 higher levels of SOD, CAT and GSH. The results also showed statistically significantly (p<0.05 lower levels of ALT and AST in the antioxidant treated groups There was an observed significantly (p<0.05 higher level of TP and urea in the antioxidant treated rats. A significantly (p<0.05 higher white blood cell count was observed in the antioxidant groups. Histopathological assessment of the liver extracted from the rats showed no visible pathology across the groups. Observations from this study suggest a potentially positive modulatory effect of antioxidants and may be indicative for the inclusion of antioxidants in nevirapine containing ART.

  4. Extended prophylaxis with nevirapine and cotrimoxazole among HIV-exposed uninfected infants is well tolerated.

    Science.gov (United States)

    Aizire, Jim; Fowler, Mary Glenn; Wang, Jing; Shetty, Avinash K; Stranix-Chibanda, Lynda; Kamateeka, Moreen; Brown, Elizabeth R; Bolton, Steve G; Musoke, Philippa M; Coovadia, Hoosen

    2012-01-28

    Nevirapine and cotrimoxazole are associated with hematologic toxicities and skin-rash. Safety of their concurrent use for prophylaxis over extended periods among HIV-exposed uninfected infants has not been previously assessed. Secondary data analysis of the 'HIV Prevention Trials Network-046 protocol' (version 2.0), a phase-III, randomized, placebo-controlled trial that assessed efficacy and safety of nevirapine prophylaxis against breast milk transmission of HIV-1. Trial infants received 6-month study nevirapine/placebo, and standard-of-care peripartum single-dose nevirapine+/- zidovudine 'tail', and cotrimoxazole prophylaxis from 6 weeks through breastfeeding cessation. Adverse events were monitored using United States Division of AIDS Toxicity Tables (2004). Risk of neutropenia, anemia and skin-rash in the cotrimoxazole + nevirapine and the cotrimoxazole + placebo groups were compared using negative-binomial regression. Incidence of neutropenia and/or anemia, and skin-rash was highest during the first 6 weeks of life and declined, thereafter, regardless of study group. Time to first adverse event after 6 weeks was similar in cotrimoxazole + nevirapine and cotrimoxazole + placebo groups: hazard ratio (95% confidence interval) was 1.26 (0.96-1.66) for neutropenia and/or anemia (all grades), 1.27 (0.80-2.03) for neutropenia and/or anemia (grade ≥3) and 1.16 (0.46-2.90) for skin-rash (grade ≥2). There were no statistically significant differences in immediate (6 weeks-6 months) and long-term (6-12 months) adverse event risk among infants on cotrimoxazole + nevirapine versus cotrimoxazole + placebo. Extended nevirapine and cotrimoxazole prophylaxis through 6 months of age among HIV-exposed uninfected infants did not appear to increase the immediate or long-term risk of neutropenia, anemia or skin-rash. Concurrent use beyond 6 months, however, needs to be evaluated.

  5. Magnetosphere-Ionosphere Coupling Processes in the Ionospheric Trough Region During Substorms

    Science.gov (United States)

    Zou, S.; Moldwin, M.; Nicolls, M. J.; Ridley, A. J.; Coster, A. J.; Yizengaw, E.; Lyons, L. R.; Donovan, E.

    2013-12-01

    The ionospheric troughs are regions of remarkable electron density depression at the subauroral and auroral latitudes, and are categorized into the mid-latitude trough or high-latitude trough, depending on their relative location to the auroral oval. Substorms are one fundamental element of geomagnetic activity, during which structured field-aligned currents (FACs) and convection flows develop in the subauroral and auroral ionosphere. The auroral/trough region is expected to experience severe electron density variations during substorms. Accurate specification of the trough dynamics during substorms and understanding its relationship with the structured FACs and convection flows are of important practical purpose, including providing observational foundations for assessing the attendant impact on navigation and communication. In addition, troughs are important since they map to magnetospheric boundaries allowing the remote sensing of magnetosphere-ionosphere coupling processes. In this talk, we discuss the dynamics of the mid-latitude and high-latitude troughs during substorms based on multi-instrument observations. Using GPS total electron content (TEC) data, we characterize the location and width of the mid-latitude trough through the substorm lifecycle and compare them with existing trough empirical models. Using a combination of incoherent scattering radar (ISR), GPS TEC, auroral imager and a data assimilative model, we investigate the relationship between the high-latitude trough and FACs as well as convection flows. The high-latitude trough is found to be collocated with a counter-clockwise convection flow vortex east of the Harang reversal region, and downward FACs as part of the substorm current system are suggested to be responsible for the high-latitude trough formation. In addition, complex ionospheric electron temperature within the high-latitude trough is found, i.e., increase in the E region while decrease in the F region. We discuss possible

  6. Improvement Design of Parabolic Trough

    Science.gov (United States)

    Ihsan, S. I.; Safian, M. A. I. M.; Taufek, M. A. M.; Mohiuddin, A. K. M.

    2017-03-01

    The performance of parabolic trough solar collector (PTSC) has been evaluated using different heat transfer working fluids; namely water and SAE20 W50 engine oil. New and slightly improved PTSC was developed to run the experimental study. Under the meteorological conditions of Malaysia, authors found that PTSC can operate at a higher temperature than water collector but the performance efficiency of collector using engine oil is much lower than the water collector.

  7. The impact of a Wastewater Treatment Works in Southern Gauteng, South Africa on efavirenz and nevirapine discharges into the aquatic environment

    Directory of Open Access Journals (Sweden)

    C. Schoeman

    2017-06-01

    Although an order of magnitude lower nevirapine concentrations displayed the opposite behaviour and gradually increased through the various stages of purification in the WWTP. Minor fluctuations occurred but the concentrations of nevirapine were higher at the effluent (between 92 and 473 ng/L than those entering the WWTP. No nevirapine was detected in the PST sludge. The increase in nevirapine concentrations are likely to be the result of the de-conjugation of the hydroxylated metabolites of nevirapine in the WWTP, its resistance to degradation and the lack of binding of the nevirapine to the PST sludge.

  8. Pooled individual data analysis of 5 randomized trials of infant nevirapine prophylaxis to prevent breast-milk HIV-1 transmission.

    Science.gov (United States)

    Hudgens, Michael G; Taha, Taha E; Omer, Saad B; Jamieson, Denise J; Lee, Hana; Mofenson, Lynne M; Chasela, Charles; Kourtis, Athena P; Kumwenda, Newton; Ruff, Andrea; Bedri, Abubaker; Jackson, J Brooks; Musoke, Philippa; Bollinger, Robert C; Gupte, Nikhil; Thigpen, Michael C; Taylor, Allan; van der Horst, Charles

    2013-01-01

    In resource-limited settings, mothers infected with human immunodeficiency virus type 1 (HIV-1) face a difficult choice: breastfeed their infants but risk transmitting HIV-1 or not breastfeed their infants and risk the infants dying of other infectious diseases or malnutrition. Recent results from observational studies and randomized clinical trials indicate daily administration of nevirapine to the infant can prevent breast-milk HIV-1 transmission. Data from 5396 mother-infant pairs who participated in 5 randomized trials where the infant was HIV-1 negative at birth were pooled to estimate the efficacy of infant nevirapine prophylaxis to prevent breast-milk HIV-1 transmission. Four daily regimens were compared: nevirapine for 6 weeks, 14 weeks, or 28 weeks, or nevirapine plus zidovudine for 14 weeks. The estimated 28-week risk of HIV-1 transmission was 5.8% (95% confidence interval [CI], 4.3%-7.9%) for the 6-week nevirapine regimen, 3.7% (95% CI, 2.5%-5.4%) for the 14-week nevirapine regimen, 4.8% (95% CI, 3.5%-6.7%) for the 14-week nevirapine plus zidovudine regimen, and 1.8% (95% CI, 1.0%-3.1%) for the 28-week nevirapine regimen (log-rank test for trend, P < .001). Cox regression models with nevirapine as a time-varying covariate, stratified by trial site and adjusted for maternal CD4 cell count and infant birth weight, indicated that nevirapine reduces the rate of HIV-1 infection by 71% (95% CI, 58%-80%; P < .001) and reduces the rate of HIV infection or death by 58% (95% CI, 45%-69%; P < .001). Extended prophylaxis with nevirapine or with nevirapine and zidovudine significantly reduces postnatal HIV-1 infection. Longer duration of prophylaxis results in a greater reduction in the risk of infection.

  9. Inhibition of cytochrome P450 3A enzyme by Millettia aboensis: its effect on the pharmacokinetic properties of efavirenz and nevirapine

    Directory of Open Access Journals (Sweden)

    Sunday O. Nduka

    Full Text Available ABSTRACT The chronic and comorbid nature of HIV infection necessitate the use of multiple drugs including herbs to relieve symptoms with a possible increase in herb–drug interaction cases. This study was designed to evaluate the effect of Millettia aboensis (Hook. f. Baker, Fabaceae, on cytochrome P450 3A isoenzyme and the influence of this effect on the bioavailability of two antiretroviral agents. In vitro effect of ethanol extract of M. aboensis on intestinal and liver microsomes extracted from female rats was assessed using erythromycin-N-demethylation assay method while in vivo effects were determined by estimating simvastatin plasma concentrations in rats. The effect of the extract on pharmacokinetic parameters of orally administered efavirenz (25 mg/kg and nevirapine (20 mg/kg was determined in rats divided into groups (n = 5. Plasma drug concentrations were assayed using HPLC and pharmacokinetic parameters determined through a non-compartmental analysis as implemented in WinNonlin pharmacokinetic program. The extract inhibited both intestinal and liver microsomal cytochrome P450 3A isoenzyme activities in vitro and enhanced simvastatin absorption in vivo with possible inhibition of metabolizing enzymes as indicated by significant (p 0.05 changes in the pharmacokinetic parameters of efavirenz and nevirapine. HPLC fingerprinting indicated the presence of quercetin and kaempferol in the extract. These findings revealed M. aboensis as an inhibitor of cytochrome P450 3A enzyme but, with no significant effect on the bioavailability of orally administered nevirapine and efavirenz.

  10. Exposure of Allium cepa Root Cells to Zidovudine or Nevirapine Induces Cytogenotoxic Changes

    Science.gov (United States)

    Onwuamah, Chika K.; Ekama, Sabdat O.; Audu, Rosemary A.; Ezechi, Oliver C.; Poirier, Miriam C.; Odeigah, Peter G C.

    2014-01-01

    Antiretroviral drugs have proved useful in the clinical management of HIV-infected persons, though there are concerns about the effects of exposure to these DNA-reactive drugs. We investigated the potential of the plant model Allium cepa root tip assay to demonstrate the cytogenotoxicity of zidovudine and nevirapine and as a replace-reduce-refine programme amenable to resource–poor research settings. Cells mitotic index were determined in squashed root cells from Allium cepa bulbs exposed to zidovudine or nevirapine for 48 hr. The concentration of zidovudine and nevirapine inhibiting 50% root growth after 96 hr exposure was 65.0 µM and 92.5 µM respectively. Root length of all antiretroviral-exposed roots after 96 hr exposure was significantly shorter than the unexposed roots while additional root growth during a subsequent 48 hr recovery period in the absence of drug was not significantly different. By ANOVA, there was a significant association between percentage of cells in mitosis and zidovudine dose (p = 0.004), but not nevirapine dose (p = 0.68). Chromosomal aberrations such as sticky chromosomes, chromatin bridges, multipolar mitoses and binucleated cells were observed in root cells exposed to zidovudine and nevirapine for 48 hr. The most notable chromosomal aberration was drug-related increases in sticky chromosomes. Overall, the study showed inhibition in root length growth, changes in the mitotic index, and the induction of chromosomal aberrations in Allium bulbs treated for 96 hr or 48 hr with zidovudine and nevirapine. The study reveals generalized cytogenotoxic damage induced by exposure to zidovudine and nevirapine, and further show that the two compounds differ in their effects on mitosis and the types of chromosomal aberrations induced. PMID:24599327

  11. Effect of diurnal variation, CYP2B6 genotype and age on the pharmacokinetics of nevirapine in African children

    NARCIS (Netherlands)

    Bienczak, A.; Cook, A.; Wiesner, L.; Mulenga, V.; Kityo, C.; Kekitiinwa, A.; Walker, A.S.; Owen, A.; Gibb, D.M.; Burger, D.M.; McIlleron, H.; Denti, P.

    2017-01-01

    OBJECTIVES: To characterize the effects of CYP2B6 polymorphisms, diurnal variation and demographic factors on nevirapine pharmacokinetics in African children. METHODS: Non-linear mixed-effects modelling conducted in NONMEM 7.3 described nevirapine plasma concentration-time data from 414 children

  12. Pharmacokinetics of nevirapine in HIV-infected children under 3 years on rifampicin-based antituberculosis treatment.

    NARCIS (Netherlands)

    Oudijk, J.M.; McIlleron, H.; Mulenga, V.; Chintu, C.; Merry, C.; Walker, A.S.; Cook, A.; Gibb, D.M.; Burger, D.M.

    2012-01-01

    OBJECTIVE:: There is an urgent need to optimize cotreatment for children with tuberculosis and HIV infection. We described nevirapine pharmacokinetics in Zambian children aged less than 3 years, cotreated with nevirapine, lamivudine and stavudine in fixed-dose combination (using WHO weight bands)

  13. Inversion tectonics of the benue trough | Mamah | Global Journal of ...

    African Journals Online (AJOL)

    Spreading was, however, arrested by the rotation of the hot spot plumes onto the shoulders of the trough such as unto the Cameroom volcanic line by a sequence of events including crustal thinning and doming, rifting and faulting, grabens and horst formation, volcanism and subsidence, imbricate sedimentation and ...

  14. Extended-dose nevirapine to 6 weeks of age for infants to prevent HIV transmission via breastfeeding in Ethiopia, India, and Uganda: an analysis of three randomised controlled trials.

    Science.gov (United States)

    Bedri, Abubaker; Gudetta, Berhanu; Isehak, Abdulhamid; Kumbi, Solomon; Lulseged, Sileshi; Mengistu, Yohannes; Bhore, Arvind V; Bhosale, Ramesh; Varadhrajan, Venkat; Gupte, Nikhil; Sastry, Jayagowri; Suryavanshi, Nishi; Tripathy, Srikanth; Mmiro, Francis; Mubiru, Michael; Onyango, Carolyne; Taylor, Adrian; Musoke, Philippa; Nakabiito, Clemensia; Abashawl, Aida; Adamu, Rahel; Antelman, Gretchen; Bollinger, Robert C; Bright, Patricia; Chaudhary, Mohammad A; Coberly, Jacqueline; Guay, Laura; Fowler, Mary Glenn; Gupta, Amita; Hassen, Elham; Jackson, J Brooks; Moulton, Lawrence H; Nayak, Uma; Omer, Saad B; Propper, Lidia; Ram, Malathi; Rexroad, Vivian; Ruff, Andrea J; Shankar, Anita; Zwerski, Sheryl

    2008-07-26

    UNICEF/WHO recommends that infants born to HIV-infected mothers who do not have access to acceptable, feasible, affordable, sustainable, and safe replacement feeding should be exclusively breastfed for at least 6 months. The aim of three trials in Ethiopia, India, and Uganda was to assess whether daily nevirapine given to breastfed infants through 6 weeks of age can decrease HIV transmission via breastfeeding. HIV-infected women breastfeeding their infants were eligible for participation. Participants were randomly assigned to receive either single-dose nevirapine (nevirapine 200 mg to women in labour and nevirapine 2 mg/kg to newborns after birth) or 6 week extended-dose nevirapine (nevirapine 200 mg to women in labour and nevirapine 2 mg/kg to newborn babies after birth plus nevirapine 5 mg daily from days 8-42 for the infant). The randomisation sequences were generated by computer at a central data coordinating centre. The primary endpoint was HIV infection at 6 months of age in infants who were HIV PCR negative at birth. Analyses were by modified intention to treat, excluding infants with missing specimens and those with indeterminate or confirmed HIV infection at birth. These studies are registered with ClinicalTrials.gov, numbers NCT00074399, NCT00061321, and NCT00639938. 2024 liveborn infants randomised in the study had at least one specimen tested before 6 months of age (1047 infants in the single-dose group and 977 infants in the extended-dose group). The modified intention-to-treat population included 986 infants in the single-dose group and 901 in the extended-dose group. At 6 months, 87 children in the single-dose group and 62 in the extended-dose group were infected with HIV (relative risk 0.80, 95% CI 0.58-1.10; p=0.16). At 6 weeks of age, 54 children in the single-dose group and 25 in the extended-dose group were HIV positive (0.54, 0.34-0.85; p=0.009). 393 infants in the single-dose group and 346 in the extended-dose group experienced grade 3 or 4

  15. The De Long Trough: a newly discovered glacial trough on the East Siberian continental margin

    Directory of Open Access Journals (Sweden)

    M. O'Regan

    2017-09-01

    Full Text Available Ice sheets extending over parts of the East Siberian continental shelf have been proposed for the last glacial period and during the larger Pleistocene glaciations. The sparse data available over this sector of the Arctic Ocean have left the timing, extent and even existence of these ice sheets largely unresolved. Here we present new geophysical mapping and sediment coring data from the East Siberian shelf and slope collected during the 2014 SWERUS-C3 expedition (SWERUS-C3: Swedish – Russian – US Arctic Ocean Investigation of Climate-Cryosphere-Carbon Interactions. The multibeam bathymetry and chirp sub-bottom profiles reveal a set of glacial landforms that include grounding zone formations along the outer continental shelf, seaward of which lies a  >  65 m thick sequence of glacio-genic debris flows. The glacial landforms are interpreted to lie at the seaward end of a glacial trough – the first to be reported on the East Siberian margin, here referred to as the De Long Trough because of its location due north of the De Long Islands. Stratigraphy and dating of sediment cores show that a drape of acoustically laminated sediments covering the glacial deposits is older than ∼ 50 cal kyr BP. This provides direct evidence for extensive glacial activity on the Siberian shelf that predates the Last Glacial Maximum and most likely occurred during the Saalian (Marine Isotope Stage (MIS 6.

  16. Lack of increased hepatotoxicity in HIV-infected pregnant women receiving nevirapine compared with other antiretrovirals.

    Science.gov (United States)

    Ouyang, David W; Brogly, Susan B; Lu, Ming; Shapiro, David E; Hershow, Ronald C; French, Audrey L; Leighty, Robert M; Thompson, Bruce; Tuomala, Ruth E

    2010-01-02

    To estimate whether HIV-infected pregnant women were at an increased risk of hepatotoxicity when taking nevirapine (NVP)-containing regimens compared with HIV-infected pregnant women taking antiretroviral therapy (ART) not containing NVP. This analysis included HIV-infected pregnant women on ART from two multicenter, prospective cohorts: the Women and Infants Transmission Study and the International Maternal Pediatric Adolescent AIDS Clinical Trials protocol P1025. Multivariate Cox proportional hazards regression models were used to investigate the association between NVP use and hepatotoxicity. NVP use was dichotomized as use or no use and further categorized according to ART exposure history. We investigated two outcomes: any liver enzyme elevation (LEE) (grade 1-4) and severe LEE (grade 3-4). A total of 1229 women with ART use during pregnancy were studied, 218 (17.7%) of whom received NVP. Among the women receiving NVP, 137 (62.8%) were NVP naive. Twenty-nine women (13.3%) who received NVP developed any LEE and one (0.5%) developed severe LEE. Of the 1011 women on non-NVP regimens, 145 (14.3%) developed any LEE and 14 (1.4%) developed severe LEE. There were no maternal deaths. In univariate models, LEE was not significantly associated with CD4 cell count above 250 cells/mul or NVP use. In adjusted multivariate models, no significant increased risk of LEE (any or severe) in women taking NVP was detected as compared to those taking other ART regardless of prior exposure history. We did not observe an increased risk of hepatotoxicity among HIV-infected pregnant women on NVP versus other ART, including women who were ART naive.

  17. Determinants of virological outcome and adverse events in African children treated with paediatric nevirapine fixed-dose-combination tablets

    NARCIS (Netherlands)

    Bienczak, A.; Denti, P.; Cook, A.; Wiesner, L.; Mulenga, V.; Kityo, C.; Kekitiinwa, A.; Gibb, D.M.; Burger, D.M.; Walker, A.S.; McIlleron, H.

    2017-01-01

    BACKGROUND: Nevirapine is the only nonnucleoside reverse transcriptase inhibitor currently available as a paediatric fixed-dose-combination tablet and is widely used in African children. Nonetheless, the number of investigations into pharmacokinetic determinants of virological suppression in African

  18. Changing incidence of nevirapine-induced cutaneous drug reactions: After revised guideline Nov 2011.

    Science.gov (United States)

    Lokhande, Archana J; Sutaria, Amita; Shah, Bela J; Shah, Asha N

    2013-07-01

    To study the change in the incidence and pattern of nevirapine (NVP)-induced adverse cutaneous reactions (ADR) after commencement of revised National AIDS Control Organisation (NACO) guidelines for initiation of antiretroviral therapy (ART) since Nov 2011. The study was conducted on patients who developed cutaneous reactions after starting NVP based regimen. According to the revised NACO ART initiation guidelines Nov 2011, ART should be started if CD4 count is < 350 cells/mm(3) in stages 1, and 2 and irrespective of CD4 count in stages 3, and 4. Patients were divided in groups A and B. Group A consisted of patients enrolled on NVP-based regimen during Jan 2011 to Oct 2011, whereas, in Group B patients from Nov 2011 to Aug 2012 were included. Grading of rash, appropriate investigations and management was done. In Group A, out of 645 patients 30 (4.66%) patients developed cutaneous reactions, where as in Group B out of 720, 65 (9.03%) patients presented with drug reaction. In Group A (n = 30) developed reaction as Grade 1 in 1.55% (n = 10), Grade 2 in 1.86% (n = 12), grades 3 and 4 in 0.76% (n = 5) and 0.47% (n = 3), respectively. In Group B (n = 65) developed reaction, out of which Grade 1 reaction was seen in 1.39% (n = 10), Grade 2 was seen in 2.78% (n = 20), grades 3 and 4 was seen in 3.33% (n = 24) and, 1.53% (n = 11), respectively. There is a striking increase in the incidence of NVP-induced cutaneous reactions of all forms and considerable increase in frequency of severe kind of reactions with the revised guidelines.

  19. Parabolic Trough Collector Cost Update for the System Advisor Model (SAM)

    Energy Technology Data Exchange (ETDEWEB)

    Kurup, Parthiv [National Renewable Energy Lab. (NREL), Golden, CO (United States); Turchi, Craig S. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-11-01

    This report updates the baseline cost for parabolic trough solar fields in the United States within NREL's System Advisor Model (SAM). SAM, available at no cost at https://sam.nrel.gov/, is a performance and financial model designed to facilitate decision making for people involved in the renewable energy industry. SAM is the primary tool used by NREL and the U.S. Department of Energy (DOE) for estimating the performance and cost of concentrating solar power (CSP) technologies and projects. The study performed a bottom-up build and cost estimate for two state-of-the-art parabolic trough designs -- the SkyTrough and the Ultimate Trough. The SkyTrough analysis estimated the potential installed cost for a solar field of 1500 SCAs as $170/m2 +/- $6/m2. The investigation found that SkyTrough installed costs were sensitive to factors such as raw aluminum alloy cost and production volume. For example, in the case of the SkyTrough, the installed cost would rise to nearly $210/m2 if the aluminum alloy cost was $1.70/lb instead of $1.03/lb. Accordingly, one must be aware of fluctuations in the relevant commodities markets to track system cost over time. The estimated installed cost for the Ultimate Trough was only slightly higher at $178/m2, which includes an assembly facility of $11.6 million amortized over the required production volume. Considering the size and overall cost of a 700 SCA Ultimate Trough solar field, two parallel production lines in a fully covered assembly facility, each with the specific torque box, module and mirror jigs, would be justified for a full CSP plant.

  20. Effect of 7 days of phenytoin on the pharmacokinetics of and the development of resistance to single-dose nevirapine for perinatal HIV prevention: a randomized pilot trial.

    Science.gov (United States)

    Fillekes, Quirine; Muro, Eva P; Chunda, Catherine; Aitken, Susan; Kisanga, Elton R; Kankasa, Chipepo; Thomason, Margaret J; Gibb, Diana M; Walker, A Sarah; Burger, David M

    2013-11-01

    To confirm whether 7 days of phenytoin, an enzyme inducer, would decrease the elimination half-life of single-dose nevirapine and to investigate its effect on the development of nevirapine resistance in pregnant, HIV-infected women. In a pharmacokinetic pilot trial (NCT01187719), HIV-infected, antiretroviral (ARV)-naive pregnant women ≥18 years old from Zambia and Tanzania and with CD4 cell counts >350 cells/mm(3) were randomized 1 : 1 to a control (zidovudine pre-delivery, single-dose nevirapine/zidovudine/lamivudine at delivery and zidovudine/lamivudine for 7 days post-delivery) or an intervention (control plus 184 mg of phenytoin once daily for 7 days post-delivery) group. Primary endpoints were the pharmacokinetics of and resistance to nevirapine. Thirty-five and 37 women were allocated to the control and intervention groups, with median (IQR) ages of 27 (23-31) and 27 (23-33) years, respectively. Twenty-three and 23 women had detectable nevirapine levels at delivery and subsequent samples in the control and the intervention groups, respectively. Geometric mean (GM) (95% CI) plasma levels of nevirapine at delivery were 1.02 (0.58-1.78) mg/L and 1.14 (0.70-1.86) mg/L in the control and intervention groups, respectively (P = 0.76). One week after delivery, 0/23 (0%) and 15/22 (68%) control and intervention mothers, respectively, had undetectable levels of nevirapine ( 0.28). Adding 7 days of an enzyme inducer to single-dose nevirapine to prevent mother-to-child transmission of HIV significantly reduced subtherapeutic nevirapine levels by shortening the half-life of nevirapine. As prolonged subtherapeutic nevirapine dosage leads to the emergence of resistance, single-dose nevirapine could be used with phenytoin as an alternative if other ARVs were unavailable.

  1. A New Validated RP- HPLC Method for the Determination of Nevirapine in Human Plasma

    Directory of Open Access Journals (Sweden)

    C. H. Venkata Kumar

    2010-01-01

    Full Text Available A rapid, selective and sensitive high performance liquid chromatographic method for the estimation of nevirapine in human plasma has been developed. Chromatography was carried out on a Hypersil BDS C18 column using a mixture of ammonium acetate buffer (pH 4.0 ± 0.05 and acetonitrile (85:15 v/v as the mobile phase. The eluents were monitored for the drug by UV detection at 254 nm. Oxcarbazepine was used as an internal standard for this study. The retention times for nevirapine and oxcarbazepine were found to be 7.2 and 14.7 min respectively. The method was found to be linear in the concentration range of 50 ng/mL to 5003.7 ng/mL. The method was validated as per FDA guidelines and was found to be suitable for bioequivalence and pharmacokinetic studies.

  2. Simple, precise and accurate HPLC method of analysis for nevirapine suspension from human plasma.

    Science.gov (United States)

    Halde, S; Mungantiwar, A; Chintamaneni, M

    2011-07-01

    A selective and sensitive high performance liquid chromatography with UV detector (HPLC-UV) method was developed and validated from human plasma. Nevirapine and internal standard (IS) zidovudine were extracted from human plasma by liquid-liquid extraction process using methyl tert-butyl ether. The samples were analysed using Inertsil ODS 3, 250×4.6 mm, 5 μ column using a mobile phase consists of 50 mM sodium acetate buffer solution (pH-4.00±0.05): acetonitrile (73:27 v/v). The method was validated over a concentration range of 50.00 ng/ml to 3998.96 ng/ml. The method was successfully applied to bioequivalence study of 10 ml single dose nevirapine oral suspension 50 mg/5 ml in healthy male volunteers.

  3. Gas Turbine/Solar Parabolic Trough Hybrid Design Using Molten Salt Heat Transfer Fluid: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, C. S.; Ma, Z.

    2011-08-01

    Parabolic trough power plants can provide reliable power by incorporating either thermal energy storage (TES) or backup heat from fossil fuels. This paper describes a gas turbine / parabolic trough hybrid design that combines a solar contribution greater than 50% with gas heat rates that rival those of natural gas combined-cycle plants. Previous work illustrated benefits of integrating gas turbines with conventional oil heat-transfer-fluid (HTF) troughs running at 390?C. This work extends that analysis to examine the integration of gas turbines with salt-HTF troughs running at 450 degrees C and including TES. Using gas turbine waste heat to supplement the TES system provides greater operating flexibility while enhancing the efficiency of gas utilization. The analysis indicates that the hybrid plant design produces solar-derived electricity and gas-derived electricity at lower cost than either system operating alone.

  4. Mid-Oceanic Troughs and Associated Teleconnection Patterns

    Science.gov (United States)

    Lu, Mengmeng; Deng, Kaiqiang; Yang, Song; Zhou, Guojun; Tan, Yaheng

    2017-04-01

    The mid-oceanic troughs (MOTs) are two prominent circulation systems over the North Pacific and the North Atlantic during the boreal summer, which act as the atmospheric bridges linking their adjacent continental climate. On interannual time scale, the variation of the mid-Atlantic trough (MAT) is significantly associated with the NAO variability and a southeastward propagating stationary wave that originates from the northeastern Pacific. The MAT is significantly correlated with the surface climate including the precipitation and surface temperature over the American-Atlantic-Eurasian sector. On interdecadal time scale, the variation of the MAT is strongly related to the AMO and associated with a dipole structure of anomalous precipitation over the North Atlantic and the Greenland. This study also shows that the most dominant mode of the mid-Pacific trough (MPT) is associated with the eastern Pacific La Niña-like pattern and Atlantic SST variability, while the second mode is related to the central Pacific El Niño-like pattern and Arctic sea ice variability. These two modes of the MPT are linked to the Asian-Pacific-American precipitation and surface temperature differently.

  5. HIV infection, viral load, low birth weight, and nevirapine are independent influences on growth velocity in HIV-exposed South African infants.

    Science.gov (United States)

    Ramokolo, Vundli; Lombard, Carl; Fadnes, Lars T; Doherty, Tanya; Jackson, Debra J; Goga, Ameena E; Chhagan, Meera; Van den Broeck, Jan

    2014-01-01

    Data from a prospective multisite cohort study were used to examine the effect of HIV exposure, untreated HIV infection, and single-dose nevirapine on infant growth velocity. The 2009 WHO growth velocity standards constitute a new tool for this type of investigation and are in need of functional validation. In period 1 (3-24 wk), 65 HIV-infected, 502 HIV-exposed uninfected (HEU), and 216 HIV-unexposed infants were included. In period 2 (25-36 wk), 31 infants moved from the HEU group to the HIV-infected group. We compared weight velocity Z-scores (WVZ) and length velocity Z-scores (LVZ) by HIV group and assessed their independent influences. In period 1, mean WVZ (95% CI) was significantly (P infected [-0.87 (-1.77, 0.04)] than HEU [0.81 (0.67, 0.94)] and unexposed [0.55 (0.33, 0.78)] infants. LVZ showed similar associations. In both periods, sick infants and those exposed to higher maternal viral loads had lower WVZ. Higher mean LVZ was associated with low birth weight. Infants that had received nevirapine had higher LVZ. In conclusion, HIV infection and not exposure was associated with low WVZ and LVZ in period 1. Eliminating infant HIV infection is a critical component in averting HIV-related poor growth patterns in infants in the first 6 mo of life.

  6. Nevirapine, sodium concentration and HIV-1 RNA in breast milk and plasma among HIV-infected women receiving short-course antiretroviral prophylaxis

    DEFF Research Database (Denmark)

    Salado-Rasmussen, Kirsten; Theilgaard, Zahra Persson; Chiduo, Mercy G.

    2015-01-01

    Introduction Risk factors for breast milk transmission of HIV-1 from mother to child include high plasma and breast milk viral load, low maternal CD4 count and breast pathology such as mastitis. Objective To determine the impact of nevirapine and subclinical mastitis on HIV-1 RNA in maternal plasma...... and breast milk after intrapartum single-dose nevirapine combined with either 1-week tail of Combivir (zidovudine/lamivudine) or single-dose Truvada (tenofovir/emtricitabine). Methods Maternal plasma and bilateral breast milk samples were collected between April 2008 and April 2011 at 1, 4 and 6 weeks....../mL), respectively. Maternal plasma and breast milk HIV-1 RNA correlated at all visits (R = 0.48, R = 0.7, R = 0.59; all P = 0.01). Subclinical mastitis was detected in 67% of the women at some time during 6 weeks, and in 38% of the breast milk samples. Breast milk samples with subclinical mastitis had significantly...

  7. Aerial mulching techniques-trough fire

    Science.gov (United States)

    Robert. Faust

    2008-01-01

    The Trough fire occurred in August 2001 on the Mendocino National Forest of northern California. A burned area emergency rehabilitation team evaluated the fire effects on the watershed. Concerns were soil from the denuded slopes moving into streams affecting fishery values, reservoir sedimentation and storm runoff plugging culverts leading to road wash outs. Past...

  8. Climatology of the autumn Red Sea trough

    Science.gov (United States)

    Awad, Adel M.; Mashat, Abdul-Wahab S.

    2018-03-01

    In this study, the Sudan low and the associated Red Sea trough (RST) are objectively identified using the mean sea level pressure (SLP) data from the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis dataset covering the period 1955-2015. The Sudan low was detected in approximately 60.6% of the autumn periods, and approximately 83% of the detected low-pressure systems extended into RSTs, with most generated at night and during cold months. The distribution of the RSTs demonstrated that Sudan, South Sudan and Red Sea are the primary development areas of the RSTs, generating 97% of the RSTs in the study period. In addition, the outermost areas affected by RSTs, which include the southern, central and northern Red Sea areas, received approximately 91% of the RSTs originating from the primary generation areas. The synoptic features indicated that a Sudan low developed into an RST when the Sudan low deepened in the atmosphere, while the low pressures over the southern Arabian Peninsula are shallow and the anticyclonic systems are weakened over the northern Red Sea. Moreover, stabile areas over Africa and Arabian Peninsula form a high stability gradient around the Red Sea and the upper maximum winds weaken. The results of the case studies indicate that RSTs extend northward when the upper cyclonic and anticyclonic systems form a high geopotential gradient over Arabian Peninsula. Furthermore, the RST is oriented from the west to the east when the Azores high extends eastward and the Siberian high shrinks eastward or shifts northward.

  9. Electrochemical studies of nevirapine, an anti-HIV drug, and its assay in tablets and biological samples

    Directory of Open Access Journals (Sweden)

    JALDAPPAGARI SEETHARAMAPPA

    2012-06-01

    Full Text Available The electrochemical oxidation of nevirapine, an anti-HIV drug, at a glassy carbon electrode has been studied by voltammetric techniques. Nevirapine showed one well defined irreversible oxidation peak with a potential of 0.749 V in phosphate buffer at pH 10. The effects of different electrolytes, pH and scan rate on the electrochemical behaviour of nevira¬pine were examined to determine the optimum reaction conditions. The oxidation peak current was found to vary linearly with the concentration of nevirapine in the range of 5.0 – 350 µM. The limit of detection and limit of quantification values were calculated and found to be 1.026 µM and 3.420 µM, respectively. The low relative standard deviation values of inter-day and intra-day assays highlighted the good reproducibility of the proposed m¬ethod for assay of nevirapine. Further, a sensitive and accurate differential pulse voltammetric method was developed for the determination of nevirapine concentrations in pharma¬ceutical formulations.

  10. Are Vancomycin Trough Concentrations of 15 to 20 mg/L Associated With Increased Attainment of an AUC/MIC ≥ 400 in Patients With Presumed MRSA Infection?

    Science.gov (United States)

    Hale, Cory M; Seabury, Robert W; Steele, Jeffrey M; Darko, William; Miller, Christopher D

    2017-06-01

    To determine whether there is an association between higher vancomycin trough concentrations and attainment of a calculated area under the concentration-time curve (AUC)/minimum inhibitory concentration (MIC) ≥400. A retrospective analysis was conducted among vancomycin-treated adult patients with a positive methicillin-resistant Staphylococcus aureus (MRSA) culture. Attainment of a calculated AUC/MIC ≥400 was compared between patients with troughs in the reference range of 15 to 20 mg/L and those with troughs in the following ranges: 20 mg/L. Nephrotoxicity was assessed as a secondary outcome based on corrected average vancomycin troughs over 10 days of treatment. Overall, 226 patients were reviewed and 100 included. Relative to troughs ≥10, patients with vancomycin troughs 20 mg/L when compared to patients with troughs of 15 to 20 mg/L. The mean corrected average vancomycin trough was higher in patients developing nephrotoxicity compared to those who did not (19.5 vs 14.5 mg/L, P vancomycin serum trough concentrations of 15 to 20 mg/L did not result in an increased attainment of the AUC/MIC target relative to troughs of 10 to 14.9 mg/L but may increase nephrotoxicity risk.

  11. Intrapartum tenofovir and emtricitabine reduces low-concentration drug resistance selected by single-dose nevirapine for perinatal HIV prevention.

    Science.gov (United States)

    Chi, Benjamin H; Ellis, Giovanina M; Chintu, Namwinga; Cantrell, Ronald A; Sinkala, Moses; Aldrovandi, Grace M; Warrier, Ranjit; Mbewe, Felistas; Nakamura, Kyle; Stringer, Elizabeth M; Frenkel, Lisa M; Stringer, Jeffrey S A

    2009-11-01

    A single dose of tenofovir/emtricitabine (TDF/FTC) during labor significantly reduces peripartum nevirapine-associated viral drug resistance when measured by consensus HIV sequencing. It is unknown whether this effect extends to HIV subpopulations of or = 2% of the viral population, we used an oligonucleotide ligation assay (OLA) at codons 103, 106, 181, and 190 of HIV reverse transcriptase. To assess development of drug resistance mutations to our study intervention, OLA was also performed at codons 65 and 184. Among the 328 women included in the 2-week analysis, those receiving TDF/FTC were less likely to have NNRTI resistance by OLA (RR = 0.40, 95% CI = 0.21-0.77). A similar trend was observed among the 315 women included in the 6-week analysis (RR = 0.45, 95% CI = 0.31-0.66). Only two (1%) specimens had detectable K65R by OLA. Both were at 6 weeks postpartum; one was detected in the intervention arm and one in the control arm (p = 0.96). M184V was not detected. The ability of single-dose TDF/FTC to protect against peripartum NVP-induced NNRTI resistance extends to minority populations. This efficacy is achieved without significant selection of TDF- or FTC-resistant viruses.

  12. Detection of HIV drug resistance mutations in pregnant women receiving single dose Nevirapine in south India

    Directory of Open Access Journals (Sweden)

    Mini S Jacob

    2011-01-01

    Full Text Available Background: Single dose of Nevirapine to prevent mother to child transmission of HIV is the commonest preventive regimen in resource-limited countries. Objectives: The objective of this study was to detect drug-resistant virus after single dose of Nevirapine (sdNVP provided to delivering HIV seropositive (HIV+ve women and to evaluate the time taken for its decay. Results: Of the 36 consenting HIV+ve pregnant women enrolled into the study, the mean hemoglobin and total lymphocyte counts were 10.8 g/dl and 1843 cells/mm 3 , respectively. Mean CD4 counts in 64% of women was 363 cells/mm 3 and mean viral load for 16/36 women was 28,143 copies/ml of plasma. Nevirapine-resistance mutations were detected in 28% of women at delivery; using OLA (Oligonucleotide Ligation Assay. K103N mutations were seen in 19.4% of women while the Y181C mutation was seen in 5%. Both the mutations were detected in 2.7% of women. Sequential blood samples collected at delivery, 7-10 days, 6 weeks, 4 months, 6 months and one year postpartum showed that 81% of K103N mutations and 66.7% of Y181C mutations were detected at 6 weeks postpartum . Wild-type virus had replaced the mutants by one year postpartum in all women except one. Conclusion : These observations are relevant for future treatment with antiretroviral therapy in these women for their HIV disease.

  13. Nevirapine-based antiretroviral therapy does not reduce oral contraceptive effectiveness.

    Science.gov (United States)

    Nanda, Kavita; Delany-Moretlwe, Sinead; Dubé, Karine; Lendvay, Anja; Kwok, Cynthia; Molife, Lebohang; Nakubulwa, Sarah; Edward, Vinodh A; Mpairwe, Bernard; Mirembe, Florence M

    2013-10-01

    To evaluate the effect of nevirapine-containing antiretroviral therapy (ART) on combined oral contraceptive (COC) effectiveness. Nonrandomized prospective clinical trial. We enrolled HIV-infected women aged 18-35 years in South Africa and Uganda who had regular menses, were sexually active, and had no medical contraindications to COC use. We enrolled 196 women taking nevirapine-containing ART and 206 women not yet eligible for ART as a control group. We treated all participants with low-dose COCs. Our main outcomes were ovulation and pregnancy rates. We estimated ovulation in the first two cycles using weekly serum progesterone and tested for pregnancy monthly for 24 weeks. The median age of participants was 29 and their median CD4 cell count was 486. In the ART group, 43 of 168 (26%) ovulated in cycle 1, 30 of 163 (18%) in cycle 2, and 18 of 163 (11%) in both cycles. In the non-ART group, 26 of 168 (16%) ovulated in cycle 1, 31 of 165 (19%) in cycle 2, and 20 of 165 (12%) in both cycles. We found no significant difference in ovulation rates between groups: unadjusted odds ratio 1.36 (95% confidence interval 0.85-2.18). Pregnancy rates also did not differ: 10.0 per 100-women-years in the ART group and 10.1 per 100-women-years in the non-ART group. Self-reported COC adherence, condom use, vaginal bleeding, and adverse events were similar. Five serious adverse events were reported, all in the non-ART group. ART use did not affect risk of ovulation or pregnancy in women taking COCs, suggesting that nevirapine-containing ART does not interfere with COC contraceptive effectiveness.

  14. Analysis of a photovoltaic-electrolyser direct-coupling system with a V-trough concentrator

    International Nuclear Information System (INIS)

    Su, Ziyun; Ding, Shuiting; Gan, Zhiwen; Yang, Xiaoyi

    2016-01-01

    Highlights: • A V-trough concentrator is applied in PVE system. • An analysis model for the CPVE system is established and verified experimentally. • The result shows that the V-trough concentrator increases the system efficiency. • The hydrogen production of the PVE system is doubled in this investigation. - Abstract: Hydrogen is a clean energy carrier for energy storage which is essential to solar system for continuous energy output. A promising method to store solar energy as hydrogen energy is by using photovoltaic-electrolyser (PVE) system. In this investigation, the operation of a PVE system with V-trough concentrator was studied experimentally and numerically. The V-trough concentrator was optimized and the daily average concentration ratio reaches about 1.9. A mathematical model including the sub models for irradiation flux pattern, PV array and electrolyser was established to analyze the characteristics of the system and it was verified experimentally. The results show that the utilization of V-trough concentrator makes PVE system work more efficiently with the same PV array. In this study, the conversion efficiency of solar energy to hydrogen energy was increased from 5.62% to 6.18% and the hydrogen production was doubled.

  15. Crustal structure of the NE Rockall Trough from wide-angle seismic data modeling

    Science.gov (United States)

    KlingelhöFer, F.; Edwards, R. A.; Hobbs, R. W.; England, R. W.

    2005-11-01

    Two wide-angle seismic lines located in the northern Rockall Trough were acquired in May 2000. One line (line E) crosses the trough from the continental shelf off Lewis to normal oceanic crust west of Lousy Bank in NW-SE direction. The other line (line D) intersects with line E, crosses the Wyville-Thomson Ridge in a SW-NE direction and ends in the Faeroe-Shetland Basin. Sonobuoy data and expanding spread profiles acquired in the same area have been remodeled. Analysis of the seismic data using travel times and amplitudes reveals an up to 5 km thick sedimentary basin including an up to 1.5 km thick basaltic layer which is present in most of the trough. Further conclusions of this study are that the Rockall Trough is underlain by highly stretched continental crust of ˜13 km thickness. The crust thickens to ˜24 km beneath Lousy Bank, which is interpreted to be of continental nature. Beneath the Hebrides continental shelf a three-layer continental crust of 26 km is modeled. An up to 12 km thick high-velocity layer is observed underneath the ocean-continent boundary and is interpreted as magmatic underplating resulting from excess volcanism during rifting. No evidence for an underplate layer could be distinguished beneath the trough area. Modeling of the structure of the Wyville-Thomson Ridge revealed no existing igneous core of the ridge confirming existing theories, that it is a compressional structure.

  16. Incidence of nevirapine-associated hepatitis in an antenatal clinic ...

    African Journals Online (AJOL)

    based highly active antiretroviral therapy at a dedicated antenatal antiretroviral clinic between July 2004 and December 2006. Results. Three hundred and ninety women were included in the analysis. Median age was 29 (interquartile range (IQR)

  17. Sex differences in hepatic and intestinal contributions to nevirapine biotransformation in rats.

    Science.gov (United States)

    Pinheiro, P F; Marinho, A T; Antunes, A M M; Marques, M M; Pereira, S A; Miranda, J P

    2015-05-25

    The understanding of the intestine contribution to drug biotransformation improved significantly in recent years. However, the sources of inter-individual variability in intestinal drug biotransformation, namely sex-differences, are still elusive. Nevirapine (NVP) is an orally taken anti-HIV drug associated with severe idiosyncratic reactions elicited by toxic metabolites, with women at increased risk. As such, NVP is a good model to assess sex-dimorphic metabolism. The aim of this study was to perform a comparative profiling of NVP biotransformation in rat intestine and liver and evaluate whether or not it is organ- and sex-dependent. Therefore, nevirapine-containing solutions were perfused through the intestine, in a specially designed chamber, or incubated with liver slices, from male and female Wistar rats. The levels of NVP and its Phase I metabolites were quantified by HPLC-UV. Liver incubation experiments yielded the metabolites 2-, 3-, 8-, and 12-OH-NVP, being 12-OH-NVP and 2-OH-NVP the major metabolites in males and females, respectively. Inter-sex differences in the metabolic profile were also detected in the intestine perfusion experiments. Herein, the metabolites 3- and 12-OH-NVP were only found in male rats, whereas 2-OH-NVP levels were higher in females, both in extraluminal (pbiotransformation was observed, strengthening the relevance of the intestinal contribution in the biotransformation of orally taken-drugs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. Parabolic Trough Solar Collector Initial Trials

    OpenAIRE

    Ghalya Pikra; Agus Salim; Andri Joko Purwanto; Zaidan Eddy

    2012-01-01

    This paper discusses initial trials of parabolic trough solar collector (PTSC) in Bandung. PTSC model consists of concentrator, absorber and tracking system. Concentrator designs are made with 2m aperture width, 6m length and 0.75m focal distance. The design is equipped with an automatic tracking system which is driven using 12V and 24Watt DC motor with 0.0125rpm rotational speed. Absorber/receiver is designed with evacuated tube type, with 1 inch core diameter and tube made of AISI304 and co...

  19. Effect of Moringa oleifera Lam. leaf powder on the pharmacokinetics of nevirapine in HIV-infected adults: a one sequence cross-over study.

    Science.gov (United States)

    Monera-Penduka, Tsitsi G; Maponga, Charles C; Wolfe, Alan R; Wiesner, Lubbe; Morse, Gene D; Nhachi, Charles F B

    2017-01-01

    Moringa oleifera Lam., an herb commonly consumed by HIV-infected people on antiretroviral therapy, inhibits cytochrome P450 3A4, 1A2 and 2D6 activity in vitro; and may alter the pharmacokinetics (PK) of antiretroviral drugs metabolized via the same pathways. However, in vitro drug interaction activity may not translate to a clinically significant effect. Therefore, the effect of moringa leaf powder on the PK of nevirapine in HIV-infected people was investigated. Adult patients at steady-state dosing with nevirapine were admitted for 12-h intensive PK sampling following a 21-day herbal medicine washout. Blood sampling was repeated after 14 days of nevirapine and moringa (1.85 g leaf powder/day) co-administration. Nevirapine plasma concentrations were determined by liquid chromatography-tandem mass spectrometry. To assess the effect of moringa on nevirapine PK, the change in nevirapine area under the plasma concentration-time curve (AUC) was determined. The mean difference in pre- and post-moringa nevirapine, maximum concentration (C max ) and concentration at 12 h (C 12h ) were also calculated. The PK parameters were compared by assessing the post/pre geometric mean ratios (GMRs) and associated 90% confidence intervals (CIs). Pharmacokinetics analyses were performed on the results from 11 participants for whom complete data were obtained. The post/pre GMRs and associated 90% CIs for nevirapine were 1.07 (1.00-1.14) for the AUC; 1.06 (0.98-1.16) for C max and 1.03 (0.92-1.16) for C 12h . Co-administration of Moringa oleifera Lam. leaf powder at the traditional dose did not significantly alter the steady-state PK of nevirapine. Trial registration number NCT01410058 (ClinicalTrials.gov).

  20. Reversal of atherogenic lipoprotein profile in HIV-1 infected patients with lipodystrophy after replacing protease inhibitors by nevirapine

    NARCIS (Netherlands)

    Negredo, Eugenia; Ribalta, Josep; Paredes, Roger; Ferré, Raimón; Sirera, Guillem; Ruiz, Lidia; Salazar, Juliana; Reiss, Peter; Masana, Lluís; Clotet, Bonaventura

    2002-01-01

    Background: The widespread use of protease inhibitors (PI) has been associated with abnormalities in the lipid profile of HIV-1-infected patients. Treatment simplification approaches in which PI are replaced by nevirapine (NVP) have been shown to improve PI-related toxicity. Objective: To assess the

  1. Brief report: enzyme inducers reduce elimination half-life after a single dose of nevirapine in healthy women.

    NARCIS (Netherlands)

    L'homme, R.F.A.; Dijkema, T.; Ven, A.J.A.M. van der; Burger, D.M.

    2006-01-01

    OBJECTIVE: Single-dose nevirapine (SD-NVP) to prevent mother-to-child transmission (MTCT) of HIV is associated with development of NVP resistance, probably because of its long half-life in combination with a low genetic barrier to resistance. The objective of this study was to find enzyme inducers

  2. The steady-state pharmacokinetics of nevirapine during once daily and twice daily dosing in HIV-1-infected individuals

    NARCIS (Netherlands)

    van Heeswijk, R. P.; Veldkamp, A. I.; Mulder, J. W.; Meenhorst, P. L.; Wit, F. W.; Lange, J. M.; Danner, S. A.; Foudraine, N. A.; Kwakkelstein, M. O.; Reiss, P.; Beijnen, J. H.; Hoetelmans, R. M.

    2000-01-01

    OBJECTIVE: To investigate and to compare the steady-state plasma pharmacokinetics of nevirapine in a dosing regimen of 400 mg once daily versus 200 mg twice daily in HIV-1-infected individuals. DESIGN: Open-label, randomized, cross-over study. METHODS: Twenty HIV-1-infected individuals who already

  3. The efficacy, pharmacokinetics, safety and cardiovascular risks of switching nevirapine to rilpivirine in HIV-1 patients: the RPV switch study

    NARCIS (Netherlands)

    Rokx, C.; Blonk, M.; Verbon, A.; Burger, D.M.; Rijnders, B.J.

    2014-01-01

    INTRODUCTION: Nevirapine (NVP) induces cytochrome P450 3A4 by which rilpivirine (RPV) is metabolized. Switching NVP to RPV could result in decreased RPV exposure with subsequent virological failure and dyslipidemia because NVP is regarded as the least dyslipidemic, non-nucleoside, reverse

  4. Couples' voluntary counselling and testing and nevirapine use in antenatal clinics in two African capitals: a prospective cohort study.

    Science.gov (United States)

    Conkling, Martha; Shutes, Erin L; Karita, Etienne; Chomba, Elwyn; Tichacek, Amanda; Sinkala, Moses; Vwalika, Bellington; Iwanowski, Melissa; Allen, Susan A

    2010-03-15

    With the accessibility of prevention of mother to child transmission (PMTCT) services in sub-Saharan Africa, more women are being tested for HIV in antenatal care settings. Involving partners in the counselling and testing process could help prevent horizontal and vertical transmission of HIV. This study was conducted to assess the feasibility of couples' voluntary counseling and testing (CVCT) in antenatal care and to measure compliance with PMTCT. A prospective cohort study was conducted over eight months at two public antenatal clinics in Kigali, Rwanda, and Lusaka, Zambia. A convenience sample of 3625 pregnant women was enrolled. Of these, 1054 women were lost to follow up. The intervention consisted of same-day individual voluntary counselling and testing (VCT) and weekend CVCT; HIV-positive participants received nevirapine tablets. In Kigali, nevirapine syrup was provided in the labour and delivery ward; in Lusaka, nevirapine syrup was supplied in pre-measured single-dose syringes. The main outcome measures were nurse midwife-recorded deliveries and reported nevirapine use. In eight months, 1940 women enrolled in Kigali (984 VCT, 956 CVCT) and 1685 women enrolled in Lusaka (1022 VCT, 663 CVCT). HIV prevalence was 14% in Kigali, and 27% in Lusaka. Loss to follow up was more common in Kigali than Lusaka (33% vs. 24%, p = 0.000). In Lusaka, HIV-positive and HIV-negative women had significantly different loss-to-follow-up rates (30% vs. 22%, p = 0.002). CVCT was associated with reduced loss to follow up: in Kigali, 31% of couples versus 36% of women testing alone (p = 0.011); and in Lusaka, 22% of couples versus 25% of women testing alone (p = 0.137). Among HIV-positive women with follow up, CVCT had no impact on nevirapine use (86-89% in Kigali; 78-79% in Lusaka). Weekend CVCT, though new, was feasible in both capital cities. The beneficial impact of CVCT on loss to follow up was significant, while nevirapine compliance was similar in women tested alone or with

  5. Nevirapine resistance and breast-milk HIV transmission: effects of single and extended-dose nevirapine prophylaxis in subtype C HIV-infected infants.

    Directory of Open Access Journals (Sweden)

    Anitha Moorthy

    Full Text Available Daily nevirapine (NVP prophylaxis to HIV-exposed infants significantly reduces breast-milk HIV transmission. We assessed NVP-resistance in Indian infants enrolled in the "six-week extended-dose nevirapine" (SWEN trial who received single-dose NVP (SD-NVP or SWEN for prevention of breast-milk HIV transmission but who also acquired subtype C HIV infection during the first year of life.Standard population sequencing and cloning for viral subpopulations present at > or =5% frequency were used to determine HIV genotypes from 94% of the 79 infected Indian infants studied. Timing of infection was defined based on when an infant's blood sample first tested positive for HIV DNA. SWEN-exposed infants diagnosed with HIV by six weeks of age had a significantly higher prevalence of NVP-resistance than those who received SD-NVP, by both standard population sequencing (92% of 12 vs. 38% of 29; p = 0.002 and low frequency clonal analysis (92% of 12 vs. 59% of 29; p = 0.06. Likelihood of infection with NVP-resistant HIV through breast-milk among infants infected after age six weeks was substantial, but prevalence of NVP-resistance did not differ among SWEN or SD-NVP exposed infants by standard population sequencing (15% of 13 vs. 15% of 20; p = 1.00 and clonal analysis (31% of 13 vs. 40% of 20; p = 0.72. Types of NVP-resistance mutations and patterns of persistence at one year of age were similar between the two groups. NVP-resistance mutations did differ by timing of HIV infection; the Y181C variant was predominant among infants diagnosed in the first six weeks of life, compared to Y188C/H during late breast-milk transmission.Use of SWEN to prevent breast-milk HIV transmission carries a high likelihood of resistance if infection occurs in the first six weeks of life. Moreover, there was a continued risk of transmission of NVP-resistant HIV through breastfeeding during the first year of life, but did not differ between SD-NVP and SWEN groups. As with SD-NVP, the

  6. Considerable variation of trough β-lactam concentrations in older adults hospitalized with infection—a prospective observational study

    OpenAIRE

    Hatti, Malini; Solomonidi, Nikolitsa; Odenholt, Inga; Tham, Johan; Resman, Fredrik

    2018-01-01

    In older adults, few studies confirm that adequate concentrations of antibiotics are achieved using current dosage regimens of intravenous β-lactam antibiotics. Our objective was to investigate trough concentrations of cefotaxime, meropenem, and piperacillin in older adults hospitalized with infection. We included 102 patients above 70 years of age. Total trough antibiotic concentrations were measured and related to suggested target intervals. Information on antibiotic dose, patient character...

  7. Are Vancomycin Trough Concentrations Adequate for Optimal Dosing?

    Science.gov (United States)

    Youn, Gilmer; Jones, Brenda; Jelliffe, Roger W.; Drusano, George L.; Rodvold, Keith A.; Lodise, Thomas P.

    2014-01-01

    The current vancomycin therapeutic guidelines recommend the use of only trough concentrations to manage the dosing of adults with Staphylococcus aureus infections. Both vancomycin efficacy and toxicity are likely to be related to the area under the plasma concentration-time curve (AUC). We assembled richly sampled vancomycin pharmacokinetic data from three studies comprising 47 adults with various levels of renal function. With Pmetrics, the nonparametric population modeling package for R, we compared AUCs estimated from models derived from trough-only and peak-trough depleted versions of the full data set and characterized the relationship between the vancomycin trough concentration and AUC. The trough-only and peak-trough depleted data sets underestimated the true AUCs compared to the full model by a mean (95% confidence interval) of 23% (11 to 33%; P = 0.0001) and 14% (7 to 19%; P vancomycin MIC is 1 mg/liter, approximately 60% are expected to have a trough concentration below the suggested minimum target of 15 mg/liter for serious infections, which could result in needlessly increased doses and a risk of toxicity. Our data indicate that adjustment of vancomycin doses on the basis of trough concentrations without a Bayesian tool results in poor achievement of maximally safe and effective drug exposures in plasma and that many adults can have an adequate vancomycin AUC with a trough concentration of <15 mg/liter. PMID:24165176

  8. Peripartum nevirapine exposure and subsequent clinical outcomes among HIV-infected women receiving antiretroviral therapy for at least 12 months.

    Science.gov (United States)

    Chintu, Namwinga; Giganti, Mark J; Putta, Nande B; Sinkala, Moses; Sadoki, Ebedy; Stringer, Elizabeth M; Stringer, Jeffrey S A; Chi, Benjamin H

    2010-07-01

    Prior exposure to intrapartum/neonatal nevirapine (NVP) is associated with compromised virologic treatment outcomes once non-nucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral therapy (ART) is initiated. We examined the longer-term clinical outcomes in a programmatic setting. We compared post-12 month mortality and clinical treatment failure (defined by WHO clinical and immunologic criteria) among women with and without prior NVP exposure in Lusaka, Zambia. Between April 2004 and July 2006, 6740 women initiated an NNRTI-containing regimen. At 12 months, 5172 (78%) remained active and were included in this analysis. Of these, 596 (12%) reported prior NVP exposure, whose time from exposure to ART initiation was: 12 months for 37%, unknown for 39%. Overall, women with prior NVP exposure trended towards increased survival (adjusted hazard ratio [AHR]: 0.53; 95% confidence interval [CI]: 0.27-1.06, P = 0.07) and towards increased hazard of clinical treatment failure (AHR: 1.18; 95% CI: 0.95-1.47, P = 0.14), particularly those with exposure for <6 months (AHR: 1.52; 95% CI: 0.94-2.45, P = 0.09). Prior NVP exposure appeared to increase risk for clinical treatment failure after 12 months of follow-up, but this finding did not reach statistical significance. With growing evidence linking recent NVP exposure to virologic failure, optimized monitoring algorithms should be considered for women with starting NNRTI-based ART. The association between prior NVP exposure and improved survival has not been previously shown and may be a result of residual confounding around health-seeking behaviours.

  9. Nevirapine Use to Reduce Mother-To-Child Transmission of HIV in Canada

    Directory of Open Access Journals (Sweden)

    Committee for Canadian Paediatric AIDS Research Group

    2001-01-01

    Full Text Available Nevirapine (NVP is a non-nucleoside reverse transcriptase inhibitor (NNRTI that is used to treat adults and children with human immunodeficiency virus (HIV infection. The drug was licensed in Canada in September 1998 and has been widely used in combination antiretroviral therapy regimens, usually along with two nucleoside reverse transcriptase inhibitors. NVP is, generally, well tolerated; however, up to 20% of patients may develop rash, with a severe rash occurring in 6% of patients and Stevens-Johnson syndrome reported in 0.5% of patients. A large number of NNRTI mutations have been documented, and a single mutation, K103N, confers a degree of broad NNRTI resistance. Distinctions occur in resistance patterns to different NNRTIs (1.

  10. Effect of Nevirapine Toxicity on Choice of Perinatal HIV Prevention Strategies

    Science.gov (United States)

    Stringer, Jeffrey S. A.; Sinkala, Moses; Rouse, Dwight J.; Goldenberg, Robert L.; Vermund, Sten H.

    2002-01-01

    Objectives. This study evaluated the validity of concerns about the toxicity of nevirapine (NVP) that have delayed its implementation as a perinatal HIV prevention strategy. Methods. A decision analysis model compared 3 strategies: single-dose NVP, short-course zidovudine (ZDV), and no intervention. Results. NVP would prevent more deaths than ZDV and no intervention as long as the rate of NVP toxicity did not exceed, respectively, 9 times that observed in the earlier NVP clinical trial and 42 times that observed in the clinical trial. NVP would be economically preferable to ZDV as long as the rate of toxicity did not exceed 22 times that observed in the clinical trial. Conclusions. Field implementation of NVP should not be delayed by concerns about its toxicity. (Am J Public Health. 2002;92:365–366) PMID:11867311

  11. Alleviate Cellular Congestion Through Opportunistic Trough Filling

    Directory of Open Access Journals (Sweden)

    Yichuan Wang

    2014-04-01

    Full Text Available The demand for cellular data service has been skyrocketing since the debut of data-intensive smart phones and touchpads. However, not all data are created equal. Many popular applications on mobile devices, such as email synchronization and social network updates, are delay tolerant. In addition, cellular load varies significantly in both large and small time scales. To alleviate network congestion and improve network performance, we present a set of opportunistic trough filling schemes that leverage the time-variation of network congestion and delay-tolerance of certain traffic in this paper. We consider average delay, deadline, and clearance time as the performance metrics. Simulation results show promising performance improvement over the standard schemes. The work shed lights on addressing the pressing issue of cellular overload.

  12. Petroleum resources assessment of the Okinawa Trough

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jae Ho; Kwak, Young Hoon; Bong, Pil Yoon; Son, Jin Dam; Cheong, Tae Jin; Lee, Ho Young; Ryu, Byung Jae; Son, Byeong Kook; Hwang, In Gul; Kwon, Young Ihn; Lee, Yong Joo; Kim, Hag Ju; Yi, Sung Soog; Park, Kwan Soon; Park, Keun Pil; Shin, Chang Soo; Sunwoo, Don [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    The hydrocarbon potential has been evaluated for the Tertiary strata in the northwestern margin of the Okinawa Trough on the basis of the pale-ontological, petrological, geochemical data from two wells (Nikkan 8-9 and JDZ 7-3), and geophysical data. Abundant marine micro-fossils such as foraminifera, calcareous nannofossils and dinocysts were yielded in the sedimentary section of the above wells. Abundant palynomorphs originated from nearby onshore are also encountered. Based on nannofossils, the bio-stratigraphic zones from NN12 (Amaurolithus tricorniculatus Zone) to NN19 (Pseudoemiliania lacunosa Zone) are established. The sedimentary sequences are divided by local unconformity into Lower and Upper Groups, the ages of which are Late Miocene and Pliocene to Pleistocene, respectively. According to the geochemical analysis results, it is hard to expect a source rock that can generate enough hydrocarbons necessary for migration in the drilled intervals. Even though the thermal maturity reached the oil generation zone in the penetrated intervals, the calculation by the program GENEX of BEICIP shows that the amount of the generated hydrocarbons is not enough for the migration. A good source rock may be expected in the depth deeper than 4300 m horizon. Analysis of over 3300 Line-km of multichannel seismic data integrated with 2 well data serves to detail the structural and stratigraphic evolution of the western margin of the Okinawa Trough, offshore southern part of Korea peninsula. The overall tectonic style is characterized by a series of half-Graben and tilted fault blocks bounded by listric faults. Tectonics of the rift phase have been established on the basis of structural and stratigraphic analyses of depositional sequences and their seismic expressions. The potential hydrocarbon traps associated with titled fault block, fault and roll-over structure exist. (author). 44 refs.

  13. Experimental Investigation of Flow trough a Mechanical Heart Valve

    Science.gov (United States)

    Haji-Esmaeili, Farida; Oshkai, Peter

    2006-11-01

    Turbulent flow trough a model of a mechanical heart valve is investigated using digital particle image velocimetry. The valve leaflets are represented by flat plates mounted in a duct. The emphasis is on the effect of the valve design on the platelet activation state associated with the resulting flow field. Global quantitative images corresponding to multiple planes of data acquisition provide insight into the three-dimensional nature of the flow. Turbulent flow structures including jet-like regions and shed vortices are characterized in terms of patterns of instantaneous and time-averaged velocity, vorticity, and streamline topology. Potential of bileaflet heart valves for being thrombogenic is assessed by quantitative comparison of the associated flow fields in terms of maximum values of turbulent stresses and platelet activation states.

  14. Molecular Cytogenetics in Trough Shells (Mactridae, Bivalvia: Divergent GC-Rich Heterochromatin Content

    Directory of Open Access Journals (Sweden)

    Daniel García-Souto

    2016-08-01

    Full Text Available The family Mactridae is composed of a diverse group of marine organisms, commonly known as trough shells or surf clams, which illustrate a global distribution. Although this family includes some of the most fished and cultured bivalve species, their chromosomes are poorly studied. In this work, we analyzed the chromosomes of Spisula solida, Spisula subtruncata and Mactra stultorum by means of fluorochrome staining, C-banding and fluorescent in situ hybridization using 28S ribosomal DNA (rDNA, 5S rDNA, H3 histone gene and telomeric probes. All three trough shells presented 2n = 38 chromosomes but different karyotype compositions. As happens in most bivalves, GC-rich regions were limited to the nucleolus organizing regions in Spisula solida. In contrast, many GC-rich heterochromatic bands were detected in both Spisula subtruncata and Mactra stultorum. Although the three trough shells presented single 5S rDNA and H3 histone gene clusters, their chromosomal locations differed. Regarding major rDNA clusters, while Spisula subtruncata presented a single cluster, both Spisula solida and Mactra stultorum showed two. No evidence of intercalary telomeric signals was detected in these species. The molecular cytogenetic characterization of these taxa will contribute to understanding the role played by chromosome changes in the evolution of trough shells.

  15. Investigation on the dynamic behaviour of a parabolic trough power plant during strongly cloudy days

    International Nuclear Information System (INIS)

    Al-Maliki, Wisam Abed Kattea; Alobaid, Falah; Starkloff, Ralf; Kez, Vitali; Epple, Bernd

    2016-01-01

    Highlights: • A detailed dynamic model of a parabolic trough solar thermal power plant is done. • Simulated results are compared to the experimental data from the real power plant. • Discrepancy between model result and real data is caused by operation strategy. • The model strategy increased the operating hours of power plant by around 2.5–3 h. - Abstract: The objective of this study is the development of a full scale dynamic model of a parabolic trough power plant with a thermal storage system, operated by the Actividades de Construcción y Servicios Group in Spain. The model includes solar field, thermal storage system and the power block and describes the heat transfer fluid and steam/water paths in detail. The parabolic trough power plant is modelled using Advanced Process Simulation Software (APROS). To validate the model, the numerical results are compared to the measured data, obtained from “Andasol II” during strongly cloudy periods in the summer days. The comparisons show a qualitative agreement between the dynamic simulation model and the measurements. The results confirm that the thermal storage enables the parabolic trough power plant to provide a constant power rate when the storage energy discharge is available, despite significant oscillations in the solar radiation.

  16. Strategies for nevirapine initiation in HIV-infected children taking pediatric fixed-dose combination "baby pills" in Zambia: a randomized controlled trial.

    Science.gov (United States)

    Mulenga, V; Cook, A; Walker, A S; Kabamba, D; Chijoka, C; Ferrier, A; Kalengo, C; Kityo, C; Kankasa, C; Burger, D; Thomason, M; Chintu, C; Gibb, D M

    2010-11-01

    Fixed-dose combination scored dispersible stavudine, lamivudine, and nevirapine minitablets (Triomune Baby and Junior; Cipla Ltd) are simpler and cheaper than liquid formulations and have correct dose ratios for human immunodeficiency virus-infected children. However, they cannot be used for dose escalation (DE) of nevirapine. Children were randomized to initiate antiretroviral therapy with full-dose (FD) nevirapine (Triomune Baby or Junior in the morning and evening) versus DE (half-dose nevirapine for 14 days [Triomune in the morning and stavudine-lamivudine {Lamivir-S} in the evening], then FD), in accordance with World Health Organization weight-band dosing tables. The primary end point was nevirapine-related clinical or laboratory grade 3 or 4 adverse events (AEs). In total, 211 children (median [interquartile range {IQR}] age, 5 [ 2-9 ] years; median [IQR] CD4 cell percentage, 13% [8%-18%]) were enrolled and followed up for a median (IQR) of 92 (68-116) weeks. There were 31 grade 3 or 4 AEs that were definitely/probably or uncertainly related to nevirapine in the FD group (18.0 per 100 child-years), compared with 29 in the DE group (16.5 per 100 child-years) (incidence rate ratio, 1.09; 95% confidence interval, 0.63–1.87; P = .74). All were asymptomatic; 11 versus 3 were single grade 3 or 4 elevations in alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels, all of which resolved without a change in nevirapine dose or interruption. Thirteen (12%) FD versus 2 (2%) DE children had grade 1 (2 in FD) or grade 2 (11 in FD and 2 in DE) rashes. Three (2 in FD and 1 in DE) substituted efavirenz, 3 (FD) continued FD nevirapine, and 9 (8 in FD and 1 in DE) temporarily interrupted nevirapine, followed by successful DE. Predictors of nevirapine rash were older age (P = .003) and higher CD4 cell count for age (P = .03). Twenty-two children died (12 in FD and 10 in DE), 1 FD and 5 DE children at dose Triomune or efavirenz substitution. Current

  17. Effect of Lopinavir and Nevirapine Concentrations on Viral Outcomes in Protease Inhibitor-experienced HIV-infected Children.

    Science.gov (United States)

    Moholisa, Retsilisitsoe R; Schomaker, Michael; Kuhn, Louise; Castel, Sandra; Wiesner, Lubbe; Coovadia, Ashraf; Strehlau, Renate; Patel, Faeezah; Pinillos, Francoise; Abrams, Elaine J; Maartens, Gary; McIlleron, Helen

    2016-12-01

    Adequate exposure to antiretroviral drugs is necessary to achieve and sustain viral suppression. However, the target antiretroviral concentrations associated with long-term viral suppression have not been adequately defined in children. We assessed the relationship between plasma lopinavir or nevirapine concentrations and the risk of subsequent viremia in children initially suppressed on antiretroviral therapy. After an induction phase of antiretroviral treatment, 195 children with viral suppression (viral load ≤400 copies/mL) were randomized to continue a lopinavir/ritonavir-based regimen or to switch to a nevirapine-based regimen (together with lamivudine and stavudine). Viral load and lopinavir or nevirapine concentrations were measured at clinic visits 4, 8, 12, 16, 20, 24, 36, 52, 64 and 76 weeks post randomization. Cox multiple failure event models were used to estimate the effects of drug concentrations on the hazard of viremia (viral load >50 copies/mL) RESULTS:: At randomization, the median (interquartile range) age, CD4 T-Lymphocyte percentage, weight-for-age and weight-for-height z scores were 19 (16-24) months, 29% (23-37), -0.6 (-1.3 to 0.2) and -3.2 (-4.1 to -2.1), respectively. The proportion of children with viral load 51-400 copies/mL at randomization was 43%. The hazard of subsequent viremia during follow-up was increased for lopinavir concentrations <1 versus ≥1 mg/L [adjusted hazard ratio 0.62 (95% confidence interval, 0.40-0.94)] and for children with viral loads 51-400 copies/mL at randomization. Nevirapine concentrations were not significantly associated with subsequent viremia. Plasma lopinavir concentrations predicted viral outcomes in children receiving lopinavir-based antiretroviral therapy. Our findings support a minimum target concentration of ≥1 mg/L of lopinavir to ensure sustained viral suppression.

  18. Trough concentration of voriconazole and its relationship with efficacy and safety: a systematic review and meta-analysis.

    Science.gov (United States)

    Jin, Haiying; Wang, Tiansheng; Falcione, Bonnie A; Olsen, Keith M; Chen, Ken; Tang, Huilin; Hui, John; Zhai, Suodi

    2016-07-01

    The optimum trough concentration of voriconazole for clinical response and safety is controversial. The objective of this review was to determine the optimum trough concentration of voriconazole and evaluate its relationship with efficacy and safety. MEDLINE, EMBASE, ClinicalTrials.gov, the Cochrane Library and three Chinese literature databases were searched. Observational studies that compared clinical outcomes below and above the trough concentration cut-off value were included. We set the trough concentration cut-off value for efficacy as 0.5, 1.0, 1.5, 2.0 and 3.0 mg/L and for safety as 3.0, 4.0, 5.0, 5.5 and 6.0 mg/L. The efficacy outcomes were invasive fungal infection-related mortality, all-cause mortality, rate of successful treatment and rate of prophylaxis failure. The safety outcomes included incidents of hepatotoxicity, neurotoxicity and visual disorders. A total of 21 studies involving 1158 patients were included. Compared with voriconazole trough concentrations of >0.5 mg/L, levels of 3.0, >4.0, >5.5 and >6.0 mg/L. The incidence of neurotoxicity was significantly increased with trough concentrations >4.0 and >5.5 mg/L. A voriconazole level of 0.5 mg/L should be considered the lower threshold associated with efficacy. A trough concentration >3.0 mg/L is associated with increased hepatotoxicity, particularly for the Asian population, and >4.0 mg/L is associated with increased neurotoxicity. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

  19. Cobbles in Troughs Between Meridiani Ripples

    Science.gov (United States)

    2006-01-01

    As NASA's Mars Exploration Rover Opportunity continues to traverse from 'Erebus Crater' toward 'Victoria Crater,' the rover navigates along exposures of bedrock between large, wind-blown ripples. Along the way, scientists have been studying fields of cobbles that sometimes appear on trough floors between ripples. They have also been studying the banding patterns seen in large ripples. This view, obtained by Opportunity's panoramic camera on the rover's 802nd Martian day (sol) of exploration (April 27, 2006), is a mosaic spanning about 30 degrees. It shows a field of cobbles nestled among wind-driven ripples that are about 20 centimeters (8 inches) high. The origin of cobble fields like this one is unknown. The cobbles may be a lag of coarser material left behind from one or more soil deposits whose finer particles have blown away. The cobbles may be eroded fragments of meteoritic material, secondary ejecta of Mars rock thrown here from craters elsewhere on the surface, weathering remnants of locally-derived bedrock, or a mixture of these. Scientists will use the panoramic camera's multiple filters to study the rock types, variability and origins of the cobbles. This is an approximately true-color rendering that combines separate images taken through the panoramic camera's 753-nanometer, 535-nanometer and 432-nanometer filters.

  20. Parabolic Trough Solar Collector Initial Trials

    Directory of Open Access Journals (Sweden)

    Ghalya Pikra

    2012-03-01

    Full Text Available This paper discusses initial trials of parabolic trough solar collector (PTSC in Bandung. PTSC model consists of concentrator, absorber and tracking system. Concentrator designs are made with 2m aperture width, 6m length and 0.75m focal distance. The design is equipped with an automatic tracking system which is driven using 12V and 24Watt DC motor with 0.0125rpm rotational speed. Absorber/receiver is designed with evacuated tube type, with 1 inch core diameter and tube made of AISI304 and coated with black oxide, the outer tube is borosilicate glass with a 70 mm diameter and 1.5 m length. Working fluid stored in single type of thermal storage tank, a single phase with 37.7 liter volume. PTSC model testing carried out for 2 hours and 10 minutes produces heat output and input of 11.5 kW and 0.64 kW respectively. 

  1. The Rockall Trough, NE Atlantic: An Extinct Young Ocean Basin or a Failed Breakup Basin?

    Science.gov (United States)

    Roberts, Alan; Kusznir, Nick; Alvey, Andy

    2017-04-01

    We investigate the crustal structure and composition of the Rockall Trough which is located in the NE Atlantic to the west of Ireland and the UK. The Rockall Trough is a large extensional basin formed in the Early Cretaceous and has dimensions of approximately 250 km in width and 1000 km in length. It is one of several basins formed during the complex Mesozoic northward propagation of rifting, continental breakup and sea-floor spreading initiation of the North Atlantic; other adjacent basins formed at this time include the Porcupine Trough to its east and the East and West Orphan Basins on the Canadian conjugate margin. To investigate the crustal structure of the Rockall Trough we have used three independent analyses of available 2D and 3D data: 1. 3D gravity inversion, using public-domain gravity and sediment-thickness information, has produced maps of (i) depth to Moho, (ii) crustal thickness (figure 1) and (iii) stretching/thinning factor across both margins. 2. Gravity inversion as above, but using public-domain gravity data combined with new proprietary 2D sediment-thickness information, has produced a series of cross-sections which show (i) depth to Moho, (ii) crustal thickness and (iii) stretching/thinning factor across both margins 3. Geodynamic modelling, comprising 2D flexural backstripping and forward modelling, has been used to produce (i) estimates of stretching/thinning factor, (ii) whole-crustal cross-sections and (iii) predictions of palaeobathymetry through time along a series of project-specific transects. Our analysis of the Rockall Trough shows a rapid shallowing of crustal basement thicknesses on the flanks of the basin with central values of crustal thickness typically 8-10 km consistent with previously published seismic estimates. An important question is whether this thin crust is hyper-extended continental crust or proto-oceanic crust. Locally isolated patches of crustal thicknesses as low as 3km are observed which are consistent with the

  2. Optical analysis of a photovoltaic V-trough system installed in western India.

    Science.gov (United States)

    Maiti, Subarna; Sarmah, Nabin; Bapat, Pratap; Mallick, Tapas K

    2012-12-20

    The low concentrating photovoltaic (PV) system such as a 2× V-trough system can be a promising choice for enhancing the power output from conventional PV panels with the inclusion of thermal management. This system is more attractive when the reflectors are retrofitted to the stationary PV panels installed in a high aspect ratio in the north-south direction and are tracked 12 times a year manually according to preset angles, thus eliminating the need of diurnal expensive tracking. In the present analysis, a V-trough system facing exactly the south direction is considered, where the tilt angle of the PV panels' row is kept constant at 18.34°. The system is installed on the terrace of CSIR-Central Salt and Marine Chemicals Research Institute in Bhavnagar, Gujarat, India (21.47 N, 71.15 E). The dimension of the entire PV system is 9.64 m×0.55 m. The V-troughs made of anodized aluminum reflectors (70% specular reflectivity) had the same dimensions. An in-house developed; experimentally validated Monte Carlo ray-trace model was used to study the effect of the angular variation of the reflectors throughout a year for the present assembly. Results of the ray trace for the optimized angles showed the maximum simulated optical efficiency to be 85.9%. The spatial distribution of solar intensity over the 0.55 m dimension of the PV panel due to the V-trough reflectors was also studied for the optimized days in periods that included solstices and equinoxes. The measured solar intensity profiles with and without the V-trough system were used to calculate the actual optical efficiencies for several sunny days in the year, and results were validated with the simulated efficiencies within an average error limit of 10%.

  3. Floor cooler for floor trough of a nuclear reactor

    International Nuclear Information System (INIS)

    Friedrich, H.J.

    1985-01-01

    Cooling pipes are situated below the floor trough of a BWR, which are connected to the annular distribution or collection pipes. The distribution and collection pipes are connected by parallel hairpin pipes with involute shape to the centre of the floor trough. These hairpin pipes are situated in a lower plane than the annular distribution pipe to the centre and in a higher plane from the centre to the outer annular collector pipe. (orig./HP) [de

  4. Weak Lensing by Galaxy Troughs in DES Science Verification Data

    Energy Technology Data Exchange (ETDEWEB)

    Gruen, D. [Ludwig Maximilian Univ., Munich (Germany); Max Planck Inst. for Extraterrestrial Physics, Garching (Germany). et al.

    2015-09-29

    We measure the weak lensing shear around galaxy troughs, i.e. the radial alignment of background galaxies relative to underdensities in projections of the foreground galaxy field over a wide range of redshift in Science Verification data from the Dark Energy Survey. Our detection of the shear signal is highly significant (10σ–15σ for the smallest angular scales) for troughs with the redshift range z ϵ [0.2, 0.5] of the projected galaxy field and angular diameters of 10 arcmin…1°. These measurements probe the connection between the galaxy, matter density, and convergence fields. By assuming galaxies are biased tracers of the matter density with Poissonian noise, we find agreement of our measurements with predictions in a fiducial Λ cold dark matter model. Furthermore, the prediction for the lensing signal on large trough scales is virtually independent of the details of the underlying model for the connection of galaxies and matter. Our comparison of the shear around troughs with that around cylinders with large galaxy counts is consistent with a symmetry between galaxy and matter over- and underdensities. In addition, we measure the two-point angular correlation of troughs with galaxies which, in contrast to the lensing signal, is sensitive to galaxy bias on all scales. Finally, the lensing signal of troughs and their clustering with galaxies is therefore a promising probe of the statistical properties of matter underdensities and their connection to the galaxy field.

  5. Formulation, optimization, and evaluation of self-emulsifying drug delivery systems of nevirapine.

    Science.gov (United States)

    Chintalapudi, Ramprasad; Murthy, T E G K; Lakshmi, K Rajya; Manohar, G Ganesh

    2015-01-01

    The aim of the present study was to formulate and optimize the self-emulsifying drug delivery systems (SEDDS) of nevirapine (NVP) by use of 2(2) factorial designs to enhance the oral absorption of NVP by improving its solubility, dissolution rate, and diffusion profile. SEDDS are the isotropic mixtures of oil, surfactant, co-surfactant and drug that form oil in water microemulsion when introduced into the aqueous phase under gentle agitation. Solubility of NVP in different oils, surfactants, and co-surfactants was determined for the screening of excipients. Pseudo-ternary phase diagrams were constructed by the aqueous titration method, and formulations were developed based on the optimum excipient combinations with the help of data obtained through the maximum micro emulsion region containing combinations of oil, surfactant, and co-surfactant. The formulations of SEDDS were optimized by 2(2) factorial designs. The optimum formulation of SEDDS contains 32.5% oleic acid, 44.16% tween 20, and 11.9% polyethylene glycol 600 as oil, surfactant, and co-surfactant respectively. The SEDDS was evaluated for the following drug content, self-emulsification time, rheological properties, zeta potential, in vitro diffusion studies, thermodynamic stability studies, and in vitro dissolution studies. An increase in dissolution was achieved by SEDDS compared to pure form of NVP. Overall, this study suggests that the dissolution and oral bioavailability of NVP could be improved by SEDDS technology.

  6. Predictors of rapid HIV testing acceptance and successful nevirapine administration in Zambian labor wards.

    Science.gov (United States)

    Megazzini, Karen M; Chintu, Namwinga; Vermund, Sten H; Redden, David T; Krebs, Daniel W; Simwenda, Maureen; Tambatamba, Bushimbwa; Sinkala, Moses; Stringer, Jeffrey S A

    2009-10-01

    Provision of HIV testing in labor provides an opportunity to reach susceptible women and infants. As part of a cluster randomized trial of labor ward-based prevention of mother-to-child transmission services in Lusaka, Zambia, we determined predictors of testing acceptance and nevirapine (NVP) administration in labor. HIV counseling and testing were offered to women unaware of their HIV status. NVP was administered to women who tested positive, and an inert (calcium) tablet was provided to women who tested negative, to avoid stigmatization. Among the 2435 women who presented in labor, 393 (16%) were unaware of their HIV status, of whom 278 (71%) met eligibility criteria. We offered counseling to 217 (78%) of eligible women: 146 (67%) agreed, 82 (56%) of those counseled were tested for HIV, and 23 (28%) were seropositive. Testing rates were higher among primigravida women [adjusted odds ratio (AOR) 1.5; 95% confidence interval (CI): 1.1 to 2.1] and among those not offered HIV testing during their pregnancy (AOR 3.7; 95% CI: 2.8 to 5.1). Cervical dilation 1 hour (AOR 11.5; 95% CI: 4.5 to 29.2) and >2 hours (AOR 11.4; 95% CI: 4.7 to 27.5) before delivery. Labor ward HIV testing is feasible in this resource-limited setting.

  7. A Combined Optical, Thermal and Electrical Performance Study of a V-Trough PV System—Experimental and Analytical Investigations

    Directory of Open Access Journals (Sweden)

    Haitham M. Bahaidarah

    2015-04-01

    Full Text Available The objective of this study was to achieve higher efficiency of a PV system while reducing of the cost of energy generation. Concentration photovoltaics was employed in the present case as it uses low cost reflectors to enhance the efficiency of the PV system and simultaneously reduces the cost of electricity generation. For this purpose a V-trough integrated with the PV system was employed for low concentration photovoltaic (LCPV. Since the electrical output of the concentrating PV system is significantly affected by the temperature of the PV cells, the motivation of the research also included studying the ability to actively cool PV cells to achieve the maximum benefit. The optical, thermal and electrical performance of the V-trough PV system was theoretically modeled and validated with experimental results. Optical modeling of V-trough was carried out to estimate the amount of enhanced absorbed radiation. Due to increase in the absorbed radiation the module temperature was also increased which was predicted by thermal model. Active cooling techniques were studied and the effect of cooling was analyzed on the performance of V-trough PV system. With absorbed radiation and module temperature as input parameters, electrical modeling was carried out and the maximum power was estimated. For the V-trough PV system, experiments were performed for validating the numerical models and very good agreement was found between the two.

  8. GPS/acoustic Seafloor Geodetic Observations Near the Nankai Trough Axis

    Science.gov (United States)

    Tadokoro, K.; Yasuda, K.; Fujii, C.; Watanabe, T.; Nagai, S.

    2013-12-01

    The GPS/acoustic seafloor geodetic observation system, which uses precise acoustic ranging and kinematic GPS positioning techniques, has been developed as a useful tool for observing seafloor crustal deformations associated with plate convergence and with earthquakes that occurred in ocean area including the 2011 Tohoku-oki Earthquake of Mw 9.0. Our research group installed eight seafloor benchmarks for this observation system in source areas of anticipated major interplate earthquakes along the Nankai Trough, off southwestern Japan. We have performed campaign measurement for 4-8 years until the end of 2012. The error of displacement rate is almost 5 mm/y through the monitoring for more than four years. At the northern-most potion of the Nankai (Suruga) Trough, the observed steady horizontal displacement rate is 45 mm/y toward west. Also no significant velocity difference is observed across the trough, indicating strong interplate locking up to the shallowest segments. On the other hand, site velocities are 40 mm/y in the direction of N75W at the central region of the Nankai trough, 70-90 km landward from the trough axis. Although this result is the strong evidence for interplate locking, with coupling ratios of 60-80% on the basis of the back-slip model, it has no resolution for the interplate locking at the most-shallowest segments whose depths are 0-10 km. In other words, seaward up-dip limit of locked zone is never resolved from the present seafloor benchmark network [Tadokoro et al., 2012] . Large co-seismic slips larger than 40-50 m on the shallowest interplate segment [Ito et al., 2011; Fujii et al., 2011; Iinuma et al., 2012] are the cause of the unexpected high tsunami that has attacked the pacific coasts of the Tohoku region during the Tohoku-oki Earthquake; it is, therefore, essential to understand slip deficit or strain accumulation condition near the trench axis, also for the anticipated mega-thrust earthquake at the Nankai Trough. For this reason, we

  9. Simultaneous Sea-Level Oscillations in Japanese Bays Induced by the Tsunami of Nankai-Trough Earthquake

    Science.gov (United States)

    Oishi, Y.; Furumura, T.; Imamura, F.; Yamashita, K.; Sugawara, D.

    2016-12-01

    In this study, we investigate the response of bays to the tsunami of Nankai-trough earthquake based on tsunami simulations and demonstrate the possibility that sea-level oscillation of each bay, which is induced by an incident tsunami, interacts with those of other bays. Several major cities in Japan, including the capital, are located in the bays near the Nankai trough and it is assumed that these cities will be largely affected by the tsunamis caused by recurring large earthquakes at the trough. Therefore, it is very important for these populated cities to understand the mechanism and properties of the tsunami-induced oscillations that continue for a long time in bays to draw up evacuation plans. To investigate the response of bays for various tsunamis that may occur in the Nankai trough area, we distributed the tsunami sources that have the form of a 2-D Gaussian function around the Nankai trough. From simulations with these sources, it was found that strong oscillations of bay water occur when the source is located in the bay itself or when strong oscillations occur in other bays. For example, when the Tosa bay oscillates, the Tokyo bay that is 600 km away from the Tosa bay also oscillates. Among the bays around the Nankai trough, the Suruga bay, the deepest bay in Japan with a 2500-km depth, oscillates more strongly than other bays for most cases. To check the influence of the strong oscillations in the Suruga bay on other bays, we conducted tsunami simulations using a modified topography model in which the Suruga bay is artificially landfilled. As a consequence, the strength of oscillations in the adjacent bays are reduced by 20-30%, suggesting the large influence of the distinguished oscillation of the Suruga bay on these bays. We finally conducted tsunami simulations using the eleven Nankai-trough earthquake scenarios of the Central Disaster Prevention Council (CDPC) of Japan as tsunami sources, and the mutual relation regarding the strengths of

  10. The Salton Seismic Imaging Project (SSIP): Rift Processes and Earthquake Hazards in the Salton Trough (Invited)

    Science.gov (United States)

    Hole, J. A.; Stock, J. M.; Fuis, G. S.; Rymer, M. J.; Murphy, J. M.; Sickler, R. R.; Criley, C. J.; Goldman, M.; Catchings, R. D.; Ricketts, J. W.; Gonzalez-Fernandez, A.; Driscoll, N.; Kent, G.; Harding, A. J.; Klemperer, S. L.

    2009-12-01

    The Salton Seismic Imaging Project (SSIP) and coordinated projects will acquire seismic data in and across the Salton Trough in southern California and northern Mexico, including the Coachella, Imperial, and Mexicali Valleys. These projects address both rifting processes at the northern end of the Gulf of California extensional province and earthquake hazards at the southern end of the San Andreas Fault system. In the central Salton Trough, North American lithosphere appears to have been rifted completely apart. Based primarily on a 1979 seismic refraction project, the 20-22 km thick crust is apparently composed entirely of new crust added by magmatism from below and sedimentation from above. The new data will constrain the style of continental breakup, the role and mode of magmatism, the effects of rapid Colorado River sedimentation upon extension and magmatism, and the partitioning of oblique extension. The southernmost San Andreas Fault is considered at high risk of producing a large damaging earthquake, yet structures of the fault and adjacent basins are poorly constrained. To improve hazard models, SSIP will image the geometry of the San Andreas and Imperial Faults, structure of sedimentary basins in the Salton Trough, and three-dimensional seismic velocity of the crust and uppermost mantle. SSIP and collaborating projects have been funded by several different programs at NSF and the USGS. These projects include seven lines of land refraction and low-fold reflection data, airguns and OBS data in the Salton Sea, coordinated fieldwork for onshore-offshore and 3-D data, and a densely sampled line of broadband stations across the trough. Fieldwork is tentatively scheduled for 2010. Preliminary work in 2009 included calibration shots in the Imperial Valley that quantified strong ground motion and proved lack of harm to agricultural irrigation tile drains from explosive shots. Piggyback and complementary studies are encouraged.

  11. Tracing subducted sediment inputs to the Ryukyu arc-Okinawa Trough system: Evidence from thallium isotopes

    Science.gov (United States)

    Shu, Yunchao; Nielsen, Sune G.; Zeng, Zhigang; Shinjo, Ryuichi; Blusztajn, Jerzy; Wang, Xiaoyuan; Chen, Shuai

    2017-11-01

    Sediments are actively subducted in virtually every arc worldwide. However, quantifying their contributions to arc lavas and thereby establishing budgets of how sediments participate in slab-mantle interaction is challenging. In this contribution we use thallium (Tl) abundances and isotopic compositions of lavas from the Ryukyu arc (including south Kyushu) and its back-arc basin, Okinawa Trough, to investigate the influence of sediments from arc to back-arc. We also present extensive geochemical data for sediments and altered oceanic crust (AOC) outboard of the northern (DSDP Sites 296, 442B, 443 and 444) and central (DSDP Sites 294 and 295) part of the Ryukyu arc. The Tl isotopic compositions of sediments change systematically from lighter outboard of northern Ryukyu arc to heavier outboard of central Ryukyu arc. The feature reflects the dominance of terrigenous material and pelagic sedimentation outboard of the northern and central Ryukyu arc, respectively. Central and northern sections of Ryukyu arc and Okinawa Trough display larger range of Tl isotopic variation than southern section, which is consistent with more pelagic provenance for sediments outboard of central and northern Ryukyu arcs than that of expected sediments outboard of southern Ryukyu arc. Identical Tl, Sr, Nd and Pb isotope variations are found when comparing arc and back arc lavas, which indicates that sediments fluxes also account for the Tl isotopic variations in the Okinawa Trough lavas. Two-end-member mixing models of Tl with Pb, Sr and Nd isotopes require sediment inputs ofOkinawa Trough. Bulk mixing between mantle and sediment end members predict very similar sediment fluxes when using Tl, Sr, Nd and Pb isotopes, which indicates that fractionation of these elements must have happened after mixing between mantle and sediments. This conclusion is corroborated by model calculations of mixing between sediment melts with fractionated Sr/Nd ratios and mantle wedge, which show that no arc lava

  12. DEVELOPMENT AND PRELIMINARY TESTING OF A PARABOLIC TROUGH SOLAR WATER HEATER

    Directory of Open Access Journals (Sweden)

    O. A. Lasode

    2011-06-01

    Full Text Available Solar energy is a high-temperature, high-energy radiant energy source, with tremendous advantages over other alternative energy sources. It is a reliable, robust renewable resource which is largely undeveloped. The design and fabrication of parabolic trough solar water heater for water heating was executed. The procedure employed includes the design, construction and testing stages. The equipment which is made up of the reflector surface (curved mirror, reflector support, absorber pipe and a stand was fabricated using locally sourced materials. The results obtained. compared favourably with other research works in the literature. It depicts that employing a suitable design, selection of time of heating and proper focusing of the reflected rays to the focal spot region, solar radiation can efficiently be utilized for water heating in a tropical environment. This work presents a parabolic trough solar water heater as a suitable renewable energy technology for reducing water-heating costs.

  13. Performance Simulation Comparison for Parabolic Trough Solar Collectors in China

    Directory of Open Access Journals (Sweden)

    Jinping Wang

    2016-01-01

    Full Text Available Parabolic trough systems are the most used concentrated solar power technology. The operating performance and optical efficiency of the parabolic trough solar collectors (PTCs are different in different regions and different seasons. To determine the optimum design and operation of the parabolic trough solar collector throughout the year, an accurate estimation of the daily performance is needed. In this study, a mathematical model for the optical efficiency of the parabolic trough solar collector was established and three typical regions of solar thermal utilization in China were selected. The performance characteristics of cosine effect, shadowing effect, end loss effect, and optical efficiency were calculated and simulated during a whole year in these three areas by using the mathematical model. The simulation results show that the optical efficiency of PTCs changes from 0.4 to 0.8 in a whole year. The highest optical efficiency of PTCs is in June and the lowest is in December. The optical efficiency of PTCs is mainly influenced by the solar incidence angle. The model is validated by comparing the test results in parabolic trough power plant, with relative error range of 1% to about 5%.

  14. Reuse of single-dose nevirapine in subsequent pregnancies for the prevention of mother-to-child HIV transmission in Lusaka, Zambia: A cohort study

    Directory of Open Access Journals (Sweden)

    Sinkala Moses

    2008-12-01

    Full Text Available Abstract Background Single-dose nevirapine (SDNVP for the prevention of mother-to-child HIV transmission (PMTCT results in the selection of resistance mutants among HIV-infected mothers. The effects of these mutations on the efficacy of SDNVP use in a subsequent pregnancy are not well understood. Methods We compared risks of perinatal HIV transmission between multiparous women who had previously received a dose of SDNVP (exposed and those that had not (unexposed and who were given SDNVP for the index pregnancy within a PMTCT clinical study. We also compared transmission risks among exposed and unexposed women who had two consecutive pregnancies within the trial. Logistic regression modeling was used to adjust for possible confounders. Results Transmission risks did not differ between 59 SDNVP-exposed and 782 unexposed women in unadjusted analysis or after adjustment for viral load and disease stage (adjusted odds ratio 0.6, 95% confidence interval [CI] 0.2 to 2.0. Among 43 women who had two consecutive pregnancies during the study, transmission risks were 7% (95% CI 1% to 19% at both the first (unexposed and second (exposed delivery. The results were unchanged, if infant death was included as an outcome. Conclusion These data suggest that the efficacy of SDNVP may not be diminished when reused in subsequent pregnancies.

  15. Reuse of single-dose nevirapine in subsequent pregnancies for the prevention of mother-to-child HIV transmission in Lusaka, Zambia: a cohort study.

    Science.gov (United States)

    Walter, Jan; Kuhn, Louise; Kankasa, Chipepo; Semrau, Katherine; Sinkala, Moses; Thea, Donald M; Aldrovandi, Grace M

    2008-12-30

    Single-dose nevirapine (SDNVP) for the prevention of mother-to-child HIV transmission (PMTCT) results in the selection of resistance mutants among HIV-infected mothers. The effects of these mutations on the efficacy of SDNVP use in a subsequent pregnancy are not well understood. We compared risks of perinatal HIV transmission between multiparous women who had previously received a dose of SDNVP (exposed) and those that had not (unexposed) and who were given SDNVP for the index pregnancy within a PMTCT clinical study. We also compared transmission risks among exposed and unexposed women who had two consecutive pregnancies within the trial. Logistic regression modeling was used to adjust for possible confounders. Transmission risks did not differ between 59 SDNVP-exposed and 782 unexposed women in unadjusted analysis or after adjustment for viral load and disease stage (adjusted odds ratio 0.6, 95% confidence interval [CI] 0.2 to 2.0). Among 43 women who had two consecutive pregnancies during the study, transmission risks were 7% (95% CI 1% to 19%) at both the first (unexposed) and second (exposed) delivery. The results were unchanged, if infant death was included as an outcome. These data suggest that the efficacy of SDNVP may not be diminished when reused in subsequent pregnancies.

  16. Steady state bioequivalence of generic and innovator formulations of stavudine, lamivudine, and nevirapine in HIV-infected Ugandan adults.

    Directory of Open Access Journals (Sweden)

    Jayne Byakika-Tusiime

    Full Text Available Generic antiretroviral therapy is the mainstay of HIV treatment in resource-limited settings, yet there is little evidence confirming the bioequivalence of generic and brand name formulations. We compared the steady-state pharmacokinetics of lamivudine, stavudine and nevirapine in HIV-infected subjects who were receiving a generic formulation (Triomune or the corresponding brand formulations (Epivir, Zerit, and Viramune.An open-label, randomized, crossover study was carried out in 18 HIV-infected Ugandan subjects stabilized on Triomune-40. Subjects received lamivudine (150 mg, stavudine (40 mg, and nevirapine (200 mg in either the generic or brand formulation twice a day for 30 days, before switching to the other formulation. At the end of each treatment period, blood samples were collected over 12 h for pharmacokinetic analysis. The main outcome measures were the mean AUC(0-12h and C(max. Bioequivalence was defined as a geometric mean ratio between the generic and brand name within the 90% confidence interval of 0.8-1.25. The geometric mean ratios and the 90% confidence intervals were: stavudine C(max, 1.3 (0.99-1.71 and AUC(0-12h, 1.1 (0.87-1.38; lamivudine C(max, 0.8 (0.63-0.98 and AUC(0-12h, 0.8 (0.65-0.99; and nevirapine C(max, 1.1 (0.95-1.23 and AUC(0-12h, 1.1 (0.95-1.31. The generic formulation was not statistically bioequivalent to the brand formulations during steady state, although exposures were comparable. A mixed random effects model identified about 50% intersubject variability in the pharmacokinetic parameters.These findings provide support for the use of Triomune in resource-limited settings, although identification of the sources of intersubject variability in these populations is critical.

  17. Controlled-Source Seismic Imaging of Rift Processes and Earthquake Hazards in the Salton Trough

    Science.gov (United States)

    Hole, J. A.; Stock, J. M.; Fuis, G. S.

    2008-12-01

    The NSF MARGINS program, the NSF EarthScope program, and the U.S. Geological Survey have funded a large seismic refraction and reflection survey of the Salton Trough in southern California and northern Mexico, including the Coachella, Imperial, and Mexicali Valleys. The purpose of this presentation is to communicate plans for the seismic project and encourage synergy with piggyback and complementary studies. Fieldwork is tentatively scheduled for January 2010. The goals of the project include both rifting processes at the northern end of the Gulf of California extensional province and earthquake hazards at the southern end of the San Andreas Fault system. In the central Salton Trough, North American lithosphere appears to have been rifted completely apart. The 20-22 km thick crust is apparently composed entirely of new crust added by magmatism from below and sedimentation from above. The seismic survey will investigate the style of continental breakup, the role and mode of magmatism, the effects of rapid Colorado River sedimentation upon extension and magmatism, and the partitioning of oblique extension. The southernmost San Andreas Fault is considered at high risk of producing a large damaging earthquake, yet structure of the fault and adjacent basins are not currently well constrained. To improve hazard models, the seismic survey will image the structure of the San Andreas and Imperial Faults, structure of sedimentary basins in the Salton Trough, and three-dimensional seismic velocity of the crust and uppermost mantle.

  18. Risk of discontinuation of nevirapine due to toxicities in antiretroviral-naive and -experienced HIV-infected patients with high and low CD4+ T-cell counts

    DEFF Research Database (Denmark)

    Mocroft, Amanda; Staszewski, Schlomo; Weber, Rainer

    2007-01-01

    It is unknown whether the increased risk of toxicities in antiretroviral-naive HIV-infected patients initiating nevirapine-based (NVPc) combination antiretroviral therapy (cART) with high CD4+ T-cell counts is also observed when NVPc is initiated in cARTexperienced patients.......It is unknown whether the increased risk of toxicities in antiretroviral-naive HIV-infected patients initiating nevirapine-based (NVPc) combination antiretroviral therapy (cART) with high CD4+ T-cell counts is also observed when NVPc is initiated in cARTexperienced patients....

  19. Oral lesions associated with Nevirapine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis: A report of 10 cases.

    Science.gov (United States)

    Reddy, Ramana Bv; Shekar, P Chandra; Chandra, K Lalith Prakash; Aravind, Rs

    2013-09-01

    Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) are closely related severe, acute mucocutaneous reactions usually caused by drugs. They are acute life-threatening conditions and cause widespread necrosis of the epithelium. There is persistence of a high risk of SJS or TEN in relation to human immunodeficiency virus (HIV) infection associated with exposure to nevirapine (NVP). In this article, we present nine cases of SJS and one case of TEN in HIV-seropositive individuals who developed cutaneous, oral, ocular and genital lesions while being treated with NVP.

  20. Addition of single-dose tenofovir and emtricitabine to intrapartum nevirapine to reduce perinatal HIV transmission.

    Science.gov (United States)

    Chi, Benjamin H; Chintu, Namwinga; Cantrell, Ronald A; Kankasa, Chipepo; Kruse, Gina; Mbewe, Felistas; Sinkala, Moses; Smith, Peter J; Stringer, Elizabeth M; Stringer, Jeffrey S A

    2008-06-01

    To determine the impact of adjuvant single-dose peripartum tenofovir/emtricitabine (TDF/FTC) on intrapartum/early postpartum HIV transmission. In the setting of routine short-course zidovudine (ZDV) and peripartum nevirapine (NVP) for perinatal HIV prevention, participants were randomized to single-dose TDF (300 mg)/FTC (200 mg) or to no intervention in labor. Six-week infant HIV infection was compared according to actual-use drug regimens. Of 397 women randomized, 355 (89%) had infants who were alive and active at 6 weeks postpartum. Of these, 18 (5.1%) were infected in utero and 6 (1.8%) were infected intrapartum/early postpartum. Among the 243 who used ZDV and NVP, intrapartum/early postpartum transmission was not reduced among infants whose mothers received TDF/FTC compared with those who did not (2 of 123 [1.6%] vs. 3 of 109 [2.8%]; P = 0.67). Among the 49 infants whose mothers did not receive antenatal ZDV but who had confirmed NVP ingestion, transmission similarly did not differ (0 of 19 [0%] vs. 1 of 26 [3.4%]). TDF/FTC was not significantly associated with reduced overall transmission (odds ratio [OR] = 0.7, 95% confidence interval [CI]: 0.3 to 1.6), even when other antiretroviral drugs were considered (adjusted OR = 0.8, 95% CI: 0.3 to 1.8). Adjuvant peripartum single-dose TDF/FTC did not reduce perinatal transmission. Whether a higher dose might be effective remains unknown but should be studied in settings in which NVP is used without antenatal ZDV.

  1. Molten salt parabolic trough system with synthetic oil preheating

    Science.gov (United States)

    Yuasa, Minoru; Hino, Koichi

    2017-06-01

    Molten salt parabolic trough system (MSPT), which can heat the heat transfer fluid (HTF) to 550 °C has a better performance than a synthetic oil parabolic trough system (SOPT), which can heat the HTF to 400 °C or less. The utilization of HTF at higher temperature in the parabolic trough system is able to realize the design of a smaller size of storage tank and higher heat to electricity conversion efficiency. However, with MSPT there is a great amount of heat loss at night so it is necessary to circulate the HTF at a high temperature of about 290 °C in order to prevent solidification. A new MSPT concept with SOPT preheating (MSSOPT) has been developed to reduce the heat loss at night. In this paper, the MSSOPT system, its performance by steady state analysis and annual performance analysis are introduced.

  2. Federal technology alert. Parabolic-trough solar water heating

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    Parabolic-trough solar water heating is a well-proven renewable energy technology with considerable potential for application at Federal facilities. For the US, parabolic-trough water-heating systems are most cost effective in the Southwest where direct solar radiation is high. Jails, hospitals, barracks, and other facilities that consistently use large volumes of hot water are particularly good candidates, as are facilities with central plants for district heating. As with any renewable energy or energy efficiency technology requiring significant initial capital investment, the primary condition that will make a parabolic-trough system economically viable is if it is replacing expensive conventional water heating. In combination with absorption cooling systems, parabolic-trough collectors can also be used for air-conditioning. Industrial Solar Technology (IST) of Golden, Colorado, is the sole current manufacturer of parabolic-trough solar water heating systems. IST has an Indefinite Delivery/Indefinite Quantity (IDIQ) contract with the Federal Energy Management Program (FEMP) of the US Department of Energy (DOE) to finance and install parabolic-trough solar water heating on an Energy Savings Performance Contract (ESPC) basis for any Federal facility that requests it and for which it proves viable. For an ESPC project, the facility does not pay for design, capital equipment, or installation. Instead, it pays only for guaranteed energy savings. Preparing and implementing delivery or task orders against the IDIQ is much simpler than the standard procurement process. This Federal Technology Alert (FTA) of the New Technology Demonstration Program is one of a series of guides to renewable energy and new energy-efficient technologies.

  3. Prevalence of middle mesial canals in mandibular molars after guided troughing under high magnification: an in vivo investigation.

    Science.gov (United States)

    Azim, Adham A; Deutsch, Allan S; Solomon, Charles S

    2015-02-01

    A limited number of in vivo studies have discussed the prevalence of middle mesial canals in root canal systems of mandibular molars. The reported results have varied between 1% and 25%, with no detailed description of the depth and direction of troughing needed to identify such small canal orifices. The objective of the present study was to determine (1) the prevalence of a middle mesial canal before and after troughing by using a standardized troughing technique, (2) the pathway of the middle mesial canal in relation to the mesiobuccal (MB) and mesiolingual (ML) canals, and (3) its correlation with the patient's age. Ninety-one mandibular molars from 87 patients were included in this study. The patient's age and tooth number were recorded. After access cavity preparation, a standardized troughing technique was performed between MB and ML canals to search for a middle mesial canal by using a dental operating microscope. If a middle mesial canal was located, it was recorded as separate or as joining the MB or the ML canals. Results were statistically analyzed by using Z test and logistic regression. A middle mesial canal was found in 42 of 91 mandibular molars (46.2%). Six middle mesial canals were located after conventional access preparation (6.6%). The other 36 were located after standardized troughing (39.6%). The results were statistically significant (P magnification, troughing, and patient's age appeared to be determining factors in accessing the middle mesial canal. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Detailed Physical Trough Model for NREL's Solar Advisor Model: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M. J.; Blair, N.; Dobos, A.

    2010-10-01

    Solar Advisor Model (SAM) is a free software package made available by the National Renewable Energy Laboratory (NREL), Sandia National Laboratory, and the US Department of Energy. SAM contains hourly system performance and economic models for concentrating solar power (CSP) systems, photovoltaic, solar hot-water, and generic fuel-use technologies. Versions of SAM prior to 2010 included only the parabolic trough model based on Excelergy. This model uses top-level empirical performance curves to characterize plant behavior, and thus is limited in predictive capability for new technologies or component configurations. To address this and other functionality challenges, a new trough model; derived from physical first principles was commissioned to supplement the Excelergy-based empirical model. This new 'physical model' approaches the task of characterizing the performance of the whole parabolic trough plant by replacing empirical curve-fit relationships with more detailed calculations where practical. The resulting model matches the annual performance of the SAM empirical model (which has been previously verified with plant data) while maintaining run-times compatible with parametric analysis, adding additional flexibility in modeled system configurations, and providing more detailed performance calculations in the solar field, power block, piping, and storage subsystems.

  5. A common origin for ridge-and-trough terrain on icy satellites by sluggish lid convection

    Science.gov (United States)

    Barr, Amy C.; Hammond, Noah P.

    2015-12-01

    Ridge-and-trough terrain is a common landform on outer Solar System icy satellites. Examples include Ganymede's grooved terrain, Europa's gray bands, Miranda's coronae, and several terrains on Enceladus. The conditions associated with the formation of each of these terrains are similar: heat flows of order tens to a hundred milliwatts per meter squared, and deformation rates of order 10-16-10-12 s-1. Our prior work shows that the conditions associated with the formation of these terrains on Ganymede and the south pole of Enceladus are consistent with vigorous solid-state ice convection in a shell with a weak surface. We show that sluggish lid convection, an intermediate regime between the isoviscous and stagnant lid regimes, can create the heat flow and deformation rates appropriate for ridge and trough formation on a number of satellites, regardless of the ice shell thickness. For convection to deform their surfaces, the ice shells must have yield stresses similar in magnitude to the daily tidal stresses. Tidal and convective stresses deform the surface, and the spatial pattern of tidal cracking controls the locations of ridge-and-trough terrain.

  6. MONTI as continent catheterized stoma using serosal-lined trough "Ghoneim Abolenin" technique in ileocystoplasty

    Directory of Open Access Journals (Sweden)

    Mohammed T Sammour

    2011-01-01

    Full Text Available It is a great challenge to select and perform continent mechanism in a stoma for urinary reservoir. A new technique by combining MONTI ileal conduit with the serosal lined trough in order to achieve continent catheterizable stoma to the umbilicus as a part of augmentation ileocystoplasty. We applied serosal-lined trough as a continent mechanism with MONTI ileal tube in 12 years smart girl underwent ileocystoplasty for neuropathic bladder due to meylomeningocele in whom continence failed to be achieved by using Mitrofanoff with submucosal tunnel of the bladder as continent mechanism before, also the previous operation included left to right transuretero-ureterostomy, ureterocystoplasty and reimplantation of the right ureter. The patient became completely continent; she was able to do self-catheterization easily through the umbilical stoma using 16-French catheter and was able to wash the mucous easily. The capacity of the augmented bladder was 300ccs. She became independent from her mother and stopped using diapers, anticholinergic and antibiotics. Combining MONTI conduit with serosal-lined extramural valve trough (The Ghoneim technique is an effective continent technique and gives wider channel for catheterization and washing out the mucous.

  7. Tracking local control of a parabolic trough collector

    International Nuclear Information System (INIS)

    Ajona, J.I.; Alberdi, J.; Gamero, E.; Blanco, J.

    1992-01-01

    In the local control, the sun position related to the trough collector is measured by two photo-resistors. The provided electronic signal is then compared with reference levels in order to get a set of B logical signals which form a byte. This byte and the commands issued by a programmable controller are connected to the inputs of o P.R.O.M. memory which is programmed with the logical equations of the control system. The memory output lines give the control command of the parabolic trough collector motor. (Author)

  8. Parabolic-trough technology roadmap: A pathway for sustained commercial development and deployment of parabolic-trough technology

    International Nuclear Information System (INIS)

    David Kearney; Hank Price

    1999-01-01

    Technology roadmapping is a needs-driven technology planning process to help identify, select, and develop technology alternatives to satisfy a set of market needs. The DOE's Office of Power Technologies' Concentrating Solar Power (CSP) Program recently sponsored a technology roadmapping workshop for parabolic trough technology. The workshop was attended by an impressive cross section of industry and research experts. The goals of the workshop were to evaluate the market potential for trough power projects, develop a better understanding of the current state of the technology, and to develop a conceptual plan for advancing the state of parabolic trough technology. This report documents and extends the roadmap that was conceptually developed during the workshop

  9. Parabolic-Trough Technology Roadmap: A Pathway for Sustained Commercial Development and Deployment of Parabolic-Trough Technology

    Energy Technology Data Exchange (ETDEWEB)

    Price, H.; Kearney, D.

    1999-01-31

    Technology roadmapping is a needs-driven technology planning process to help identify, select, and develop technology alternatives to satisfy a set of market needs. The DOE's Office of Power Technologies' Concentrating Solar Power (CSP) Program recently sponsored a technology roadmapping workshop for parabolic trough technology. The workshop was attended by an impressive cross section of industry and research experts. The goals of the workshop were to evaluate the market potential for trough power projects, develop a better understanding of the current state of the technology, and to develop a conceptual plan for advancing the state of parabolic trough technology. This report documents and extends the roadmap that was conceptually developed during the workshop.

  10. Gas Turbine/Solar Parabolic Trough Hybrid Designs: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, C. S.; Ma, Z.; Erbes, M.

    2011-03-01

    A strength of parabolic trough concentrating solar power (CSP) plants is the ability to provide reliable power by incorporating either thermal energy storage or backup heat from fossil fuels. Yet these benefits have not been fully realized because thermal energy storage remains expensive at trough operating temperatures and gas usage in CSP plants is less efficient than in dedicated combined cycle plants. For example, while a modern combined cycle plant can achieve an overall efficiency in excess of 55%; auxiliary heaters in a parabolic trough plant convert gas to electricity at below 40%. Thus, one can argue the more effective use of natural gas is in a combined cycle plant, not as backup to a CSP plant. Integrated solar combined cycle (ISCC) systems avoid this pitfall by injecting solar steam into the fossil power cycle; however, these designs are limited to about 10% total solar enhancement. Without reliable, cost-effective energy storage or backup power, renewable sources will struggle to achieve a high penetration in the electric grid. This paper describes a novel gas turbine / parabolic trough hybrid design that combines solar contribution of 57% and higher with gas heat rates that rival that for combined cycle natural gas plants. The design integrates proven solar and fossil technologies, thereby offering high reliability and low financial risk while promoting deployment of solar thermal power.

  11. Parabolic troughs to increase the geothermal wells flow enthalpy

    Energy Technology Data Exchange (ETDEWEB)

    Lentz, Alvaro; Almanza, Rafael [Engineering Institute, National Autonomous University of Mexico, Building 12, Cuidad Universitaria, Mexico D.F., A.P. 70-472, C.P. 04510 (Mexico)

    2006-10-15

    This work investigates the feasibility of using parabolic trough solar field to increase the enthalpy from geothermal wells' flow in order to increase the steam tons; in addition, it is possible to prevent silica deposition in the geothermal process. The high levels of irradiance in Northwestern Mexico make it possible to integrate a solar-geothermal hybrid system that uses two energy resources to provide steam for the geothermal cycle, like the Cerro Prieto geothermal field. The plant consists of a geothermal well, a parabolic trough solar field in series, flash separator, steam turbine and condenser. Well '408' of Cerro Prieto IV has enthalpy of 1566kJ/kg and its quality must be increased by 10 points, which requires a {delta}h of 194.4kJ/kg. Under these considerations the parabolic troughs area required will be 9250m{sup 2}, with a flow of 92.4tons per hour (25.67kg/s). The solar field orientation is a N-S parabolic trough concentrator. The silica content in the Cerro Prieto geothermal brine causes problems for scaling at the power facility, so scale controls must be considered. (author)

  12. Performance Test of Parabolic Trough Solar Cooker for Indoor ...

    African Journals Online (AJOL)

    Bheema

    In the absence of new sustainable, cleaner, more efficient use of energy for cooking the number of people .... the solar cooker. For optimum utilization of the solar energy resource, the orientation of the parabolic trough is ..... Use of solar cooker can replace use of firewood, kerosene, LPG, and electric cooking. Depending on ...

  13. Ostracods from the yola arm, Upper Benue Trough, Nigeria ...

    African Journals Online (AJOL)

    A total of nine genera of ostracods from the Yola Arm in the north-east of Nigeria are described. The various species, though from outcrop sections, supplement the list from the Upper Benue Trough already reported from Ashaka quarry and borehole (BH 2340) of the Gongila and Pindiga Formations respectively.

  14. Parabolic Trough Solar Power for Competitive U.S. Markets

    International Nuclear Information System (INIS)

    Price, Henry W.

    1998-01-01

    Nine parabolic trough power plants located in the California Mojave Desert represent the only commercial development of large-scale solar power plants to date. Although all nine plants continue to operate today, no new solar power plants have been completed since 1990. Over the last several years, the parabolic trough industry has focused much of its efforts on international market opportunities. Although the power market in developing countries appears to offer a number of opportunities for parabolic trough technologies due to high growth and the availability of special financial incentives for renewables, these markets are also plagued with many difficulties for developers. In recent years, there has been some renewed interest in the U.S. domestic power market as a result of an emerging green market and green pricing incentives. Unfortunately, many of these market opportunities and incentives focus on smaller, more modular technologies (such as photovoltaics or wind power), and as a result they tend to exclude or are of minimum long-term benefit to large-scale concentrating solar power technologies. This paper looks at what is necessary for large-scale parabolic trough solar power plants to compete with state-of-the-art fossil power technology in a competitive U.S. power market

  15. Do leading indicators lead peaks more than troughs?

    NARCIS (Netherlands)

    R. Paap (Richard); R. Segers (René); D.J.C. van Dijk (Dick)

    2007-01-01

    textabstractWe develop a formal statistical approach to investigate the possibility that leading indicator variables have different lead times at business cycle peaks and troughs. For this purpose, we propose a novel Markov switching vector autoregressive model, where economic growth and leading

  16. Development and preliminary testing of a parabolic trough solar ...

    African Journals Online (AJOL)

    It depicts that employing a suitable design, selection of time of heating and proper focusing of the reflected rays to the focal spot region, solar radiation can efficiently be utilized for water heating in a tropical environment. This work presents a parabolic trough solar water heater as a suitable renewable energy technology for ...

  17. The relationship between trough concentration of vancomycin and ...

    African Journals Online (AJOL)

    Objectives. The incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections in intensive care units in Malaysia is significant. Invasive MRSA infections are commonly treated with vancomycin. In clinical practice, the serum vancomycin trough concentration is used as a surrogate marker of vancomycin efficacy.

  18. Gravity Anomalies Over The Gongola Arm, Upper Benue Trough ...

    African Journals Online (AJOL)

    A regional gravity survey of the Gongola Arm of the Benue trough was carried out with the aim of determining structures of interest. The results of the gravity interpretation showed that the area of study is characterized by negative Bouguer anomalies that trend in the NE-SW direction and range in value from -75 to -15 mGal ...

  19. The crustal structure along the Mbere trough in South Adamawa ...

    African Journals Online (AJOL)

    The Mbere Cretaceous trough is located in the southern part of the Adamawa province. A gravity interpretation based on data obtained from three NW-SE profiles on the residual anomaly map has been carried out using a 2.5D modelling program. Spectral analysis has been used to estimate the depth of geological ...

  20. Performance simulation of parabolic trough solar collector using two ...

    African Journals Online (AJOL)

    The Parabolic trough solar collector is considered as one of the most proven, mature and commercial concentrating solar systems implemented in arid and semi-arid regions for energy production. It focuses sunlight onto a solar receiver by using mirrors and is finally converted to a useful thermal energy by means of a heat ...

  1. Modeling, Simulation and Performance Evaluation of Parabolic Trough

    African Journals Online (AJOL)

    Mekuannint

    Mekuannint Mesfin and Abebayehu Assefa. Department of Mechanical Engineering. Addis Ababa University ... off design weather conditions as well. Keywords: Parabolic Trough Collector (PTC);. Heat Transfer ... of a conventional Rankine cycle power plant with solar fields that are used to increase the temperature of heat ...

  2. Inversion tectonics of the benue trough | Mamah | Global Journal of ...

    African Journals Online (AJOL)

    The Benue Trough, an aulacogen at the entrant of the Gulf of Guinea in Nigeria, has been historically studied from the concepts of ortho-mio-eu-geosynclines at outcrops and in the subsurface. Its structural evolution reveals a tectonic scenario compatible with Plate tectonic evolution of the Atlantic Ocean. Spreading was ...

  3. Incidence and risk factors of skin rashes and hepatotoxicity in HIV-infected patients receiving nevirapine-containing combination antiretroviral therapy in Taiwan

    Directory of Open Access Journals (Sweden)

    Yu-Tzu Tseng

    2014-12-01

    Conclusions: Abnormal liver function at baseline was significantly associated with skin rashes, while a higher CD4 count and the concurrent use of trimethoprim/sulfamethoxazole were associated with hepatotoxicity after the initiation of nevirapine-containing cART in HIV-infected Taiwanese patients.

  4. A comparison of the long-term durability of nevirapine, efavirenz and lopinavir in routine clinical practice in Europe: a EuroSIDA study

    DEFF Research Database (Denmark)

    Reekie, J; Reiss, P; Ledergerber, B

    2011-01-01

    The durability of combination antiretroviral therapy (cART) regimens can be measured as time to discontinuation because of toxicity or treatment failure, development of clinical disease or serious long-term adverse events. The aim of this analysis was to compare the durability of nevirapine...

  5. Strategies for nevirapine initiation in HIV-infected children taking pediatric fixed-dose combination "baby pills" in Zambia: a randomized controlled trial.

    NARCIS (Netherlands)

    Mulenga, V.; Cook, A.; Walker, A.S.; Kabamba, D.; Chijoka, C.; Ferrier, A.; Kalengo, C.; Kityo, C.; Kankasa, C.; Burger, D.M.; Thomason, M.; Chintu, C.; Gibb, D.M.

    2010-01-01

    BACKGROUND: Fixed-dose combination scored dispersible stavudine, lamivudine, and nevirapine minitablets (Triomune Baby and Junior; Cipla Ltd) are simpler and cheaper than liquid formulations and have correct dose ratios for human immunodeficiency virus-infected children. However, they cannot be used

  6.  Risk of discontinuation of nevirapine due to toxicities in antiretroviral naive and experienced HIV-infected patients with high and low CD4 counts

    DEFF Research Database (Denmark)

    Mocroft, A; Staszewski, S; Weber, R

    2007-01-01

    INTRODUCTION: It is unknown whether the increased risk of toxicities in antiretroviral-naive HIV-infected patients initiating nevirapine-based (NVPc) combination antiretroviral therapy (cART) with high CD4+ T-cell counts is also observed when NVPc is initiated in cARTexperienced patients. PATIENTS...

  7. Risk of discontinuation of nevirapine due to toxicities in antiretroviral-naive and -experienced HIV-infected patients with high and low CD4+ T-cell counts

    DEFF Research Database (Denmark)

    Mocroft, Amanda; Staszewski, Schlomo; Weber, Rainer

    2007-01-01

    It is unknown whether the increased risk of toxicities in antiretroviral-naive HIV-infected patients initiating nevirapine-based (NVPc) combination antiretroviral therapy (cART) with high CD4+ T-cell counts is also observed when NVPc is initiated in cARTexperienced patients....

  8. Real-time dynamic analysis for complete loop of direct steam generation solar trough collector

    International Nuclear Information System (INIS)

    Guo, Su; Liu, Deyou; Chu, Yinghao; Chen, Xingying; Shen, Bingbing; Xu, Chang; Zhou, Ling; Wang, Pei

    2016-01-01

    Highlights: • A nonlinear distribution parameter dynamic model has been developed. • Real-time local heat transfer coefficient and friction coefficient are adopted. • The dynamic behavior of the solar trough collector loop are simulated. • High-frequency chattering of outlet fluid flow are analyzed and modeled. • Irradiance disturbance at subcooled water region generates larger influence. - Abstract: Direct steam generation is a potential approach to further reduce the levelized electricity cost of solar trough. Dynamic modeling of the collector loop is essential for operation and control of direct steam generation solar trough. However, the dynamic behavior of fluid based on direct steam generation is complex because of the two-phase flow in the pipeline. In this work, a nonlinear distribution parameter model has been developed to model the dynamic behaviors of direct steam generation parabolic trough collector loops under either full or partial solar irradiance disturbance. Compared with available dynamic model, the proposed model possesses two advantages: (1) real-time local values of heat transfer coefficient and friction resistance coefficient, and (2) considering of the complete loop of collectors, including subcooled water region, two-phase flow region and superheated steam region. The proposed model has shown superior performance, particularly in case of sensitivity study of fluid parameters when the pipe is partially shaded. The proposed model has been validated using experimental data from Solar Thermal Energy Laboratory of University of New South Wales, with an outlet fluid temperature relative error of only 1.91%. The validation results show that: (1) The proposed model successfully outperforms two reference models in predicting the behavior of direct steam generation solar trough. (2) The model theoretically predicts that, during solar irradiance disturbance, the discontinuities of fluid physical property parameters and the moving back and

  9. Effect of water trough type on the drinking behaviour of pasture-based beef heifers.

    Science.gov (United States)

    Coimbra, P A D; Machado Filho, L C P; Nunes, P A; Hötzel, M J; de Oliveira, A G L; Cecato, U

    2010-01-01

    The objective of this study was to investigate the effects of different trough types on the water consumption and drinking behaviour of pasture-based beef heifers. Two trials were implemented with 32 beef heifers to test two different types of water troughs, namely a rectangular concrete trough (RC) and a round polyvinyl chloride water tank (PVC). In Trial 1, both troughs were simultaneously available to groups of four animals within eight paddocks. In Trial 2, the animals were distributed in pairs throughout 16 paddocks and, in a crossover design, were exposed to one type of trough at a time. In both trials, estimated water intake was per four animals. Number of drinking bouts, time spent drinking and amount of water intake from the RC and PVC trough were recorded in both trials. Data were statistically analysed by analysis of variance. In Trial 1, group and trough effect were in the model. In Trial 2, stage, pair and trough were tested. In Trial 1, where both types of troughs were available, animals had a higher number of drinking bouts (3.32 v. 0.57 ± 0.09; P PVC water tank, compared to the RC trough. In Trial 2, all groups drank more often (5.10 v. 3.28 ± 0.32; P PVC than from the RC trough. Thus, heifers not only prefer, but also drink more from a PVC water tank in comparison to a RC trough.

  10. Arctic Lena Trough -- NOT a Mid-Ocean Ridge

    Science.gov (United States)

    Snow, J. E.; Hellebrand, E.; Handt, A. V.; Nauret, F.; Gao, Y.; Feig, S.; Jovanovic, Z.

    2005-12-01

    The North American-Eurasian plate boundary traverses the Atlantic and Arctic oceans. Over most of that length, it is a Mid-Ocean Ridge that spreads between about 23 mm/yr (MAR) and 10 mm/yr (Gakkel Ridge) full rate. The northern MAR and the Gakkel ridge are connected by a deep linear feature called Lena Trough. Until about 10 million years ago, Lena Trough was not an oceanic domain at all, but a continental shear zone through a narrow isthmus of continental crust that connected the American and Eurasian plates. Its opening was, significantly, the most recent and final event in the separation of the North American from the Eurasian continent, and opened the gateway for deep water circulation between the Arctic and North Atlantic oceans. Models for the tectonic configuration of Lena Trough have until now differed only in the number and length of fracture zones and spreading segments thought to be present. Lena Trough is a deep fault-bounded basin with depths of 3800-4200m, and irregular, steep valley sides that are oblique to the spreading direction. Basement horst structures outcrop as sigmoidal ridges with steeply dipping sides project out of the valley floor, but these are not traceable to any parallel structures on either side. Ridge-orthogonal topography is simply absent (ie no segments trending parallel nor fracture zones perpendicular to Gakkel Ridge). Most faults trend approximately SSE-NNW, an obliquity with respect to Gakkel Ridge (SW-NE) of about 55 degrees. The basement ridges are composed nearly entirely of mantle peridotite, as are the valley walls. Only at the northern and southern extremities of Lena Trough do basalts appear at all. The Northern basalts show strong chemical affinities to those of Gakkel Ridge, and can be considered a part of the Gakkel volcanic system. The rare southernmost basalts, however, are quite unique. They are alkali basalts with K2O up to 2 weight percent, highly incompaitble element enriched and occupy a corner of isotope

  11. Outcomes for efavirenz versus nevirapine-containing regimens for treatment of HIV-1 infection: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Prinitha Pillay

    Full Text Available There is conflicting evidence and practice regarding the use of the non-nucleoside reverse transcriptase inhibitors (NNRTI efavirenz (EFV and nevirapine (NVP in first-line antiretroviral therapy (ART.We systematically reviewed virological outcomes in HIV-1 infected, treatment-naive patients on regimens containing EFV versus NVP from randomised trials and observational cohort studies. Data sources include PubMed, Embase, the Cochrane Central Register of Controlled Trials and conference proceedings of the International AIDS Society, Conference on Retroviruses and Opportunistic Infections, between 1996 to May 2013. Relative risks (RR and 95% confidence intervals were synthesized using random-effects meta-analysis. Heterogeneity was assessed using the I(2 statistic, and subgroup analyses performed to assess the potential influence of study design, duration of follow up, location, and tuberculosis treatment. Sensitivity analyses explored the potential influence of different dosages of NVP and different viral load thresholds.Of 5011 citations retrieved, 38 reports of studies comprising 114 391 patients were included for review. EFV was significantly less likely than NVP to lead to virologic failure in both trials (RR 0.85 [0.73-0.99] I(2 = 0% and observational studies (RR 0.65 [0.59-0.71] I(2 = 54%. EFV was more likely to achieve virologic success than NVP, though marginally significant, in both randomised controlled trials (RR 1.04 [1.00-1.08] I(2 = 0% and observational studies (RR 1.06 [1.00-1.12] I(2 = 68%.EFV-based first line ART is significantly less likely to lead to virologic failure compared to NVP-based ART. This finding supports the use of EFV as the preferred NNRTI in first-line treatment regimen for HIV treatment, particularly in resource limited settings.

  12. Clinical Use of Infliximab Trough Levels and Antibodies to Infliximab in Pediatric Patients With Inflammatory Bowel Disease.

    Science.gov (United States)

    Merras-Salmio, Laura; Kolho, Kaija-Leena

    2017-02-01

    Optimizing infliximab (IFX) treatment in pediatric patients with inflammatory bowel disease (IBD) by using serum infliximab (S-IFX) trough levels and antibodies to IFX is recommended. There is need for studies assessing this strategy in clinical practice. We retrospectively identified all pediatric patients with IBD (n = 146, median age 14.8 years) treated with IFX at our tertiary referral center from 2003 to 2014. All were analyzed for IFX trough levels (S-IFX, n = 475), and IFX antibody (IFX-Ab, n = 219) titers were included. Both were analyzed using enzyme-linked immunosorbent assay. We correlated these parameters with concurrently analyzed fecal calprotectin levels and the treatment outcome. If IFX had no efficacy, or a loss of response occurred, 40 of 64 (63%) had trough levels <2.0 mg/L, with negative IFX-Ab in 37 of 59 (63%). If the S-IFX was very low (<0.2 mg/L), 4 of 36 still had negative IFX-Ab. Concurrent azathioprine therapy did not relate to IFX-Ab. Fecal calprotectin was significantly lower in patients with clinical remission or ongoing therapy compared with those with subsequent loss of efficacy: medians 95 μg/g (33-308) and 670 μg/g (264-1473), P < 0.0001. The S-IFX median was substantially higher in patients with either remission or ongoing therapy, compared with those with no or loss of efficacy: 3.7 mg/L (1.8-5.4) and 1.2 mg/L (0.03-4.4, P = 0.01), respectively. Measuring IFX trough levels and fecal calprotectin has a potential impact on the treatment strategies and should be included in clinical routine. Low IFX trough levels associate with increased antibodies to IFX in most, but not in all cases.

  13. Genotypic evaluation of etravirine sensitivity of clinical human immunodeficiency virus type 1 (HIV-1) isolates carrying resistance mutations to nevirapine and efavirenz.

    Science.gov (United States)

    Oumar, A A; Jnaoui, K; Kabamba-Mukadi, B; Yombi, J C; Vandercam, B; Goubau, P; Ruelle, J

    2010-01-01

    Etravirine is a second-generation non-nucleoside reverse transcriptase inhibitor (NNRTI) with a pattern of resistance mutations quite distinct from the current NNRTIs. We collected all routine samples of HIV-1 patients followed in the AIDS reference laboratory of UCLouvain (in 2006 and 2007) carrying resistance-associated mutations to nevirapine (NVP) or efavirenz (EFV). The sensitivity to Etravirine was estimated using three different drug resistance algorithms: ANRS (July 2008), IAS (December 2008) and Stanford (November 2008). We also verified whether the mutations described as resistance mutations are not due to virus polymorphisms by the study of 58 genotypes of NNRTI-naive patients. Sixty one samples harboured resistance to NVP and EFV: 41/61 had at least one resistance mutation to Etravirine according to ANRS-IAS algorithms; 42/61 samples had at least one resistance mutation to Etravirine according to the Stanford algorithm. 48 and 53 cases were fully sensitive to Etravirine according to ANRS-IAS and Stanford algorithms, respectively. Three cases harboured more than three mutations and presented a pattern of high-degree resistance to Etravirine according to ANRS-IAS algorithm, while one case harboured more than three mutations and presented high degree resistance to Etravirine according to the Stanford algorithm. The V1061 and V179D mutations were more frequent in the ARV-naive group than in the NNRTI-experienced one. According to the currently available algorithms, Etravirine can still be used in the majority of patients with virus showing resistance to NVP and/or EFV, if a combination of other active drugs is included.

  14. Absorber Alignment Measurement Tool for Solar Parabolic Trough Collectors: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Stynes, J. K.; Ihas, B.

    2012-04-01

    As we pursue efforts to lower the capital and installation costs of parabolic trough solar collectors, it is essential to maintain high optical performance. While there are many optical tools available to measure the reflector slope errors of parabolic trough solar collectors, there are few tools to measure the absorber alignment. A new method is presented here to measure the absorber alignment in two dimensions to within 0.5 cm. The absorber alignment is measured using a digital camera and four photogrammetric targets. Physical contact with the receiver absorber or glass is not necessary. The alignment of the absorber is measured along its full length so that sagging of the absorber can be quantified with this technique. The resulting absorber alignment measurement provides critical information required to accurately determine the intercept factor of a collector.

  15. Chronic administration of the antiretroviral nevirapine increases body weight, food, and water intake in albino Wistar rats.

    Science.gov (United States)

    Umoren, Elizabeth Bassey; Obembe, Agona Odeh; Osim, Eme Effiom

    2012-01-01

    Nevirapine (NVP) is an antiretroviral medication that prevents human immunodeficiency virus (HIV) cells from multiplying in the blood. This study was undertaken to investigate the effect of chronic administration of NVP on body weight, food, and water intake using apparently healthy albino Wistar rats. Twenty adult albino Wistar rats (50-125 g body weight) were used for the study. Rats in the control group (n=10) were fed normal rodent chow, whereas the NVP group (n=10) were fed by gavage NVP (0.4 mg/kg body weight) two times daily (07.00 h and 18.00 h) in addition to normal rodent chow for 12 weeks. All animals were allowed free access to clean drinking water. Results showed that the mean daily food and water intake in the NVP group were significantly higher (pbody weight in the NVP group was significantly higher (pbody weight in rats, probably due to its stimulatory effects on food and water intake.

  16. Shared peptide binding of HLA Class I and II alleles associate with cutaneous nevirapine hypersensitivity and identify novel risk alleles

    DEFF Research Database (Denmark)

    Pavlos, Rebecca; McKinnon, Elizabeth J.; Ostrov, David A.

    2017-01-01

    specificities and binding pocket structure. We demonstrate that primary predisposition to cutaneous NVP HSR, seen across ancestral groups, can be attributed to a cluster of HLA-C alleles sharing a common binding groove F pocket with HLA-C*04:01. An independent association with a group of class II alleles which......Genes of the human leukocyte antigen (HLA) system encode cell-surface proteins involved in regulation of immune responses, and the way drugs interact with the HLA peptide binding groove is important in the immunopathogenesis of T-cell mediated drug hypersensitivity syndromes. Nevirapine (NVP......), is an HIV-1 antiretroviral with treatment-limiting hypersensitivity reactions (HSRs) associated with multiple class I and II HLA alleles. Here we utilize a novel analytical approach to explore these multi-allelic associations by systematically examining HLA molecules for similarities in peptide binding...

  17. Effectiveness of a Treatment Switch to Nevirapine plus Tenofovir and Emtricitabine (or Lamivudine) in Adults with HIV-1 Suppressed Viremia

    DEFF Research Database (Denmark)

    Llibre, Josep M; Bravo, Isabel; Ornelas, Arelly

    2015-01-01

    follow-up 23 (6.7%) individuals (17 on lamivudine, 6 on emtricitabine; p = 0.034) developed VF and treatment modification due to toxicity occurred in 36 (10.7%). Factors independently associated with VF in a multivariate analysis were: intravenous drug use (HR 1.51; 95%CI 1.12, 2.04), time......BACKGROUND: Switching subjects with persistently undetectable HIV-1 viremia under antiretroviral treatment (ART) to once-daily tenofovir/emtricitabine (or lamivudine) + nevirapine is a cost-effective and well-tolerated strategy. However, the effectiveness of this approach has not been established...... equalled failure. The main endpoint was plasma HIV-RNA HIV-1 RNA treatment due to toxicity. During the whole...

  18. Frictional Behavior of Altered Basement Approaching the Nankai Trough

    Science.gov (United States)

    Saffer, D. M.; Ikari, M.; Rooney, T. O.; Marone, C.

    2017-12-01

    The frictional behavior of basement rocks plays an important role in subduction zone faulting and seismicity. This includes earthquakes seaward of the trench, large megathrust earthquakes where seamounts are subducting, or where the plate interface steps down to basement. In exhumed subduction zone rocks such as the Shimanto complex in Japan, slivers of basalt are entrained in mélange which is evidence of basement involvement in the fault system. Scientific drilling during the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) recovered basement rock from two reference sites (C0011 and C0012) located seaward of the trench offshore the Kii Peninsula during Integrated Ocean Discovery Program (IODP) Expeditions 322 and 333. The basement rocks are pillow basalts that appear to be heterogeneously altered, resulting in contrasting dense blue material and more vesicular gray material. Major element geochemistry shows differences in silica, calcium oxides and loss-on-ignition between the two types of samples. Minor element geochemistry reveals significant differences in vanadium, chromium, and barium. X-ray diffraction on a bulk sample powder representing an average composition shows a phyllosilicate content of 20%, most of which is expandable clays. We performed laboratory friction experiments in a biaxial testing apparatus as either intact sample blocks, or as gouge powders. We combine these experiments with measurements of Pennsylvania slate for comparison, including a mixed-lithology intact block experiment. Intact Nankai basement blocks exhibit a coefficient of sliding friction of 0.73; for Nankai basement powder, slate powder, slate blocks and slate-on-basement blocks the coefficient of sliding friction ranges from 0.44 to 0.57. At slip rates ranging from 3x10-8 to 3x10-4 m/s we observe predominantly velocity-strengthening frictional behavior, indicating a tendency for stable slip. At rates of < 1x10-6 m/s some velocity-weakening was observed, specifically in

  19. Modular Trough Power Plant Cycle and Systems Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Price, H.; Hassani, V.

    2002-01-01

    This report summarizes an analysis to reduce the cost of power production from modular concentrating solar power plants through a relatively new and exciting concept that merges two mature technologies to produce distributed modular electric power in the range of 500 to 1,500 kWe. These are the organic Rankine cycle (ORC) power plant and the concentrating solar parabolic (CSP) trough technologies that have been developed independent of each other over many years.

  20. Grounding zone wedges, Kveithola Trough (NW Barents Sea)

    Science.gov (United States)

    Rebesco, Michele; Urgeles, Roger; Özmaral, Asli; Hanebuth, Till; Caburlotto, Andrea; Hörner, Tanja; Lantzsch, Hendrik; LLopart, Juame; Lucchi, Renata; Skøtt Nicolaisen, Line; Giacomo, Osti; Sabbatini, Anna; Camerlenghi, Angelo

    2014-05-01

    Swath bathymetry within Kveithola Trough (NW Barents Sea) shows a seafloor characterized by E-W trending megascale glacial lineations (MSGLs) overprinted by transverse Grounding Zone Wedges (GZWs), which give the trough a stair profile (Rebesco et al., 2011). GZWs are formed by deposition of subglacial till at temporarily stable ice-stream fronts in between successive episodic retreats (Rüther et al., 2012; Bjarnadóttir et al., 2012). Sub-bottom data show that present-day morphology is largely inherited from palaeo-seafloor topography of GZWs, which is draped by a deglacial to early Holocene glaciomarine sediments (about 15 m thick). The ice stream that produced such subglacial morphology was flowing from East to West inside Kveithola Trough during Last Glacial Maximum. Its rapid retreat was likely associated with progressive lift-offs, and successive rapid melting of the grounded ice, induced by the eustatic sea-level rise (Lucchi et al., 2013). References: Bjarnadóttir, L.R., Rüther, D.C., Winsborrow, M.C.M., Andreassen, K., 2012. Grounding-line dynamics during the last deglaciation of Kveithola, W Barents Sea, as revealed by seabed geomorphology and shallow seismic stratigraphy. Boreas, 42, 84-107. Lucchi R.G., et al. 2013. Postglacial sedimentary processes on the Storfjorden and Kveithola TMFs: impact of extreme glacimarine sedimentation. Global and Planetary Change, 111, 309-326. Rebesco, M., et al. 2011. Deglaciation of the Barents Sea Ice Sheet - a swath bathymetric and subbottom seismic study from the Kveitehola Trough. Marine Geology, 279, 141-14. Rüther, D.C., Bjarnadóttir, L.R., Junttila, J., Husum, K., Rasmussen, T.L., Lucchi, R.G., Andreassen, K., 2012. Pattern and timing of the north-western Barents Sea Ice Sheet deglaciation and indications of episodic Holocene deposition. Boreas 41, 494-512.

  1. Towards to Resilience Science -Research on the Nankai trough seismogenic zone-

    Science.gov (United States)

    Kaneda, Yoshiyuki; Shiraki, Wataru; Fujisawa, Kazuhito; Tokozakura, Eiji

    2017-04-01

    For the last few decades, many destructive earthquakes and tsunamis occurred in the world. Based on lessons learnt from 2004 Sumatra Earthquake/Tsunamis, 2010 Chilean Earthquake/Tsunami and 2011 East Japan Earthquake/Tsunami, we recognized the importance of real time monitoring on Earthquakes and Tsunamis for disaster mitigation. Recently, Kumamoto Earthquake occurred in 2006. This destructive Earthquake indicated that multi strong motions including pre shock and main shock generated severe earthquake damages buildings. Furthermore, we recognize recovers/ revivals are very important and difficult. In Tohoku area damaged by large tsunamis, recovers/revivals have been under progressing after over 5 years passed after the 2011 Tohoku Earthquake. Therefore, we have to prepare the pre plan before next destructive disasters such as the Nankai trough mega thrust earthquake. As one of disaster countermeasures, we would like to propose that Disaster Mitigation Science. This disaster mitigation science is including engineering, science, medicine and social science such as sociology, informatics, law, literature, art, psychology etc. For Urgent evacuations, there are some kinds of real time monitoring system such as Dart buoy and ocean floor network. Especially, the real time monitoring system using multi kinds of sensors such as the accelerometer, broadband seismometer, pressure gauge, difference pressure gauge, hydrophone and thermometer is indispensable for Earthquakes/ Tsunamis monitoring. Furthermore, using multi kind of sensors, we can analyze and estimate broadband crustal activities around mega thrust earthquake seismogenic zones. Therefore, we deployed DONET1 and DONET2 which are dense ocean floor networks around the Nankai trough Southwestern Japan. We will explain about Resilience Science and real time monitoring systems around the Nankai trough seismogenic zone.

  2. Seafloor Crustal Deformation Close to the Nankai Trough, Japan

    Science.gov (United States)

    Tadokoro, K.; Sugimoto, S.; Watanabe, T.; Okuda, T.; Muto, D.; Kimoto, A.; Ando, M.; Sayanagi, K.; Kuno, M.

    2007-12-01

    \\ \\ \\ The Nankai Trough is one of the active plate boundaries in the world. Major subduction earthquakes, Nankai and Tonankai earthquakes, repeatedly occur with intervals of 100-150 years at the Nankai Trough. The last large earthquakes occurred in 1944 and 1946. Therefore, the 50-years probabilities of next major earthquakes are 80- 90 %. It is necessary to monitor crustal deformation above the source regions for the sake of earthquake prediction and disaster prevention. The source regions of the earthquakes are located beneath the sea bottom, to the south of the Japan Islands. \\ \\ \\ One of the useful tools to monitor seafloor crustal deformation is the observation system composed of the acoustic ranging and kinematic GPS positioning techniques. We have installed seafloor benchmarks for acoustic ranging at the Nankai Trough region. We repeatedly observed at the two sites from 2004. The result of the repeated observation shows that the repeatability of the measurement is +/- 2-3 cm for the horizontal components. Also we detect crustal deformation related to plate convergence using our system. The velocity vectors derived from our repeated observation are (7.0 cm/yr, N78W) and (5.2 cm/yr, N87W), which is consistent to the on-land continuous observations. \\ \\ \\ This study is promoted by Ministry of Education, Culture, Sports, Science and Technology, Japan. We are grateful to the captains and crews of Research Vessels, "Asama"and "Hokuto."

  3. Identifying the "Foot of the Continental Slope" of high-latitude continental margins influenced by trough mouth fans

    Science.gov (United States)

    Sverre Laberg, Jan

    2017-04-01

    The continental slope of high-latitude margins often include trough mouth fans, which are sediment fans situated in front of large troughs crossing the continental shelf. The troughs acted as corridors for paleo-ice streams, sectors of fast-flowing ice within the large ice sheets of the last glacial maximum as well as previous glacials. The paleo-ice streams were highly efficient erosional agents, eroding and transporting large volumes of sediments to the continental shelf edge. Here, these sediments were released to move downslope as large debris flows, the "building blocks" of these fans. Due to the very large sediment volume included within these fans, they represent prominent depocenters forming low-gradient sectors (axial gradient often being as low as 1 degree or less) with no clear morphological distinction of the continental slope including its lower limit. Under the UN Convention on the Law of the Sea, the criteria provided in Article 76 includes the lower limit or "foot" of the continental slope as one important parameter in the extended Continental Shelf delineation (i.e. beyond the 200 M exclusive economic zone). Because of this, the Norwegian submission regarding the outer limits of the continental shelf in the Norwegian Sea and the Arctic Ocean argued that the origin of the sub-sea floor sediments on the slope needed to be considered when identifying the location of the foot of the continental slope. This was done by mapping the outer limits of the large debris flow deposits of the trough mouth fans, deposits that without doubt have their origin from the continental shelf. Thus, in these cases, the foot of the continental slope coincide with the downslope termination of the large debris flow deposits and the outer limit of the continental shelf lies 60 M beyond this point. The data used for mapping includes swath bathymetry, sub-bottom profiles and short sediment samples (< 10 m), and we present and discuss examples from the Bear Island Trough Mouth

  4. A376S in the connection subdomain of HIV-1 reverse transcriptase confers increased risk of virological failure to nevirapine therapy

    DEFF Research Database (Denmark)

    Paredes, Roger; Puertas, Maria Carmen; Bannister, Wendy

    2011-01-01

    Background. The clinical relevance of mutations in the connection subdomain and the ribonuclease (RNase) H domain of HIV-1 reverse transcriptase (RT) is uncertain. Methods. The risk of virological failure to nonnucleoside RT inhibitor (NNRTI)-based antiretroviral therapy (ART) was evaluated...... in NNRTI-naive patients who started NNRTIs in the EuroSIDA study after July 1997 according to preexisting substitutions in the connection subdomain and the RNase H domain of HIV-1 RT. An observed association between A376S and virological failure was further investigated by testing in vitro NNRTI...... = .013). A376S conferred selective low-level nevirapine resistance in vitro, and led to greater affinity for double-stranded DNA. Conclusions. The A376S substitution in the connection subdomain of HIV-1 RT causes selective nevirapine resistance and confers an increased risk of virological failure...

  5. A randomized trial comparing initial HAART regimens of nelfinavir/nevirapine and ritonavir/saquinavir in combination with two nucleoside reverse transcriptase inhibitors

    DEFF Research Database (Denmark)

    Kirk, Ole; Lundgren, Jens D; Pedersen, Court

    2003-01-01

    BACKGROUND: A triple-class HAART regimen may be associated with a better virological effect than conventional regimens, but may also lead to toxicity and more profound resistance. METHODS: Randomized, controlled, open-label trial of 233 protease inhibitor- and non-nucleoside reverse transcriptase...... inhibitor-naive HIV-infected patients allocated to a regimen of nelfinavir and nevirapine (1250/200 mg twice daily; n = 118) or ritonavir and saquinavir (400/400 mg twice daily; n = 115), both in combination with two nucleoside reverse transcriptase inhibitors. The primary end-point was HIV RNA ....037. CONCLUSION: A regimen of nelfinavir/nevirapine had a favourable virological effect and tolerability over a 48-week period compared with ritonavir/saquinavir, when administered in combination with two nucleoside reverse transcriptase inhibitors. However, more extensive follow-up is required to determine...

  6. COMPARATIVE STUDY OF EFFICACY OF TWO ANTIRETROVIRAL REGIMENTS (ZIDOUVDINE+LAMIVUDINE+NEVIRAPHINE VS STAVUDINE+LAMIVUDINE+NEVIRAPINE IN HIV/AIDS PATIENTS

    Directory of Open Access Journals (Sweden)

    Mopuri Muneer Kanha

    2015-02-01

    Full Text Available BACKGROUND: AIDS, the acquired immunodeficiency syndrome, is the worst disease in the history of medicine due to HIV infection in many sexually active people. This disease is treated with two regimens of drugs in the ART centers at free of cost by the government. AIMS AND OBJECTIVES: To study and compare the efficacy of two antiretroviral regimens (zidovudine +lamivudine+ nevirapine vs ( S tavudine + lamivudine +nevirapine in HIV/AIDS patients. Methods: It is a longitudinal, prospective, observational study, carried at ART centers of siddhartha medical college, Vijayawada, AP and Guntur medical college, Guntur, AP from October 2006 to March 2008. Results: 650 patients were enrolled into study. Out of 650, 325 patients were received Tab.Zidovudine +Tab.Lamivudine+Tab.Nevirapine (Regimen A and 325 patients were received Tab. Stavudine + Tab.Lamivudine + Tab. Nevirapine (Regimen B in fixed drug combination. The study is designed for a Period of 12 months by recording observations at 0 months, 6months and 12months. All the cases enrolled had been studied prospectively at the ART centers and the data entered into the case sheets. The adherence to the ART is assessed by asking the patients to get the empty drug bottles and checking the number of remaining tablets. The chi - square test is applied for all the parameters after 6 months data and after 12 months data with degree of freedom (D f of > 1 = and > P = value as 0.05 (p=0.05 and the level of significance as x 2 >3.84. CONCLUSIONS: Stavudine containing regimen B is having better efficacy than zidovudine containing regimen A

  7. Prevention of perinatal HIV I transmission by protease inhibitor based triple drug antiretroviral therapy versus nevirapine as single dose at the time of delivery.

    Science.gov (United States)

    Bendle, Meenakshi; Bajpai, Smrati; Choudhary, Ashwini; Pazare, Amar

    2012-12-01

    In India, parent to child transmission is the most important source of HIV infection in children below fifteen years of age. Transmission of HIV from mother to child can occur even at low or undetectable HIV virus levels. CD4 count or HIV RNA levels should not be the determining factor when deciding whether to use antiretroviral drugs for prevention of perinatal transmission of HIV. Use of single dose nevirapine during labour, in prevention of parent to child transmission (PPTCT) programme for pregnant females with CD4 count > 250 cells/cumm has less efficacy in reducing perinatal transmission. And there are high chances of development of nevirapine resistance to both mother and baby after single dose nevirapine exposure. Short course Protease inhibitor(PI) based triple drug combination ART from 28 weeks till delivery for perinatal prophylaxis is effective in reducing perinatal HIV transmission. PI's are safe in pregnancy and also have less chances of development of resistance when used for perinatal prophylaxis and stopped post delivery.Hence, it is opined that PI based combination ART should be offered to pregnant females in PPTCT programme, thereby preventing occurrence of paediatric HIV infection in India. This can have significant impact on the society at large.

  8. On purpose simulation model for molten salt CSP parabolic trough

    Science.gov (United States)

    Caranese, Carlo; Matino, Francesca; Maccari, Augusto

    2017-06-01

    The utilization of computer codes and simulation software is one of the fundamental aspects for the development of any kind of technology and, in particular, in CSP sector for researchers, energy institutions, EPC and others stakeholders. In that extent, several models for the simulation of CSP plant have been developed with different main objectives (dynamic simulation, productivity analysis, techno economic optimization, etc.), each of which has shown its own validity and suitability. Some of those models have been designed to study several plant configurations taking into account different CSP plant technologies (Parabolic trough, Linear Fresnel, Solar Tower or Dish) and different settings for the heat transfer fluid, the thermal storage systems and for the overall plant operating logic. Due to a lack of direct experience of Molten Salt Parabolic Trough (MSPT) commercial plant operation, most of the simulation tools do not foresee a suitable management of the thermal energy storage logic and of the solar field freeze protection system, but follow standard schemes. ASSALT, Ase Software for SALT csp plants, has been developed to improve MSPT plant's simulations, by exploiting the most correct operational strategies in order to provide more accurate technical and economical results. In particular, ASSALT applies MSPT specific control logics for the electric energy production and delivery strategy as well as the operation modes of the Solar Field in off-normal sunshine condition. With this approach, the estimated plant efficiency is increased and the electricity consumptions required for the plant operation and management is drastically reduced. Here we present a first comparative study on a real case 55 MWe Molten Salt Parabolic Trough CSP plant placed in the Tibetan highlands, using ASSALT and SAM (System Advisor Model), which is a commercially available simulation tool.

  9. Shifting sources and transport paths for the late Quaternary Escanaba Trough sediment fill (northeast Pacific)

    Science.gov (United States)

    Zuffa, G.G.; De Rosa, R.; Normark, W.R.

    1997-01-01

    Escanaba Trough, which forms the southernmost part of the axial valley of the actively spreading Gorda Ridge, is filled with several hundred meters of sediment of presumed late Quaternary age. Surficial sediment samples from gravity cores, deeper samples (as much as 390 m) from Site 35 of the Deep Sea Drilling Program (Leg 5), and the acoustic character of the sediment fill observed on seismic-reflection profiles indicate that much of the sediment fill is of turbidite origin. Gross composition and heavy- mineral analyses of sand samples show that two distinct petrofacies comprise the sediment fill. The lower part of the fill was derived primarily from the Klamath River source of northern California while the younger fill, including the surficial sand beds, are from the Columbia River drainage much farther north. The Escanaba Trough sediment provides an opportunity to evaluate concepts for paleogeographic and paleotectonic reconstructions that are based on facies analysis and compositional and textural data for the volcanic components because both intrabasinal and extrabasinal sources are present as well as coeval (neovolcanic) and non coeval (paleovolcanic) sourcre This study of a modern basin shows, that although the sediment sources could be identified, it was useful to have some knowledge of the sediment pathway(s), the effects of diagenesis, and the possible effects of sediment sorting as a result of long transport distances from the source area for some components. Application of these same techniques to ancient deposits without benefit of the additional parameters will face limitations.

  10. Measurement of Hydrogen Purge Rates in Parabolic Trough Receiver Tubes: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Glatzmaier, G. C.

    2010-10-01

    The purpose of this research is to investigate and develop methods to remove hydrogen centrally from commercial parabolic trough power plants. A mathematical model was developed that tracks the generation and transport of hydrogen within an operating plant. Modeling results predicted the steady-state partial pressure of hydrogen within the receiver annuli to be ~1 torr. This result agrees with measured values for the hydrogen partial pressure. The model also predicted the rate at which hydrogen must be actively removed from the expansion tank to reduce the partial pressure of hydrogen within the receiver annuli to less than 0.001 torr. Based on these results, mitigation strategies implemented at operating parabolic trough power plants can reduce hydrogen partial pressure to acceptable levels. Transient modeling predicted the time required to reduce the hydrogen partial pressures within receiver annuli to acceptable levels. The times were estimated as a function of bellows temperature, getter quantity, and getter temperature. This work also includes an experimental effort that will determine the time required to purge hydrogen from a receiver annulus with no getter.

  11. High H2O/Ce of K-rich MORB from Lena Trough and Gakkel Ridge, Arctic Ocean

    Science.gov (United States)

    Snow, J. E.; Feig, S. T.

    2014-12-01

    Lena Trough in the Arctic ocean is the oblique spreading continuation of Gakkel Ridge through the Fram Strait (eg Snow et al. 2011). Extreme trace element and isotopic compositions seen in Lena Trough basalt appear to be the enriched end member dominating the geochemistry of the Western Volcanic Zone of the Western Gakkel Ridge as traced by Pb isotopes, K2O/TiO2, Ba/Nb and other isotopic, major and trace element indicators of mixing (Nauret et al., 2011). This is in contrast to neighboring Gakkel Ridge which has been spreading for 50-60 million years. Basalts from Lena Trough also show a pure MORB noble gas signature (Nauret et al., 2010) and peridotites show no evidence of ancient components in their Os isotopes (Lassiter, et al., in press). The major and trace element compositions of the basalts, however are very distinct from MORB, being far more potassic than all but a single locality on the SW Indian Ridge. We determined H2O and trace element composiitions of a suite of 17 basalt glasses from the Central Lena Trough (CLT) and the Gakkel Western Volcanic Zone, including many of those previously analyzed by Nauret et al. (2012). The Western Gakkel glasses have high H2O/Ce for MORB (>300) suggesting a water rich source consistent with the idea that the northernmost Atlantic mantle is enriched in water (Michael et al., 1995). They are within the range of Eastern Gakkel host glasses determined by Wanless et al, 2013. The Lena Trough (CLT) glasses are very rich in water for MORB (>1% H2O) and are among the highest H2O/Ce (>400) ever measured in MORB aside from melt inclusions in olivine. Mantle melting dynamics and melt evolution cannot account for the H2O/Ce variations in MORB, as these elements have similar behavior during melting and crustal evolution. Interestingly, the H2O/K2O ratios in the basalts are only around 1. This is because the K2O levels in the CLT glasses are very high as well relative to REE. The absolutely linear relationship between H2O and K2O

  12. Loading regimen required to rapidly achieve therapeutic trough plasma concentration of teicoplanin and evaluation of clinical features

    Directory of Open Access Journals (Sweden)

    Seki M

    2012-11-01

    Full Text Available Masafumi Seki,1,* Kaori Yabuno,1,2,* Koji Miyawaki,1,2 Yoshihiro Miwa,2 Kazunori Tomono11Division of Infection Control and Prevention, 2Department of Pharmacy, Osaka University Hospital, Suita, Osaka, Japan*These authors contributed equally to this workBackground: A trough concentration of >20 mg/L is considered the optimal dosage of teicoplanin required to ensure early therapeutic effects against methicillin-resistant Staphylococcus aureus (MRSA infections including those in patients who develop febrile neutropenia after chemotherapy. This study determines appropriate initial doses during the first 2 days of administration and evaluates the therapeutic target teicoplanin trough concentration.Method: A 2-day regimen was evaluated in patients treated with 600 mg and 1200 mg or 1200 mg and 600 mg (total 1800 mg, Group 1, 800 mg and 800 mg (total 1600 mg, Group 2, and 800 mg and 400 mg (total 1200 mg, Group 3 of teicoplanin on Days 1 and 2, respectively. We also compared the efficiency and adverse effects at trough concentrations of 15–20 mg/L (Group A, n = 28 with >20 mg/L (Group B, n = 27 of teicoplanin, and also compared them with those on the similar concentrations of vancomycin (Groups C and D, n = 50 and 34, respectively.Results: The mean trough concentrations of teicoplanin on Days 4 or 5 were 22.2, 17.5, and 16.2 mg/L in Groups 1, 2, and 3, respectively. The clinical efficiency was 85.7%, 81.5%, 92.0%, and 91.5%, in Groups A, B, C, and D, respectively. The rates of adverse effects were not high in teicoplanin (nephrotoxicity, 7.1% and 3.7%, and hepatotoxicity, 14.3% and 11.1% in Groups A and B, respectively. However, more adverse effects tended to arise in patients who received vancomycin in nephrotoxicity (14.0% and 11.8%, in Groups C and D, respectively.Conclusion: These results suggest that the 2-day regimens with total 1800 mg achieved the most effective therapeutic trough plasma concentration of teicoplanin (20 mg/L. However, 15–20

  13. The F-region trough: seasonal morphology and relation to interplanetary magnetic field

    Directory of Open Access Journals (Sweden)

    M. Voiculescu

    2006-03-01

    Full Text Available We present here the results of a statistical study of the ionospheric trough observed in 2003 by means of satellite tomography. We focus on the seasonal morphology of the trough occurrence and investigate the trough latitude, width and the horizontal gradients at the edges, at different magnetic local times, as well as their relations to geomagnetic activity and the interplanetary magnetic field. A seasonal effect is noticed in the diurnal variation of the trough latitude, indicating that summer clearly differs from the other seasons. In winter the troughs seem to follow the solar terminator. The width of the trough has a diurnal variation and it depends on the season, as well. The broadest troughs are observed in winter and the narrowest ones in summer. A discontinuity in the diurnal variation of the trough latitude is observed before noon. It is suggested that this is an indication of a difference between the generation mechanisms of morningside and eveningside troughs. The density gradients at the edges have a complex dependence on the latitude of the trough and on geomagnetic activity. The photoionization and the auroral precipitation are competing in the formation of the trough walls at different magnetic local times. An important finding is that the interplanetary magnetic field plays a role in the occurrence of the trough at different levels of geomagnetic activity. This is probably associated with the topology of the polar cap convection pattern, which depends on the directions of the IMF components By and Bz.

  14. Pregnancy rates in HIV-positive women using contraceptives and efavirenz-based or nevirapine-based antiretroviral therapy in Kenya: a retrospective cohort study.

    Science.gov (United States)

    Patel, Rena C; Onono, Maricianah; Gandhi, Monica; Blat, Cinthia; Hagey, Jill; Shade, Starley B; Vittinghoff, Eric; Bukusi, Elizabeth A; Newmann, Sara J; Cohen, Craig R

    2015-11-01

    Concerns have been raised about efavirenz reducing the effectiveness of contraceptive implants. We aimed to establish whether pregnancy rates differ between HIV-positive women who use various contraceptive methods and either efavirenz-based or nevirapine-based antiretroviral therapy (ART) regimens. We did this retrospective cohort study of HIV-positive women aged 15-45 years enrolled in 19 HIV care facilities supported by Family AIDS Care and Education Services in western Kenya between Jan 1, 2011, and Dec 31, 2013. Our primary outcome was incident pregnancy diagnosed clinically. The primary exposure was a combination of contraceptive method and efavirenz-based or nevirapine-based ART regimen. We used Poisson models, adjusting for repeated measures, and demographic, behavioural, and clinical factors, to compare pregnancy rates among women receiving different contraceptive and ART combinations. 24,560 women contributed 37,635 years of follow-up with 3337 incident pregnancies. In women using implants, adjusted pregnancy incidence was 1.1 per 100 person-years (95% CI 0.72-1.5) for nevirapine-based ART users and 3.3 per 100 person-years (1.8-4.8) for efavirenz-based ART users (adjusted incidence rate ratio [IRR] 3.0, 95% CI 1.3-4.6). In women using depot medroxyprogesterone acetate, adjusted pregnancy incidence was 4.5 per 100 person-years (95% CI 3.7-5.2) for nevirapine-based ART users and 5.4 per 100 person-years (4.0-6.8) for efavirenz-based ART users (adjusted IRR 1.2, 95% CI 0.91-1.5). Women using other contraceptive methods, except for intrauterine devices and permanent methods, had 3.1-4.1 higher rates of pregnancy than did those using implants, with 1.6-2.8 higher rates in women using efavirenz-based ART. Although HIV-positive women using implants and efavirenz-based ART had a three-times higher risk of contraceptive failure than did those using nevirapine-based ART, these women still had lower contraceptive failure rates than did those receiving all other

  15. A trough for improved SFG spectroscopy of lipid monolayers

    Science.gov (United States)

    Franz, Johannes; van Zadel, Marc-Jan; Weidner, Tobias

    2017-05-01

    Lipid monolayers are indispensable model systems for biological membranes. The main advantage over bilayer model systems is that the surface pressure within the layer can be directly and reliably controlled. The sensitive interplay between surface pressure and temperature determines the molecular order within a model membrane and consequently determines the membrane phase behavior. The lipid phase is of crucial importance for a range of membrane functions such as protein interactions and membrane permeability. A very reliable method to probe the structure of lipid monolayers is sum frequency generation (SFG) vibrational spectroscopy. Not only is SFG extremely surface sensitive but it can also directly access critical parameters such as lipid order and orientation, and it can provide valuable information about protein interactions along with interfacial hydration. However, recent studies have shown that temperature gradients caused by high power laser beams perturb the lipid layers and potentially obscure the spectroscopic results. Here we demonstrate how the local heating problem can be effectively reduced by spatially distributing the laser pulses on the sample surface using a translating Langmuir trough for SFG experiments at lipid monolayers. The efficiency of the trough is illustrated by the detection of enhanced molecular order due to reduced heat load.

  16. Exergetic analysis of parabolic trough solar thermal power plants

    Science.gov (United States)

    Petrakopoulou, F.; Ruperez, B.; San Miguel, G.

    2014-12-01

    A very important component to achieve sustainable development in the energy sector is the improvement of energy efficiency of widely applied thermodynamic processes. Evaluation and optimization methods of energy processes play a crucial role in fulfilling this goal. A suitable method for the evaluation and optimization of energy conversion systems has been proven to be the exergetic analysis. In this work, two parabolic trough solar thermal power plants are simulated in detail using commercial software, and they are further analysed and compared using an exergetic analysis. The first plant uses a thermal fluid to produce the steam required in a steam generator, while the second one produces the steam directly in the solar field. The analysis involves the evaluation of the individual components of the power plants, as well as the performance evaluation of the overall structures. The main goal is to detect thermodynamic inefficiencies of the two different configurations and propose measures to minimize those. We find that the two examined plants have similar main sources of exergy destruction: the solar field (parabolic trough solar collectors), followed by the steam generator. This reveals the importance of an optimal design of these particular components, which could reduce inefficiencies present in the system. The differences in the exergy destruction and exergetic efficiencies of individual components of the two plants are analyzed in detail based on comparable operational conditions.

  17. Thermal and optical efficiency investigation of a parabolic trough collector

    Directory of Open Access Journals (Sweden)

    C. Tzivanidis

    2015-09-01

    Full Text Available Solar energy utilization is a promising Renewable Energy source for covering a variety of energy needs of our society. This study presents the most well-known solar concentrating system, the parabolic trough collector, which is operating efficiently in high temperatures. The simulation tool of this analysis is the commercial software Solidworks which simulates complicated problems with an easy way using the finite elements method. A small parabolic trough collector model is designed and simulated for different operating conditions. The goal of this study is to predict the efficiency of this model and to analyze the heat transfer phenomena that take place. The efficiency curve is compared to a one dimensional numerical model in order to make a simple validation. Moreover, the temperature distribution in the absorber and inside the tube is presented while the heat flux distribution in the outer surface of the absorber is given. The heat convection coefficient inside the tube is calculated and compared with the theoretical one according to the literature. Also the angle efficiency modifier is calculated in order to predict the thermal and optical efficiency for different operating conditions. The final results show that the PTC model performs efficiently and all the calculations are validated.

  18. Parabolic Trough Reference Plant for Cost Modeling with the Solar Advisor Model (SAM)

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, C.

    2010-07-01

    This report describes a component-based cost model developed for parabolic trough solar power plants. The cost model was developed by the National Renewable Energy Laboratory (NREL), assisted by WorleyParsons Group Inc., for use with NREL's Solar Advisor Model (SAM). This report includes an overview and explanation of the model, two summary contract reports from WorleyParsons, and an Excel spreadsheet for use with SAM. The cost study uses a reference plant with a 100-MWe capacity and six hours of thermal energy storage. Wet-cooling and dry-cooling configurations are considered. The spreadsheet includes capital and operating cost by component to allow users to estimate the impact of changes in component costs.

  19. Core Description and a Preliminarily Sedimentology Study of Site 1202D, Leg 195, in the Southern Okinawa Trough

    Directory of Open Access Journals (Sweden)

    Chi-Yue Huang

    2005-01-01

    Full Text Available ODP Site 1202 of Leg 195 was designed primarily for a high-resolution study of the paleoceanography of the Kuroshio Current in the southern Okinawa Trough off NE Taiwan. Four holes were drilled in which Hole 1202D is described in detail in this study for an assessment of core quality for paleoceanography study and understanding of sedimentological features, especially turbidite sedimentation and the sediment provenances during the Late Quaternary in the southern Okinawa Trough. Pelagic mud with insignificant silt or sand layers is observed from the core top down to 133 m (mbsf; Marine Isotope Stages 1-3, but the silt-sand layer ratio (SLR: total thickness of silt and sand layers / 1.5 m of core increases gradually from a value of 50 % between 223 and 279 m, followed by decreases to values 250 _ Slate fragments are commonly found in fine-grained turbidite dominant intervals (160 - 280 m, while mica flakes can be observed in the muds throughout the core. The major detrital components were derived primarily from the Miocene slate belt of the pre-collision accretionary prism of the Central Range in northern Taiwan. The occurrence of volcanics could represent submarine volcanic activity in the active-opening Okinawa Trough back-arc basin off NE Taiwan. Shallow-marine fossils including benthic foraminifers, echinoids, bryozoans and mollusks are also found in the fine-grained turbidite dominant intervals. These fossil assemblages could have been deposited in the shallow shelf and then transported to the depositional site along with voluminous terrigenous materials derived from Taiwan, via submarine channels or by slope failures due to frequent earthquakes induced by plate convergence/collision and extension in the southwestern Okinawa Trough off NE Taiwan. It is concluded that the top 133 m of the core is better suited for paleoceanographic reconstruction.

  20. Standing and Travelling Wave Contributions to the Persistent Ridge-Trough Over North America During Winter 2013/14

    Science.gov (United States)

    Watt-Meyer, O.; Kushner, P. J.

    2015-12-01

    The winter season over North America during 2013/14 was dominated by a persistent ridge-trough that brought warm and dry conditions to the southwestern U.S., and markedly cold temperatures to central and eastern North America [Wang et al., 2014; Hartmann, 2015]. In addition, several cold air outbreaks occurred during the winter season, the strongest of which was around 7 January 2014 and led to minimum daily temperature records being set at many weather stations including Atlanta, Austin, Chicago and New York [Screen et al., in press]. This study uses a novel decomposition of wave variability into standing and travelling components [Watt-Meyer and Kushner, 2015] to diagnose the anomalous circulation of the 2013/14 winter season. This spectral decomposition is an improvement on previous methods because it explicitly accounts for the covariance between standing and travelling waves, and because the real-space components of the signal can be easily reconstructed. An index representing the ridge-trough dipole is computed using mid-tropospheric heights and shown to be well correlated with surface temperatures over central and eastern North America. The contributions to this dipole index from standing waves, westward travelling waves, and eastward travelling waves are calculated. The analysis demonstrates that the cold air outbreak of 7 January 2014 was driven by a synoptic wave of record breaking amplitude intensifying a persistent background amplification of the typical ridge-trough structure seen during North American winter.

  1. A Two-Layer Quasi-Geostrophic Model of Summer Trough Formation in the Australian Subtropical Easterlies.

    Science.gov (United States)

    Fandry, C. B.; Leslie, L. M.

    1984-03-01

    C.B. FandryCSIRO Division of Oceanography, G.P.O. Box 1538, Hobart, Tasmania, Australia 7001 L.M. LeslieAustralian Numerical Meteorology Research Centre, G.P.O. Box 5089AA, Melbourne, Victoria, Australia 3001A dominant feature of the low-level easterly wind flow in the Australian subtropics during summer is the trough development that occurs on both the western and eastern sides of the continent. This phenomenon is investigated analytically with a two-level model. A generalized solution is derived from the steady-state quasi-geostrophic equations governing uniform flow over arbitrarily shaped orography. The model solutions indicate that orography acting alone is of only marginal importance in producing the western trough. However, the high east coast orography is of significance in the formation of the eastern trough.Land-sea temperature contrast is parameterized in terms of equivalent orography with localized surface heating being mathematically equivalent to an orographic depression. The solutions including orography and surface heating acting together simulate well the lower layer flow over the Australian subtropics.

  2. Development of Nevirapine Resistance in Children Exposed to the Prevention of Mother-to-Child HIV-1 Transmission Programme in Maputo, Mozambique

    Science.gov (United States)

    Antunes, Francisco; Zindoga, Pereira; Gomes, Perpétua; Augusto, Orvalho; Mahumane, Isabel; Veloso, Luís; Valadas, Emília; Camacho, Ricardo

    2015-01-01

    Background Single-dose nevirapine (sd-NVP) has been the main option for prevention of mother-to-child transmission (PMTCT) of HIV-1 in low-resource settings. However, sd-NVP can induce the selection of HIV-1 resistant mutations in mothers and infants. In Mozambique, there are limited data regarding the profile of NVP resistance associated mutations (RAM) in the context of PMTCT. Objectives To assess the prevalence and the factors associated with NVP RAM among children born to HIV-1 infected mothers enrolled in the PMTCT programme adopted in Mozambique. Methods One hundred and fifty seven children aged 6 to 48 weeks were sequentially included (July 2011 to March 2012) at four centres in Maputo. Genotyping of RAM was performed in samples with HIV-1 RNA≥ 100 copies/μL (Viroseq). Sequencing was performed with ABI 3100 (Applied Biosystems). Logistic regression modelling was undertaken to identify the factors associated with NVP RAM. Results Seventy-nine children had their samples genotyped. Their median age was 7.0 (3–12) months and 92.4% received prophylaxis with sd-NVP at birth plus daily NVP. 35.4% of mothers received antiretrovirals (ARVs) for PMTCT. ARV RAM were detected in 43 (54.4%) of the children. 45.6% of these children had at least one NVP RAM. The most common mutations associated with NVP resistance were K103N (n = 16) and Y181C (n = 15). NVP RAM was significantly associated with mother exposure to PMTCT (crude odds ratio [OR] 30.3, 95% CI 4.93–186.34) and with mother’s CD4 count < 350 cells/mm3 (crude OR 3.08, 95% CI 1.02–9.32). In the multivariable analysis the mother’s exposure to PMTCT was the only variable significantly associated with NVP RAM (adjusted OR 48.65, 95% CI 9.33–253.66). Conclusions We found a high prevalence of NVP RAM among children who were exposed to the drug regimen for PMTCT in Mozambique. The mothers’ exposure to PMTCT significantly increased the risk of NVP RAM. PMID:26161559

  3. Virological failure of staggered and simultaneous treatment interruption in HIV patients who began Efavirenz-based regimens after allergic reactions to nevirapine

    Directory of Open Access Journals (Sweden)

    Siripassorn Krittaecho

    2013-01-01

    Full Text Available Abstract Objective The objective of this work was to study the virological outcomes associated with two different types of treatment interruption strategies in patients with allergic reactions to nevirapine (NVP. We compared the virological outcomes of (1 HIV-1-infected patients who discontinued an initial NVP-based regimen because of cutaneous allergic reactions to NVP; different types of interruption strategies were used, and second-line regimen was based on efavirenz (EFV; and (2 HIV-1-infected patients who began an EFV-based regimen as a first-line therapy (controls. Methods This retrospective cohort included patients who began an EFV-based regimen, between January 2002 and December 2008, as either an initial regimen or as a subsequent regimen after resolving a cutaneous allergic reaction against an initial NVP-based regimen. The study ended in March 2010. The primary outcome was virological failure, which was defined as either (a two consecutive plasma HIV-1 RNA levels >400 copies/mL or (b a plasma HIV-1 RNA level >1,000 copies/mL plus any genotypic resistance mutation. Results A total of 559 patients were stratified into three groups: (a Simultaneous Interruption, in which the subjects simultaneously discontinued all the drugs in an NVP-based regimen following an allergic reaction (n=161; (b Staggered Interruption, in which the subjects discontinued NVP treatment while continuing nucleoside reverse transcriptase inhibitor (NRTI backbone therapy for a median of 7 days (n=82; and (c Control, in which the subjects were naïve to antiretroviral therapy (n=316. The overall median follow-up time was 43 months. Incidence of virological failure in Simultaneous Interruption was 12.9 cases per 1,000 person-years, which trended toward being higher than the incidences in Staggered Interruption (5.4 and Control (6.6. However, differences were not statistically significant. Conclusions Among the patients who had an acute allergic reaction to first

  4. Geomechanical property of gas hydrate sediment in the Nankai trough

    Energy Technology Data Exchange (ETDEWEB)

    Hato, M. [Earth Remote Sensing Data Analysis Center, Tokyo (Japan); Matsuoka, T.; Ikeda, H. [Kyoto Univ., Kyoto (Japan). Dept. of Civil and Earth Resources Engineering; Inamori, T.; Saeki, T. [Japan Oil, Gas and Metals National Corp., Chiba (Japan). Technology Research Center

    2008-07-01

    Well logging data and core samples from the Nankai trough area were used to investigate the geomechanical properties and geological history of gas hydrate-bearing sediments. The Coulomb-Mohr failure criterion was used to calculate the mechanical strength of the hydrate sediments. The dynamic Young's modulus was calculated using theoretical and experimental data. The study showed that sediments below the gas hydrate later are mechanically weaker than sediments within the gas hydrate layer. The mechanical strength of the core samples was then measured both before and after dissociation. The study showed that saturated gas hydrates are 4 times stronger than gas hydrate-dissociated cores. It was concluded that hydrate-bearing sediments are mechanically stronger than non-hydrate-bearing sediments. Results of the study will be used to develop methods of predicting risk factors for sea floor deformations and well-bore collapse during gas hydrate extraction processes in hydrate reservoirs. 6 refs., 5 figs.

  5. Air-borne shape measurement of parabolic trough collector fields

    Science.gov (United States)

    Prahl, Christoph; Röger, Marc; Hilgert, Christoph

    2017-06-01

    The optical and thermal efficiency of parabolic trough collector solar fields is dependent on the performance and assembly accuracy of its components such as the concentrator and absorber. For the purpose of optical inspection/approval, yield analysis, localization of low performing areas, and optimization of the solar field, it is essential to create a complete view of the optical properties of the field. Existing optical measurement tools are based on ground based cameras, facing restriction concerning speed, volume and automation. QFly is an airborne qualification system which provides holistic and accurate information on geometrical, optical, and thermal properties of the entire solar field. It consists of an unmanned aerial vehicle, cameras and related software for flight path planning, data acquisition and evaluation. This article presents recent advances of the QFly measurement system and proposes a methodology on holistic qualification of the complete solar field with minimum impact on plant operation.

  6. Test results, Industrial Solar Technology parabolic trough solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Dudley, V.E. [EG and G MSI, Albuquerque, NM (United States); Evans, L.R.; Matthews, C.W. [Sandia National Labs., Albuquerque, NM (United States)

    1995-11-01

    Sandia National Laboratories and Industrial Solar Technology are cost-sharing development of advanced parabolic trough technology. As part of this effort, several configurations of an IST solar collector were tested to determine the collector efficiency and thermal losses with black chrome and black nickel receiver selective coatings, combined with aluminized film and silver film reflectors, using standard Pyrex{reg_sign} and anti-reflective coated Pyrex{reg_sign} glass receiver envelopes. The development effort has been successful, producing an advanced collector with 77% optical efficiency, using silver-film reflectors, a black nickel receiver coating, and a solgel anti-reflective glass receiver envelope. For each receiver configuration, performance equations were empirically derived relating collector efficiency and thermal losses to the operating temperature. Finally, equations were derived showing collector performance as a function of input insolation value, incident angle, and operating temperature.

  7. A numerical analysis of the energy behavior of a parabolic trough ...

    African Journals Online (AJOL)

    A numerical analysis of the energy behavior of a parabolic trough concentrator. ... Abstract. The solar power is a clean and a durable energy; there are several techniques for using them. When necessary to elevated ... Keywords: Solar energy; parabolic trough concentrator; modelisation; optical efficiency, thermal efficiency ...

  8. The trochlear cleft: the ''black line'' of the trochlear trough

    International Nuclear Information System (INIS)

    Wissman, Robert D.; Nepute, Joshua; Fischer, Nathaniel von; Radhakrishnan, Rupa; Hendry, Daniel; Ingalls, Jerrell; Kenter, Keith

    2012-01-01

    The ''cartilage black line sign'' is a recently described T2 dark cartilage lesion that we have identified appearing as a cleft in the trochlear trough. The purpose of our study was to define the MR imaging characteristics of a trochlear cleft, determine its incidence, and correlate the MR findings with arthroscopy. A total of 1,300 consecutive MR examinations of the knee were retrospectively reviewed by consensus of two fellowship-trained musculoskeletal radiologists. The MR imaging characteristics and location of a trochlear cleft were determined. Imaging results were compared to arthroscopy when available. Patient age and gender were compared to 25 randomly selected control patients without trochlear clefts. A total of 25 (1.9%) individuals (11 females and 14 males; age range 19-45 years; mean age 28 years) were diagnosed with a trochlear cleft. The control group consisted of 11 females and 14 males; age range 19-83 years; mean age 46 years. Mean cleft length was 7 mm (range 6-12 mm); cleft location was consistently in the lower trochlear trough. No full-thickness cartilage defects were identified in the eight individuals in whom arthroscopic correlation was available. A grade 2 cartilage lesion was identified in a single individual; another progressed from grade 0 to a full-thickness trochlear lesion over an 8-month interval. Eight individuals were athletes. No significant difference in gender was noted between the two groups, however, the study group was significantly younger p < 0.0001. A trochlear cleft is a rare finding in young active individuals. It most likely indicates an incomplete cartilage fissure which may rarely progress to a full-thickness defect. (orig.)

  9. An experimental study of thermal characterization of parabolic trough receivers

    International Nuclear Information System (INIS)

    Lei, Dongqiang; Li, Qiang; Wang, Zhifeng; Li, Jian; Li, Jianbin

    2013-01-01

    Highlights: ► A new test stand of heat loss has been developed at IEECAS. ► A correlation between heat loss and absorber temperature is presented, 270 W/m 400 °C. ► The ratio of end loss in total heat loss increases with decreasing the temperature. ► The emittance test stand using a high vacuum system and vacuum gauge is built. ► Emittance first decreases, then rapidly increases with increasing the temperature. - Abstract: The receiver is a key component of the parabolic trough solar station. The receiver requires the most challenging technology and has a decisive influence on the thermal and economic performance of a power plant. The Institute of Electrical Engineering Chinese Academy Sciences (IEECAS) and Himin Solar Co., Ltd. (HSC) cooperated to develop solar receivers for the first 50 MW parabolic trough project in Inner Mongolia, China. This paper examines overall heat loss, end loss and thermal emittance of the coating of a newly designed receiver in order to evaluate its thermal characterization. A series of heat loss tests are conducted in a newly developed test stand following the steady state equilibrium method. The tests provide a correlation between heat loss and the absorber temperature. This paper presents a new testing method to accurately test the coating emittance. The method uses a receiver with a high vacuum system and a vacuum gauge to maintain continuous exhaust and high vacuum throughout the heat loss testing. A heat loss comparison between the receiver and other existing receivers provides a reference that enabled further optimization. Theoretical and experimental analysis examines the effects of end loss both with and without a heat insulator and a coil heater. The emittance curves of different coatings are acquired and the reasons for initial emittance decrease and then remarkable increase versus temperature are analyzed

  10. Methane hydrate morphology of natural hydrate-bearing sediment from Nankai trough, Japan

    Science.gov (United States)

    Konno, Y.; Jin, Y.; Yoneda, J.; Kida, M.; Nagao, J.

    2016-12-01

    As a part of MH21, the Research Consortium for Methane Hydrate Resources in Japan, who initiated Japan's Methane Hydrate R&D Program (managed by the Ministry of Economy, Trade, and Industry (METI)), we developed newly pressured hydrate sediment analyzing apparatus (Pressured Non-destructive Analysis Tools, here after PNATs) including an X-ray computed-tomography (CT) system, gamma-ray density measurement system, an instrumented pressure testing chamber (IPTC). The Japanese IPTC was developed with strong cooperation from Georgia Tech and the U.S. Geological Survey. In this study, we investigated the hydrate morphology in natural gas hydrate-bearing (GH) sediment recovered from eastern Nankai trough area under hydro-pressurized condition using PNATs. In addition to P-wave measurement via the IPTC, we assessed hydrate saturation Sh in sediment sample by using our newly ATR-IR probe for the IPTC. Our analysis reveals that the pressurized sample shows load-bearing GH sediment.

  11. Hydrosweep Measurements During the Expedition ARK XX-2 to Lena Trough and Western Gakkel Ridge

    Science.gov (United States)

    Gauger, S.; Kohls, T.; Roeber, S.; Snow, J.

    2004-12-01

    The region of Lena Trough and Western Gakkel Ridge in the Arctic Ocean was the object of an expedition in the summer of 2004. This region is of particular geoscientific interest because of its extremely slow spreading rates and the variety of morphologic forms that are produced in this tectonic environment. Therefore, the multibeam measurement system was of particular importance to the scientific goals of the cruise. The main characteristic of the Hydrosweep DS-2 deep-water sounding system aboard RV Polarstern is the 90° or 120° coverage angle in which the seafloor is depicted with 59 specific values for water depths perpendicular to the ship's long axis. The accuracy of the measurement is approx. 1% of water depth, the frequency of the acoustic signal is 15.5 kHz. The refraction of the sonar beams was corrected by automatic crossfan calibration. By regular transmission and measurement of a sweep profile in the ship's longitudinal direction and comparison of the slant beams with the vertical beam, the mean sound velocity over the vertical water column is determined and is used for the depth computation. The data collected include depth, sidescan (2048 values per scan), and backscatter information on each of the 59 beams. During this cruise, the Lena Trough was surveyed systematically for the first time by a multibeam sonar system. The recorded area has an expanse of approx. 100000 km2 and connects previously mapped areas of the Eurasian - North-American plate boundary between Fram Strait and Gakkel Ridge. The region of Western Gakkel Ridge, mapped in 2001 (AMOR-Expedition) by RV Polarstern and USCGC Healy (USA), was extended by two more profiles (each 220 km long) along the ridge. In order to produce working maps for the expedition, the multibeam sonar data were gridded with a spacing of 50 m, producing plots with various contour line intervals. For further morphological interpretation of Lena Trough and Gakkel Ridge slope magnitude maps, slope direction maps and

  12. Nevirapine- versus Efavirenz-based antiretroviral therapy regimens in antiretroviral-naive patients with HIV and Tuberculosis infections in India: a multi-centre study.

    Science.gov (United States)

    Sinha, Sanjeev; Gupta, Kartik; Tripathy, Srikanth; Dhooria, Sahajal; Ranjan, Sanjay; Pandey, R M

    2017-12-11

    According to World Health Organization (WHO) guidelines, which have also been adopted by the National AIDS Control Organization (NACO), India, Efavirenz-based Anti-Retroviral Therapy (ART) is better in Human-Immunodeficiency-Virus (HIV)-infected patients who are also being treated with Rifampicin-based Anti-Tuberculous Therapy (ATT). However, Efavirenz is much more expensive. We hypothesize that Nevirapine is a cheaper alternative that possesses equal efficacy as Efavirenz in HIV-Tuberculosis (TB) co-infected patients. A parallel open-label randomized clinical trial was conducted at All India Institute of Medical Sciences (AIIMS), New Delhi and National AIDS Research Institute (NARI), Pune. Those who were ART-naïve and co-infected with TB were randomized to receive either Nevirapine (Group 1)- or Efavirenz (Group 2)-based ART along with Rifampicin-based ATT. ATT was begun first in ART-naïve patients according to the NACO guidelines, with a median of 27 days between ATT and ART in both groups. The primary endpoint was a composite unfavourable outcome (death and/or ART failure) at 96 weeks, and the secondary outcome was successful TB treatment at 48 weeks. A total of 284 patients (mean age 36.7 ± 8.1 years) were randomized in a 1:1 ratio to receive either Nevirapine (n = 144)- or Efavirenz (n = 140)-based ART after a median ATT-ART gap of 27 days. The median CD4 count was 105 cells/μl, with a median viral load of 820,200 copies/μl and no significant difference between the groups. Composite unfavourable outcomes were reported in 49 patients in the Nevirapine group and 51 patients in the Efavirenz group (35.3% vs. 36.9%; hazard ratio, 0.95, 95% confidence interval (CI), 0.63,1.43, adjusted). There was no difference in successful TB treatment outcome between the groups (71.5% vs. 65.6%, 95% CI -3.8,17.9, adjusted). The results were similar, showing no difference between the groups in the two centres of the study after adjusting for disease stage

  13. A retrospective cohort analysis comparing pregnancy rates among HIV-positive women using contraceptives and efavirenz- or nevirapine-based antiretroviral therapy in Kenya

    Science.gov (United States)

    PATEL, Rena C.; ONONO, Maricianah; GANDHI, Monica; BLAT, Cinthia; HAGEY, Jill; SHADE, Starley B.; VITTINGHOFF, Eric; BUKUSI, Elizabeth A.; NEWMANN, Sara J.; COHEN, Craig R.

    2015-01-01

    SUMMARY Background Given recent concerns of efavirenz reducing the efficacy of contraceptive implants, we sought to determine if pregnancy rates differ among HIV-positive women using various contraceptive methods and efavirenz- or nevirapine-based antiretroviral therapy (ART) regimens. Methods We conducted a retrospective cohort analysis of HIV-positive women aged 15–45 years enrolled in HIV care facilities in western Kenya from January 2011 to December 2013. Pregnancy was diagnosed clinically and the primary exposure was a combination of contraceptive method and ART regimen. We used Poisson models, adjusting for repeated measures, as well as demographic, behavioral and clinical factors, to compare pregnancy rates among women on different contraceptive/ART combinations. Findings 24,560 women contributed 37,635 years of follow-up with 3,337 incident pregnancies. Among women using implants, adjusted pregnancy incidence for nevirapine- and efavirenz-based ART users were 1·1 (95% CI 0·72–1·5) and 3·3 (95% CI 1·8–4·8) per 100 women-years (w-y), respectively (adjusted incidence rate ratio (aIRR) 3·0, 95% CI 1·3–4·6). Among women using depomedroxyprogesterone acetate (DMPA), adjusted pregnancy incidence for nevirapine- and efavirenz-based ART users were 4·5 (95% CI 3·7–5·2) and 5·4 (95% CI 4·0–6·8) per 100 w-y, respectively (aIRR 1·2, 95% CI 0·91–1·5). Women using other contraceptive methods, except for intrauterine devices and permanent methods, experienced 3·1–4·1 higher rates of pregnancy than women using implants, with 1·6–2·8 higher rates specifically among women using efavirenz-based ART. Interpretation While HIV-positive women using implants on efavirenz-based ART faced three times higher risk of contraceptive failure than those on nevirapine-based ART, these women still experienced lower contraceptive failure rates than women on all other contraceptive methods, except for intrauterine devices and permanent methods

  14. A cluster-randomized trial of enhanced labor ward-based PMTCT services to increase nevirapine coverage in Lusaka, Zambia.

    Science.gov (United States)

    Megazzini, Karen M; Sinkala, Moses; Vermund, Sten H; Redden, David T; Krebs, Daniel W; Acosta, Edward P; Mwanza, Joyce; Goldenberg, Robert L; Chintu, Namwinga; Bulterys, Marc; Stringer, Jeffrey Sa

    2010-01-28

    Determine whether enhanced labor ward-based services for prevention of mother-to-child transmission of HIV (PMTCT) would improve nevirapine (NVP) coverage. Cluster-randomized trial at 12 public-sector delivery centers in Lusaka, Zambia. Following a baseline surveillance period, 12 labor wards were randomized, six to offer opt-in HIV testing to women of unknown serostatus (with NVP administration as indicated) and to assess NVP adherence among known HIV-infected women. The six control labor wards provided the standard of care. The NVP coverage endpoint was defined as the proportion of HIV-infected/exposed women/infant pairs with confirmed NVP ingestion. We used generalized estimating equations (GEE) to determine the odds of coverage associated with the intervention and ultimately used the parameters for the estimated GEE model to estimate relative risk. Between October 2005 and January 2006, 7664 women gave birth at participating clinics. We collected anonymous-linked blood from 7592 (99%) umbilical cords; tested 7438 (97%) for HIV, 1618 (22%) were seropositive, and of these, 1279 (79%) were tested for NVP. At baseline (preintervention), the probability of HIV-infected/exposed women/infant pairs receiving NVP in treatment clinics (42%) was 0.89 times the probability of being covered in control clinics (53%) whereas during the intervention period the probability of treatment clinic coverage (52%) was 1.22 the probability control clinic coverage (43%), representing a multiplicative effect of 1.37 upon the RR at baseline (ratio of relative risks 1.37, bootstrapped 95% CI, 1.04-1.77). Labor ward-based PMTCT programs are feasible and can have a significant, positive impact on NVP coverage.

  15. New Geological Evidence of Past Earthquakes and Tsunami Along the Nankai Trough, Japan

    Science.gov (United States)

    De Batist, M. A. O.; Heyvaert, V.; Hubert-Ferrari, A.; Fujiwara, O.; Shishikura, M.; Yokoyama, Y.; Brückner, H.; Garrett, E.; Boes, E.; Lamair, L.; Nakamura, A.; Miyairi, Y.; Yamamoto, S.

    2015-12-01

    The east coast of Japan is prone to tsunamigenic megathrust earthquakes, as tragically demonstrated in 2011 by the Tōhoku earthquake (Mw 9.0) and tsunami. The Nankai Trough subduction zone, to the southwest of the area affected by the Tōhoku disaster and facing the densely populated and heavily industrialized southern coastline of central and west Japan, is expected to generate another megathrust earthquake and tsunami in the near future. This subduction zone is, however, segmented and appears to be characterized by a variable rupture mode, involving single- as well as multi-segment ruptures, which has immediate implications for their tsunamigenic potential, and also renders the collection of sufficiently long time records of past earthquakes and tsunami in this region fundamental for an adequate hazard and risk assessment. Over the past three decades, Japanese researchers have acquired a large amount of geological evidence of past earthquakes and tsunami, in many cases extending back in time for several thousands of years. This evidence includes uplifted marine terraces, turbidites, liquefaction features, subsided marshes and tsunami deposits in coastal lakes and lowlands. Despite these efforts, current understanding of the behaviour of the subduction zone still remains limited, due to site-specific evidence creation and preservation thresholds and issues over alternative hypotheses for proposed palaeoseismic evidence and insufficiently precise chronological control. Within the QuakeRecNankai project we are generating a long and coherent time series of megathrust earthquake and tsunami recurrences along the Nankai Trough subduction zone by integrating all existing evidence with new geological records of paleo-tsunami in the Lake Hamana region and of paleo-earthquakes from selected lakes in the Mount Fuji area. We combine extensive fieldwork in coastal plain areas and lakes, with advanced sedimentological and geochemical analyses and innovative dating techniques.

  16. The Tethys Rifting of the Valencia Trough Basin

    Science.gov (United States)

    Viñas, Marina; Ranero, César R.; Cameselle, Alejandra L.

    2017-04-01

    The western Mediterranean submarine realm is composed of several basin inferred to be formed by a common geodynamic process: upper plate extension during slab rollback of a retreating subduction zone. Although the time evolution of the geometry of the trenches is debated, all models assume that basins opened sequentially from NW (Gulf of Lions) towards the SE (Ligurian-Provençal and later Tyrrhenian basins) and SW (Valencia Trough and later Algerian-South Balearic and Alboran Basin) as trenches migrated. Basin opening history is key to reconstruct kinematics of slab retreat preferred in each model. However, the deep structure of basins is inadequately known due to the paucity of modern wide-angle and multichannel reflection seismic studies across entire systems, and absence of deep drilling in the deep-water regions of the basins, as a result, much of the opening evolution is inferred from indirect evidence. In the Valencia Trough Basin (VTB), drilling and vintage seismic data provide good knowledge of the shallow geology of the basin. However, crustal-scale information across the entire VTB has been limited to two studies (Figure 1): One in the late 80's (Valsis experiment) with three Expanded Spread Profiles that yielded local 1D velocity/depth models used to constrain 2D gravity modeling, and a few multichannel seismic profiles along the Iberian shelf and across segments of the basin. A second study in the early 90's (ESCI experiment) collected a low-resolution deep-penetration multichannel seismic reflection profile across the basin and a coincident wide-angle seismic line with numerous land stations in Iberia but a handful of widely-spaced Ocean Bottom Seismometers. In the absence of modern detailed crustal structure, the origin and evolution of the VTB is still debated. Industry multichannel seismic reflection profiles cover the SW segment of the VTB. This is a region where the basin sea floor is comparatively shallower and has numerous industry wells

  17. Economic analysis of power generation from parabolic trough solar thermal plants for the Mediterranean region. A case study for the island of Cyprus

    International Nuclear Information System (INIS)

    Poullikkas, Andreas

    2009-01-01

    In this work a feasibility study is carried out in order to investigate whether the installation of a parabolic trough solar thermal technology for power generation in the Mediterranean region is economically feasible. The case study takes into account the available solar potential for Cyprus, as well as all available data concerning current renewable energy sources policy of the Cyprus Government, including the relevant feed-in tariff. In order to identify the least cost feasible option for the installation of the parabolic trough solar thermal plant a parametric cost-benefit analysis is carried out by varying parameters, such as, parabolic trough solar thermal plant capacity, parabolic trough solar thermal capital investment, operating hours, carbon dioxide emission trading system price, etc. For all above cases the electricity unit cost or benefit before tax, as well as after tax cash flow, net present value, internal rate of return and payback period are calculated. The results indicate that under certain conditions such projects can be profitable. (author)

  18. Modelling the main ionospheric trough using the Electron Density Assimilative Model (EDAM) with assimilated GPS TEC

    Science.gov (United States)

    Parker, James A. D.; Eleri Pryse, S.; Jackson-Booth, Natasha; Buckland, Rachel A.

    2018-01-01

    The main ionospheric trough is a large-scale spatial depletion in the electron density distribution at the interface between the high- and mid-latitude ionosphere. In western Europe it appears in early evening, progresses equatorward during the night, and retreats rapidly poleward at dawn. It exhibits substantial day-to-day variability and under conditions of increased geomagnetic activity it moves progressively to lower latitudes. Steep gradients on the trough-walls on either side of the trough minimum, and their variability, can cause problems for radio applications. Numerous studies have sought to characterize and quantify the trough behaviour. The Electron Density Assimilative Model (EDAM) models the ionosphere on a global scale. It assimilates observations into a background ionosphere, the International Reference Ionosphere 2007 (IRI2007), to provide a full 3-D representation of the ionospheric plasma distribution at specified times and days. This current investigation studied the capability of EDAM to model the ionosphere in the region of the main trough. Total electron content (TEC) measurements from 46 GPS stations in western Europe from September to December 2002 were assimilated into EDAM to provide a model of the ionosphere in the trough region. Vertical electron content profiles through the model revealed the trough and the detail of its structure. Statistical results are presented of the latitude of the trough minimum, TEC at the minimum and of other defined parameters that characterize the trough structure. The results are compared with previous observations made with the Navy Ionospheric Monitoring System (NIMS), and reveal the potential of EDAM to model the large-scale structure of the ionosphere.

  19. Parabolic Trough Photovoltaic/Thermal Collectors: Design and Simulation Model

    Directory of Open Access Journals (Sweden)

    Laura Vanoli

    2012-10-01

    Full Text Available This paper presents a design procedure and a simulation model of a novel concentrating PVT collector. The layout of the PVT system under investigation was derived from a prototype recently presented in literature and commercially available. The prototype consisted in a parabolic trough concentrator and a linear triangular receiver. In that prototype, the bottom surfaces of the receiver are equipped with mono-crystalline silicon cells whereas the top surface is covered by an absorbing surface. The aperture area of the parabola was covered by a glass in order to improve the thermal efficiency of the system. In the modified version of the collector considered in this paper, two changes are implemented: the cover glass was eliminated and the mono-crystalline silicon cells were replaced by triple-junction cells. In order to analyze PVT performance, a detailed mathematical model was implemented. This model is based on zero-dimensional energy balances. The simulation model calculates the temperatures of the main components of the system and the main energy flows Results showed that the performance of the system is excellent even when the fluid temperature is very high (>100 °C. Conversely, both electrical and thermal efficiencies dramatically decrease when the incident beam radiation decreases.

  20. Origin and model of transform faults in the Okinawa Trough

    Science.gov (United States)

    Liu, Bo; Li, Sanzhong; Jiang, Suhua; Suo, Yanhui; Guo, Lingli; Wang, Yongming; Zhang, Huixuan

    2017-06-01

    Transform faults in back-arc basins are the key to revealing the opening and development of marginal seas. The Okinawa Trough (OT) represents an incipient and active back-arc or marginal sea basin oriented in a general NE-SW direction. To determine the strikes and spatial distribution of transform faults in the OT, this paper dissects the NW- and NNE-SN-trending fault patterns on the basis of seismic profiles, gravity anomalies and region geological data. There are three main NW-trending transpressional faults in the OT, which are the seaward propagation of NW-trending faults in the East China Continent. The NNE-SN-trending faults with right-stepping distribution behave as right-lateral shearing. The strike-slip pull-apart process or transtensional faulting triggered the back-arc rifting or extension, and these faults evolved into transform faults with the emergence of oceanic crust. Thus, the transform fault patterns are inherited from pre-existing oblique transtensional faults at the offsets between rifting segments. Therefore, the OT performs the oblique spreading mechanism similar to nascent oceans such as the Red Sea and Gulf of Aden.

  1. A Process Heat Application Using Parabolic Trough Collector

    Science.gov (United States)

    Yılmaz, İbrahim Halil; Söylemez, Mehmet Sait; Hayta, Hakan; Yumrutaş, Recep

    A pilot study has been performed based on a heat process application that is designed, installed and tested at Gaziantep University to establish the technical and economic feasibility of high temperature solar-assisted cooking process. The system has been designed to be satisfying the process conditions integrated with parabolic trough solar collector (PTSC). It is primarily consists of the PTSC array, auxiliary heater, plate type heat exchanger, cooking system and water heating tanks. In the operation of the process heat application, the energy required to cook wheat (used as cooking material) has been supplied from solar energy which is transferred to heat transfer fluid (HTF) by heat exchanging units and finally discharged to water in order to produce bulgur. The performance parameters of the sub-systems and the process compatibility have been accomplished depending on the system operation. In addition that the system performance of the high temperature solar heat process has been presented and the recommendations on its improvement have been evaluated by performing an experimental study. As a result that the use of solar energy in process heat application has been projected and its contribution to economics view with respect to conventional cooking systems has been conducted.

  2. Distinct control mechanism of fine-grained sediments from Yellow River and Kyushu supply in the northern Okinawa Trough since the last glacial

    Science.gov (United States)

    Zhao, Debo; Wan, Shiming; Toucanne, Samuel; Clift, Peter D.; Tada, Ryuji; Révillon, Sidonie; Kubota, Yoshimi; Zheng, Xufeng; Yu, Zhaojie; Huang, Jie; Jiang, Hanchao; Xu, Zhaokai; Shi, Xuefa; Li, Anchun

    2017-08-01

    High-resolution multiproxy records, including clay minerals and Sr-Nd-Pb isotopes of the clay-sized silicate fraction of sediments from IODP Site U1429 in the northern Okinawa Trough, provide reliable evidence for distinct control mechanism on fine-grained sediments input from the Yellow River and the southern Japanese Islands to the northern Okinawa Trough since 34 ka BP. Provenance analysis indicates that the sediments were mainly derived from the Yellow River and the island of Kyushu. Since the last glacial, clay-sized sediments transported from the Yellow River to the study site were strongly influenced by sea-level fluctuation. During low sea-level stage (˜34-14 ka BP), the paleo-Yellow River mouth was positioned closer to the northern Okinawa Trough, favoring large fluvial discharge or even direct input of detrital sediments, which resulted about four times more flux of clay-sized sediments supply to the study area as during the relatively high sea-level stage (˜14-0 ka BP). The input of Kyushu-derived clay-sized sediments to the study site was mainly controlled by the Kuroshio Current and Tsushima Warm Current intensity, with increased input in phase with weakened Kuroshio Current/Tsushima Warm Current. Our study suggests that the Kuroshio Current was very likely flowed into the Okinawa Trough and thus influenced the fine-grained sediment transport in the area throughout the last glacial and deglacial. During ˜34-11 ka BP, the Kyushu clay-sized sediment input was mainly controlled by the Kuroshio Current. Since ˜11 ka BP, the occurrence of Tsushima Warm Current became important in influencing the Kyushu fine-grained sediment input to the northern Okinawa Trough.

  3. Patient-reported non-adherence and immunosuppressant trough levels are associated with rejection after renal transplantation.

    Science.gov (United States)

    Scheel, Jennifer; Reber, Sandra; Stoessel, Lisa; Waldmann, Elisabeth; Jank, Sabine; Eckardt, Kai-Uwe; Grundmann, Franziska; Vitinius, Frank; de Zwaan, Martina; Bertram, Anna; Erim, Yesim

    2017-03-29

    Different measures of non-adherence to immunosuppressant (IS) medication have been found to be associated with rejection episodes after successful transplantation. The aim of the current study was to investigate whether graft rejection after renal transplantation is associated with patient-reported IS medication non-adherence and IS trough level variables (IS trough level variability and percentage of sub-therapeutic IS trough levels). Patient-reported non-adherence, IS trough level variability, percentage of sub-therapeutic IS trough levels, and acute biopsy-proven late allograft rejections were assessed in 267 adult renal transplant recipients who were ≥12 months post-transplantation. The rate of rejection was 13.5%. IS trough level variability, percentage of sub-therapeutic IS trough levels as well as patient-reported non-adherence were all significantly and positively associated with rejection, but not with each other. Logistic regression analyses revealed that only the percentage of sub-therapeutic IS trough levels and age at transplantation remained significantly associated with rejection. Particularly, the percentage of sub-therapeutic IS trough levels is associated with acute rejections after kidney transplantation whereas IS trough level variability and patient-reported non-adherence seem to be of subordinate importance. Patient-reported non-adherence and IS trough level variables were not correlated; thus, non-adherence should always be measured in a multi-methodological approach. Further research concerning the best combination of non-adherence measures is needed.

  4. Wind Tunnel Tests of Parabolic Trough Solar Collectors: March 2001--August 2003

    Energy Technology Data Exchange (ETDEWEB)

    Hosoya, N.; Peterka, J. A.; Gee, R. C.; Kearney, D.

    2008-05-01

    Conducted extensive wind-tunnel tests on parabolic trough solar collectors to determine practical wind loads applicable to structural design for stress and deformation, and local component design for concentrator reflectors.

  5. Report on Radiocarbon Analysis of Surface Sediments from the Fore-Arc Basin of Nankai Trough

    National Research Council Canada - National Science Library

    Pohlman, John

    2004-01-01

    .... Radiocarbon analysis of the total organic carbon (TOC) and total inorganic carbon (TIC) on 30 sediment samples from two multicores and six piston cores was performed to investigate the fate of methane carbon in sediment of the Nankal Trough...

  6. Assessment of undiscovered continuous oil and gas resources in the Hanoi Trough, Vietnam, 2017

    Science.gov (United States)

    Schenk, Christopher J.; Tennyson, Marilyn E.; Mercier, Tracey J.; Woodall, Cheryl A.; Le, Phuong A.; Klett, Timothy R.; Finn, Thomas M.; Leathers-Miller, Heidi M.; Gaswirth, Stephanie B.; Marra, Kristen R.

    2018-02-13

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered, technically recoverable continuous resources of 52 million barrels of oil and 591 billion cubic feet of gas in the Hanoi Trough of Vietnam.

  7. Determination of Elastic Parameters of Near-Surface Layers Over Subsidence Trough Development During Longwall Exploitation

    Science.gov (United States)

    Mendecki, Maciej J.; Jochymczyk, Krzysztof; Zuberek, Wacław M.; Tomaszewska, Radosława

    2017-12-01

    Seismic and geodetic studies were carried out before, during, and after underground exploitation of a coal bed in Katowice - Kleofas Coal Mine, located in the Upper Silesia Coal Basin, Poland. Development of a subsidence trough was completed approximately 3 months after passage of a longwall exploitation in the coal seam. This was the time required for the subsidence trough to appear on the surface, which was confirmed by levelling measurements. Sharp changes in the elastic parameters were observed on each profile during subsidence trough development. This observation can result from changing tension and compression forces caused by increase and/or decrease of the elastic parameters of the rock mass. After completion of subsidence trough development, the rock mass appeared to return to its isotropic state and the observed changes ceased. Some minor fluctuations were noted, but they probably resulted from changes in groundwater levels, which might have affected the measured parameters.

  8. Validated RP-HPLC-PDA method for simultaneous determination of Zidovudine, Lamivudine, and Nevirapine in pharmaceutical formulation

    Directory of Open Access Journals (Sweden)

    B Mohammed Ishaq

    2015-01-01

    Full Text Available Aim and Objectives: A simple, rapid, and sensitive high performance liquid chromatographic method with ultraviolet detection has been developed and validated according to the International Conference on Harmonization (ICH guidelines for the quantitation and qualification of zidovudine (ZID, lamivudine (LAM, and nevirapine (NEV in pharmaceutical dosage forms. Materials and Methods: The proposed method was based on the separation of the drugs in reversed phase mode using Water′s C18 250 cm × 4.6 mm, 5 μ particle size column maintained at an ambient temperature. The optimum mobile phase consisted of Water: Methanol (70:30 v/v, pH adjusted to four with orthophosphoric acid (OPA. The flow rate of mobile phase was set 1.0 mL min -1 and photodiode array detection was performed at 275 nm with a total run time of 8 min which is very short for accurate analysis of simultaneous estimation of three analytes. The method was validated according to ICH guidelines. Results: The method was linear over the concentration range of 25-75 μg mL -1 with limit of quantifications (LOQ of 13, 0.49, and 0.40 ng mL -1 for ZID, LAM and NEV respectively and limit of detection (LOD of 4, 0.14, and 0.12 ng mL -1 for ZID, LAM and NEV respectively. Accuracy (% recovery studies and precision values of both inter and intraday obtained from six different replicates for all the analytes ranged from 99.00% to 100.00% and % relative standard deviation of precision (assay was between 0.64 and 1.28, respectively. All the three analytes and their combination drug product were exposed to thermal, photolytic, hydrolytic, reductive, oxidative and peroxide stress conditions and the stressed samples were analyzed by the proposed method. There were no interfering peaks from excipients, impurities or degradation products due to variable stress conditions and the proposed method is specific for the simultaneous estimation of ZID, LAM and NEV in the presence of their degradation products

  9. Nevirapine and efavirenz elicit different changes in lipid profiles in antiretroviral-therapy-naive patients infected with HIV-1.

    Directory of Open Access Journals (Sweden)

    Frank van Leth

    2004-10-01

    Full Text Available BACKGROUND: Patients infected with HIV-1 initiating antiretroviral therapy (ART containing a non-nucleoside reverse transcriptase inhibitor (NNRTI show presumably fewer atherogenic lipid changes than those initiating most ARTs containing a protease inhibitor. We analysed whether lipid changes differed between the two most commonly used NNRTIs, nevirapine (NVP and efavirenz (EFV. METHODS AND FINDINGS: Prospective analysis of lipids and lipoproteins was performed in patients enrolled in the NVP and EFV treatment groups of the 2NN study who remained on allocated treatment during 48 wk of follow-up. Patients were allocated to NVP (n = 417, or EFV (n = 289 in combination with stavudine and lamivudine. The primary endpoint was percentage change over 48 wk in high-density lipoprotein cholesterol (HDL-c, total cholesterol (TC, TC:HDL-c ratio, non-HDL-c, low-density lipoprotein cholesterol, and triglycerides. The increase of HDL-c was significantly larger for patients receiving NVP (42.5% than for patients receiving EFV (33.7%; p = 0.036, while the increase in TC was lower (26.9% and 31.1%, respectively; p = 0.073, resulting in a decrease of the TC:HDL-c ratio for patients receiving NVP (-4.1% and an increase for patients receiving EFV (+5.9%; p < 0.001. The increase of non-HDL-c was smaller for patients receiving NVP (24.7% than for patients receiving EFV (33.6%; p = 0.007, as were the increases of triglycerides (20.1% and 49.0%, respectively; p < 0.001 and low-density lipoprotein cholesterol (35.0% and 40.0%, respectively; p = 0.378. These differences remained, or even increased, after adjusting for changes in HIV-1 RNA and CD4+ cell levels, indicating an effect of the drugs on lipids over and above that which may be explained by suppression of HIV-1 infection. The increases in HDL-c were of the same order of magnitude as those seen with the use of the investigational HDL-c-increasing drugs. CONCLUSION: NVP-containing ART shows larger increases in HDL

  10. Influence of pen area and trough space on feedlot performance of ...

    African Journals Online (AJOL)

    Two exoeriments were conducted to measure the influence of trough space (170 mm, 350 mm and 700 mm/animal) and pen area (5,5 m2, 11 m2 and 22 mzlanimal) on feedlot performance. There was no advantage in allowing more than 170 mm trough space or more than 5,5 m2 floor area per animal with the conditions ...

  11. Development of Molten-Salt Heat Transfer Fluid Technology for Parabolic Trough Solar Power Plants - Public Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Grogan, Dylan C. P.

    2013-08-15

    Executive Summary This Final Report for the "Development of Molten-Salt Heat Transfer Fluid (HTF) Technology for Parabolic Trough Solar Power Plants” describes the overall project accomplishments, results and conclusions. Phase 1 analyzed the feasibility, cost and performance of a parabolic trough solar power plant with a molten salt heat transfer fluid (HTF); researched and/or developed feasible component options, detailed cost estimates and workable operating procedures; and developed hourly performance models. As a result, a molten salt plant with 6 hours of storage was shown to reduce Thermal Energy Storage (TES) cost by 43.2%, solar field cost by 14.8%, and levelized cost of energy (LCOE) by 9.8% - 14.5% relative to a similar state-of-the-art baseline plant. The LCOE savings range met the project’s Go/No Go criteria of 10% LCOE reduction. Another primary focus of Phase 1 and 2 was risk mitigation. The large risk areas associated with a molten salt parabolic trough plant were addressed in both Phases, such as; HTF freeze prevention and recovery, collector components and piping connections, and complex component interactions. Phase 2 analyzed in more detail the technical and economic feasibility of a 140 MWe,gross molten-salt CSP plant with 6 hours of TES. Phase 2 accomplishments included developing technical solutions to the above mentioned risk areas, such as freeze protection/recovery, corrosion effects of applicable molten salts, collector design improvements for molten salt, and developing plant operating strategies for maximized plant performance and freeze risk mitigation. Phase 2 accomplishments also included developing and thoroughly analyzing a molten salt, Parabolic Trough power plant performance model, in order to achieve the project cost and performance targets. The plant performance model and an extensive basic Engineering, Procurement, and Construction (EPC) quote were used to calculate a real levelized cost of energy (LCOE) of 11.50

  12. Geological modeling for methane hydrate reservoir characterization in the eastern Nankai Trough, offshore Japan

    Science.gov (United States)

    Tamaki, M.; Komatsu, Y.; Suzuki, K.; Takayama, T.; Fujii, T.

    2012-12-01

    The eastern Nankai trough, which is located offshore of central Japan, is considered as an attractive potential resource field of methane hydrates. Japan Oil, Gas and Metals National Corporation is planning to conduct a production test in early 2013 at the AT1 site in the north slope of Daini-Atsumi Knoll in the eastern Nankai Trough. The depositional environment of methane hydrate-bearing sediments around the production test site is a deep submarine-fan turbidite system, and it is considered that the reservoir properties should show lateral as well as vertical heterogeneity. Since the variations in the reservoir heterogeneity have an impact on the methane hydrate dissociation and gas production performance, precise geological models describing reservoir heterogeneity would be required for the evaluation of reservoir potentials. In preparation for the production test, 3 wells; two monitoring boreholes (AT1-MC and AT1-MT1) and a coring well (AT1-C), were newly acquired in 2012. In addition to a geotechnical hole drilling survey in 2011 (AT1-GT), totally log data from 2 wells and core data from 2 wells were obtained around the production test site. In this study, we conducted well correlations between AT1 and A1 wells drilled in 2003 and then, 3D geological models were updated including AT1 well data in order to refine hydrate reservoir characterization around the production test site. The results of the well correlations show that turbidite sand layers are characterized by good lateral continuity, and give significant information for the distribution morphology of sand-rich channel fills. We also reviewed previously conducted 3D geological models which consist of facies distributions and petrophysical properties distributions constructed from integration of 3D seismic data and a well data (A1 site) adopting a geostatistical approach. In order to test the practical validity of the previously generated models, cross-validation was conducted using AT1 well data. The

  13. IODP Expedition 331: Strong and Expansive Subseafloor Hydrothermal Activities in the Okinawa Trough

    Directory of Open Access Journals (Sweden)

    the IODP Expedition 331 Scientists

    2012-04-01

    Full Text Available Integrated Ocean Drilling Program (IODP Expedition 331 drilled into the Iheya North hydrothermal system in the middle Okinawa Trough in order to investigate active subseafloor microbial ecosystems and their physical and chemical settings. We drilled five sites during Expedition 331 using special guide bases at three holes for reentry, casing, and capping, including installation of a steel mesh platformwith valve controls for postcruise sampling of fluids. At Site C0016, drilling at the base of the North Big Chimney (NBCmound yielded low recovery, but core included the first Kuroko-type black ore ever recovered from the modern subseafloor. The other four sites yielded interbedded hemipelagic and strongly pumiceous volcaniclastic sediment, along with volcanogenic breccias that are variably hydrothermally altered and mineralized. At most sites, analyses of interstitial water and headspace gas yielded complex patterns withdepth and lateral distance of only a few meters. Documented processes included formation of brines and vapor-rich fluids by phase separation and segregation, uptake of Mg and Na by alteration minerals in exchange for Ca, leaching of K at high temperature and uptake at low temperature, anhydrite precipitation, potential microbial oxidation of organic matter and anaerobic oxidation of methane utilizing sulfate, and methanogenesis. Shipboard analyses have found evidence for microbial activity in sediments within the upper 10–30 m below seafloor (mbsf where temperatures were relativelylow, but little evidence in the deeper hydrothermally altered zones and hydrothermal fluid regime.

  14. Evidence for a Slow Spreading Ocean Ridge in the Southern Rockall Trough From Satellite Gravity Inversion and Seismic Data

    Science.gov (United States)

    Chappell, A. R.; Kusznir, N. J.

    2005-12-01

    seismic crust with some serpentinised mantle material included. We propose that the southern Rockall Trough was formed by continental break-up and a period of slow mid Cretaceous sea floor spreading rather than as an intra- continental rift basin. This work forms part of the NERC Margins iSIMM project. iSIMM investigators are from Liverpool and Cambridge Universities, Badley Geoscience & Schlumberger Cambridge Research supported by the NERC, the DTI, Agip UK, BP, Amerada Hess Ltd, Anadarko, Conoco-Phillips, Shell, Statoil and WesternGeco. The iSIMM team comprises NJ Kusznir, RS White, AM Roberts, PAF Christie, AR Chappell, J Eccles, RJ Fletcher, D Healy, N Hurst, ZC Lunnon, CJ Parkin, AW Roberts, LK Smith, VJ Tymms & R Spitzer.

  15. Fresh water seepage and pore water recycling on the seafloor: Sagami Trough subduction zone, Japan

    Science.gov (United States)

    Tsunogai, U.; Ishibashi, J.; Wakita, H.; Gamo, T.; Masuzawa, T.; Nakatsuka, T.; Nojiri, Y.; Nakamura, T.

    1996-02-01

    We collected 19 samples of bottom sea water (including 8 samples of shimmering fluid), using the Japanese submersible Shinkai 2000, in the bathyal Calyptogena community area (the Hatsushima area) along Sagami Trough, at the northern end of the Philippine Sea plate, in order to clarify the source of fluid seepage. Shimmering fluid samples showed a maximum temperature of 11.6°C, which is about 9°C higher than the ambient sea water. The fluid chemistry of these samples is summarized as follows: (1) alkalinity, H 2S, SiO 2, NH 4, ΣCO 2 and CH 4 show enrichment and Cl, SO 4, K, Na, Mg and Ca show depletion compared with ambient sea water; (2) Cl depletion is about 20%; and (3) the content and 3He/4He ratio of dissolved helium show little anomaly compared with ambient sea water. The observed chemical composition and temperature of the fluid is well explained by mixing of sea water, pore water and land-derived groundwater with a temperature of about 40°C and a seeping flux of about 400 m 3 per day. A preliminary estimation of the global chemical flux implies that groundwater discharge to the ocean (including pore water recycling) is an important factor in controlling ocean chemistry.

  16. Marine sedimentary record of the Greenpeace Trough, Larsen A embayment, Antarctic Peninsula

    Science.gov (United States)

    Crawford, A.; Leventer, A.; Domack, E. W.; Brachfeld, S. A.

    2010-12-01

    During research cruise NBP0003 of the Nathaniel B. Palmer, a suite of sediment cores were recovered from the Greenpeace Trough, an inner shelf feature reaching depths > 1000 meters. The trough is located within the northernmost embayment along the eastern side of the Antarctic Peninsula, a region that developed into an open marine setting following the 1995 disintegration of the Larsen A Ice Shelf. Two kasten cores have been studied, NBP0003 KC20 and KC23. Kasten core 20 has a complementary jumbo gravity core, JGC20, which over-penetrated the surface, but recovered deeper sediments and added to the stratigraphic record. The two kasten cores share a common stratigraphy that records the progression from grounded ice, to ice liftoff, to a subaqueous setting. This uppermost unit, a silty-clay, is characterized by moderately high, but variable, diatom abundance (~1-10 million valves/gram dry sediment), and episodically high abundance of fragile valves and girdle bands of the diatom species Corethron. The diatom assemblage is dominated by species from the genera Chaetoceros and Fragilariopsis. These data are indicative of productive, open marine conditions with seasonal sea ice cover, during the mid-Holocene. Recent ice shelf breakout also is documented, by increased diatom abundance in the uppermost sediments. Lower absolute diatom abundance during both the early and late Holocene suggests a sub-ice shelf setting. Within the diamict, diatom abundance is 2-3 orders of magnitude lower than in the overlying sediments, and includes the occurrence of diatom fragments. Diatom and lithologic data from the sedimentary section from the jumbo gravity core indicate an overlap with the lowermost section of the kasten cores and an extension of the stratigraphy into a section characterized by the complete absence of diatom valves or fragments. In addition, the lithology of the sediments, very fine-grained and laminated, differs from the overlying sediments. The observations support

  17.  Risk of discontinuation of nevirapine due to toxicities in antiretroviral naive and experienced HIV-infected patients with high and low CD4 counts

    DEFF Research Database (Denmark)

    Mocroft, A; Staszewski, S; Weber, R

    2007-01-01

    INTRODUCTION: It is unknown whether the increased risk of toxicities in antiretroviral-naive HIV-infected patients initiating nevirapine-based (NVPc) combination antiretroviral therapy (cART) with high CD4+ T-cell counts is also observed when NVPc is initiated in cARTexperienced patients. PATIENTS...... AND METHODS: 1,571 EuroSIDA patients started NVPc after 1/1/1999, with CD4+ T-cell counts and viral load measured in the 6 months before starting treatment, and were stratified into four groups based on CD4+ T-cell counts at initiation of NVPc (high [H], > 400/mm3 or > 250/mm3 for male or female, respectively...... suggest that NVPc might be safer to initiate in antiretroviral-experienced than in antiretroviral-naive patients with high CD4+ T-cell counts....

  18. Nevirapine- versus lopinavir/ritonavir-based initial therapy for HIV-1 infection among women in Africa: a randomized trial.

    Directory of Open Access Journals (Sweden)

    Shahin Lockman

    Full Text Available Nevirapine (NVP is widely used in antiretroviral treatment (ART of HIV-1 globally. The primary objective of the AA5208/OCTANE trial was to compare the efficacy of NVP-based versus lopinavir/ritonavir (LPV/r-based initial ART.In seven African countries (Botswana, Kenya, Malawi, South Africa, Uganda, Zambia, and Zimbabwe, 500 antiretroviral-naïve HIV-infected women with CD4<200 cells/mm(3 were enrolled into a two-arm randomized trial to initiate open-label ART with tenofovir (TDF/emtricitabine (FTC once/day plus either NVP (n = 249 or LPV/r (n = 251 twice/day, and followed for ≥48 weeks. The primary endpoint was time from randomization to death or confirmed virologic failure ([VF] (plasma HIV RNA<1 log(10 below baseline 12 weeks after treatment initiation, or ≥400 copies/ml at or after 24 weeks, with comparison between treatments based on hazard ratios (HRs in intention-to-treat analysis. Equivalence of randomized treatments was defined as finding the 95% CI for HR for virological failure or death in the range 0.5 to 2.0. Baseline characteristics were (median: age = 34 years, CD4 = 121 cells/mm(3, HIV RNA = 5.2 log(10copies/ml. Median follow-up = 118 weeks; 29 (6% women were lost to follow-up. 42 women (37 VFs, five deaths; 17% in the NVP and 50 (43 VFs, seven deaths; 20% in the LPV/r arm reached the primary endpoint (HR 0.85, 95% CI 0.56-1.29. During initial assigned treatment, 14% and 16% of women receiving NVP and LPV/r experienced grade 3/4 signs/symptoms and 26% and 22% experienced grade 3/4 laboratory abnormalities. However, 35 (14% women discontinued NVP because of adverse events, most in the first 8 weeks, versus none for LPV/r (p<0.001. VF, death, or permanent treatment discontinuation occurred in 80 (32% of NVP and 54 (22% of LPV/r arms (HR = 1.7, 95% CI 1.2-2.4, with the difference primarily due to more treatment discontinuation in the NVP arm. 13 (45% of 29 women tested in the NVP versus six (15% of 40

  19. Comparison of Two Strategies for Administering Nevirapine to Prevent Perinatal HIV Transmission in High-Prevalence, Resource-Poor Settings

    Science.gov (United States)

    Stringer, Jeffrey S. A.; Sinkala, Moses; Stout, Julia P.; Goldenberg, Robert L.; Acosta, Edward P.; Chapman, Victoria; Kumwenda-Phiri, Rosemary; Vermund, Sten H.

    2009-01-01

    Summary Universal nevirapine (NVP) therapy (provision of the drug without HIV testing) has been suggested as potentially superior to targeted NVP therapy (provision of the drug to seropositive patients identified through voluntary HIV counseling and testing [VCT]) for perinatal HIV prevention in low-resource, high-prevalence settings. The authors postulated that uptake (the proportion of women who accept the strategy when offered) may be higher for universal therapy, since it does not require a woman to learn her serostatus; they further postulated that adherence (the proportion of women who actually ingest the NVP tablet at labor onset) may be higher for targeted therapy, since knowledge of serostatus could motivate better adherence. Two clinics in Lusaka, Zambia were assigned to provide either the targeted or universal strategy. Halfway through the study period, the approach offered at each clinic was crossed over. Adherence was assessed by liquid chromatographic assay for NVP of cord blood. Regarding uptake, 1524 pregnant women were offered participation, and 1025 (67%) accepted. Of 694 women offered enrollment in the universal strategy, 496 (71%) accepted; of 830 women offered enrollment in the targeted strategy, 529 (64%) accepted (p < .01). Uptake was similar at both clinics for the universal strategy: 250 of 339 (74%) at clinic A and 246 of 355 (69%) at clinic B (p [H11505] .2), but differed significantly between clinics for the targeted strategy: 229 of 316 (72%) at clinic A and 300 of 514 (58%) at clinic B (RR, 1.51; 95% CI, 1.23, 1.86). Increased uptake correlated with having been offered the universal rather than the targeted strategy (AOR, 1.5; 95% CI, 1.1, 2.1), attendance at clinic A (AOR, 1.4; 95% CI, 1.01, 2.0), and maternal report of a prior fetal or infant death (AOR, 1.6; 95% CI, 1.1, 2.5). Regarding adherence, in the universal strategy, 40 of 103 women (39%) were nonadherent compared with 25 of 98 women (26%) in the targeted strategy (RR, 1

  20. Analysis and validation of a quasi-dynamic model for a solar collector field with flat plate collectors and parabolic trough collectors in series for district heating

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2018-01-01

    A quasi-dynamic TRNSYS simulation model for a solar collector field with flat plate collectors and parabolic trough collectors in series was described and validated. A simplified method was implemented in TRNSYS in order to carry out long-term energy production analyses of the whole solar heating...... performance of the hybrid solar district heating plants is also presented. The measured and simulated results show that the integration of parabolic trough collectors in solar district heating plants can guarantee that the system produces hot water with relatively constant outlet temperature. The daily energy...... plant. The advantages of the model include faster computation with fewer resources, flexibility of different collector types in solar heating plant configuration and satisfactory accuracy in both dynamic and long-term analyses. In situ measurements were taken from a pilot solar heating plant with 5960 m...

  1. Optimization of a Solar-Driven Trigeneration System with Nanofluid-Based Parabolic Trough Collectors

    Directory of Open Access Journals (Sweden)

    Evangelos Bellos

    2017-06-01

    Full Text Available The objective of this work was to optimize and to evaluate a solar-driven trigeneration system which operates with nanofluid-based parabolic trough collectors. The trigeneration system includes an organic Rankine cycle (ORC and an absorption heat pump operating with LiBr-H2O which is powered by the rejected heat of the ORC. Toluene, n-octane, Octamethyltrisiloxane (MDM and cyclohexane are the examined working fluids in the ORC. The use of CuO and Al2O3 nanoparticles in the Syltherm 800 (base fluid is investigated in the solar field loop. The analysis is performed with Engineering Equation Solver (EES under steady state conditions in order to give the emphasis in the exergetic optimization of the system. Except for the different working fluid investigation, the system is optimized by examining three basic operating parameters in all the cases. The pressure in the turbine inlet, the temperature in the ORC condenser and the nanofluid concentration are the optimization variables. According to the final results, the combination of toluene in the ORC with the CuO nanofluid is the optimum choice. The global maximum exergetic efficiency is 24.66% with pressure ratio is equal to 0.7605, heat rejection temperature 113.7 °C and CuO concentration 4.35%.

  2. The Pyramid Trough Wetland: environmental and biological diversity in a newly created Antarctic protected area.

    Science.gov (United States)

    Jungblut, Anne D; Wood, Susanna A; Hawes, Ian; Webster-Brown, Jenny; Harris, Colin

    2012-11-01

    The Pyramid Trough (Lat 78°S) has recently gained protection under the Antarctic Treaty system, owing to its wetland values. Here, we describe the microbial diversity of this system, with emphasis on cyanobacteria, and evaluate environment-biota relationships. Geochemistry separates ponds along hydrological gradients receiving recent inflows of dilute meltwater, from a second group that is rarely inundated and where chemistry is dominated by evaporation. Cyanobacteria-based microbial mats dominated the biota throughout. Mats were characterized by light-microscopy, pigment analysis, automated ribosomal intergenic spacer analysis and 16S rRNA gene clone libraries. A total of 17 morphotypes and 21 ribotypes were identified, mostly Oscillatoriales and several taxa that are usually rare in continental Antarctica, including Chroococcales and scytomin-rich Calothrix/Dichothrix, were abundant. There was a general decline in cyanobacterial diversity with increasing conductivity, but weak support for either differences in community composition between the two groups of ponds or sorting of taxa along the hydrological gradients with the pond groups. This implies a broad environmental tolerance and a prevalence of neutral assembly mechanisms in cyanobacterial communities of Antarctic wetland ecosystems. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  3. Reducing the Cost of Thermal Energy Storage for Parabolic Trough Solar Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Gawlik, Keith

    2013-06-25

    Thermal energy storage systems using phase change materials were evaluated for trough systems that use oil, steam, and high temperature salts as heat transfer fluids. A variety of eutectic salts and metal alloys were considered as phase change materials in a cascaded arrangement. Literature values of specific heat, latent heat, density, and other thermophysical properties were used in initial analyses. Testing laboratories were contracted to measure properties for candidate materials for comparison to the literature and for updating the models. A TRNSYS model from Phase 1 was further developed for optimizing the system, including a novel control algorithm. A concept for increasing the bulk thermal conductivity of the phase change system was developed using expanded metal sheets. Outside companies were contracted to design and cost systems using platecoil heat exchangers immersed in the phase change material. Laboratory evaluations of the one-dimensional and three-dimensional behavior of expanded metal sheets in a low conductivity medium were used to optimize the amount of thermal conductivity enhancement. The thermal energy storage systems were compared to baseline conventional systems. The best phase change system found in this project, which was for the high temperature plant, had a projected cost of $25.2 per kWhth, The best system also had a cost that was similar to the base case, a direct two-tank molten salt system.

  4. Comparative analyses of the bacterial community of hydrothermal deposits and seafloor sediments across Okinawa Trough

    Science.gov (United States)

    Wang, Long; Yu, Min; Liu, Yan; Liu, Jiwen; Wu, Yonghua; Li, Li; Liu, Jihua; Wang, Min; Zhang, Xiao-Hua

    2018-04-01

    As an ideal place to study back-arc basins and hydrothermal eco-system, Okinawa Trough has attracted the interests of scientists for decades. However, there are still no in-depth studies targeting the bacterial community of the seafloor sediments and hydrothermal deposits in Okinawa Trough. In the present study, we reported the bacterial community of the surface deposits of a newly found hydrothermal field in the southern Okinawa Trough, and the horizontal and vertical variation of bacterial communities in the sediments of the northern Okinawa Trough. The hydrothermal deposits had a relatively high 16S rRNA gene abundance but low bacterial richness and diversity. Epsilonproteobacteria and Bacteroidetes were predominant in hydrothermal deposits whereas Deltaproteobacteria, Gammaproteobacteria and Chloroflexi were abundant across all samples. The bacterial distribution in the seafloor of Okinawa Trough was significantly correlated to the content of total nitrogen, and had consistent relationship with total carbon. Gradual changes of sulfur-oxidizing bacteria were found with the distance away from hydrothermal fields, while the hydrothermal activity did not influence the distribution of the major clades of sulfate-reducing bacteria. Higher abundance of the sulfur cycle related genes (aprA and dsrB), and lower abundance of the bacterial ammonia-oxidizing related gene (amoA) were quantified in hydrothermal deposits. In addition, the present study also compared the inter-field variation of Epsilonproteobacteria among multi-types of hydrothermal vents, revealing that the proportion and diversity of this clade were quite various.

  5. The equatorward wall of the subauroral trough in the afternoon/evening sector

    Directory of Open Access Journals (Sweden)

    G. W. Prölss

    2007-03-01

    Full Text Available Although ionospheric troughs are a very important feature of the subauroral ionosphere, many of their properties remain incompletely documented and understood. Here Dynamics Explorer-2 satellite data are used to investigate one specific part of this complex phenomenon, namely its equatorward wall. We find that in the afternoon/evening sector of the Northern Hemisphere the location of this density drop depends primarily on the level of geomagnetic activity and magnetic local time. Longitudinal variations are only of secondary importance. A formula is derived which summarizes these variations. The magnitude of the density drop in the trough wall depends primarily on altitude and longitude, and to a lesser degree on local time and geomagnetic activity. These variations are also described quantitatively. Using a superposed epoch type of averaging procedure, a mean latitudinal profile of the trough wall is derived. No anomalous increase in the density at the equatorward edge of the trough is observed. There is, however, a significant increase in the electron temperature at the location of the density drop. Our results are important for the empirical description and numerical simulation of ionospheric troughs. They also may be used to define the boundary between middle and subauroral latitudes.

  6. Outlet glacier trough size-drainage area relationships, Fiordland, New Zealand

    Science.gov (United States)

    Augustinus, Paul C.

    1992-03-01

    This paper examines relationships between the area supplying ice to fiord troughs and various measures of fiord size such as depth. width and length in Fiordland, New Zealand. The size of the outlet troughs was found to be adjusted to the discharge of ice, following a similar relationship to that encountered with fiords developed under essentially cold-based ice sheets in British Columbia. However, the Fiordland outlet troughs were substantially shorter and shallower than their counterparts in British Columbia. This difference may reflect contrast in mode of erosion in each case, although the major dimensions of the fiords undoubtedly reflect the controlling influence of the pre-glacial lanscape upon which ice-caps were superimposed with their rediating outlet glaciers.

  7. A vacuum tube vee-trough collector for solar heating and air conditioning applications

    Science.gov (United States)

    Selcuk, M. K.

    1978-01-01

    An analysis is conducted of the performance of a vee-trough vacuum tube collector proposed for use in solar heating and cooling applications. The vee-trough reflector is a triangular sectioned, flat surfaced reflector, whose axis is laid in the East-West direction. A vacuum tube receiver placed at the bottom of the vee-trough collects solar heat most efficiently since convection is completely eliminated. Radiation losses are reduced by use of selective coatings on the absorber. Owing to its high temperature capabilities (300-400 F), the proposed scheme could also be used for power generation applications in combination with an organic Rankine conversion system. It is especially recommended for unattended pumping stations since the reflectors only require reversal once every six months.

  8. Class II Eplet Mismatch Modulates Tacrolimus Trough Levels Required to Prevent Donor-Specific Antibody Development.

    Science.gov (United States)

    Wiebe, Chris; Rush, David N; Nevins, Thomas E; Birk, Patricia E; Blydt-Hansen, Tom; Gibson, Ian W; Goldberg, Aviva; Ho, Julie; Karpinski, Martin; Pochinco, Denise; Sharma, Atul; Storsley, Leroy; Matas, Arthur J; Nickerson, Peter W

    2017-11-01

    Despite more than two decades of use, the optimal maintenance dose of tacrolimus for kidney transplant recipients is unknown. We hypothesized that HLA class II de novo donor-specific antibody ( dn DSA) development correlates with tacrolimus trough levels and the recipient's individualized alloimmune risk determined by HLA-DR/DQ epitope mismatch. A cohort of 596 renal transplant recipients with 50,011 serial tacrolimus trough levels had HLA-DR/DQ eplet mismatch determined using HLAMatchmaker software. We analyzed the frequency of tacrolimus trough levels below a series of thresholds mismatch. HLA-DR/DQ eplet mismatch was a significant multivariate predictor of dn DSA development. Recipients treated with a cyclosporin regimen had a 2.7-fold higher incidence of dn DSA development than recipients on a tacrolimus regimen. Recipients treated with tacrolimus who developed HLA-DR/DQ dn DSA had a higher proportion of tacrolimus trough levels mismatch. Mean tacrolimus trough levels in the 6 months before dn DSA development were significantly lower than the levels >6 months before dn DSA development in the same patients. Recipients with a high-risk HLA eplet mismatch score were less likely to tolerate low tacrolimus levels without developing dn DSA. We conclude that HLA-DR/DQ eplet mismatch and tacrolimus trough levels are independent predictors of dn DSA development. Recipients with high HLA alloimmune risk should not target tacrolimus levels <5 ng/ml unless essential, and monitoring for dn DSA may be advisable in this setting. Copyright © 2017 by the American Society of Nephrology.

  9. Mineralogy and geological significance of hydrothermal deposits from the Okinawa Trough

    Science.gov (United States)

    Zhang, Xia; Zhai, Shikui; Yu, Zenghui; Wang, Shujie; Cai, Zongwei

    2018-04-01

    The study of hydrothermal deposits in the Okinawa Trough can help us to uncover the hydrothermal mineralization characteristics in the back-arc basin during the early expanding stage. Mineralogy and geological significance of hydrothermal deposits from both the middle and southern trough are studied in this paper. First of all, using optical microscope to confirm the mineral compositions, characteristics of crystal shape, paragenetic relationship and minerals crystallization order. Then the minerals chemical composition were analyzed in virtue of electron microprobe. On these basis, the paragenetic sequence and the mineralization characteristics of the hydrothermal deposits were discussed. The results show that the hydrothermal deposit from the mid-Okinawa Trough belongs to Zn-Cu-rich type, consisting dominantly of sulfide minerals such as sphalerite, chalcopyrite, pyrite, etc. The minerals crystallization order is first generation pyrite(PyI)-sphalerite-chalcopyrite-galena-second generation pyrite(PyII)-amorphous silica. While the deposit from the southern Okinawa Trough is Ba-Zn-Pb-rich type mainly composing of barite, sphalerite, galena, etc. The minerals crystallization order is barite-pyrite-sphalerite-tetrahedrite-galena-chalcopyrite-amorphous silica. Hydrothermal fluid temperature in the mid-Okinawa Trough undergoes a process from high to low, which is high up to 350 °C in the early stage, but decreasing gradually with the evolution of hydrothermal fluid. On the contrary, the hydrothermal activity in the southern Okinawa Trough is low temperature dominated, but the mineralization environment is unstable and the fluid temperature changes drastically during the period of hydrothermal activity.

  10. Improving the concentration ratio of parabolic troughs using a second-stage flat mirror

    International Nuclear Information System (INIS)

    Rodriguez-Sanchez, David; Rosengarten, Gary

    2015-01-01

    Highlights: • A secondary flat reflector is added to commercial parabolic troughs. • Theoretical derivations and ray tracing used to size and position the absorber. • Concentration ratio increases up to 80% can be achieved for current collectors. • New flux distributions around the absorber are calculated. • The use of flat secondary reflector will increase the plant efficiency. - Abstract: Increasing the concentration ratio of parabolic troughs is one of the challenges to make this technology economically competitive against fossil fuels. Parabolic troughs with large concentration ratios face several problems such as difficulty capturing all the solar direct radiation and structural issues associated with thermal expansions and wind resistance amongst others. For larger mirrors it may be necessary to use a bigger absorber in order to capture all the radiation, thus increasing the thermal losses. A second stage reflector helps to increase the concentration ratio without increasing the primary mirror size. In this work, a theoretical analysis of a parabolic trough with a secondary flat reflector is developed and ray tracing is conducted in order to validate the equations obtained. A flat reflector will have a minimal economic impact in the cost of a parabolic trough and it allows larger concentration ratios for identical primary mirror areas compared to a standard parabolic trough. Increases of concentration ratio up to 80% are observed when a secondary flat reflector is inserted in a commercial system, while the shadow area introduced in the primary mirror is usually less than 15% of the primary mirror area. The increase in pumping power is offset by the increase in system efficiency.

  11. Tracking local control of a parabolic trough collector; Control local de seguimiento cilindro parabolico ACE20

    Energy Technology Data Exchange (ETDEWEB)

    Ajona, J.I.; Alberdi, J.; Gamero, E.; Blanco, J.

    1992-07-01

    In the local control, the sun position related to the trough collector is measured by two photo-resistors. The provided electronic signal is then compared with reference levels in order to get a set of B logical signals which form a byte. This byte and the commands issued by a programmable controller are connected to the inputs of o P.R.O.M. memory which is programmed with the logical equations of the control system. The memory output lines give the control command of the parabolic trough collector motor. (Author)

  12. Tridimensional analysis of gravitational and magnetic fields of Terek-Caspian trough

    Science.gov (United States)

    Kerimov, I. A.; Abubakarova, E. A.; Badaev, S. V.

    2017-10-01

    The results of the tridimensional analysis of the gravitational and magnetic fields of the Terek-Caspian trough are presented in this article. Various transformations of the region’s gravitational and magnetic fields (separation into components, calculation of higher derivatives, measurement of statistical characteristics, tracing of the anomaly axes, etc.) were performed. The morphology of the gravitational and magnetic fields was investigated, the characteristics of the anomalous geophysical fields were outlined and the relationship between various field characteristics and the features of the fault-block tectonics of the trough was analyzed.

  13. Analytical Approach Treating Three-Dimensional Geometrical Effects of Parabolic Trough Collectors: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Binotti, M.; Zhu, G.; Gray, A.; Manzollini, G.

    2012-04-01

    An analytical approach, as an extension of one newly developed method -- First-principle OPTical Intercept Calculation (FirstOPTIC) -- is proposed to treat the geometrical impact of three-dimensional (3-D) effects on parabolic trough optical performance. The mathematical steps of this analytical approach are presented and implemented numerically as part of the suite of FirstOPTIC code. In addition, the new code has been carefully validated against ray-tracing simulation results and available numerical solutions. This new analytical approach to treating 3-D effects will facilitate further understanding and analysis of the optical performance of trough collectors as a function of incidence angle.

  14. Many play concepts seen over wide area in Erris, Slyne troughs off Ireland

    International Nuclear Information System (INIS)

    Murphy, N.J.; Croker, P.F.

    1992-01-01

    This paper reports that the Erris and Slyne troughs are underexplored Mesozoic sedimentary basins off Ireland's northwest coast. The Irish Minister for Energy announced on Apr. 19, 1991, a frontier acreage licensing round of 128 blocks covering 29,000 sq km in these basins and the adjacent Rockall trough. Closing date for the round is June 30, 1993, set to allow two seasons for the acquisition of new geophysical and geological data over the area. Ireland has recently announced a new petroleum taxation regime. Revised licensing terms, which will acknowledge the specific circumstances of frontier acreage, will be announced

  15. Effect of system variables involved in packed column SFC of nevirapine as model analyte using response surface methodology: application to retention thermodynamics, solute transfer kinetic study and binary diffusion coefficient determination.

    Science.gov (United States)

    Kaul, Neerej; Agrawal, Himani; Paradkar, A R; Mahadik, K R

    2005-08-31

    A multifactor optimization technique is successfully applied to study the effect of simultaneously varying the system variables on feasibility of nevirapine analysis by packed column supercritical fluid chromatography (PC-SFC). The optimal conditions were determined with the aid of the response surface methodology using 3(3) factorial designs. The method is based on methanol-modified carbon dioxide as the mobile phase at flow rate of 3.0 ml/min with elution through a JASCO Finepak SIL-5, [C18 (5-micron, 25 cm x 4.6 mm, i.d.)] column using photodiode array detection. The method has been successfully used to analyze commercial solid dosage form to assess the chromatographic performance of SFC system. The present work briefs the thermodynamic applications of PC-SFC with an emphasis on the results of nevirapine. The foremost of such applications is the determination of solute diffusion coefficient in supercritical mobile phase by Taylor-Aris peak broadening technique.

  16. Higher infliximab trough levels are associated with perianal fistula healing in patients with Crohn's disease.

    Science.gov (United States)

    Yarur, A J; Kanagala, V; Stein, D J; Czul, F; Quintero, M A; Agrawal, D; Patel, A; Best, K; Fox, C; Idstein, K; Abreu, M T

    2017-04-01

    Infliximab has been found to be efficacious in the treatment of fistulas in the setting of Crohn's disease, even though some patients do not benefit from therapy. To assess the correlation between perianal fistula healing and trough levels of infliximab. In this cross-sectional study, we identified patients with Crohn's disease who had perianal fistulas and were treated with infliximab for at least 24 weeks. We excluded patients who underwent a faecal diversion procedure or proctectomy. Predictive variables included demographics, disease phenotype, disease activity, infliximab levels, anti-infliximab antibodies. The primary outcome was fistula healing defined as the absence of drainage. The secondary outcome was complete fistula closure and mucosal healing. 117 patients were included. Patients with fistula healing had significantly higher median serum infliximab levels when compared to those with active fistulas [15.8 vs. 4.4 μg/mL, respectively (P infliximab levels. The AUC for the association between fistula healing and infliximab levels was 0.82 (P infliximab levels and fistula closure was 0.69 (P = 0.014). Patients with anti-infliximab antibodies had a lower chance of achieving fistula healing (OR: 0.04 [95%CI: 0.005-0.3], P infliximab levels and rates of fistula healing. Achieving infliximab levels ≥10.1 mcg/mL in patients with Crohn's disease and perianal fistulas may improve outcomes as part of a treat-to-target strategy. © 2017 John Wiley & Sons Ltd.

  17. Upstream sediment input effects on experimental dune trough scour in sediment mixtures

    NARCIS (Netherlands)

    Kleinhans, M.G.

    2005-01-01

    Understanding causes of dune irregularity, especially dune trough scour, is important for the modeling of vertical sorting of sediment mixtures in morphological models of rivers with sediment mixtures. Sediment in dunes is generally sorted in a fining-upward manner, which affects the sediment

  18. A Study Investigating the Association of Dermatological and Infusion Reactions to Infliximab and Infliximab Trough Levels

    Directory of Open Access Journals (Sweden)

    Vivian Wai-Mei Huang

    2015-01-01

    Full Text Available BACKGROUND: Although infliximab is an effective therapy for inflammatory bowel disease (IBD, it is associated with dermatological events and infusion reactions. It is not known whether a relationship between these adverse events (AEs and infliximab trough levels (ITLs exists.

  19. Basinal Structure Of Yola Arm Of The Upper Benue Trough Nigeria ...

    African Journals Online (AJOL)

    Aeromagnetic data interpretation of the Yola arm of the Upper Benue Trough has previously been carried out. However, no detail modeling of the Crustal Structures has been undertaken. Two composite reduced Aeromagnetic maps on a scale of 1:250,000 were digitized and processed using computer techniques.

  20. Altitude variation of the plasmapause signature in the main ionospheric trough

    Czech Academy of Sciences Publication Activity Database

    Grebowsky, J. M.; Benson, R. F.; Webb, P. A.; Truhlík, Vladimír; Bilitza, D.

    2009-01-01

    Roč. 71, č. 16 (2009), s. 1669-1676 ISSN 1364-6826 R&D Projects: GA AV ČR IAA300420603 Institutional research plan: CEZ:AV0Z30420517 Keywords : Plasmapause * Ionosphere * Midlatitude Trough Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.643, year: 2009

  1. Numerical simulation of tropical-temperate troughs over Southern Africa using the CSU RAMS model

    CSIR Research Space (South Africa)

    Van den Heever, SC

    1997-08-01

    Full Text Available ) and the wet (1981) late summer case studies has been examined. Model simulations reveal that the tropical-temperate troughs form when an upper westerly wave coincides with an easterly, wave or depression in lower levels. These systems occur preferentially over...

  2. The Neogene-Quaternary geodynamic evolution of the central Calabrian Arc: A case study from the western Catanzaro Trough basin

    Science.gov (United States)

    Brutto, F.; Muto, F.; Loreto, M. F.; Paola, N. De; Tripodi, V.; Critelli, S.; Facchin, L.

    2016-12-01

    The Catanzaro Trough is a Neogene-Quaternary basin developed in the central Calabrian Arc, between the Serre and the Sila Massifs, and filled by up to 2000 m of continental to marine deposits. It extends from the Sant'Eufemia Basin (SE Tyrrhenian Sea), offshore, to the Catanzaro Basin, onshore. Here, onshore structural data have been integrated with structural features interpreted using marine geophysical data to infer the main tectonic processes that have controlled the geodynamic evolution of the western portion of the Catanzaro Trough, since Upper Miocene to present. The data show a complex tectonostratigraphic architecture of the basin, which is mainly controlled by the activity of NW-SE and NE-SW trending fault systems. In particular, during late Miocene, the NW-SE oriented faults system was characterized by left lateral kinematics. The same structural regime produces secondary fault systems represented by E-W and NE-SW oriented faults. The ca. E-W lineaments show extensional kinematics, which may have played an important role during the opening of the WNW-ESE paleo-strait; whereas the NE-SW oriented system represents the conjugate faults of the NW-SE oriented structural system, showing a right lateral component of motion. During the Piacenzian-Lower Pleistocene, structural field and geophysical data show a switch from left-lateral to right-lateral kinematics of the NW-SE oriented faults, due to a change of the stress field. This new structural regime influenced the kinematics of the NE-SW faults system, which registered left lateral movement. Since Middle Pleistocene, the study area experienced an extensional phase, WNW-ESE oriented, controlled mainly by NE-SW and, subordinately, N-S oriented normal faults. This type of faulting splits obliquely the western Catanzaro Trough, producing up-faulted and down-faulted blocks, arranged as graben-type system (i.e Lamezia Basin). The multidisciplinary approach adopted, allowed us to constrain the structural setting of

  3. Biological and geological characteristics of the R1 and R2 coral mounds, Rockall Trough, west of Ireland.

    Science.gov (United States)

    Unnithan, V.; Grehan, A.; van Weering, T.; Olu-Leroy, K.

    2003-04-01

    The carbonate mounds discovered in the mid-1990s on the Irish Continental Margin are unique. It is not only their size (up to 300 m in height and 2-3 km in diameter), distribution (along the margins of the Porcupine Seabight and Rockall Trough), abundance (> 250 individual mounds) but also their association with deep-water coral species that has generated a great deal of interest in the scientific community. During the past 10 years a number of European Union funded projects concentrated their efforts on studying these deep-sea features. However, there is still a great deal to be learnt regarding mound structure, dynamics and genesis. The basic question why and how carbonate mounds are formed is still largely unanswered. The CARACOLE (CARbonate And COLD water Ecosystems) Cruise in August 2001, was an Irish-French-EU inter-disciplinary co-operation program with participation of ACES, ECOMOUND and GEOMOUND related scientists from Germany, The Netherlands and Belgium to study carbonate mounds and deep-coral reefs in the Porcupine Seabight and Rockall Trough, west of Ireland. The IFREMER led cruise aboard the French Research Vessel Atalante deployed the 'state of the art' remotely operated vehicle, Victor 6000 at a total of 5 mound locations selected on the basis of previous extensive seismic, acoustic and bottom sampling studies, mainly carried out by RV 'Pelagia' of the Royal NIOZ. High-resolution geo-referenced video and digital still photography was used for detailed observation and mapping. This poster presents preliminary results and work in progress from the R1 and R2 Rockall Trough mound sites based on video and bathymetric analysis carried out by the authors in March 2002 at IFREMER. The focus of the analysis was two fold: 1) Biological, encompassing the identification and mapping of coral habitats and associated species, and 2) geological which includes mapping of the morphology and nature (character) of the seabed. From the observations and analysis

  4. The influence of a subduction component on magmatism in the Okinawa Trough: Evidence from thorium and related trace element ratios

    Science.gov (United States)

    Guo, Kun; Zeng, Zhi-Gang; Chen, Shuai; Zhang, Yu-Xiang; Qi, Hai-Yan; Ma, Yao

    2017-09-01

    The Okinawa Trough (OT) is a back-arc, initial continental marginal sea basin located behind the Ryukyu Arc-Trench System. Formation and evolution of the OT have been intimately related to subduction of the Philippine Sea Plate (PSP) since the late Miocene; thus, the magma source of the trough has been affected by subduction components, as in the case of other active back-arc basins, including the Lau Basin (LB) and Mariana Trough (MT). We review all the available geochemical data relating to basaltic lavas from the OT and the middle Ryukyu Arc (RA) in this paper in order to determine the influence of the subduction components on the formation of arc and back-arc magmas within this subduction system. The results of this study reveal that the abundances of Th in OT basalts (OTBs) are higher than that in LB (LBBs) and MT basalts (MTBs) due to the mixing of subducted sediments and EMI-like enriched materials. The geochemical characteristics of Th and other trace element ratios indicate that the OTB originated from a more enriched mantle source (compared to N-mid-ocean ridge basalt, N-MORB) and was augmented by subducted sediments. Data show that the magma sources of the south OT (SOT) and middle Ryukyu Arc (MRA) basalts were principally influenced by subducted aqueous fluids and bulk sediments, which were potentially added into magma sources by accretion and underplating. At the same time, the magma sources of the middle OT (MOT) and Kobi-syo and Sekibi-Syo (KBS+SBS) basalts were impacted by subducted aqueous fluids from both altered oceanic crust (AOC) and sediment. The variable geochemical characteristics of these basalts are due to different Wadati-Benioff depths and tectonic environments of formation, while the addition of subducted bulk sediment to SOT and MRA basalts may be due to accretion and underplating, and subsequent to form mélange formation, which would occur partial melting after aqueous fluids are added. The addition of AOC and sediment aqueous fluid

  5. Understanding the Compositional Variability of the Major Components of Hydrothermal Plumes in the Okinawa Trough

    Directory of Open Access Journals (Sweden)

    Zhigang Zeng

    2018-01-01

    Full Text Available Studies of the major components of hydrothermal plumes in seafloor hydrothermal fields are critical for an improved understanding of biogeochemical cycles and the large-scale distribution of elements in the submarine environment. The composition of major components in hydrothermal plume water column samples from 25 stations has been investigated in the middle and southern Okinawa Trough. The physical and chemical properties of hydrothermal plume water in the Okinawa Trough have been affected by input of the Kuroshio current, and its influence on hydrothermal plume water from the southern Okinawa Trough to the middle Okinawa Trough is reduced. The anomalous layers of seawater in the hydrothermal plume water columns have higher K+, Ca2+, Mn2+, B3+, Ca2+/SO42-, and Mn2+/Mg2+ ratios and higher optical anomalies than other layers. The Mg2+, SO42-, Mg2+/Ca2+, and SO42-/Mn2+ ratios of the anomalous layers are lower than other layers in the hydrothermal plume water columns and are consistent with concentrations in hydrothermal vent fluids in the Okinawa Trough. This suggests that the chemical variations of hydrothermal plumes in the Tangyin hydrothermal field, like other hydrothermal fields, result in the discharge of high K+, Ca2+, and B3+ and low Mg2+ and SO42- fluid. Furthermore, element ratios (e.g., Sr2+/Ca2+, Ca2+/Cl− in hydrothermal plume water columns were found to be similar to those in average seawater, indicating that Sr2+/Ca2+ and Ca2+/Cl− ratios of hydrothermal plumes might be useful proxies for chemical properties of seawater. The hydrothermal K+, Ca2+, Mn2+, and B3+ flux to seawater in the Okinawa Trough is about 2.62–873, 1.04–326, 1.30–76.4, and 0.293–34.7 × 106 kg per year, respectively. The heat flux is about 0.159–1,973 × 105 W, which means that roughly 0.0006% of ocean heat is supplied by seafloor hydrothermal plumes in the Okinawa Trough.

  6. Radiometric evidence of Middle Devonian inversion of the Hill End Trough, northeast Lachlan Fold Belt

    International Nuclear Information System (INIS)

    Pakham, G.H.

    1999-01-01

    The publication of a new geological time-scale by the Australian Geological Survey Organisation and radiometric dates from the Hill End goldfield have prompted the re-examination of the timing of deformation of the Hill End Trough to determine whether it occurred in Middle Devonian or Early Carboniferous time. Palaeontological evidence from the western trough margin and the Capertee High dates the end of deposition in the trough as late Emsian or early Eifelian (385-382 Ma). After a mid-Devonian hiatus of at least 15 million years, paralic sedimentation commenced on the Molong and Capertee Highs in late Frasnian or early Famennian time (367-363 Ma). No Upper Devonian sedimentary formations occur in the Hill End Trough. Structural relationships indicate that the oldest mineral veins at Hill End preceded cleavage formation in the deformed trough sedimentary rocks. Early vein muscovites have Middle Devonian 40 Ar/ 39 Ar dates of 380-370 Ma. Regional metamorphic biotites from Hill End have well constrained 40 Ar/ 39 Ar closing ages of 360-358 Ma (mid-Famennian). The metamorphic (thermal) maximum which outlasted penetrative deformation. is estimated here by modelling to have been about 370 Ma (latest Givetian). This clearly places the earlier main deformation in the Middle Devonian. Deformation probably began by terminating trough deposition in latest Emsian to early Eifelian time and ended in early Givetian time at about 375 Ma ago. Published pressure and temperature data from the Hill End goldfield suggest that deformation thickened the 6 km sediment column to around 11 km. The thermal model suggests there was post-deformation erosion of about 4km and little if any further erosion occurred during Late Devonian to Early Carboniferous time. The shortening accompanying the inversion of the northern Hill End Trough may have been taken up in the region to the south, both east and west of the Copperhannia Thrust, and east of the southern termination of the Capertee High

  7. Decline of a Hydrothermal Vent Field - Escanaba Trough 12 Years Later

    Science.gov (United States)

    Zierenberg, R. A.; Clague, D. A.; Davis, A. S.; Lilley, M. D.; McClain, J. S.; Olson, E. S.; Ross, S. L.; Von Damm, K. L.

    2001-12-01

    Hydrothermal venting was discovered in Escanaba Trough, the southern sediment-covered portion of the Gorda Ridge, in 1988. Large pyrrhotite-rich massive sulfide mounds are abundant at each of the volcanic/intrusive centers that have been investigated in Escanaba Trough, but the only area of known hydrothermal venting is the NESCA site along the ridge axis at 41\\deg N. Hydrothermal fluids venting at 217\\deg C and 108\\deg C were sampled in 1988 on two sulfide mounds separated by about 275 m. The end-member fluid compositions were indistinguishable within analytical errors. Several sulfide mounds were observed in 1988 which had diffusely venting low temperature (holes were drilled in the NESCA area in 1996 on ODP Leg 169, including Hole 1036I that penetrated to basaltic basement at 405 m below sea floor (mbsf). Surveys of the area using the drill string camera located only one area of active venting at the same mound where 217\\deg C vent fluids were sampled from two active vents in 1988. Drill hole 1036A was spudded between the two active vents on this sulfide mound (approximately 4 and 8 m away) and penetrated to 115 mbsf. The NESCA site was revisited in 2000 using MBARI's R/V Western Flyer and ROV Tiburon. The hydrothermal vents appeared essentially identical to observations made from the drill string camera in 1996 despite the presence of a drill hole within meters of the two vents. The maximum vent temperature measured in 2000 was 212\\deg C. Fluid samples have major element and isotopic compositions very similar to those collected in 1988. The vent fluids have higher methane ( ~19 mmol/kg) than those from the geologically similar Middle Valley vent field, but lower values than those at Guaymas Basin. Drill hole 1036A was weakly venting, but the diffuse hydrothermal fluids could not be sampled with the equipment available. The walls of the drill hole were colonized by palm worms, limpets, and snails. Four other drill holes showed no hydrothermal flow nor

  8. Troughs in Ice Sheets and Other Icy Deposits on Mars: Analysis of Their Radiative Balance

    Science.gov (United States)

    Fountain, A.; Kargel, J.; Lewis, K.; MacAyeal, D.; Pfeffer, T.; Zwally, H. J.

    2000-01-01

    It has long been known that groove-like structures in glaciers and ice sheets can trap more incoming solar radiation than is the case for a 'normal' flat, smooth surface. In this presentation, we shall describe the radiative regimes of typical scarps and troughs on icy surfaces of Mars, and suggest how these features originate and evolve through time. The basis of our analysis is the radiation balance model presented by Pfeffer and Bretherton. Their model considers the visible band radiation regime of a V-shaped groove on a terrestrial ice surface, and shows that absorbed energy can be enhanced by up to 50 percent for grooves with small opening angles and with typical polar values of the solar zenith angle. Our work extends this model by considering: (a) departures from V-shaped geometry, (b) both englacial and surficial dust and debris, and (c) the infrared spectrum. We apply the extended model to various features on the Martian surface, including the spiral-like scarps on the Northern and Southern ice sheets, the large-scale chasms (e.g., Chasm Borealis), and groove-like lineations on valley floors thought to be filled with mixtures of dust and icy substances. In conjunction with study of valley-closure experiments, we suggest that spiral-like scarps and chasms are stable features of the Martian climate regime. We also suggest that further study of scarps and chasms may shed light on the composition (i.e., relative proportions of water ice, carbon-dioxide ice and dust) of the Martian ice sheets and valley fills.

  9. Extremely magnetized abyssal lavas erupted in active back-arc of the Okinawa Trough

    Science.gov (United States)

    Fujii, M.; Sato, H.; Okino, K.

    2017-12-01

    Although high-amplitude of marine magnetic anomalies have been utilized for understanding for seafloor dynamics, the causal link between intensity of natural remanent magnetization and physical and chemical processes of extrusive rocks are still unclear. In addition, we essentially lack rock magnetic data of arc-back-arc lavas, which potentially provide strong constraints for understanding time- and spatial-dependent diversity of lava magnetization including mid-ocean ridge basalts. Here, we present new rock magnetic data of strongly magnetized basaltic rocks, which rank among the most magnetized in known oceanic basaltic rocks, from active back-arc region of the Okinawa Trough. We analyzed 27 non-oxidized (fresh) basaltic rock samples obtained from the active back-arc volcanoes, located at the segment boundary along back-arc rift. Their natural remanent magnetization ranges 7 A/m to >200 A/m, and has clear nonlinear relationship with both magnetic hysteresis signatures and titanomagnetite amount. The strongly magnetized lavas show large contribution of appropriate amount of SD titanomagnetite grains formed in proper crystal growth environments. The high-temperature thermomagnetic experiments demonstrate reversible curves in both heating and cooling with single Curie temperature. The Curie temperature shows up to 480°C for strongly magnetized lavas, which is much higher than that of mid-ocean ridge basalts mainly containing TM60, indicating that rich Fe and low Ti contents of titanomagnetite grains are main magnetic carrier. These observations clearly demonstrate that intensity of natural remanent magnetization is primarily controlled by cooling rate of lavas and ratio of Fe to Ti of titanomagnetite grains as well as bulk iron contents, with important implications towards marine magnetic anomalies and arc-back-arc volcanism.

  10. Rare gases in lavas from the ultraslow spreading Lena Trough, Arctic Ocean

    Science.gov (United States)

    Nauret, F.; Moreira, M.; Snow, J. E.

    2010-06-01

    Mid-ocean ridge basalts (MORB) from the Arctic Ocean have been much less studied than those from the Indian, Atlantic, and Pacific due to the difficulty of access related to ice cover. In 2001 and 2004 the Arctic ridges (Gakkel Ridge and Lena Trough) were intensively sampled. In this study we present the first helium, neon, and argon concentrations and isotopic ratios in a suite of samples from the ultraslow spreading Lena Trough (˜0.75 cm/yr effective full rate). Central Lena Trough (CLT) lavas display 4He/3He between 89,710 and 97,530 (R/Ra between 7.4 and 8.1), similar to the mean MORB ratio of 90,000 ± 10,000 (R/Ra = 8 ± 1). In a three neon isotope diagram, the samples fall on the MORB line, without showing any excess of nucleogenic 21Ne. The 40Ar/36Ar ratios vary from 349 to 6964. CLT samples have a typical MORB He and Ne isotopic composition. Rare gases do not indicate any mantle heterogeneities or contribution of subcontinental lithospheric mantle, although this has been suggested previously on the basis of the Sr-Nd and Pb isotopic systems. Based on noble gas systematics, a DUPAL-like anomaly is not observed in the Arctic Ocean. We propose two possible models which reconcile the rare gases with these previous studies. The first is that the Lena Trough mantle has a marble cake structure with small-scale heterogeneities (<1 km), allowing rapid diffusion and homogenization of rare gases compared to elements such as Sr, Nd, and Pb. The second model proposes that the recycled component identified by other isotopic systems was fully degassed at a recent date. It would therefore have a negligible mass budget of rare gases compared to other isotopic systems. This would suggest that the mantle enrichment beneath Lena Trough was generated by rift-forming processes and not by recycling.

  11. Geologic evolution of the Kastel trough and its implications on the Adiyaman oil fields, SE Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Coskun, Bu. (Univ. of Ankara (Turkey))

    1990-05-01

    Oil field developments of the Adiyaman area one of the main oil producing zones in southeast Turkey, have been highly influenced by geologic evolution of the Kastel trough which is situated in front of the suture zone between the Arabian and Anatolian plates. The Upper Cretaceous movements created many paleostructural trends in the Kastel trough where important dolomitic and porous reservoirs exist. The most important tectonic event, which appeared during the Upper Cretaceous movements, is the accumulation of the Kocali-Karadut ophiolitic complex, advancing from the north to the south in the Kastel trough, where heavy materials caused formation of a structural model favoring generation and migration and entrapment of oil in the reservoir rocks. Due to the presence of the Kocali-Karadut complex in the Kastel trough the following zones have been distinguished. (1) North Uplift Area. Situated under the allochthonous units, many thrust and reverse faults characterize this zone. The presence of paleohighs, where primary dolomites develop, allows the appearance of some oil fields in the region. This is the main future exploration zone in southeast Turkey. (2) Accumulation Area. Advancing from the north to the south, the allochthonous Kocali-Karadut complex filled the Kastel trough creating a deep graben whose flanks present generally normal faults. (3) Structural Belt. Important paleohighs constitute an exploration trend in this zone where dolomitic and porous carbonates contain actual oil fields. (4) South Accumulation Area. Distant from the Arabian-Anatolian suture zone, regional tectonics and sedimentology show this zone remained deeply buried during geologic time; good source rocks were deposited during the Cretaceous. (5) South Uplift Area. This area corresponds to the northern flank of the huge regional Mardin high in southeast Turkey where new oil fields have been discovered.

  12. Modeling, Simulation and Performance Evaluation of Parabolic Trough

    African Journals Online (AJOL)

    Mekuannint

    demand. Heat exchangers are used to transfer heat energy from the heat transfer fluid (HTF) to water coming from feedwater heaters. In this paper a proposed .... flexibility. The TRNSYS modeling includes the TRNSYS field model and power model. The solar field model shown in Fig. 4 includes weather data processors ...

  13. Plate boundary deformation at the latitude of the Salton Trough - northern Gulf of California (Invited)

    Science.gov (United States)

    Stock, J. M.

    2013-12-01

    Along the Pacific-North America plate boundary zone, the segment including the southern San Andreas fault to Salton Trough and northern Gulf of California basins has been transtensional throughout its evolution, based on Pacific-North America displacement vectors calculated from the global plate circuit (900 × 20 km at N54°W since 20 Ma; 460 × 20 km at N48°W since 11 Ma). Nevertheless, active seismicity and focal mechanisms show a broad zone of plate boundary deformation within which the inferred stress regime varies locally (Yang & Hauksson 2013 GJI), and fault patterns in some regions suggest ongoing tectonic rotation. Similar behavior is inferred to have occurred in this zone over most of its history. Crustal structure in this region is constrained by surface geology, geophysical experiments (e.g., the 2011 Salton Seismic Imaging Project (SSIP), USGS Imperial Valley 1979, PACE), and interdisciplinary marine and onland studies in Mexico (e.g., NARS-Baja, Cortes, and surveys by PEMEX). Magnetic data (e.g., EMAG-2) aids in the recognition of large-scale crustal provinces and fault boundaries in regions lacking detailed geophysical surveys. Consideration of existing constraints on crustal thickness and architecture, and fault and basin evolution suggests that to reconcile geological deformation with plate motion history, the following additional factors need to be taken into account. 1) Plate boundary displacement via interacting systems of rotating blocks, coeval with slip on steep strike slip faults, and possibly related to slip on low angle extensional faults (e.g, Axen & Fletcher 1998 IGR) may be typical prior to the onset of seafloor spreading. This fault style may have accommodated up to 150 km of plate motion in the Mexican Continental Borderland and north of the Vizcaino Peninsula, likely between 12 and 15 Ma, as well as explaining younger rotations adjacent to the Gulf of California and current deformation southwest of the Salton Sea. 2) Geophysical

  14. A retrospective analysis to estimate target trough concentration of vancomycin for febrile neutropenia in patients with hematological malignancy.

    Science.gov (United States)

    Suzuki, Yosuke; Tokimatsu, Issei; Morinaga, Yuko; Sato, Yuhki; Takano, Kuniko; Kohno, Kazuhiro; Ogata, Masao; Hiramatsu, Kazufumi; Itoh, Hiroki; Kadota, Jun-ichi

    2015-02-02

    The target trough concentration of vancomycin in patients with febrile neutropenia has not been reported. The aim of this study was to estimate the target trough concentration for febrile neutropenia in patients with hematological malignancy. In this retrospective, single-center, observational cohort study, 63 hospitalized patients with hematological malignancy who were treated with vancomycin for febrile neutropenia due to bacteriologically documented or presumptive Gram-positive infections were analyzed. A significant difference in the first trough concentration of vancomycin was observed between the response and non-response groups, and between the nephrotoxicity and non-nephrotoxicity groups. Multiple logistic regression analyses identified the first trough concentration as the only independent variable associated with clinical efficacy and nephrotoxicity of vancomycin. The areas under the ROC curves were 0.72 and 0.83 for clinical efficacy and nephrotoxicity, respectively. The cut-off values of the first trough concentration were 11.1 μg/ml for clinical efficacy (sensitivity 60%, specificity 87%) and 11.9 μg/ml for nephrotoxicity (sensitivity 77%, specificity 82%). These results suggest a relationship of trough vancomycin concentration with clinical efficacy and incidence of nephrotoxicity. We propose a target trough vancomycin concentration of around 11.5 μg/ml for febrile neutropenia in patients with hematological malignancy. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Durability of Stavudine, Lamivudine and Nevirapine among Advanced HIV-1 Infected Patients with/without Prior Co-administration of Rifampicin: A 144-week Prospective Study

    Directory of Open Access Journals (Sweden)

    Prasithisirikul Wisit

    2008-10-01

    Full Text Available Abstract Background To date, data on the durability of a regimen of stavudine, lamivudine and nevirapine are very limited, particularly from the resource-limited settings. Methods A prospective cohort study was conducted among 140 antiretroviral-naïve patients who were enrolled to initiate d4T, 3TC and NVP between November 2004 and March 2005. The objectives were to determine immunological and virological responses after 144 weeks of antiretroviral therapy. Seventy patients with tuberculosis also received rifampicin during the early period of antiviral treatment (TB group. Results Of all, median (IQR baseline CD4 cell count was 31 (14–79 cells/mm3; median (IQR baseline HIV-1 RNA was 433,500 (169,000–750,000 copies/mL. The average body weight was 55 kilograms. By intention-to-treat analysis at 144 weeks, the overall percentage of patients who achieved plasma HIV-1 RNA P = 0.731. Eight (5.8% patients discontinued d4T due to neuropathy and/or symptomatic lactic acidosis. Conclusion The overall durability and efficacy of antiviral response of d4T, 3TC and NVP are satisfied and they are not different between HIV-1 infected patients with and without co-administration of rifampicin due to tuberculosis. However, stavudine-related adverse effects are concerns. Trial registration ClinicalTrials.gov Identifier NCT00703898

  16. Drug-induced Liver Fibrosis: Testing Nevirapine in a Viral-like Liver Setting Using Histopathology, MALDI IMS, and Gene Expression.

    Science.gov (United States)

    Brown, H Roger; Castellino, Stephen; Groseclose, M Reid; Elangbam, Chandikumar S; Mellon-Kusibab, Kathryn; Yoon, Lawrence W; Gates, Lisa D; Krull, David L; Cariello, Neal F; Arrington-Brown, Leigh; Tillman, Tony; Fowler, Serita; Shah, Vishal; Bailey, David; Miller, Richard T

    2016-01-01

    Nevirapine (NVP) is associated with hepatotoxicity in 1-5% of patients. In rodent studies, NVP has been shown to cause hepatic enzyme induction, centrilobular hypertrophy, and skin rash in various rat strains but not liver toxicity. In an effort to understand whether NVP is metabolized differently in a transiently inflamed liver and whether a heightened immune response alters NVP-induced hepatic responses, female brown Norway rats were dosed with either vehicle or NVP alone (75 mg/kg/day for 15 days) or galactosamine alone (single intraperitoneal [ip] injection on day 7 to mimic viral hepatitis) or a combination of NVP (75/100/150 mg/kg/day for 15 days) and galactosamine (single 750 mg/kg ip on day 7). Livers were collected at necropsy for histopathology, matrix-assisted laser desorption/ionization imaging mass spectrometry and gene expression. Eight days after galactosamine, hepatic fibrosis was noted in rats dosed with the combination of NVP and galactosamine. No fibrosis occurred with NVP alone or galactosamine alone. Gene expression data suggested a viral-like response initiated by galactosamine via RNA sensors leading to apoptosis, toll-like receptor, and dendritic cell responses. These were exacerbated by NVP-induced growth factor, retinol, apoptosis, and periostin effects. This finding supports clinical reports warning against exacerbation of fibrosis by NVP in patients with hepatitis C. © The Author(s) 2016.

  17. Simultaneous quantitation of lamivudine, zidovudine and nevirapine in human plasma by liquid chromatography–tandem mass spectrometry and application to a pharmacokinetic study

    Directory of Open Access Journals (Sweden)

    Murali Krishna Matta

    2012-10-01

    Full Text Available A rapid and sensitive LC–MS/MS method for the simultaneous quantitation of lamivudine, zidovudine and nevirapine in human plasma using abacavir as internal standard has been developed and validated. The analytes and IS were extracted from plasma by solid phase extraction using Oasis HLB cartridges and separated on a Hypurity Advance C18 column using a mixture of acetonitrile:0.1% formic acid (76:24, v/v at a flow rate of 0.8 mL/min. Detection involved an API-4000 LC–MS/MS with electrospray ionization in the positive ion mode and multiple-reaction monitoring for analysis. The method was validated according to FDA guidelines and shown to provide intra- and inter-day precision and accuracy within acceptable limits in a run time of only 3.5 min. The method was successfully applied to a pharmacokinetic study involving a single oral administration of a combination tablet to human male volunteers.

  18. Mortality and virologic outcomes after access to antiretroviral therapy among a cohort of HIV-infected women who received single-dose nevirapine in Lusaka, Zambia.

    Science.gov (United States)

    Kuhn, Louise; Semrau, Katherine; Ramachandran, Shobana; Sinkala, Moses; Scott, Nancy; Kasonde, Prisca; Mwiya, Mwiya; Kankasa, Chipepo; Decker, Don; Thea, Donald M; Aldrovandi, Grace M

    2009-09-01

    Single-dose nevirapine (SDNVP) for prevention of mother-to-child HIV transmission selects mutations conferring resistance to nonnucleoside reverse transcriptase inhibitor (NNRTI)-based therapy. We investigated mortality and virologic and clinical outcomes after introduction of antiretroviral treatment (ART) among a cohort of women given SDNVP. When ART programs were introduced in 2004 in Lusaka, Zambia, we were completing a trial of infant feeding, which involved following HIV-infected women who received SDNVP between 2001 and 2005. Women still in follow-up or who could be contacted were evaluated for eligibility for ART (CD4 count or=3) and started on NNRTI-based therapy if eligible. We compared mortality in the cohort of women before and after ART access, and examined, among women initiating ART, whether virologic response was better allowing a longer time to elapse between SDNVP and treatment initiation. In the cohort of 872 women, mortality more than halved after ART became available (relative hazard = 0.46, 95% confidence interval: 0.23 to 0.91, P = 0.03). Of 161 SDNVP-exposed women followed on NNRTI-based ART, 70.8% suppressed (viral load 24 months after exposure (chi2 trend P = 0.01). Most SDNVP-exposed women respond well to NNRTI-based therapy, but there was an attenuation of therapy efficacy that persisted to 12 months after exposure. Women should be screened for ART eligibility during pregnancy and started on effective regimens before delivery.

  19. The Effect of Malnutrition on the Pharmacokinetics and Virologic Outcomes of Lopinavir, Efavirenz and Nevirapine in Food Insecure HIV-Infected Children in Tororo, Uganda

    Science.gov (United States)

    Bartelink, Imke H.; Savic, Rada M.; Dorsey, Grant; Ruel, Theodore; Gingrich, David; Scherpbier, Henriette J.; Capparelli, Edmund; Jullien, Vincent; Young, Sera L.; Achan, Jane; Plenty, Albert; Charlebois, Edwin; Kamya, Moses; Havlir, Diane; Aweeka, Francesca

    2014-01-01

    Background Malnutrition may impact the pharmacokinetics (PK) of antiretroviral medications and virologic responses in HIV-infected children. We therefore evaluated the PK of nevirapine (NVP), efavirenz (EFV) and lopinavir (LPV) in associations with nutritional status in a cohort of HIV-infected Ugandan children. Methods Sparse dried blood spot (DBS) samples from Ugandan children were used to estimate plasma concentrations. Historical PK data from children from three resource-rich countries (RRC) were utilized to develop the PK models. Results Concentrations in 330 DBS from 163 Ugandan children aged 0.7–7 years were analyzed in reference to plasma PK data (1189 samples) from 204 children from RRC aged 0.5–12 years. Among Ugandan children 48% was malnourished (underweight, thin or stunted). Compared to RRC, Ugandan children exhibited reduced bioavailability of EFV and LPV; 11% (P=0.045) and 18% (P=0.008) respectively. In contrast, NVP bioavailability was 46% higher in Ugandan children (Pmalnutrition on bioavailability. In children receiving NVP, the relation between exposure, malnutrition and outcome turned out to be marginally significant. Further investigations are warranted using more intensive PK measurements and adequate adherence assessements, to further assess causes of virologic failure in Ugandan children. PMID:25742090

  20. Impact of baseline CD4(+) T cell counts on the efficacy of nevirapine-based highly active antiretroviral therapy in Chinese HIV/AIDS patients: a prospective, multicentric study.

    Science.gov (United States)

    Liu, Zheng-yin; Guo, Fu-ping; Han, Yang; Qiu, Zhi-feng; Zuo, Ling-yan; Li, Yan-ling; Li, Tai-sheng

    2009-10-20

    CD4(+) T cell counts have been used as the indicator of human immunodeficiency virus type 1 (HIV-1) disease progression and thereby to determine when to start highly active antiretroviral therapy (HAART). Whether and how the baseline CD4(+) T cell count affects the immunological and viral responses or adverse reactions to nevirapine (NVP)-containing HAART in Chinese HIV-1 infected adults remain to be characterized. One hundred and ninety-eight HIV-seropositive antiretroviral therapy (ART)-naive subjects were enrolled into a prospective study from 2005 to 2007. Data were analyzed by groups based on baseline CD4(+) T cell counts either between 100 - 200 cells/microl or 201 - 350 cells/microl. Viral responses, immunologic responses and adverse events were monitored at baseline and at weeks 4, 12, 24, 36, 52, 68, 84, 100. Eighty-six and 112 subjects ranged their CD4(+) T cell counts 100 - 200 cells/microl and 201 - 350 cells/microl, respectively. The pre-HAART viral load in CD4 201 - 350 cells/microl group was significantly lower than that in CD4 100 - 200 cells/microl group (P = 0.000). After treatment, no significant differences were observed between these two groups either in the plasma viral load (pVL) or in the viral response rate calculated as the percentage of pVL less than 50 copies/ml or less than 400 copies/ml. The CD4(+) T cell counts were statistically higher in the 201 - 350 group during the entire follow-ups (P count increases were similar in these two groups. After 100-week treatment, the median of CD4(+) T cell counts were increased to 331 cells/microl for CD4 100 - 200 cells/microl group and to 462 cells/microl for CD4 201 - 350 cells/microl group. Only a slightly higher incidence of nausea was observed in CD4 201 - 350 cells/microl group (P = 0.05) among all adverse reactions, including rash and liver function abnormality. The pVLs and viral response rates are unlikely to be associated with the baseline CD4(+) T cell counts. Initiating HAART in

  1. Inhomogeneous Crustal Structure of the Rifting in the Okinawa Trough, a Backarc Basin West of Kyushu, Japan, Deduced from Seismic Reflection and Refraction Data

    Science.gov (United States)

    Nishizawa, A.; Kaneda, K.; Oikawa, M.; Horiuchi, D.; Fujioka, Y.; Okada, C.

    2017-12-01

    Several depressions found under the thick sediments in the East China Sea shelf have been considered as failed rift basins. Their formation age becomes progressively younger from NW to SE and the youngest rift basin is the Okinawa Trough, an active backarc basin of the Ryukyu (Nansei-Shoto) arc-trench system, to the southwest of Kyusyu, Japan. Its rifting is in progress and related hydrothermal activity is present in the trough. The knowledge of the crustal structure of the trough is fundamental to understand the current active tectonics and predict the future of the trough. We, Japan Coast Guard, have conducted extensive seismic reflection and refraction surveys in the Ryukyu region since 2008 and compiled the seismic structures of the Okinawa Trough. We will show the crustal structures along seven along-trough and ten across-trough seismic survey lines. The P-wave velocity models beneath the Okinawa Trough generally show a thinned continental/island arc crust consisting of upper, middle, and lower crusts. Moho depths below the trough were estimated mainly from Moho reflection (PmP) travel times. The crustal thickness of the trough is thinner than those of the East China Sea shelf and of the Ryukyu Islands. The depth of the Moho below the trough decreases from over 30 km in the north to about 13 km in the south, indicating a difference in degree of the rifting process. The position of the shallowest Moho along the across-trough lines in the northern trough does not necessarily correspond to the center of the trough defined as the deepest water depth, but it corresponds to the transition area between the East China Sea shelf and the Okinawa Trough. An M7.1 earthquake occurred at the transition area on Nov. 14, 2015 (JST) and many aftershocks were observed along the transition. This seismic activity demonstrated that the area is under rifting tectonics in the present.

  2. Towards standardization of in-site parabolic trough collector testing in solar thermal power plants

    Science.gov (United States)

    Sallaberry, Fabienne; Valenzuela, Loreto; de Jalón, Alberto García; Leon, Javier; Bernad, Ignacio David

    2016-05-01

    This paper presents a summary of the testing procedure and a validation of the methodology of parabolic trough collector in solar thermal power plants. The applied testing methodology is the one proposed within the Spanish standardization sub-committee AEN/CTN 206/SC117 working group WG2 related to the components for solar thermal power plants. This methodology is also proposed within the international committee IEC TC 117 (Standard draft IEC 62862-3-2 Ed. 1.0). This study is done at Plataforma Solar de Almería (PSA) in Almeria within the European project STAGE-STE. This paper presents the results of the optical and thermal efficiency of a large-size parabolic trough collector. The obtained values are similar to the previous analysis on this collector by PSA. The results of the tracking system have a good accuracy compared to the acceptance angle of the concentrator.

  3. Study on a Mid-Temperature Trough Solar Collector with Multisurface Concentration

    Directory of Open Access Journals (Sweden)

    Zhengliang Li

    2015-01-01

    Full Text Available A new trough solar concentrator which is composed of multiple reflection surfaces is developed in this paper. The concentrator was analyzed firstly by using optical software. The variation curves of the collecting efficiency affected by tracking error and the deviation angle were given out. It is found that the deviation tolerance for the collector tracking system is about 8 degrees when the receiver is a 90 mm flat. The trough solar concentrators were tested under real weather conditions. The experiment results indicate that, the new solar concentrator was validated to have relative good collecting efficiency, which can be more than 45 percent when it operated in more 145°C. It also has the characteristics of rdust, wind, and snow resistance and low tracking precision requirements.

  4. A biomarker record of temperature and phytoplankton community in Okinawa Trough since the last glacial maximum

    Science.gov (United States)

    Ruan, Jiaping

    2017-04-01

    A variety of biomarkers were examined from Ocean Drilling Program (ODP) core 1202B to reconstruct temperature and phytoplankton community structures in the southern Okinawa Trough for the past ca. 20000 years. Two molecular temperature proxies (Uk37 and TEX86) show 5-6 ℃ warming during the glacial/interglacial transition. Prior to the Holocene, the Uk37-derived temperature was generally 1-4 ℃ higher than TEX86-derived temperature. This difference, however, was reduced to Okinawa Trough, controlled by the sea level and the intensity of Kuroshio Current. The phytoplankton community change may have profound implications on atmospheric CO2 fluctuations during glacial/interglacial cycles since diatoms and dinoflagellates have a higher efficiency of biological pump than coccolithophorids.

  5. Heat Transfer Analysis and Modeling of a Parabolic Trough Solar Receiver Implemented in Engineering Equation Solver

    Energy Technology Data Exchange (ETDEWEB)

    Forristall, R.

    2003-10-01

    This report describes the development, validation, and use of a heat transfer model implemented in Engineering Equation Solver. The model determines the performance of a parabolic trough solar collector's linear receiver, also called a heat collector element. All heat transfer and thermodynamic equations, optical properties, and parameters used in the model are discussed. The modeling assumptions and limitations are also discussed, along with recommendations for model improvement.

  6. Monitoring of Seafloor Crustal Deformation Along the Suruga-Nankai Trough, Japan

    Science.gov (United States)

    Tadokoro, K.; Watanabe, T.; Nagai, S.; Okuda, T.; Ikuta, R.; Eto, S.; Yasuda, K.; Sakata, T.; Sayanagi, K.

    2011-12-01

    \\ \\ \\ The Suruga-Nankai Trough is one of the active plate boundaries in the world. The Philippine Sea plate subducts beneath the Amurian (Eurasian) plate along the Suruga-Nankai Trough, causing major subduction earthquakes. The subduction earthquakes, Nankai and Tonankai earthquakes, have repeatedly occurred with intervals of about 100-150 years. Headquarters for Earthquake Research Promotion, Japanese Government [2011] estimates the 30-years probabilities of the next major earthquakes at 60-70 %. It is necessary to monitor crustal deformation above the source regions of the major earthquakes. The source regions are located beneath the seafloor, and we developed a system for monitoring seafloor crustal deformation [Tadokoro et al., 2006, GRL; Ikuta et al., 2008, JGR]. The system is composed of the precise acoustic ranging with ultrasonic waves and kinematic GPS positioning techniques. \\ \\ \\ We monitor seafloor crustal deformation at five sites altogether along the Suruga-Nankai Trough, three in the Kumano region and two in the Suruga region, with the use of this system. We have repeatedly measured the coordinate of seafloor benchmark installed beforehand every about 2-3 months on the average. The monitoring results, the horizontal site velocities with relative to the Amurian Plate, as of 2010 are approximately 3-4 cm/yr in the direction of N70W at the three sites in the Kumano region, and approximately 2-4 cm/yr in the direction of N85-100W at the two sites in the Suruga region. The observed horizontal seafloor crustal deformations are consistent to the plate convergence along the Suruga-Nankai Trough, showing strain accumulation before the next major subduction earthquakes. Acknowledgments: We are grateful to the captain and crews of R/Vs "Hokuto," Tokai University and "Asama," Mie Prefecture Fisheries Research Institute, Japan. This study has been promoted by Ministry of Education, Culture, Sports, Science and Technology, Japanese Government.

  7. Modeling of a Parabolic Trough Solar Field for Acceptance Testing: A Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M. J.; Mehos, M. S.; Kearney, D. W.; McMahan, A. C.

    2011-01-01

    As deployment of parabolic trough concentrating solar power (CSP) systems ramps up, the need for reliable and robust performance acceptance test guidelines for the solar field is also amplified. Project owners and/or EPC contractors often require extensive solar field performance testing as part of the plant commissioning process in order to ensure that actual solar field performance satisfies both technical specifications and performance guaranties between the involved parties. Performance test code work is currently underway at the National Renewable Energy Laboratory (NREL) in collaboration with the SolarPACES Task-I activity, and within the ASME PTC-52 committee. One important aspect of acceptance testing is the selection of a robust technology performance model. NREL1 has developed a detailed parabolic trough performance model within the SAM software tool. This model is capable of predicting solar field, sub-system, and component performance. It has further been modified for this work to support calculation at subhourly time steps. This paper presents the methodology and results of a case study comparing actual performance data for a parabolic trough solar field to the predicted results using the modified SAM trough model. Due to data limitations, the methodology is applied to a single collector loop, though it applies to larger subfields and entire solar fields. Special consideration is provided for the model formulation, improvements to the model formulation based on comparison with the collected data, and uncertainty associated with the measured data. Additionally, this paper identifies modeling considerations that are of particular importance in the solar field acceptance testing process and uses the model to provide preliminary recommendations regarding acceptable steady-state testing conditions at the single-loop level.

  8. Factor Xa inhibition by rivaroxaban in the trough steady state can significantly reduce thrombin generation.

    Science.gov (United States)

    Horinaka, Shigeo; Sugawara, Rie; Yonezawa, Yutaka; Ishimitsu, Toshihiko

    2018-01-01

    The aim of the present study was to demonstrate evidence of reduced thrombin generation at the trough plasma rivaroxaban concentration. A single-centre, prospective, nonrandomized, drug-intervention, self-controlled study was conducted in 51 anticoagulation therapy-naïve patients with nonvalvular atrial fibrillation. Plasma rivaroxaban concentration was measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) and the anti-factor Xa chromogenic assay. Partial thrombin time (PT), protein C activity, and protein S antigen, prothrombin fragment 1 + 2 (F1 + 2), D-dimer, thrombomodulin (TM), thrombin-antithrombin complex (TAT), plasminogen activator inhibitor-1 (PAI-1) and tissue factor pathway inhibitor (TFPI) levels were also measured at the trough steady state after 4 weeks of rivaroxaban treatment and compared with baseline. Plasma concentrations obtained by the LC-MS/MS and anti-Xa assays were correlated (r = 0.841, P steady state was 23.6 ng ml -1 , at which F1 + 2, TAT and D-dimer had decreased from the baseline values (P steady state in the first to third quartile groups (+0.79 pg ml -1 , P = 0.048). By contrast, PAI-1, protein C activity, protein S antigen and TM remained within the normal range at the trough steady state. Residual plasma rivaroxaban at the trough steady state may explain the antithrombin effect of rivaroxaban in patients with nonvalvular atrial fibrillation. © 2017 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

  9. Evaluation of the shape of a parabolic trough solar collector with flat null-screens

    Science.gov (United States)

    Campos-García, Manuel; Peña-Conzuelo, Andrés.; Díaz-Uribe, José Rufino

    2017-06-01

    We present a method for testing the shape quality of the reflecting surface of a parabolic trough solar collector (PTSC) with flat null-screens. We develop a custom algorithm to reconstruct the surface taking into account the differences between the normal vector of the true surface and the reference one. Also, we perform a numerical simulation to analyze the accuracy of the method by introducing controlled systematic errors such as misalignments of the null-screen or the CCD plane.

  10. Sensitive Analysis for the Efficiency of a Parabolic Trough Solar Collector Based on Orthogonal Experiment

    OpenAIRE

    Xiaoyan Liu; Jing Huang; Qianjun Mao

    2015-01-01

    A multitude of the researches focus on the factors of the thermal efficiency of a parabolic trough solar collector, that is, the optical-thermal efficiency. However, it is limited to a single or double factors for available system. The aim of this paper is to investigate the multifactors effect on the system’s efficiency in cold climate region. Taking climatic performance into account, an average outlet temperature of LS-2 collector has been simulated successfully by coupling SolTrace softwar...

  11. Mesozoic evolution of the Valencia trough: Implications for the understanding of the Western Mediterranean

    Science.gov (United States)

    Etheve, Nathalie; Frizon de Lamotte, Dominique; Mohn, Geoffroy; Roca, Eduard; Gorini, Christian; Blanpied, Christian

    2014-05-01

    The Western Mediterranean records a multi-stage tectonic evolution characterized by a complex succession of rifting to compressive episodes during the Cenozoic. The Valencia through was formed in this geodynamic framework and is classically interpreted as an aborted Tertiary rift related to back-arc extension. Notably, the Tertiary rifting is superimposed to the Jurassic opening of the Tethys basin, the early Cretaceous opening of the Bay of Biscay-Pyrenees basins and the late Cretaceous-early Tertiary inversion of these basins (e.g. Iberian range, Catalan Coastal range). Since the last twenty years, many studies contributed to the understanding of the Tertiary history of this area, whereas the pre-Tertiary evolution of the Valencia trough remains poorly investigated. Therefore, we initiated a research project in the Valencia trough benefiting from the acquisition of high quality seismic surveys allowing a better imaging of the Mesozoic sequences. This PhD project aims to understand the mechanisms and the role of structural inheritance that controlled the evolution of the Valencia trough and its impact on the sedimentary infilling since the Mesozoic. The relation between the sedimentary infilling, subsidence and crustal thinning mechanisms during the Cenozoic are investigated aiming to unravel critical information on rifting processes. This study will be based on correlations between onshore and offshore observations. Structural and stratigraphic evolution will be defined on land and compared with seismic sections and well data at sea. Eventually, these data will enable us to propose coherent land-sea interpretations of the area, providing a better understanding of the tectono-stratigraphic context. Our poster show preliminary results obtained from fieldwork on the western margin of the Valencia trough coupled with seismic interpretations. Eventually, results of this study may lead to better constrain the kinematic reconstruction of the western Mediterranean

  12. Infliximab Dosing Strategies and Predicted Trough Exposure in Children with Crohn’s Disease

    Science.gov (United States)

    Frymoyer, Adam; Piester, Travis L; Park, KT

    2016-01-01

    Objectives Standard infliximab maintenance dosing of 5 mg/kg every 8 weeks may be inadequate to consistently achieve sufficient drug exposure to minimize loss of response or treatment failure in pediatric Crohn’s disease (CD). We aimed to determine the predicted infliximab trough concentrations in children with CD during maintenance therapy and the percentage of patients achieving target trough concentration >3 μg/ml. Methods A Monte Carlo simulation analysis was constructed using a published population pharmacokinetic model based on data from 112 children in the REACH trial. We assessed maintenance dosing strategies of 5, 7.5, and 10 mg/kg at dosing intervals of every 4, 6, and 8 weeks for children that differed by age, weight, albumin level, and concomitant immunomodulator therapy. Results Based on the index case of a 10 year old with CD receiving standard infliximab dosing with concomitant immunomodulator therapy, the median (IQR) simulated infliximab trough concentration at week 14 was 1.3 (0.5–2.7) μg/ml, and 2.4 (1.0–4.8) μg/ml for albumin levels of 3 and 4 g/dl, respectively. Among 1000 simulated children in the model, trough concentration >3 μg/ml at week 14 was achieved 21% and 41% of the time for albumin levels of 3 and 4 g/dl, respectively. Conclusions Standard infliximab maintenance dosing in children with CD is predicted to frequently result in inadequate exposure, especially when albumin levels are low. Optimized dosing strategies for individual patients are needed to achieve sufficient drug exposure during infliximab maintenance therapy. PMID:26890885

  13. Cascade system using both trough system and dish system for power generation

    International Nuclear Information System (INIS)

    Zhang, Cheng; Zhang, Yanping; Arauzo, Inmaculada; Gao, Wei; Zou, Chongzhe

    2017-01-01

    Highlights: • A novel solar cascade system using both trough and dish collectors is proposed. • Heat rejected by the Stirling engines is collected by the condensed water. • The directions to increase the efficiency improvement has been pointed out • Influence of flow type of heating/cooling fluids of Stirling engines is considered. - Abstract: This paper represents a novel solar thermal cascade system using both trough and dish systems for power generation. An effective structure using the condensed fluid of Rankine cycle to cool the Stirling engines to use the heat released by Stirling engines was proposed. The cascade system model with different fluid circuits was developed. The models of some important components of the system, such as dish collector, trough collector and Stirling engine array, are presented with detail explanation in this paper. Corresponding stand-alone systems were also developed for comparison. Simulations were conducted with the models to find out efficiency difference between cascade system and corresponding stand-alone systems. The directions to increase the efficiency difference were also considered. Results show that the cascade system can achieve a higher efficiency with a high solar irradiance (>550 W/m 2 ). The flow type of fluids between heating and cooling Stirling engine array is also required to concern on designing a cascade system with Stirling engine array.

  14. Use of deep seismic shooting to study graben-like troughs. [Urals

    Energy Technology Data Exchange (ETDEWEB)

    Makalovskiy, V.V.; Silayev, V.A.

    1983-01-01

    In the Southeast Perm Oblast, in the zone of articulation of the Russian platform and the Cisural trough, in order to study the structure of the graben-like troughs together with deep drilling, well seismic exploration is used by the method of deep seismic shooting (DSS). The DSS method developed by the Kamskiy department of the VNIGNI consists of blasting in the well shaft and recording of the elastic fluctuations on the Earth's surface. The use of the DSS made it possible to pinpoint structural details of the graben-like trough, and to clarify that this is in essence a zone of fracturing, where the lowered blocks alternated with elevated, and to establish the location and amplitude of the tectonic disorders. High geological information content, low labor intensity and rapidity of obtaining the results make it possible to recommend the DSS together with prospecting and exploratory drilling to study complexly constructed objects in order to reduce the number of unproductive wells.

  15. Optical Tests on a Curve Fresnel Lens as Secondary Optics for Solar Troughs

    Directory of Open Access Journals (Sweden)

    D. Fontani

    2017-01-01

    Full Text Available A curve Fresnel lens is developed as secondary concentrator for solar parabolic troughs to reduce the number of photovoltaic cells. Specific measurements and optical tests are used to evaluate the optical features of manufactured samples. The cylindrical Fresnel lens transforms the focal line, produced by the primary mirror, into a series of focal points. The execution of special laboratory tests on some secondary concentrator samples is discussed in detail, illustrating the methodologies tailored to the specific case. Focusing tests are performed, illuminating different areas of the lens with solar divergence light and acquiring images on the plane of the photocell using a CMOS camera. Concentration measurements are carried out to select the best performing samples of curve Fresnel lens. The insertion of the secondary optics within the concentrating photovoltaic (CPV trough doubles the solar concentration of the system. The mean concentration ratio is 1.73, 2.13, and 2.09 for the three tested lenses. The concentration ratio of the solar trough is 140 and approaches 300 after the introduction of the secondary lens.

  16. Parabolic trough solar concentrators: a technology which can contribute towards pakistan's energy future

    International Nuclear Information System (INIS)

    Masood, R.

    2013-01-01

    The utilization of solar thermal energy has got prime importance in Pakistan due to the current energy scarcity and escalating cost scenario in the country. Parabolic Trough Solar Concentrator is one of the most reliable technologies for utilization of solar thermal energy. In solar thermal power generation, Parabolic Trough Solar Concentrators are most successful as almost 96 percent of total solar thermal power is generated across the world by utilizing this technology. Its high reliability, operational compatibility, comparative low cost and high efficiency adds to its high value among other resources. Fortunately, Pakistan lies in the high Solar Insolation Zone; thus, a huge potential exists to benefit from this technology. This technology may cater to the Pakistan's seasonal increased electricity demand. Apart from electric power generation, this technology may also have cost-effective solutions for Pakistan's other industries, like steam generation, preheating of boiler make-up water, air-conditioning, and hot water production for food, textile, dairy and leather industries. However, economic justification of such projects would be possible only on accomplishing an indigenous technology base. Globally, this is a proven technology, but in Pakistan there is hardly any development in this field. In this study, an effort has been made by designing and fabricating an experimental Parabolic Trough Solar Water Heater by utilizing locally available materials and manufacturing capabilities. On achieving encouraging results, a solar boiler (steam generator) is proposed to be manufactured locally. (author)

  17. V-trough concentrator on a photovoltaic full tracking system in a hot desert climate

    Energy Technology Data Exchange (ETDEWEB)

    Shaltout, M.A.M.; Ghettas, A.; Sabry, M. [National Research Inst., of Astronomy and Geophysics, Cairo (Egypt)

    1995-11-01

    A V-trough concentrator with a two-axis tracker system to increase the performance of photovoltaics was designed by the authors and installed on the roof-top of the building of the National Research Institute of Astronomy and Geophysics at Helwan in South Cairo. The V-trough concentrator system comprises two flat mirrors with dimensions 50 cm x 18 cm. They are fixed with the reflecting surfaces facing each other with a separation of about 11 cm, on a wooden table of 50 cm axis length. A sample of polycrystalline amorphous silicon cells were fixed into the system, and similar solar cells of each type were fixed separate to the system, to estimate the electrical gain. The measurements were performed daily at different air masses for one complete year. The temperature of the solar cells in and out of the system were measured for comparison. Also, measurements for beam and global solar radiation and other meteorological conditions were recorded. The optical losses of the system were analyzed and details of collectable energy calculations are presented. The energy gain from the isolated contribution of the V-trough concentrators is also evaluated. (Author)

  18. Corrosion rate evaluation of the carbon steel trough electrochemical techniques

    Directory of Open Access Journals (Sweden)

    Jeimmy González-Masís

    2014-02-01

    Full Text Available Usually the atmospheric corrosion studies are cha­racterized by their long duration, months and even years. However electrochemical techniques have been developed, recent in comparison to other methods, allowing obtain real-time data, including corrosion rate. In this research electrochemical noise and lineal polarization resistance tests are valued, so obtained data were analyzed, relations were establis­hed between the graphics form and the corrosion type, as well as the relationship between the corro­sion data and atmospheric conditions, to find, finally, there is a more consistent behavior when the lineal polarization resistance test is used with the three comb-type electrodes electrochemical monitor.

  19. Evaluation of quinua lines obtained trough mutagenesis and conventional methods

    International Nuclear Information System (INIS)

    De la Cruz, E.; Garcia, J. M; Gonzalez, J.; Brunner, I.; Rubluo, A.; Guadarrama, S

    2001-01-01

    Chenopodium quinoa is an ancient crop that due to its hardiness, nutritive value, and ability to strive under marginal conditions is considered as a crop for modern times, considering the current demands of highly nutritive products obtained through sustainable agricultural practices. The research on quinua began in Mexico in the early eighties, considering it as an alternative crop to peasants living in impoverished regions, characterised by marginal soils. Research institutions such as the Instituto de Investigacion Agricola del Estado de Mexico (ICAMEX), Colegio de Postgraduados and Universidad Autonoma Chapingo, began to evaluate varieties from South-America and eventually established a breeding programme on quinua. One goal of the quinua research programme in Mexico is the reduction of saponin content, so a mutation breeding approach was designed in the early nineties being the Instituto Nacional de Investigaciones Nucleares (ININ) involved. In the 1999-2000 period, field trials of low saponin putative mutants obtained through irradiation of Barandales variety were performed, including also elite lines supplied by the National Germplasm Bank (NGB) at Chapingo, Mexico. The results from this trials indicate that the low saponin content character in the putative mutants remains in the M5 generation. Also eleven early maturing lines were detected. Climatic conditions prevalent in that period exhibited the resistance of quinua to spring frosts, furthermore, the evaluation of advanced lines from the (NGB) showed high variability regarding to morphological, agronomic and seed quality characters which Hill allow us to advance in the search for superior quinua lines

  20. Plasma tenofovir trough concentrations are associated with renal dysfunction in Japanese patients with HIV infection: a retrospective cohort study

    OpenAIRE

    Kunimoto, Yusuke; Ikeda, Hiroshi; Fujii, Satoshi; Kitagawa, Manabu; Yamazaki, Kieko; Nakata, Hiromasa; Noda, Norimasa; Ishida, Tadao; Miyamoto, Atsushi

    2016-01-01

    Background Plasma tenofovir (TFV) trough concentrations may be relevant for tenofovir disoproxil fumarate (TDF)-induced renal dysfunction. The purpose of this study was to determine the association between plasma TFV trough concentrations and TDF-induced renal dysfunction in Japanese patients with human immunodeficiency virus (HIV) infection. Methods A 48-week, retrospective cohort study was performed with Japanese patients with HIV infection who started a TDF-containing combination antiretro...

  1. On the CFD&HT of the flow around a parabolic trough solar collector under real working conditions

    OpenAIRE

    Amine Hachicha, Ahmed; Rodríguez Pérez, Ivette María; Lehmkuhl Barba, Oriol; Oliva Llena, Asensio

    2013-01-01

    Parabolic trough solar collector is currently one of the most mature and prominent solar applications for production of electricity. These systems are usually located in open terrain where strong winds may occur and affect their stability and optical performance, as well as, the heat exchange between the solar receiver and the ambient air. In this context, a wind flow analysis around a parabolic trough solar collector under real working conditions is performed. A numerical aerodynamic and ...

  2. Morphology and Sediment Transport Dynamics of a Trough-Blowout Dune, Bodega Marine Reserve, Northern California

    Science.gov (United States)

    Jorgenson, D.; Dunleavy, C. J.; Smith, M. E.

    2014-12-01

    Blowout dunes are a primary mechanism for transporting sand within vegetated coastal dune systems. Understanding the fine-scale variation in sediment transport within these systems is critical to predicting their formation and migration. Previous investigations of a coastal dune system located at the Bodega Marine Reserve, on the Sonoma Coast of Northern California have indicated that aeolian sand flux in unvegetated sand is ~450x greater than in vegetated areas. To better understand sand flux and its relationship with wind speed, direction and precipitation, we deployed an array of 12 sand traps within a single blowout area adjacent to the BOON marine climatology station. The blowout is trough- shaped, approximately 50 meters long and 15 meters wide. Its main 'fairway' is 5-10 meters below the surrounding beach grass (Ammophila)-covered land surface. Surface sediment within the blowout is fine-grained to granule-sized lithic to sub-lithic sand, and is coarsest in the center. Dune sediment in the Bodega Marine Reserve has been transported by aeolian processes from Salmon Creek Beach to the NW. Within the blowout, typical bedforms include 15-25 cm-wavelength, ~10 cm high sinuous to lingoid ripples arranged perpendicularly to the dominant wind direction (~280 degrees). An 8-10 meter-high mound at the downwind end has accumulated due to the trapping of sand flux by vegetation. Sediment flux across the studied blowout was sampled monthly over a 10-month period of 2013-2014. Sand traps were constructed using modified PVC cylinders, and are 0.5 meter high and 0.3 meter in diameter, with a 0.74-micron mesh screen. Based on measured sand flux, the sites can be categorized into three groups-axial, medial, and peripheral. Rates increase downwind within the blowout. Inter-site sand flux variability within unvegetated locations of the blowout is greater than two orders of magnitude. Axial sites, which experience the greatest sand flux, occur on the edge of the blowout adjacent

  3. Paleoseismic events inferred from marine seismogenic turbidites of the eastern Nankai Trough

    Science.gov (United States)

    Okutsu, N.; Ashi, J.; Omura, A.; Yamaguchi, A.; Suganuma, Y.; Kanamatsu, T.; Murayama, M.

    2016-12-01

    Paleoseismology using marine seismogenic turbidites is a developing field especially in subduction margins. However, very fine-grained turbidites are difficult to distinguish from hemipelagic mud. The primary focus of this study is to understand the characteristics of the muddy turbidites. The second focus is to discuss the muddy turbidites distributions and their ages from a longer sediment core, and understand the paleoseismic records of eastern Nankai Trough, Japan. The samples used in this study include multiple cores and a piston core which were collected from the sedimentary basin southwest off Kii Peninsula during the R/V Shinsei Maru KS-14-8 cruise. The sampling site is located at the ENE-WSW elongated basin between the accretionary prism and the forearc basin off Kumano without terrestrial sediment supply. The basin exhibits a terminal basin that captures all sediments supplied from outside. From the multiple core samples, the Cs-137 and Pb- 210 concentration distribution indicates that the muddy sediment layer in the upper 17 cm was formed from the 2004 off the Kii Peninsula earthquake. Visual observation and X-ray CT scans were conducted alongside other measurements for anisotropy of magnetic susceptibility (AMS), paleomagnetism, rock magnetism, electrical resistivity, and X-ray fluorescence core scanning (XRF). Muddy seismogenic turbidites associated with the 2004 off the Kii Peninsula earthquake have thick homogeneous clay layer above the silty lamination. The magnetic susceptibility decreases upwards in the lamination. This specific feature is thought to have formed as the muddy turbiditity current slowly decelerated and slowly settled down the slope. From the results of XRF core scanning, Ca and Fe have a peak at basement of turbidites, and decrease upwards. Ca is thought to correspond to amount of the foraminiferas. In piston core, we observed the same sedimentary and magnetic characteristics as the multiple cores. Based on stratigraphic information

  4. Comparative Single-Cell Genomics of Chloroflexi from the Okinawa Trough Deep-Subsurface Biosphere.

    Science.gov (United States)

    Fullerton, Heather; Moyer, Craig L

    2016-05-15

    Chloroflexi small-subunit (SSU) rRNA gene sequences are frequently recovered from subseafloor environments, but the metabolic potential of the phylum is poorly understood. The phylum Chloroflexi is represented by isolates with diverse metabolic strategies, including anoxic phototrophy, fermentation, and reductive dehalogenation; therefore, function cannot be attributed to these organisms based solely on phylogeny. Single-cell genomics can provide metabolic insights into uncultured organisms, like the deep-subsurface Chloroflexi Nine SSU rRNA gene sequences were identified from single-cell sorts of whole-round core material collected from the Okinawa Trough at Iheya North hydrothermal field as part of Integrated Ocean Drilling Program (IODP) expedition 331 (Deep Hot Biosphere). Previous studies of subsurface Chloroflexi single amplified genomes (SAGs) suggested heterotrophic or lithotrophic metabolisms and provided no evidence for growth by reductive dehalogenation. Our nine Chloroflexi SAGs (seven of which are from the order Anaerolineales) indicate that, in addition to genes for the Wood-Ljungdahl pathway, exogenous carbon sources can be actively transported into cells. At least one subunit for pyruvate ferredoxin oxidoreductase was found in four of the Chloroflexi SAGs. This protein can provide a link between the Wood-Ljungdahl pathway and other carbon anabolic pathways. Finally, one of the seven Anaerolineales SAGs contains a distinct reductive dehalogenase homologous (rdhA) gene. Through the use of single amplified genomes (SAGs), we have extended the metabolic potential of an understudied group of subsurface microbes, the Chloroflexi These microbes are frequently detected in the subsurface biosphere, though their metabolic capabilities have remained elusive. In contrast to previously examined Chloroflexi SAGs, our genomes (several are from the order Anaerolineales) were recovered from a hydrothermally driven system and therefore provide a unique window into

  5. Overview of the Kinematics of the Salton Trough and Northern Gulf of California

    Science.gov (United States)

    Stock, J. M.

    2016-12-01

    In the Salton Trough and Northern Gulf of California, transtensional rifting is leading to full continental plate breakup, as a major continental block is being transferred to an oceanic plate. Since at least 6 Ma this region has taken up most of the plate boundary slip between the Pacific and North America plates at this latitude. We review the structural history of plate separation, as constrained by many recent studies of present and past fault configurations, seismicity, and basin development as seen from geology and geophysics. Modern activity in the USA is dominated by NW-striking strike-slip faults (San Andreas, San Jacinto, Elsinore), and subsidiary NE-striking faults. There is an equally broad zone in Mexico (faults from the Mexicali Valley to the Colorado River Delta and bounding the Laguna Salada basin), including active low-angle detachment faults. In both areas, shifts in fault activity are indicated by buried faults and exhumed or buried earlier basin strata. Seismicity defines 3 basin segments in the N Gulf: Consag-Wagner, Upper Delfin, and Lower Delfin, but localization is incomplete. These basins occupy a broad zone of modern deformation, lacking single transform faults, although major strike-slip faults formed in the surrounding continental area. The off-boundary deformation on the western side of the plate boundary has changed with time, as seen by Holocene and Quaternary faults controlling modern basins in the Gulf Extensional Province of NE Baja California, and stranded Pliocene continental and marine basin strata in subaerial fault blocks. The eastern side of the plate boundary, in the shallow northeastern Gulf, contains major NW-striking faults that may have dominated the earlier (latest Miocene-early Pliocene) kinematics. The Sonoran coastal plain likely buries additional older faults and basin sequences; further studies here are needed to refine models of the earlier structural development of this sector. Despite > 250 km of plate

  6. Biogeochemical processes controlling authigenic carbonate formation within the sediment column from the Okinawa Trough

    Science.gov (United States)

    Li, Jiwei; Peng, Xiaotong; Bai, Shijie; Chen, Zhiyan; Van Nostrand, Joy D.

    2018-02-01

    Authigenic carbonates are one type of conspicuous manifestation in seep environments that can provide long-term archives of past seepage activity and methane cycling in the oceans. Comprehensive investigations of the microbial community functional structure and their roles in the process of carbonate formation are, however, lacking. In this study, the mineralogical, geochemical, and microbial functional composition were examined in seep carbonate deposits collected from the west slope of the northern section of the Okinawa Trough (OT). The aim of this work was to explore the correspondence between the mineralogical phases and microbial metabolism during carbonate deposit formation. The mineralogical analyses indicated that authigenic carbonate minerals (aragonite, magnesium-rich calcite, dolomite, ankerite and siderite) and iron-bearing minerals (limonite, chlorite, and biotite) were present in these carbonate samples. The carbon and oxygen isotopic values of the carbonate samples varied between -51.1‰ to -4.7‰ and -4.8‰ to 3.7‰, respectively. A negative linear correlation between carbon and oxygen isotopic compositions was found, indicating a mixture of methane-derived diagenetic (low δ13C/high 18O) carbonates and detrital origin (high δ13C/low 18O) carbonates at the OT. GeoChip analyses suggested that various metabolic activities of microorganisms, including methanogenesis, methane oxidation, sulfite oxidation, sulfate reduction, and metal biotransformations, all occurred during the formation process. On the basis of these findings, the following model for the methane cycle and seep carbonate deposit formation in the sediment column at the OT is proposed: (1) in the upper oxidizing zone, aerobic methane oxidation was the main way of methane consumption; (2) in the sulfate methane transition zone, sulfate-dependent AOM (anaerobic oxidation of methane) consumes methane, and authigenic minerals such as aragonite, magnesium-calcite, and sulfide minerals

  7. Pore-Water Freshening in the Nankai Trough, Japan: Implications for Lateral Fluid Flow

    Science.gov (United States)

    McKiernan, A. W.; Saffer, D. M.

    2004-12-01

    Pore-water freshening has been observed in ocean sediments cored along the Muroto Transect in the Nankai Trough, offshore Japan during ODP Legs 190/196. Chloride concentrations up to ˜11% below normal seawater values ([Cl-] ˜555 mM) were documented at drill site 1173, 13 km seaward of the trench. Updip, lateral fluid flow from depth, and in situ clay dehydration have been proposed as freshening sources. Placing realistic bounds on the relative contributions of these potential sources has importance for quantifying fluid and chemical fluxes in subduction zones. Here, we evaluate the hypothesis that freshening is due solely to in situ clay dehydration. We simulate the general shape and magnitude of the down hole [Cl-] anomaly observed at site 1173 using a one-dimensional model which combines sedimentation, thermal history, clay dehydration, and Cl- diffusion. Sediment accumulation during arcward transport and high heat flow for the area ( ˜180 mW/m2), result in temperatures sufficient to transform smectite to illite + H20. The volume of released water scales with initial smectite abundance (here we assume 50% by weight based on mineralogy at site 1177, where heat flow is low and clays are less reacted). In the model, released water is added at each time step creating unstable [Cl-] profiles. Chloride diffusion is modeled implicitly in a reference frame fixed to the interstitial water column, through which consolidating sediment nodes move. Basal boundary conditions used in the model are: constant [Cl-], no-flow, and the inclusion of oceanic crust in diffusion. Simulated reaction progress matches observed clay mineralogy for site 1173. Minimum simulated [Cl-] scales with initial smectite content, ranging from 4% freshening for 20% initial smectite, to 14% freshening for 70% initial smectite. Simulated [Cl-] profiles for all boundary conditions mimic the general [Cl-] profile for site 1173, but no single boundary matches observed data exactly. A no-flow basal

  8. Lena Trough MORB: Trace Element and Isotopic Composition of a Very Slow Spreading Ridge

    Science.gov (United States)

    Nauret, F.; Weis, D.; Snow, J. E.

    2005-12-01

    Extreme non-hotspot MORB compositions are less straightforward to explain than comparable OIB's, where all manner of enriched components may be derived from plume material. Here we report a new isotope and trace element study of dredged samples from the ultra-slow (7.5 mm/yr effective full-rate) Lena Trough rift in the Arctic Ocean and the western end of Gakkel Ridge (13mm/yr full rate). The few basalts found in Lena Trough are alkali-MORB with an extreme enrichment of incompatible trace elements, particularly alkalies and Ba (Ba/Th=350±50, Ba/Nb=17±1, Nb/U=69±, (La/Sm)PM=1.39±0.25) and by a garnet-source signature with (Dy/Yb)PM=1.22±0.06. The range of radiogenic isotopic ratios is 87Sr/86Sr=0.7036-0.7044, 143Nd/144Nd=0.51277-0.51230, 206Pb/204Pb=17.75-17.99, 207Pb/204Pb=15.41-15.44 and 208Pb/204Pb=37.54-37.79. In comparison, Western Gakkel Ridge MORB compositions are similar to N-MORB (Ba/Th=143±60, Ba/Nb=11±3, Nb/U=45±6, 87Sr/86Sr=0.7029-0.7030, 143Nd/144Nd=0.51307-0.51310, 206Pb/204Pb=17.97-18.08, 207Pb/204Pb=15.43-15.44, and 208Pb/204Pb=37.73-37.81). The Lena Trough high-precision MC-ICP-MS Pb data define linear Pb-Pb arrays extending to quite unradiogenic values. These arrays extend towards the more radiogenic values of some Gakkel MORBs, which show very limited variations on their own. Together with negative linear correlations between trace element ratios and Nd-Pb isotope systematics, we interpret these Pb linear arrays as reflecting mixing between a DMM component (similar to Gakkel Ridge MORB source) and a highly enriched component, with radiogenic Sr isotopes but low Nd and Pb isotopic ratios. The Lena Trough source contains residual garnet and is preferentially sampled by low degree partial melting. The source of the enriched component of the Lena Trough alkali MORB is interpreted to be olivine-free pyroxenite, taking into account the shallow pressure of partial melting, indicated by major elements. This is a clear indication of a "mantle vein

  9. Variability of the Antarctic Circumpolar Current transport through the Fawn Trough, Kerguelen Plateau

    Science.gov (United States)

    Vivier, Frédéric; Park, Young-Hyang; Sekma, Hela; Le Sommer, Julien

    2015-04-01

    The Kerguelen Plateau is a major topographic obstacle to the eastward flowing Antarctic Circumpolar Current (ACC). While approximately two-third of the ACC transport is diverted to the North, most of the remaining flow engulfs in the Fawn Trough, the only deep passage across the plateau. As part of the TRACK (TRansport ACross the Kerguelen plateau) project, three mooring lines of current meters were deployed in the Fawn Trough for one year in February 2009, underneath ground-track 94 of the Jason-2 satellite altimeter. Full depth CTD-LADCP casts carried out during the deployment cruise were previously analyzed to provide a comprehensive description of the regional circulation, featuring in particular a volume transport of ~43 Sv across the Fawn Trough (Park et al., 2009). Here we present a time series of the transport in the Fawn Trough estimated from current meter observations, featuring a mean eastward transport of 34 Sv (possibly biased low by at most 5 Sv) and a root mean squared variability of 6 Sv, consistent with LADCP estimates (43 Sv in February 2009 and 38 Sv in January 2010). In addition, we analyze to what extent the transport can be directly monitored from along-track satellite altimeter data, which would enable study of the variability of the Fawn Trough Current from a now 20-year long archive. The ability to reconstruct the flow from a limited set of moored instruments as well as from altimeter-derived surface geostrophic velocity is further assessed from synthetic data extracted from a high-resolution peri-Antarctic simulation. While a canonical method to derive transport from altimetry, previously applied to the Malvinas Current, gives here unsatisfactory comparisons with in situ estimates, an ad hoc approach using only the two northernmost mooring lines yields an estimate well correlated (~0.8) with in situ transport at subseasonal time scales during the one year period of observations. At interannual time scales, however, both methods provide

  10. Modelling the Evolution of a Passive Margin: Application to the Rockall Trough

    Science.gov (United States)

    Smithells, R. A.; Egan, S.; Clarke, S.; Kimbell, G.; Johnson, H.

    2012-12-01

    The Rockall Trough is one of the largest, relatively unexplored basins forming the North-East Atlantic passive margin and many aspects regarding the evolution of this basin remain unresolved. In part, this is due to the Paleocene lavas associated with the opening of the North Atlantic Margin and the Icelandic Hotspot which inhibit high resolution imaging of the underlying sediments and basement structure. The aim of this study is to apply numerical, lithosphere-scale models to the Rockall Trough in order to gain insights into the complex evolution of this passive margin basin. Model cross-sections of the basin have been produced in order to determine the interplay of geological, rheological and geodynamic processes that have controlled the evolution of the Rockall Basin. These models are used to test different hypotheses regarding the timing and nature of extensional and compressional events as well as the influence of thermal anomalies, and spatial and temporal variations in lithospheric rheology. Initial results demonstrate the importance of accurate controls on palaeobathymetry and the need to realistically account for varying basin fill sequences during different stages of the Rockall Trough's evolution. An analysis of available subsurface data has been undertaken to quantify the amount of stretching that has occurred during the evolution of the Rockall Trough. Additionally, analyses of composite well data have been used to generate subsidence curves for the basin, which highlight key episodes of anomalous subsidence. The main event highlighted by the subsidence curves is a major deepening event which occurred during the Eocene Epoch. These curves are compared to modelled subsidence curves in order to test the validity of the structural and geodynamic scenarios that have been modelled. Further validation of the model results has been carried out by comparing regional gravitational anomaly data with theoretical gravity anomalies calculated from the model

  11. Exploring Unconventional Hydrocarbons in the Makó Trough, Pannonian basin, Hungary: Results and Challenges

    Science.gov (United States)

    Horvath, Anita; Bada, Gabor; Szafian, Peter; Sztano, Orsolya; Law, Ben; Wallis, Rod

    2010-05-01

    The latest phase exploration in the Makó Trough, which commenced a few years ago, has focused on the utilization of unconventional hydrocarbons. Accumulations are regarded as "unconventional" when they cannot be produced economically except by means of some sort of stimulation, usually hydraulic fracturing. The model we have developed for the evaluation of the hydrocarbon potential indicates a significant gas accumulation in the area of the Makó Trough. The tally of the distinctive attributes of the hydrocarbon system and the combined analysis of the available geological data led to the conclusion that the Makó Trough represents an area of active basin-centered gas accumulation (BCGA), with very significant perspective reserves. In a BCGA, hydrocarbons do not accumulate conventionally, in structural or stratigraphic traps, but rather in cells. Due to the geological setting of the Makó Trough, the hydrocarbon cell here forms a relatively continuous zone marked by considerable internal lithological and petrophysical variability. The most prolific parts, called sweet spots, possess a reservoir potential higher than the average. The identification of these sweet spots constitutes one of the most important, and quite possibly the most challenging task of the entire exploration project. The hemipelagic Endrőd Formation, which acts as the source rock, contains organic-rich marls in a depth delimited by the 170-230 °C isotherms. These marls constitute the still active hydrocarbon "kitchen" of the BCGA in the Makó Trough. The top and bottom boundaries of the cell essentially coincide with the turbidites of the Szolnok Formation and the top of the pre-Neogene basement, respectively. In light of the fact that pressure, temperature, and maturity tests have produced rather similar results in a number of wells in the area, we have reason to believe that the extension of the Makó Trough's BCGA is of regional dimensions (>1000 km2). The thickness and lateral extension of

  12. Study On Seismic Identification And Distribution Characters Of Marine Gas Hydrate In Okinawa Trough

    Science.gov (United States)

    Fang, Y.; Jin, X.; Li, M.; Tang, Y.

    2003-04-01

    The paper studies the formation processes and distribution of marine gas hydrate, through systematically and thoroughly analyzing the geological setting, gas sources and distribution features of the most marine gas hydrate deposits around the world. Based on study of the geologic features in Okinawa Trough and adjacent area, it is showed that there exist favorable geological conditions for the formation of gas hydrate, and the seismic indicator -BSR has also been identified from multi-channel digit seismic data by re-processing and analyzing. This shows that Okinawa Trough and adjacent sea area may distribute a mass of gas hydrate sedimentary deposit. Then the paper discusses the prospect of the gas hydrate resource in Okinawa Trough and adjacent sea area, based on the calculating of the hydrate stability zone thickness. Main conclusions of the paper can be summed up as follows: Based on the systematically comparative analysis of the marine gas hydrate deposits in different marine gas hydrate accumulate belts, the paper summarizes the different geologic formation processes and characters of the gas hydrate. And the importance of the continuous supplementation of the gas source, the transporting and accumulating of the gaseous fluid during the formation processes of the gas hydrate, and the preservation conditions of the gas hydrate deposit are discussed. It is thought that the Okinawa Trough (especially the west slope of the Trough) has the favorable conditions for gas hydrate through the analysis of its geologic features. The geologic features of Okinawa Trough, such as water depth, low temperature of bottom water, very thick sediments with high organic matter content, a large amount of gas from deep parts induced by the upward of the high temperature mantle flow under the Trough, very developed fracture system, and lots of pore space in the under-compacted sediment induced by the rapid sedimentation-are beneficial to form gas hydrate. This provided the advantaged

  13. Efficacy of Six-Week Extended-Dose Nevirapine Varies by Infant Birth Weight with Greatest Relative Efficacy in Low Birth Weight Infants.

    Directory of Open Access Journals (Sweden)

    Nikhil Gupte

    Full Text Available Latest World Health Organization guidelines recommend weight-based nevirapine prophylaxis for all HIV-exposed infants in resource-limited settings, yet low birth weight (LBW infants (2000 g and ≤ 2500 g, and normal birth weight (NBW > 2500 g. Outcomes were HIV-1 infection, HIV-1 infection or death by 12 months, and severe adverse events (SAEs. The Kaplan-Meier method was used to estimate probability of efficacy outcomes in birth weight groups, and differential effects of SWEN by birth weight group were examined using Cox proportional hazards models adjusting for independent risk factors for HIV maternal-to-child transmission and significant covariates. Among 50 VLBW, 249 MLBW, and 433 NBW infants, 50% were randomized to SWEN; median gestational age was 36, 38 and 38 weeks, respectively; and there was no difference in breastfeeding duration (p = 0.99. Compared to SD: SWEN-treated VLBW had lower estimates of HIV-1 infection (13% vs. 38%, p = 0.004 and HIV-1 infection or death (13% vs. 41%, p = 0.002; SWEN-treated MLBW had lower estimated HIV-1 infection (13% vs. 17%, p = 0.042; and efficacy endpoints were similar by treatment arm in NBW. In multivariate analysis, SWEN was associated with reduced risk of HIV-1 infection or death by 83% (p = 0.03 in VLBW versus 45% (p = 0.05 in MLBW. SAE frequency was similar by treatment arm in VLBW (68% vs. 76%, p = 0.53 and MLBW (37% vs. 36%, p = 0.93. SWEN may safely increase HIV-free survival among HIV-exposed LBW infants with greatest protective advantage among infants ≤ 2000 g.

  14. A Pharmacogenetics Study in Mozambican Patients Treated with Nevirapine: Full Resequencing of TRAF3IP2 Gene Shows a Novel Association with SJS/TEN Susceptibility

    Directory of Open Access Journals (Sweden)

    Cinzia Ciccacci

    2015-03-01

    Full Text Available Steven–Johnson Syndrome (SJS and Toxic Epidermal Necrolysis (TEN are severe adverse drug reactions, characterized by extensive epidermal detachment and erosions of mucous membrane. SJS/TEN is one of the most serious adverse reactions to Nevirapine (NVP treatment, commonly used in developing countries as first-line treatment of human immunodeficiency virus infection. In the last years TRAF3IP2 gene variants had been described as associated with susceptibility to several diseases such as psoriasis and psoriatic arthritis. We hypothesized that this gene, involved in immune response and in NF-κB activation, could also be implicated in the SJS/TEN susceptibility. We performed a full resequencing of TRAF3IP2 gene in a population of patients treated with NVP. Twenty-seven patients with NVP-induced SJS/TEN and 78 controls, all from Mozambique, were enrolled. We identified eight exonic and three intronic already described variants. The case/control association analysis highlighted an association between the rs76228616 SNP in exon 2 and the SJS/TEN susceptibility. In particular, the variant allele (C resulted significantly associated with a higher risk to develop SJS/TEN (p = 0.012 and OR = 3.65 (95% CI 1.33–10.01. A multivariate analysis by logistic regression confirmed its significant contribution (p = 0.027, OR = 4.39 (95% CI 1.19–16.23. In conclusion, our study suggests that a variant in TRAF3IP2 gene could be involved in susceptibility to SJS/TEN.

  15. A pharmacogenetics study in Mozambican patients treated with nevirapine: full resequencing of TRAF3IP2 gene shows a novel association with SJS/TEN susceptibility.

    Science.gov (United States)

    Ciccacci, Cinzia; Rufini, Sara; Mancinelli, Sandro; Buonomo, Ersilia; Giardina, Emiliano; Scarcella, Paola; Marazzi, Maria C; Novelli, Giuseppe; Palombi, Leonardo; Borgiani, Paola

    2015-03-12

    Steven-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are severe adverse drug reactions, characterized by extensive epidermal detachment and erosions of mucous membrane. SJS/TEN is one of the most serious adverse reactions to Nevirapine (NVP) treatment, commonly used in developing countries as first-line treatment of human immunodeficiency virus infection. In the last years TRAF3IP2 gene variants had been described as associated with susceptibility to several diseases such as psoriasis and psoriatic arthritis. We hypothesized that this gene, involved in immune response and in NF-κB activation, could also be implicated in the SJS/TEN susceptibility. We performed a full resequencing of TRAF3IP2 gene in a population of patients treated with NVP. Twenty-seven patients with NVP-induced SJS/TEN and 78 controls, all from Mozambique, were enrolled. We identified eight exonic and three intronic already described variants. The case/control association analysis highlighted an association between the rs76228616 SNP in exon 2 and the SJS/TEN susceptibility. In particular, the variant allele (C) resulted significantly associated with a higher risk to develop SJS/TEN (p = 0.012 and OR = 3.65 (95% CI 1.33-10.01)). A multivariate analysis by logistic regression confirmed its significant contribution (p = 0.027, OR = 4.39 (95% CI 1.19-16.23)). In conclusion, our study suggests that a variant in TRAF3IP2 gene could be involved in susceptibility to SJS/TEN.

  16. Early clinical and immune response to NNRTI-based antiretroviral therapy among women with prior exposure to single-dose nevirapine.

    Science.gov (United States)

    Chi, Benjamin H; Sinkala, Moses; Stringer, Elizabeth M; Cantrell, Ronald A; Mtonga, Velepi; Bulterys, Marc; Zulu, Isaac; Kankasa, Chipepo; Wilfert, Catherine; Weidle, Paul J; Vermund, Sten H; Stringer, Jeffrey S A

    2007-05-11

    To determine whether prior exposure to single-dose nevirapine (NVP) for prevention of mother-to-child HIV transmission (PMTCT) is associated with attenuated CD4 cell response, death, or clinical treatment failure in women starting antiretroviral therapy (ART) containing non-nucleoside reverse transcriptase inhibitors (NNRTI). Open cohort evaluation of outcomes for women in program sites across Zambia. HIV treatment was provided according to Zambian/World Health Organization guidelines. Peripartum NVP exposure status was known for 6740 women initiating NNRTI-containing ART, of whom 751 (11%) reported prior use of NVP for PMTCT. There was no significant difference in mean CD4 cell change between those exposed or unexposed to NVP at 6 (+202 versus +182 cells/microl; P = 0.20) or 12 (+201 versus +211 cells/microl; P = 0.60) months. Multivariable analyses showed no significant differences in mortality [adjusted hazard ratio (HR), 1.2; 95% confidence interval (CI), 0.8-1.8] or clinical treatment failure (adjusted HR, 1.1; 95% CI, 0.8-1.5). Comparison of recent NVP exposure with remote exposure suggested a less favorable CD4 cell response at 6 (+150 versus +219 cells/microl; P = 0.06) and 12 (+149 versus +215 cells/microl; P = 0.39) months. Women with recent NVP exposure also had a trend towards elevated risk for clinical treatment failure (adjusted HR, 1.6; 95% CI, 0.9-2.7). Exposure to maternal single-dose NVP was not associated with substantially different short-term treatment outcomes. However, evidence was suggestive that exposure within 6 months of ART initiation may be a risk factor for poor treatment outcomes, highlighting the importance of ART screening and initiation early in pregnancy.

  17. Serum cystatin C predicts vancomycin trough levels better than serum creatinine in hospitalized patients: a cohort study.

    Science.gov (United States)

    Frazee, Erin N; Rule, Andrew D; Herrmann, Sandra M; Kashani, Kianoush B; Leung, Nelson; Virk, Abinash; Voskoboev, Nikolay; Lieske, John C

    2014-05-29

    Serum cystatin C can improve glomerular filtration rate (GFR) estimation over creatinine alone, but whether this translates into clinically relevant improvements in drug dosing is unclear. This prospective cohort study enrolled adults receiving scheduled intravenous vancomycin while hospitalized at the Mayo Clinic in 2012. Vancomycin dosing was based on weight, serum creatinine with the Cockcroft-Gault equation, and clinical judgment. Cystatin C was later assayed from the stored serum used for the creatinine-based dosing. Vancomycin trough prediction models were developed by using factors available at therapy initiation. Residuals from each model were used to predict the proportion of patients who would have achieved the target trough with the model compared with that observed with usual care. Of 173 patients enrolled, only 35 (20%) had a trough vancomycin level within their target range (10 to 15 mg/L or 15 to 20 mg/L). Cystatin C-inclusive models better predicted vancomycin troughs than models based upon serum creatinine alone, although both were an improvement over usual care. The optimal model used estimated GFR by the Chronic Kidney Disease Epidemiology Collaborative (CKD-EPI) creatinine-cystatin C equation (R(2) = 0.580). This model is expected to yield 54% (95% confidence interval 45% to 61%) target trough attainment (P creatinine clearance yielded poor trough achievement. The developed dosing model with estimated GFR from CKD-EPIcreatinine-cystatin C could yield a 2.5-fold increase in target trough achievement compared with current clinical practice. Although this study is promising, prospective validation of this or similar cystatin C-inclusive dosing models is warranted.

  18. Interaction of Kuroshio Current with Global Oceanic and Atmospheric Circulations: Evidences of Grain Size from Okinawa Trough

    Science.gov (United States)

    Wang, J.; Li, A.; Xu, K.; Huang, J.

    2016-12-01

    Okinawa Trough is an ideal place for the study of paleoceanography and paleoenvironment changes. However, the provenances of the sediments and paleoenvironment evolution of the Okinawa Trough have still not been settled yet. Based on grain size, clay minerals and AMS 14C data of the Core OKI03, the provenances and paleoenvironemnt evolution in the middle Okinawa Trough during the last 8 ka were studied. The results indicate that terrigenous sediments deposited in the middle Okinawa Trough were mainly from Yangtze River and Taiwanese rivers since 8 ka. Kuroshio Current (KC), a Western Pacific Ocean boundary current, flows into Okinawa Trough by eastern Taiwan Island, and influences the sediments delivery and distribution within the trough, and also impact the regional and local marine environment in adjacent seas. Statistics study of high resolution grain size in the trough recognizes a millennial-scale oscillation (center around 1800 yr) and a centennial-scale oscillation (center around 512 yr) for KC evolution since last 8 ka. The millennial-scale oscillation is probably related to the North Atlantic Deep Water production with 1400-yr time lag, via the mixing upwelling and impacts on the sea surface temperature (SST) in equatorial Pacific. Meanwhile, the centennial-scale variation possibly corresponds to the solar irradiation with a 240-yr time uncertainty, through the SST change. KC possible influences the climate and North Atlantic Deep Water formation by transferring heat to the atmosphere in high latitude of Pacific Ocean, and also interacts with the thermohaline circulation by transferring heat to Indian Ocean through North Pacific Intermediate Water.

  19. Thermal and chemical variations of the Nigerian Benue trough lead-zinc-barite-fluorite deposits

    Science.gov (United States)

    Ogundipe, Ibukun Emmanuel

    2017-08-01

    The Benue trough is an intra-continental rift initiated in the Cretaceous during the opening of the South Atlantic Ocean. Lead-zinc-barite-fluorite mineralization occurs along the 600 km axis of the trough in three discrete sub-basins which coincide with the lower, middle and upper mineral districts of the Benue Valley. Lithologically these sub-basins are dominated by black carbonaceous shale in the Lower Benue, platform carbonates in the Middle Benue and sandstones in the Upper Benue. Micro-thermometric analysis of fluid inclusions in sphalerite, fluorite, barite and quartz have shown that each mineral district has its own unique thermal and chemical imprint. For example, the temperature can be bracketed between 109 °C and 160 °C for lower Benue, 89 °C-144 °C for the Middle Benue and 176 °C-254 °C for the Upper Benue. Chemical differentiation also exists between each mineral district with the Lower Benue having 22 wt % equivalent NaCl while the Middle and Upper Benue have 18 and 16 wt % equivalent NaCl respectively. This study shows that inter-district thermal and chemical variations exist between the ore-stage sulfide and post-sulfide gangue minerals of the entire Benue Valley. Similarly, intra-district thermal and chemical variations have also been observed among all the paragenetic minerals of each district. The thermal variations may be as a result of variations in the geothermal gradient accompanying continental rifting from one district to the other. The variations in the chemistry between the Lower Benue and the Upper Benue paragenic minerals may be as a result of the distinct lithological differences across the Benue Trough.

  20. The Salton Seismic Imaging Project: Investigating Earthquake Hazards in the Salton Trough, Southern California

    Science.gov (United States)

    Fuis, G. S.; Goldman, M.; Sickler, R. R.; Catchings, R. D.; Rymer, M. J.; Rose, E. J.; Murphy, J. M.; Butcher, L. A.; Cotton, J. A.; Criley, C. J.; Croker, D. S.; Emmons, I.; Ferguson, A. J.; Gardner, M. A.; Jensen, E. G.; McClearn, R.; Loughran, C. L.; Slayday-Criley, C. J.; Svitek, J. F.; Hole, J. A.; Stock, J. M.; Skinner, S. M.; Driscoll, N. W.; Harding, A. J.; Babcock, J. M.; Kent, G.; Kell, A. M.; Harder, S. H.

    2011-12-01

    The Salton Seismic Imaging Project (SSIP) is a collaborative effort between academia and the U.S. Geological Survey to provide detailed, subsurface 3-D images of the Salton Trough of southern California and northern Mexico. From both active- and passive-source seismic data that were acquired both onshore and offshore (Salton Sea), the resulting images will provide insights into earthquake hazards, rift processes, and rift-transform interaction at the southern end of the San Andreas Fault system. The southernmost San Andreas Fault (SAF) is considered to be at high-risk of producing a large damaging earthquake, yet the structure of this and other regional faults and that of adjacent sedimentary basins is not currently well understood. Seismic data were acquired from 2 to 18 March 2011. One hundred and twenty-six borehole explosions (10-1400 kg yield) were detonated along seven profiles in the Salton Trough region, extending from area of Palm Springs, California, to the southwestern tip of Arizona. Airguns (1500 and 3500 cc) were fired along two profiles in the Salton Sea and at points in a 2-D array in the southern Salton Sea. Approximately 2800 seismometers were deployed at over 4200 locations throughout the Salton Trough region, and 48 ocean-bottom seismometers were deployed at 78 locations beneath the Salton Sea. Many of the onshore explosions were energetic enough to be recorded and located by the Southern California Seismograph Network. The geometry of the SAF has important implications for energy radiation in the next major rupture. Prior potential field, seismicity, and InSAR data indicate that the SAF may dip moderately to the northeast from the Salton Sea to Cajon Pass in the Transverse Ranges. Much of SSIP was designed to test models of this geometry.

  1. LCOE reduction potential of parabolic trough and solar tower CSP technology until 2025

    Science.gov (United States)

    Dieckmann, Simon; Dersch, Jürgen; Giuliano, Stefano; Puppe, Michael; Lüpfert, Eckhard; Hennecke, Klaus; Pitz-Paal, Robert; Taylor, Michael; Ralon, Pablo

    2017-06-01

    Concentrating Solar Power (CSP), with an installed capacity of 4.9 GW by 2015, is a young technology compared to other renewable power generation technologies. A limited number of plants and installed capacity in a small challenging market environment make reliable and transparent cost data for CSP difficult to obtain. The International Renewable Energy Agency (IRENA) and the DLR German Aerospace Center gathered and evaluated available cost data from various sources for this publication in order to yield transparent, reliable and up-to-date cost data for a set of reference parabolic trough and solar tower plants in the year 2015 [1]. Each component of the power plant is analyzed for future technical innovations and cost reduction potential based on current R&D activities, ongoing commercial developments and growth in market scale. The derived levelized cost of electricity (LCOE) for 2015 and 2025 are finally contrasted with published power purchase agreements (PPA) of the NOOR II+III power plants in Morocco. At 7.5% weighted average cost of capital (WACC) and 25 years economic life time, the levelized costs of electricity for plants with 7.5 (trough) respectively 9 (tower) full-load hours thermal storage capacity decrease from 14-15 -ct/kWh today to 9-10 -ct/kWh by 2025 for both technologies at direct normal irradiation of 2500 kWh/(m².a). The capacity factor increases from 41.1% to 44.6% for troughs and from 45.5% to 49.0% for towers. Financing conditions are a major cost driver and offer potential for further cost reduction with the maturity of the technology and low interest rates (6-7 - ct/kWh for 2% WACC at 2500 kWh/(m2.a) in 2025).

  2. Multi-Scale Peak and Trough Detection Optimised for Periodic and Quasi-Periodic Neuroscience Data.

    Science.gov (United States)

    Bishop, Steven M; Ercole, Ari

    2018-01-01

    The reliable detection of peaks and troughs in physiological signals is essential to many investigative techniques in medicine and computational biology. Analysis of the intracranial pressure (ICP) waveform is a particular challenge due to multi-scale features, a changing morphology over time and signal-to-noise limitations. Here we present an efficient peak and trough detection algorithm that extends the scalogram approach of Scholkmann et al., and results in greatly improved algorithm runtime performance. Our improved algorithm (modified Scholkmann) was developed and analysed in MATLAB R2015b. Synthesised waveforms (periodic, quasi-periodic and chirp sinusoids) were degraded with white Gaussian noise to achieve signal-to-noise ratios down to 5 dB and were used to compare the performance of the original Scholkmann and modified Scholkmann algorithms. The modified Scholkmann algorithm has false-positive (0%) and false-negative (0%) detection rates identical to the original Scholkmann when applied to our test suite. Actual compute time for a 200-run Monte Carlo simulation over a multicomponent noisy test signal was 40.96 ± 0.020 s (mean ± 95%CI) for the original Scholkmann and 1.81 ± 0.003 s (mean ± 95%CI) for the modified Scholkmann, demonstrating the expected improvement in runtime complexity from [Formula: see text] to [Formula: see text]. The accurate interpretation of waveform data to identify peaks and troughs is crucial in signal parameterisation, feature extraction and waveform identification tasks. Modification of a standard scalogram technique has produced a robust algorithm with linear computational complexity that is particularly suited to the challenges presented by large, noisy physiological datasets. The algorithm is optimised through a single parameter and can identify sub-waveform features with minimal additional overhead, and is easily adapted to run in real time on commodity hardware.

  3. Interaction of Structure and Physical Properties in Accretionary Wedges: Examples from the Cascadia and Nankai Trough Subduction Zones

    Science.gov (United States)

    Webb, Susanna I.

    Subduction zones are capable of producing large, megathrust earthquakes that are sometimes tsunamigenic. Structure and physical properties in the accretionary wedge play a role in how far rupture can propagate and how the wedge deforms coseismically. In this dissertation, I use seismic reflection data and velocity models from the Cascadia subduction zone and logging data from the Nankai Trough, Japan, to interpret structure, link structure to the broader wedge deformation history, and investigate the material properties at depth. I present a full structural interpretation of newly acquired seismic reflection data in the central Cascadia margin, which is characterized by dominantly landward vergent faulting in the outer wedge, a very low wedge taper angle, and a broad, lightly deformed lower slope terrace. Two decollements are active: an upper decollement within the sedimentary section, and a basal decollement at the sediment-basement interface. These interpretations help delineate the spatial extent of decollements and suggest that supra-wedge sedimentation may influence the development of the wedge, including the formation of the lower slope terrace and out of sequence fault activity. I use velocity models from central Cascadia to estimate excess pore fluid pressure and overpressure ratio at depth, which do not exceed 5 MPa and 0.15, respectively. No excess pore pressure is documented in the underthrust sediment section, but modest overpressure is likely present in the incoming sediment section and the footwalls of thrust sheets. The analysis of pore pressure shows that (1) if the base of the wedge is weak, it is due to mechanical properties of the sediments or a relatively thin underthrust layer and (2) the Cascadia wedge is relatively well-drained, and thus potentially strong, which can lead to a low wedge taper angle. In the Nankai Trough, Japan, I reprocessed sonic log data to obtain P-wave and S-wave velocity values and estimate elastic moduli. The logs

  4. Object-oriented simulation model of a parabolic trough solar collector: Static and dynamic validation

    Science.gov (United States)

    Ubieta, Eduardo; Hoyo, Itzal del; Valenzuela, Loreto; Lopez-Martín, Rafael; Peña, Víctor de la; López, Susana

    2017-06-01

    A simulation model of a parabolic-trough solar collector developed in Modelica® language is calibrated and validated. The calibration is performed in order to approximate the behavior of the solar collector model to a real one due to the uncertainty in some of the system parameters, i.e. measured data is used during the calibration process. Afterwards, the validation of this calibrated model is done. During the validation, the results obtained from the model are compared to the ones obtained during real operation in a collector from the Plataforma Solar de Almeria (PSA).

  5. Prospecting for a Blind Geothermal System Utilizing Geologic and Geophysical Data, Seven Troughs Range, Northwestern Nevada

    Science.gov (United States)

    Forson, Corina

    To aid in the discovery and evaluation of blind resources, it is important to utilize geologic, geophysical, and geochemical techniques to find the required elements (e.g., heat source, fluid to transport the heat, and permeability in a reservoir) for geothermal energy production. Based on a regional low resistivity anomaly discovered through a reconnaissance magnetotelluric (MT) survey, detailed geologic mapping, structural analysis, and a 2 m temperature survey were conducted to delineate the most likely areas for blind geothermal activity in the Seven Troughs Range, Nevada. The Seven Troughs Range resides in the northwestern Basin and Range province 190 km northeast of Reno and 50 km northwest of Lovelock in western Nevada. There is no known geothermal system in the area. Mesozoic metasedimentary strata and intrusions dominate the northern and southern parts of the range but are nonconformably overlain by a thick sequence (~ 1.5 km) of Oligocene to Miocene volcanic and volcaniclastic rocks and Quaternary sediments in the central part of the range. The southern part of the range consists of a basement horst block bounded by two major range-front faults, with Holocene fault scarps marking the more prominent fault on the east side of the range. In contrast, several gently to moderately west-tilted fault blocks, with good exposures of the Tertiary volcanic strata and bounded by a series of steeply east-dipping normal faults, characterize the central part of the range. Kinematic analysis of faults in the range and regional relations indicate a west-northwest-trending extension direction. Accordingly, slip and dilation tendency analyses suggest that north-northeast striking faults are the most favorably oriented for reactivation and fluid flow under the current stress field. Two areas in the Seven Troughs Range have a favorable structural setting for generating permeability and channeling geothermal fluids to the near surface: 1) A major right step in the range

  6. Morphotectonics of the central Muertos thrust belt and Muertos Trough (northeastern Caribbean)

    Science.gov (United States)

    Granja, Bruna J.L.; ten Brink, Uri S.; Carbó-Gorosabel, Andrés; Muñoz-Martín, A.; Gomez, Ballesteros M.

    2009-01-01

    Multibeam bathymetry data acquired during the 2005 Spanish R/V Hesp??rides cruise and reprocessed multichannel seismic profiles provide the basis for the analysis of the morphology and deformation in the central Muertos Trough and Muertos thrust belt. The Muertos Trough is an elongated basin developed where the Venezuelan Basin crust is thrusted under the Muertos fold-and-thrust belt. Structural variations along the Muertos Trough are suggested to be a consequence of the overburden of the asymmetrical thrust belt and by the variable nature of the Venezuelan Basin crust along the margin. The insular slope can be divided into three east-west trending slope provinces with high lateral variability which correspond to different accretion stages: 1) The lower slope is composed of an active sequence of imbricate thrust slices and closed fold axes, which form short and narrow accretionary ridges and elongated slope basins; 2) The middle slope shows a less active imbricate structure resulting in lower superficial deformation and bigger slope basins; 3) The upper slope comprises the talus region and extended terraces burying an island arc basement and an inactive imbricate structure. The talus region is characterized by a dense drainage network that transports turbidite flows from the islands and their surrounding carbonate platform areas to the slope basins and sometimes to the trough. In the survey area the accommodation of the ongoing east-west differential motion between the Hispaniola and the Puerto Rico-Virgin Islands blocks takes place by means of diffuse deformation. The asymmetrical development of the thrust belt is not related to the geological conditions in the foreland, but rather may be caused by variations in the geometry and movement of the backstop. The map-view curves of the thrust belt and the symmetry of the recesses suggest a main north-south convergence along the Muertos margin. The western end of the Investigator Fault Zone comprises a broad band of

  7. Manic-Like Psychosis Associated with Elevated Trough Tacrolimus Blood Concentrations 17 Years after Kidney Transplant

    Directory of Open Access Journals (Sweden)

    Giuseppe Bersani

    2013-01-01

    Full Text Available Several neurological side effects induced by tacrolimus are described in the scientific literature, ranging from mild neurological symptoms to delirium and psychosis. We report the case of a 46-year-old man with no prior psychiatric history who suddenly manifested manic-like psychosis associated with elevated trough tacrolimus blood concentrations 17 years after kidney transplant. The use of antipsychotics may improve the severity of symptoms; but in order to obtain a complete remission, the reduction in the dose of tacrolimus, or its replacement with alternative immunosuppressant therapies, is recommended.

  8. Relative bioavailability of two formulations of nevirapine 200-mg tablets in healthy Chinese male volunteers: a single-dose, randomized-sequence, open-label, two-way crossover study.

    Science.gov (United States)

    Zhu, Yubing; Zhang, Qian; Yu, Cuixia; Zou, Jianjun; Yang, Xiaohong; Hu, Yunfang

    2010-12-01

    Nevirapine was the first member of the nonnucleoside reverse transcriptase inhibitor class to be approved for the treatment of HIV infection. It binds directly to the allosteric site on the reverse transcriptase and inhibits the activity of both RNA- and DNA-dependent DNA polymerases. This study compared the pharmacokinetics and relative bioavailability of a test and reference formulation of nevirapine 200-mg tablets after single oral doses in healthy Chinese men to meet regulatory criteria for marketing of the new generic formulation. This single-dose, randomized-sequence, open-label, 2-way crossover study was conducted at the Nanjing First Hospital of Nanjing Medical University, Nanjing, China. Healthy male Chinese volunteers were randomized in a 1∶1 ratio to receive a single 200-mg (3.2-mg/kg) tablet of the test or reference formulation, followed by a 2-week washout period and administration of the alternate formulation. The study drugs were administered after a 10-hour overnight fast. Concentrations of nevirapine were assayed using an HPLC-UV method. For analysis of nevirapine pharmacokinetic parameters, blood samples were obtained before dosing and at regularly scheduled intervals over 168 hours after administration. The 2 formulations would be assumed to be bioequivalent for regulatory purposes if the 90% CIs for the log-transformed ratios of nevirapine AUC and C(max) were within the range established by the US Food and Drug Administration (0.80-1.25). Tolerability was evaluated throughout the study based on vital signs, physical examinations, 12-lead ECGs, and subject interviews concerning adverse events (AEs). Twenty Chinese male subjects were enrolled in and completed the study. Their mean age was 23 years (range, 21-25 years), mean weight was 63 kg (range, 56-70 kg), and mean height was 171 cm (range, 166-176 cm). No period or sequence effect was observed. The mean (SD) t(½) was 38.12 (2.23) hours for the test tablet and 36.79 (5.06) hours for the

  9. Experimental validation of energy parameters in parabolic trough collector with plain absorber and analysis of heat transfer enhancement techniques

    Science.gov (United States)

    Bilal, F. R.; Arunachala, U. C.; Sandeep, H. M.

    2018-01-01

    The quantum of heat loss from the receiver of the Parabolic Trough Collector is considerable which results in lower thermal efficiency of the system. Hence heat transfer augmentation is essential which can be attained by various techniques. An analytical model to evaluate the system with bare receiver performance was developed using MATLAB. The experimental validation of the model resulted in less than 5.5% error in exit temperature using both water and thermic oil as heat transfer fluid. Further, heat transfer enhancement techniques were incorporated in the model which included the use of twisted tape inserts, nanofluid, and a combination of both for further enhancement. It was observed that the use of evacuated glass cover in the existing setup would increase the useful heat gain up to 5.3%. Fe3O4/H2O nanofluid showed a maximum enhancement of 56% in the Nusselt number for the volume concentration of 0.6% at highest Reynolds number. Similarly, twisted tape turbulators (with twist ratio of 2) taken alone with water exhibited 59% improvement in Nusselt number. Combining both the heat transfer augmentation techniques at their best values revealed the Nusselt number enhancement up to 87%. It is concluded that, use of twisted tape with water is the best method for heat transfer augmentation since it gives the maximum effective thermal efficiency amongst all for the range of Re considered. The first section in your paper

  10. Ambient Noise Tomography of Southern California Images Dipping San Andreas-Parallel Structure and Low-Velocity Salton Trough Mantle

    Science.gov (United States)

    Barak, S.; Klemperer, S. L.; Lawrence, J. F.

    2014-12-01

    Ambient noise tomography (ANT) images the entire crust but does not depend on the spatial and temporal distribution of events. Our ANT high-resolution 3D velocity model of southern California uses 849 broadband stations, vastly more than previous studies, and four years of data, 1997-1998, 2007, and 2011, chosen to include our own broadband Salton Seismic Imaging Project, a 40-station transect across the Salton Trough, as well as other campaign stations in both Mexico and the U.S.A., and permanent stations. Our shear-wave model has 0.05° x 0.05° lateral and 1 km vertical blocks. We used the Harvard Community Velocity Model (CVM-H) as the initial model for the inversion. We show significant differences relative to the CVM-H model, especially in the lower crust and upper mantle. We observe prominent low-velocity anomalies in the upper mantle under the Salton Buttes and Cerro Prieto geothermal fields, indicating high-temperatures and possibly partial-melt. Similar low-velocity zones have been previously observed along the Gulf of California. We also observe vertical to gradually dipping lateral velocity contrasts in the lower crust under the southern part of the San Andreas Fault. The east to northeast dip may represent crustal fabric sheared by movement of the Pacific plate under the North American plate prior to the initiation of transform motion.

  11. Relation between methane hydrate-bearing formations and geological phenomena on the seafloor in the eastern Nankai trough

    Energy Technology Data Exchange (ETDEWEB)

    Nagakubo, S.; Kobayashi, T.; Inamori, T.; Saeki, T.; Shimoda, N.; Fujii, T. [Japan Oil, Gas and Metals National Corp., Chiba (Japan). Technology Research Center; Morita, S.; Tanahashi, M. [National Inst. of Advanced Industrial Science and Technology, Tsukuba (Japan). Inst. for Geo-Resources and Environment

    2008-07-01

    Bathymetric and sea floor amplitude maps of the Tokai-Oki area, Daini-Atsumi Knoll, and Kumao-Nada areas were constructed using data obtained from 3-D seismic surveys. The study examined the control factors of fluid migration between methane hydrate formations and the sea floor. The aim of the study was to understand the relationship between methane hydrate-bearing formation and geological phenomena in the eastern Nankai trough. Sea floor geological features in the region include canyons, pockmarks, landslides, and undulations. The study identified methane seeps with biological colonies, bacteria mats and methane-enriched pore water. Strong sea floor amplitudes corresponded with distributions of carbonate outcrops and methane-bearing fluids around the BSR. The study showed that the principle geological control factors for fluid migration between methane hydrate-bearing formations and the sea floor are permeable sandy sediments; shallow faults; and natural hydraulic fractures. Significant shallow anomalies were observed in the Daini-Atsumi Knoll area. Sandy sediments derived from turbidites control the distributions of bottom simulating reflectors. It was concluded that permeable sandy sediments may play an important role in fluid migration between methane hydrate-bearing formations and the sea floor. 12 refs., 13 figs.

  12. Spectrum-splitting hybrid CSP-CPV solar energy system with standalone and parabolic trough plant retrofit applications

    Science.gov (United States)

    Orosz, Matthew; Zweibaum, Nicolas; Lance, Tamir; Ruiz, Maritza; Morad, Ratson

    2016-05-01

    Sunlight to electricity efficiencies of Parabolic Trough Collector (PTC) plants are typically on the order of 15%, while commercial solar Photovoltaic (PV) technologies routinely achieve efficiencies of greater than 20%, albeit with much higher conversion efficiencies of photons at the band gap. Hybridizing concentrating solar power and photovoltaic technologies can lead to higher aggregate efficiencies due to the matching of photons to the appropriate converter based on wavelength. This can be accomplished through spectral filtering whereby photons unusable or poorly utilitized by PV (IR and UV) are passed through to a heat collection element, while useful photons (VIS) are reflected onto a concentrating PV (CPV) receiver. The mechanical design and experimental validation of spectral splitting optics is described in conjunction with system level modeling and economic analysis. The implications of this architecture include higher efficiency, lower cost hybrid CSP-PV power systems, as well as the potential to retrofit existing PTC plants to boost their output by ~ 10% at a projected investment cost of less than 1 per additional net Watt and an IRR of 18%, while preserving the dispatchability of the CSP plant's thermal energy storage.

  13. Initial dose of vancomycin based on body weight and creatinine clearance to minimize inadequate trough levels in Japanese adults.

    Science.gov (United States)

    Maki, N; Ohkuchi, A; Tashiro, Y; Kim, M R; Le, M; Sakamoto, T; Matsubara, S; Hakamata, Y

    2012-10-01

    Our aims were to elucidate the factors that affected vancomycin (VCM) serum trough levels and to find the optimal initial dose based on creatinine clearance (CrCl) and body weight (BW) to minimize inadequate trough levels in a retrospective observational study among Japanese adults. One hundred and six inpatients, in whom VCM trough levels were measured after completing the third dosing, were consecutively recruited into our study in a tertiary hospital. We considered the frequency of initial VCM total daily dose, CrCl, and BW were independent risk factors of VCM trough levels. In patients with CrCl ≥30 and level of ≥20 mcg/mL, regardless of BW. In patients with CrCl ≥50 mL/min, 2 g/day yielded low frequencies of a trough level of initial total daily dose may be 1 g/day in patients with CrCl ≥30 and <50 mL/min regardless of BW and 2 g/day in patients weighing <55 kg with CrCl ≥50 mL/min among Japanese adults.

  14. Influence of climate on deep-water clastic sedimentation: application of a modern model, Peru-Chile Trough, to an ancient system, Ouachita Trough

    Science.gov (United States)

    Edgar, N. Terence; Cecil, C. Blaine

    2003-01-01

    Traditionally, an abrupt and massive influx of siliciclastic sediments into an area of deposition has been attributed to tectonic uplift without consideration of the influence of climate or climatic change on rates of weathering, erosion, transportation, and deposition. With few exceptions, fluvial sediment transport is minimal in both extremely arid climates and in perhumid (everwet) climates. Maximum sediment transport occurs in climates characterized by strongly seasonal rainfall, where the effect of vegetation on erosion is minimal. The Peru–Chile trench and Andes Mountain system (P–CT/AMS) of the eastern Pacific Ocean clearly illustrates the effects of climate on rates of weathering, erosion, transport, and deep-sea sedimentation. Terrigenous sediment is virtually absent in the arid belt north of lat. 30° S in the P–CT, but in the belt of seasonal rainfall south of lat. 30° S terrigenous sediment is abundant. Spatial variations in the amount and seasonality of annual precipitation are now generally accepted as the cause for this difference. The spatial variation in sediment supply to the P–CT appears to be an excellent modern analogue for the temporal variation in sediment supply to certain ancient systems, such as the Ouachita Trough in the southern United States. By comparison, during the Ordovician through the early Mississippian, sediment was deposited at very slow rates as the Ouachita Trough moved northward through the southern hemisphere dry belt (lat. 10° S to lat. 30° S). The deposystem approached the tropical humid zone during the Mississippian, coincident with increased coarse clastic sedimentation. By the Middle Pennsylvanian (Atokan), the provenance area and the deposystem moved well into the tropical humid zone, and as much as 8,500 m of mineralogically mature (but texturally immature) quartz sand was introduced and deposited. This increase in clastic sediment deposition traditionally has been attributed solely to tectonic activity

  15. Methane hydrate reservoir model around the eastern Nankai trough area offshore Japan

    Energy Technology Data Exchange (ETDEWEB)

    Inamori, T.; Hayashi, M.; Kobayashi, T.; Shimoda, N.; Takano, O.; Takayama, T.; Fujii, T.; Saeki, T. [Japan Oil, Gas and Metals National Corp., Chiba (Japan). Dept. of Technology Research and Development

    2008-07-01

    This paper described a modelling study conducted to characterize gas hydrates in the eastern Nankai trough region near the coast of Japan. Two drilling campaigns were conducted in the region, and a total of 39 boreholes were drilled to obtain logging data. Data from exploratory wells drilled in the region were also presented. Methane hydrate-concentrated zones were delineated using seismic sequence analysis and 3-D seismic surveys. Methane hydrate-bearing sediments corresponded with turbidite sands using logging and coring data. A rock physics model was developed using data obtained from the analyses. The study showed that methane hydrate bearing-sediments near the eastern Nankai trough area are heterogenous and both vertically and horizontally complex, as the sediments were composed of turbidite sands with channel-levee and lobe systems. Sandy intervals had higher levels of methane hydrates than silty or muddy intervals. The reservoirs were divided into 3 distinct types: (1) low-saturation; (2) discontinuous high-saturation; and (3) continuous high-saturation. The reservoirs were delineated by selecting the bottom simulating reflector (BSM) as the top of the hydrate-bearing sediments for the turbidite channel-levee or lobe systems. The hydrate rock physics model was used to develop the matrix support model from the relationship between P and S wave velocities and methane hydrate saturation. 9 refs., 11 figs.

  16. 2D multi-component survey over methane hydrate deposits in the Nankai Trough

    Energy Technology Data Exchange (ETDEWEB)

    Ward, P.; Asakawa, E.; Allawati, H. [JGI Inc., Bunkyo-ku, Tokyo (Japan); Saeki, T.; Inamori, T.; Shimoda, N. [Japan Oil, Gas and Metals National Corp., Mihama-ku, Chiba (Japan). Technology Research Center

    2008-07-01

    A 2D real-time seismic cable system (RSCS) survey was conducted near the edge of the Nankai Trough offshore Japan in December 2006. The objectives were to obtain high quality P-wave seismic sections and S-wave characteristics of a methane hydrate deposit in the Nankai Trough. C-waves (PS converted waves) with multicomponent sensors were used to delineate the elastic properties. The 3 component data was acquired on the sea bed over 2 well locations and part of a conventional streamer 3D survey. Of the 3 receiver lines, the first intersected the 4 well locations with 4 deployments of RSCS, while the second and third lines crossed the first line at each well location with 1 and 2 deployments. A sea-surface airgun system was used as a source with a spacing of 25 m. P-wave OBS pre-stack migration was used to image the vertical component data. C-Wave OBS pre-stack migration was used to image the in-line horizontal component data. Amplitude anomalies at the BSR level were detected in the C-wave sections, which indicates S-wave anomaly. The authors suggested that this information may be useful in estimating the rock physics model of the methane hydrates in this area. 5 refs., 11 figs.

  17. Harmonization of standards for parabolic trough collector testing in solar thermal power plants

    Science.gov (United States)

    Sallaberry, Fabienne; Valenzuela, Loreto; Palacin, Luis G.; Leon, Javier; Fischer, Stephan; Bohren, Andreas

    2017-06-01

    The technology of parabolic trough collectors (PTC) is used widely in concentrating Solar Power (CSP) plants worldwide. However this type of large-size collectors cannot be officially tested by an accredited laboratory and certified by an accredited certification body so far, as there is no standard adapted to its particularity, and the current published standard for solar thermal collectors are not completely applicable to them. Recently some standardization committees have been working on this technology. This paper aims to give a summary of the standardized testing methodology of large-size PTC for CSP plants, giving the physical model chosen for modeling the thermal performance of the collector in the new revision of standard ISO 9806 and the points still to be improved in the standard draft IEC 62862-3-2. In this paper, a summary of the testing validation performed on one parabolic trough collector installed in one of the test facilities at the Plataforma Solar de Almería (PSA) with this new model is also presented.

  18. A model of the perceptual asymmetry between peaks and troughs of frequency modulation.

    Science.gov (United States)

    de Cheveigné, A

    2000-05-01

    Pitch discrimination at peaks of frequency modulation is better than at troughs [L. Demany and K. I. McAnally, J. Acoust. Soc. Am. 96, 706-715 (1989)]. A similar asymmetry emerges within a time-domain pitch perception model based on autocorrelation. The model requires the following assumptions: (a) The neural discharge patterns must be temporally sharpened to a single narrow pulse per period (possibly by neural convergence within the cochlear nucleus). (b) Autocorrelation must be implemented as a cross correlation between the neural pulse train and a delayed pulse train convolved with a short kernel function. This kernel function must be asymmetric in time. (c) Pitch discrimination must rely on higher-order modes of the autocorrelation function. This particular implementation of the autocorrelation model produces modes that are sharper for peaks than for troughs, and thus accounts for the pitch discrimination asymmetry observed experimentally. As a by-product it can account for "hyperacute" discrimination observed at peaks of triangular modulation.

  19. Performance Evaluation of a Nanofluid-Based Direct Absorption Solar Collector with Parabolic Trough Concentrator

    Directory of Open Access Journals (Sweden)

    Guoying Xu

    2015-12-01

    Full Text Available Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the coating can lead to an increased manufacturing cost and unreliability for a solar collector operated at a higher temperature. Therefore, a novel nanofluid-based direct absorption solar collector (NDASC employing uncoated collector tubes has been proposed, and its operating characteristics for medium-temperature solar collection were theoretically and experimentally studied in this paper. CuO/oil nanofluid was prepared and used as working fluid of the NDASC. The heat-transfer mechanism of the NDASC with parabolic trough concentrator was theoretically evaluated and compared with a conventional indirect absorption solar collector (IASC. The theoretical analysis results suggested that the fluid’s temperature distribution in the NDASC was much more uniform than that in the IASC, and an enhanced collection efficiency could be achieved for the NDASC operated within a preferred working temperature range. To demonstrate the feasibility of the proposed NDASC, experimental performances of an NDASC and an IASC with the same parabolic trough concentrator were furthermore evaluated and comparatively discussed.

  20. NanTroSEIZE: The IODP Nankai Trough Seismogenic Zone Experiment

    Directory of Open Access Journals (Sweden)

    Harold J. Tobin

    2006-03-01

    Full Text Available The IODP Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE will, for the fi rst time ever, attempt to drill into, sample, and instrument the seismogenic portion of a plate-boundary fault or megathrust within a subduction zone. Access to the interior of active faults where in situ processes can be monitored and fresh fault zone materials can be sampled is of fundamental importance to the understanding of earthquake mechanics. As the December 2004 Sumatraearthquake and Indian Ocean tsunami so tragically demonstrated,large subduction earthquakes represent one of the greatest natural hazards on the planet. Accordingly, drilling into and instrumenting an active interplate seismogenic zone is a very high priority in the IODP Initial Science Plan (2001. Through a decade-long series of national and international workshops, a consensus emerged that the Nankai Trough is an ideal place to attempt drilling and monitoring of the seismogenic plate interface. The fi rst phase of NanTroSEIZE drilling operations has now been scheduled for the late summer of 2007. It involves parallel deployment of both the new U.S. Scientifi c Ocean Drilling Vessel (SODV, this volume and the riser drilling vessel Chikyu.

  1. Sensitive Analysis for the Efficiency of a Parabolic Trough Solar Collector Based on Orthogonal Experiment

    Directory of Open Access Journals (Sweden)

    Xiaoyan Liu

    2015-01-01

    Full Text Available A multitude of the researches focus on the factors of the thermal efficiency of a parabolic trough solar collector, that is, the optical-thermal efficiency. However, it is limited to a single or double factors for available system. The aim of this paper is to investigate the multifactors effect on the system’s efficiency in cold climate region. Taking climatic performance into account, an average outlet temperature of LS-2 collector has been simulated successfully by coupling SolTrace software with CFD software. Effects of different factors on instantaneous efficiency have been determined by orthogonal experiment and single factor experiment. After that, the influence degree of different factors on the collector instantaneous efficiency is obtained clearly. The results show that the order of effect extent for average maximal deviation of each factor is inlet temperature, solar radiation intensity, diameter, flow rate, condensation area, pipe length, and ambient temperature. The encouraging results will provide a reference for the exploitation and utilization of parabolic trough solar collector in cold climate region.

  2. Organic geochemical characterization of potential hydrocarbon source rocks in the upper Benue Trough

    International Nuclear Information System (INIS)

    Obaje, N. G.; Pearson, M. J.; Suh, C. E.; Dada, S. S.

    1999-01-01

    The Upper Benue Trough of Nigeria is the northeastern most portion of the Benue rift structure that extends from the northern limit of the Niger Delta in the south to the southern limit of the Chad basin int he northeast. this portion of the trough is made up of two arms: the Gongola Arm and the Yola Arm. Stratigraphic sequence in the Gongola Arm comprises the continental Albian Bima Sandstone, the transitional Cenomanian Yolde Formation and the marine Turonian - Santonian Gongila, Pindiga, and Fika Formations. Overlying these are the continental Campane - Maastrichtian Gombe Sandstone and the Tertiary Kerri - Kerri Formation. In the Yola Arm, the Turonian - Santonian sequence is replaced by the equally marine Dukul, Jessu, Sekuliye Formations, Numanha Shale, and the Lamja Sandstone. Organic geochemical studies have been carried on outcrop sample form the Gongila, Pindiga, Dukul Formations, the Fika shale and the shaly units of the Gombe Sandstone, with the aim of assessing their source rock potential. Gas Chromatography (GC), Gas Chromatography - Mass Spectrometry (C - MS), and Rock Eval Pyrolysis were the major organic geochemical tools employed. Biomaker hydrocarbon signatures obtained from the GC - MS and the Rock Eval Pyrolysis results indicate that all he formations studied, except the Dukul formation, are immature and are all lean in organic matter

  3. A Novel Parabolic Trough Concentrating Solar Heating for Cut Tobacco Drying System

    Directory of Open Access Journals (Sweden)

    Jiang Tao Liu

    2014-01-01

    Full Text Available A novel parabolic trough concentrating solar heating for cut tobacco drying system was established. The opening width effect of V type metal cavity absorber was investigated. A cut tobacco drying mathematical model calculated by fourth-order Runge-Kutta numerical solution method was used to simulate the cut tobacco drying process. And finally the orthogonal test method was used to optimize the parameters of cut tobacco drying process. The result shows that the heating rate, acquisition factor, and collector system efficiency increase with increasing the opening width of the absorber. The simulation results are in good agreement with experimental data for cut tobacco drying process. The relative errors between simulated and experimental values are less than 8%, indicating that this mathematical model is accurate for the cut tobacco airflow drying process. The optimum preparation conditions are an inlet airflow velocity of 15 m/s, an initial cut tobacco moisture content of 26%, and an inlet airflow temperature of 200°C. The thermal efficiency of the dryer and the final cut tobacco moisture content are 66.32% and 14.15%, respectively. The result shows that this parabolic trough concentrating solar heating will be one of the heat recourse candidates for cut tobacco drying system.

  4. Water Use in Parabolic Trough Power Plants: Summary Results from WorleyParsons' Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, C. S.; Wagner, M. J.; Kutscher, C. F.

    2010-12-01

    The National Renewable Energy Laboratory (NREL) contracted with WorleyParsons Group, Inc. to examine the effect of switching from evaporative cooling to alternative cooling systems on a nominal 100-MW parabolic trough concentrating solar power (CSP) plant. WorleyParsons analyzed 13 different cases spanning three different geographic locations (Daggett, California; Las Vegas, Nevada; and Alamosa, Colorado) to assess the performance, cost, and water use impacts of switching from wet to dry or hybrid cooling systems. NREL developed matching cases in its Solar Advisor Model (SAM) for each scenario to allow for hourly modeling and provide a comparison to the WorleyParsons results.Our findings indicate that switching from 100% wet to 100% dry cooling will result in levelized cost of electricity (LCOE) increases of approximately 3% to 8% for parabolic trough plants throughout most of the southwestern United States. In cooler, high-altitude areas like Colorado's San Luis Valley, WorleyParsons estimated the increase at only 2.5%, while SAM predicted a 4.4% difference. In all cases, the transition to dry cooling will reduce water consumption by over 90%. Utility time-of-delivery (TOD) schedules had similar impacts for wet- and dry-cooled plants, suggesting that TOD schedules have a relatively minor effect on the dry-cooling penalty.

  5. Vertical Cable Seismic (VCS) Survey for SMS exploration in Izena Cauldron, Okinawa-Trough

    Science.gov (United States)

    Asakawa, Eiichi; Murakami, Fumitoshi; Tsukahara, Hitoshi; Mizohata, Shigeharu; Tara, Kenji

    2015-04-01

    In 2014, the Japanese government started the Cross-ministerial Strategic Innovation Promotion Program (SIP), which includes 'New-generation Offshore Exploration Techniques' as an area of interest. We proposed the Vertical Cable Seismic (VCS) survey technique for this program, especially for the exploration of Seafloor Massive Sulfides (SMS). VCS is a reflection seismic method that uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by various acoustic sources. This method is useful to delineate detailed structures in a spatially-limited area below the seabed in the deep sea where conventional surface seismic is not effective. We have been developing an autonomous VCS system with the financial support of the Japanese government since 2009. We have carried out several VCS surveys and completed our VCS system. Izena Cauldron, Okinawa Trough is one of the most promising SMS areas around Japan. There are two high potential areas, the north and south mound. We carried out the first VCS survey around the north mound in 2011 and the second survey around the south mound in 2013 respectively. The first VCS survey in Izena Cauldron was carried out using a GI gun in September, 2011, with the objective of surveying the large-scale and deeper structure of the hydrothermal system. The water depth was 1,500-1,600m. Four VCS systems were deployed. The shooting lines covered an area of 9 km x 9 km with a shooting interval of about 25m and line spacing of 200m to 400m. In the second survey, we used a high-voltage sparker. The objective is to explore very shallow parts to delineate very thin SMS deposits. The survey area was about 4 km x 4km with a 12.5 m shooting interval and 100m to 200m line spacing. Three VCS systems were deployed in this survey. The result of the first GI gun VCS survey was a 3D PSDM volume of the subsurface structure. It extends 2,000m horizontally and down to 1,500m in depth. Further, by re-processing the data with a

  6. Spatial and temporal distribution of pore gas concentrations during mainstream large-scale trough composting in China.

    Science.gov (United States)

    Zeng, Jianfei; Shen, Xiuli; Sun, Xiaoxi; Liu, Ning; Han, Lujia; Huang, Guangqun

    2018-02-02

    With the advantages of high treatment capacity and low operational cost, large-scale trough composting has become one of the mainstream composting patterns in composting plants in China. This study measured concentrations of O 2 , CO 2 , CH 4 and NH 3 on-site to investigate the spatial and temporal distribution of pore gas concentrations during mainstream large-scale trough composting in China. The results showed that the temperature in the center of the pile was obviously higher than that in the side of the pile. Pore O 2 concentration rapidly decreased and maintained distribution and promote the composting process during large-scale trough composting when the pile was naturally aerated, which will contribute to improving the current undesirable atmosphere environment in China. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Evaluation of the variability and safety of serum trough concentrations of vancomycin in patients admitted to the intensive care unit.

    Science.gov (United States)

    Qian, Xiaodan; Du, Guantao; Weng, Chunmei; Zhou, Haijun; Zhou, Xianju

    2017-07-01

    To examine the variability and safety of serum trough concentrations of vancomycin in patients admitted to the intensive care unit (ICU) and to analyze the factors influencing the trough concentration. Data were collected retrospectively from ICU patients receiving vancomycin treatment at a fixed dose of 2g/day due to unobtainable weight data, at Changzhou No. 2 People's Hospital, between 2012 and 2015. Vancomycin trough concentrations were compared between groups stratified by sex, age, and estimated glomerular filtration rate (eGFR). The vancomycin trough concentration varied significantly among ICU patients on a fixed dose of 2g/day. Only 16.9% of ICU patients met the concentration target of 15-20mg/l, while 25% of patients showed supratherapeutic concentrations. A higher proportion of female patients than male patients showed supratherapeutic concentrations (40.4% vs. 15.5%). The trough concentration was positively correlated with age (y=0.279x-2.085; R 2 =0.186) and negatively correlated with eGFR (y=-0.2x+33.776; R 2 =0.366). Vancomycin-related nephrotoxicity occurred at an incidence of 5.9%. These results suggest that the fixed-dose regimen is not appropriate for ICU patients in view of the low incidence of target trough concentrations and the high incidence of supratherapeutic concentrations. The dose should be individualized based on weight, age, and renal function to improve outcomes and patient safety. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. A study to explore the correlation of ABCB1, ABCG2, OCT1 genetic polymorphisms and trough level concentration with imatinib mesylate-induced thrombocytopenia in chronic myeloid leukemia patients.

    Science.gov (United States)

    Francis, Jose; Dubashi, Biswajit; Sundaram, Rajan; Pradhan, Suresh Chandra; Chandrasekaran, Adithan

    2015-12-01

    Imatinib mesylate is presently the first-line treatment for chronic myeloid leukemia (CML). Therapeutic drug monitoring (TDM) and pharmacogenetic screening is warranted for better management of imatinib therapy. The present study was framed to explore the influence of common drug transporter gene polymorphisms of ABCB1, ABCG2, OCT1 and trough level concentration on commonly occurring adverse events in CML patients treated with imatinib mesylate. A total number of 111 patients in chronic phase (Philadelphia chromosome +ve) were included in the study. The plasma drug concentration of imatinib was estimated using LC-MS/MS method. The mean ± SD trough level concentration of imatinib mesylate was found to be 1430.7 ± 438.7 ng/ml. The trough level concentration at steady state (Cmin.ss) was significantly higher in patients with grade 2-4 thrombocytopenia compared with patients without the adverse event (P value 0.033). The drug level of imatinib in plasma correlates with the severity of thrombocytopenia, which adds to the utility of TDM in the management of CML patients.

  9. Chemical composition of hydrothermal ores from Mid-Okinawa trough and Suiyo Seamount determined by neutron activation analysis

    International Nuclear Information System (INIS)

    Noguchi, Takuroh; Taira, Naoto; Oomori, Tamotsu; Taira, Hatsuo; Tanahara, Akira; Takada, Jitsuya

    2007-01-01

    Neutron activation analysis of 13 hydrothermal ore samples (70 subsamples) collected from the Mid-Okinawa Trough and Suiyo Seamount revealed higher contents of precious metal such as Au and Ag, and those of As, Sb, Ga, and Hg than those from mid-ocean ridge hydrothermal systems. In addition, the Mid-Okinawa Trough samples were richer in Ag and Sb than those from the Suiyo Seamount. The geochemical differences among these hydrothermal ore deposits are regarded as reflecting both differences in the chemical composition of the hosted magma of hydrothermal system and the abundance of sediments that is reacted with hydrothermal fluids. (author)

  10. Waveform anomaly caused by strong attenuation in the crust and upper mantle in the Okinawa Trough region

    Science.gov (United States)

    Padhy, S.; Furumura, T.; Maeda, T.

    2017-12-01

    The Okinawa Trough is a young continental back-arc basin located behind the Ryukyu subduction zone in southwestern Japan, where the Philippine Sea Plate dives beneath the trough, resulting in localized mantle upwelling and crustal thinning of the overriding Eurasian Plate. The attenuation structure of the plates and surrounding mantle in this region associated with such complex tectonic environment are poorly documented. Here we present seismological evidence for these features based on the high-resolution waveform analyses and 3D finite difference method (FDM) simulation. We analyzed regional broadband waveforms recorded by F-net (NIED) of in-slab events (M>4, H>100 km). Using band-passed (0.5-8 Hz), mean-squared envelopes, we parameterized coda-decay in terms of rise-time (time from P-arrival to maximum amplitude in P-coda), decay-time (time from maximum amplitude to theoretical S-arrival), and energy-ratio defined as the ratio of energy in P-coda to that in direct P wave. The following key features are observed. First, there is a striking difference in S-excitation along paths traversing and not traversing the trough: events from SW Japan not crossing the trough show clear S waves, while those occurring in the trough show very weak S waves at a station close to the volcanic front. Second, some trough events exhibit spindle-shaped seismograms with strong P-coda excitation, obscuring the development of S waves, at back-arc stations; these waveforms are characterized by high decay-time (>10s) and high energy-ratio (>>1.0), suggesting strong forward scattering along ray paths. Third, some trough events show weak S-excitation characterized by low decay-time (<5s) and low energy-ratio (<1.0) at fore-arc stations, suggesting high intrinsic absorption. To investigate the mechanism of the observed anomalies, we will conduct FDM simulation for a suite of models comprising the key subduction features like localized mantle-upwelling and crustal thinning expected in the

  11. Sedimentary response to tectonism in the extensional Chihuahua trough, Cretaceous of Southern North America

    Science.gov (United States)

    Budhathoki, P.; Langford, R. P.; Pavlis, T. L.

    2009-12-01

    During the Jurassic and Cretaceous, the Chihuahua Trough formed an extensional basin, extending from the Gulf of Mexico to Southern Arizona, along the Present Border of the United States and Mexico. West of the Big Bend of Texas, Jurassic and Cretaceous sediments are less than 150 m thick, and in many areas are absent. The sedimentary package thickens to over 3km within the trough. The Albian Cox Sandstone is one of the most areally extensive formations and consists of interbedded fluvial coastal and shallow marine sandstones and shales. In this study area, shales (10-70 m) are thicker more than sandstone beds (2-10 m). This unit is overlain by Finlay formation, a fine crystalline gray limestone and underlain by Bluff Mesa formation, a fossiliferous shallow marine limestone. Cross-bedded, brown, fine to medium grained sandstone, interbedded with siltstone, shale and limestone are characteristic lithology of the Cox. The Indio Mountains of Trans-Pecos Texas offer an ideal location to study how this package accommodates the deformation associated with the subsiding Chihuahua trough. A continuous outcrop extends over 30 km oblique to the basin margin and thickens from approximately 375 m on the northern side to 437 m on the southern side of the 10 km section studied so far. One important mechanism is rotation of the strata into the basin, followed by truncation along sequence boundaries. The lower two sequence in the southern Indio mountains are rotated down to the basin relative to Finlay. The lowest sequences thicken from an erosional pinch out towards the South. Shale beds thicken within the rotated strata and accommodate some of the tilting. For example, Thickness of the shale bed varies from 18 m to 70 m within a 2 km distance. However, erosional truncation of the tilted strata accounts for most of the increases in thickness within sequences. The base of the formation has been rotated about 6 degrees south relative to the top of the formation. Another observed

  12. Three-dimensional distribution of random velocity inhomogeneities at the Nankai trough seismogenic zone

    Science.gov (United States)

    Takahashi, T.; Obana, K.; Yamamoto, Y.; Nakanishi, A.; Kaiho, Y.; Kodaira, S.; Kaneda, Y.

    2012-12-01

    The Nankai trough in southwestern Japan is a convergent margin where the Philippine sea plate is subducted beneath the Eurasian plate. There are major faults segments of huge earthquakes that are called Tokai, Tonankai and Nankai earthquakes. According to the earthquake occurrence history over the past hundreds years, we must expect various rupture patters such as simultaneous or nearly continuous ruptures of plural fault segments. Japan Agency for Marine-Earth Science and Technology (JAMSTEC) conducted seismic surveys at Nankai trough in order to clarify mutual relations between seismic structures and fault segments, as a part of "Research concerning Interaction Between the Tokai, Tonankai and Nankai Earthquakes" funded by Ministry of Education, Culture, Sports, Science and Technology, Japan. This study evaluated the spatial distribution of random velocity inhomogeneities from Hyuga-nada to Kii-channel by using velocity seismograms of small and moderate sized earthquakes. Random velocity inhomogeneities are estimated by the peak delay time analysis of S-wave envelopes (e.g., Takahashi et al. 2009). Peak delay time is defined as the time lag from the S-wave onset to its maximal amplitude arrival. This quantity mainly reflects the accumulated multiple forward scattering effect due to random inhomogeneities, and is quite insensitive to the inelastic attenuation. Peak delay times are measured from the rms envelopes of horizontal components at 4-8Hz, 8-16Hz and 16-32Hz. This study used the velocity seismograms that are recorded by 495 ocean bottom seismographs and 378 onshore seismic stations. Onshore stations are composed of the F-net and Hi-net stations that are maintained by National Research Institute for Earth Science and Disaster Prevention (NIED) of Japan. It is assumed that the random inhomogeneities are represented by the von Karman type PSDF. Preliminary result of inversion analysis shows that spectral gradient of PSDF (i.e., scale dependence of

  13. Single-dose tenofovir and emtricitabine for reduction of viral resistance to non-nucleoside reverse transcriptase inhibitor drugs in women given intrapartum nevirapine for perinatal HIV prevention: an open-label randomised trial.

    Science.gov (United States)

    Chi, Benjamin H; Sinkala, Moses; Mbewe, Felistas; Cantrell, Ronald A; Kruse, Gina; Chintu, Namwinga; Aldrovandi, Grace M; Stringer, Elizabeth M; Kankasa, Chipepo; Safrit, Jeffrey T; Stringer, Jeffrey S A

    2007-11-17

    Intrapartum and neonatal single-dose nevirapine are essential components of perinatal HIV prevention in resource-constrained settings, but can induce resistance to other non-nucleoside reverse transcriptase inhibitor drugs. We aimed to investigate whether this complication would be reduced with a single peripartum intervention of tenofovir and emtricitabine. We randomly assigned 400 HIV-infected pregnant women who sought care at two public-sector primary health facilities in Lusaka, Zambia. One was excluded, 200 were assigned to receive a single oral dose of 300 mg tenofovir disoproxil fumarate with 200 mg emtricitabine under direct observation, and 199 to receive no study drug. Short-course zidovudine and intrapartum nevirapine were offered to all HIV-infected women, according to the local standard of care. Women who met national criteria for antiretroviral therapy were referred for care and not enrolled. Our primary study outcome was resistance to non-nucleoside reverse transcriptase inhibitors at 6 weeks after delivery. We used standard population sequencing to determine HIV genotypes. Analysis was per protocol. This study is registered with ClinicalTrials.gov, number NCT00204308. Of the 200 women who were randomly assigned to the intervention, 14 were lost to follow-up or withdrew from the study, two did not take study drug according to protocol, and one specimen was lost; 23 of 199 controls were lost to follow-up or withdrew from the study, and three specimens were lost. Women given the intervention were 53% less likely than controls to have a mutation that conferred resistance to non-nucleoside reverse transcriptase inhibitors at 6 weeks after delivery (20/173 [12%] vs 41/166 [25%]; risk ratio [RR] 0.47, 95% CI 0.29-0.76). We noted postpartum anaemia, the most common serious adverse event in mothers, in four women in each group. 20 of 198 (10%) infants in the intervention group and 23 of 199 (12%) controls had a serious adverse event, mostly due to

  14. Influence of the monsoon trough on air-sea interaction in the head of the Bay of Bengal during the southwest monsoon of 1990 (monsoon trough boundary layer experiment - 90)

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, Y.V.B.; Seetaramayya, P.; Murty, V.S.N.; Rao, D.P.

    (-1) respectively. During the depression period the heat loss across the air-sea interface matched well with the heat loss in the upper (approx equal to 100 m) ocean. With the northward movement of the monsoon trough, the momentum and surface heat...

  15. Recent Observational Results of Seafloor Crustal Deformation Along the Suruga-Nankai Trough, Japan

    Science.gov (United States)

    Tadokoro, K.; Sugimoto, S.; Watanabe, T.; Muto, D.; Kimoto, A.; Okuda, T.; Ikuta, R.; Sayanagi, K.; Kuno, M.

    2008-12-01

    The Suruga-Nankai Trough is one of the active plate boundaries in the world. The Philippine Sea plate is subducting beneath the Amurian (Eurasian) plate along the tough, and major subduction earthquakes, Nankai and Tonankai earthquakes, have repeatedly occurred with intervals of about 100-150 years. The 1944 Tonankai and 1946 Nankai earthquakes are the most recent significant earthquakes along the trough. Therefore, the 50-years probabilities of the next major earthquakes are estimated at 80-90% by Headquarters for Earthquake Research Promotion, Japanese Government. It is, therefore, necessary to start monitoring crustal deformation above the source regions of the major earthquakes where in the ocean area. We developed a new system composed of the precise acoustic ranging and kinematic GPS positioning techniques for monitoring of seafloor crustal deformation [Tadokoro et al., 2006, GRL; Ikuta et al., 2008, JGR]. We had installed seven seafloor benchmarks for acoustic ranging at the Suruga-Nankai Trough region between 2002 and 2004. The water depths at the benchmarks are about 800 to 2000 m. We installed a new seafloor benchmark at the eastern margin of the Kumano Basin on June 23, 2008. Three seafloor benchmarks had been aligned perpendicular to the trough axis. In contrast, the new benchmark was installed eastward relative to the pre-installed benchmarks, and we can monitor lateral variations in crustal deformation at the region. We started the repeated measurements at four benchmarkes (two at the Kumano Basin named KMN and KMS, and the other two at the Suruga Bay named SNW and SNE) in 2005. The number of times we have measured are seven, eleven, three and nine times at KMN, KMS, SNW and SNE, respectively. Recent results of the repeated measurements show the following horizontal velocities with relative to the Amurian Plate: 6.4 cm/yr, N86W at KMN; 5.3 cm/yr, N71W at KMS; 3.3 cm/yr, N57W at SNE. The errors of the horizontal velocities are 1-3 cm/yr. Unfortunately

  16. Study of a new solar adsorption refrigerator powered by a parabolic trough collector

    Energy Technology Data Exchange (ETDEWEB)

    El Fadar, A. [Energetic Laboratory, Sciences Faculty, BP 2121, 93000 Tetouan, Abdelmalek Essaadi University (Morocco); Mimet, A. [Energetic Laboratory, Sciences Faculty, BP 2121, 93000 Tetouan, Abdelmalek Essaadi University (Morocco)], E-mail: mimet@fst.ac.ma; Azzabakh, A. [Energetic Laboratory, Sciences Faculty, BP 2121, 93000 Tetouan, Abdelmalek Essaadi University (Morocco); Perez-Garcia, M. [Dpto. de Fisica Aplicada - Universidad de Almeria (Spain); Castaing, J. [Laboratoire Thermique, Energetique et Procedes (LaTEP), Avenue de l' Universite, BP 1155, 64013 Pau Cedex (France)

    2009-04-15

    This paper presents the study of solar adsorption cooling machine, where the reactor is heated by a parabolic trough collector (PTC) and is coupled with a heat pipe (HP). This reactor contains a porous medium constituted of activated carbon, reacting by adsorption with ammonia. We have developed a model, based on the equilibrium equations of the refrigerant, adsorption isotherms, heat and mass transfer within the adsorbent bed and energy balance in the hybrid system components. From real climatic data, the model computes the performances of the machine. In comparison with other systems powered by flat plate or evacuated tube collectors, the predicted results, have illustrated the ability of the proposed system to achieve a high performance due to high efficiency of PTC, and high flux density of heat pipe.

  17. Design and modeling of solar parabolic trough power plant with MATLAB

    Directory of Open Access Journals (Sweden)

    Mohammad Sanan T.

    2017-01-01

    Full Text Available With the fact that Malaysia is one of the fast- growing countries, demand of energy increment is rapid. Malaysia is able to obtain ample amount of annual solar radiation due to its location at equator. If this is utilized proficiently and effectively, then, it can suffice the domestic needs as well as the industrial needs in terms of energy consumption. This article proposes a parabolic Trough Power Plant which is designed with 1.2 kW net electric output. Consequently, the results of theoretical calculations are detailed in the article, while, ensuring the analysing of design proposed through the MATLAB software. The results showed that by making use of aperture having an area of approximately 80 m2, maximum useful heat gain of 20701W at 13:00 pm was attained in March. The maximum net power is 11.84 kWh/day in February.

  18. Design and Implementation of PLC-Based Automatic Sun tracking System for Parabolic Trough Solar Concentrator

    Directory of Open Access Journals (Sweden)

    Wang Jinping

    2016-01-01

    Full Text Available A sun-tracking system for parabolic trough solar concentrators (PTCs is a control system used to orient the concentrator toward the sun always, so that the maximum energy can be collected. The work presented here is a design and development of PLC based sun tracking control system for PTC. Sun tracking control system consists of a Programmable Logic Controller (PLC and a single axis hydraulic drives tracking control system. Hydraulic drives and the necessary tracking angle algorithm have been designed and developed to perform the technical tasks. A PLC unit was employed to control and monitor the mechanical movement of the PTC and to collect and store data related to the tracking angle of PTC. It is found that the tracking error of the system is less than 0.6°. Field experience shows that tracking algorithm act stable and reliable and suit for PTCs.

  19. Potential for using parabolic trough collectors to supplement power cycle boilers

    Science.gov (United States)

    Schimmel, W. P., Jr.; Lukens, L. L.

    1981-11-01

    The advantage of such a system is that solar energy is used to heat the water in a steam Rankine cycle device up to the superheat regime, thus displacing the fossil fuel usually required. The temperature associated with this portion of the power cycle is typically on the order of 320 C or less, which makes it compatible with current parabolic trough collector systems. A system model which lends itself to optimization studies was constructed and exercised over a range of the multiparameter space involved. The collector field, storage, supplementary fossil boiler and superheater, and turbine/generator traded off to obtain a series of economically optimal systems for various years and solar fractions.

  20. Strain Accumulation Estimated from Seafloor Crustal Deformation at the Nankai Trough, Japan

    Science.gov (United States)

    Tadokoro, K.; Watanabe, T.; Nagai, S.; Ikuta, R.; Okuda, T.; Kenji, Y.; Sakata, T.

    2012-12-01

    Our research has developed an observation system for seafloor crustal deformation composed of the kinematic GPS and acoustic ranging techniques [Tadokoro et al., 2006; Ikuta et al., 2008]. We monitored crustal deformation at the Nankai Trough, Japan, where the Philippine Sea Plate subducts beneath the Amurian Plate. The convergence rate is predicted at 60 mm/y in the N59W direction by the Euler vector of REVEL [Sella et al., 2002]. We installed three monitoring sites (named KMN, KMS, and KME) on the seafloor at depths of about 1920-2030 m. The sites KMN and KMS are installed perpendicular to the trough axis with a spacing of 20 km; the site KME is 50 km from KMN and KMS in the direction parallel to the trough axis. The monitoring was started in 2004, 2005, and 2008 at KMS, KMN, and KME, respectively. The numbers of measurements are 16, 20, and 5 times at KMN, KMS, and KME, respectively. We obtained 3-7 years averaged horizontal site velocities within ITRF2000 adopting a robust estimation method with Tukey's biweight function to the time series of site position measured until the end of 2011. Substituting the synthetic rigid block motions of the Amurian Plate from the velocities within ITRF2000, we obtained the following site velocities with respect to the Amurian Plate [Tadokoro et al., 2012]: KMN 41±4 mm/y, N77±7W KMS 43±5 mm/y, N80±6W KME 42±5 mm/y, N80±7W In contrast, the on-land GPS horizontal velocities along the coast is 23-33 mm/y toward N74-80W. The present observational results show: (1) the velocity vectors are all the same length and direction, which indicates no internal deformation in this region; (2) the back-slip model predicts that the plate interface beneath the region is uniformly locked with coupling ratios of 60-80 %, indicating strain accumulation that will be released during the anticipated mega-thrust Tonankai earthquake; and (3) the directions of site velocities differ from that of convergence vector by 20 degrees, which is affected by

  1. Fat transposition with a single subdermal stitch for the treatment of deep tear trough.

    Science.gov (United States)

    Medel, Ramón; Hristodulopulos, Vanessa; Vásquez, LuzMaría

    2014-12-01

    To describe a fixation technique of the medial and central fat pads in the subperiosteal pocket for transconjunctival fat transposition, using a single subdermal, non-removable, non-absorbable stitch. Retrospective study of 19 patients with bilateral deep tear through treated by means of transconjunctival fat transposition. Charts and photographic records were reviewed. Photographical and clinical improvement of the deep tear through and fat prolapse was observed in all patients in variable degrees. There were no intraoperative complications. Significant periocular hematoma occurred in 1 patient and solved without complications. Two patients presented transitory fat pedicle hardening and one patient presented a conjunctival inferior fornix granuloma, surgically removed. All patients were satisfied. Transconjunctival subperiosteal fat transposition with single subdermal stitch to fix the medial and central fat pads, for the treatment of deep tear trough and fat prolapse demonstrated high patient satisfaction, good aesthetic results with no significant or permanent complications.

  2. Optical testing of a parabolic trough solar collector by a null screen with stitching

    Science.gov (United States)

    Moreno-Oliva, V., I.; Campos-Garcia, M.; Granados-Agustin, F.; Arjona-Pérez, M. J.; Díaz-Uribe, R.; Avendaño-Alejo, M.

    2009-06-01

    In this work we report a method for testing a parabolic trough solar collector (PTSC) based on the null screen principles. For surfaces with symmetry of revolution a cylindrical null screen is used, now, for testing the PTSC we use a flat null screen. The design of the null screen with ellipsoidal spots is described; its image, which is formed by reflection on the test surface, becomes an exact square array of circular spots if the surface is perfect. Any departure from this geometry is indicative of defects on the surface. The flat null screen design and the surface evaluation algorithm are presented. Here the surface is tested in sections and the evaluation of the shape of the surface is performed with stitching method. Results of the evaluation for a square PTSC with 1000 mm by side (F/0.49) are shown.

  3. Analisa Efisiensi Prototype Solar Collector Jenis Parabolic Trough dengan Menggunakan Cover Glass Tube pada Pipa Absorber

    Directory of Open Access Journals (Sweden)

    Hartamas Ridho Prasetyo

    2015-06-01

    Full Text Available Energi tidak dapat diciptakan maupun dimusnahkan, hanya dapat dikonversikan dari satu bentuk ke bentuk lainnya (Hukum Kekekalan Energi. Energi sangat penting dalam kehidupan sehari – hari khususnya energi listrik yang kebutuhan terhadap energi ini sangat besar sedangkan sebagian besar energi listrik dihasilkan dari sumber daya fosil yang mulai menipis jumlahnya. Ketergantungan akan minyak bumi untuk jangka panjang tidak dapat di pertahankan lebih lama jika pemakaian melebihi batas wajar. Dalam Tugas Akhir ini penulis melakukan analisa alat Parabolic Trough Solar Collector dengan memanfaatkan energi radiasi matahari, yang di awali adanya perancangan desain alat PTSC dengan material yang sudah di tentukan sebelumnya. Prototype tersebut hanya bisa dilakukan pengujian dengan posisi steady state atau diam antara jam 11.30 sampai dengan 12.30 siang. Dengan adanya penelitian tentang analisa performa pada alat tersebut, telah di dapatkan beberapa hasil nilai variabel yang signifikan dan berpengaruh besar dengan nilai performa alat tersebut.

  4. Analysis of defects on the slopes on a parabolic trough solar collector with null-screens

    Science.gov (United States)

    Campos-García, Manuel; Huerta-Carranza, Oliver; Díaz-Uribe, Rufino; Moreno-Oliva, Víctor I.

    2015-09-01

    The null-screen method has been used to test aspheric surfaces, among them the surface of a parabolic trough solar collector (PTSC). This geometrical method measures the slope of the test surface and by a numerical integration procedure the shape of the test surface can be obtained. In this work, through some numerical simulations sinusoidal deformations with different amplitudes and spatial periods are introduced on PTSC surfaces. Then, an analysis of the deformations of the reflected images of a null-screen by the PTSC surface due to defects on the surface is performed. This procedure allows to validate the kind and magnitude of the surface deformations that can be measured with the proposed method. Also, an analysis of the advantages and limitations of the null-screen testing method will be discussed.

  5. Heat Flow in the Salton Trough Revisited and Implications for Regional Tectonics

    Science.gov (United States)

    Williams, C.; DeAngelo, J.; Galanis, P.

    2012-12-01

    As part of research into the geothermal energy resources of the Salton Trough, we have assembled a database of 1060 temperature-gradient and heat-flow measurements acquired by the geothermal industry, universities, national labs, and the US Geological Survey (USGS) throughout the region from the early 1970s to the present. In addition to using the data to examine the nature and occurrence of hydrothermal systems, we have estimated the total heat flux through the Trough and investigated relationships between subsurface thermal conditions and the character of faulting and seismicity. Our analysis for the Imperial Valley and other portions of the Salton Trough physiographic province gives an average heat flow of ~160 mW/m2 compared to the 140 mW/m2 average determined by Lachenbruch and others in the last regional study (JGR, v.90, n. B8, 1986). The higher average reflects a larger contribution to the total heat flux from hydrothermal systems that was not recognized in earlier studies due to incomplete spatial coverage. Most of these hydrothermal systems are associated with step-overs and other structural complexities in the fault zones that pass through the region, and the dense coverage of the new heat flow database allows for a detailed examination of the degree to which variations of convective and conductive heat transfer in this region influence, and are influenced by, active tectonic processes. We compared estimated subsurface temperatures from a conductive heat transfer model with the observed depth variation of the upper and lower boundaries of the seismogenic zone along active faults both within and along the margins of the Imperial Valley, and for those areas characterized by average heat flow less than or equal to 150 mW/m2, the base of the seismogenic zone is near the estimated depth of the 400 °C isotherm, a result that is consistent with observations in other seismically active regions. The base of seismicity continues to shallow where heat flow

  6. Evidence for chaotic fault interactions in the seismicity of the San Andreas fault and Nankai trough

    Science.gov (United States)

    Huang, Jie; Turcotte, D. L.

    1990-01-01

    The dynamical behavior introduced by fault interactions is examined here using a simple spring-loaded, slider-block model with velocity-weakening friction. The model consists of two slider blocks coupled to each other and to a constant-velocity driver by elastic springs. For an asymmetric system in which the frictional forces on the two blocks are not equal, the solutions exhibit chaotic behavior. The system's behavior over a range of parameter values seems to be generally analogous to that of weakly coupled segments of an active fault. Similarities between the model simulations and observed patterns of seismicity on the south central San Andreas fault in California and in the Nankai trough along the coast of southwestern Japan.

  7. Inflow of Atlantic-origin waters to the Barents Sea along glacial troughs

    Directory of Open Access Journals (Sweden)

    Gennady G. Matishov

    2009-09-01

    Full Text Available This paper discusses the role of glacial shelf topography in the formation of general oceanological and biological mechanisms in the Barents Sea. Analysis of geomorphological data and oceanographic observations obtained on board MMBI research vessels in 2001-08 has shown that: fluxes of Atlantic-origin waters pass along glacial troughs; the inflow of Atlantic waters to the Barents Sea from the west increased from 2001 till 2007, although this advection began to weaken in 2008; vertical and horizontal thermohaline gradients intensified during the investigated period; a warm period similar to that of the 1930s was observed in the Barents Sea at the beginning of the 21st century.

  8. Relationship between serum trough infliximab levels, pretreatment C reactive protein levels, and clinical response to infliximab treatment in patients with rheumatoid arthritis

    NARCIS (Netherlands)

    Wolbink, G. J.; Voskuyl, A. E.; Lems, W. F.; de Groot, E.; Nurmohamed, M. T.; Tak, P. P.; Dijkmans, B. A. C.; Aarden, L.

    2005-01-01

    Objective: To investigate the relationship between serum trough infliximab levels and clinical response to infliximab treatment in patients with rheumatoid arthritis (RA). Methods: Disease activity and serum trough infliximab levels before and 2, 6, and 14 weeks after initiation of infliximab

  9. Theoretical investigation of solar humidification-dehumidification desalination system using parabolic trough concentrators

    International Nuclear Information System (INIS)

    Mohamed, A.M.I.; El-Minshawy, N.A.

    2011-01-01

    Highlights: → We evaluated the performance of sea water HDD system powered by solar PTC. → The proposed design to the expected desalination plant performance was introduced. → The collector thermal efficiency was a function of solar radiation value. → The highest fresh water productivity is found to be in the summer season. → The production time reaches 42% of the day time in the summer season. - Abstract: This paper deals with the status of solar energy as a clean and renewable energy applications in desalination. The object of this research is to theoretically investigate the principal operating parameters of a proposed desalination system based on air humidification-dehumidification principles. A parabolic trough solar collector is adapted to drive and optimize the considered desalination system. A test set-up of the desalination system was designed and a theoretical simulation model was constructed to evaluate the performance and productivity of the proposed solar humidification-dehumidification desalination system. The theoretical simulation model was developed in which the thermodynamic models of each component of the considered were set up respectively. The study showed that, parabolic trough solar collector is the suitable to drive the proposed desalination system. A comparison study had been presented to show the effect of the different parameters on the performance and the productivity of the system. The productivity of the proposed system showed also an increase with the increase of the day time till an optimum value and then decreased. The highest fresh water productivity is found to be in the summer season, when high direct solar radiation and long solar time are always expected. The production time reaches a maximum value in the summer season, which is 42% of the day.

  10. Performance Analysis and Optimization of a Parabolic Trough Solar Power Plant in the Middle East Region

    Directory of Open Access Journals (Sweden)

    Praveen R. P.

    2018-03-01

    Full Text Available The Middle East is one among the areas of the world that receive high amounts of direct solar radiation. As such, the region holds a promising potential to leverage clean energy. Owing to rapid urbanization, energy demands in the region are on the rise. Along with the global push to curb undesirable outcomes such as air pollution, emissions of greenhouse gases, and climate change, an urgent need has arisen to explore and exploit the abundant renewable energy sources. This paper presents the design, performance analysis and optimization of a 100 MWe parabolic trough collector Solar Power Plant with thermal energy storage intended for use in the Middle Eastern regions. Two representative sites in the Middle East which offer an annual average direct normal irradiance (DNI of more than 5.5 kWh/m2/day has been chosen for the analysis. The thermodynamic aspect and annual performance of the proposed plant design is also analyzed using the System Advisor Model (SAM version 2017.9.5. Based on the analysis carried out on the initial design, annual power generated from the proposed concentrating solar power (CSP plant design in Abu Dhabi amounts to 333.15 GWh whereas that in Aswan recorded a value of 369.26 GWh, with capacity factors of 38.1% and 42.19% respectively. The mean efficiency of the plants in Abu Dhabi and Aswan are found to be 14.35% and 14.98% respectively. The optimization of the initial plant design is also carried out by varying two main design parameters, namely the solar multiple and full load hours of thermal energy storage (TES. Based on the findings of the study, the proposed 100 MW parabolic trough collector solar power plant with thermal energy storage can contribute to the sustainable energy future of the Middle East with reduced dependency on fossil fuels.

  11. Interaction between Antarctic sea ice and synoptic activity in the circumpolar trough

    Science.gov (United States)

    Schlosser, Elisabeth

    2010-05-01

    Different from conditions in the Arctic, total Antarctic sea ice extent does not show large interannual variability and almost no long-term trend is found. On a regional/monthly scale, however, large differences are observed, depending on winds and oceanic currents, thus on the prevailing synoptic weather situation. At the same time, the sea ice influences atmospheric conditions: presence of sea ice considerably changes the energy exchange between ocean and atmosphere, thus the meridional air temperature gradient, which is usually strongest at the sea ice edge. This leads to high baroclinicity in this area and thus favours cyclogenesis. The position and movement of low pressure systems, in turn, together with the local heat balance, determines sea ice extent and concentration. Divergence and convergence of sea ice also depends on the position of the circumpolar trough relative to the sea ice edge, since its position determines whether the atmospheric flow is predominantly easterly or westerly, which leads to sea ice transport to the southwest or the northeast, respectively. The circumpolar trough is usually situated closer to the coast in spring and autumn and moves north in summer and winter. In this study, meteorological data from the ECMWF ERA-interim reanalysis as well as sea ice extent and concentration derived from passive microwave data (SSMI/SMMR) are used to investigate the interactions between Antarctic sea ice and synoptic activity in the polar ocean. Special consideration is given to the frequency of regional sea ice minima and warm air advection from lower latitudes. A stable synoptic situation with amplified Rossby waves can lead to regional extrema in sea ice extent. An extreme case was observed in the austral summer of 2001/2002 in the Weddell Sea, when continuous northwesterly winds removed the ice from the northwestern part of the Weddell Sea and drove it to the coast of Coats Land, where usually coastal polynyas are observed in summer.

  12. The experimental study of a two-stage photovoltaic thermal system based on solar trough concentration

    International Nuclear Information System (INIS)

    Tan, Lijun; Ji, Xu; Li, Ming; Leng, Congbin; Luo, Xi; Li, Haili

    2014-01-01

    Highlights: • A two-stage photovoltaic thermal system based on solar trough concentration. • Maximum cell efficiency of 5.21% with the mirror opening width of 57 cm. • With single cycle, maximum temperatures rise in the heating stage is 12.06 °C. • With 30 min multiple cycles, working medium temperature 62.8 °C, increased 28.7 °C. - Abstract: A two-stage photovoltaic thermal system based on solar trough concentration is proposed, in which the metal cavity heating stage is added on the basis of the PV/T stage, and thermal energy with higher temperature is output while electric energy is output. With the 1.8 m 2 mirror PV/T system, the characteristic parameters of the space solar cell under non-concentrating solar radiation and concentrating solar radiation are respectively tested experimentally, and the solar cell output characteristics at different opening widths of concentrating mirror of the PV/T stage under condensation are also tested experimentally. When the mirror opening width was 57 cm, the solar cell efficiency reached maximum value of 5.21%. The experimental platform of the two-stage photovoltaic thermal system was established, with a 1.8 m 2 mirror PV/T stage and a 15 m 2 mirror heating stage, or a 1.8 m 2 mirror PV/T stage and a 30 m 2 mirror heating stage. The results showed that with single cycle, the long metal cavity heating stage would bring lower thermal efficiency, but temperature rise of the working medium is higher, up to 12.06 °C with only single cycle. With 30 min closed multiple cycles, the temperature of the working medium in the water tank was 62.8 °C, with an increase of 28.7 °C, and thermal energy with higher temperature could be output

  13. Evaluation of Infliximab Therapy in Children with Crohn's Disease Using Trough Levels Predictors.

    Science.gov (United States)

    Ohem, Jan; Hradsky, Ondrej; Zarubova, Kristyna; Copova, Ivana; Bukovska, Petra; Prusa, Richard; Malickova, Karin; Bronsky, Jiri

    2018-01-01

    In adults, infliximab (IFX) levels correlate with disease activity, and antibodies to IFX (ATIs) predict treatment failure. We aimed to determine the association of IFX levels and ATIs with disease activity in a paediatric population. We prospectively collected blood, stool, and clinical data from 65 patients (age 10.5-15.1 years) with Crohn's disease (CD) before IFX administration, and measured IFX trough levels, ATIs, and faecal calprotectin levels (CPT). Samples were collected during maintenance therapy. We used multivariate analysis to identify the predictors of IFX levels. Lower levels of IFX were associated with ATIs positivity (OR 0.027, 95% CI 0.009-0.077). Higher C-reactive protein (CRP) level, erythrocyte sedimentation rate, and CPT levels were found in patients with lower IFX levels. The optimal combination of sensitivity (0.5) and specificity (0.74) for disease activity was calculated for IFX levels ≥1.1 µg/mL using CRP level <5 mg/L as a marker of laboratory remission. In a model that used CPT ≤100 µg/g as the definition of remission, the optimal IFX trough level was 3.5 µg/mL. No independent association between remission and ATIs was found in our study population. However, we found an independentz association between IFX levels and serum albumin levels (OR 1.364, 95% CI 1.169-1.593), p < 0.001. Key Messages: The paediatric population was similar to adult populations in terms of the association between IFX and ATIs as well as between IFX and disease activity. © 2017 S. Karger AG, Basel.

  14. Mineral chemistry indicates the petrogenesis of rhyolite from the southwestern Okinawa Trough

    Science.gov (United States)

    Chen, Zuxing; Zeng, Zhigang; Wang, Xiaoyuan; Zhang, Yuxiang; Yin, Xuebo; Chen, Shuai; Ma, Yao; Li, Xiaohui; Qi, Hanyan

    2017-12-01

    To reveal the petrogenesis of rhyolite from the southwestern Okinawa Trough, the mineral chemistry of plagioclase, orthopyroxene, amphibole, quartz and Fe-Ti oxide phenocrysts were analyzed using an electron microprobe, and in suit Sr and Ba contents of plagioclase analysed by LA-ICPMS were chosen for fingerprinting plagioclases of different provenances. Results indicate an overall homogeneous composition for each of the mineral phases except for plagioclase phenocrysts which have a wide range of composition (An=39 88). Plagioclase crystals characterized by An contents of >70 are not in equilibrium with their whole-rock compositions, and coarse-sieved plagioclase phenocryst interiors record high An contents (>70) and Sr/Ba ratios (>7), which are similar to the those of plagioclase crystals in basalt. Therefore, these crystals must have been introduced to the rhyolitic magma from a more mafic source. Equilibrium temperatures estimated using orthopyroxene-liquid, iron-titanium oxide, titanium-in-quartz and amphibole geothermometers show consistent values ranging from 792 to 869°C. The equilibrium pressure calculated using amphibole compositions is close to 121 MPa which corresponds to an approximate depth of 4 km. The fO2 conditions estimated from Fe-Ti oxides and amphiboles plot slightly above the NNO buffer, which indicates that the rock formed under more oxidized conditions. Our results suggests that petrogenesis of the rhyolite due to basaltic magma ascend with the high An and Sr/Ba plaigoclases from deep magma chamber into the shallow chamber where the fractional crystallization and crustal assimilation happened. It also indicates that a two-layer magma chamber structure may occur under the southwestern Okinawa Trough.

  15. Prospective, Observational Study of Voriconazole Therapeutic Drug Monitoring among Lung Transplant Recipients Receiving Prophylaxis: Factors Impacting Levels of and Associations between Serum Troughs, Efficacy, and Toxicity

    Science.gov (United States)

    Mitsani, Dimitra; Shields, Ryan K.; Toyoda, Yoshiya; Kwak, Eun J.; Silveira, Fernanda P.; Pilewski, Joseph M.; Crespo, Maria M.; Bermudez, Christian; Bhama, Jay K.; Clancy, Cornelius J.

    2012-01-01

    Voriconazole prophylaxis is common following lung transplantation, but the value of therapeutic drug monitoring is unknown. A prospective, observational study of lung transplant recipients (n = 93) receiving voriconazole prophylaxis was performed. Serum voriconazole troughs (n = 331) were measured by high-pressure liquid chromatography. The median initial and subsequent troughs were 1.91 and 1.46 μg/ml, respectively. The age of the patient directly correlated with initial troughs (P = 0.005). Patients that were ≥60 years old and cystic fibrosis patients were significantly more likely to have higher and lower initial troughs, respectively. In 95% (88/93) of patients, ≥2 troughs were measured. In 28% (25/88) and 32% (28/88) of these patients, all troughs were ≤1.5 μg/ml or >1.5 μg/ml, respectively. Ten percent (10/93) and 27% (25/93) of the patients developed invasive fungal infection (tracheobronchitis) and fungal colonization, respectively. The median troughs at the times of positive and negative fungal cultures were 0.92 and 1.72 μg/ml (P = 0.07). Invasive fungal infections or colonization were more likely with troughs of ≤1.5 μg/ml (P = 0.01) and among patients with no trough of >1.5 μg/ml (P = 0.007). Other cutoff troughs correlated less strongly with microbiologic outcomes. Troughs correlated directly with aspartate transferase levels (P = 0.003), but not with other liver enzymes. Voriconazole was discontinued due to suspected toxicity in 27% (25/93) of the patients. The troughs did not differ at the times of suspected drug-induced hepatotoxicity, central nervous system (CNS) toxicity, or nausea/vomiting and in the absence of toxicity. Voriconazole prophylaxis was most effective at troughs of >1.5 μg/ml. A cutoff for toxicity was not identified, but troughs of >4 μg/ml were rare. The data support a target range of >1.5 to 4 μg/ml. PMID:22330924

  16. Microbial community in a sediment-hosted CO(2) lake of the southern Okinawa Trough hydrothermal system RID C-8303-2011

    DEFF Research Database (Denmark)

    Inagaki, Fumio; Kuypers, Marcel M. M.; Tsunogai, Urumu

    2006-01-01

    Increasing levels Of CO(2) in the atmosphere are expected to cause climatic change with negative effects on the earth's ecosystems and human society. Consequently, a variety of CO(2) disposal options are discussed, including injection into the deep ocean. Because the dissolution Of CO(2......) in seawater will decrease ambient pH considerably, negative consequences for deep-water ecosystems have been predicted. Hence, ecosystems associated with natural Co(2) reservoirs in the deep sea, and the dynamics of gaseous, liquid, and solid CO(2) in such environments, are of great interest to science...... and society. We report here a biogeochemical and microbiological characterization of a microbial community inhabiting deep-sea sediments overlying a natural CO(2) lake at the Yonaguni Knoll IV hydrothermal field, southern Okinawa Trough. We found high abundances (> 10(9) CM(-3)) of microbial cells in sediment...

  17. On the high heat flow in the Nankai Trough area—a simulation study on a heat rebound process

    Science.gov (United States)

    Nagihara, S.; Kinoshita, H.; Yamano, M.

    1989-04-01

    A concentration of high heat flow (as high as 120-160 mW/m 2) has been observed in the Nankai Trough, off southwest Japan, where the Philippine Sea plate (Shikoku Basin) is subducting beneath the Japanese landmass. We interpret this high heat flow in the subduction zone as being caused by the recovery of conductive heat flow to the theoretically expected value for the young Shikoku Basin lithosphere after cessation of hydrothermal heat exchange through sediment. The thickening sedimentary cover suppresses the rapid heat exchange between basement and sea water, whereas the topmost part of the basement allows a hydrothermal circulation within it to pump up heat from the hot plate to the sediment cover. We propose to call this process "heat rebound". Numerical simulation shows that significant heat flow recovery can occur and is largely influenced by the sedimentation rate. We believe that the high heat flow in the Nankai Trough is one of the heat rebound cases. However, rapid sedimentation in the trough also indicates that heat flow recovery expected by the simulation is not large enough to explain the trough high heat flow by the heat rebound process only.

  18. Detectability of Middle Mesial Root Canal Orifices by Troughing Technique in Mandibular Molars: A Micro-computed Tomographic Study.

    Science.gov (United States)

    Keleş, Ali; Keskin, Cangül

    2017-08-01

    The objective of the present study was to measure the orifice depth of middle mesial canals (MMCs) and evaluate the detectability of orifices using troughing preparation. For this study, 85 mandibular molar teeth with MMCs were selected from the scanned micro-computed tomographic images. The MMCs were categorized, and the distances between the MMC orifices and the cementoenamel junctions (CEJ) were recorded as the depth of the orifice. Data were evaluated with frequency analysis and a chi-square test using SPSS (SPSS Inc, Chicago, IL), and the results indicated a 5% significance level. It was found that 77.41% of the MMC orifices were at the CEJ level, whereas 5.38% and 9.69% of the MMC orifices were detectable within 1-mm and 2-mm depths from the CEJ, respectively. Of the specimens, 7.52% had MMC orifices deeper than 2 mm from the CEJ. Confluent anatomy was the most frequent configuration. No significant relation was detected between the orifice depth and MMC configuration (P > .05). It was concluded that 77.41% of the specimens did not require troughing preparation, the remaining 15.07% would require troughing, and 7.52% could not be accessed even with the troughing preparation. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Optimization of parabolic trough collector design for varying manufacturing tolerances using a closed-form expression for intercept factor

    Energy Technology Data Exchange (ETDEWEB)

    Gueven, H.M. (San Diego State Univ., CA (United States). Dept. of Mechanical Engineering)

    1994-08-01

    In this paper, a closed-form expression for intercept factor is used to carry out the optimization of parabolic trough collector geometry (rim angle and concentration ratio). It is shown that the presented closed-form expression eliminates the need for a detailed ray-trace computer code and facilitates optimization of the collector optical design parameters.

  20. Evaluation of the variability and safety of serum trough concentrations of vancomycin in patients admitted to the intensive care unit

    Directory of Open Access Journals (Sweden)

    Xiaodan Qian

    2017-07-01

    Conclusions: These results suggest that the fixed-dose regimen is not appropriate for ICU patients in view of the low incidence of target trough concentrations and the high incidence of supratherapeutic concentrations. The dose should be individualized based on weight, age, and renal function to improve outcomes and patient safety.

  1. Survey of Thermal Storage for Parabolic Trough Power Plants; Period of Performance: September 13, 1999 - June 12, 2000

    Energy Technology Data Exchange (ETDEWEB)

    Pilkington Solar International GmbH

    2000-09-29

    The purpose of this report is to identify and selectively review previous work done on the evaluation and use of thermal energy storage systems applied to parabolic trough power plants. Appropriate storage concepts and technical options are first discussed, followed by a review of previous work.

  2. Investigating the reasons of variability in Si IV and C IV broad absorption line troughs of quasars

    Science.gov (United States)

    Stathopoulos, Dimitrios; Lyratzi, Evangelia; Danezis, Emmanuel; Antoniou, Antonios; Tzimeas, Dimitrios

    2017-09-01

    In this paper we analyze the C IV and Si IV broad absorption troughs of two BALQSOs (J101056.69+355833.3, J114548.38+393746.6) to the individual components they consist of. By analyzing a BAL trough to its components we have the advantage to study the variations of the individual absorbing systems in the line of sight and not just the variations of the whole absorption trough or the variations of selected portions of BAL troughs exhibiting changes. We find that the velocity shifts and FWHMs (Full Width at Half Maximum) of the individual components do not vary between an interval of six years. All variable components show changes in the optical depths at line centers which are manifested as variations in the EW (Equivalent Width) of the components. In both BALQSOs, over corresponding velocities, Si IV has higher incidence of variability than C IV. From our analysis, evidence is in favour of different covering fractions between C IV and Si IV. Finally, although most of our results favour the crossing cloud scenario as the cause of variability, there is also strong piece of evidence indicating changing ionization as the source of variability. Thus, a mixed situation where both physical mechanisms contribute to BAL variability is the most possible scenario.

  3. Prevention of HIV-1 Transmission Through Breastfeeding: Efficacy and Safety of Maternal Antiretroviral Therapy Versus Infant Nevirapine Prophylaxis for Duration of Breastfeeding in HIV-1-Infected Women With High CD4 Cell Count (IMPAACT PROMISE): A Randomized, Open-Label, Clinical Trial.

    Science.gov (United States)

    Flynn, Patricia M; Taha, Taha E; Cababasay, Mae; Fowler, Mary Glenn; Mofenson, Lynne M; Owor, Maxensia; Fiscus, Susan; Stranix-Chibanda, Lynda; Coutsoudis, Anna; Gnanashanmugam, Devasena; Chakhtoura, Nahida; McCarthy, Katie; Mukuzunga, Cornelius; Makanani, Bonus; Moodley, Dhayendre; Nematadzira, Teacler; Kusakara, Bangini; Patil, Sandesh; Vhembo, Tichaona; Bobat, Raziya; Mmbaga, Blandina T; Masenya, Maysseb; Nyati, Mandisa; Theron, Gerhard; Mulenga, Helen; Butler, Kevin; Shapiro, David E

    2018-04-01

    No randomized trial has directly compared the efficacy of prolonged infant antiretroviral prophylaxis versus maternal antiretroviral therapy (mART) for prevention of mother-to-child transmission throughout the breastfeeding period. Fourteen sites in Sub-Saharan Africa and India. A randomized, open-label strategy trial was conducted in HIV-1-infected women with CD4 counts ≥350 cells/mm (or ≥country-specific ART threshold if higher) and their breastfeeding HIV-1-uninfected newborns. Randomization at 6-14 days postpartum was to mART or infant nevirapine (iNVP) prophylaxis continued until 18 months after delivery or breastfeeding cessation, infant HIV-1 infection, or toxicity, whichever occurred first. The primary efficacy outcome was confirmed infant HIV-1 infection. Efficacy analyses included all randomized mother-infant pairs except those with infant HIV-1 infection at entry. Between June 2011 and October 2014, 2431 mother-infant pairs were enrolled; 97% of women were World Health Organization Clinical Stage I, median screening CD4 count 686 cells/mm. Median infant gestational age/birth weight was 39 weeks/2.9 kilograms. Seven of 1219 (0.57%) and 7 of 1211 (0.58%) analyzed infants in the mART and iNVP arms, respectively, were HIV-infected (hazard ratio 1.0, 96% repeated confidence interval 0.3-3.1); infant HIV-free survival was high (97.1%, mART and 97.7%, iNVP, at 24 months). There were no significant differences between arms in median time to breastfeeding cessation (16 months) or incidence of severe, life-threatening, or fatal adverse events for mothers or infants (14 and 42 per 100 person-years, respectively). Both mART and iNVP prophylaxis strategies were safe and associated with very low breastfeeding HIV-1 transmission and high infant HIV-1-free survival at 24 months.

  4. Ground-Water-Flow Modeling of a Freshwater and Brine-Filled Aquifer in the Onondaga Trough, Onondaga County, New York - A Summary of Findings

    Science.gov (United States)

    Kappel, William M.; Yager, Richard M.

    2008-01-01

    In 2007, the U.S. Geological Survey (USGS) completed a hydrogeologic study that included the development of a groundwater-flow model of the glacial-drift aquifer in the Onondaga Trough near Syracuse, N.Y., which extends from the Valley Heads Moraine near Tully, N.Y., to Onondaga Lake (fig. 1). Glacial sediments within the Onondaga Trough contain freshwater, saline water, and brine, which has historically supported several chemical industries in Syracuse. The ground-water-flow model was developed as a means to assist the members of the Onondaga Lake Partnership (local, State, and Federal governmental agencies) to assess remediation plans for Onondaga Lake and the Onondaga Creek watershed. Prior to this study, in the late 1990s, very little information was known about the physical nature of the valley-fill aquifer or the quality of water within it. Acquisition of this information would help local agencies understand the interactions of fresh and saline water within the aquifer and Onondaga Lake, and would facilitate the design of proposed and ongoing remediation work in and near the lake. The USGS study characterized the geology and geochemistry of the aquifer system, estimated the rate and direction of ground-water movement, and estimated mass loadings of chloride to Onondaga Lake and its tributaries from natural and anthropogenic sources. The study required analysis of existing hydrogeologic data and drilling of new test wells to collect additional hydrogeologic data to supplement this database. A three-dimensional geologic model of the unconsolidated deposits that fill the Onondaga Trough was developed from this information. Water-quality samples were collected, and hydraulic head (water-level) measurements were made in the test wells. The water samples were analyzed for a variety of chemical constituents to determine the composition and age of saline waters within the aquifer. The geologic model, together with the water-quality and hydraulic-head data, supported

  5. Preliminary Magnetostratigraphic Study of the Split Mountain and Lower Imperial Groups, Split Mountain Gorge, Western Salton Trough, CA

    Science.gov (United States)

    Fluette, A. L.; Housen, B. A.; Dorsey, R. J.

    2004-12-01

    We present preliminary results of a magnetostratigraphic study of Miocene-Pliocene sedimentary rocks of the Split Mt. and lower Imperial Groups exposed in Split Mt. Gorge and eastern Fish Creek-Vallecito basin, western Salton Trough. Precise age control for the base of this thick section is needed to improve our understanding of the early history of extension-related subsidence in this region. The geologic setting and stratigraphic framework are known from previous work by Dibblee (1954, 1996), Woodard (1963), Kerr (1982), Winker (1987), Kerr and Kidwell (1991), Winker and Kidwell (1986; 1996), and others. We have analyzed Upper Miocene to lower Pliocene strata exposed in a conformable section in Split Mt. Gorge, including (in order from the base; nomenclature of Winker and Kidwell, 1996): (1) Split Mt. Group: Red Rock Fm alluvial sandstone; Elephant Trees alluvial conglomerate; and lower megabreccia unit; and (2) lower part of Imperial Group, including: Fish Creek Gypsum; proximal to distal turbidites of the Latrania Fm and Wind Caves Mbr of Deguynos Fm; upper megabreccia unit; marine mudstone and rhythmites of the Mud Hills Mbr (Deguynos Fm); and the basal part of the Yuha Mbr (Deguynos Fm). Measured thickness from the base of the Elephant Trees Cgl to the base of the Yuha Mbr is about 1050 m, consistent with previous measurements of Winker (1987). Paleomagnetic samples were collected at approximately 10 m intervals throughout this section. The upper portion of our sampled section overlaps with the lower part of the section sampled for magnetostratigraphic study by Opdyke et al. (1977) and Johnson et al. (1983). They interpreted the base of their section to be about 4.3 Ma, and calculated an average sedimentation rate of approximately 5.5 mm/yr for the lower part of their section. Good-quality preliminary results from 15 paleomagnetic sites distributed throughout our sampled section permit preliminary identification of 6 polarity zones. Based on regional mapping

  6. Interplate locking derived from seafloor crustal deformation using GPS/acoustic technique at the Suruga trough, Japan

    Science.gov (United States)

    Kenji, Y.; Tadokoro, K.; Ikuta, R.; Nagai, S.; Watanabe, T.; Okuda, T.; Sayanagi, K.

    2012-12-01

    Observation of seafloor crustal deformation using the GPS/acoustic technique started from the study by Spiess et al. (1998). In Japan, this type of observation has been carried out at the subduction margins, e.g., Japan trench, Suruga trough, and Nankai trough. At the present, the accuracy of seafloor positioning is 1 to several centimeters for each epoch. Velocity vectors at seafloor point are estimated through repeating observations. Sato et al. (2011) and Kido et al. (2011) observed clear crustal deformations during the 2011 Tohoku-Oki earthquake, at the seafloor. Ito et al. (2011) and Iinuma et al. (2012) derived coseismic slip distributions using GPS/acoustic data and on-land GPS data. To observe seafloor crustal deformation is crucial because great subduction earthquakes, such as Tokai and Tonankai earthquakes, often have hypocenter under the seafloor. We observed seafloor crustal deformation at two observation points across the Suruga trough from 2005 to 2011 to investigate interplate locking condition at the source area of the anticipated great subduction, Tokai, earthquake. An east point of the Suruga trough (SNE) was observed 13 times, and an west point of the Suruga trough (SNW) was observed 14 times. We reanalyzed all previous observation data to improve the data quality through the following three processes: 1) Muting reflected waves from the sea surface or vessel body in the acoustic data. 2) Removing the acoustic data during the vessel's attitude data exceed a criteria. 3) Removing the acoustic data during the GPS satellite tracking condition was unstable. The travel-time residual RMS in one epoch improved by 0.27 ms through the improvement of data quality. We estimated the displacement velocity vectors with relative to the Amurian plate on the basis of the result of repeated observation. The estimated displacement velocity vectors at SNE and SNW are 42±8 mm/y to N94±3W direction and 54±17 mm/y to N94±4W direction, respectively. Taking the error

  7. Utilizing Non-Equilibrium Thermodynamics and Reactive Transport to Model CH4 Production from the Nankai Trough Gas Hydrate Reservoir

    Directory of Open Access Journals (Sweden)

    Khadijeh Qorbani

    2017-07-01

    Full Text Available The ongoing search for new sources of energy has brought natural gas hydrate (NGH reservoirs to the forefront of attention in both academia and the industry. The amount of gas reserves trapped within these reservoirs surpasses all of the conventional fossil fuel sources explored so far, which makes it of utmost importance to predict their production potential and safety. One of the challenges facing those attempting to analyse their behaviour is that the large number of involved phases make NGHs unable to ever reach equilibrium in nature. Field-scale experiments are expensive and time consuming. However, computer simulations have now become capable of modelling different gas production scenarios, as well as production optimization analyses. In addition to temperature and pressure, independent thermodynamic parameters for hydrate stabilization include the hydrate composition and concentrations for all co-existing phases. It is therefore necessary to develop and implement realistic kinetic models accounting for all significant routes for dissociation and reformation. The reactive transport simulator makes it easy to deploy nonequilibrium thermodynamics for the study of CH4 production from hydrate-bearing sediments by considering each hydrate-related transition as a separate pseudo reaction. In this work, we have used the expanded version of the RetrasoCodeBright (RCB reactive transport simulator to model exploitation of the methane hydrate (MH reservoir located in the Nankai Trough, Japan. Our results showed that higher permeabilities in the horizontal direction dominated the pressure drop propagation throughout the hydrate layers and affected their hydrate dissociation rates. Additionally, the comparison of the vertical well versus the horizontal well pattern indicated that hydrate dissociation was slightly higher in the vertical well scenario compared to the horizontal.

  8. Baseline seismic survey for the 2nd offshore methane hydrate production test in the Eastern Nankai Trough

    Science.gov (United States)

    Teranishi, Y.; Inamori, T.; Kobayashi, T.; Fujii, T.; Saeki, T.; Takahashi, H.; Kobayashi, F.

    2017-12-01

    JOGMEC carries out seismic monitoring surveys before and after the 2nd offshore methane hydrate (MH) production test in the Eastern Nankai Trough and evaluates MH dissociation behavior from the time-lapse seismic response. In 2016, JOGMEC deployed Ocean Bottom Cable (OBC) system provided by OCC in the Daini Atsumi Knoll with water depths of 900-1100 m. The main challenge of the seismic survey was to optimize the cable layout for ensuring an effective time-lapse seismic detectability while overcoming the following two issues: 1. OBC receiver lines were limited to only two lines. It was predicted that the imaging of shallow reflectors would suffer from lack of continuity and resolution due to this limitation of receiver lines. 2. The seafloor and shallow sedimentary layers including monitoring target are dipping to the Northwest direction. It was predicted that the refection points would laterally shift to up-dip direction (Southeast direction). In order to understand the impact of the issues above, the seismic survey was designed with elastic wave field simulation. The reflection seismic survey for baseline data was conducted in August 2016. A total of 70 receiver stations distributed along one cable were deployed successfully and a total of 9952 shots were fired. After the baseline seismic survey, the hydrophone and geophone vertical component datasets were processed as outlined below: designaturing, denoising, surface consistent deconvolution and surface consistent amplitude correction. High-frequency imaging with Reverse Time Migration (RTM) was introduced to these data sets. Improvements in imaging from the RTM are remarkable compared to the Kirchhoff migration and the existing Pre-stack time migration with 3D marine surface seismic data obtained and processed in 2002, especially in the following parts. The MH concentrated zone which has complex structures. Below the Bottom Simulating Reflector (BSR) which is present as a impedance-contrast boundary

  9. Pump apparatus including deconsolidator

    Energy Technology Data Exchange (ETDEWEB)

    Sonwane, Chandrashekhar; Saunders, Timothy; Fitzsimmons, Mark Andrew

    2014-10-07

    A pump apparatus includes a particulate pump that defines a passage that extends from an inlet to an outlet. A duct is in flow communication with the outlet. The duct includes a deconsolidator configured to fragment particle agglomerates received from the passage.

  10. Optical modulator including grapene

    Science.gov (United States)

    Liu, Ming; Yin, Xiaobo; Zhang, Xiang

    2016-06-07

    The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

  11. On the Probability Density Function of the Crest to Trough Heights of Waves and on the Physics of Extreme Waves Including Results from Hurricane Camille.

    Science.gov (United States)

    1984-03-01

    bridge the gap between nonlinear periodic waves and their properties and the random nonlinear wave found in nature. Mansard and Funke (1982) needed to...14 illustrate attempts by Mansard and Funke C 1982 ) to generate various wave forms at a measurement point 22.8 m from the generator. The left hand...5.0 10.0 15.0 20.0 0 5.0 10.0 15.0 20.0 TIME (S) *FIGURE 14 Desired and Measured Transients obtained in a Wave Tank. Redrawn from Mansard and Funke

  12. Active spreading processes at ultraslow mid-ocean ridges: Unusual seismicity at the amagmatic Lena Trough, Arctic Ocean

    Science.gov (United States)

    Läderach, Christine; Schlindwein, Vera; Riedel, Carsten

    2010-05-01

    Lena Trough is the southern continuation of the ultraslow-spreading Gakkel Ridge and with its position in the Fram Strait between Greenland and Spitsbergen it is the only deep-sea gateway to the Arctic Ocean. DFG funded Emmy Noether group 'Mid-Ocean Volcanoes and Earthquakes' located at Alfred Wegener Institute for Polar and Marine Research is focusing on the seismicity of ultraslow spreading ridges and is especially interested in Lena Trough as an ultraslow spreading ridge in a developing stage. The southern Lena Trough shows similarities to the northern Red Sea spreading centre which is in the early stage of development from continental to oceanic rift. Cochran postulated in 2003 that the continental crust within the water-covered Red Sea is less than 10 km thick and that the northern part of the Red Sea rift spreads ultraslow as well. At Lena Trough an actively spreading mid-ocean ridge with a narrow rift valley has already developed but continental crust lies within a short distance. Lena Trough is extending from 83°N/5°W to 80.3°N/2°W where it passes into the transform fault of the Spitsbergen Fracture Zone. The geometry of Lena Trough and certain asymmetric structures in the rift valley indicate oblique spreading and mostly tectonic and amagmatic rifting. There are several topographic highs west of the ridge axis which could be bounded by deep faults with normal faulting or detachment character exposing mantle material at the surface. Seismicity at the Lena Trough shows apparently the same asymmetric character with epicenters of teleseismically recorded earthquakes concentrating predominantly west of the ridge axis. The most frequent focal mechanism of the earthquakes within the rift valley is normal faulting, whereas strike-slip faults occur in the Spitsbergen Fracture Zone. We relocalized teleseismic earthquakes recorded from May 1973 to April 2009 in the region using a refined localization algorithm and could confirm systematic asymmetry in the

  13. Topography and distribution of central graben in Okinawa Trough Miyoko Section

    Science.gov (United States)

    Luan, X.; Qin, Y.

    2006-05-01

    Based on geophysical data obtained by R/V "Science 1¡± of Institute of Oceanology, Chinese Academy of Sciences (IOCAS) and R/V "Xiangyanghong 9¡± of State Oceanic Administration (SOA) in a 200 km long area of Okinawa Trough Miyoko Section recent years, we show the topography and distribution of central graben in great detail for the first time. Central graben within Miyoko Section is separated into 9 discontinuous segments by strike slip faults, from north to south namely Laoshan, Huangdao, Jiaonan, Jiaozhou, Pingdu, Jimo, Laixi, Chengyang and Licang Segment respectively, and shows a dextral echelon pattern in general. By cross shapes, three types of central graben can be distinguished, namely U type, V type and half graben. U type is the most common central graben among those found in our study area. The depth of central graben is from 40 m to 250 m, wide from 6 km to 14 km, length from 17 km to 33 km. The largest water depth of Miyoko Section is 2244.4 m, found at the east side of north end bottom of Chengyang Segment (125°19.3'E, 25°49.8'N). Within the dextral echelon pattern, Huangdao, Chengyang, Licang Segment moves to the west relatively to Laoshan, Laixi and Chengyang Segment respectively, showing a local sinistral echelon pattern. The striking direction of central graben is N60°E roughly, that is 15° more to the east comparing to the striking of the Okinawa Trough. There is 6 km long overlap distance between Laixi Segment and Chengyang Segments, simile with an overlap spreading center in the Mid-Ocean Ridge. Two volcanic chains, the central axis volcanic chain which located within the central graben and the island arc volcanic chain which located at the west side of Ryukyu Island Arc are clearly found in this section. The island volcanic chain has a good continuity, but the axis volcanic chain is sporadic comparatively. From seismic profile, we understand that the development of central axis volcanic chain is after the development of central graben

  14. The upper Cenomanian-lower Turonian of the Preafrican Trough (Morocco): Platform configuration and palaeoenvironmental conditions

    Science.gov (United States)

    Lebedel, V.; Lézin, C.; Andreu, B.; Ettachfini, El M.; Grosheny, D.

    2015-06-01

    A synthetic study was carried out based on sedimentological, palaeontological, geochemical and mineralogical data of the upper Cenomanian-lower Turonian carbonate platform of the Preafrican Trough (eastern Morocco) in order to (1) propose a 3D representation of the platform and constrain the temporal framework of the dysoxic/anoxic episodes recorded during the OAE2, (2) define and discuss the prevailing climate on the platform during this period, and (3) make comparisons with other Cenomanian-Turonian platforms. During the late Cenomanian, both before and during the CCIE (Cenomanian Carbon Isotope Excursion), the platform displayed an east-west polarity. Three third-order sequences of transgression-regression can be defined. Dysoxic conditions were developed in the sediments and the bottom waters of the deepest environment (mid- to outer-ramp setting), in the western part of the platform. Well-oxygenated waters were present in the eastern part of the platform (peritidal zone to mid-ramp environment). The climate was arid before the CCIE, becoming warm with contrasted seasons during the CCIE. This climate is associated with a low palaeoproductivity over the entire platform, along with the presence of photozoan followed by heterozoan carbonate-producers, as found also in other parts of the Saharan platform. However, such conditions are not in accordance with many studies which suggest a wet climate during the CCIE, leading to intense chemical weathering of the continent favouring the appearance of high palaeoproductivity at a global scale and the establishment of dysoxic/anoxic conditions. In the Preafrican Trough, poorly-oxygenated waters spread outwards from the deep basins and covered the platform in response to sea-level rise. Many disturbances are recorded in the platform succession during the early Turonian, after the CCIE. Indeed, just after the C/T boundary, the development of an outer-ramp environment over the entire Preafrican Trough reflects flooding of

  15. Sedimentological Properties of Natural Gas Hydrates-Bearing Sands in the Nankai Trough and Mallik Areas

    Science.gov (United States)

    Uchida, T.; Tsuji, T.; Waseda, A.

    2009-12-01

    The Nankai Trough parallels the Japanese Island, where extensive BSRs have been interpreted from seismic reflection records. High resolution seismic surveys have definitely indicated gas hydrate distributions, and drilling the MITI Nankai Trough wells in 2000 and the METI Tokai-oki to Kumano-nada wells in 2004 have revealed subsurface gas hydrate in the eastern part of Nankai Trough. In 1998 and 2002 Mallik wells were drilled at Mackenzie Delta in the Canadian Arctic that also clarified the characteristics of gas hydrate-dominant sandy layers at depths from 890 to 1110 m beneath the permafrost zone. During the field operations, the LWD and wire-line well log data were continuously obtained and plenty of gas hydrate-bearing sand cores were recovered. Subsequence sedimentological and geochemical analyses performed on those core samples revealed the crucial geologic controls on the formation and preservation of natural gas hydrate in sediments. Pore-space gas hydrates reside in sandy sediments mostly filling intergranular porosity. Pore waters chloride anomalies, core temperature depression and core observations on visible gas hydrates confirm the presence of pore-space gas hydrates within moderate to thick sandy layers, typically 10 cm to a meter thick. Sediment porosities and pore-size distributions were obtained by mercury porosimetry, which indicate that porosities of gas hydrate-bearing sandy strata are approximately 45 %. According to grain size distribution curves, gas hydrate is dominant in fine- to very fine-grained sandy strata. Gas hydrate saturations are typically up to 80 % in pore volume throughout most of the hydrate-dominant sandy layers, which are estimated by well log analyses as well as pore water chloride anomalies. It is necessary for investigating subsurface fluid flow behaviors to evaluate both porosity and permeability of gas hydrate-bearing sandy sediments, and the measurements of water permeability for them indicated that highly saturated

  16. Tsunami Scenario in the Nankai Trough, Japan, Based on the GPS-A and GNSS Velocities

    Science.gov (United States)

    Bock, Y.; Watanabe, S. I.; Melgar, D.; Tadokoro, K.

    2017-12-01

    We present two local tsunami scenarios for the Nankai trough, Japan, an area of significant seismic risk, using GPS-A and GNSS velocities and two different plate interface geometries to better assess the slip deficit rate. We expand on the work of Yokota et al. [2016, Nature] by: (1) Adding seafloor data collected by Nagoya University [Tadokoro et al., 2012 GRL] at the Kumano basin, (2) Aligning the geodetic data to the Nankai block (forearc sliver) to the tectonic model of Loveless and Meade [2010 JGR] - the earlier work ignored block boundaries such as the Median Tectonic Line (MTL) and may have overestimated the slip deficit rate, (3) Considering two different plate interface geometries - it is essential to use the accurate depth of the plate interface, especially for the offshore region where the faults are located near the observation sites, (4) Estimating and correcting for the postseismic displacements of the 2004 southeastern off the Kii Peninsula earthquakes (MJMA 7.1, 7.4). Based upon the refined model, we calculate the coseismic displacements and tsunami wave propagation assuming that a hundred years of constant slip deficit accumulation is released instantaneously. We used the open source software GeoClaw v5.3.1, which solves the two-dimensional shallow water equations with the finite volume technique [LeVeque, 2002 Cambridge University Press], for the local tsunami scenarios. We present the expected tsunami propagation models and wave profiles based on the geodetically-derived distribution of slip, stressing the importance of identifying fault locations and geometries. The location of the downdip edge of the coseismic rupture is essential to assess whether the coastal area would subside or not. The sensitivity to the plate interface geometries is increased in the near-trough region. From the point of view of disaster prevention, subsidence at the southern coast would heighten the tsunami runup distance (e.g., at gauges in Shimotsu and Irago). Further

  17. Performance analysis of an Integrated Solar Combined Cycle using Direct Steam Generation in parabolic trough collectors

    International Nuclear Information System (INIS)

    Montes, M.J.; Rovira, A.; Munoz, M.; Martinez-Val, J.M.

    2011-01-01

    Highlights: → Solar hybridization improves the performance of CCGT in a very hot and dry weather. → The scheme analyzed is a DSG parabolic trough field coupled to the Rankine cycle. → An annual simulation has been carried out for two locations: Almeria and Las Vegas. → Economical analysis shows that this scheme is a cheaper way to exploit solar energy. → For that, solar hybridization must be limited to a small fraction of the CCGT power. - Abstract: The contribution of solar thermal power to improve the performance of gas-fired combined cycles in very hot and dry environmental conditions is analyzed in this work, in order to assess the potential of this technique, and to feature Direct Steam Generation (DSG) as a well suited candidate for achieving very good results in this quest. The particular Integrated Solar Combined Cycle (ISCC) power plant proposed consists of a DSG parabolic trough field coupled to the bottoming steam cycle of a Combined Cycle Gas Turbine (CCGT) power plant. For this analysis, the solar thermal power plant performs in a solar dispatching mode: the gas turbine always operates at full load, only depending on ambient conditions, whereas the steam turbine is somewhat boosted to accommodate the thermal hybridization from the solar field. Although the analysis is aimed to studying such complementary effects in the widest perspective, two relevant examples are given, corresponding to two well-known sites: Almeria (Spain), with a mediterranean climate, and Las Vegas (USA), with a hot and dry climate. The annual simulations show that, although the conventional CCGT power plant works worse in Las Vegas, owing to the higher temperatures, the ISCC system operates better in Las Vegas than in Almeria, because of solar hybridization is especially well coupled to the CCGT power plant in the frequent days with great solar radiation and high temperatures in Las Vegas. The complementary effect will be clearly seen in these cases, because the thermal

  18. Clouds and troughs of total electron content detected with the ionospheric weather index

    Science.gov (United States)

    Gulyaeva, Tamara

    2016-07-01

    The ionospheric weather W index has been developed with the different thresholds of change in the F2 layer peak electron density NmF2 (proportional to foF2 critical frequency) or total electron content TEC relative their quiet reference for quantifying the ionosphere variability. The thresholds of DTEC=log(TEC/TECq) are selected for the positive and negative logarithm of TEC ratio to the quiet reference median, TECq, at any given location on the Earth. The global W-index maps are produced from Global Ionospheric Maps of Total Electron Content, GIM-TEC, and provided online at http://www.izmiran.ru/services/iweather/ and http://www.iololab.org/. Based on W-index maps, Catalogues of the ionospheric storms and sub-storms are produced available for the users. The second generation of the ionospheric weather indices, designated V index, is recently introduced and applied for the retrospective study of GIM-TEC variability during 1999-2015. Using sliding-window statistical analysis, moving daily-hourly TEC median TECq for 15 preceding days with estimated variance bounds are obtained at cells of GIM-TEC. The ionosphere variability index, V, is expressed in terms of ΔTEC deviation from the median normalized by the standard deviation STD. V index segmentation is introduced from Vn=-4 in step of 1 to Vp=4 specifying TEC storm if an instant TEC is outside of TECq+-1STD. The global maps of V index allow distinguish the clouds of enhanced TEC (positive storm signatures) and troughs of TEC depletion (negative storm signatures) as compared to the background quiet reference TECq map. It is found that the large-scale TEC clouds and troughs are observed in space all over the world constituting up to 20-50 percent of cells of GIM-TEC. The time variation of these plasma patches is partly following to geomagnetic SSC storm onset. As concerns the interplanetary and the solar wind, SW, sources of the ionospheric storms the TEC storms are observed both with IMF and SW precursors and

  19. The performance analysis of the Trough Concentrating Solar Photovoltaic/Thermal system

    International Nuclear Information System (INIS)

    Li, M.; Li, G.L.; Ji, X.; Yin, F.; Xu, L.

    2011-01-01

    Research highlights: → A 2 m 2 Trough Concentrating Photovoltaic/Thermal (TCPV/T) system is built, a single crystalline silicon solar cell array, a polycrystalline silicon cell array, a Super cell array and a GaAs cell array are respectively used in the experiments. → Another 10 m 2 TCPV/T system using the GaAs cell array and a concentrating silicon cell array are also constructed and characterized. → The economic performance analysis show the electricity generating cost of the TCPV/T system with the concentrating silicon cell array can catch up with flat-plate PV system. -- Abstract: The electrical and thermal performance of a 2 m 2 Trough Concentrating Photovoltaic/Thermal (TCPV/T) system with an energy flux ratio 10.27 are characterized by experiments. A single crystalline silicon solar cell array, a polycrystalline silicon cell array, a Super cell array and a GaAs cell array are respectively used in the experiments. The experimental results show that the electrical performance of the system with the GaAs cell array is better than that of crystal silicon solar cell arrays. The superior output performance of the GaAs cell array mainly benefits from its lower series resistance. But the thermal performances of the system using the single crystal silicon solar cell array and the polycrystalline silicon solar cell array are better. It results from the widths of the two types of cells in the system close to that of the focal line. Another 10 m 2 TCPV/T system with an energy flux ratio of 20 using the GaAs cell array and a concentrating silicon cell array are also constructed and characterized. The experimental results indicate that the photoelectric efficiency of the GaAs cell array is 23.83%, and the instantaneous electrical efficiency and thermal efficiency of the system are 9.88% and 49.84% respectively. While the instantaneous electrical efficiency and thermal efficiency of the system using the low-cost concentrating silicon cell array are 7.51% and 42

  20. Heat Flow Variation along the Nankai Trough Floor Correlated with the Structure of the Shikoku Basin Oceanic Crust

    Science.gov (United States)

    Yamano, M.; Kawada, Y.; Gao, X.

    2016-12-01

    Surface heat flow observed on the floor of the Nankai Trough, near the trench axis, is highly variable and does not well correspond to the seafloor age of the incoming Philippine Sea plate (Shikoku Basin). Recent detailed measurements between 133.5°E and 137°E revealed that heat flow on the trough floor significantly varies along the trough. The most conspicuous variation is found around 136°E. Heat flow is extremely high and variable between 135°E and 136°E, much higher than the value estimated from the age. On the east of 136°E, heat flow gradually decreases eastward over 50 km to the value nearly consistent with the age with no appreciable scatter. Elevated heat flow on the trough floor can be attributed to vigorous fluid circulation in a permeable layer (aquifer) in the subducted oceanic crust, which efficiently transports heat upward along the plate interface (Spinelli and Wang, 2008). The heat flow variation around 136°E may therefore arise from variation in the permeability structure of the crustal aquifer. A probable cause of the heterogeneity in the aquifer permeability is a structure boundary in the incoming Shikoku Basin, the boundary between the younger part on the west formed by spreading in NE-SW direction and the older part on the east formed by E-W spreading. It is located around 136°E, about the same place as the heat flow distribution boundary. A possible additional source of variation in the permeability structure is the geometry of the subducted Philippine Sea plate. A prominent bend in the subducted plate between 135°E and 136°E, which corresponds to the high heat flow area on the trough floor, may have fractured the oceanic crust and enhanced the aquifer permeability. We evaluated the influence of variations in the aquifer permeability on the thermal structure through 3D numerical modelling using a high thermal-conductivity proxy for heat transport by fluid flow. A sharp along-strike change in the permeability of the subducted

  1. Structural characteristics around the frontal thrust along the Nankai Trough revealed by bathymetric and seismic reflection survey

    Science.gov (United States)

    Yamashita, M.; Nakanishi, A.; Moore, G. F.; Kodaira, S.; Nakamura, Y.; Miura, S.; Kaneda, Y.

    2016-12-01

    Great earthquakes with tsunamis with recurrence intervals of 100-200 years have occurred along the Nankai Trough near central Japan where the Shikoku Basin is subducting with thick sediments on the Philippine Sea plate. To predict the exact height of the tsunami on the coast region generated by these large ruptures, it is important to estimate the vertical deformation that occurs on the seaward end of the rupture area. Recent drilling results have also yielded evidence not only of splay faults that generate tsunamigenic rupture, but also new evidence of tsunamigenic rupture along the frontal thrust at the trench axis in the Nankai Trough. In order to understand the deformation around the frontal thrust at the trench axis, we conducted a dense high-resolution seismic reflection survey with 10-20 km spacing over 1500 km of line length during 2013 and 2014. Clear seismic reflection images of frontal thrusts in the accretionary prism and subducting Shikoku Basin, image deformation along the trench axis between off Muroto Cape and off Ashizuri Cape. The cumulative displacement along the frontal thrust and second thrust are measured from picked distinct reflectors in depth-converted profiles. The average value of cumulative displacement of the frontal thrust is more than 100 m within 2 km depth beneath the seafloor. The location of highest displacement of 300 m displacement agree with the seaward end of slip distribution of the 1946 Nankai event calculated by numerical simulations. We also evaluate the seaward structure for understanding the future rupture distribution. The protothrust zone (PTZ) consisting of many incipient thrusts is identifiable in the portion of trough-fill sediments seaward of the frontal thrust. In order to emphasize the characteristics of frontal thrust and PTZ, we construct the detailed relief image for focusing on the lineated slope of the PTZ at the trough axis. Although our surveys covered a part of Nankai seismogenic zone, it is important to

  2. Increased water contamination and grow-out Pekin duck mortality when raised with water troughs compared to pin-metered water lines using a United States management system

    Science.gov (United States)

    Schenk, A.; Porter, A. L.; Alenciks, E.; Frazier, K.; Best, A. A.; Fraley, S. M.; Fraley, G. S.

    2016-01-01

    Controversy has developed as to whether or not pin-metered water lines or water troughs are more appropriate for Pekin ducks. We hypothesized that water troughs would show improved duck body conditions and environmental quality compared to pin-metered water lines. To test this hypothesis, we housed ducks in 2 barns, one with water lines and one with water troughs. Water troughs were constructed to meet RSPCA guidelines for number and density of ducks and with recently described verandas. Ducks were divided into 4 pens per barn (n = 1,000 ducks/pen). The study was then repeated (n = 8 pens per water source) in a cross-over design so the barns each contained the opposite water source to the first experiment. We scored the ducks’ body condition using an established scoring rubric and analyzed using SAS Proc GLM-Mix as binomial data. Ducks housed with water troughs showed higher (thus worse condition; P duck mortality using a Student t test for both water sources each week. We found that the water troughs showed higher iron (P Ducks housed with water troughs used greater (P = 0.001) volumes of water compared to ducks housed with water lines. Ducks with water troughs also showed a greater percent (P = 0.008) mortality at all ages compared to ducks with water lines. These data suggest that water troughs may not be beneficial for duck welfare and could adversely impact both environment and duck or human health. PMID:26769272

  3. Exergetic and Thermoeconomic Analyses of Solar Air Heating Processes Using a Parabolic Trough Collector

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Hernández-Román

    2014-08-01

    Full Text Available This paper presents a theoretical and practical analysis of the application of the thermoeconomic method. A furnace for heating air is evaluated using the methodology. The furnace works with solar energy, received from a parabolic trough collector and with electricity supplied by an electric power utility. The methodology evaluates the process by the first and second law of thermodynamics as the first step then the cost analysis is applied for getting the thermoeconomic cost. For this study, the climatic conditions of the city of Queretaro (Mexico are considered. Two periods were taken into account: from July 2006 to June 2007 and on 6 January 2011. The prototype, located at CICATA-IPN, Qro, was analyzed in two different scenarios i.e., with 100% of electricity and 100% of solar energy. The results showed that thermoeconomic costs for the heating process with electricity, inside the chamber, are less than those using solar heating. This may be ascribed to the high cost of the materials, fittings, and manufacturing of the solar equipment. Also, the influence of the mass flow, aperture area, length and diameter of the receiver of the solar prototype is a parameter for increasing the efficiency of the prototype in addition to the price of manufacturing. The optimum design parameters are: length is 3 to 5 m, mass flow rate is 0.03 kg/s, diameter of the receiver is around 10 to 30 mm and aperture area is 3 m2.

  4. Shallow hydrothermal regime of the East Brawley and Glamis known geothermal resource areas, Salton Trough, California

    Energy Technology Data Exchange (ETDEWEB)

    Mase, C.W.; Sass, J.H.; Brook, C.A.; Munroe, R.J.

    1981-01-01

    Thermal gradients and thermal conductivities were obtained in real time using an in situ heat-flow technique in 15 shallow (90 to 150 m) wells drilled between Brawley and Glamis in the Imperial Valley, Southern California. The in situ measurements were supplemented by follow-up conventional temperature logs in seven of the wells and by laboratory measurements of thermal conductivity on drill cuttings. The deltaic sedimentary material comprising the upper approx. 100 m of the Salton Trough generally is poorly sorted and high in quartz resulting in quite high thermal conductivities (averaging 2.0 Wm/sup -1/ K/sup -1/ as opposed to 1.2 to 1.7 for typical alluvium). A broad heat-flow anomaly with maximum of about 200 mWm/sup -2/ (approx. 5 HFU) is centered between Glamis and East Brawley and is superimposed on a regional heat-flow high in excess of 100 mWm/sup -2/ (> 2.5 HFU). The heat-flow high corresponds with a gravity maximum and partially with a minimum in electrical resistivity, suggesting the presence of a hydrothermal system at depth in this area.

  5. Velocity profiles from borehole seismic in a methane hydrate bearing interval in the eastern Nankai Trough

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K.; Katayama, A.; Yamamoto, H.; Armstrong, P. [Schlumberger, Sagamihara (Japan); Murray, D. [Schlumberger Oilfield Services, Beijing (China); Fukuhara, M. [Schlumberger Moscow Research, Moscow (Russian Federation); Inamori, T.; Saeki, T. [Japan Oil, Gas and Metals National Corp., Chiba (Japan)

    2008-07-01

    In this study, offset vertical seismic profile (OVSP) surveys were conducted to determine seismic velocity profiles for a gas hydrate-bearing interval in the eastern Nankai trough. The survey was used to acquire converted shear waves as well as a 0 offset (ZVSP) survey. The velocity profiles were used to identify and characterize the hydrate deposits in the interval. The study also evaluated the performance of a borehole seismic and sonic measuring tool. An analysis of the OVSP data demonstrated the presence of mode conversion points at the top of the interval as well as at the top and the bottom of a hydrate-concentrated zone. A travel time inversion and parametric inversion process was then used to estimate compressional and shear wave velocities from the shear and direct waves obtained from the ZVSP. Interval velocities from the VSP were then compared with velocities obtained from a sonic log. Results of the comparison indicated that interval velocity profiles increased in the hydrate-bearing zone and decreased at the base of the zone. Seismic and sonic velocities obtained using the tools showed good agreement with each other. However, significant differences were observed in compressional velocities. Velocity discrepancies in the seismic and sonic surveys were attributed to sensitivities related to existing free gas in the area. The borehole seismic tool also acquired additional information in the presence of low saturation gases. It was concluded that a combination of compressional and shear wave data can be used to characterize formation properties. 8 refs., 14 figs.

  6. Delineation of methane hydrate concentrated zone using 3D seismic data in the eastern Nankai Trough

    Energy Technology Data Exchange (ETDEWEB)

    Saeki, T.; Fujii, T.; Inamori, T.; Kobayashi, T.; Hayashi, M.; Nagakubo, S.; Takano, O. [Japan Oil, Gas and Metals National Corp., Mihama-ku, Chiba (Japan). Technology Research and Development Dept.

    2008-07-01

    Methane hydrates are ice-like material compounds consisting of methane and water molecules that are stable under low-temperature and high-pressure conditions. Underground storage of methane hydrate in deepwater and permafrost regions has been investigated as a future energy resource. The Research Consortium for Methane Hydrate Resources in Japan has been conducting an exploration study in the eastern Nankai Trough since 2001. Seismic surveys, multi-well drilling campaigns and other geological surveys have shown that methane hydrate reserves were created by turbidite sand layers. The methane hydrate bearing zones have been categorized into (1) methane hydrate concentrated zones, and (2) methane hydrate bearing zones other than concentrated zones. An optimal interpretation workflow was developed to delineate methane hydrate concentrated zones. The workflow involved an evaluation and integration of 4 indicators, notably (1) a bottom-simulating reflector (BSR), (2) a turbidite sequence, (3) a strong seismic reflector, and (4) a relatively higher interval velocity. More than 10 methane hydrate concentrated zones were identified and their rock volume was successfully evaluated. The results were used for the resource assessment of the study area. The authors noted that the methods introduced in this study could correspond to prospect extraction in conventional oil and gas exploration. 13 refs., 8 figs.

  7. Resource assessment of methane hydrate in the eastern Nankai Trough, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, T.; Saeki, T.; Kobayashi, T.; Inamori, T.; Hayashi, M.; Takano, O.; Takayama, T.; Kawasaki, T.; Nagakubo, S.; Nakamizu, M.; Yokoi, K. [Japan Oil, Gas and Metals National Corp., Mihama-ku, Chiba (Japan). Technology and Research Center

    2008-07-01

    This study investigated the methane hydrate (MH) in the Nankai Trough offshore Japan as a potential natural gas resource. The resource assessment of MH was determined from the Ministry of Economy, Trade and Industry (METI) exploratory test wells Tokai-oki to Kumano-nada. Logging-while-drilling (LWD) campaigns were launched at 16 sites, coring at 4 sites and wirelogging at 2 sites. This study used high resolution 2D/3D seismic data and introduced a new concept for the MH concentrated zone and applied it to resource assessment. MH bearing layers in the survey area were classified into 2 categories, notably MH concentrated zones and MH bearing layers other than relatively thin, low saturated MH layers. The total amount of methane gas in place was estimated to be 40 tcf as Pmean value (10 tcf as P90, 82 tcf as P10). More than 10 prospective MH concentrated zones were extracted. They were characterized by high resistivity well logs, strong seismic reflectors, high p-wave interval velocity and turbidite deposits delineated by sedimentary facies analysis. The total gas in place for MH concentrated zones was estimated to be 20 tcf (half of the total amount) as Pmean value. Sensitivity analysis revealed that the net-to-gross ratio and methane pore saturation have higher sensitivity than other parameters. As such, they are important for further detail analysis. 22 refs., 3 tabs., 9 figs.

  8. Rapid sedimentation and overpressure in shallow sediments of the Bering Trough, offshore southern Alaska

    Science.gov (United States)

    Daigle, Hugh; Worthington, Lindsay L.; Gulick, Sean P. S.; Van Avendonk, Harm J. A.

    2017-04-01

    Pore pressures in sediments at convergent margins play an important role in driving chemical fluxes and controlling deformation styles and localization. In the Bering Trough offshore Southern Alaska, extreme sedimentation rates over the last 140 kyr as a result of glacial advance/retreats on the continental shelf have resulted in elevated pore fluid pressures in slope sediments overlying the Pamplona Zone fold and thrust belt, the accretionary wedge resulting from subduction of the Yakutat microplate beneath the North American Plate. Based on laboratory experiments and downhole logs acquired at Integrated Ocean Drilling Program Site U1421, we predict that the overpressure in the slope sediments may be as high as 92% of the lithostatic stress. Results of one-dimensional numerical modeling accounting for changes in sedimentation rate over the last 130 kyr predicted overpressures that are consistent with our estimates, suggesting that the overpressure is a direct result of the rapid sedimentation experienced on the Bering shelf and slope. Comparisons with other convergent margins indicate that such rapid sedimentation and high overpressure are anomalous in sediments overlying accretionary wedges. We hypothesize that the shallow overpressure on the Bering shelf/slope has fundamentally altered the deformation style within the Pamplona Zone by suppressing development of faults and may inhibit seismicity by focusing faulting elsewhere or causing deformation on existing faults to be aseismic. These consequences are probably long-lived as it may take several million years for the excess pressure to dissipate.

  9. Possible climate preconditioning on submarine landslides along a convergent margin, Nankai Trough (NE Pacific)

    Science.gov (United States)

    Kremer, Katrina; Usman, Muhammed O.; Satoguchi, Yasufumi; Nagahashi, Yoshitaka; Vadakkepuliyambatta, Sunil; Panieri, Giuliana; Strasser, Michael

    2017-12-01

    Submarine landslides are major agents of sediment mass transfer from the shallow to deep sea. Due to their rapid emplacement and tsunamigenic potential, such landslides are significant geohazards for society and off- and on-shore infrastructure. The relationship between climate change and the occurrence of submarine landslides is widely debated. However, there is a lack of continuous long-term submarine landslide records with which to comprehensively understand the relationship between climate-driven forces and submarine landslide occurrence. Here, using oxygen isotope stratigraphy in combination with tephrochronology, we date a 1 Myr continuous record of six landslide deposits (at 13.0-14.2, 323-339, 372-384, 394-413, 508-521, and 857-867 ka) recorded in a slope basin of the Nankai Trough subduction zone, off-shore Japan, which represents the major outcome of this study. The ages of the six landslides coincide mostly with interglacial periods. Thus, we propose that climate forcing might act as a preconditioning factor for slope instability in this active tectonic region.[Figure not available: see fulltext.

  10. Norwich Technologies' Advanced Low-Cost Receivers for Parabolic Troughs

    Energy Technology Data Exchange (ETDEWEB)

    Stettenheim, Joel [Norwich Technologies, White River Junction, VT (United States); McBride, Troy O. [Norwich Technologies, White River Junction, VT (United States); Brambles, Oliver J. [Norwich Technologies, White River Junction, VT (United States); Cashin, Emil A. [Norwich Technologies, White River Junction, VT (United States)

    2013-12-31

    This report summarizes the successful results of our SunShot project, Advanced Low-Cost Receivers for Parabolic Troughs. With a limited budget of $252K and in only 12 months, we have (1) developed validated optical and thermal models and completed rigorous optimization analysis to identify key performance characteristics as part of developing first-generation laboratory prototype designs, (2) built optical and thermal laboratory prototypes and test systems with associated innovative testing protocols, and (3) performed extensive statistically relevant testing. We have produced fully functioning optical and thermal prototypes and accurate, validated models shown to capture important underlying physical mechanisms. The test results from the first-generation prototype establish performance exceeding the FOA requirement of thermal efficiency >90% for a CSP receiver while delivering an exit fluid temperature of > 650 °C and a cost < $150/kWth. Our vacuum-free SunTrap receiver design provides improvements over conventional vacuum-tube collectors, allowing dramatic reductions in thermal losses at high operating temperature.

  11. Gravity modeling of the Muertos Trough and tectonic implications (north-eastern Caribbean)

    Science.gov (United States)

    Granja, Bruna J.L.; Muñoz-Martín, A.; ten Brink, Uri S.; Carbó-Gorosabel, Andrés; Llanes, Estrada P.; Martín-Dávila, J.; Cordoba-Barba, D.; Catalan, Morollon M.

    2010-01-01

    The Muertos Trough in the northeast Caribbean has been interpreted as a subduction zone from seismicity, leading to infer a possible reversal subduction polarity. However, the distribution of the seismicity is very diffuse and makes definition of the plate geometry difficult. In addition, the compressive deformational features observed in the upper crust and sandbox kinematic modeling do not necessarily suggest a subduction process. We tested the hypothesized subduction of the Caribbean plate's interior beneath the eastern Greater Antilles island arc using gravity modeling. Gravity models simulating a subduction process yield a regional mass deficit beneath the island arc independently of the geometry and depth of the subducted slab used in the models. This mass deficit results from sinking of the less dense Caribbean slab beneath the lithospheric mantle replacing denser mantle materials and suggests that there is not a subducted Caribbean plateau beneath the island arc. The geologically more realistic gravity model which would explain the N-S shortening observed in the upper crust requires an overthrusted Caribbean slab extending at least 60 km northward from the deformation front, a progressive increase in the thrusting angle from 8?? to 30?? reaching a maximum depth of 22 km beneath the insular slope. This new tectonic model for the Muertos Margin, defined as a retroarc thrusting, will help to assess the seismic and tsunami hazard in the region. The use of gravity modeling has provided targets for future wide-angle seismic surveys in the Muertos Margin. ?? 2010 Springer Science+Business Media B.V.

  12. [Survival of VTEC O157 and non-O157 in water troughs and bovine feces].

    Science.gov (United States)

    Polifroni, Rosana; Etcheverría, Analía I; Arroyo, Guillermo H; Padola, Nora L

    2014-01-01

    Verotoxin-producing Escherichia coli (VTEC) is the etiologic agent of hemolytic-uremic syndrome (HUS), which typically affects children ranging in age from six months to five years old. Transmission is produced by consumption of contaminated food, by direct contact with animals or the environment and from person to person. In previous studies we determined that the environment of a dairy farm is a non-animal reservoir; thus, we proposed to study the survival of 4 VTEC isolates (O20:H19; O91:H21; O157:H7 and O178:H19) in sterile water troughs and bovine feces by viable bacteria count and detection of virulence genes by PCR. It was demonstrated that the survival of different VTEC isolates (O157 and non-O157) varied in terms of their own characteristics as well as of the environmental conditions where they were found. The main differences between isolates were their survival time and the maximal counts reached. The competitive and adaptive characteristics of some isolates increase the infection risk for people that are visiting or working on a farm, as well as the risk for reinfection of the animals and food contamination. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  13. Biomarkers, carbon isotopic composition and source rock potentials of Awgu coals, middle Benue trough, Nigeria

    Science.gov (United States)

    Adedosu, Taofik A.; Sonibare, Oluwadayo O.; Tuo, Jincai; Ekundayo, Olusegun

    2012-05-01

    Coal and carbonaceous shale samples were collected from two boreholes (BH 94 and BH 120) in Awgu formation of Middle Benue Trough, Nigeria. Source rock potentials of the samples were studied using biomarkers and carbon isotopic composition. Biomarkers in the aliphatic fractions in the samples were studied using Gas Chromatography-Mass Spectrometry (GC-MS). The Carbon isotope analysis of individual n-alkanes in the aliphatic fraction was performed using Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometer (GC-IRMS). The abundance of hopanes, homohopanes (C31-C35), and C29 steranes in the samples indicate terrestrial plant, phytoplankton and cyanobacteria contributions to the organic matter that formed the coal. High (Pr/Ph) ratio (3.04-11.07) and isotopic distribution of individual alkanes showed that the samples consisted of mixed terrestrial/marine organic matter deposited under oxic condition in lacustrine-fluvial/deltaic depositional environment. The maturity parameters derived from biomarker distributions showed that the samples are in the main phase of oil window.

  14. The magma plumbing system in the Mariana Trough back-arc basin at 18° N

    Science.gov (United States)

    Lai, Zhiqing; Zhao, Guangtao; Han, Zongzhu; Huang, Bo; Li, Min; Tian, Liyan; Liu, Bo; Bu, Xuejiao

    2018-04-01

    Mafic magmas are common in back-arc basin, once stalled in the crust, these magmas may undergo different evolution. In this paper, compositional and textural variations of plagioclase as well as mineral-melt geothermobarometry are presented for basalts erupted from the central Mariana Trough (CMT). These data reveal crystallization conditions and we attempt a reconstruction of the magma plumbing system of the CMT. Plagioclase megacrysts, phenocrysts, microphenocrysts, microlites, olivine, spinel, and clinopyroxene have been recognized in basalt samples, using BSE images and compositional features. The last three minerals are homogeneous as microphenocrysts. Mineral-melt barometry indicates that plagioclase crystals crystallized and eventually grew into phenocrysts and megacrysts in mush zone with depth of 5-9 km, in which the normal zoning plagioclases crystallized in the interval of various batches of basic magma recharging. Plagioclase megacrysts and phenocrysts were dissolved and/or resorbed, when new basic magmas injected into the mush zone near Moho depth. It is inferred that magma extracted from the mush zone, and adiabatically ascended via different pathways. Some basaltic magmas underwent plagioclase and clinopyroxene microphenocrysts crystallization in low-pressure before eruption. Plagioclase microlites and outermost rims probably crystallized after eruption.

  15. Thermal Energy Recovery through Optimal Salt concentration in a Parabolic Trough Systems

    Directory of Open Access Journals (Sweden)

    Ramsurn Rikesh

    2018-01-01

    Full Text Available Making a PVT system hybrid is to support the use of thermal and electrical energy simultaneously or independently, to control the thermal effect to improve electrical efficiency or vice-versa. This project makes use of the Parabolic Trough design with emphasis on making the system to be sustainable and also increasing the thermal efficiency of the system. Polystyrene and acrylic foam is utilized to maximize the heat retention capability of the system. To power, the pump that moves the heat transfer fluid (tested with salt water proportions within the copper tube, a set of solar PV panel is to support its power demand making it sustainable. The closed loop setup designed achieved an improved thermal efficiency level of 66.2%, which contributes to having a reliable heat energy source for applications such as hot showers. The novel setup design also makes use of PV cells to support other energy demands through power electronic control designs. Using a similar heat dissipation technique, a novel setup has been designed to improve the voltage supply by making use of liquid cooling and translucent glass PV panels. Cooling the PV panel restored up to 11.7% of its rated voltage supply. This is achieved by keeping the PV panels within its best thermal operating conditions using an energy efficient electronically controlled cooling system.

  16. Geochemical characteristics of hydrothermal sediments from Iheya North Knoll in the Okinawa Trough

    Science.gov (United States)

    Hu, Qiannan; Zhang, Xin; Jiang, Fuqing; Wang, Bing; Luan, Zhendong; Chen, Chang'an; Yan, Jun

    2017-07-01

    Thirty sediment subsamples were recovered from the Iheya North hydrothermal field (with an average of 38 m away from the hydrothermal vent) in the middle Okinawa Trough. Samples were obtained by the ROV (Remote Operated Vehicle) Faxian during the virgin cruise of the R/V Kexue in 2014 with the application of push cores. The chemical compositions of the sediments show that the hydrothermal sediments near the hydrothermal vent are mainly composed of SO3, ZnO and Fe2O3. Moreover, the hydrothermal sediments are also highly enriched in Pb, As, Sb, Hg, Se, Ag, Ba, Mo and Cd comparing with previous analysis results. On the other hand, the concentrations of Sr, Hg and Ag in studied sediments are strongly and positively correlated, these elements can be used as an hydrothermal indicator. In addition, a factor analysis of the sediments suggested that the sediments were mainly influenced by hydrothermal origin, and terrestrial and biogenic input are limited in studied area. It is also suggested that different stages of crystallization were involved in the formation of hydrothermal chimney from factor analysis.

  17. Fault zone characteristics and basin complexity in the southern Salton Trough, California

    Science.gov (United States)

    Persaud, Patricia; Ma, Yiran; Stock, Joann M.; Hole, John A.; Fuis, Gary S.; Han, Liang

    2016-01-01

    Ongoing oblique slip at the Pacific–North America plate boundary in the Salton Trough produced the Imperial Valley (California, USA), a seismically active area with deformation distributed across a complex network of exposed and buried faults. To better understand the shallow crustal structure in this region and the connectivity of faults and seismicity lineaments, we used data primarily from the Salton Seismic Imaging Project to construct a three-dimensional P-wave velocity model down to 8 km depth and a velocity profile to 15 km depth, both at 1 km grid spacing. A VP = 5.65–5.85 km/s layer of possibly metamorphosed sediments within, and crystalline basement outside, the valley is locally as thick as 5 km, but is thickest and deepest in fault zones and near seismicity lineaments, suggesting a causative relationship between the low velocities and faulting. Both seismicity lineaments and surface faults control the structural architecture of the western part of the larger wedge-shaped basin, where two deep subbasins are located. We estimate basement depths, and show that high velocities at shallow depths and possible basement highs characterize the geothermal areas.

  18. A study of panoramic focal trough for the six-year-old child

    International Nuclear Information System (INIS)

    Kim, Sang Yeon; Choi, Hang Moon; Han, Jin Woo; Lee, Sul Mi

    2004-01-01

    To make a focal trough (image layer) for an average maxillary dental arch of 6-year-old Korean in panoramic radiography. Phantom for the maxillary dental arch was designed using intercanine width, intermolar width, tooth size, and interdental spacing to record the data of 6-year-old child. The characteristics of pre-corrected panoramic machine (for adult) was evaluated using the phantom, resolution test pattern for margin of the image layer, and metal ball for the center of the image layer. Panoramic image layer of the child was developed by means of decreasing the speed of film-cassette and positioning the phantom backwards, and then the characteristics of post-corrected panoramic machine (for child) were reevaluated. At post-corrected panoramic image layer, beam projection angles at all interdental areas increased for about 2.6 - 3.8 .deg., the position of the image layer was shifted toward the rotation center for about 2.5 mm at the deciduous central incisior area. The width of image layer decreased at all areas. Increased beam projection angle will reduce the disadvantage of tooth overlap, and the same form between the center of the image layer and dental arch will improve image resolution.

  19. The Characteristics of Fluid Potential in Mud Diapirs Associated with Gas Hydrates in the Okinawa Trough

    Directory of Open Access Journals (Sweden)

    Ning Xu

    2006-01-01

    Full Text Available Many mud diapirs have been identified in the southern Okinawa Trough from a seismic survey using R/V KEXUE I in 2001. The movement and accumulation of free gas related to mud diapirs are discussed in detail by an analysis of fluid potential which is based upon velocity data. It can be found that free gas moves from the higher fluid potential strata to the lower ones and the gas hydrate comes into being during free gas movement meeting the proper criteria of temperature and pressure. In fact, gas hydrates have been found in the upper layers above the mud diapirs and in host rocks exhibiting other geophysical characteristics. As the result of the formation of the gas hydrate, the free gas bearing strata are enclosed by the gas hydrate bearing strata. Due to the high pressure anomalies of the free gas bearing strata the fluid potential increases noticeably. It can then be concluded that the high fluid potential anomaly on the low fluid potential background may be caused by the presence of the free gas below the gas hydrate bearing strata.

  20. Small-Sized Parabolic Trough Collector System for Solar Dehumidification Application: Design, Development, and Potential Assessment

    Directory of Open Access Journals (Sweden)

    Ghulam Qadar Chaudhary

    2018-01-01

    Full Text Available The current study presents a numerical and real-time performance analysis of a parabolic trough collector (PTC system designed for solar air-conditioning applications. Initially, a thermodynamic model of PTC is developed using engineering equation solver (EES having a capacity of around 3 kW. Then, an experimental PTC system setup is established with a concentration ratio of 9.93 using evacuated tube receivers. The experimental study is conducted under the climate of Taxila, Pakistan in accordance with ASHRAE 93-1986 standard. Furthermore, PTC system is integrated with a solid desiccant dehumidifier (SDD to study the effect of various operating parameters such as direct solar radiation and inlet fluid temperature and its impact on dehumidification share. The experimental maximum temperature gain is around 5.2°C, with the peak efficiency of 62% on a sunny day. Similarly, maximum thermal energy gain on sunny and cloudy days is 3.07 kW and 2.33 kW, respectively. Afterwards, same comprehensive EES model of PTC with some modifications is used for annual transient analysis in TRNSYS for five different climates of Pakistan. Quetta revealed peak solar insolation of 656 W/m2 and peak thermal energy 1139 MJ with 46% efficiency. The comparison shows good agreement between simulated and experimental results with root mean square error of around 9%.

  1. Troughs on Martian Ice Sheets: Analysis of Their Closure and Mass Balance

    Science.gov (United States)

    Fountain, A.; Kargel, J.; Lewis, K.; MacAyeal, D.; Pfeffer, T.; Zwally, J.

    2000-01-01

    At the Copenhagen workshop on Martian polar processes, Ralf Greve commented that the flow regime surrounding scarps and troughs of the Martian polar ice sheets cannot be modeled using traditional "plan view" ice-sheet models. Such models are inadequate because they typically use reduced equations that embody certain simplifications applicable only to terrestrial ice sheets where the upper ice sheet surface is smooth. In response to this suggestion, we have constructed a 2-dimensional, time dependent "side view" (two spatial dimensions: one horizontal, one vertical) model of scarp closure that is designed to overcome the difficulties described by Greve. The purpose of the model is to evaluate the scales of stress variation and styles of flow closure so as to estimate errors that may be encountered by "plan view" models. We show that there may be avenues whereby the complications associated with scarp closure can be overcome in "plan view" models through appropriate parameterizations of 3-dimensional effects. Following this, we apply the flow model to simulate the evolution of a typical scarp on the North Polar Cap of Mars. Our simulations investigate: (a) the role of "radiation trapping" (see our companion abstract) in creating and maintaining "spiral-like" scarps on the ice sheet, (b) the consequences of different flowlaws and ice compositions on scarp evolution and, in particular, scarp age, and (c) the role of dust and debris in scarp evolution.

  2. Performance Evaluation of Dual-axis Tracking System of Parabolic Trough Solar Collector

    Science.gov (United States)

    Ullah, Fahim; Min, Kang

    2018-01-01

    A parabolic trough solar collector with the concentration ratio of 24 was developed in the College of Engineering; Nanjing Agricultural University, China with the using of the TracePro software an optical model built. Effects of single-axis and dual-axis tracking modes, azimuth and elevating angle tracking errors on the optical performance were investigated and the thermal performance of the solar collector was experimentally measured. The results showed that the optical efficiency of the dual-axis tracking was 0.813% and its year average value was 14.3% and 40.9% higher than that of the eat-west tracking mode and north-south tracking mode respectively. Further, form the results of the experiment, it was concluded that the optical efficiency was affected significantly by the elevation angle tracking errors which should be kept below 0.6o. High optical efficiency could be attained by using dual-tracking mode even though the tracking precision of one axis was degraded. The real-time instantaneous thermal efficiency of the collector reached to 0.775%. In addition, the linearity of the normalized efficiency was favorable. The curve of the calculated thermal efficiency agreed well with the normalized instantaneous efficiency curve derived from the experimental data and the maximum difference between them was 10.3%. This type of solar collector should be applied in middle-scale thermal collection systems.

  3. Design of a single flat null-screen for testing a parabolic trough solar collector

    Science.gov (United States)

    Moreno-Oliva, Víctor Iván; Campos-García, Manuel; Román-Hernández, Edwin; Santiago-Alvarado, Agustín

    2014-11-01

    We present a null-screen design for testing the shape quality of the reflecting surface of a parabolic trough solar collector (PTSC). This technique is inexpensive, the whole surface is tested at once, and it is easy to implement. For this, we propose the design of a flat null-screen perpendicular to the optical axis of the PTSC in such a way that it allows testing of the full aperture; we compute the caustic associated with the reflected light rays on the desired surface and analyze the parameters that determine the null-screen dimensions. Additionally, we perform a numerical simulation to analyze the accuracy of the method by introducing random displacement errors into the measured data. Accuracies >0.35 mrad were found to evaluate the quality of surfaces with this method. The errors in the determination of the coordinates of the centroids of the reflected images must be measured with an accuracy >0.5 pixels, and the errors in the coordinates of the spots of the null-screen must be <0.5 mm.

  4. Dynamic Modeling of the Solar Field in Parabolic Trough Solar Power Plants

    Directory of Open Access Journals (Sweden)

    Lourdes A. Barcia

    2015-11-01

    Full Text Available Parabolic trough solar power plants use a thermal fluid to transfer thermal energy from solar radiation to a water-steam Rankine cycle in order to drive a turbine that, coupled to an electrical generator, produces electricity. These plants have a heat transfer fluid (HTF system with the necessary elements to transform solar radiation into heat and to transfer that thermal energy to the water-steam exchangers. In order to get the best possible performance in the Rankine cycle and, hence, in the thermal plant, it is necessary that the thermal fluid reach its maximum temperature when leaving the solar field (SF. Also, it is mandatory that the thermal fluid does not exceed the maximum operating temperature of the HTF, above which it degrades. It must be noted that the optimal temperature of the thermal fluid is difficult to obtain, since solar radiation can change abruptly from one moment to another. The aim of this document is to provide a model of an HTF system that can be used to optimize the control of the temperature of the fluid without interfering with the normal operation of the plant. The results obtained with this model will be contrasted with those obtained in a real plant.

  5. Characteristics of hydrocarbons in sediment core samples from the northern Okinawa Trough.

    Science.gov (United States)

    Huang, Xin; Chen, Shuai; Zeng, Zhigang; Pu, Xiaoqiang; Hou, Qinghua

    2017-02-15

    Sediment core samples from the northern Okinawa Trough (OT) were analyzed to determine abundances and distributions of hydrocarbons by gas chromatography-mass spectrometer (GC-MS). The results show that the n-alkanes in this sediment core conform to a bimodal distribution, and exhibit an odd-to-even predominance of high molecular weights compared to an even-to-odd predominance in low molecular weight n-alkanes with maxima at C 16 and C 18 . The concentrations of bitumen, alkanes and polyaromatic hydrocarbons (PAHs) were higher in samples S10-07 than all others. Three maturity parameters as well as the ratios between parent phenanthrenes (Ps) and methylphenanthrenes (MPs) in samples S10-07 and S10-17 were higher. The distribution and composition of hydrocarbons in sample S10-07 suggest that one, or several, undetected hydrothermal fields may be present in the region of this sediment core. Results also suggest that volcanism may be the main reason for the observed distribution and composition of hydrocarbons in S10-17 sample. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Particle Directional Conveyance under Longitudinal Vibration by considering the Trough Surface Texture: Numerical Simulation Based on the Discrete Element Method

    Directory of Open Access Journals (Sweden)

    Huazhi Chen

    2018-01-01

    Full Text Available Particles can move directionally in a trough with finlike asperities under longitudinal vibrations. Here, we present an analysis of the particle conveyance mechanism and the influence of the asperity shape on the particle conveyance capacity by employing a numerical simulation based on the discrete element method (DEM. A dynamic-static matching method is proposed to characterize the three microcontact parameters in the simulation: the restitution coefficient, static friction coefficient, and rolling friction coefficient. The simulation shows that the asymmetric force induced by the finlike asperities and its cumulative effect over time lead to the particle directional conveyance. The conveyance velocity increases with increasing vibration time and is related to the median coordination number. The asperity height and slope inclination angles determine the trough shape and distance between two asperities directly. An undersized or oversized distance reduces the steady conveyance velocity. We find the optimal distance to be between one and two particle diameters.

  7. Suitability analysis of waste rock application in hydric reclamation in the natural water-bearing subsidence troughs in OKR

    International Nuclear Information System (INIS)

    Pertile, E.

    2007-01-01

    The paper deals with a suitability analysis of waste rock application in hydric reclamation on the basis of studying its impact on water quality in the natural water-bearing subsidence troughs. The evaluation was carried out in sixteen localities where waste rock had been used in the past for the purposes of bank system improvement. Within the evaluation of waste rock impact on the hydrochemical character of water in the subsidence troughs the values of geochemical background were identified. In order to compare the impact of waste rock on the quality of water, changes in the hydrochemical parameters were monitored in the localities without waste rock banking, with partial (maximum 1/2 circumference) and complete waste rock banking. (author)

  8. Back-Arc Opening in the Western End of the Okinawa Trough Revealed From GNSS/Acoustic Measurements

    Science.gov (United States)

    Chen, Horng-Yue; Ikuta, Ryoya; Lin, Cheng-Horng; Hsu, Ya-Ju; Kohmi, Takeru; Wang, Chau-Chang; Yu, Shui-Beih; Tu, Yoko; Tsujii, Toshiaki; Ando, Masataka

    2018-01-01

    We measured seafloor movement using a Global Navigation Satellite Systems (GNSS)/Acoustic technique at the south of the rifting valley in the western end of the Okinawa Trough back-arc basin, 60 km east of northeastern corner of Taiwan. The horizontal position of the seafloor benchmark, measured eight times between July 2012 and May 2016, showed a southeastward movement suggesting a back-arc opening of the Okinawa Trough. The average velocity of the seafloor benchmark shows a block motion together with Yonaguni Island. The westernmost part of the Ryukyu Arc rotates clockwise and is pulled apart from the Taiwan Island, which should cause the expansion of the Yilan Plain, Taiwan. Comparing the motion of the seafloor benchmark with adjacent seismicity, we suggest a gentle episodic opening of the rifting valley accompanying a moderate seismic activation, which differs from the case in the segment north off-Yonaguni Island where a rapid dyke intrusion occurs with a significant seismic activity.

  9. Structure of the poleward wall of the trough and the inclination of the geomagnetic field above the EISCAT radar

    Directory of Open Access Journals (Sweden)

    D. G. Jones

    Full Text Available A special high-resolution routine of the EISCAT radar has been used to investigate the structure and development of the poleward wall of a deep trough in electron density. The feature was tracked by the radar during a 7-hour period under very quiet geomagnetic conditions. The field-aligned nature of the structure enabled an estimate to be made of the inclination of the geomagnetic field above EISCAT that was in good agreement with the current model. Observations of narrow field-aligned enhancements in electron temperature demonstrated that the wall of this trough is a dynamic feature, reforming regularly as the electron density responds on a time scale of tens of minutes to energy input from soft-particle precipitation.

  10. Structure of the poleward wall of the trough and the inclination of the geomagnetic field above the EISCAT radar

    Directory of Open Access Journals (Sweden)

    D. G. Jones

    1997-06-01

    Full Text Available A special high-resolution routine of the EISCAT radar has been used to investigate the structure and development of the poleward wall of a deep trough in electron density. The feature was tracked by the radar during a 7-hour period under very quiet geomagnetic conditions. The field-aligned nature of the structure enabled an estimate to be made of the inclination of the geomagnetic field above EISCAT that was in good agreement with the current model. Observations of narrow field-aligned enhancements in electron temperature demonstrated that the wall of this trough is a dynamic feature, reforming regularly as the electron density responds on a time scale of tens of minutes to energy input from soft-particle precipitation.

  11. The Nankai Trough earthquake tsunamis in Korea: Numerical studies of the 1707 Hoei earthquake and physics-based scenarios

    Science.gov (United States)

    Kim, S.; Saito, T.; Fukuyama, E.; Kang, T. S.

    2016-12-01

    Historical documents in Korea and China report abnormal waves in the sea and rivers close to the date of the 1707 Hoei earthquake, which occurred in the Nankai Trough, off southwestern Japan. This indicates that the tsunami caused by the Hoei earthquake might have reached Korea and China, which suggests a potential hazard in Korea from large earthquakes in the Nankai Trough. We conducted tsunami simulations to study the details of tsunamis in Korea caused by large earthquakes. We employed the 1707 Hoei earthquake source model and physics-based scenarios of anticipated earthquake in the Nankai subduction zone. We also considered the effect of horizontal displacement on tsunami generation. Our simulation results from the Hoei earthquake model and the anticipated earthquake models showed that the maximum tsunami height along the Korean coast was less than 0.5 m. Even though the tsunami is not life-threatening, the effect of larger earthquakes should be still considered.

  12. Second Generation Novel High Temperature Commercial Receiver & Low Cost High Performance Mirror Collector for Parabolic Solar Trough

    Energy Technology Data Exchange (ETDEWEB)

    Stettenheim, Joel [Norwich Technologies, White River Junction, VT (United States)

    2016-02-29

    Norwich Technologies (NT) is developing a disruptively superior solar field for trough concentrating solar power (CSP). Troughs are the leading CSP technology (85% of installed capacity), being highly deployable and similar to photovoltaic (PV) systems for siting. NT has developed the SunTrap receiver, a disruptive alternative to vacuum-tube concentrating solar power (CSP) receivers, a market currently dominated by the Schott PTR-70. The SunTrap receiver will (1) operate at higher temperature (T) by using an insulated, recessed radiation-collection system to overcome the energy losses that plague vacuum-tube receivers at high T, (2) decrease acquisition costs via simpler structure, and (3) dramatically increase reliability by eliminating vacuum. It offers comparable optical efficiency with thermal loss reduction from ≥ 26% (at presently standard T) to ≥ 55% (at high T), lower acquisition costs, and near-zero O&M costs.

  13. Implications for differences in LWD resistivity measurements in NanTroSEIZE boreholes within the Nankai Trough, Offshore Japan

    Science.gov (United States)

    Martin, K. M.; Gulick, S. P.; Flemings, P. B.; Tudge, J.

    2009-12-01

    IODP Expedition 314, the first drilling cruise of the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE), acquired logging while drilling (LWD) data at five sites, including gamma ray, sonic velocity and resistivity logs. Density, photoelectric factor (PEF) and neutron porosity logs were also acquired at sites C0001 and C0002. Five different resistivity logs were acquired by LWD on this expedition, including shallow, medium and deep button resistivities, a ring resistivity and resistivity at the bit. These logs all have different depths of investigation and sampling intervals. As such, the effects of fluid invasion, washouts and variations in the formation itself vary from log to log. The differences between the various readings, particularly between those with the deepest and shallowest depths of penetration can indicate the degree of invasion or washout in the borehole. This degree of invasion may in turn shed some light on the relative permeability of the formation itself. The differences in the five resistivity readings acquired on Expedition 314 do not consistently vary directly or inversely with caliper readings, implying that differences between the deep and shallow button resistivities are not simply related to washouts, but likely also contain a signal related to formation invasion. We have investigated the variations in the differences between resistivities, with an emphasis on the occurrence of variations not associated with washouts. Site C0002 in the Kumano Basin provides a complete sedimentary section in which to examine how fluctuations in the differences between resistivity logs correspond to lithological changes. The basin sediments are interpreted to be primarily sandy-silty turbidites based on gamma ray log values and variations, as well as density, PEF and resistivity log values. A particularly clay-rich log unit (interpreted based on gamma ray and PEF log values) at the base of the basin sediments corresponds to an area of similarity

  14. A post-partum single-dose TDF/FTC tail does not prevent the selection of NNRTI resistance in women receiving pre-partum ZDV and intrapartum single-dose nevirapine to prevent mother-to- child HIV-1 transmission.

    Science.gov (United States)

    Samuel, Reshmi; Paredes, Roger; Parboosing, Raveen; Moodley, Pravi; Singh, Lavanya; Naidoo, Anneta; Gordon, Michelle

    2015-10-01

    Although the rates of vertical transmission of HIV in the developing world have improved to around 3% in countries like South Africa, resistance to antiretrovirals (ARV) used in Prevention of Mother-to-Child transmission (pMTCT) strategies may thwart such outcomes and affect the efficacy of future ARV regimens in mothers and children. This study conducted in Durban, South Africa, between 2010 and 2013 found a high rate of nevirapine (NVP) resistance among women receiving Zidovudine (AZT) from 14 weeks gestation, single dose nevirapine (sd NVP) at the onset of labor and a single dose of coformulated Tenofovir/Emtricitabine (TDF/FTC) postpartum. Using Sanger sequencing, high and intermediate levels of nevirapine (NVP) resistance were detected in 15/44 (34%) and in 1/44 (2%) of women tested, respectively. Most subjects selected the K103N mutation (22% (10/45) of all patients and 66% (10/15) of those with high-level NVP resistance). Such rate of NVP resistance is comparable to studies where only sd NVP was used. In conclusion, a post-partum single-dose TDF/FTC tail does not prevent the selection of NNRTI resistance in women receiving pre-partum ZDV and intrapartum sd NVP to prevent mother-to-child HIV-1 transmission. © 2015 Wiley Periodicals, Inc.

  15. Analysis of fine ELF wave structures observed poleward from the ionospheric trough by the low-altitude satellite DEMETER

    Czech Academy of Sciences Publication Activity Database

    Parrot, M.; Nĕmec, F.; Santolík, Ondřej

    2014-01-01

    Roč. 119, č. 3 (2014), s. 2052-2060 ISSN 2169-9380 R&D Projects: GA ČR GAP205/10/2279; GA MŠk LH12231 Institutional support: RVO:68378289 Keywords : trough * EMIC * substorm Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.426, year: 2014 http://onlinelibrary.wiley.com/doi/10.1002/2013JA019557/abstract

  16. Constraints on mantle melt geometries from body wave attenuation in the Salton Trough and Snake River Plain

    Science.gov (United States)

    Byrnes, J. S.; Bezada, M.

    2017-12-01

    Melt can be retained in the mantle at triple junctions between grain boundaries, be spread in thin films along two-grain boundaries, or be organized by shear into elongate melt-rich bands. Which of these geometries is most prevalent is unknown. This ambiguity makes the interpretation of anomalous seismic velocities and quality factors difficult, since different geometries would result in different mechanical effects. Here, we compare observations of seismic attenuation beneath the Salton Trough and the Snake River Plain; two regions where the presence of melt has been inferred. The results suggest that seismic attenuation is diagnostic of melt geometry. We measure the relative attenuation of P waves from deep focus earthquakes using a time-domain method. Even though the two regions are underlain by comparably strong low-velocity anomalies, their attenuation signature is very different. The upper mantle beneath the Salton Trough is sufficiently attenuating that the presence of melt must lower Qp, while attenuation beneath the Snake River Plain is not anomalous with respect to surrounding regions. These seemingly contradictory results can be reconciled if different melt geometries characterize each region. SKS splitting from the Salton Trough suggests that melt is organized into melt-rich bands, while this is not the case for the Snake River Plain. We infer that beneath the Snake River Plain melt is retained at triple junctions between grain boundaries, a geometry that is not predicted to cause seismic attenuation. More elongate geometries beneath the Salton Trough may cause seismic attenuation via the melt-squirt mechanism. In light of these results, we conclude that prior observations of low seismic velocities with somewhat high quality factors beneath the East Pacific Rise and Southern California suggest that melt does not organize into elongate bands across much of the asthenosphere.

  17. Mirror-Image Structural Relationship Between Western Taiwan and Nankai Trough Region, Southwest Japan, and its Significance for Earthquake Forecast

    Science.gov (United States)

    Sugiyama, Y.

    2001-12-01

    Western Taiwan is characterized by west-facing imbricate structure. The westernmost sheet in Taichung area contains a depositional basin (Taichung Basin), structural high (Pleistocene uplands) and frontal thrust (e.g., Changhua Fault) from east to west. Another older sheet underlain by the Chelungpu Fault, a causative fault of the 1999 Chi-Chi Earthquake, has nearly the same tectonic components. The northern tip of each underlying thrust curves eastwards and branches out into several faults. These geologic structures are a mirror image of the structure characterizing the source areas of great earthquakes along the Nankai Trough. This fact indicates that the two regions are controlled by the same tectonics, low-angle oblique subduction, and their mirror-image relationship reflects a left oblique subduction (western Taiwan) and a right oblique one (Nankai Trough). Based on this correlation, eastward bending structure of the northernmost Chelungpu Fault near Houli can be regarded as a segment boundary. In western Taiwan, there are three other eastward bending structures correlative to the segment boundary. They are distributed near Hsihchu, near Minhsiung, and on the north of Tainan. Western Taiwan is divided into five segments 60 to 80 km long by the eastward bending structures. This segment size is nearly a half of the Nankai Trough region (120 to 150 km long) and may regulate the size of future earthquakes resulting from ruptures of these segments. In the Nankai Trough region, faults at the segment boundaries are not likely to rupture independently of reactivation of the main thrusts. In western Taiwan, however, faults at the segment boundaries may have ruptured independently of the faulting of main thrusts during the 1906 Minhsiung, 1935 Hsihchu-Taichung and 1946 Hsinhua earthquakes. This difference between the two regions remains a problem to be solved.

  18. Theoretical and Experimental Optical Evaluation and Comparison of Symmetric 2D CPC and V-Trough Collector for Photovoltaic Applications

    Directory of Open Access Journals (Sweden)

    Damasen Ikwaba Paul

    2015-01-01

    Full Text Available This paper presents theoretical and experimental optical evaluation and comparison of symmetric Compound Parabolic Concentrator (CPC and V-trough collector. For direct optical properties comparison, both concentrators were deliberately designed to have the same geometrical concentration ratio (1.96, aperture area, absorber area, and maximum concentrator length. The theoretical optical evaluation of the CPC and V-trough collector was carried out using a ray-trace technique while the experimental optical efficiency and solar energy flux distributions were analysed using an isolated cell PV module method. Results by simulation analysis showed that for the CPC, the highest optical efficiency was 95% achieved in the interval range of 0° to ±20° whereas the highest outdoor experimental optical efficiency was 94% in the interval range of 0° to ±20°. For the V-tough collector, the highest optical efficiency for simulation and outdoor experiments was about 96% and 93%, respectively, both in the interval range of 0° to ±5°. Simulation results also showed that the CPC and V-trough exhibit higher variation in non-illumination intensity distributions over the PV module surface for larger incidence angles than lower incidence angles. On the other hand, the maximum power output for the cells with concentrators varied depending on the location of the cell in the PV module.

  19. PV systems with passive solar tracking and V-trough concentrators; Photovoltaikanlagen mit passiver Nachfuehrung und V-Trog Konzentratoren

    Energy Technology Data Exchange (ETDEWEB)

    Klotz, F.H. [Fachgebiet Photovoltaische Anlagentechnik, Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany)

    1997-02-01

    Passive tracking and V-trough concentration (PV V-trough) can enhance the array yield (energy yield per installed power) of photovoltaic systems in Europe by 60% to 100% (dependent on site and configuration). By the use of simple techniques, energy costs can be decreased by 20% to 30% relative to conventional fixed-tilt PV systems. This contribution presents the passively tracked PV V-trough concentrator concept. The state-of-the-art of this technology will be demonstrated by results from two systems in Widderstall/Schwaebische Alb and Manfredonia/Apulien. The technical and economic potential of this system concept will be discussed for different climates and system configurations. (orig.) [Deutsch] Passive Nachfuehrung und V-Trog Konzentration koennen die spezifische Energieausbeute (Energieertrag pro installierter Leistung) von Photovoltaikanlagen in Europa etwa 60% bis 100% (je nach Standort und Anlagenkonfiguration) steigern. Durch den Einsatz besonders einfacher Technik koennen damit die Energiegestehungskosten gegenueber konventionellen, festorientierten Photovoltaikanlagen um ca. 20% bis 30% gesenkt werden. Dieser Beitrag stellt das Konzept der passiv nachgefuehrten Photovoltaikanlage mit V-Trog Konzentrator (PV V-Trog) vor. Der Stand der Technik wird anhand der Betriebsergebnisse von realisierten Anlagen in Widderstall/Schwaebische Alb und in Manfredonia/Apulien dargestellt. Das technische und wirtschaftliche Potential dieser Anlagentechnik wird fuer verschiedene Standorte und Systemvarianten aufgezeigt und diskutiert. (orig.)

  20. The formation of gold-rich seafloor sulfide deposits: Evidence from the Beebe hydrothermal vent field, Cayman Trough

    Science.gov (United States)

    Webber, Alexander P.; Roberts, Stephen; Murton, Bramley J.; Mills, Rachel A.; Hodgkinson, Matthew R. S.

    2017-06-01

    The Beebe vent field (BVF) in the Cayman Trough has built an auriferous massive sulfide deposit on the ultraslow spreading mid-Cayman spreading center. The genesis of auriferous sulfide deposits at mid-ocean ridges is not fully understood, although there is a growing recognition that slow and ultraslow spreading centers are conducive to gold mineralization. Analysis of hydrothermal precipitates from the BVF indicates that the highest gold contents are present within "beehive diffusers," which have developed a highly porous pyrrhotite framework. The beehive structure allows vent fluids to effuse slowly while allowing ingress of seawater to cool the fluid. The prevalence of pyrrhotite in the beehive samples, lack of sulfates, association between pyrrhotite and gold grains, and results of thermodynamic modeling suggest gold precipitation occurred under highly reduced conditions even during mixing with seawater. In contrast, high-temperature chimneys, with a single orifice, maintain high temperatures to the primary vent orifice and much of the gold is lost to seawater. Despite this, both chimney types are relatively gold-enriched, which points to a further underlying cause for high gold at the BVF such as interaction of hydrothermal fluids with ultramafic lithologies in the basement. The final gold composition of the deposit is partially controlled by loss of gold during mass-wasting of the material, with gold depletion most prevalent in blocks formed at beehive-type chimneys. The BVF demonstrates that the overall gold content of a massive sulfide deposit is the sum of basement, precipitation, and surface processes.Plain Language SummaryMineral deposits form on the seafloor at hydrothermal vent sites and are rich in metals including copper, zinc, lead, and sometimes precious metals like gold and silver. However, the processes controlling the amount of gold that ends up in these deposits is not clearly understood. In this article we show that as hydrothermal fluid vents

  1. Bottom water oxygenation changes in the northern Okinawa Trough since the last 88ka: Controlled by local hydrology and climate

    Science.gov (United States)

    Zou, Jianjun; Shi, Xuefa; Zhu, Aimei; Bai, Yazhi; Selvaraj, Kandasamy

    2014-05-01

    Dissolved oxygen content in oceanic bottom water is closely related to the surface organic carbon export and subsurface water stratification, regulating the biogeochemical cycles of some key nutrients and trace elements in intermediate and deep water columns. Further, the rate of organic carbon flux to sediments and bottom water oxygen concentration together determine the intensity of reducing conditions in sediments. In this study, we obtain high-resolution geochemical elements (TOC, TN, TS, CaCO3, Cd, U, Mn and Mo) in a radiocarbon (14C) and δ18O dated, sediment core CSH1 collected from the northern Okinawa Trough to reconstruct the history of bottom water redox conditions over 88 ka. Our data revealed the presence of hypoxic bottom water in the northern Okinawa Trough during late MIS5a-early MIS4, Last Glacial Maximum, and the early Last Deglacial intervals. During the Holocene and the early MIS5a, the dissolved oxygen content in bottom water has increased with decreasing water stratification, which was probably caused by the increased upwelling from the bottom in tandem with the climbing of Kuroshio Current and subdued freshwater effect in the northern Okinawa Trough. The reasons that caused the change of dissolved oxygen content in bottom water in the northern Okinawa Trough varied during different periods. The main factors are related to sea level, strengths of East Asian monsoon and the Kuroshio Current, and the shift of Westerly Jet Axis. The semi-closed topography in the northern Okinawa Trough provides a space framework for the presence of anoxia, while the sea level together with the Kuroshio Current, the East Asian monsoon and the Westerly Jet Axis seems to affect the strength of water stratification and the nutrient supply; thereby, regulating the dissolved oxygen exchange between surface and bottom waters. This work was supported by the National Natural Science Foundation of China(Grant No.:40906035,40710069004) and by basic scientific fund for

  2. Sidescan Sonar Imagery of the Escanaba Trough, Southern Gorda Ridge, Offshore Northern California

    Science.gov (United States)

    Ross, Stephanie L.; Zierenberg, Robert A.

    2009-01-01

    This map features sidescan imagery of the northern Escanaba (NESCA) site at the Escanaba Trough, southern Gorda Ridge, offshore northern California. The Escanaba Trough, a largely sediment-covered seafloor spreading center, contains at least six large massive sulfide deposits. It is a slow spreading center (2.5 cm/yr) with axial depths locally exceeding 3,300 m. Discrete igneous centers occur at 5- to 10-km intervals along this slow-spreading ridge. Basaltic magma intrudes the sediment fill of the axial valley, creating uplifted sediment hills, and, in some areas, erupts onto the sea floor. Large massive sulfide deposits occur along the margins of the uplifted sediment hills. The only active hydrothermal system is located on Central Hill where 220 deg C fluids construct anhydrite chimneys on pyrrhotite-rich massive sulfide mounds (Campbell and others, 1994). Central Hill is bounded by both ridge-parallel basement faults and a concentric set of faults that rim the top of the hill and may be associated with sill intrusion. Central Hill was one of the primary drill sites for Ocean Drilling Program (ODP) Leg 169. The sidescan sonar data (mosaics A, B, C, D) were collected aboard the National Oceanic and Atmospheric Administration (NOAA) research vessel Discoverer in the summer of 1996 with a 60-kHz system towed 100 to 200 m above the sea floor. Major faults and contacts are interpreted from the sidescan mosaics and 4.5-kHz seismic profiles collected simultaneously, as well as from previously conducted camera transects and submersible dives. The seismic profiles (lines 9, 11, 13) provide high-resolution subbottom structure and stratigraphy to a depth of about 50 m. In the sidescan images (mosaics A, B, C, D), bright areas denote high-energy returns from hard reflectors such as volcanic flows, sulfide deposits, or seafloor scarps. Dark areas denote low-energy returns and generally signify relatively undisturbed surface sediment. The grid lines mark one-minute intervals

  3. Environmental risks of the gas hydrate field development in the Eastern Nankai Trough

    Science.gov (United States)

    Yamamoto, K.; Nagakubo, S.

    2009-12-01

    To establish any kinds of new energy resources, environmental impacts of the technology should be well understood before full industrial implementation. Methane hydrate (MH), a relatively clean fossil energy with low CO2 and no SOx emission, is not an exception. Because methane gas itself has strong greenhouse gas effect, and methane hydrate is not stable under the atmospheric pressure and room temperature, public image of MH field development is very risky game and potentially disastrous to the global climate. However, the real physics of the MH bearing sediments is far different from such images. MH21 Research Consortium in Japan has studied about the resource assessment and production techniques to develop MH since 2001. As the results, we found several gas hydrate concentrated zones with pore filling type hydrate in sandy layers of turbidite sediment in the Eastern Nankai Trough area off coasts of the Central Japan. The depressurization technique, in the other word, in-situ MH dissociation by water production and natural heat supply from surrounding formation, will be used as the basic method to produce methane gas from MH. Under the conditions, we have evaluated realistic environmental risk of the MH production. Because the most MH found in the Eastern Nankai Trough are composed of biogenic and almost pure methane, there is no concern of sea water contamination by oil releases that is the most common environmental disaster caused by misconducts of the oil industry. Also MH reservoirs there are not pressurized, and blowout of wells during drilling is very unlikely. Endothermic MH dissociation process decreases formation temperature with depressurization, and give negative feedback, then, there is no chance of chain reaction. Heat supply from surrounding formations is necessary for continuous dissociation, but heat transfer in the formations is relatively slow, and the dissociation rate is limited. Once the operation to pump water in boreholes for

  4. Diagenetic evaluation of Pannonian lacustrine deposits in the Makó Trough, southeastern Hungary

    Science.gov (United States)

    Szőcs, Emese; Milovský, Rastislav; Gier, Susanne; Hips, Kinga; Sztanó, Orsolya

    2017-04-01

    The Makó Trough is the deepest sub-basin of the Pannonian Basin. As a possible shale gas and tight gas accumulation the area was explored by several hydrocarbon companies. In this study, we present the preliminary results on the diagenetic history and the porosity evolution of sandstones and shales. Petrographic (optical microscopy, CL, blue light microscopy) and geochemical methods (SEM-EDX, WDX, O and C stable isotopes) were applied on core samples of Makó-7 well (3408- 5479 m). Processes which influenced the porosity evolution of the sandstones were compaction, cementation, mineral replacement and dissolution. The most common diagenetic minerals are carbonates (non-ferroan and Fe-bearing calcite, dolomite and ankerite), clay minerals (kaolinite, mixed layer illite-smectite and chlorite) and other silicates (quartz and feldspar). Initial clay mineral and ductile grain content also influences reservoir quality. The volumetrically most significant diagenetic minerals are calcite and clay minerals. The petrography of calcite is variable (bright orange to dull red luminescence color, pore-filling cement, replacive phases which are occasionally scattered in the matrix). The δ13 C-PDB values of calcite range from 1.7 ‰ to -5.5 ‰, while δ18 O-PDB values range from 0.5 ‰ to -9.1 ‰, no depth related trend was observed. These data suggest that calcite occurs in more generations, i.e. eogenetic pre-compactional and mesogenetic post-compactional. Kaolinite is present in mottles in size similar to detrital grains, where remnants of feldspars can be seen. This indicates feldspar alteration via influx of water rich in organic derived carbon dioxide. Secondary porosity can be observed in carbonates and feldspars at some levels, causing the improvement of the reservoir quality.

  5. Micrinite maceral evidence of hydrocarbon generation in cretaceous coal measures of the middle Benue trough, Nigeria

    International Nuclear Information System (INIS)

    Obaje, N. G.; Ukpabio, E. J.; Funtua, I. I.

    1999-01-01

    Maceral analysis on samples from the coal and coal-bearing strata of the Awgu Formation in the Middle Benue Trough of Nigeria allows the subdivision of the coal beds and inter seam sediments into three different petrographic/coal facies, namely: a vitrinite-fusinite coal facies which is rich in vitrinite, poor in liptinite, with variable amounts of inertinite and low mineral matter content; a trimaceritic coal facies which is rich in vitrinite, liptinite and inertinite with low mineral matter content; and a shaley coal facies which, expectedly, is dominated by mineral matter and has variable amounts of vitrinite, liptinite and inertinite. Micrinite macerals constitute 8.2% and 4.5 on mineral matter-counted basis in samples from the trimaceritic and shaley coal facies respectively. These amounts, in both cases, are considered to be very high. They occur as finely particulate, rounded grains approximately I um in diameter. Most of the micrinite are closely associated with highly reflecting, almost unrecognizable liptinite. The nature and origin of micrinite and its significance to oil and gas generation have been studied extensively. As secondary macerals, they are generally believed to be relics of oil generation from oil-prone macerals, mainly liptinitic and vitrinitic macerals with which they are closely associated. Reflectance measurements on the associated vitrinite macerals indicate a thermal maturity range of 0.74 - 1.25 % Rm. This range corresponds to the zone of oil generation in most minerogenic oil source rocks. In the study area, however, only the trimaceritic coal facies and some parts of the shaley coal facies that are rich in liptinite alongside the associated micrinite macerals are considered to have generated oil. The vitrinite-fusinite coal facies with its high content of humic organic matter (vitrinite + Inertinite) can only generate gas (wet + dry) within the given thermal maturity range

  6. Evidence of displacement-driven maturation along the San Cristobal Trough transform plate boundary

    Science.gov (United States)

    Neely, James S.; Furlong, Kevin P.

    2018-03-01

    The San Cristobal Trough (SCT), formed by the tearing of the Australia plate as it subducts under the Pacific plate near the Solomon Islands, provides an opportunity to study the transform boundary development process. Recent seismicity (2013-2016) along the 280 km long SCT, known as a Subduction-Transform Edge Propagator (STEP) fault, highlights the tearing process and ongoing development of the plate boundary. The region's earthquakes reveal two key characteristics. First, earthquakes at the western terminus of the SCT, which we interpret to indicate the Australia plate tearing, display disparate fault geometries. These events demonstrate that plate tearing is accommodated via multiple intersecting planes rather than a single through-going fault. Second, the SCT hosts sequences of Mw ∼7 strike-slip earthquakes that migrate westward through a rapid succession of events. Sequences in 1993 and 2015 both began along the eastern SCT and propagated west, but neither progression ruptured into or nucleated a large earthquake within the region near the tear. Utilizing b-value and Coulomb Failure Stress analyses, we examine these along-strike variations in the SCT's seismicity. b-Values are highest along the youngest, western end of the SCT and decrease with increasing distance from the tear. This trend may reflect increasing strain localization with increasing displacement. Coulomb Failure Stress analyses indicate that the stress conditions were conducive to continued western propagation of the 1993 and 2015 sequences suggesting that the unruptured western SCT may have fault geometries or properties that inhibit continued rupture. Our results indicate a displacement-driven fault maturation process. The multi-plane Australia plate tearing likely creates a western SCT with diffuse strain accommodated along a network of disorganized faults. After ∼90 km of cumulative displacement (∼900,000 yr of plate motion), strain localizes and faults align, allowing the SCT to host

  7. Sensor for Measuring Hydrogen Partial Pressure in Parabolic Trough Power Plant Expansion Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Glatzmaier, Greg C.; Cooney, Daniel A.

    2017-06-27

    The National Renewable Energy Laboratory and Acciona Energy North America are working together to design and implement a process system that provides a permanent solution to the issue of hydrogen buildup at parabolic trough power plants. We are pursuing a method that selectively removes hydrogen from the expansion tanks that serve as reservoirs for the heat transfer fluid (HTF) that circulates in the collector field and power block components. Our modeling shows that removing hydrogen from the expansion tanks at a design rate reduces and maintains dissolved hydrogen in the circulating HTF to a selected target level. Our collaborative work consists of several tasks that are needed to advance this process concept to a development stage, where it is ready for implementation at a commercial power plant. Our main effort is to design and evaluate likely process-unit operations that remove hydrogen from the expansion tanks at a specified rate. Additionally, we designed and demonstrated a method and instrumentation to measure hydrogen partial pressure and concentration in the expansion-tank headspace gas. We measured hydrogen partial pressure in the headspace gas mixture using a palladium-alloy membrane, which is permeable exclusively to hydrogen. The membrane establishes a pure hydrogen gas phase that is in equilibrium with the hydrogen in the gas mixture. We designed and fabricated instrumentation, and demonstrated its effectiveness in measuring hydrogen partial pressures over a range of three orders of magnitude. Our goal is to install this instrument at the Nevada Solar One power plant and to demonstrate its effectiveness in measuring hydrogen levels in the expansion tanks under normal plant operating conditions.

  8. Development of the Plate Boundary Observatory GPS Low Latency Salton Trough Radio Network

    Science.gov (United States)

    Walls, C.; Miller, S.; Wilson, B.; Lawrence, S.; Arnitz, E.

    2008-05-01

    UNAVCO is developing a 20 GPS station low latency radio network that spans the San Andreas and San Jacinto faults in the region of highest strain in southern California and the narrowest part of the North America-Pacific plate boundary. The Salton Trough Radio Network (STRN) is instrumented with Ethernet bridge Intuicom EB6+ (900 MHz) radios to transmit a high rate low latency data stream from each permanent GPS site for the purpose of the following: 1) telemeter 15 second data (1 MB/day/station) to the Plate Boundary Observatory archive, 2) accommodate the timely download of 1 and 5 sample per second data following large earthquakes (4 MB/hour/station), and 3) test the UStream of 1Hz BINEX and RTCM data. Three of four phases have been completed. Office radio testing yielded transfer rates of 30-50 KB/s with subsecond latency while streaming 1 Hz data. Latency climbed to ~1.8 seconds while simultaneously streaming 1 Hz and downloading hourly 1 and 5 sample per second data files. Field testing demonstrated rates on the order of 30 KB/s. At present the radios are installed and have transfer rates of 10-40 KB/s between sites that span 10-32 km. The final phase will be the installation of the main telemetry relay where master radios will be connected to a high speed ISP near the town of Brawley. The high-rate low latency UStream data will be available to researchers who are developing prototype earthquake early warning systems in Southern California. A goal of the STRN is to make the data available rapidly enough for GPS-derived coseismic and dynamic displacements to be integrated into early warning system earthquake models. The improved earthquake models will better assist emergency response. UStream data will also aid surveyors who wish to use PBO GPS stations as permanent, high-quality base stations in real-time kinematic surveys.

  9. Modelling geothermal conditions in part of the Szczecin Trough – the Chociwel area

    Directory of Open Access Journals (Sweden)

    Miecznik Maciej

    2015-09-01

    Full Text Available The Chociwel region is part of the Szczecin Trough and constitutes the northeastern segment of the extended Szczecin-Gorzów Synclinorium. Lower Jurassic reservoirs of high permeability of up to 1145 mD can discharge geothermal waters with a rate exceeding 250 m3/h and temperatures reach over 90°C in the lowermost part of the reservoirs. These conditions provide an opportunity to generate electricity from heat accumulated in geothermal waters using binary ORC (Organic Rankine Cycle systems. A numerical model of the natural state and exploitation conditions was created for the Chociwel area with the use of TOUGH2 geothermal simulator (i.e., integral finite-difference method. An analysis of geological and hydrogeothermal data indicates that the best conditions are found to the southeast of the town of Chociwel, where the bottom part of the reservoir reaches 3 km below ground. This would require drilling two new wells, namely one production and one injection. Simulated production with a flow rate of 275 m3/h, a temperature of 89°C at the wellhead, 30°C injection temperature and wells being 1.2 km separated from each other leads to a small temperature drop and moderate requirements for pumping power over a 50 years’ time span. The ORC binary system can produce at maximum 592.5 kW gross power with the R227ea found as the most suitable working fluid. Geothermal brine leaving the ORC system with a temperature c. 53°C can be used for other purposes, namely mushroom growing, balneology, swimming pools, soil warming, de-icing, fish farming and for heat pumps.

  10. Start-up performance of parabolic trough concentrating solar power plants

    Science.gov (United States)

    Ferruzza, Davide; Topel, Monika; Basaran, Ibrahim; Laumert, Björn; Haglind, Fredrik

    2017-06-01

    Concentrating solar power plants, even though they can be integrated with thermal energy storage, are still subjected to cyclic start-up and shut-downs. As a consequence, in order to maximize their profitability and performance, the flexibility with respect to transient operations is essential. In this regard, two of the key components identified are the steam generation system and steam turbine. In general it is desirable to have fast ramp-up rates during the start-up of a power plant. However ramp-up rates are limited by, among other things, thermal stresses, which if high enough can compromise the life of the components. Moreover, from an operability perspective it might not be optimal to have designs for the highest heating rates, as there may be other components limiting the power plant start-up. Therefore, it is important to look at the interaction between the steam turbine and steam generator to determine the optimal ramp rates. This paper presents a methodology to account for thermal stresses limitations during the power plant start up, aiming at identifying which components limit the ramp rates. A detailed dynamic model of a parabolic trough power plant was developed and integrated with a control strategy to account for the start-up limitations of both the turbine and steam generator. The models have been introduced in an existing techno-economic tool developed by the authors (DYESOPT). The results indicated that for each application, an optimal heating rates range can be identified. For the specific case presented in the paper, an optimal range of 7-10 K/min of evaporator heating rate can result in a 1.7-2.1% increase in electricity production compared to a slower component (4 K/min).

  11. Controls on Submarine Canyon Development Along the Eastern Margin of the Rockall Trough

    Science.gov (United States)

    O'Reilly, B. M.; Readman, P. W.; Shannon, P. M.; Jacob, A. B.

    2001-12-01

    Deep towed sidescan sonar data from the Rockall Trough, west of Ireland, provides an example of how shallow sedimentary facies architecture and slope morphology, related to major submarine canyons, evolve in a deep-water basin straddling the transition from a glaciated to a non-glaciated basin margin. In the north (54° to 56° N), glacial influences were overwhelming and a stacked sequence of flow slides is developed on the upper to mid-slope. In steeper regions of the slope, cauliform gully systems are likely to have been produced by gravitational collapse of Quaternary glaciomarine and older sediments close to the steeper headwall regions of incised pre- Quaternary canyons. The input of glacial sediment and the frequency of slope failure events was probably pulsed and forced by palaeoclimatic variations in the North Atlantic during the Pleistocene epoch. A difference in the morphology of the canyons south of 54° N (notably the absence of gully complexes) marks an important change in sedimentological processes and is related to a severe reduction in the supply of glaciomarine sediments southwards along the margin. Channels along this part of the basin margin are deeply incised into consolidated sediments or rock along the lower part of the slope. These channels may be part of geologically ancient system of canyons, which were active during a period of basin margin uplift and later drowned by rapid Tertiary subsidence. Subsequently, they acted as a transport pathway for late Tertiary and Quaternary sediments and for those remobilized by strong Holocene contour currents.

  12. Deepest and hottest hydrothermal activity in the Okinawa Trough: the Yokosuka site at Yaeyama Knoll

    Science.gov (United States)

    Miyazaki, Junichi; Kawagucci, Shinsuke; Makabe, Akiko; Takahashi, Ayu; Kitada, Kazuya; Torimoto, Junji; Matsui, Yohei; Tasumi, Eiji; Shibuya, Takazo; Nakamura, Kentaro; Horai, Shunsuke; Sato, Shun; Ishibashi, Jun-ichiro; Kanzaki, Hayato; Nakagawa, Satoshi; Hirai, Miho; Takaki, Yoshihiro; Okino, Kyoko; Watanabe, Hiromi Kayama; Kumagai, Hidenori; Chen, Chong

    2017-12-01

    Since the initial discovery of hydrothermal vents in 1977, these `extreme' chemosynthetic systems have been a focus of interdisciplinary research. The Okinawa Trough (OT), located in the semi-enclosed East China Sea between the Eurasian continent and the Ryukyu arc, hosts more than 20 known vent sites but all within a relatively narrow depth range (600-1880 m). Depth is a significant factor in determining fluid temperature and chemistry, as well as biological composition. However, due to the narrow depth range of known sites, the actual influence of depth here has been poorly resolved. Here, the Yokosuka site (2190 m), the first OT vent exceeding 2000 m depth is reported. A highly active hydrothermal vent site centred around four active vent chimneys reaching 364°C in temperature, it is the hottest in the OT. Notable Cl depletion (130 mM) and both high H2 and CH4 concentrations (approx. 10 mM) probably result from subcritical phase separation and thermal decomposition of sedimentary organic matter. Microbiota and fauna were generally similar to other sites in the OT, although with some different characteristics. In terms of microbiota, the H2-rich vent fluids in Neuschwanstein chimney resulted in the dominance of hydrogenotrophic chemolithoautotrophs such as Thioreductor and Desulfobacterium. For fauna, the dominance of the deep-sea mussel Bathymodiolus aduloides is surprising given other nearby vent sites are usually dominated by B. platifrons and/or B. japonicus, and a sponge field in the periphery dominated by Poecilosclerida is unusual for OT vents. Our insights from the Yokosuka site implies that although the distribution of animal species may be linked to depth, the constraint is perhaps not water pressure and resulting chemical properties of the vent fluid but instead physical properties of the surrounding seawater. The potential significance of these preliminary results and prospect for future research on this unique site are discussed.

  13. Deepest and hottest hydrothermal activity in the Okinawa Trough: the Yokosuka site at Yaeyama Knoll.

    Science.gov (United States)

    Miyazaki, Junichi; Kawagucci, Shinsuke; Makabe, Akiko; Takahashi, Ayu; Kitada, Kazuya; Torimoto, Junji; Matsui, Yohei; Tasumi, Eiji; Shibuya, Takazo; Nakamura, Kentaro; Horai, Shunsuke; Sato, Shun; Ishibashi, Jun-Ichiro; Kanzaki, Hayato; Nakagawa, Satoshi; Hirai, Miho; Takaki, Yoshihiro; Okino, Kyoko; Watanabe, Hiromi Kayama; Kumagai, Hidenori; Chen, Chong

    2017-12-01

    Since the initial discovery of hydrothermal vents in 1977, these 'extreme' chemosynthetic systems have been a focus of interdisciplinary research. The Okinawa Trough (OT), located in the semi-enclosed East China Sea between the Eurasian continent and the Ryukyu arc, hosts more than 20 known vent sites but all within a relatively narrow depth range (600-1880 m). Depth is a significant factor in determining fluid temperature and chemistry, as well as biological composition. However, due to the narrow depth range of known sites, the actual influence of depth here has been poorly resolved. Here, the Yokosuka site (2190 m), the first OT vent exceeding 2000 m depth is reported. A highly active hydrothermal vent site centred around four active vent chimneys reaching 364°C in temperature, it is the hottest in the OT. Notable Cl depletion (130 mM) and both high H 2 and CH 4 concentrations (approx. 10 mM) probably result from subcritical phase separation and thermal decomposition of sedimentary organic matter. Microbiota and fauna were generally similar to other sites in the OT, although with some different characteristics. In terms of microbiota, the H 2 -rich vent fluids in Neuschwanstein chimney resulted in the dominance of hydrogenotrophic chemolithoautotrophs such as Thioreductor and Desulfobacterium . For fauna, the dominance of the deep-sea mussel Bathymodiolus aduloides is surprising given other nearby vent sites are usually dominated by B. platifrons and/or B. japonicus , and a sponge field in the periphery dominated by Poecilosclerida is unusual for OT vents. Our insights from the Yokosuka site implies that although the distribution of animal species may be linked to depth, the constraint is perhaps not water pressure and resulting chemical properties of the vent fluid but instead physical properties of the surrounding seawater. The potential significance of these preliminary results and prospect for future research on this unique site are discussed.

  14. Crustal Structure in the Southern Rockall Trough from Satellite Gravity Data: Evidence for Sea-floor Spreading

    Science.gov (United States)

    Chappell, A.; Kusznir, N. J.

    2005-05-01

    The southern Rockall Trough south of 57 N has previously been interpreted as either an intra-continental rift floored with highly extended continental crust, or a failed oceanic rift formed by Cretaceous sea floor spreading. Satellite gravity, bathymetry data and seismic estimates of sediment thickness are used to derive crustal basement thickness for the southern Rockall Trough and adjacent regions using a gravity inversion method incorporating a correction for the large negative thermal gravity component present in oceanic and stretched continental lithosphere. The marine Bouguer anomaly, derived from satellite free air gravity (Sandwell & Smith 1997) and Gebco 2003 bathymetry data, is inverted using the method of Oldenberg (1974), incorporating an iteratively applied thermal anomaly correction, to give Moho depth. For oceanic crust the thermal anomaly correction is calculated using isochron ages (Muller et al. 1997) and for continental crust from the beta stretching factors resulting from gravity derived crustal basement thickness and an assumed rift age. When sediment thickness and volcanic addition are assumed to be zero, the resulting upper bound of crustal thickness from the gravity inversion is as little as 10 km in the southern Rockall Trough. A segmented axial thickening of the crust at the centre of the Rockall Trough is predicted, between the Barra volcanic ridge and the Anton Dohrn seamount and is interpreted as having a volcanic origin. Inclusion of a sediment thickness correction in the gravity inversion further reduces predicted crustal thickness. A pseudo-sediment-thickness map has been constructed from the available wide-angle data and incorporated in the gravity inversion. The addition of up to 5.5 km of sediment in the gravity inversion reduces the upper bound of crustal thickness to less than 3 km in some locations. The segmented axial thickening and thin crust shown by the gravity inversion, the lack of intra-basinal faulting, and the volcanic

  15. Efavirenz or nevirapine in three-drug combination therapy with two nucleoside or nucleotide-reverse transcriptase inhibitors for initial treatment of HIV infection in antiretroviral-naïve individuals.

    Science.gov (United States)

    Mbuagbaw, Lawrence; Mursleen, Sara; Irlam, James H; Spaulding, Alicen B; Rutherford, George W; Siegfried, Nandi

    2016-12-10

    The advent of highly active antiretroviral therapy (ART) has reduced the morbidity and mortality due to HIV infection. The World Health Organization (WHO) ART guidelines focus on three classes of antiretroviral drugs, namely nucleoside or nucleotide reverse transcriptase inhibitors (NRTI), non-nucleoside reverse transcriptase inhibitors (NNRTI) and protease inhibitors. Two of the most common medications given as first-line treatment are the NNRTIs, efavirenz (EFV) and nevirapine (NVP). It is unclear which NNRTI is more efficacious for initial therapy. This systematic review was first published in 2010. To determine which non-nucleoside reverse transcriptase inhibitor, either EFV or NVP, is more effective in suppressing viral load when given in combination with two nucleoside reverse transcriptase inhibitors as part of initial antiretroviral therapy for HIV infection in adults and children. We attempted to identify all relevant studies, regardless of language or publication status, in electronic databases and conference proceedings up to 12 August 2016. We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov to 12 August 2016. We searched LILACS (Latin American and Caribbean Health Sciences Literature) and the Web of Science from 1996 to 12 August 2016. We checked the National Library of Medicine (NLM) Gateway from 1996 to 2009, as it was no longer available after 2009. We included all randomized controlled trials (RCTs) that compared EFV to NVP in people with HIV without prior exposure to ART, irrespective of the dosage or NRTI's given in combination.The primary outcome of interest was virological success. Other primary outcomes included mortality, clinical progression to AIDS, severe adverse events, and discontinuation of therapy for any reason. Secondary outcomes were change in CD4 count, treatment failure

  16. Maternal HIV-1 disease progression 18-24 months postdelivery according to antiretroviral prophylaxis regimen (triple-antiretroviral prophylaxis during pregnancy and breastfeeding vs zidovudine/single-dose nevirapine prophylaxis): The Kesho Bora randomized controlled trial.

    Science.gov (United States)

    2012-08-01

    Antiretroviral (ARV) prophylaxis effectively reduces mother-to-child transmission of human immunodeficiency virus type 1 (HIV). However, it is unclear whether stopping ARVs after breastfeeding cessation affects maternal HIV disease progression. We assessed 18-24-month postpartum disease progression risk among women in a randomized trial assessing efficacy and safety of prophylactic maternal ARVs. From 2005 to 2008, HIV-infected pregnant women with CD4(+) counts of 200-500/mm(3) were randomized to receive either triple ARV (zidovudine, lamivudine, and lopinavir/ritonavir during pregnancy and breastfeeding) or AZT/sdNVP (zidovudine until delivery with single-dose nevirapine without postpartum prophylaxis). Maternal disease progression was defined as the combined endpoint of death, World Health Organization clinical stage 4 disease, or CD4(+) counts of prolonged triple ARV prophylaxis had no effect on HIV progression following cessation (compared with AZT/sdNVP). However, women on triple ARV prophylaxis had lower progression risk during the time on triple ARV. Given the high rate of progression among women with CD4(+) cells of <350/mm(3), ARVs should not be discontinued in this group. ISRCTN71468410.

  17. An Optimal Design for Placements of Tsunami Observing Systems Around the Nankai Trough, Japan

    Science.gov (United States)

    Mulia, I. E.; Gusman, A. R.; Satake, K.

    2017-12-01

    Presently, there are numerous tsunami observing systems deployed in several major tsunamigenic regions throughout the world. However, documentations on how and where to optimally place such measurement devices are limited. This study presents a methodological approach to select the best and fewest observation points for the purpose of tsunami source characterizations, particularly in the form of fault slip distributions. We apply the method to design a new tsunami observation network around the Nankai Trough, Japan. In brief, our method can be divided into two stages: initialization and optimization. The initialization stage aims to identify favorable locations of observation points, as well as to determine the initial number of observations. These points are generated based on extrema of an empirical orthogonal function (EOF) spatial modes derived from 11 hypothetical tsunami events in the region. In order to further improve the accuracy, we apply an optimization algorithm called a mesh adaptive direct search (MADS) to remove redundant measurements from the initially generated points by the first stage. A combinatorial search by the MADS will improve the accuracy and reduce the number of observations simultaneously. The EOF analysis of the hypothetical tsunamis using first 2 leading modes with 4 extrema on each mode results in 30 observation points spread along the trench. This is obtained after replacing some clustered points within the radius of 30 km with only one representative. Furthermore, the MADS optimization can improve the accuracy of the EOF-generated points by approximately 10-20% with fewer observations (23 points). Finally, we compare our result with the existing observation points (68 stations) in the region. The result shows that the optimized design with fewer number of observations can produce better source characterizations with approximately 20-60% improvement of accuracies at all the 11 hypothetical cases. It should be note, however, that our

  18. Flux and seasonality of planktonic foraminifera in the Xisha Trough, South China Sea

    Science.gov (United States)

    Xiang, R.; Chen, M.; Wang, D.; Chen, Z.; Yan, W.

    2013-12-01

    The modern correlation between planktonic foraminiferal community dynamics and environmental conditions may provide a basis for establishing paleoclimatic proxies. We studied planktic foraminiferal shell fluxes and assemblages in samples collected in a time-series sediment trap deployments in the Xisha Trough, South China Sea (SCS), from June 2009 to August 2011. The general flux shows a unimodal pattern, with high planktonic foraminiferal flux (900-1000 tests m-2 day-1) occurs during the period from late September/October to February, and low flux (200-300 tests m-2 day-1)during the rest period of the year. This flux pattern is contrast to the bimodal pattern of planktonic foraminiferal flux obtained from the central and southern SCS. Ten species, Globigeroides sacculifer, Globigerinoides ruber, Pulleniatina obliquiloculata, Neogloboquadrina dutertrei, Globigerina calida, Globigerinella aequilateralis, Globigerina bulloides, Globigerinita glutinata, Orbulina univera and Globorotalia menardii, contributed about 96% of the total flux in each year. Among them, the monsoonal driven seasonality is most prominent for P. obliquiloculata, N. dutertrei and G. bulloides, with more than 70% of their species-specific total fluxes (93% for G. bulloides) occur from late September/October to February. This suggests G. bulloides can be used as a winter proxy-species. On the contrary, Globigeroides conglobatus, mostly appeared during June to August. G. sacculifer, G. ruber and G. aequilateralis generally follow the trend of the total flux of planktonic foraminifer, with about 50-60% of their total fluxes occur from late September/October to February. We also compared the size distribution of the dominant foraminiferal species in the > 250 micrometer fraction and 250-154 micrometer fraction, we found that most shells of G. aequilateralis, O. univera and G. menardii, and G. conglobatus mainly occur in the >250 micrometer fraction, and about 40% of G. sacculifer, 35% of P

  19. Observations of Beach-Dune Interaction in Man-Made Trough Blowouts

    Science.gov (United States)

    Ruessink, G.; Arens, B.; Kuipers, M.; Van Onselen, E.; Donker, J.

    2016-02-01

    Dunes act as an indispensable natural safety barrier against marine flooding, are valuable natural environments, serve for the production of drinking water, and offer recreational opportunities. The safety function has dominated dune management in the Netherlands, as well as on other developed shores, for decades. Measures to minimize the seaward loss of foredune sand under storm wave attack have resulted in over-stabilized foredunes and, accordingly, have impoverished natural beauty and degraded biodiversity. Stabilized foredunes are nowadays increasingly reactivated by removing vegetation and by digging trenches that resemble natural trough blowouts as corridors for aeolian transport from the beach into the backdunes. Crucially, such measures see the beach-dune system as an integrated landscape, reconnecting the beach, foredune and backdunes through aeolian transport. This raises questions on how much sand is actually blown into the dunes, which factors affect this amount, and how effective the large-scale dune-restoration measures are. This contribution addresses the evolution of five trenches that were dug through the 20-m high foredune at the Dutch National Park Zuid-Kennemerland. The width of the trenches was 50 - 100 m, their cross-dune length was 60 - 100 m, and the heighest part of the valley floor was 9 m above mean sea level. Since their construction in the 2012/2013 winter the trenches have been surveyed approximately 3 times per year using airborne laser scanning or UAV photography, resulting in a multi-temporal data set of Digital Elevation Models (DEMs) with a 1x1 m resolution. Difference maps illustrate that the sidewalls of the trenches have steepened during the first two years after construction, but that their width and the height of the valley floor have remained largely unaltered. Landward of the trenches large sedimentation lobes have formed, which with time have grown both laterally and vertically. Locally, the lobe thickness now exceeds 5 m

  20. A study investigating the association of dermatological and infusion reactions to infliximab and infliximab trough levels.

    Science.gov (United States)

    Huang, Vivian; Dhami, Neil; Fedorak, Darryl; Prosser, Connie; Shalapay, Carol; Kroeker, Karen I; Halloran, Brendan P; Dieleman, Levinus A; Fedorak, Richard N

    2015-01-01

    Although infliximab is an effective therapy for inflammatory bowel disease (IBD), it is associated with dermatological events and infusion reactions. It is not known whether a relationship between these adverse events (AEs) and infliximab trough levels (ITLs) exists. To report the prevalence of infliximab-associated AEs in IBD patients receiving stable maintenance infliximab therapy, and to correlate ITLs with dermatological and infusion reactions to infliximab. Adult IBD patients receiving stable maintenance infliximab therapy were recruited from the University of Alberta Infusion Clinic (Edmonton, Alberta). ITLs were measured in blood samples collected before infusion, and the patients' records were reviewed for dermatological and infusion reactions to infliximab. One-quarter (18 of 71 [25.4%]) of patients experienced dermatological or infusion reactions to infliximab: nine (12.7%) dermatological events and nine (12.7%) infusion reactions. The median ITL was similar among patients with and without these AEs (7.2 μg⁄mL [interquartile range (IQR) 2.0 μg⁄mL to 13.3 μg⁄mL] versus 6.6 μg⁄mL [IQR 3.2 μg⁄mL to 12.7 μg⁄mL]; P=0.648). The median ITL of patients who experienced infusion reactions (2.0 μg⁄mL [IQR 0.1 μg⁄mL to 5.7 μg⁄mL]) was lower than that of patients who experienced no such AEs (6.6 μg⁄mL [IQR 3.2 μg⁄mL to 12.7 μg⁄mL]; P=0.008]) and lower than that of patients who experienced dermatological AEs (13.3 μg⁄mL [IQR 8.8 μg⁄mL to 17.4 μg⁄mL]; P<0.001). One-quarter of IBD outpatients receiving stable maintenance infliximab therapy experienced dermatological and infusion reactions. Low ITLs were correlated with infusion reactions, and normal or high ITLs with dermatological events.

  1. Geochemical Evidence for Recent Hydrothermal Alteration of Marine Sediments in Mid-Okinawa Trough, Southwest Japan

    Science.gov (United States)

    Tanaka, A.; Abe, G.; Yamaguchi, K. E.

    2014-12-01

    Recent studies have shown that submarine hydrothermal system supports diverse microbial life. Bio-essential metals supporting such microbial communities were released from basalts by high-temperature water-rock interaction in deeper part of the oceanic crust and carried by submarine fluid flow. Its total quantity in global hydrothermal settings has been estimated to be on the order of ~1019 g/yr, which is surprisingly on the same order of the total river flows (Urabe et al., 2011). Therefore, it is important to explore how submarine river system works, i.e., to understand mechanism and extent of elemental transport, which should lead to understanding of the roles of hydrothermal circulation in oceanic crust in controlling elemental budget in the global ocean and geochemical conditions to support deep hot biosphere.  We performed REE analysis of marine sediments influenced by submarine hydrothermal activity in Mid-Okinawa Trough. The sediment samples used in this study are from IODP site at Iheya North region and JADE site at Izena region. The samples show alternation between volcanic and clastic sediments. Hydrothermal fluids of this area contain elevated concentrations of volatile components such as H2, CO2, CH4, NH4+, and H2S, supporting diverse chemoautotrophic microbial community (Nakagawa et al., 2005). The purpose of this study is to examine the effect of hydrothermal activity on the REE signature of the sediments. Chondrite-normalized REE patterns of the samples show relative enrichment of light over heavy REEs, weak positive Ce anomalies, and variable degrees of negative Eu anomalies. The REE patterns suggest the sediments source was mainly basalt, suggesting insignificant input of continental materials. Negative Eu anomalies found in the IODP site become more pronounced with increasing depth, suggesting progressive increase of hydrothermal alteration where Eu was reductively dissolved into fluids by decomposition of feldspars. Contrary, at the JADE site

  2. A study investigating the association of dermatological and infusion reactions to infliximab and infliximab trough levels

    Science.gov (United States)

    Huang, Vivian Wai-Mei; Dhami, Neil; Fedorak, Darryl; Prosser, Connie; Shalapay, Carol; Kroeker, Karen Ivy; Halloran, Brendan Phillip; Dieleman, Levinus Albert; Fedorak, Richard Neil

    2015-01-01

    BACKGROUND: Although infliximab is an effective therapy for inflammatory bowel disease (IBD), it is associated with dermatological events and infusion reactions. It is not known whether a relationship between these adverse events (AEs) and infliximab trough levels (ITLs) exists. OBJECTIVES: To report the prevalence of infliximab-associated AEs in IBD patients receiving stable maintenance infliximab therapy, and to correlate ITLs with dermatological and infusion reactions to infliximab. METHODS: Adult IBD patients receiving stable maintenance infliximab therapy were recruited from the University of Alberta Infusion Clinic (Edmonton, Alberta). ITLs were measured in blood samples collected before infusion, and the patients’ records were reviewed for dermatological and infusion reactions to infliximab. RESULTS: One-quarter (18 of 71 [25.4%]) of patients experienced dermatological or infusion reactions to infliximab: nine (12.7%) dermatological events and nine (12.7%) infusion reactions. The median ITL was similar among patients with and without these AEs (7.2 μg/mL [interquartile range (IQR) 2.0 μg/mL to 13.3 μg/mL] versus 6.6 μg/mL [IQR 3.2 μg/mL to 12.7 μg/mL]; P=0.648). The median ITL of patients who experienced infusion reactions (2.0 μg/mL [IQR 0.1 μg/mL to 5.7 μg/mL]) was lower than that of patients who experienced no such AEs (6.6 μg/mL [IQR 3.2 μg/mL to 12.7 μg/mL]; P=0.008]) and lower than that of patients who experienced dermatological AEs (13.3 μg/mL [IQR 8.8 μg/mL to 17.4 μg/mL]; Pinfliximab therapy experienced dermatological and infusion reactions. Low ITLs were correlated with infusion reactions, and normal or high ITLs with dermatological events. PMID:25706572

  3. New insights into the origin of the felsic volcanic rocks in the middle Okinawa Trough

    Science.gov (United States)

    Zhang, Y.; Zeng, Z.

    2017-12-01

    The Okinawa Trough (OT) is a nascent back arc basin developing in the eastern margin of the Eurasian Plate. The middle segment of the OT (MOT) is featured by bimodal volcanism with dominant basalts and rhyolites and scarce intermediate volcanic rocks. The MOT rhyolites are divided into two types: type 1 rhyolites have lower heavy rare earth element (HREE) contents while type 2 rhyolites feature higher HREE contents and have slightly more enriched Sr-Nd isotopic ratios than type 1 rhyolites. The MOT rhyolites share similar Sr-Nd isotopic compositions with the MOT basalts and thus they have been typically considered as products of crystallization differentiation of basaltic magma. However, the evidence is insufficient. This paper compared chemical trends of volcanic rocks from the MOT with fractional crystallization simulation models and experimental results and utilized trace element modeling (e.g., Th vs. Rb, Rb/Nd vs. Rb, Rb vs. Rb/V, 1/V vs. Rb/V) combined with quantitative calculations to re-examine the magmatic processes in generating the rhyolites. The trace element discriminant models show that the andesites indicate a fractional crystallization trend, type 1 rhyolites present a partial melting trend, and type 2 rhyolites define a mixing trend. Further, by establishing Rayleigh fractionation and batch melting models, we found that the andesites originated by fractional crystallization of basaltic magma while the rhyolites were the products of remelting of andesites. Type 2 rhyolites have higher Dy/Yb and Nb/Ta ratios than type 1 rhyolites, implying that the former might be influenced by a greater contribution of amphibole. Quantitative models suggest that type 1 rhyolites could have formed via the remelting of andesites when amphiboles remain in the source, whereas type 2 rhyolites could have formed without residual amphiboles. Quasi-linear correlations between some major oxides, trace element ratios and Sr-Nd isotopic ratios for type 2 rhyolites suggest that

  4. Application of MASW method in studies on changes of soil elastic parameters over subsidence trough development during longwall exploitation

    Science.gov (United States)

    Mendecki, Maciej; Jochymczyk, Krzysztof

    2015-04-01

    The MASW method interpretation was applied to analyze 37 measurements which had been carried out to investigate spatial and temporal changes of elastic parameters in subsurface layers during extracting the coal bed. The seismic measurements were performed using the Terraloc apparatus containing 12 channels connected with 10 Hz geophones. 5 survey profiles were formed into a rosette with arms arranged relative about 45 degrees to each other. The research area was located in the Main Anticline, Upper Silesian Coal Basin, Southern Poland. The rosette was placed over the 201 longwall belonged to "Katowice - Kleofas" Coal Mine. Shallow geological structure consisted of subsurface soft layer (several meters) covered consolidated Carboniferous complex. Data interpretation were executed in winMASW software using the genetic algorithms to invert observed Rayleigh dispersion curve into S-wave velocity vertical profiles. In addition, the inversion allowed to determine parameters such as: density, thickness, shear modulus. The seismic study were carried out during total exploitation of the coal bed and for next 8 month after completion of mining works. Longer seismic observations than the mining works were due to a subsidence trough development over coal bed because the longwall face passage and subsidence trough development were shifted in time and it reached about 3 month. This time was needed to appear the subsidence trough on surface what was confirmed by leveling measurements. The longwall face had passed beneath the rosette in December, 1999 and in March, 2000 a sharp velocity drop on each profile was noticed. Next, a sudden velocity increase appeared in subsurface layer after the velocity drop. The changes of density and shear modulus was also remarked during the same period. At the beginning the sudden drop in velocity and other elastic parameters was associated with tension appeared on borders of subsidence trough. Then the geophysical profiles were in the compressive

  5. Geochemical features of trace and rare earth elements of pumice in middle Okinawa Trough and its indication of magmatic process

    Science.gov (United States)

    Zhai, Shikui; Guo, Kun; Zong, Tong; Yu, Zenghui; Wang, Shujie; Cai, Zongwei; Zhang, Xia

    2017-04-01

    Pumice, the most widely distributed volcanic rock in Okinawa Trough, is loose and porous. Since its formation, it has definitely suffered from the denudation of the sea to different degrees. In order to truly reveal the geochemical features of pumice, we choose the method of mineral separation. Firstly, the phenocryst is separated from glass. Then the phenocryst is divided into light and heavy mineral compositions. By ICP-MS (inductively coupled plasma mass spectrometry) analytical technology, the contents of trace and rare earth elements in the whole pumice, the glass and the heavy and light mineral compositions are determined respectively. By researching the elemental geochemical features, the magma dynamic processes are found. It shows that the initial magma for the pumice in Okinawa Trough came from the depleted mantle, from which the N-MORB (normal type of mid-ocean ridge basalt) is formed, homologous with the local basalts. But they are formed in different periods of magma crystal fractionation. Featured with sufficient crystal fractionation for pumice, it is found that the earlier crystallizing minerals are olivine, plagioclase and pyroxene. The pumice magma, formed from the depleted mantle, was mixed with additional subduction-related materials (components), and contaminated with the mass from upper crust when it rose up into the crust. As the Okinawa Trough is a back-arc basin in its early back-arc spreading stage, its magmatism has a series of its own unique characteristics, different from not only the mid-ocean ridge expansion, but also the mature back-arc basin.

  6. Investigation of severe slugging under flow conditions of a parabolic trough power plant with direct steam generation

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Alexander [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Div. Reactor Safety

    2016-07-01

    The DISS test facility at the Plataforma Solar de Almeria, Spain, produces high pressure steam directly within the parabolic trough collectors. Two collectors are connected with a U-shaped connection pipe which can suffer under the flow phenomenon of severe slugging at low mass flow operation. The objective is to investigate numerically the flow situations with ATHLET and state the relevance of severe slugging in the installed U-shaped pipes. The simulation results reveal that normal operation conditions are uncritical and no severe slugging can be expected.

  7. Tectonic and volcanic history of Rhea as inferred from studies of scarps, ridges, troughs, and other lineaments

    International Nuclear Information System (INIS)

    Thomas, P.G.

    1988-01-01

    The 13 geomorphic feature types presently defined through the analysis of landforms on Rhea are with only one exception interpretable as of tectonic or volcanic-tectonic origin. The troughs, grabens, grooves, pit chains, scarps, and other lineaments are purely extensional in nature, while the ridges are volcanic features formed in an extensional stress field; this extension was followed by a global compression era generating megaridges and megascarps. The extensional landforms seem to form a global grid pattern that is directionally similar to the theoretically projected pattern of a tidally distorted planet. 17 references

  8. Higher tacrolimus trough levels on days 2-5 post-renal transplant are associated with reduced rates of acute rejection.

    LENUS (Irish Health Repository)

    O'Seaghdha, C M

    2011-04-06

    We analyzed the association between whole-blood trough tacrolimus (TAC) levels in the first days post-kidney transplant and acute cellular rejection (ACR) rates. Four hundred and sixty-four consecutive, deceased-donor kidney transplant recipients were included. All were treated with a combination of TAC, mycophenolate mofetil and prednisolone. Patients were analyzed in four groups based on quartiles of the mean TAC on days 2 and 5 post-transplant: Group 1: median TAC 11 ng\\/mL (n = 122, range 2-13.5 ng\\/mL), Group 2: median 17 ng\\/mL (n = 123, range 14-20 ng\\/mL), Group 3: median 24 ng\\/mL (n = 108, range 20.5-27 ng\\/mL) and Group 4: median 33.5 ng\\/mL (n = 116, range 27.5-77.5 ng\\/mL). A graded reduction in the rates of ACR was observed for each incremental days 2-5 TAC. The one-yr ACR rate was 24.03% (95% CI 17.26-32.88), 22.20% (95% CI 15.78-30.70), 13.41% (95% CI 8.15-21.63) and 8.69% (95% CI 4.77-15.55) for Groups 1-4, respectively (p = 0.003). This study suggests that higher early TACs are associated with reduced rates of ACR at one yr.

  9. Wave and plasma measurements and GPS diagnostics of the main ionospheric trough as a hybrid method used for Space Weather purposes

    Directory of Open Access Journals (Sweden)

    H. Rothkaehl

    2008-02-01

    Full Text Available The region of the main ionospheric trough is a unique region of the ionosphere, where different types of waves and instabilities can be generated. This region of the ionosphere acts like a lens, focusing a variety of indicators from the equator of plasmapause and local ionospheric plasma. This paper reports the results of monitoring the mid-latitude trough structure, dynamics and wave activity. For these purposes, the data gathered by the currently-operating DEMETER satellite and past diagnostics located on IK-19, Apex, and MAGION-3 spacecraft, as well as TEC measurements were used. A global-time varying picture of the ionospheric trough was reconstructed using the sequence of wave spectra registered and plasma measurements in the top-side ionosphere. The authors present the wave activity from ULF frequency band to the HF frequency detected inside the trough region and discuss its properties during geomagnetic disturbances. It is thought that broadband emissions are correlated with low frequency radiation, which is excited by the wave-particle interaction in the equatorial plasmapause and moves to the ionosphere along the geomagnetic field line. In the ionosphere, the suprathermal electrons can interact with these electrostatic waves and excite electron acoustic waves or HF longitudinal plasma waves.

    Furthermore, the electron density trough can provide useful data on the magnetosphere ionosphere dynamics and morphology and, in consequence, can be used for Space Weather purposes.

  10. Wave and plasma measurements and GPS diagnostics of the main ionospheric trough as a hybrid method used for Space Weather purposes

    Directory of Open Access Journals (Sweden)

    H. Rothkaehl

    2008-02-01

    Full Text Available The region of the main ionospheric trough is a unique region of the ionosphere, where different types of waves and instabilities can be generated. This region of the ionosphere acts like a lens, focusing a variety of indicators from the equator of plasmapause and local ionospheric plasma. This paper reports the results of monitoring the mid-latitude trough structure, dynamics and wave activity. For these purposes, the data gathered by the currently-operating DEMETER satellite and past diagnostics located on IK-19, Apex, and MAGION-3 spacecraft, as well as TEC measurements were used. A global-time varying picture of the ionospheric trough was reconstructed using the sequence of wave spectra registered and plasma measurements in the top-side ionosphere. The authors present the wave activity from ULF frequency band to the HF frequency detected inside the trough region and discuss its properties during geomagnetic disturbances. It is thought that broadband emissions are correlated with low frequency radiation, which is excited by the wave-particle interaction in the equatorial plasmapause and moves to the ionosphere along the geomagnetic field line. In the ionosphere, the suprathermal electrons can interact with these electrostatic waves and excite electron acoustic waves or HF longitudinal plasma waves. Furthermore, the electron density trough can provide useful data on the magnetosphere ionosphere dynamics and morphology and, in consequence, can be used for Space Weather purposes.

  11. Therapeutic drug monitoring of voriconazole helps to decrease the percentage of patients with off-target trough serum levels.

    Science.gov (United States)

    Guinea, Jesús; Escribano, Pilar; Marcos-Zambrano, Laura Judith; Peláez, Teresa; Kestler, Marta; Muñoz, Patricia; Vena, Antonio; López-Fabal, Fátima; Bouza, Emilio

    2016-05-01

    We monitored trough voriconazole serum concentrations from 107 patients (n = 258 samples) at 6 hospitals in Madrid. Most of the patients were male (67%) and had the following underlying conditions: hematological cancer (42%), solid organ transplantation (15%), chronic obstructive pulmonary disease (14%), human immunodeficiency virus infection (8.4%), solid cancer (5.6%), and other (29%). The indication for voriconazole administration was aspergillosis treatment (74.6%) and prophylaxis (14%). The main reasons for voriconazole trough drug monitoring were initiation of treatment/prophylaxis (33%), patient monitoring (47%), and suspected toxicity (3.5%). Levels (μg/ml) were subtherapeutic (5.5; 10.5%). The samples percentage with on-target levels was significantly lower for the first sample than for subsequent samples (62.6% vs. 77.5%). "Subsequent samples," "admission in nonpediatric wards," "voriconazole used for treatment of invasive aspergillosis," and "use of proton pump inhibitors" were predictors of voriconazole therapeutic levels (≥1 μg/ml). © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Different effects of lansoprazole and rabeprazole on the plasma voriconazole trough levels in allogeneic hematopoietic cell transplant recipients.

    Science.gov (United States)

    Yasu, Takeo; Konuma, Takaaki; Kato, Seiko; Kurokawa, Yosuke; Takahashi, Satoshi; Tojo, Arinobu

    2016-10-01

    Voriconazole (VRC) is widely used as prophylaxis and in the treatment of invasive fungal disease (IFD) after allogeneic hematopoietic cell transplantation (HCT). We retrospectively examined the results of VRC therapeutic drug monitoring (TDM) in allogeneic HCT recipients. A total of 474 samples were obtained from 59 adult patients who received VRC during the first 100 days following HCT between 2009 and 2014 in our institute. Seventeen patients received VRC for prophylaxis of IFD, and 42 received VRC for the empirical or preemptive therapy for IFD. A total of 299 samples (63 %) were obtained during the administration of the intravenous form of VRC. The median VRC daily dose based on the actual body weight was 6.68 mg/kg/day (range, 1.92-10.41 mg/kg/day). The median VRC trough level was 0.99 mg/l (range, lansoprazole as compared to rabeprazole (P lansoprazole and rabeprazole have different effects on the plasma VRC trough levels in the allogeneic HCT recipients.

  13. Distribution of bacterioplankton with active metabolism in waters of the St. Anna Trough, Kara Sea, in autumn 2011

    Science.gov (United States)

    Mosharova, I. V.; Mosharov, S. A.; Ilinskiy, V. V.

    2017-01-01

    The distribution of bacterioplankton with active electron transport chains, as well as bacteria with intact cell membranes, was investigated for the first time in the region of St. Anna Trough in the Kara Sea. The average number of bacteria with active electron transport chains in the waters of the St. Anna Trough was 15.55 × 103 cells mL-1 (the limits of variation were 1.06-92.17 × 103 cells mL-1). The average number of bacteria with intact membranes was 33.46 × 103 cells mL-1 (the limits of variation were 6.78 to 103.18 × 103 cells mL-1). Almost all bacterioplankton microorganisms in the studied area were potentially viable, and the average share of bacteria with intact membranes was 92.1% of the total number of bacterioplankton (TNB) (the limits of variation were 76.2 to 98.4%). The share of bacteria with active metabolisms was 38.2% of the TNB (the limits of variation were 5.6-93.4%). The shares of the bacteria with active metabolisms were maximum in areas with the most stable environmental conditions (on the shelf and in deep water), whereas on the slope, where the gradients of water temperature and salinity were maximum, these values were lower.

  14. Available Energy and Cumulative Frequency Curves for Parabolic Trough Concentrators with Alignment North–South, in the Northwest of Mexico

    Directory of Open Access Journals (Sweden)

    Álvaro Lentz–Herrea

    2009-04-01

    Full Text Available The Northwest of Mexico is a well known region with the highest ambient temperatures along the summer and the highest levels of irradiance, which make it feasible to install solar field concentrators. This work provides beam irradiance data that can be used to design a solar north–south parabolic trough system. The variation between the value of beam solar irradiance estimated by a pyranometer and the direct irradiance received by the aperture area of a parabolic trough concentrator (PTC is well–known as cosθ. This variation was evaluated every day of the year, obtaining values of average irradiance for Cerro Prieto (CP lat. 32°39', long. 115° 21', and San Luis Rio Colorado (SLR lat. 32°30', long. 114°46', with which they were elaborated the available energy and cumulative frequency curves (CFC. These are useful to know the number of hours of field solar concentrators which can operate at different levels of energy, as well as the steam production of a solar–geothermal hybrid system to produce electricity.

  15. Annual measured and simulated thermal performance analysis of a hybrid solar district heating plant with flat plate collectors and parabolic trough collectors in series

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2017-01-01

    in large solar heating plants for a district heating network, a hybrid solar collector field with 5960 m2 flat plate collectors and 4039 m2 parabolic trough collectors in series was constructed in Taars, Denmark. The design principle is that the flat plate collectors preheat the return water from...... the district heating network to about 70 °C and then the parabolic trough collectors would heat the preheated water to the required supply temperature of the district heating network. Annual measured and simulated thermal performances of both the parabolic trough collector field and the flat plate collector...... field are presented in this paper. The thermal performance of both collector fields with weather data of a Design Reference Year was simulated to have a whole understanding of the application of both collectors under Danish climate conditions as well. These results not only can provide a design basis...

  16. Decadal Modulation of Repeating Slow Slip Event Activity in the Southwestern Ryukyu Arc Possibly Driven by Rifting Episodes at the Okinawa Trough

    Science.gov (United States)

    Tu, Yoko; Heki, Kosuke

    2017-09-01

    We studied 38 slow slip events (SSEs) in 1997-2016 beneath the Iriomote Island, southwestern Ryukyu Arc, Japan, using continuous Global Navigation Satellite Systems data. These SSEs occur biannually on the same fault patch at a depth of 30 km on the subducting Philippine Sea Plate slab with average moment magnitudes (Mw) of 6.6. Here we show that the slip accumulation rate (cumulative slip/lapse time) of these SSEs fluctuated over a decadal time scale. The rate increased twice around 2002 and 2013 concurrently with earthquake swarms in the Okinawa Trough. This suggests that episodic activations of the back-arc spreading at the Okinawa Trough caused extra southward movement of the block south of the trough and accelerated convergence at the Ryukyu Trench.

  17. Healthcare-associated Staphylococcus aureus bacteremia in children: Evidence for reverse vancomycin creep and impact of vancomycin trough levels on outcome

    Science.gov (United States)

    McNeil, J Chase; Kok, Eric Y; Forbes, Andrea; Lamberth, Linda; Hulten, Kristina G; Vallejo, Jesus G; Mason, Edward O; Kaplan, Sheldon L

    2015-01-01

    Introduction Elevated vancomycin MICs in S. aureus have been associated with worse clinical outcomes in adults. For invasive MRSA infections in adults, the IDSA recommends targeting vancomycin serum trough concentrations between 15–20 μg/ml. We evaluated trends in vancomycin MICs from healthcare-associated S. aureus bacteremia isolates in children in addition to correlating vancomycin serum trough levels with clinical outcomes. Methods Patients and isolates were identified from a prospective S. aureus surveillance study at Texas Children's Hospital (TCH). Healthcare-associated S. aureus bacteremia isolates from 2003–2013 were selected. Vancomycin MICs by E-test were determined and medical records were reviewed. Acute kidney injury (AKI) was defined as doubling of the baseline serum creatinine. Results 341 isolates met inclusion criteria. We observed a reverse vancomycin creep among MRSA isolates in the study period with a decline in the proportion of isolates with vancomycin MIC ≥ 2 μg/ml (from 32.7% to 5.6%, pvancomycin troughs performed, there was no difference in duration of bacteremia or fever with vancomycin trough >15 μg/ml vs. vancomycin trough > 15 μg/ml was, however, an independent risk factor for AKI. Conclusions Vancomycin MICs are shifting among healthcare-associated S. aureus bacteremia isolates with significant differences between MRSA and MSSA at TCH. Higher vancomycin troughs did not improve outcomes in pediatric healthcare-associated S. aureus bacteremia but were associated with increased nephrotoxicity. Further studies are needed to better understand optimal management of children with S. aureus bacteremia. PMID:26646549

  18. Clinical relevance and inter-test reliability of anti-infliximab antibodies and infliximab trough levels in patients with inflammatory bowel disease.

    Science.gov (United States)

    Guiotto, Cristina; Daperno, Marco; Frigerio, Francesco; Vizzini, Margherita; Cerruti, Roberta; Ercole, Elena; Cosimato, Maurizio; Lavagna, Alessandro; Germano, Laura; Migliardi, Marco; Rocca, Rodolfo

    2016-02-01

    Treatment with infliximab is a common option for inflammatory bowel disease (IBD) patients. Therapeutic drug monitoring could improve treatment management. To test inter-test reliability of two commercially available diagnostic kits for infliximab trough levels and infliximab antibodies, and their association with treatment outcomes. 86 IBD outpatients on infliximab maintenance treatment were enrolled in a prospective cross-sectional study, 115 samples were available for inter-test reliability. Inter-test agreement was good both for trough levels (concordance correlation coefficient 0.78, weighted κ 0.60, Sperman's ρ 0.937) and for infliximab antibodies (weighted κ 0.79) measurement, when comparing Promonitor and ImmunDiagnostik kits. According to manufacturers' cut-off values, trough levels were classified as undetectable (17%), low (21%) or in range (63%). The only significant associations were: mucosal healing (p=0.026; OR 6.50), infliximab antibody status (p=0.0015; OR 0.031) and adverse events (p=0.009; OR 0.115). Higher trough levels were observed among patients on concomitant steroid/immunosuppressive therapy and among patients with dose-intensification. Infliximab antibodies were significantly associated to treatment-related adverse events (p=0.0003, OR 30.42), and to lower trough levels, but not to other clinical variables. The two tests performed equally well. Infliximab antibodies were associated to adverse events, while trough levels were not associated to treatment outcomes. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  19. Shallow Crustal Structure in the Northern Salton Trough, California: Insights from a Detailed 3-D Velocity Model

    Science.gov (United States)

    Ajala, R.; Persaud, P.; Stock, J. M.; Fuis, G. S.; Hole, J. A.; Goldman, M.; Scheirer, D. S.

    2017-12-01

    The Coachella Valley is the northern extent of the Gulf of California-Salton Trough. It contains the southernmost segment of the San Andreas Fault (SAF) for which a magnitude 7.8 earthquake rupture was modeled to help produce earthquake planning scenarios. However, discrepancies in ground motion and travel-time estimates from the current Southern California Earthquake Center (SCEC) velocity model of the Salton Trough highlight inaccuracies in its shallow velocity structure. An improved 3-D velocity model that better defines the shallow basin structure and enables the more accurate location of earthquakes and identification of faults is therefore essential for seismic hazard studies in this area. We used recordings of 126 explosive shots from the 2011 Salton Seismic Imaging Project (SSIP) to SSIP receivers and Southern California Seismic Network (SCSN) stations. A set of 48,105 P-wave travel time picks constituted the highest-quality input to a 3-D tomographic velocity inversion. To improve the ray coverage, we added network-determined first arrivals at SCSN stations from 39,998 recently relocated local earthquakes, selected to a maximum focal depth of 10 km, to develop a detailed 3-D P-wave velocity model for the Coachella Valley with 1-km grid spacing. Our velocity model shows good resolution ( 50 rays/cubic km) down to a minimum depth of 7 km. Depth slices from the velocity model reveal several interesting features. At shallow depths ( 3 km), we observe an elongated trough of low velocity, attributed to sediments, located subparallel to and a few km SW of the SAF, and a general velocity structure that mimics the surface geology of the area. The persistence of the low-velocity sediments to 5-km depth just north of the Salton Sea suggests that the underlying basement surface, shallower to the NW, dips SE, consistent with interpretation from gravity studies (Langenheim et al., 2005). On the western side of the Coachella Valley, we detect depth-restricted regions of

  20. Simulation of thermal fluid dynamics in parabolic trough receiver tubes with direct steam generation using the computer code ATHLET

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Alexander; Merk, Bruno [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany); Hirsch, Tobias; Pitz-Paal, Robert [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Stuttgart (Germany). Inst. fuer Solarforschung

    2014-06-15

    In the present feasibility study the system code ATHLET, which originates from nuclear engineering, is applied to a parabolic trough test facility. A model of the DISS (DIrect Solar Steam) test facility at Plataforma Solar de Almeria in Spain is assembled and the results of the simulations are compared to measured data and the simulation results of the Modelica library 'DissDyn'. A profound comparison between ATHLET Mod 3.0 Cycle A and the 'DissDyn' library reveals the capabilities of these codes. The calculated mass and energy balance in the ATHLET simulations are in good agreement with the results of the measurements and confirm the applicability for thermodynamic simulations of DSG processes in principle. Supplementary, the capabilities of the 6-equation model with transient momentum balances in ATHLET are used to study the slip between liquid and gas phases and to investigate pressure wave oscillations after a sudden valve closure. (orig.)

  1. Energetic and exergetic analysis of Rankine cycles for solar power plants with parabolic trough and thermal storage

    Directory of Open Access Journals (Sweden)

    Cenuşă Victor-Eduard

    2016-01-01

    Full Text Available The paper analyzes the “secondary” circuit (for thermodynamic conversion of a Concentrated Solar Power (CSP plant with thermodynamic cycle, whose mirrors field supplies a thermal power, averaged over a sunny day, of about 100 MW heat. We study the case of parabolic trough solar collector using silicone oil in the “primary” circuit, which limits the peak temperature below 400 °C. The “primary” circuit uses thermal storage, allowing a delay between the power generation in rapport with the solar energy capture. We choose a water-steam cycle, type Hirn. For increasing its efficiency, it has regenerative feed water preheating and steam reheating. We compared, energetic and exergetic, two types of cycles, using a numerical model with iterative structure, developed by the authors. The results showed that the simplified design achieves practically the same thermodynamic performances with the advanced one.

  2. Sensitivity analysis in the test of a parabolic trough solar collector (PTSC) with flat null-screens

    Science.gov (United States)

    Campos-García, Manuel; Huerta-Carranza, Oliver; Díaz-Uribe, José Rufino; Moreno-Oliva, Víctor Iván.; Santiago-Alvarado, Agustín.; Peña-Conzueloa, Andrés.

    2016-09-01

    In this work we proposed a flat null-screen method to test parabolic trough solar collectors (PTSC). The null-screen testing method measures the slope of the test surface and by a numerical integration procedure the shape of the test surface can be obtained. In this work, we show that the test can be sensitive to small surface deformations, such as those caused by sinusoidal deformations with different amplitudes and spatial periods introduced on the PTSC surface. These calculations also show that the attainable theoretical slope accuracy in the rms sense is about 0.34 mrad. This value was obtained under the assumption that is possible to achieve a 1-pixel resolution on the measurement of the position departures of the centroids of the targets of the null-screen.

  3. Low infliximab serum trough levels and anti-infliximab antibodies are prevalent in rheumatoid arthritis patients treated with infliximab in daily clinical practice: results of an observational cohort study

    NARCIS (Netherlands)

    van der Maas, A.; van den Bemt, B.J.; Wolbink, G.; Hoogen, F.H.J. van den; van Riel, P.L.; Broeder, A. den

    2012-01-01

    ABSTRACT: BACKGROUND: To get insight in the prevalence of high, or low/no serum infliximab trough levels in patients with low disease activity and if serum trough levels are stable and reliable longitudinally we conducted a prospective cohort study METHODS: In a longitudinal, observational cohort of

  4. Amplitude versus offset analysis to marine seismic data acquired in Nankai Trough, offshore Japan where methane hydrate exists

    Science.gov (United States)

    Hato, M.; Inamori, T.; Matsuoka, T.; Shimizu, S.

    2003-04-01

    Occurrence of methane hydrates in the Nankai Trough, located off the south-eastern coast of Japan, was confirmed by the exploratory test well drilling conducted by Japan’s Ministry of International Trade and Industry in 1999. Confirmation of methane hydrate has given so big impact to the Japan's future energy strategy and scientific and technological interest was derived from the information of the coring and logging results at the well. Following the above results, Japan National Oil Corporation (JNOC) launched the national project, named as MH21, for establishing the technology of methane hydrate exploration and related technologies such as production and development. As one of the research project for evaluating the total amount of the methane hydrate, Amplitude versus Offset (AVO) was applied to the seismic data acquired in the Nankai Trough area. The main purpose of the AVO application is to evaluate the validity of delineation of methane hydrate-bearing zones. Since methane hydrate is thought to accompany with free-gas in general just below the methane hydrate-bearing zones, the AVO has a possibility of describing the presence of free-gas. The free-gas is thought to be located just below the base of methane hydrate stability zone which is characterized by the Bottom Simulating Reflectors (BSRs) on the seismic section. In this sense, AVO technology, which was developed as gas delineation tools, can be utilized for methane hydrate exploration. The result of AVO analysis clearly shows gas-related anomaly below the BSRs. Appearance of the AVO anomaly has so wide variety. Some of the anomalies might not correspond to the free-gas existence, however, some of them may show free-gas. We are now going to develop methodology to clearly discriminate free-gas from non-gas zone by integrating various types of seismic methods such as seismic inversion and seismic attribute analysis.

  5. Microplastic pollution identified in deep-sea water and ingested by benthic invertebrates in the Rockall Trough, North Atlantic Ocean.

    Science.gov (United States)

    Courtene-Jones, Winnie; Quinn, Brian; Gary, Stefan F; Mogg, Andrew O M; Narayanaswamy, Bhavani E

    2017-12-01

    Microplastics are widespread in the natural environment and present numerous ecological threats. While the ultimate fate of marine microplastics are not well known, it is hypothesized that the deep sea is the final sink for this anthropogenic contaminant. This study provides a quantification and characterisation of microplastic pollution ingested by benthic macroinvertebrates with different feeding modes (Ophiomusium lymani, Hymenaster pellucidus and Colus jeffreysianus) and in adjacent deep water > 2200 m, in the Rockall Trough, Northeast Atlantic Ocean. Despite the remote location, microplastic fibres were identified in deep-sea water at a concentration of 70.8 particles m -3 , comparable to that in surface waters. Of the invertebrates examined (n = 66), 48% ingested microplastics with quantities enumerated comparable to coastal species. The number of ingested microplastics differed significantly between species and generalized linear modelling identified that the number of microplastics ingested for a given tissue mass was related to species and not organism feeding mode or the length or overall weight of the individual. Deep-sea microplastics were visually highly degraded with surface areas more than double that of pristine particles. The identification of synthetic polymers with densities greater and less than seawater along with comparable quantities to the upper ocean indicates processes of vertical re-distribution. This study presents the first snapshot of deep ocean microplastics and the quantification of microplastic pollution in the Rockall Trough. Additional sampling throughout the deep-sea is required to assess levels of microplastic pollution, vertical transportation and sequestration, which have the potential to impact the largest global ecosystem. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Effect of infliximab dose increase in rheumatoid arthritis at different trough concentrations: a cohort study in clinical practice conditions

    Directory of Open Access Journals (Sweden)

    Chamaida ePlasencia

    2015-10-01

    Full Text Available BackgroundEvidence supporting treatment intensification in rheumatoid arthritis is limited and controversial. We explored outcomes of infliximab dose increases and accounted for pre-existing trough levels in patients with active rheumatoid arthritis (RA.MethodsThis study was a retrospective study of 42 RA patients who received increased infliximab following an insufficient response (DAS28 > 3.2. Serum concentrations of infliximab and antibodies to infliximab (ATI and DAS28 and EULAR clinical response parameters were recorded for one year. Analyses were performed in three patient groups that were defined by infliximab serum concentration prior to treatment enhancement: No detectable, Low (< 1.1 µg/mL or High (≥ 1.1 µg/mL drug levels. Results No circulating infliximab was detected in 20 patients (47.6 %, but 13 (30.9 % and 9 (21.4 % patients exhibited Low and High levels, respectively. ATI were only detected in patients with No detectable drug levels because the drug interferes with ELISA. DAS28 disease activity globally showed a modest improvement after dose escalation, but this improvement did not persist after 6 and 12 months. Infliximab serum levels increased significantly in the High group (p=0.016, but no increase was achieved in the Low and No detectable groups. The three study groups exhibited similar disease activity over time, and no improvement was observed in the non-responder EULAR rates. ConclusionsThese results suggest that the efficacy of an infliximab dose increase is limited, and the response is independent of the infliximab trough serum concentration that is achieved prior to escalation.

  7. Biogenic Methane Generation Potential in the Eastern Nankai Trough, Japan: Effect of Reaction Temperature and Total Organic Carbon

    Science.gov (United States)

    Aung, T. T.; Fujii, T.; Amo, M.; Suzuki, K.

    2017-12-01

    Understanding potential of methane flux from the Pleistocene fore-arc basin filled turbiditic sedimentary formation along the eastern Nankai Trough is important in the quantitative assessment of gas hydrate resources. We considered generated methane could exist in sedimentary basin in the forms of three major components, and those are methane in methane hydrate, free gas and methane dissolved in water. Generation of biomethane strongly depends on microbe activity and microbes in turn survive in diverse range of temperature, salinity and pH. This study aims to understand effect of reaction temperature and total organic carbon on generation of biomethane and its components. Biomarker analysis and cultural experiment results of the core samples from the eastern Nankai Trough reveal that methane generation rate gets peak at various temperature ranging12.5°to 35°. Simulation study of biomethane generation was made using commercial basin scale simulator, PetroMod, with different reaction temperature and total organic carbon to predict how these effect on generation of biomethane. Reaction model is set by Gaussian distribution with constant hydrogen index and standard deviation of 1. Series of simulation cases with peak reaction temperature ranging 12.5°to 35° and total organic carbon of 0.6% to 3% were conducted and analyzed. Simulation results show that linear decrease in generation potential while increasing reaction temperature. But decreasing amount becomes larger in the model with higher total organic carbon. At higher reaction temperatures, >30°, extremely low generation potential was found. This is due to the fact that the source formation modeled is less than 1 km in thickness and most of formation do not reach temperature more than 30°. In terms of the components, methane in methane hydrate and free methane increase with increasing TOC. Drastic increase in free methane was observed in the model with 3% of TOC. Methane amount dissolved in water shows almost

  8. Changes in serum trough levels of infliximab during treatment intensification but not in anti-infliximab antibody detection are associated with clinical outcomes after therapeutic failure in Crohn's disease

    DEFF Research Database (Denmark)

    Steenholdt, Casper; Bendtzen, Klaus; Brynskov, Jørn

    2015-01-01

    BACKGROUND AND AIMS: Intensification of the infliximab (IFX) regimen is recommended if the treatment effect is inadequate. However, the rationale for this is not well defined as the underlying mechanisms vary. The aim of this study was to explore the association between changes in serum IFX...... and anti-IFX antibodies (Abs) after IFX intensification and clinical outcomes. METHODS: We performed a post hoc analysis of a randomized clinical trial including 42 Crohn's disease patients with IFX treatment failure, all treated with an intensified IFX regimen (5mg/kg every 4 week) for 12 weeks. Trough...... serum IFX and anti-IFX Ab concentrations were measured by a homogeneous mobility shift binding assay (HMSA) and a functional cell-based reporter gene assay (RGA) at treatment failure and the end of the trial. RESULTS: Twenty-one patients (50%) regained clinical response on the intensified IFX regimen...

  9. A Novel Volume CT With X-Ray on a Trough-Like Surface and Point Detectors on Circle-Plus-Arc Curve

    National Research Council Canada - National Science Library

    Xu, H

    2001-01-01

    A novel imaging mode of cone-beam volume CT is proposed in this paper. It adopts a raster scanning x-ray source on a trough-like surface, and a group of point detectors distributing on a large circle plus an orthogonal arc...

  10. The relationship between the vortical structure and the wall shear stress in a blind trough cavity subject to a jet impingement

    Czech Academy of Sciences Publication Activity Database

    Knob, Martin; Uruba, Václav

    2008-01-01

    Roč. 8, č. 1 (2008), s. 10621-10622 ISSN 1617-7061 R&D Projects: GA ČR GA101/08/1112 Institutional research plan: CEZ:AV0Z20760514 Keywords : blind trough cavity * jet impingement * dynamics * Time Resolved PIV Subject RIV: BK - Fluid Dynamics http://www3.interscience.wiley.com/societies/gamm/

  11. Novel archaeal macrocyclic diether core membrane lipids in a methane-derived carbonate crust from a mud volcano in the Sorokin Trough, NE Black Sea

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Stadnitskaia, A.N.; Baas, M.K.; Ivanov, M.K.; Weering, T.C.E. van

    2003-01-01

    A methane-derived carbonate crust was collected from the recently discovered NIOZ mud volcano in the Sorokin Trough, NE Black Sea during the 11th Training-through-Research cruise of the R/V Professor Logachev. Among several specific bacterial and archaeal membrane lipids present in this crust, two

  12. C2 (2-h) levels are not superior to trough levels as estimates of the area under the curve in tacrolimus-treated renal-transplant patients

    DEFF Research Database (Denmark)

    Jørgensen, Kaj; Povlsen, Johan; Madsen, Søren

    2002-01-01

    and AUC by Pearson's correlation coefficient, and pairs of correlation coefficients were compared by an asymptotic Wald-type test. RESULTS: AUC varied five-fold despite near-equal dosing. Pearson's correlation coefficient for trough level, 1, 2, 3, 4, and 6 h were 0.84, 0.60, 0.81, 0.95, 0.95, and 0...

  13. Building the Petascale National Environmental Research Interoperability Data Platform (NERDIP): Minimizing the 'Trough of Disillusionment' and Accelerating Pathways to the 'Plateau of Productivity'

    Science.gov (United States)

    Wyborn, L. A.; Evans, B. J. K.

    2015-12-01

    The National Computational Infrastructure (NCI) at the Australian National University (ANU) has evolved to become Australia's peak computing centre for national computational and Data-intensive Earth system science. More recently NCI collocated 10 Petabytes of 34 major national and international environmental, climate, earth system, geophysics and astronomy data collections to create the National Environmental Research Interoperability Data Platform (NERDIP). Spatial scales of the collections range from global to local ultra-high resolution, whilst sizes range from 3PB down to a few GB. The data is highly connected to both NCI HPC and cloud resources via low latency internal networks with massive bandwidth. Now that the collections are collocated on a single data platform, the 'Hype' and expectations around potential use cases for the NERDIP are high. Not unexpected issues are emerging such as access, licensing issues, ownership, and incompatible data standards. Many communities are standardised within their domain, but achieving true interdisciplinary science will require all communities to move towards open interoperable data formats such as NetCDF4/HDF5. This transition will impact on software using proprietary or non-open standards. But before we reach the 'Plateau of Productivity', there needs to be greater 'Enlightenment' of users to encourage them to realise that this unprecedented Earth system science platform provides a rich mine of opportunities for discovery and innovation for a diverse range of both domain-specific and interdisciplinary investigations including climate and weather research, impact analysis, environment, remote sensing and geophysics and develop new and innovative interdisciplinary use cases that will guide those architecting the system and help minimise the amplitude of the 'Trough of Disillusionment' and ensure greater productivity and uptake of the collections that make NERDIP unique in the next generation of Data-intensive Science.

  14. Variability of Voriconazole Trough Levels in Haematological Patients: Influence of Comedications with cytochrome P450(CYP) Inhibitors and/or with CYP Inhibitors plus CYP Inducers.

    Science.gov (United States)

    Cojutti, Piergiorgio; Candoni, Anna; Forghieri, Fabio; Isola, Miriam; Zannier, Maria Elena; Bigliardi, Sara; Luppi, Mario; Fanin, Renato; Pea, Federico

    2016-06-01

    Voriconazole plasma exposure greatly varies among haematological patients. The purpose of this study was to identify the magnitude of influence of comedications with CYP inhibitors and/or with CYP inhibitors plus CYP inducers on voriconazole trough level (Cmin ). Voriconazole Cmin was retrospectively assessed among haematological patients who underwent therapeutic drug monitoring (TDM). Univariate and multivariate linear mixed-effect regression analyses were performed to identify the independent predictors of normalized Cmin . Of the 83 included patients, 35 had comedications with CYP inhibitors (omeprazole or pantoprazole) and 21 with CYP inhibitors (omeprazole or pantoprazole) plus CYP inducers (methylprednisolone, dexamethasone, phenobarbital, rifampin or carbamazepine). Median Cmin value (n = 199) was 2.4 mg/L with a wide range of distribution (voriconazole Cmin value was significantly higher in the presence of CYP inhibitors (4.20 mg/L, 3.23-5.51 mg/L) than either in the absence of interacting cotreatments (2.55 mg/L, 1.54-3.47 mg/L) or in the presence of CYP inhibitors plus CYP inducers (2.16 mg/L, 1.19-3.09 mg/L). The presence of CYP inhibitors was highly significantly associated with Cmin >5.5 mg/L (OR: 23.22, 95% CI: 3.01-179.09, p = 0.003). No significant association emerged when CYP inhibitors were coadministered with CYP inducers (OR: 3.53, 95% CI: 0.36-34.95, p = 0.280). The amount of expected Cmin increase was significantly influenced by both the type and the dose of the administered proton pump inhibitor. The study highlights that the benefit from TDM of voriconazole may be maximal in those patients who are cotreated with CYP inhibitors and/or with CYP inhibitors plus CYP inducers, especially when receiving proton pump inhibitors (PPIs) at very high dosages intravenously. © 2015 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  15. San Andreas Fault dip, Peninsular Ranges mafic lower crust and partial melt in the Salton Trough, Southern California, from ambient-noise tomography

    Science.gov (United States)

    Barak, Shahar; Klemperer, Simon L.; Lawrence, Jesse F.

    2015-11-01

    We use ambient-noise tomography to improve CVM-H11.9, a community velocity model of southern California. Our new 3-D shear-velocity model with 0.05° x 0.05° lateral and 1 km vertical blocks reveals new structure beneath the San Andreas Fault (SAF), Peninsular Ranges batholith (PRB), southern Sierra Nevada batholith (SNB), and the Salton Trough (ST). We use 4 years of data recorded on 849 broadband stations, vastly more than previous studies and including our own broadband Salton Seismic Imaging Project, a 40 station transect across the ST, as well as other campaign stations in both Mexico and the United States. Mean lower crust and upper mantle wave speeds (3.6 km/s at 20 km, 4.2 km/s at 40 km) are low by global standards. Across the SAF, southeast of San Gorgonio Pass, we observe vertical to steeply dipping lateral velocity contrasts that extend beneath the Moho. Beneath the western PRB and westernmost southern SNB, we observe relatively high shear velocities (≥3.8 km/s) in the lower crust that we interpret as the mafic roots of the overlying arc. Relatively high-velocity upper mantle (up to ˜4.5 km/s) may be part of the intact arc, or possibly a remnant of the Farallon plate. Beneath the ST, we observe zones of low shear-velocity in the lower crust and upper mantle which permit up to ˜4.5% melt in the lower crust and up to ˜6% melt in the upper mantle, depending on the assumed composition and pore geometry. Our results preclude the existence of older continental crust beneath the ST and support the creation of new crust beneath the ST.

  16. Assessment of the Long-Term Trends of Transient Inverted Troughs within the North American Monsoon Region: Mechanisms and Implications for Warm Season Precipitation

    Science.gov (United States)

    Castro, C. L.; Lahmers, T.; Ser